JPH0262932A - Data averaging processing method for lens tester - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a data averaging processing method for a lens tester, and more particularly to f-equalization processing, that is, rounding processing, of contrast data that is continuously obtained in large numbers due to noise or the like. [Prior Art] Generally, optical lenses such as photographic lenses are subjected to a final inspection (performance inspection) by a projection test during mass production. This projection test is a test in which an operator visually checks a chart image projected by a lens to be tested (test lens) to confirm the resolving power of the lens to be tested. Figure 31 shows the projection test l! 1' indicates a lamp such as a halogen lamp as a light source, and 2' indicates a lamp l.
3' is a transmission chart 4' is a test lens, and 5" is a projection plate. The transmission chart 3' is a transparent glass plate with various sizes on the surface. A predetermined pattern consisting of a combination of vertical line rows and horizontal line rows with a pitch is drawn as a light-opaque pattern by vapor deposition of chromium, etc. The size of the line rows (width and pitch of the lines) in this pattern corresponds to the resolution. Then, the resolving power is evaluated as, for example, 100/I11 from the minimum pitch line array that can be seen separately in the chart image projected onto the projection plate 5'.The light beam from the lamp 1' is passed through the condenser lens 2'. The light is focused and transmitted through the transmission chart 3' by illuminating it from the back side.The transmission chart 3' formed by this transmitted light
The image is enlarged and projected by the test lens 4' onto a projection plate 5' placed at a position 40 to 50 times the focal length of the test lens 4'. At this time, if the incident angle θ2 of the illumination light from the condenser lens 2' to the chart 3' is smaller than the incident angle θ1 of the light flux of the chart image by the test lens 4', as shown in the figure, the test lens 4' The incident angle 0□ must be sufficiently large because the result is a narrowed-down image. The operator finely adjusts the position of the test lens 4' in the optical axis direction to align it with the focused projection plate 5' at the center of the bipedal chart image, and then the image is projected onto the projection plate 5'. Visually check whether the chart at a predetermined pitch at a predetermined position in the chart image is separated (in other words, whether the chart has a predetermined resolution at a predetermined position in the chart image), and determine whether the lens to be tested is good or not. Inspect. However, such projection tests have poor workability because they must be performed in a dark room.
If the focal length of the lens to be tested is long, it requires a large viewing room and requires a large amount of equipment costs.Furthermore, the condenser lens needs to be large in diameter and bright, and it requires skill to visually check the chart image. Even if the operator is trained, stable inspection with a certain level of accuracy cannot be expected.
There were a number of problems such as: For this reason, the present applicant first developed a lens holder that rotatably holds the lens to be tested, and a lattice chart at a predetermined pitch from on-axis and off-axis to the lens to be tested held in the lens holder. A chart detected by an optical system that allows the light transmitted through the optical system to enter the optical system, and a detection means that is disposed in a drive circuit that moves in the optical axis direction of the test lens in front of each optical path of the on-axis and off-axis light by the optical system. a contrast measuring means for calculating contrast based on the image; and an operation control means for controlling the rotational drive of the lens holder and the operation of the contrast measuring means in order to measure the contrast at a predetermined position of the image of the test lens; A lens tester comprising a determination unit that determines the quality of a lens to be tested by comparing the contrast measured by a contrast measuring means with a predetermined determination standard, and a display unit that displays the determination result by the determination unit. proposed. [Problems to be Solved by the Invention] However, in the lens tester as described above, a CCD sensor or the like is used as a detection means for detecting the chart image of the lattice chart formed by the tested lens. Since the measurement data obtained by such a CCD sensor etc. is subject to variations due to the influence of noise, etc., or contains noise, etc., the above-mentioned judgment unit uses this as a contrast and uses it for judgment. There was a gap where comparison with a standard would result in an inaccurate determination of the quality of the lens to be tested. [Purpose of Issue 11] This invention has been made in view of the above background, and is a data average of a lens tester that can reduce data distortion due to noise components and round it into stable data. The purpose of this research is to provide a method for chemical treatment. [Means for Solving the Problems] Therefore, the data averaging processing method of a lens tester according to the present invention detects a chart image of a lattice chart formed by a tested lens by moving it stepwise in the optical axis direction of the tested lens. In a lens tester, the contrast of the image of the lattice chart is continuously obtained in large numbers based on the chart image detection result by the detection means, using a contrast measuring means that operates in conjunction with the step movement of the detection means. When a large number of contrasts are continuously obtained from the contrast measuring means, a predetermined number of contrasts are collected, an average value is calculated, and this is used as true measurement data, and the predetermined number of contrasts are collected in a moving step of the detection means. At each step, the contrast newly obtained at that step is shifted by a predetermined number in the direction of incorporating it. [Embodiments of the Invention] Hereinafter, embodiments of this invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram showing a schematic configuration of a lens tester to which a preferred embodiment of the data averaging method according to the present invention is applied. "Outline of Lens Tester LT" (Constitution) The Lens Tester LT consists of a lens mount section lO1 as a lens holding section, an optical system 2, a contrast measuring section 3 as a contrast measuring means, which is composed of a sensor section 31 and an arithmetic circuit 32. , a control section 4 as an operation control means, a determination section 5, a display section 6, and so on.The control section 4 and the determination section 5 are composed of one microcomputer. In the example, the lens tester LT is VC-connected to a computer as shown in FIG. 26 to form a lens tester system, which will be explained in detail later. The lens 1 to be tested is held in a predetermined position so as to be rotatable about the optical axis of the lens 1. The optical system 2 is attached to the lens 1 held by the lens mount 1O along the optical axis of the lens 1 to be tested. The light (on-axis light LA) that has passed through the chart CA with a predetermined lattice pitch from on-axis is incident, and the light that has passed through the chart CZ with a predetermined lattice pitch from off-axis that has a predetermined angle with the optical axis is incident (on-axis light L).
Z) is incident. The contrast measurement unit 3 uses a chart C formed by passing the on-axis and off-axis lights LA-LZ from the optical system 2 through the lens to be tested 1 held in the lens mount unit IO.
Each CCD sensor (on-axis sensor 31A and off-axis sensor 31Z) of the CCD sensor unit 31 scans the A-CZ image in the pitch direction of the chart image, converts the brightness of the chart image into an electrical signal, and converts the brightness of the chart image into an electrical signal. The signals are computed by the arithmetic circuit 32 (on-axis arithmetic circuit 32A and off-axis arithmetic circuit 32B) to calculate (that is, measure) the contrast of the on-axis and off-axis chart images. The control unit 4 controls each CCD sensor 31 of the CCD sensor unit 31.
A.312 is moved in the optical axis direction of the test lens l to measure the contrast of the on-axis and off-axis chart images at multiple locations in the optical axis direction of the test lens l, and the lens mount part By driving lO, the test lens 1 is rotated around its tip axis to change the off-axis measurement point, and the pitch direction of the chart image relative to the test lens l on the axis is changed. The contrast of the chart image is measured at multiple predetermined off-axis positions at multiple locations in the optical axis direction of the detection lens L, and further, from the on-axis contrast measurement results obtained from the above measurements, the contrast at each measurement point is determined. The on-axis and off-axis CCD sensors 31A and 31Z are fixed at the average position of the optical axis-hi position where the contrast is maximum. II. The off-axis sensor 3 is placed at a distance from the test lens l that is equal to the average distance between the test lens l and the on-axis sensor 31A, which indicates the maximum contrast at each measuring point on the axis.
1Z is also fixed), and the test lens L is rotated to measure the contrast of the chart image at each off-axis measurement point.
It controls the movement of the CCD sensors 31A and 31Z of the sensor section 31 of the contrast measurement section 3, the measurement of contrast, and the drive of the lens mount section 1O (rotation of the lens 1 to be tested). The determination unit 5 is controlled by the operation control unit 4 and compares the contrast value of the chart image obtained by the contrast measurement unit 3 with a predetermined determination reference value, and also compares the contrast value of the chart image obtained by the contrast measurement unit 3 with a predetermined determination reference value. The amount of mutual deviation in the optical axis direction of each off-axis measurement point is compared with a predetermined criterion i amount, and if it exceeds one criterion, it is determined to be defective and the quality of the lens 1 to be tested is determined. Furthermore, if the lens to be tested is defective, a predetermined value is determined based on the contrast value of each measurement point or the mutual deviation in the optical axis direction of the on-axis and off-axis measurement points that indicate the maximum contrast value. The details of the defect are derived using the analytical calculation method. The display unit 6 displays the determination result by the determination unit 5 and the derived defect details by lighting the LEDs arranged thereon. Next, the configuration and operation of each of the above components will be explained in detail in order. "Lens mount section lO" (Configuration) Fig. 2 is a plan view of the lens mount section 10, and Fig. 3 is a plan view of the lens mount section 10.
It is a sectional view taken along ■-■. In the figure, 100 is the chassis of the lens tester LT (not shown in FIG. 2), 11 is a mount for positioning and holding the lens to be tested, and 101 is fixed to the chassis 100 that rotatably supports the mount 11. Bearing boss, 15
17 is an air cylinder that drives the lock mechanism 15; 18 is a locking mechanism that fixes the lens to be tested on the mount 11;
is a DC motor that rotates the mount 11. The mount 11 has an opening formed in the center of a disk-shaped substrate 12 for passage of inspection light, and a lens mounting section 13 on which the lens 1 to be tested can be positioned and mounted on the upper surface of the substrate 12.
．． The bearing boss 101 has a substantially disk-shaped appearance with a fitting portion 14 for fitting the bearing boss 101 formed on the lower surface thereof. A gear 12A is formed on the outer peripheral end surface of the substrate 12 over the entire circumference, and the lens 1 to be tested is placed at three opposing locations around the lens a holder 13 on the top surface of the substrate 12. A locking mechanism 15 for fixing to the mounting portion 13 is also provided. The fitting portion 14 is fitted into a bearing boss lot fixed to the chassis 100 via a bearing 102, and is rotatably installed in the chassis 100. The lens mounting portion 13 has a reference surface 13A on its upper surface, and is provided with positioning in the front-back and left-right directions (not shown). The flange for attaching the lens to the camera body) is brought into contact with the flange) and the position of the lens 1 to be tested relative to the mount 11 is determined (
In other words, it is configured to be in a positioned state. The DC motor 18 is fixed to the lower surface of the chassis 100 on the side of the mount 11, with its spindle 18A facing upward. Spindle 1 that penetrates chassis lOO and protrudes upward
A gear 181 is fitted and fixed to the upper end of 8A.
1 and the idle gear 16, and the idle gear 16 also meshes with the gear 12A on the outer periphery of the substrate 12 of the mount 11, and the mount 11 is rotated by the rotation of the DC motor 18.
or rotationally driven. The locking mechanism 15 is rotatably supported by a link plate 152 or approximately at the center of the link plate 152 on the side surface of a post 151 erected on the upper surface of the base plate 12.
A pin 152A fixed to the tip of the link plate 152 is fitted into a notch 153A of the lock plate 153, so that when the link plate 152 rotates, the lock plate 153 also rotates. The lock plate 153 has a plate shape with a predetermined thickness, and has a notch 153A open at the upper end and a protruding claw 153B at one side end, with the claw 153B on the lens mounting section 13 side. It is rotatably supported by a post 151 on the lower end side. Further, the link plate 152 and the lock plate 153 are connected by a spring 154 on the outside of their respective pivot positions (on the side opposite to the lens storage section 13), and the spring 154 or the lock plate 153 is connected to each other by a spring 154. is pulled and biased against the link plate 152 in a direction that causes the claw 153B to rotate toward the lens mounting portion 13 side. Is the rotation of the lock plate 153 regulated by contacting the claw 153B or the upper surface (reference surface 13A) of the lens mounting portion 13? At this time, the force pressing the claw 153B or the reference surface 13A is It is set to provide a predetermined pressing force sufficient to hold l. The air cylinder 17 is installed on the chassis 100 outside the link plate 152 with the position of the rod 17A corresponding to the upper side of the pivot point of the link plate 152, and the air cylinder 17 is driven to extend the rod 17A. When the rod 17A is
Press the upper end of 52 and rotate it (rotate so that the upper end moves toward the lens mounting section 13 side and the lower end moves toward the side opposite to the lens storage section 13), and lock the lock plate 15 via the pin 152A.
3 in a direction in which the claw 153B moves away from the lens mounting portion 13 (indicated by an arrow in the figure). In addition, in the figure, the air cylinder 17 is shown for only one lock mechanism 15, or it is arranged similarly for the other lock mechanism 15, or it is arranged for both lock mechanisms 15.
It is sufficient if they are connected by a link mechanism or the like so that they operate synchronously. (Function) Then, the air cylinder 17 is driven to lock the lock plate 1.
53 in the direction in which the claw 153B moves away from the lens mounting section 13, the reference surface 13A of the lens mounting section 13
It becomes possible to move (or remove) the lens to be examined l onto the top. In this state, when the lens 1 to be tested is positioned on the reference surface 13A and the air cylinder 17 is driven in the opposite direction to release the pressure on the link plate 152, the spring 15
The lock plate 153 is rotated by the tensile force of step 4, and the claw 153B or the flange LA of the test lens l is pressed onto the lens mounting section 13, so that the test lens l is placed on the reference surface 13A (that is, on the mount 11). ) to be fixed. Furthermore, by rotating the DC motor 18 to drive the mount 11, the lens l to be tested fixed on the mount 11 can be rotated around its optical axis.
Moreover, it can be stopped at any position (angle). The drive control of the air cylinder 17 and the DC motor 18 is performed by a control section 4, which will be described later. "Optical System 2" (Configuration) As shown in No. 1121, the optical system 2 includes a light source section 21 that forms two light beams, axial light and off-axis light, and a light source that transmits each light beam from the light source section. Each chart CA-CZ is a transmission grating with a predetermined pitch arranged at a position where the optical path of each light beam (on-axis light LA and off-axis light LZ) passes through the chart CA-CZ and the test lens 1. A mirror 22 that reflects and refracts the light and guides it to a contrast measuring section 3, which will be described later.
-23, It is composed of collimator lenses 24, 24 arranged on the respective light beam optical paths. As shown in FIG. 4, the light source unit 21 includes a halogen lamp 211. The halogen lamp 2
Two filters 212 and 213, a condenser lens 214, a diffuser plate 215, an on-axis fixed half mirror 216, and an off-axis movable mirror 217 are arranged in the order described above to adjust the light from 11 to a predetermined spectral characteristic. It is configured. A parabolic reflecting plate 211A is provided on the back side of the halogen lamp 211 (the side opposite to the light beam emission side), and focuses the light from the halogen lamp 211 at a predetermined position (indicated by f in the figure). It looks like this. And that focus level 2? Two filters, an infrared absorption filter 212 and a color correction filter 213, are arranged in the order of a condenser lens 214 and a diffuser plate 215 in front of the optical path from f. In front of the optical path from the diffuser plate 215, an on-axis fixed half mirror 216 is fixedly arranged at an angle of 45° with respect to the optical path.
Next, an off-axis movable mirror 217 is arranged. The off-axis movable mirror 217 has its angle adjusted in the same plane and is movable back and forth in the direction of the light beam from the halogen lamp 211. It is configured so that the angle of light can be adjusted. Separate charts CA-CZ or chassis 10 are placed in front of the test lens l on the optical path of the on-axis and off-axis lights LA-LZ emitted from the light source section 21 (that is, on the light source section 21 side of the mount 11).
It is fixed at 0. As shown in Fig. 6, the charts CA-CZ are arranged at a predetermined pitch (P) in one direction on a flat glass substrate through which light can pass.
This is a rectangular wave grating formed by vapor-depositing a plurality of line parts or ROMs that are opaque to light. Then, the position where the axial light LA is transmitted (i.e., the lens to be tested l
On the optical axis), there is an on-axis chart CA of P = 1/20 m-, and at a position where off-axis light LZ passes through, there is an on-axis chart CA of P = 1/IO+.
Off-axis charts CZ of s-kai are arranged respectively. In addition, the arrangement direction of each chart CA-CZ is such that the pitch direction (direction perpendicular to the scored line) is radial from the center of the test lens l in the off-axis chart CZ, and the direction in which the on-axis chart CA is also arranged. It is arranged in the same direction as this off-axis chart CZ. The mirrors 22 and 23 fix the on-axis mirror 22 at a predetermined position on the optical path extension of the on-axis light LA via the on-axis chart CA and the test lens 1, and also fix the on-axis mirror 22 at a predetermined position on the optical path extension of the on-axis light LA via the on-axis chart CA and the test lens 1. The off-axis mirror 23 is arranged at a predetermined position on the optical path extension of the off-axis light LZ. The axial mirror 22 transmits axial light L along the optical axis of the test lens L.
A? On-axis sensor 31A of contrast measuring section 3, which will be described later
The light beam is fixedly installed at a predetermined position on the optical axis of the lens 1 to be tested at an angle of 45 degrees with respect to the optical axis of the lens 1 to be tested so as to reflect at right angles toward the lens 1. As shown in FIGS. 7 and 8, the off-axis mirror 23 is attached to a guide rail 231 fixed to the chassis 100 via a slide base 232 and a mirror holder 233, so that the distance and installation from the optical axis of the lens l to be tested are determined. It is installed so that the angle can be adjusted. The guide rail 231 is fixed to the chassis 100 horizontally with its longitudinal direction facing an off-axis sensor 31Z of the contrast measuring section 3, which will be described later. The slide base 232 is slidably and irremovably fitted into the guide rail 231 on its lower surface, and is slidably movable along the longitudinal direction of the guide rail 231.
It can be fixed at a predetermined position a by a locking mechanism (not shown). The mirror holder 233 is integrally and irremovably fitted to the slide base 232, and is slidable and rotatable in the fitting portion 234 thereof. This slide base 23
The rotational position of the mirror holder 233 relative to the mirror holder 2 can also be fixed at any angle by a fixing mechanism (not shown). The direction of the rotation axis of the mirror holder 233 is a horizontal direction perpendicular to the sliding direction of the off-axis mirror 23 (that is, the longitudinal direction of the guide rail 231). or,
A mirror holding part 233A is provided upright on the upper surface of the mirror holder 233, and a mounting hole 233B is formed through the mirror holding part 233A near the upper end thereof. A cylindrical mounting bar 23A or its end face is adhesively fixed to the back surface of the off-axis mirror 23, and when the mounting bar 23A is fitted into the mounting hole 233B of the mirror holter 233, the mounting bar 23A is Book set screw 233
By tightening from the orthogonal direction at C, the mirror holder 2
An off-axis mirror 23 is fixed to 33. This configuration allows the off-axis mirror 23 to be fixed without being distorted. In addition, in FIGS. 7 and 8, the axis of the mirror 23 is at an angle perpendicular to the optical axis direction, or in fact, it is installed inclined at a predetermined angle as shown in FIG. The collimator lens 24 is placed on an optical path that is refracted by the -h ankle mirror 22 and the off-axis mirror 23 and goes toward the contrast measuring section 3, respectively.
The sensor section 31 is fixed to the chassis 100 via a unit base 313. (Function) The light source section 21 converts the light from the halogen lamp 211 into an infrared absorption filter 212 and a color correction filter 213.
As a result, the light has a predetermined spectral characteristic as shown in FIG. 5(d), and is emitted toward the test lens l as on-axis and off-axis light LA to LZ. FIGS. 5(a), (b), and (c) show the light source section 21 at 411.
There are graphs showing the emission spectral characteristics or transmission spectral characteristics of each component, and in each graph, the horizontal axis is the wavelength, and the vertical axis is the emissivity or transmittance. To explain each graph, (a) shows the emission spectral characteristics of the halogen lamp 211 alone. (b) is the transmission spectral characteristic of the color correction filter 212 alone, and the color correction filter 212 has a center transmission wavelength of 460
It becomes n+s. (c) shows the transmission spectral characteristics of the infrared absorption filter 213 alone, and has a 50% cut wavelength of 750n-. (d) shows the halogen lamp 211. Infrared absorption filter 2
This is the spectral characteristic of transmitted light when the 131 color correction filters 212 are combined as shown in FIG. That is, the light emitted from the light source has the spectral characteristics shown in (d). Light with this spectral characteristic is
CCD sensor 31A of the contrast measuring section 3, which will be described later.
In combination with the light-receiving spectral characteristics of 31Z (FIG. 5(e)), the spectral characteristics substantially match the visual sensitivity. The light processed to have such spectral characteristics is diffused by a diffusion plate 215 to blur the filament image of the halogen lamp 211, and approximately 50% of the light is converted into axial light LA by an axial fixed half mirror 216. ” is reflected at right angles in three directions. The light transmitted through the on-axis fixed half mirror 216 is reflected toward the road at a predetermined angle by the off-axis movable mirror 217, and becomes off-axis light LZ. As mentioned above, the off-axis movable mirror 217 is a moat that can move and rotate back and forth in a direction parallel to the light beam, and can change and adjust the angle of the off-axis light LZ with respect to the optical axis by changing and adjusting the angle. The external measurement position can be changed and it can be adapted to the type of lens l to be tested. On-axis and off-axis light beams LA and LZ from the light source section 21 are on-axis and off-axis light beams that have passed through the test lens l, which pass through the on-axis chart CA and the off-axis chart CZ and enter the test lens 1, respectively. The light beams LA-LZ are reflected by the on-axis mirror 22 and the off-axis mirror 23, respectively, and the imaging position is shortened by the collimator lens 24 to form a control lens, which will be described later.
The light enters the last measuring section 3. Note that the movement and rotation of the off-axis mirror 23 is performed by the light source unit 2 described above.
When the angle of the off-axis light LZ with respect to the optical axis is changed by adjusting the off-axis movable mirror 217 in step 1, the off-axis light LZ
is adjusted so that the light is incident on the sensor 31Z of the contrast measuring section 3. Below is the margin "Contrast all constant part 3" (Configuration) Contrast)
The sensor 431 has CCD sensors 31A and 312 arranged on the optical path of the sensor 431, respectively, and an arithmetic unit 32 that processes signals from the one-nucleus sensor unit 31 and two off-axis signals. The sensor section 31 includes on-axis and off-axis CCD sensors 31A.
312 is configured as "r fi" moving in the direction of the light beam, but its configuration is the same on the axis and off-axis, and by using the explanation IJJ on the upper side of the axis, the explanation IJ1 on the outside of the axis is omitted. It is constituted by an arithmetic circuit 32A that arithmetic processes the above-axis signal from the CCD sensor 31A of the sensor section 31, and an arithmetic circuit 32Z that arithmetic processes the out-axis signal from the CCD sensor 31Z of the sensor section 31. Its structure is the same on the 411 and off-axis as in the sensor section 31, and the explanation on the outside of the axis will be omitted by explaining the upper side of the axis.The sensor section 31 is shown in FIG. As shown in FIG. 10, which is a cross-sectional view along X-X, and threshold 111, which is a cross-sectional view along XI-XI, light '-''7: Receives the axial light LA introduced into the contrast measurement unit 3 by the system 2. A CCD sensor 31A, a sensor support 311 that holds the CCD sensor 31A. A slide base 312 to which an IT sensor board 311 is fixed. %r are arranged in a predetermined positional relationship on the unit base 313 to form an integrated unit. Two slide shafts 314A of linear bearings 314 are fixed to the unit base 313 parallel to the optical path (optical axis) of the light LA, and the slide shafts 314A of the linear bearings 314 are fixed in parallel to the optical path (optical axis) of the light LA.
Two slide pieces 314B are slidably fitted into each of the slide pieces 314A. The slide base 312 is installed on the unit base 313 by fitting and fixing the slide piece 314B to the lower surface thereof, and is movable in the optical path direction of the axis JZ light LA. In addition, an acid screw 315 is fixed to the approximately medium heat on the bottom surface,
The acid screw 315 has a screw shirt connected to the spindle of a pulse motor 316 fixed to the end face of the unit base 313 on the side opposite to the light LA incident side.
317 are screwed together. The sensor board 311 is an electric circuit board that detects (measures) the optical range of the image of the axial char (CA) caused by the axial light LA that has passed through the test lens as an analog signal. A CCD sensor 31A that senses and outputs an electrical signal corresponding to the light value, and the CCD sensor 3 (not shown)
It is composed of a 1A drive circuit and peripheral circuits such as a sample and Hall circuit. The CCD sensor 31A is a line sensor in which one pixel is arranged in one line, and is fixed on the 110th surface side of the sensor board 311, but the light receiving surface is perpendicular to the axial light LA, and the line direction is shown on the axial chart. It is vertically fixed to the slide base 312 in alignment with the pitch direction of the CA. In other words,
The direction of the pixel arrangement is the axis (on-axis char by two-dimensional LA)C
The sensor board 31 l is perpendicular to the grid direction of the image of A.
Provided for iiQ blood. Note that the collimator lens 24 of the optical system 2 described above is fixed to the front end of the unit base 313. The arithmetic circuit 32A is configured as shown in the block diagram shown in FIG. The sensing signal So is processed to output the contrast of the image of the on-axis char (CA). In other words, in this arithmetic circuit 32A, the CCD sensor 31A
is connected to the bypass filter 321 and the integration circuit 322 via the aforementioned sample and Hall 1 circuit (not shown), and the bypass filter 321 is connected to the absolute 111 circuit 3.
23. The absolute value circuit 323 is connected to an integration circuit 324, and the integration circuit 324 is connected to a sample and Hall 1 circuit 325. Further, one integrating circuit 322 is connected to a sample and Hall 1 circuit 326, and both of these sample and Hall 1 circuits 325 and 326 are connected to a division circuit 327. (Function) In the sensor f'f31, the rotation of the pulse motor 316 causes the slat base 312 to slide along the slide shaft 314A. That is, the CCD sensor 31A is driven to move in the optical axis direction of the axial light LA. The arithmetic circuit 32A is a CCD sensor 31A of the sensor section 31.
The optical image signal So sent from the The bypass filter 321 takes out the alternating current component in the optical image signal S. The absolute value circuit 323 rectifies the absolute value of the alternating current component, that is, the negative alternating current component, to the positive side by the bypass filter 321. The integrating circuit 324 outputs 1 sent from the absolute value circuit 323:
Integrate the ration pair fII over a given time. That is, the integrating circuit 324 integrates the alternating current component within the optical image signal So. On the other hand, the other integrating circuit 322
The optical image signal So sent from the CD sensor 31A is directly integrated for a predetermined time, and the integrating circuit 322 integrates the DC component of the optical image signal So. Note that each of the dipping circuits 322 and 324 is reset by a reset signal To, and its integration time is controlled by an integration signal T1. The sample and Hall 1 circuit 325 samples the integral (p'i) of the integration circuit 324 and sends it to the division circuit 327.Similarly, the sample and Hall 1 circuit 326 samples the integral value of the integration circuit 322 and sends it to the division circuit 327. The sampling timing is controlled by the sample signal T2.The division circuit 327 receives the optical image signal So from the integration circuit 324.
Execute division by dividing the integral value of the AC component within by the integral value of the DC component of the optical image signal So by the v1 division circuit 322,
The division result is output as the contrast of the lens 1 to be tested. The optical image signal So is a rectangular wave signal (the rectangular wave signal includes a DC component) since the axial signal CA is a rectangular grating. However, if Fourier transform is applied, the above rectangular wave signal can be expressed as a composite of several sine waves with very different frequencies. Therefore, the optical image signal So
will be explained by placing it in the sine wave signal S1 shown in FIG. In the figure, a is the maximum value of the sine wave signal S1, that is, the maximum amount of light, b is the minimum value of the sine wave signal S1, that is, the minimum amount of light, and T
is the period of the sine wave signal S1. The alternating current component of this sine wave signal S1 is expressed as follows, where ω is the angular velocity. Also, its DC component is. It is expressed as Here, assuming one period of the above AC component, integrate the AC component and the DC component, and take the ratio of their integral values. Therefore, the above equation (5) differs from the above-mentioned equation (2) in that it is 2
Although it is multiplied by the constant /π, it becomes the contrast itself. That is, in the arithmetic circuit 32A, the CCD of the sensor section 31
The optical image signal So sent from the sensor 31A is passed through the bypass filter 321. The AC component is integrated over a predetermined time by an integrating circuit 324 via an absolute value circuit 323,
The other integrator circuit 322 corrects that! i, component is integrated. Then, the division value of the AC component is divided by the integral value of the DC component by the division r i circuit 327, that is, the division shown in equation (5) is executed, and the result of the division becomes the contrast of the lens l to be tested. The above explanation has been made by replacing the optical image signal SO with the sine wave signal S1 shown in FIG.・Since the area ratio of the AC component to the DC component of the optical image signal 30 is calculated using 324, the same applies even if the optical image signal So is a rectangular wave signal containing many harmonic sine waves, and there are some problems. It's something that doesn't exist. Note that the drive control and calculation circuit 32A of the sensor section 31
The art arithmetic key control is performed by the control g# section. "Control Unit 4" (Configuration) The control unit 4 is configured by a microcomputer including a CPU and memory, together with a determination unit 5 to be described later. This control section 4 controls each section of the lens tester LT (lens mount section 10 and contrast IN fixing section 3) according to a predetermined control program 4A (shown in FIG. 17) in the memory.
It controls the operation of all contrast JIIJ constant operations. (Function) The control section 4 controls the CCD sensor 3 of the contrast measurement section 3.
1A is driven and controlled to move in the optical axis direction of the test lens 1, and the contrast of the chart image is measured at multiple locations in the optical axis direction of the test lens 1 on axis 2 and off-axis. Measuring the contrast of the chart image at a plurality of locations in the optical axis direction of the test lens by driving the lens holder 10 to rotate the test lens around its tip axis and changing off-axis measurement points. (Measurement 1) From the measurement results of Measurement 1, it is possible to know the following optical characteristics of the lens to be tested. (These measurement results are used as reference values. Judgment of quality by comparison is made from I determination section 5, which will be described later.) (1) Based on the change in the position on the optical axis where the contrast at each measurement point on the axis shows the maximum value, The degree of astigmatism can be detected. (2) The average position (V chest plane position) of the position on the optical axis where the contrast shows the maximum value at each measurement point on the axis is determined as the basis of the lens 1 to be tested. By comparing with the image plane position and image plane position, it is possible to detect over or under back focus of the lens 1 to be tested. (3) *Position in the optical axis direction where the contrast is maximum i at each measurement point outside of The degree of off-axis astigmatism can be detected by the change in. (4) At the off-axis measurement point, the position where the contrast shows the maximum value (i.e. the image plane position) and the on-axis image plane position can be detected. By comparing, it is possible to detect the curvature and inclination of the image plane. (5) From the difference in the contrast tfk maximum value at each measurement point of axis - H, the degree of axis 1-coma aberration can be detected. (6) ) Maximum contrast at each measurement point on the axis 1
From the average value of , it is possible to judge whether there is a contrast deficiency on the two axes. (7) The lack of contrast in some areas on the axis can be determined from the minimum value of the maximum contrast values at each measurement point on +b. (8) Insufficient off-axis contrast can be determined from the average value of the maximum value of contrast at each measurement point off-axis. (9) The degree of off-axis coma can be detected from the difference in the maximum value of contrast at each off-axis measurement point. For example, if the lens to be tested 1 is a lens for a camera using 35 mm film, the measurement point that makes such detection possible is the angle of view of the 35 l film (36 m x
24 + s■) diagonal angles (■ in Fig. 14)
, ■, ■, ■), and the off-axis position is a predetermined distance #h required for determination from the on-axis position (h = 15 mm in this example).
It is sufficient to measure it at . In addition, if the curvature/inclination is only detected by comparing the image plane position at the off-axis measurement point and the image plane position in 2, then the off-axis measurement points should be It's good in places. Next, the CCD sensor 31A is fixed at the average position of the positions on the optical axis where the contrast at each measurement point shows the maximum value based on the on-axis contrast measurement results obtained by the above measurement 1'), and the lens holding part The CCD sensor 31A of the contrast measuring stage 3 is driven to move so as to rotate the lens l to be tested around its optical axis by driving the lens 10 to measure the contrast of the chart image at a predetermined measuring point off-axis. and measurement of the contrast of the chart image, and controls the driving of the lens holding unit lO (rotation of the lens l to be tested). (δ1
1 constant 2) From the measurement results of measurement 2, (1) astigmatism in axis 2 can be detected from the difference in contrast values at each measurement point. (2) Insufficient contrast on the axis can be detected from the average value of contrast at each measurement point on the axis. (3) Partial deficiency in on-axis contrast can be detected from the minimum value of contrast at each measurement point on the axis. (4) Insufficient off-axis contrast can be determined from the average contrast value at each off-axis measurement point. (5) From the difference in contrast values at each off-axis measurement point,
Defects in off-axis contrast variation can be determined. For example, if the lens to be tested is a camera lens using 35m film and is of a type that does not rotate during focusing, such as a straight helicoid, the off-axis measurement point in this detection is at the image plane position. As shown in Figure 14, 3
Viewing angle of 51111 film (361m phoenix x24+u+)
At a predetermined distance from the on-axis position (indicated by In the example, it is sufficient to measure at the same position h = 15 mm as in measurement 1 above. 15m from the second position
Although the position is outside the viewing angle, it is effective for obtaining data such as the curvature of the field. In addition, in the case of a test lens l such as a rotating helicoid, where the lens rotates with focusing and the orientation of the lens is not partially corrected, measurements can be made in 12 directions (■ to @) at 30° intervals as shown in Figure 15. Good, Nao,
The distance from the measuring device to the measurement position on the axis on the image plane may be determined as appropriate depending on the angle of view of the lens 1 to be tested. Next, specific operation M control will be explained based on a flowchart. FIG. 16 is a flowchart of the control program 4A of control 8114 and the determination program 5A described later. This control program 4A is stored in the memory constituting the control section 4, as described above, and consists of a plurality of subprograms (subroutines). That is, this control program 4A includes initial setting subroutine 41.11 preparation subroutine 42.degree. contrast measurement subroutine 43. Contrast measurement subroutine 44. It is composed of a parts recovery & data transfer subroutine 45. Hereinafter, each subroutine will be explained according to the flow shown in the figure. The initial setting subroutine 41 sets the optical system 2 and the drive mechanism section 1 of the contrast measurement section 3, the display section 6 of the drive mechanism section 1, the memory in the microcomputer of the control section 4, etc. to their respective initial states. Note that this initial setting subroutine 41 is executed once only when the power source is turned on. The measurement preparation subroutine 42 checks the pneumatic pressure of each pneumatic mechanism, makes sure that the lens to be tested l is set in the lens mount lO, and clears the display that displays ``defective'' and ``defective''. , move the sensor board 311 of the sensor unit 31 to the initial set, that is, its scanning start position (reference position), and stop it, measure the amount of transmitted light of the lens to be tested, and check the dirt on each chart CA, CZ and the optical system. The contrast measurement subroutine 43, which checks for major abnormalities (for example, narrowing down), moves the sensor port 311 of the sensor unit 31 to the scanning start position (base position 71).
) to the subject (
Scan (move) in the direction of approaching Lens I and shortening the optical path.
In this embodiment, the scanning width (moving distance) of l scanning steps is set to I/+2 tx■, and the scanning speed is approximately 240 Step/Sec. Further, although the PALNU motor 316 is used as the power source for this scanning, a motor with an encoder or the like may also be used. As a result, a characteristic curve of the contrast value against the day focus amount as shown in Fig. 17 is obtained, and by calculating the numerical value 1;
IU is used for off-axis use. Furthermore, in the contrast) All determination subroutine 43, the contrast measurement is executed four times by rotating the lens to be tested and changing its measurement point. (Setting I) The contrast measurement subroutine 44 sets the on-axis and off-axis sensor boards to the average on-axis image plane position. This corresponds to setting each CCD sensor outside the 9-axis axis to the film (designed value) that is focused at the center. Then, the on-axis and off-axis contrasts are measured in several predetermined directions (measurement 2 described above). In other words, in the case of a test lens of a type in which the lens does not rotate, such as a linear helicoid, the contrast is measured in eight directions shown in FIG. For a type of lens to be tested in which the orientation of the rotating helicoid lens is not constant, measurements are taken in 12 directions as shown in FIG. The measurement direction is changed by controlling the rotation of the lens mount section 1O depending on the type of the lens 1 to be tested. The parts restoration & data transfer subroutine 45 returns the stopping position of the lens mount sio to the predetermined initial position, releases the locking mechanism 15, and makes the test lens l ready for removal from the lens tester LT. The measured values are output to the personal computer section PC (described later), and further,
If the measured contrast is lower than the previously measured value, air is blown onto the char) CA and CZ from one side and suctioned from the other side to clean the char) CA and CZ. Next, each major subroutine will be explained in detail. The control/last u constant subroutine 43 is a subroutine that searches for the focus position (image plane position) on the axis and off-axis. The 1Ili constant of contrast is determined by two optical paths LA-LZ, one on-axis and one off-axis with respect to the lens 1 to be tested, as shown in FIG.
For each off-axis sensor board (CC
D sensor 31A. 31 Z). Each CCD sensor 31A・
312 moves by l scanning steps every time the contrast is measured by -.degree. As a result, contrast I to contrast 1lss (day focus '11
The contrast (direct characteristic curve) for : can be obtained. This contrast ratio l/1 is all stored in memory,
After the scanning of the predetermined scanning width wSS is completed, the contrast peak value 4 and its image plane position are calculated in the r1 constant section 5, which will be described later. Furthermore, the lens 1 to be tested is rotated to change the orientation of the lens with respect to the off-axis light beam LZ, and the above measurements are performed for the four force positions shown in FIG. Thereby, the contrast peak value and its Kira image plane position are determined for the predetermined direction. FIG. 18 is a flowchart of the contrast measurement subroutine 43 shown in FIG. 16. Each process (procedure) will be explained below according to the flowchart in the figure. In the process [+, ], the sensor section 31 and the calculation section 32
Measure the on-axis and off-axis contrast by. process

[21] In step [21], the contrast measured in process [11] is converted into a digital quantity by an A/D converter (not shown) disposed after the calculation step 32. In process [31], the contrast converted into a digital amount in process [2] is transferred to Do of the scanning average register group provided in the control unit 4. In process [41], the scan average register group in the control JLffiA calculates the scan average, and the calculation result is stored in a predetermined location in the memory. In process [51], in the scanning average register group, each data on each scanning average register is shifted to the respective register. In process [61], each CCD sensor is moved by one scanning step. In process [71], the scanning (movement) range of each CCD sensor is inspected. That is, it is checked whether the scanning amount (movement due to scanning) has reached the set number of scanning steps, and if scanning is completed, the process moves to the next process [8]. If scanning is not completed, return to process [11]. In process [81], the contrast peak value and its position are calculated from the contrast for a predetermined scanning width. In process [91], the lens mount is rotated by a predetermined angle to change the measurement orientation of the lens to be tested. In process [101], it is checked whether or not the contrast has been measured for all of the set orientations (four orientations). When the measurement is completed, the contrast measurement subroutine 43 is exited and the process returns to the main control program 4A. If the measurement has not yet been completed, process [111] is executed. In process [+11], the number of scanning steps is changed and set according to conditions, and the process returns to process [1]. This is intended to shorten the scanning time by reducing the number of scanning steps when a predetermined condition is met. Note that the loop consisting of processing [+1] to processing [7] constitutes one scanning step, and in this embodiment, the processing time of one scanning step is set to 4.096 ms. In the control section 4, scanning average calculation is performed using a scanning average register group during contrast measurement.Next, the operation of this scanning average will be explained. (Regarding Scanning Average Operation) FIG. 19 is a conceptual diagram of the scanning average register group. The scanning 11 register group includes eight registers D each having a predetermined number of bits. -Dr, and is installed in the control unit 4. The operation begins with the above-mentioned digital signal being sent to the control unit 4.
The data is transferred to the DO of the scanning 1L average register group in the register, and the average of the register Do=D+ is calculated. Then, this +1 uniform image i is transferred and stored in the memory as a contrast. Thereafter, each data in the scan 11 register group is shifted to the adjacent register. In other words, Do 401,
It is shifted from DI 4D7, -D6 to D+. In other words, since the logic of 8 = 11'A in binary notation is in the pipeline, high-speed calculations are performed in a circular manner by such processing. Furthermore, data shifting within the register is easy with the microcomputer that constitutes the control section 4. For these reasons, scanning average calculation can be easily and quickly processed. In addition,
In methods 1 and 2, the contrast peak position where the sum of the registers Do to DI is maximum causes a shift of four scanning steps from the sensor board position at the time when data is taken into DO. However, since this shift is always 1'M, the peak position may be determined by four scanning steps. First 1 to 7 pieces of data to be imported into register DO]
1, that is, until the scan average register group Do=DI becomes FUI,L, the averaged contrast of the scans is considerably lower than the actually measured contrast. However, since the measured value of this part corresponds to the bottom part of the contrast curve shown in FIG. 17, there is no problem, and the contrast obtained by taking the scanning average is always a value lower than the actual measured value, causing an error. However, this error from the actual measured current can be reduced by increasing the number of scanning steps, thereby making its influence negligible. In practice, the number of scanning steps in the scanning width wSS amounts to 300 to 1000 steps. Since 1 scanning step is 4.096 Ils, it takes about 1 second to 4 seconds. The contrast peak value and its position are found by repeatedly comparing the contrast values for all contrast data for each step stored in the memory.Depending on the number of scanning steps, the maximum value is about 10.
This means that the comparison will be repeated 00 times, and in this embodiment, the control f
Since f&4 operates with a 2 MHz clock, approximately 100 IIs is required to process the comparison. (About shortening the scanning time) In the contrast A11l constant subroutine 43, the 14th
In the figure, the contrast is measured in each predetermined direction shown in (O20, This method reduces the scanning width based on a predetermined procedure without performing a single scan.This aims to shorten the scanning time. When there is a large difference in changes H and H due to variations in fb at time and changes in the measurement points of the image plane in each lens under test, and the name of the song is larger. (2) When the off-axis image plane of the lens under test is If the tilt is small or there is no need to investigate. (3) Investigate changes due to the orientation of the central image plane of the test lens,
f - If only the equiaxial image plane needs to be measured. FIG. 20 is a conceptual diagram illustrating shortening of scanning time. In the figure, the horizontal axis indicates the scanning direction of the sensor board, and the vertical axis indicates the progression of scanning time downward. Scanning of the sensor board is performed four times in four predetermined directions. First, if the sensor board is scanned in direction (1) in 800 scanning steps, then in the next direction (2), the peak found in direction (2) Scan the position plus a predetermined scanning width -SH (this is, for example, 200 scanning steps). - If the peak position in the direction (2) of time II is 400 scanning steps 11, then the scanning in the direction (2) of two times [1 will only require 600 scanning steps. Similarly, there are 400 scanning steps in the third direction (3) and 400 scanning steps in the fourth direction (2). In this way, 4 directions 4
Each scan is a total of 2,200 scan steps, compared to a total of 3,200 scan steps if all four directions were scanned in four predetermined 800 scan steps without using this method, or about 4 times in time. It is reduced by N seconds. Judgment Unit 5J (Structure) The judgment unit 5 is composed of a microcomputer including a CPU and a memory together with the control unit 4 described above.In addition, the judgment unit 5 includes two memory cells for temporarily storing the two judgment results. Two judgment registers DSO and DSI (not shown) each consisting of 8 bits are provided.
The reason why there are two fixed registers, oso5 and DSI, is because...
This is because it cannot handle the amount of data to be processed. Furthermore, the memory of the microcomputer that constitutes the determination section 5 together with the control section 4 is used as a display control memory for controlling the display section 6, which will be described later. (Function) The determination unit 5 determines the contrast value at each measurement point of the lens 1 under test under the control of the control unit 4 described above, which is predetermined according to the control program 5A shown in Figure t516. The control program 5A, which performs pass/fail judgment by comparing with the standard standard, is stored in the memory constituting the internal standard part 5, and consists of a plurality of subprograms (subroutines).In other words, this VJm program 5A is composed of two judgment subroutines 51 and 52. Here, 1. By comparing the measurement result of measurement l (contrast measurement subroutine 43) with the judgment standard. Astigmatism on the (+) axis Aberration defects (defects due to abnormal changes in axial peak (A-ASU)) (2) Over or under pack focus defects (
Mechanical pack focus defect, excessive defect (fb large)
and insufficient defect (fb small)) (3) Off-axis astigmatism defect (off-axis image surface tilt defect (Z-ASU)) (4) Image surface curvature/tilting defect (under defect or A defect in which the off-axis image plane is too close to the lens side than the on-axis image plane (
(UND), and over-defect (0VER), in which the off-axis image plane is farther from the lens side than the axial north image plane (0VER)) (5) Axial coma aberration defect (defect due to abnormal change in best axial contrast (A- CON ) ) (6) On-axis contrast deficiency defect (average axial contrast value is too small (A-MTFLO)) (7) On-axis partial contrast deficiency defect ((TFPL in A-(8) Off-axis contrast deficiency Defective (Defect where the average off-axis contrast value is too small)
(Z-MTFLO)) (9) Determine off-axis coma aberration defect (abnormal change in best off-axis contrast (Z-COW)). 2. By comparing the measurement results of measurement 2 (contrast measurement subroutine 44) with (+) +ih, astigmatism defect (A-ASU) in
) (2) 輔-1-Contrast deficiency defect (A-MTFL
O) (3) A defect in which part of the on-axis contrast is insufficient (a defect in which a part of the off-axis contrast is small and an under-defect (U+H), a part of the off-axis contrast is small,
If the defect is excessive (0+H (4) Off-axis contrast deficiency (Z-MTFLO) (5) Off-axis contrast variation defect (Off-axis MTF changes drastically (Z-)IEN)) judge. The results of the 11 bipedal terms [1 and
8 (20 for good, l for bad), and the judgment results recorded in the judgment register and DSO/OS+ are displayed in the display control memory for each judgment subroutine 51 and 52. will be forwarded to. Then, the 1'4 constant results transferred and stored in the display control memory are displayed on each L
The ED is controlled to blink. That is, each LED of the display unit 6 displays the contents of the display control memory,
In other words, the configuration is such that blinking is controlled in accordance with the state (Q or 1) of each bit of DSO and O51 with a constant register, and each LED has a focus state corresponding to each bit. If the small is O, the light is turned off, and if it is ■, the light is turned on. Furthermore, the data used for the above determination is also sent to a personal computer section PC, which will be described later. Hereinafter, a detailed explanation will be given based on the flowchart. First, the two Y4 constant subroutines 51 and 52 that constitute the control program 5A will be explained according to the flow shown in FIG. The determination subroutine 51 calculates 111 degrees of on-axis astigmatism (astigmatism), coma, off-axis astigmatism (eccentricity), and coma from the results of the contrast measurement subroutine 43 described above. Furthermore, the equal image plane position on the axis “t”t ()IKNPPA)
The curvature of field is calculated by 111 from the difference between the image plane and the off-axis average image plane (IKNPPZ). Then, from the comparison of these calculation results with each of the items described below, determine whether the lens to be tested is good or bad and what is defective, and record the determination results in the The r4 redundancy subroutine 52 calculates the on-axis and off-axis contrast and the state of contrast change, and similarly to the rl judgment subroutine 1, calculates the results of these 31 calculations and each of The quality and defect content of the lens to be tested 1 are determined from the comparison, and the determination results are recorded in the determination registers DSO and O3+.
The r1 foot result is transferred and stored in the display control memory each time (for each determination subroutine 51 and 52) as described above.
Based on the stored contents of the display control memory, each LED of the display section 6 (to be described later) is controlled to blink. Because it is different, the control program 5A is used in the Shi/Z Tester LT.
, has many criteria. These judgments are sufficient (all of them are prefixed with STD in the control program 5A, 1-), % standard (1 white name is marked 4-1. Regarding the image plane), (base) 'i 4+ (5TDPP for i
A: ], Shipere + ib lx statue face TD
PPZ, -〇(be C-axis external image plane 5TOPPAU 2-axis", lower side limit 5TDPPAO + Okina 111 - side limit 5TOPPGU + off-axis Angu side limit 5TOPPGO + 11i + 1 outer 8-side limit, "2-leg each limit The lens 1 to be tested that is out of the range is determined to be defective in pack focus rb (mechanical focus position).
PSZ: +Ill external image F (j changes bit,
'' A lens to be tested that exceeds each image plane change limit is determined to be defective (astigmatism X:). Contrast change slightly STI]
MIIS^: Best axial contrast change limit S
TDMMSZ: There is a change limit for the best off-axis contrast, and a test lens that exceeds each of the above change limits is determined to have a coma aberration defect. The reference value for the minimum if-lid of contrast is ST
DMINA: Best axis” - Contrast limit 5TD
NINZ +Best off-axis contrast limit STDMN
[, A: Average axial contrast limiter at the image plane STDMNLZ: 1' Off-axis contrast limiter at the equator image plane STDMNFIZ: Average axis 1; Average offset of the off-axis contrast test at the image plane There is a limit of 1, and a lens to be tested that does not meet each of the above limits is determined to be defective due to undercontrast. In addition, the test lens that does not meet the average limit (STDMNH2) of the off-axis contrast on the average axial image plane is not only defective in the 4￥ fixed orientation, but also a lens with a large degree of defect in which the average value is also poor. It is determined that (About judgment action) ET'S 21 f; 41/4-4/4 ha,
FIG. 16 is a flowchart of the t71 constant subroutine 51. Hereinafter, the explanation will be given according to the flow of each process (procedure) shown in the figure. Processing [In IJ, from the 4 axial image plane positions (PPA) measured in 4 directions, PPAMAX maximum value PPAMIN: Iゎshi] IKNPPA: = l'Average value 5APPA: Maximum value and minimum value Find the difference between. In the processing PP, [2], the axial image plane change limit (5TDP
P, SA) and place J'l! [Compare the difference (5APPA) between the maximum value and minimum h/i calculated in step 13. Suke-1-
Maximum I1 than the image plane change limit (5TDPPSA)
If the difference between 6 and the minimum value (5APPA) is larger,
It is determined that the axis is defective (astigmatism), and the bit i of the 1st register (3rd hit rl of the determination register DSO) is detected.
Let be 1. The camera lens is called 11th rotation sentence. Generally does not produce astigmatism on the optical axis, however. If the camera lens is assembled with a poorly centered π1゛, astigmatism will appear on the optical axis -F, so
In the ``-2 process [2], a lens to be tested whose axial image plane misalignment varies by more than a predetermined value is determined to be an axial imbalance defect. Here, 1: A' place JI+! [2] The defect display will be explained by taking as an example the case in which an axis I-nian (astigmatism) defect is identified. In process [2], if it is determined that there is a defect in axial]nian (astigmatism), the corresponding bit ('rl
3 bits 11) of the fixed receipt taro SO become 1. Then, at the end of the 'rJI constant subroutine 51, the contents of the '11 constant register are transferred and stored in the display control memory (process [23] to be described later). 1 display section 6 based on data indicating
(No. 2514) LED 64A that indicates the defect
(A-ASU) is turned on. In process [3], set the shaft to the underside (5T
DPPAtl) and processing [+3, average 1f calculated by 11
t(HKNPPA)-. Average value (HKNPPA) than Suke and under limit (5TDPPAU)
) is larger, mechanical puck focus rb
It is determined that there is an under side abnormality, and the corresponding focus of the determination register (1 hit 1-1 of the determination register DSO) is set to 1. As a result, when the contents of the constant register in step 2 are transferred and stored in the display control memory, the LED 63A (large fb) of the display section 6, which indicates the defect, is turned on. Processing [In 4J, Ih1+L over side limit (8
TDPPAO) and treatment date] (1/i(H
KNPPA). And Suke 1. -Oh eight-
Average value ()IKN than side limit (5TDPPAO)
If PPA) is smaller than 1, it is determined that the mechanical pack focus fb is abnormal on the over side, and the corresponding focus (2 bits [1) of the determination register DSO] of the (2) determination register is set to 1. As a result, when the contents of the IZ determination register are transferred and stored in the display control memory, LE063B (fb small) of the display section 6, which indicates the defect in A1, is turned on. In process [51], the image plane (STDPPA) on the reference axis, that is, the sleeve 1 image plane position, and the 4L uniform pitch (HKNPPA) calculated in process [1], that is, the average axis on-axis image plane Find the difference (5AHKNA) between the image plane position and the image plane position. That is, (5TOPPA) - (HKNPPA) =
(5AHKNA) is calculated. In process 161, the average axis "-off-axis image corresponding to (-fi) the image plane (HKNPPA)) (+i < 5KPPZ) is determined. This allows measurements of off-axis contrast to be made at an off-axis image plane (5K
This is because there is peace of mind in doing so at PPZ). The fJS22 diagram shows the image plane position and processing [
Theory showing the relationship with the average image plane position calculated in 11 'JJ
It is a diagram. As shown in the figure, 17Q ii of the off-axis image plane
The deviation jii from the l value is calculated from the difference in image plane position (5A) IKNA ) calculated in processing [51] to (5AHKNA )
/ Cos O. In other words, Cos from the reference off-axis image plane (5TDPPZ)
θ is obtained. In addition, -7:, calculation of the angle function as in -1- is 11
In the microcomputer that constitutes the fixed section 5, the calculation program becomes complicated, and the number of program steps tends to increase unnecessarily. Therefore, in this embodiment, the calculations described in 2 are rounded to 1 arithmetic. In processing [7], the one-way limit of the off-axis image plane)
(5KPPZU) t, t-7<one direction') E
(5KPpzo). That is, in process [6], the off-axis image plane (5KPPZ) calculated by 1,
One-way deformation W i+i of the off-axis image plane: (5TDW[
I) , Off-axis Q surface (7) O /' One-way tolerance: I' + (5TDWO) to (5KPPZU) ” (5KPPZ) + (5T
DWU) (5KPPZO) = (5KPPZ) (
5TDWO) is required. In process [81], (5KPPZO) is checked, and if the value is negative, (5KPPZO) is set to O. This is to eliminate the negative (l/i) and facilitate calculation processing in the IJl constant section 5. In process [9], four off-axis image plane positions ( PρZ), PPZMAX: Maximum value PPZMIN: Minimum f1 tlKNPPZ: fj', JffiSAPPZ:
Find the difference between the maximum and minimum values. On processing day O1, off-axis image plane change limit) (5TDPP
SZ) and the difference (5APPZ) between the maximum value (11: calculated by 1,1 in step 91) and the minimum value (5APPZ). If the difference between the maximum value and the minimum value (5APPZ) is larger than the off-axis image plane change limit (Schoppsz), it is determined that the off-axis angle (astigmatism) is defective, and the correspondence of the judgment register is determined. Bit C
-r4 Set bit [1) of constant register DSI to 1. As a result, when the contents of the determination register are transferred and stored in the display control memory, the display section 6 which is an indication of the defect
Turn on LED 65C (Z-ASU). In processing fllJ, the one-way limit (5KPPZU) of the off-axis image plane calculated in processing [71] and processing [9
1, compare it with the 11-yen f〆i (HKNPPZ) calculated by :1. One-way limit of off-axis image plane (5KPPZ
If the average (/i(HKNPPZ)) is larger than the average (/i(HKNPPZ)
The 7 bits 11) of O are set to 1. As a result, when the contents of the L determination register are transferred and stored in the display control memory, the LED 65A (U
ND) lights up. In process [121], one side limit (5KPPZO) is applied to O7 of the off-axis image plane calculated by 1;1 in process [7], and process [
9] is compared with the average 11i (HKNPPZ) calculated by Ai. Off-axis image plane over one-way limit (5KPPZO
), if the average value (HKNPPZ) is smaller than
It is determined that there is an over-abnormality in which the image plane is curved to the over-side, and the corresponding bit in the determination register (8 bits 1 of the determination register DSO) is set to 1. As a result, when the contents of the determination register described in 1.1 are transferred and stored in the display control memory, LE065B (OVER
) lights up. In process ``131, 11 average value (
)IKNPPZ) In other words] is the equiaxial off-field position, and processing [
The difference (5A) IKNZ ) between the off-axis image plane position (5KPPZ) and the image plane position 2 calculated in [6] is calculated. That is, (H
KNPPZ) - (5KPPZ) = (5AHKNZ
) is calculated. In process [14], the off-axis image plane difference (5AHKNZ) calculated in process [131] is examined. In other words, the difference in off-axis image planes (5AHKNZ) is checked for 1 negative. If the difference between the off-axis image planes (5AHKNZ) is a positive value, it is considered that the off-axis image plane is on the underside of the 1st image plane. In this case, the off-axis undersize amount (PPZGU) is. (PPZGU) = (5A)IKNZ) X 2
+ (5APPZ) and the labor is calculated as 1. This off-axis under gl (PPZGU) is equal to the mean on-axis image plane (HKNPP
This off-axis underlit (PPZ) corresponds to the day focus amount of the off-axis image plane from
GU) and off-axis underside sum 7) (5TDPPZ
Compare with U). (5TDPPZU)
If off-axis under Et (PPZGU) is larger than , it is possible that there is eccentricity as well as curvature of the image plane to the under side, so it is determined that there is a combination defect of under abnormality and eccentric abnormality, and the l'-11 constant register is Corresponding bit (judgment register O
5 pittro) of S+ is set to 1. As a result, when the contents of the determination register are transferred and stored in the display control memory, the LED 65G (U
+H) lights up. - When the difference between the force and the off-axis image plane (5A)lKNZ) is a negative value, it is considered that the off-axis image plane is on the over side of the axial image plane. In this case, the off-axis over amount (PPZGO) is (PPZGO) = (5AHKNZ) x 2 +
(5APPZ) is calculated by 1. This off-axis over Qil (PPZGO) is equivalent to 2frτ of the day focus amount of the off-axis image plane from the image plane () The larger the outside over 1-1, the more it causes a decrease in contrast). Next, this off-axis over j11 (PPZGO
) and off-axis over m pieces min) (5TDPPZO). And off-axis over side limit (5TDP
If the off-axis overfit (PPZGO) is larger than the off-axis overfit (PPZO), eccentricity is also considered as well as curvature of the image plane toward the O/N- side, so it is determined that the combination of overfit and eccentricity abnormalities is defective, and the 'rlI determination is performed. The corresponding bit of the register (6 bits of judgment register DSI] 1) is set to 1. As a result, when the contents of the two-legged r1 constant register are transferred and stored in the display control memory, the LED 65H (0+H) of the display section 6 indicating the defect is turned on. Processing [In 15J, Jilt: Ii! for 4 force positions! 4 axes at the image plane position (1 nico/truss)
From (MTFA), MTFMAXA: Several people I MTFMINA: Minimum I) IKNMTF^・IIt average image 1 SAMTFA: Find the difference between the maximum value and the minimum value. In the process (161), the best axis-1-contrast change limit (STDMMSA) is compared with the difference between the maximum value and the minimum value (SA to TF^) calculated in the process 1151. change limit (ST
DM to SA) than the difference between the maximum and minimum values (SAMT
If F^) is larger, it is assumed that there is a coma defect in the on-axis contrast, and the corresponding beat/beat ('l'l) in the judgment register is determined.
4 bits [1] of DSO are set to 1. As a result, when the contents of the r1 constant register are transferred and stored in the display control memory, the LED 64B (A-COM) of the display section 6, which indicates the defect, is turned on. In the process [171, the best axial contrast trimming (S
TD to INA) and the average value calculated by treatment [+5] (HK
NMTFA). Here, the average value (H
If KNMTFA) is smaller, it is determined that the axis)-contrast is insufficient, and the corresponding focus of the r1 constant register (5 focus [1] of the determination register DSO) is set to 1. As a result, when the contents of the P1 constant lens are transferred and stored in the display control memory, the LED 64C (A-MTF-LOW) of the display section 6, which indicates the defect, is turned on. In process [18], the best axis] Nico/Trust trim (STDMINA) is compared with the minimum i p'i (MTF ANA) calculated in process 115]. Here, if the minimum value (MTFMINA) is smaller than the best axis (contrast trimming) (STDMINA), it is determined that a part of the contrast on the axis is insufficient, and the corresponding bit of the judgment register (the contrast trimming register DSO 6 bits N, I)
Let be 1. As a result, when the contents of the determination register L are transferred and stored in the display control memory, the display section 6 which is an indication of the defect in question
Turn on LED64D (A-MTF・PL). In processing [+9], from the four off-axis contrasts (MTFZ) at the off-axis image plane position measured at around 40,000, MTFMAXZ: maximum value MTFMINZ, minimum value HKNMTFZ: average value SAMTFZ: maximum value and minimum value Find the difference between. In the process [201, the best off-axis contrast limit (S
TDMINZ) and processing [191
i(HKNMTFZ). Here, if the average (I/i (HKNMTFZ) force) is smaller than the best off-axis contrast limit (STDMINZ), it is determined that the off-axis contrast is insufficient, and the corresponding bit of the judgment register (of the judgment register DSI) is determined to be insufficient. 3 bits 1-1) are set to 1. As a result, when the contents of the above 'r1 constant register are transferred and stored in the display control memory, LE065E (Z-MTF-LOW) of the display unit 6, which is an indication of the defect, is set to 1. In process [211, the best off-axis contrast change limit (STDMMSZ) is compared with the difference between the maximum value and the minimum value (SAMTFZ) calculated in process [191]. change limit) (STD
MMSZ ) than the difference between the maximum value 1 and the minimum value (SAM
TFZ) is larger, it is determined that the off-axis frame is defective, and the correspondence hint of the 'l'1 constant register (judgment register D
SL's 2 focus 11) is set to 1. This allows −[,
When the contents of the judgment register DSL are transferred and stored in the display control memory, the LED of the display unit 6 which is an indication of the defect concerned
Turn on 65D (Z-COM). In the process [221, the individual judgments in the judgment subroutine 51] (and then the overall judgment is carried out,
Check all the focuses of the r1 constant registers DSO and DSI. In other words, if the lens l to be tested has some kind of defect, the bits in either the determination register DSO or DSI should become 1 by executing each process up to the above process [21]. Therefore, by inspecting the states of all the bits of the 'locker transistors DSO and DSI, it is possible to know whether or not there is any defect in the lens l to be inspected. In other words, if all bits in the 1 judgment register DSO and []S+ are O, the lens to be tested l is judged to be good, and '
The r1 constant suffix subroutine 51I sets the 8-bit "1" of the judgment register OS+ to 1.As a result, the contents of the i++ constant register are transferred and stored in the display control memory, and a non-defective product is displayed. LE062B (good) of the display unit 6 is turned on.On the other hand, all bits of the determination registers DSO and DSI are checked, and if there is even one bit of l, the lens 1 to be tested is found to be defective.
Since there is some kind of defect corresponding to the bit, the lens 1 to be tested is determined to be defective, and the general defect determination corresponding register (determination register DSI) of the determination subroutine 51 is determined.
The 7th bit [1] of is set to 1. As a result, when the contents of the two-leg determination register DSI are transferred and stored in the display control memory, the LED 62A of the display unit 6, which indicates a defective product,
(Defective) lights up. Process [23]-c is r4 constant register DSO Oyohi DS
The contents of l are stored in the display control memory within the memory. That is, by executing the process 123J, each defect content that is a 1 determination result is stored in the display control memory, and the content is displayed by lighting on each LED of the display unit 6. This process is
This processing is performed for handling reasons, such as the fact that the determination registers DSO and DS1 are registers for arithmetic processing within the determination unit 5, and are also used in the determination 11 subroutine 52, which will be described later. The r1 constant subroutine 51 executes the processes described in Section 2-23 (1) below in the order of description. Next, the identification subroutine 52 will be explained. In this judgment subroutine 52, the above-mentioned contrast)
Judgment of the test lens l based on the contrast determined in step 311 in subroutine 44;
11 The lens to be tested l is identified based on the constant contrast. As the criterion here, the reference value prefixed with ST[] mentioned above in the r1 constant suffix subroutine 51 is used. FIG. 24 1/2 to 2/2 is a flowchart of the determination subroutine 52 shown in FIG. 16. The following describes the flow of each process (procedure) shown in the figure. Processing [In +1, fl', 8 or 12 axes in predetermined 8 or 12 directions with side redundancy at the I-axis on-image plane position'; From contrast, MTFMXLA:
Maximum value MTFMNLA: Minimum value) IKNMFLA: Average/average value SAMTFLA: Find the difference between the maximum value and the minimum value. In process [2], the change limit of the best axis contrast (STDMMSA) is compared with the difference between the maximum if and the minimum if calculated in process [1] (SAMTFLA). Here, if the difference between the maximum limit f and the minimum value (SAMTF^) is larger than the best axial contrast change limit (STDMMSA), it is determined that the axial contrast is undefined, and the PII constant register is The jε bit (3 bits of the fast star DSO) is set to 1. As a result, when the contents of the determination register are transferred and stored in the display control memory, the L of the display section 6, which indicates the defect, is
Turn on ED64A (A-ASU). In processing [3], the axial contrast limit at the image plane is applied to 11 Yusuke (NLA to STD), and processing [11
Compare with the fLJ value (HKNMFLA) calculated in . 1': Junsuke-1-axis at the image plane ↓-contrast limit (STDMNLA)
If NMFLA ) is smaller, it is determined that the on-axis contrast value is insufficient, and the corresponding bit in the determination register (bit 5 of determination register DSO, bit [I) is set to 1. As a result, when the contents of the 'l'1 constant register are transferred and stored in the display control memory, the LED 64C (A-MT
F LOW) lights up. process

[4] Then, the average axis is defined as the axis −l contrast limit at the image plane, ) (STDMNLA), and the processing [1
] and compare it with the minimum value (MTFMNLA) calculated by -1. 11 axial contrast limit at the image plane) (STDMNLA)
If MTFMNLA) is smaller, it is determined that a part of the on-axis contrast value is insufficient, and the corresponding bit in the determination register (6 hints + 1 in the determination register DSO) is set to 1. As a result, when the contents of the two-leg determination register are transferred and stored in the display control memory, the display section 6 which is an indication of the defect
Turn on LED64D (A-MTF-PL). Place Jul! [5] So, the measured value of off-axis contrast (
data) and execute the data backup. The eight or twelve off-axis contrast measurements are each stored in a dedicated save register (MTFZLO to MTFZL7 or MTFZLO to MTFZI, 11). Therefore, when off-axis contrast is measured for eight directions, the fourth direction's measurement 11'1, that is, the contents of the save register (MTFZL3), is changed to the eighth direction's! ! Transfer to the save register (MTFZL7). Thereafter, the measured value of the seventh direction, that is, the contents of the save register (MTFZL6), is transferred to the save register (TFZL3) of the fourth direction. The transfer of this measurement step 1 is carried out by the following process [5 in 61].
1 calculation process! This is a preparation for returning to Japan, and is a data saving operation since the measured value in the fourth direction is the data to be transferred to the personal computer unit PC, which will be described later. Also, 1
When the off-axis contrast is determined for two directions, all the measurement data is used, so the process directly proceeds to the next process [6] without performing the process [51]. In process 161, the off-axis contrast Jll constant (/i
From MTFMXLZ: Maximum value MTFMNLZ: Minimum value III) IKNMFLZ: ('Average value SAMTFLZ: Maximum value) Find the difference between the maximum value and the minimum value. In addition, when off-axis contrast is measured in 8 directions, save register (MTFZL 'O~MTFZL5
) from the contents of the above six values. Also, when off-axis contrast is measured in 12 directions, iJ! The above six values are obtained from the contents of the save registers (MTFZLO to MTFZL11). In process [73], the off-axis contrast 71111 planting that was evacuated in process [5] is restored. In other words, when off-axis contrast is measured in 8 directions, i! ! The measured value of the 4th direction saved in the save register (MTFZL7) is transferred to the original save register (MTFZL3) and returned to the original state.Now, the measured value of the 8th direction is transferred to the above process [
5], but this is not a problem because the measured value in the fourth direction, which is symmetrical to this, has been secured. In addition, the off-axis contrast for 12 directions is ΔII
If it is determined, there is no need to execute the process [7],
Immediately after executing process (61), proceed to the next process 181. In process [8], the off-axis contrast limit (STDMNLZ) on the qi-equal axis image plane and the minimum i+/i (MTFMNLZ) calculated in process [61] are calculated. Compare the minimum value (TFMNLZ to
) is smaller, the direction of the curvature of field should be inspected, as there may be a poor combination of field curvature and eccentricity. In addition, the off-axis contrast limit at the average axis-H image plane (SD
If the minimum value (MTFMNLZ) is not smaller than MNLZ), the process immediately proceeds to process [IO]. The direction of field curvature has already been checked by the rlI constant subroutine 51. In other words, (PPZGo) > (P
PZGU) then over one direction, (PpZGO) <
If (PPZGU), it is under one direction. Therefore, if the image plane of the test lens is curved in one direction, it is identified as an abnormal off-axis contrast due to the combination of under and eccentricity, and the corresponding bit in the determination register ('ill fixed';'7 .Event[]S1+7) 5 bit [1) is set to 1. As a result, when the contents of the determination register ``-'' are transferred and stored in the display control memory, the LED 65G (U+H) of the display section 6, which indicates the defect in question, is turned on. On the other hand, if the image plane of the test lens l is overly curved in one direction, it is determined that the off-axis contrast is abnormal due to the combination of overshoot and eccentricity, and the correspondence hint of the 't'l constant register (judgment register DSL) is determined. 6 bits L are set to 1.As a result, when the contents of the above-mentioned I adjustment register are transferred and stored in the display control memory, the LED 65H (o+H) of the display section 6, which indicates the defect, is lit.Processing 19], the average value of the off-axis contrast at the image plane is applied to the average axis, l-(ST[1MNH2), and the processing [
Compare with Kariyunsen (HKNMFLZ) calculated in 61. and the average axis], off-axis contrast at the image plane (7) 't' EJ value no 1, 1 mi, 7) (ST
IIMNH2) If the average value of twist (HKNMFLZ) is smaller, it is determined that the off-axis contrast value is insufficient, and
The corresponding bit of the judgment register (3 bits "1" of the judgment register DS1) is set to 1.As a result, when the contents of the judgment register are transferred and stored in the display 1 control memory,
LED65E (Z-
Light up MTF fist LOW). In processing [10I, the change limit of Qira off-axis contrast (ST[]MMSZ) and the maximum (calculated in processing [61]
The difference between di and the minimum value (SA to TFLZ) is compared. Here, the best off-axis contrast change limiter) (ST
DMMSZ) than the difference between the maximum value 1 and the minimum value (SAM
If TFLZ) is larger, it is determined that off-axis contrast variation is abnormal, and the corresponding hit in the determination register (4 bits 1 of determination register DSL) is set to 1. As a result, when the contents of the determination register are transferred and stored in the display control memory, the LED 65F of the display unit 6, which is an indication of the defect,
(Z-HEN) lights up. In process [11j, all bits of 2 judgment registers DSO and DSI are checked. This is the judgment subroutine 5.
Similar to the case of process 1 [22J], comprehensive judgment is performed based on the random judgment in 1 judgment subroutine 52, and all bits of each hit in judgment registers O5O and O3+ are checked. In other words, the register D
SO and [If all bits of lSI are O, test lens 1 is determined to be non-defective, and the register corresponding to the overall good quality of the 1 determination subroutine 52 (8 bits of determination register O5+)
1) is set to 1. As a result, when the contents of the two-leg determination register are transferred and stored in the display control memory, LE062B (good) of the display section 6, which indicates a non-defective product, is turned on. On the other hand, if all the bits in the determination registers DSO and [lSI are checked and even one bit is 1, it means that there is some kind of defect in the test lens 1 corresponding to the person in question. 1 is determined to be a defective product, the lens 1 to be tested is determined to be a defective product, and the 7th bit [1] of the general defective determination correspondence register ('rl constant register O3+) of the 1 determination subroutine 51 is set to 1. As a result, when the contents of the determination register are transferred and stored in the display control memory, the LED 62A (defective) of the display section 6, which indicates a defective product, is turned on. In process []21, the contents of the determination registers DSO and DSI are stored in the display control memory within the memory. That is, the processing

By executing [I2], each defect content as a result of the determination tk1i is stored in the display control memory, and the content is displayed by lighting on each LED of the display unit 6. This process is also similar to the process of the determination subroutine 51 described above [23J
Similarly, this process is based on handling reasons. The determination subroutine 52 executes the above 12 items of processing in the order in which they are described. "Display Unit 6" (Configuration) The display unit 6, as shown in Figure 25, displays the determination result by the determination unit 5 by lighting light emitting lights (LEDs) arranged on the display panel 61. . The display panel 61 has LEDs 62A and 62B for overall judgment.
and L for each judgment da1 corresponding to the judgment by the judgment unit 5.
ED (63A/63B-64A/648/64C/6
4D・65A-65Bφ65C・65D-65E・65
F-65G and 65H) are placed at predetermined positions as shown in Figure 26. Note that a power switch 66 for the lens tester LT, a measurement operation start switch, etc. are also arranged at -X within the display panel 61. (Function) Each LED arranged on the display panel 61 is blink-controlled by the display control memory provided in the microcomputer that constitutes the judgment section 5 together with the control section 4, as explained in the above-mentioned section of the judgment section 5. That is, the display control memory stores the contents of the aforementioned fl determination registers SO and DSI in which the determination result by the 1 determination unit 5 is stored when -. Each LED of the display panel 61 corresponds to the contents of the display control memory, that is, each bit of the determination register DSO and O3+ in the identification section 5, and corresponds to the state of each person (O or engineering). The configuration is such that blinking is controlled. In other words, each LED corresponds to the human state y! When 1 is O, the light is turned off, and when 1 is O, the light is turned on. The correspondence between each LED and each bit of the judgment register DSO and O5+, that is, which LED corresponds to the judgment register DSO
As to which bin of the DSL corresponds to this, it will be explained in each case in A1 of the explanation of the 1 determination subroutines 51 and 52, so it will not be repeated here. Next, specific display contents by each LED will be explained. When the lens 1 to be tested 62A is defective (i.e., it fails even one of the various standard standards), the LED 62A of the overall fJl constant 62B will always display one of the LEDs for each inspection item described later. (lit). 62B lights up when the lens l to be tested is good (when all various criteria are satisfied). Regarding the LEDs for each judgment item, 63A to 63B indicate mechanical pack focus defects, and 64A to 64D indicate defects in the lens axis or center. 65A to 65H indicate a defect outside the axis of the lens, that is, in the peripheral area, and when the light is lit, this indicates the defect. Hereinafter, the display (lighting) by the LED for each determination item LI will be explained individually. When the lens to be tested 1 clears all n constant criteria. 62B, which indicates a good product, lights up. If the product is defective, 62A will light up to indicate that it is a defective product.
The details (reasons) of the defect are displayed by lighting up different LEDs for determination 11 from 63A to 65H. 63A is a mechanical pack focus excessive defect (rb
(large) lights up. 63B is defective due to lack of 1 mechanical focus pack (rb
Lights up when (small). 64A lights up when there is a -11 upper ascent failure, that is, a failure due to an abnormal change in the axis-hibeak (A-ASU). Possible causes of this defect include eccentricity and poor polishing of the constituent lenses constituting the lens 1 to be tested. 64B lights up when there is an axis-comma failure, that is, a failure due to an abnormal change in the best on-axis contrast (A-COM). Possible causes of this defect include eccentricity and poor polishing of the constituent lenses constituting the lens 1 to be tested. 64C is defective due to lack of contrast on Ihh, that is, 4
i Equiaxial MTF image i is too small (A-MTFL
Lights up when O). A possible cause of this defect is poor polishing of the constituent lenses constituting the lens 1 to be tested. 64D is a defect in which part of axis 1-contrast is insufficient (
Lights up when A-MTFPL). This is by far the worst defect among the defects shown by 64G. Therefore,
When 64C lights up, 64D also lights up. 65A lights up when there is an under-defect, that is, a defect in which the off-axis image plane is too close to the lens side than the on-axis image plane (UN[l). The cause of this defect may be poor spacing or large eccentricity of the constituent lenses constituting the lens 1 to be tested. 65B lights up when there is an error (0VER) in which the off-axis image plane is farther from the lens side than the on-axis image plane. The cause of this defect may be poor spacing or large eccentricity of the lenses constituting the lens 1 to be inspected. 65C lights up when there is an off-axis unalignment defect, that is, a defect where the off-axis image plane is tilted (Z-ASU). A possible cause of this defect is eccentricity of the constituent lenses that make up the lens to be tested l. 65D lights up when there is an off-axis coma defect, that is, when there is an abnormal change in the best off-axis contrast (Z-CON). Possible causes of this defect include poor polishing and significant eccentricity of the constituent lenses constituting the lens 1 to be tested. 65E lights up when the off-axis contrast value is insufficient, that is, when the f-equal off-axis contrast value is too small (Z-MTFLO). Possible causes of this defect include decentering of the constituent lenses constituting the lens to be inspected 1, and alignment defects such as changes in machining interval. 65F lights up when there is a defect (Z-)IEN) in which the off-axis contrast fluctuates, that is, the off-axis contrast changes drastically. Lights up when H) is defective. A possible cause of this defect is poor alignment of the constituent lenses constituting the lens 1 to be tested. 65H lights up when a part of the off-axis contrast is small and there is an over-defective (0+)I). The cause of this defect is thought to be poor alignment of the constituent lenses that make up the lens 1 to be tested. By displaying the above defect judgment, it is possible to determine whether the lens to be tested is defective or to separate the cause of the defect, thereby increasing the efficiency and efficiency of the inspection work. be. [Systemization of Lens Tesque LT 1] In this embodiment, a lens tester system is constructed by connecting a personal computer (PC) to be described later to the lens tester LT as shown in Fig. 26, and information (measurement and judgment data) from the lens tester LT is configured. This makes it possible to process (Configuration) The personal computer section PC is a so-called personal computer, and has a computer 71. It is composed of a +- board 72, a CRT display 73, and a printer 74. The computer 71 of the personal computer IPc is a lens tester LT.
It is connected by a data bus DB to the microcomputer that constitutes the control unit 4 and determination unit 5 of the lens tester LT, and the measured values from the lens tester LT and commands from the personal computer unit (Function) Then, the personal computer!PC statistically processes the data input from the lens tester LT to create secondary data useful for defect countermeasures 9 quality control, etc. This data can also be printed out using the printer 74. The measurement data and secondary data can also be printed out on the CRT display 7.
3 and can be printed out using a printer 74. This allows the measurement data to be visualized, allowing for more detailed image surface conditions that cannot be seen from the judgment display on the display unit 6 of the Lens Test LT.
”. FIG. 27 is an example of a graphical display of measurement data on the CRT display 73. The graphical display shows four types of graphs (the graph on the left side of the screen is called G1. The graph on the bottom left of the screen is called G2. The graph on the top right of the screen is called 03, and the graph on the bottom right of the screen is called G4.) These are displayed simultaneously and clearly represent the characteristics of the lens l to be tested. The coordinates of each graph are graph Gl, the vertical axis of G2 is the contrast and image plane position, graph G3... G4's Mt4! IIf
represents the contest test, and the horizontal axis represents the direction for each graph.However, January on the horizontal axis is the graph Gl,
In G2, the four directions in the contrast degree measurement subroutine 43 are plotted in graph G3. G4 represents 8 or 12 directions in the contrast measurement subroutine 44. Next, each graph will be explained individually. Tara 7Gl shows the peak value of the axial contrast in each direction measured in the contrast measurement subroutine 43 and its image plane position (the second image plane position of the best axis), and the peak value of the contrast at each measurement point is shown as a solid line. The position (best image plane position) is shown by a dashed line. In addition, installation t1
The image plane position is also displayed, and the image plane condition 1 of the tested lens is shown.
This makes it easy to understand changes in g. Graph G2 shows the peak i of off-axis contrast in each direction measured in the contrast measurement subroutine 43 and its image plane position (best off-axis image plane position).
The peak peak of the contrast at each measurement point other than 1 is indicated by a solid line.
The position (best image plane position) is shown by a dashed line, and the designed image plane position is also shown as in the case of Tara 7G1. Graph G3 is a graph of the contrast on the axis for each direction at the average axial image plane position measured in the contrast measurement subroutine 44, and the contrast on the axis is shown as a solid line, and it also shows the contrast for the lens under test. The reference value for pass/fail judgment is shown by a chain line. Therefore, in the graph 3G, if the contrast shown by the solid line exceeds the standard value for quality determination, the lens is determined to be non-defective in terms of axial contrast. Graph G4 is a graph of the off-axis contrast for each direction at the average on-axis image plane position measured in the contrast measurement subroutine 44. The off-axis contrast is shown as a solid line, and it also indicates the quality of the lens to be tested. 'rJJ constant standard ((i is shown by a dashed line. Therefore, in the same way as in graph 3G, in graph 4G, if the contrast shown by the solid line exceeds the previous value for the basis of pass/fail judgment, the off-axis contrast It is determined that the lens is of good quality. From the above graph display, for example, it is possible to read the failure of the optical M of the tested lens and its cause as shown below. (1) Graph G2 When the graph of the off-axis image plane position of each measurement point intersects with the designed image plane position as shown in Fig. 28, the image plane is tilted as shown in Fig. 30(a). It can be seen that this has occurred.Such a state ynI occurs when the constituent lenses of the test lens l are decentered. (2) As shown in Fig. 29, in the graph Gl, the axis of each measurement point The graph of the image plane position above is based on the design image plane position, but in graph G2, the graph of the off-axis image plane position of each measurement point is shown on either the upper or lower side of the image plane position (Fig. In this case, the 30th
1; As shown in 4(b), it can be seen that the image plane is curved (in the figure, it is curved to the under side). In such a situation,
This occurs when there is a change in the machining intervals of the constituent lenses of the lens to be tested l. [Effects of the Invention] As explained above, according to the present invention, when a large number of contrasts are continuously obtained from the contrast measuring means, a predetermined number of contrasts are collected and their average value is used as true measurement data, and Each time the predetermined number of data are collected or the detection means is moved, the newly obtained contrast is shifted by a predetermined number in the direction in which the newly obtained contrast data is taken in at that step. Harassment is reduced and the data is rounded off to stable data. In other words, by using the above-mentioned so-called true measurement data, the judgment unit can accurately judge whether the lens to be tested is good or bad, and thereby the lens to be tested can be tested with high precision6.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of a lens tester to which a preferred embodiment of the data averaging method according to the present invention is applied, FIG. 2 is a plan view of the lens mount, and FIG. 3 is a cross section taken along III-III of the lens mount. Figure 4 is a configuration diagram of the light source section, and Figure 5 is a configuration diagram of the light source section.
The figure is a graph showing the radiation or transmission spectral characteristics of each component of the light source section, Figure 6 is the plane IA of the chart, Figure 7 is a plan view of a part of the off-axis mirror, Figure 8 is its left side view, Figure 9 is a plane view of the sensor section, Figure 1O is its x-xFli plane view, and Figure 1
Figure 1 is a cross-sectional view taken along line XI in Figure 9, Figure 12 is a block diagram of the arithmetic circuit, Figure 13 is an explanatory diagram of a sine wave signal related to contrast calculation in the arithmetic circuit, and Figures 14 and 15.
The figure shows the off-axis measurement point position, Figure 16 is a flowchart of the control unit and determination unit, Figure 17 is a characteristic curve of contrast value versus day focus amount obtained by measurement, and Figure 18 is a subroutine for contrast measurement. Flowchart, FIG. 19 is a conceptual diagram of the scanning average register group, FIG. 20 is a conceptual diagram explaining scanning time reduction, FIG. 21 is a flowchart of the determination subroutine, and 22L71 is a diagram showing the reference image plane position and the average image plane position. Explanatory diagram showing the relationship between
4 is a flowchart of the determination subroutine, FIG. 25 is a plan view of the display panel, FIG. 26 is a configuration block IA of a lens tester system to which the lens tester LT according to the present invention is applied, and FIG. 27 is a diagram of measurement results by the personal computer section. A diagram showing an example of the display, FIGS. 28 and 29 are explanatory diagrams of the display of FIG. 27, FIG. 30 is an explanatory diagram of the image plane change corresponding to FIGS. 28 and 29, and FIG. FIG. 3 is an explanatory diagram of an example projection test. l...Test lens CA, CZ...Chart (lattice chart) 31A/3
1Z...CCD sensor (detection means) 3...Contrast measurement means LT-...Lens tester Figure (+/1) (a) (%) (b) Wavelength (nm) (C) (l/ l) Wavelength (nm) Wavelength (r+m) 400 6CX) 800 Wave 5 (nm) +00 Figure Figure Direction Figure Direction Figure - L Continuation Supplement (Method) 4￥Fraud Agency Commissioner Fumiki Yoshida Display of the case No. 1988 Patent Application No. 215978 Name of the invention Lens tester data averaging Relationship to the person who corrects the processing method Patent applicant (052) Asahi Optical Industry Co., Ltd.

Claims (1)

[Claims] A chart image of a lattice chart formed by a lens to be tested is detected by a detection means that can be moved in steps in the optical axis direction of the lens to be tested, and a contrast measuring means that operates in conjunction with the step movement of the detection means detects the chart image of the lattice chart. In a lens tester that continuously obtains a large number of image contrasts based on a chart image detection result by the detection means,
When a large number of contrasts are continuously obtained from the contrast measuring means, a predetermined number of contrasts are collected, an average value is calculated, and this is used as true measurement data, and the predetermined number of contrasts are collected at every movement step of the detection means. A data averaging processing method for a lens tester, characterized in that the contrast newly obtained in that step is shifted by a predetermined number in a direction to incorporate the contrast.