JPH01135261A - Film image reading device - Google Patents

Abstract

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

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a film image reading device, and particularly to a film image reading device that reads a film image by irradiating a light image transmitted through a microfilm onto a photoelectric conversion element. The present invention relates to an image reading device.

<Prior art> Conventionally, various types of information such as documents generated in large quantities are recorded at high density on microfilm, and the recorded images on the microfilm are enlarged and projected to a predetermined size each time as necessary.
Alternatively, various film image reading and reproducing apparatuses have been proposed, such as enlarger printers and reader printers, which read the image with an image sensor and reproduce it by printing out the image. In such devices, images recorded on microfilm are enlarged and projected onto a display unit such as a screen for observation, or the displayed image is monitored by an operator and then printed on the display unit. according to the copy size mark indicating the image area that has been
The display image is recorded on recording paper of a predetermined size.

For example, in the apparatus described in Japanese Unexamined Patent Publication No. 62-16664, as shown in FIG. After passing through the imaging lens 5, the light flux that has passed through the film image 2 is reflected by the movable mirror 6, and further passes through the magnifying lens 7 and is irradiated onto the screen 8. As a result, an enlarged image 9 is projected onto the screen 8.

On the other hand, when printing out film image 2,
The movable mirror 6 is rotated to the position shown by the broken line, and the light beam that has passed through the film image 2 is reflected by the fixed mirror 11, and the optical image of the film image 2 is magnified by, for example, 2.78 times to form an image sensor. Photoelectric conversion device (COD)
12.

This photoelectric conversion element 12 is mounted on a carriage 15 that is provided to be movable back and forth with respect to guide rails 13° 14, and is moved at a predetermined speed by drive wires 16° 17 to perform reading in the sub-scanning direction. It is now possible to Further, reading in the main scanning direction is performed simultaneously by a pixel column consisting of a large number of minute pixels.

As the photoelectric conversion element 12, one with a high pixel density is generally used. For example, a 7 μm pixel is
A structure in which the pixels are arranged in rows in the main scanning direction is employed. In this case, the effective pixel column length SP is 35InI
It becomes n.

However, in such conventional devices, the size of the film image to be read is limited due to the size of the photoelectric conversion element 12, and if the image is large and extends beyond the photoelectric conversion element 12, the necessary This means that reading functions cannot be performed. For example, the readable projected image on the photoelectric conversion element 12 for 16 m film as described above has dimensions of at least 35 tones or less on the light receiving surface of the photoelectric conversion element 12, and the image fineness is 71 lines. /#(1
/7μm×2) or less. On the other hand, 35s
For width microfilms, the standard (J l5Z6
004), the maximum dimension of the film image size is approximately 2
8#l#lX39.6#, and the fineness of the image resolution is a maximum of 135 lines/m.

Therefore, the image on 35IIR microfilm is
When reading with a single photoelectric conversion element, it is almost impossible to enlarge the size of the image in order to prevent the image from protruding from the photoelectric conversion element. On the other hand, to increase image resolution, the maximum image resolution cuff 1
Maximum resolution of 13 for a photoelectric conversion element with 1/M
This means that it is necessary to enlarge the film image of 5 lines/m approximately twice and project it. As described above, in the conventional apparatus in which one photoelectric conversion element is provided corresponding to one projection lens to perform a reading operation, there is a problem that large film images cannot be read properly.

Furthermore, in conventional reading devices, the photoelectric conversion element is moved to perform sub-scanning reading. However, in such a scanning system, since the sub-scanning movement must be performed over the image width of the enlarged image, the amount of movement becomes large, and a drive system that reciprocates the photoelectric conversion element at high speed is required. This has no choice but to increase costs.

Furthermore, if the amount of sub-scanning movement is large, the angle of view of the light beam irradiated from the projection lens to the photoelectric conversion element becomes large, for example, to a half angle of view of 20 to 22 degrees. While the magnified projection image is moved from one end to the other end, the image illuminance changes significantly, for example, by about 20%, due to the so-called COS θ law, the light focusing characteristics of the focusing lens, etc. For this reason, the conventional device has the problem of having to perform complicated light amount correction (shading). Furthermore, since the half angle of view of the condenser lens is large, there arises the problem that the resolution of the enlarged image in the end region in the sub-scanning direction is reduced.

<Purpose> Therefore, an object of the present invention is to provide a film image reading device that can read images properly and efficiently even on large-sized films.

(Structure) In order to achieve the above object, the first invention provides a film image reading device that reads a film image by projecting an optical image obtained by transmitting a film onto a photoelectric conversion element. A plurality of photoelectric conversion elements are arranged in parallel in the main scanning direction in the light receiving plane so as to split the transmitted light from the film into a plurality of light beams and receive the light, and each of these photoelectric conversion elements It has a configuration in which the columns extend in the main scanning direction and are arranged so as to have light receiving areas that overlap each other in the main scanning direction.

In an apparatus having such a configuration, the light transmitted through the film is divided into a plurality of photoelectric conversion elements and is separately irradiated and received by each of the photoelectric conversion elements, thereby reading an image.

Further, the second invention provides a film image reading device that reads a film image by projecting an optical image of the film image onto a photoelectric conversion element using a predetermined optical system, wherein the photoelectric conversion element A plurality of photoelectric conversion elements are arranged in parallel in the main scanning direction within the light receiving plane so that the transmitted light is divided into a plurality of light beams and received. exists, and
It is equipped with light receiving areas that overlap each other in the main scanning direction,
The optical system is configured to be scanned and moved in the sub-scanning direction of the film image.

In a device with such a configuration, the light transmitted through the film is divided into multiple photoelectric conversion elements, each of which is irradiated and received separately, and the image is read, and the optical system is moved. Reading scanning is performed in the sub-scanning direction.

Embodiments of the present invention will be described in detail below with reference to the drawings.

First, a film image reading and reproducing apparatus to which the present invention is applied includes a main body part on which a microfilm to be read is mounted and irradiated with light, a display part installed on the upper side of this main body part, and a display part installed on the upper side of this main body part. It consists of a laser printer installed at the bottom.

The main body section is provided with a reading device as shown in FIG. In this reading device, the microfilm 21 is attached to and held by an aperture card 22, and the front side portion of the microfilm 21 (
(left side part in Fig. 1) includes a light source 23 and a condensing lens 2.
A lighting unit 25 having 4 is arranged. Also,
An imaging lens 26 is disposed in the back part of the microfilm 21 (the right part in FIG. 2). and,
The illumination unit 25 and the imaging lens 26 are integrally mounted on a support stand (not shown), and the optical systems are arranged so that their optical axes coincide. The imaging lens 26 has a 2.38x magnification function.

Further, a film holder (not shown) that holds the aperture card 22 is engaged with and attached to a groove rail, and is slidable in the sub-scanning direction, which is the image width direction of the microfilm 21, and in the vertical direction. That is, it is attached so as to be slidable in the main scanning direction. Then, the film holder is adjusted to move in the left-right direction by rotating the left-right positioning knob, and the film holder is adjusted to move up and down by rotating the vertical positioning knob, and the position of the microfilm 21 is adjusted. It is now possible to By making it possible to adjust the position of the microfilm 21 in this way, the position can be easily adjusted when displaying or copying images.
Misalignment during display/copying can be corrected.

Further, the illumination unit 25 having the light source 23 and the condensing lens 24 and the support stand holding the imaging lens 26 are moved a predetermined amount in the sub-scanning direction, which is the image width direction of the microfilm 21, by a feeding device (not shown). It is configured to be sent one by one.

On the back side of the imaging lens 26, a movable mirror (not shown) is swung to reflect the light beam emitted from the imaging lens 26 upward or to allow it to pass through without being blocked. It is set in. Further behind the movable mirror, a photoelectric conversion element 27 for reading the optical projection image emitted from the imaging lens 26 is installed, and above the movable mirror, the imaging lens 26 is installed. A display device is installed for projecting and displaying a light projection image emitted from the.

The photoelectric conversion element 27 is configured by arranging two elements in parallel, and each photoelectric conversion element 27 divides the transmitted light from the microfilm 21 into two beams of light and receives the light. . That is, both photoelectric conversion elements 2
7.27 are arranged in parallel and close to each other so that their pixel rows 27a, 27a extend in the main scanning direction (up and down direction) within the light receiving plane surrounded by the broken line, and both are arranged in parallel so as to be shifted by a predetermined amount from each other in the main scanning direction.

Each of these photoelectric conversion elements 27.27 is arranged so as to have light receiving areas that overlap with each other in the main scanning direction.

In a state where the approximate center of the entire image area I of the microfilm 21 intersects with the optical axis of the imaging lens 26, the image area 11 of the image area of the microfilm 21 above the lens optical axis and this The image areas that are enlarged and projected toward the photoelectric conversion element 27 of the image area IP1 extending from the image area ■1 to the lower side of the lens optical axis are Ilm, ■, and 11Tl, respectively, and the sum of these two image areas is For (11Ill+I, 11Il),
The effective pixel column lengths SP of the photoelectric conversion elements 27 are set to be equal. Further, the image of the microfilm 21 is enlarged and projected from the image area 2 below the lens optical axis and the image area I2 toward the photoelectric conversion element 27 in the image area IP2 extending above the lens optical axis. The image areas are 12 m and IP2 m, respectively, and are set so that the sum of these two image areas (■2□+I, 2 m) is equal to the effective pixel column length SPM of the photoelectric conversion element 27. .

As a result, the entire image area I in the width direction of the image area of the microfilm 21, that is, in the main scanning direction, is enlarged and projected without protruding outside the perforated pixel row length S'P of the photoelectric conversion element 27. , microfilm 2
The area IPm (1, P = I, 10 IP2) extending above and below the photoelectric conversion element 27 overlaps with the image area I P (1, P = I, + IP2) centering on the lens optical axis of the image area 1.
The image is projected as an enlarged image. Therefore, reading of the microfilm image by the photoelectric conversion element 27 in the pixel column direction, that is, in the main scanning direction, is carried out without any image loss.

Images on 35M microfilm intended for industrial drawings are created in accordance with the following JIS standard reduction ratio corresponding to the size of the drawing manuscript.

A commonly used photoelectric conversion element (7 μm x 7 μm, 50
The relationship between the image and the photoelectric conversion element when reading with 00 pixels) will be explained. The image dimensions in the width direction of the microfilm are:
The maximum size is 28 #I, and when projecting it onto a photoelectric conversion element by magnifying it 2.38 times and reading approximately 1/2 of the length with each photoelectric conversion element, first each photoelectric conversion element is The size of the enlarged image on the conversion element is 33.32■ (-28
/2x2.38), which is 4 if converted to the number of pixels.
This results in 760 (=33.32/7 μm) dots. On the other hand, the maximum size (Ao) of the corresponding drawing manuscript is about 420M (=841/2), so the reading density is about 11 dots (5.5 lines/m - 4760/420
), and similarly, from the dimensions of the drawing manuscript corresponding to each reduction ratio, the reading density is 16 dots (8 dots/
#), 22 dots (11 dots/
m). This is the fineness of the drawing manuscript that corresponds to the fineness of the film image shown in the table above, that is, A is 4.5.
Book/H1A1, 5.0 books 1Irm, A2, A3, A
4, exceeding the value of 7.1 lines/mm, it is possible to read extremely high-density images by using the microfilm image reading device according to the present invention. It is possible to obtain images.

Further, the reading device in this embodiment is equipped with a sub-scanning means as shown in FIG. As mentioned above,
Two of the photoelectric conversion elements 27 are arranged in parallel in a light receiving plane so that the transmitted light from the film is divided into a plurality of light beams and received, and an optical element is used to project a film image onto these photoelectric conversion elements 27. A system, that is, an illumination unit 25 having a light source 23 and a condensing lens 24, and an imaging lens 26 are integrally mounted on a support stand (not shown), and an optical system consisting of these is used to perform sub-scanning of a film image. It is configured to be integrally scanned in the direction.

In such an embodiment, when the film image of the microfilm 21 is enlarged and displayed on the screen, the film image of the microfilm 21 held on the aperture card 22 is illuminated by the illumination unit 25, and the film image of the microfilm 21 is illuminated by the illumination unit 25. After the transmitted light is magnified by the imaging lens 26, it is reflected by a movable mirror and changed upward, and then passes through a magnifying lens selected to have a predetermined magnification, is magnified to a required magnification, and is enlarged and projected onto a screen. . The enlarged image of the microfilm 21 projected onto the screen is focused by rotating the focusing knob, and the film holder is adjusted by rotating the left/right positioning knob and the vertical positioning knob. The position of the projected image is adjusted by adjusting the movement in the left and right and up and down directions respectively.

To obtain a copy of the enlarged projected image on the screen, first align the image position with the frame line and size display symbol printed on the screen, operate the selection switch to select the desired paper, and adjust the image density using the adjustment knob. After adjusting the number of copies and setting the number of copies by key operation, the start switch is turned on to start the copying operation.

By this operation, the movable mirror is swung, and the opening of the display device is closed by the movable mirror. As a result, external light is prevented from entering into the main body from the screen side, and at the same time, the film-transmitted light passes through the portion directly below the movable mirror and is received by the photoelectric conversion element 27 side.

The scanning procedure of the microfilm 21 in this case will be described below.

First, the light emitted from the light source 23 passes through the condensing lens 24, passes through the image area of the microfilm 21, and then passes through the imaging lens 26, directly below the movable mirror rotated as described above. The light passes through and is received by the photoelectric conversion element 27. At this time, each photoelectric conversion element 27.27 receives approximately half of the total projected image, and at the same time, it is possible to perform sufficient enlargement in terms of size, and at the same time, the two photoelectric conversion elements 27. Since the conversion elements 27 and 27 receive light in a state where they overlap each other in the main scanning direction, no omission occurs in the read image.

Furthermore, if the enlarged image of the film image is divided into two photoelectric conversion elements 27, 27 and read, the transfer of the signal charges accumulated in the photoelectric conversion elements by the shift register will be performed at both optical haze levels. The detection elements 27 and 27 perform the same operation in parallel, so that the transfer time can be shortened and the transfer frequency can be kept low compared to the case where the projected image is read by one photoelectric conversion element. That is, simply increasing the pixel column length of the photoelectric conversion element cannot be used because the transfer frequency will also be increased proportionally. Furthermore, as in this embodiment, if multiple photoelectric conversion elements are installed corresponding to a single projection lens, the focal length and brightness can be improved compared to the case where a single photoelectric conversion element is used. As a result, there are very few occurrences of overlaps, omissions, or non-uniform images in the copied images.

Sub-scanning is 1. As shown in FIG. 2, this is carried out by integrally moving the light source 23, condensing lens 24, and imaging lens 26 in a direction perpendicular to the optical axis indicated by the arrow. This scanning movement operation is performed by rotational driving of a pulse motor. At the start of scanning, the control circuit receives a signal from the laser printer's registration sensor that detects the leading edge of the roll paper, and based on this signal, the scanning pulse motor rotates in accordance with the selected copy size signal. Can be launched up to a number. As a result, the support base is moved so that the imaging lens 26 is positioned from the reference position indicated by C in FIG. 2 to the run-up start position indicated by S. When the optical axis of the imaging lens 26 reaches the scanning start position S, the position signal is emitted as a pulse count applied to the pulse motor, and a reading operation by the photoelectric conversion elements 27 and 27 is started.

While the number of applied pulses corresponding to the selected copy size is applied to the pulse motor, the imaging lens 26 is moved at a predetermined speed from the position indicated by the symbol S, through the position indicated by the symbol C, and to the position indicated by the symbol E; The sub-scanning movement is then completed. Further, as the imaging lens 26 moves, the light source 23 and the condensing lens 24 are also moved in the same way. In this case, the reading scanning speed is controlled based on the copy size and the magnification of the imaging lens 26, as described below. After the sub-scanning is completed, the pulse motor is driven to rotate in the opposite direction, and the support base, that is, the light source 23, the condensing lens 24, and the imaging lens 26 are returned to their reference positions. The movable mirror is returned to its original position by a signal generated when the support base is returned to its reference position, and the film image is returned to the state where it is enlarged and projected onto the screen.

Here, the distance by which the imaging lens 26 is moved for sub-scanning is determined by an amount corresponding to the projection magnification m of the imaging lens 26 and the selected copy size, and by a scanning movement speed corresponding to the copying magnification described later. This is the amount plus the run-up distance to reach the target. The moving distance SL for sub-scanning is I, which is the length of the microfilm image in the sub-scanning direction. , the magnification rate of the enlarged projected image is m (=b/a), and the pitch between both pixel columns of the two photoelectric conversion elements 27.27 is SD, then from these proportional relationships, SL=(mIo+SD)/(1+m ). This SL is I. smaller than

Incidentally, in the case of the generally used photoelectric conversion element TC106C, the SD is required to be 10M or more.

On the other hand, as shown in FIG. 3, when sub-scanning is performed by moving the photoelectric conversion element 27 side (conventional case), the movement distance SS required for scanning is equal to the width dimension ■ of the projected image. m
is equal to (Iom+SD), which is the sum of SD and the pitch between both pixel columns of the two photoelectric conversion elements 27 and 27. This SS is ■. It is considerably larger than the above-mentioned SL. That is, it is expressed as SL<1°<ss. By moving the imaging lens 26 to perform sub-scanning in this way, the moving distance required for sub-scanning can be made extremely small.

In addition, the so-called half-field angle θ when reading and scanning an enlarged image is only about 5.5 degrees, which is also much smaller than when sub-scanning is performed by moving the photoelectric conversion element. It will be done. Furthermore, since the optical axis of the condensed illumination and the optical axis of the imaging lens are always moved coaxially, the illuminance change of the enlarged image during scanning is about 2%, and a decrease in the resolution of the enlarged image is hardly noticeable. I can't. As a result, it is no longer necessary to perform light amount correction (shading) corresponding to scanning movement as in the prior art.

Furthermore, there is also a conventional sub-scanning reading method in which the microfilm side is moved. However, the scanning movement distance SF of the microfilm in this case is expressed as SF= (Iom÷SD)/m, and the scanning movement distance SL according to the present invention is expressed as follows:
mIo+SD)/(1+, m), SL<
SF, and it can be seen that the scanning method according to the present invention is superior to this scanning method as well.

As described above, the scanning method according to the present invention can shorten the scanning movement distance compared to any conventionally employed scanning method, and by arranging two photoelectric conversion elements 27, 27 in parallel. Even if the two pixel columns are separated by 10M or more, no adverse effects will occur.

A film image created at a scale that corresponds to the original size of the image is projected onto a screen at an enlargement magnification that corresponds to the scale, and a copy size is selected that corresponds to the size of this projected image. When designated by the selection switch, the sub-scanning movement range and sub-scanning movement speed are automatically set according to the selected size signal.

Main scanning control is performed by electrically processing an output signal from a photoelectric conversion element, which will be described later. The variable magnification control at this time is automatically performed in accordance with the enlargement magnification signal of the projected image. In this way, by automatically controlling the sub-scanning and main scanning, the required enlarged copy of the microfilm image can be easily and efficiently obtained without missing images or inappropriately reduced images. .

Note that, as in this embodiment, it is advantageous if the microfilm 21 is placed in a stationary state during the image reading sub-scanning, since it is possible to prevent the positional shift of the image during reading. Furthermore, when projecting an image onto a screen, the projected image can be positioned by moving the film holder that holds the microfilm 21 vertically and horizontally.

Next, a copy image is created by a laser printer based on the film image signals read by the photoelectric conversion elements 27, 27.

That is, first, in the writing section, laser light emitted from a semiconductor laser as a light source is modulated based on an input image signal, then formed into a predetermined beam diameter by a beam expander, and then reflected by a polygon mirror. The spot light is irradiated onto the photoreceptor drum through an fθ lens. By exposing and scanning the spot light, an enlarged latent image of the film image is formed on the photoreceptor drum.

At this time, the write scan is controlled in synchronization with the read scan by a detection signal from the beam detector. After the enlarged latent image is visualized by a developing device, this developed image is transferred onto recording paper of a predetermined size by a transfer device. The transfer operation is synchronized with the paper feeding operation based on a signal from the lens sensor. Further, the recording paper is selected from roll papers of different sizes based on the operation of a copy selection switch, and is cut into a predetermined length by a cutter provided in the paper feed path. The timing of this cutting is controlled based on a signal from a paper sensor. After the transfer, the recording paper is sent to a fixing device that fixes the developer, and is discharged from a tray provided at an exit portion of the fixing device.

(Effects) As described above, the film image reading device according to the first invention has a plurality of photoelectric conversion elements arranged in parallel, and receives the light transmitted from the film by dividing it into a plurality of light beams. Therefore, even a large film can be sufficiently enlarged, and the transfer time can be shortened compared to when a projected image is read by a single photoelectric conversion element, and the transfer frequency can be kept low. Compared to the case where a single photoelectric conversion element is used, variations in focal length and brightness can be reduced, and overlaps, omissions, and image non-uniformity in copied images can be effectively prevented.

Further, the film image reading device according to the second aspect of the present invention is configured such that the optical system for the plurality of photoelectric conversion elements arranged in parallel is moved in the sub-scanning direction of the film image. The scanning movement distance can be shortened for either scanning method, and even if the pixel columns of both are separated by a certain distance by arranging multiple photoelectric conversion elements in parallel, there will be no adverse effects due to this. You can prevent it from happening. Furthermore, it is possible to suppress the so-called half-field angle θ and illuminance changes when reading and scanning an enlarged image to be much smaller than before, as well as eliminate the reduction in resolution of enlarged images, and reduce the amount of light corresponding to the conventional scanning movement. Correction (shading) can be made unnecessary.

[Brief explanation of the drawing]

FIG. 1 is an explanatory perspective view showing the configuration of a film image reading device according to an embodiment of the present invention, FIG. 2 is an explanatory plan view showing the sub-scanning movement state of the reading device shown in FIG. 1, and FIG.
FIG. 4 is an explanatory plan view showing a sub-scanning movement state of a conventional reading device, and FIG. 4 is a schematic perspective view showing an example of a conventional film image reading and reproducing device. 21...Microfilm, 23...Light source, 24.
...Condensing lens, 26...Imaging lens, 27.27.
...Photoelectric conversion element.

Claims (1)

[Claims] 1. In a film image reading device that reads a film image by projecting a light image obtained by transmitting a film onto a photoelectric conversion element, the photoelectric conversion element A plurality of photoelectric conversion elements are arranged in parallel in the main scanning direction within the light receiving plane so that the light is divided into a plurality of beams and received. What is claimed is: 1. A film image reading device characterized in that the film image reading device is arranged so as to have light receiving areas that overlap each other in the main scanning direction. 2. In a film image reading device that reads a film image by projecting an optical image of the film image onto a photoelectric conversion element using a predetermined optical system, the photoelectric conversion element converts transmitted light from the film into multiple A plurality of photoelectric conversion elements are arranged in parallel in the main scanning direction within the light receiving plane so as to receive light divided into light beams, and each of these photoelectric conversion elements has its pixel row extending in the main scanning direction and 1. A film image reading device comprising light-receiving areas that overlap each other in the scanning direction, and wherein the optical system is configured to be scanned and moved in the sub-scanning direction of the film image.