JPH0636321A - Pickup inspection device - Google Patents

Abstract

(57) [Abstract] [Purpose] In the tilt adjustment of the objective lens actuator in the assembly process of the optical pickup, the spot inspection process can be automatically performed to reduce the burden on the operator and prevent the quality from varying. . When the number of peaks of a primary ring existing in two regions on an image sensor divided by a straight line L passing through a point P (xp, yp) is a and b, respectively, a value (a
-B) or a value (a / b) and a predetermined value H are compared with each other, and a means for comparing the magnitudes is provided to detect an abnormal spot based on whether or not there is an imbalance in the number of peaks. [Effect] An abnormal spot can be accurately detected by a simple calculation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spot inspection apparatus for an optical pickup used for adjusting an inclination of an objective lens actuator in an optical pickup assembling process, and more particularly, to a spot inspection process which can be performed automatically. The present invention relates to a spot inspection device for an optical pickup that reduces the burden on the operator and prevents the quality from varying.

[0002]

2. Description of the Related Art In the process of assembling an optical pickup, it is necessary to adjust the inclination of an objective lens actuator. Conventionally, as a method of adjusting the tilt of the objective lens actuator, a microscope, a camera, and a monitor are used, and instead of an optical disc, a cover glass having the same thickness is installed in parallel with the reference plane, and the spot of the objective lens is adjusted. An optical head adjusting method of enlarging and observing with a microscope is used (Japanese Patent Laid-Open No. 63-253538).

FIG. 16 is a diagram showing an example of a main part configuration of a conventional adjusting device for performing an optical head adjusting step. In the figure, 1 is a housing of an optical pickup, 2
Is a deflection prism, 3 is an actuator, 4 is a screw, 5 is an objective lens, 6 is a cover glass, 7 is a microscope, 8 is a camera controller, 9 is a TV monitor, and LB is a laser beam.

As shown in FIG. 16, a deflection prism 2 is provided in a housing 1 of an optical pickup. Further, an actuator 3 is provided above the housing 1, and an objective lens 5 is provided therein.

The actuator 3 is fixed to the housing 1 with a screw 4, but the inclination of the actuator 3 can be adjusted by adjusting the tightening method of the screw 4. A cover glass 6 having the same thickness as that of the optical disc is installed above the actuator 3 in parallel with the housing 1 of the optical pickup.

The conventional process of adjusting the tilt of the objective lens actuator is performed as follows. The laser beam LB is incident on the deflection prism 2, and the spot formed by the objective lens 5 is observed by the microscope 7. A camera (not shown) is connected to the microscope 7, and spots are displayed on the screen of the TV monitor 9 through the camera controller 8.

The operator adjusts the inclination of the actuator 3 while observing the display of the spot so that the primary side lobes are symmetrical. The tilt of the objective lens actuator is adjusted by the steps described above.

This adjusting step is performed for the purpose of improving the spot shape by adjusting the inclination of the objective lens incorporated in the actuator in parallel with the optical disc. Therefore, as described with reference to FIG. 16, the spot image is observed on the TV monitor, but this step is a step of improving the spot shape and simultaneously removing the spot having an abnormal shape (in other words, In many cases, it also serves as the step of inspecting the spot shape).

This spot inspection process is usually performed visually by an operator using an empirical allowable limit sample. Therefore, not only is the burden on the operator heavy, but the subjectivity is likely to occur, which causes a problem in that the quality varies.

[0010]

SUMMARY OF THE INVENTION According to the present invention, such inconvenience that occurs during the spot inspection of the conventional optical information recording / reproducing apparatus is solved, and the spot inspection process can be automatically performed, so that the burden on the operator is reduced. It is an object of the present invention to provide a pickup inspection device that reduces the fluctuations and prevents the quality variation.

[0011]

According to the present invention, firstly,
In a pickup inspection device that forms an image of light emitted from a lens on an image pickup element and performs arithmetic processing using the intensity I (x, y) at a point (x, y) on the element, the intensity is used as a processing means. The point P (x where I (x, y) is a peak
p, yp), a means for obtaining an intensity distribution I (x, y) on a plurality of straight lines passing through the point P (xp, yp) and on the image sensor, and each intensity distribution. A means for detecting the peak of the primary ring at I (x, y) and a peak of the primary ring existing in two regions on the image sensor divided by the straight line L passing through the point P (xp, yp). When the numbers are a and b, respectively, the value (a
-B) or a value (a / b) and a means for comparing the magnitude of a predetermined value H with each other.

Second, the light emitted from the lens is imaged on the image pickup device, and the intensity I at the point (x, y) on the device is measured.
In a pickup inspection apparatus that performs arithmetic processing using (x, y), as processing means, means for obtaining a point P (xp, yp) at which the intensity I (x, y) reaches a peak, and the point P (xp) , Yp) and means for obtaining an intensity distribution I (x, y) on a plurality of straight lines on the image sensor, and detecting a peak of a primary ring in each intensity distribution I (x, y). Means, a means for setting a plurality of straight lines L (L1, L2, ..., Ln) passing through the point P (xp, yp), and two regions on the image sensor divided by the respective straight lines Li. Means for comparing the value (ai-bi) or the value (ai / bi) with a predetermined value H for each Li when the number of peaks of the primary ring existing in is respectively ai and bi , And are provided.

Thirdly, the light emitted from the lens is imaged on the image pickup device, and the intensity I at the point (x, y) on the device is measured.
In a pickup inspection apparatus that performs arithmetic processing using (x, y), as processing means, means for obtaining a point P (xp, yp) at which the intensity I (x, y) reaches a peak, and the point P (xp) , Yp) and means for obtaining an intensity distribution I (x, y) on a plurality of straight lines on the image sensor, and detecting a peak of a primary ring in each intensity distribution I (x, y). Means, a means for setting a plurality of straight lines L (L1, L2, ..., Ln) passing through the point P (xp, yp), and two regions on the image sensor divided by the respective straight lines Li. When the number of peaks of the primary ring existing in is respectively ai and bi,

[Equation 3] And a means for comparing the magnitude with a predetermined value H.

Fourthly, the light emitted from the lens is imaged on the image pickup device, and the intensity I at the point (x, y) on the device is formed.
In a pickup inspection apparatus that performs arithmetic processing using (x, y), as processing means, means for obtaining a point P (xp, yp) at which the intensity I (x, y) reaches a peak, and the point P (xp) , Yp) and means for obtaining an intensity distribution I (x, y) on a plurality of straight lines on the image sensor, and detecting a peak of a primary ring in each intensity distribution I (x, y). And the number of peaks of the primary ring existing in the four regions on the image pickup device divided by the two straight lines intersecting at the point P (xp, yp) by a,
If b, c, d, then the value {(a + c)-(b + d)}
Alternatively, the configuration includes a value {(a + c) / (b + d)} and a means for comparing the magnitude of a predetermined value H.

Fifth, the light emitted from the lens is imaged on the image pickup device, and the intensity I at the point (x, y) on the device is measured.
In a pickup inspection apparatus that performs arithmetic processing using (x, y), as processing means, means for obtaining a point P (xp, yp) at which the intensity I (x, y) reaches a peak, and the point P (xp) , Yp) and means for obtaining an intensity distribution I (x, y) on a plurality of straight lines on the image sensor, and detecting a peak of a primary ring in each intensity distribution I (x, y). Means and a plurality of sets (M1, M2, ..., M) of two straight lines that intersect at the point P (xp, yp).
n) When the number of peaks of the primary ring existing in the four regions on the image pickup device divided by the respective straight lines Mi is set to ai, bi, ci, di in the counterclockwise direction, each Mi is set. With respect to the value {(ai + ci)-(bi +
di)} or value {(ai + ci) / (bi + di)}
And a means for comparing the magnitude with a predetermined value H.

Sixth, the light emitted from the lens is imaged on the image pickup device, and the intensity I at the point (x, y) on the device is formed.
In a pickup inspection apparatus that performs arithmetic processing using (x, y), as processing means, means for obtaining a point P (xp, yp) at which the intensity I (x, y) reaches a peak, and the point P (xp) , Yp) and means for obtaining an intensity distribution I (x, y) on a plurality of straight lines on the image sensor, and detecting a peak of a primary ring in each intensity distribution I (x, y). Means and a plurality of sets (M1, M2, ..., M) of two straight lines that intersect at the point P (xp, yp).
n) means for setting and the number of peaks of the primary ring existing in the four regions on the image pickup device divided by the respective sets of the two straight lines Mi to the left, ai, bi, ci, di
When

[Equation 4] And a means for comparing the magnitude with a predetermined value H.

Seventh, the light emitted from the lens is imaged on the image pickup device, and the intensity I at the point (x, y) on the device is measured.
In a pickup inspection apparatus that performs arithmetic processing using (x, y), as processing means, means for obtaining a point P (xp, yp) at which the intensity I (x, y) reaches a peak, and the point P (xp) , Yp) and means for obtaining an intensity distribution I (x, y) on a plurality of straight lines on the image sensor, and detecting a peak of a primary ring in each intensity distribution I (x, y). And a means for respectively counting the number of peaks of the primary ring existing in two regions on the image sensor divided by the straight line L passing through the point P (xp, yp). is there.

Eighth, the light emitted from the lens is imaged on the image pickup device, and the intensity I at the point (x, y) on the device is formed.
In a pickup inspection apparatus that performs arithmetic processing using (x, y), as processing means, means for obtaining a point P (xp, yp) at which the intensity I (x, y) reaches a peak, and the point P (xp) , Yp) and means for obtaining an intensity distribution I (x, y) on a plurality of straight lines on the image sensor, and detecting a peak of a primary ring in each intensity distribution I (x, y). And a means for respectively counting the number of peaks of the primary ring existing in four regions on the image sensor divided by two straight lines intersecting at the point P (xp, yp). is there.

Ninth, in the above first to eighth inspection devices, the intensity I (x, y) is used instead of the point P (xp, yp).
Is the center of gravity of the intensity distribution G (x
g, yg) is used to perform arithmetic processing.

[0020]

According to the present invention, the spot image from the camera controller is once stored in the frame memory and the image is subjected to arithmetic processing so that the quality of the spot can be automatically determined. Specifically, since the spot image on the image sensor is projected on the frame memory, the assumed x, y coordinates on the image sensor can be treated as the x, y coordinates of the frame memory. The intensity I of each part is determined by the coordinates (x,
y) can be treated as a function I (x, y).

When determining whether the spot is normal or abnormal, pay attention to the number of peaks (a, b, etc.) of the primary ring on the right side and the left side of a certain straight line L, and determine the number of peaks on both sides. When there is a balance, the spot is judged to be abnormal (the invention of claims 1 to 3). In addition, the number of peaks (a, b) of the primary ring in each region is divided into four regions by a combination M of two straight lines passing through a certain point P.
Etc.), the spot is judged to be abnormal when there is an imbalance between the numbers of the four regions (the inventions of claims 4 to 6).

In order to expand the function as the inspection device,
It is possible to count the number of peaks (a, b, etc.) of the primary ring on both sides of one straight line L or four regions divided by a combination M of two straight lines (claim 7). Invention of claim 8). When the intensity of the spot is generally strong and saturated near the peak, the center of gravity G (xg, y) of the intensity distribution at the point where the intensity I (x, y) is equal to or greater than the threshold value Ith.
The normality / abnormality of the spot is judged by g) (the invention of claim 9).

[0023]

[Embodiment 1] Next, the pickup inspection apparatus of the present invention will be described in detail with reference to the drawings. Although this embodiment is mainly related to the invention of claim 1, the basic principle of the hardware configuration and the determination of normality / abnormality of the spot is also related to the inventions of claims 2 to 9.

FIG. 1 is a functional block diagram showing an embodiment of the main configuration of the pickup inspection device of the present invention. 16 are the same as those in FIG. 16, 11 is a frame memory, 12 is a TV monitor similar to 9, 13 is a computer, and 14 is a display.

In FIG. 1, the configuration and operation from the housing 1 of the optical pickup to the camera controller 8 are the same as those in FIG. In the present invention shown in FIG. 1, a spot image is taken into a frame memory 11 through a microscope 7 and a camera controller 8 by a command from a computer 13, and a raw image thereof is taken in by a TV monitor 1.
Display on screen 2.

On the other hand, after outputting the command, the computer 13 applies the processes of claims 1 to 9 to the image stored in the frame memory 11 and displays the result on the display 14. Next, the intensity distribution of the spot when the inclination of the objective lens incorporated in the actuator is properly adjusted will be described.

FIG. 2 is a diagram showing an example of the intensity distribution of the spot when the inclination of the objective lens is well adjusted and there is no distortion. In the figure, x and y are the x and y axes,
I is the intensity of the spot, P is the point where the intensity peaks, 21
Indicates a spot intensity distribution curve, and 22 indicates a straight line.

As shown in FIG. 2, when the tilt of the objective lens is well adjusted and there is no distortion, the intensity distribution of the spot has a bell-shaped shape 21. Here, assuming the surface of the image sensor (generally, the image sensor is planar) on which the image of this spot is formed, the x axis and the y axis are set on this surface.

The intensity of the spot at the point (x, y) on the image sensor is I (x, y), and the peak intensity is P (xp, yp). Note that, in FIG. 2, the point P and the coordinate origin are shown as being coincident with each other for easy understanding. Next, considering the intensity distribution of the spot on the straight line 22 that passes through the point P and makes an angle θ1 with the x-axis, the result is shown in FIG. 3 below.

FIG. 3 is a diagram showing an example of the intensity distribution of spots on a straight line 22 passing through the point P and forming an angle θ1 with the x axis in FIG. In the figure, 23 is the intensity distribution curve of the spot,
24 is the primary ring, 25 and 26 are the peaks of the primary ring, and 27 is the main lobe.

The intensity distribution curve 21 of the spot shown in FIG.
Then, the intensity distribution of the spot on the straight line 22 which passes through the point P and makes an angle θ1 with the x-axis becomes a curve as shown by 23 in FIG. That is, the primary rings 24 having their peaks 25 and 26 are formed on both sides of the main lobe 27. Further, the raw image of the spot of FIG. 2 is displayed on the screen of the TV monitor 12 as shown in FIG.

FIG. 4 is a diagram showing an example of a raw image of a spot displayed on the screen of the TV monitor 12. Reference numerals in the figure are the same as those in FIG. 3, and 28 to 30 indicate certain straight lines.

The raw image of the spot on the screen of the TV monitor 12 shown in FIG. 4 is an image example when FIG. 2 is viewed from the positive direction of the I axis. As shown in FIG. 4, the spot (normal spot) in the case where the inclination of the objective lens is well adjusted and there is no distortion is that the primary ring 24 is aligned with a certain axis (x axis in this FIG. 4). The shape is almost symmetrical to that.

Therefore, the intensity distribution on the straight line 28 indicated by the chain double-dashed line is the same as that shown in FIG.
The peak of always appears in pairs. On the other hand, the intensity distribution on the straight line 29 shown by another two-dot chain line is as shown in FIG.

FIG. 5 shows a straight line 29 indicated by a chain double-dashed line in FIG.
It is a figure which shows the example about the intensity distribution above. The horizontal axis of the figure is the straight line 29 of FIG. 4, and the vertical axis shows the intensity of the spot.

As shown in FIG. 5, no peak of the primary ring appears on the straight line 29 shown by the chain double-dashed line in FIG. In addition, depending on how to select the two-dot chain line,
This may be different from FIG. 5, for example, the straight line 30 in FIG.
In the case of, one peak appears.

In the present invention, paying attention to this point, only a plurality of straight lines passing through the point P as shown in FIG. 4 are assumed, and the number of peaks of the primary ring appearing in the intensity distribution on each straight line is determined. In consideration, the number of peaks is used to inspect the spot for abnormalities. According to the result of this consideration, in the case of a normal spot, when the straight line L (here, the straight line that coincides with the y axis) is taken, the left and right sides of the straight line L show the peak of the primary ring. It can be seen that the numbers match.

This phenomenon occurs even when the straight line L is the x-axis,
It is the same. On the other hand, a primary ring having an asymmetric or irregular shape is generated at a spot (abnormal spot) where tilt adjustment is insufficient or distortion is generated.

FIG. 6 shows an example of an abnormal spot.
It is a figure which shows the case where the following ring is asymmetric. Reference numerals in the figure are the same as those in FIG. 4, 31 and 32 are primary rings, and 33 and 34 are straight lines. FIG. 7 is also an example of each abnormal spot, and (1) and (2) are diagrams showing the case where the primary ring is irregular. The reference numerals in the figure are the same as those in FIG. 6, and are 35 to 37 and 40 to 41.
Indicates a primary ring, and 38 to 39 and 42 indicate straight lines.

In the case of FIG. 6, if a straight line L (here, a straight line that coincides with the y-axis) is taken, the left side and the right side of the straight line L are 1
There is an imbalance in the number of peaks in the next ring.
The same applies to the cases of FIGS. 7 (1) and 7 (2).

Here, when the number of peaks of the primary ring on the right side of a certain straight line L is a and the number of peaks of the primary ring on the left side is b, the value (ab) or the value (a / b)
When it exceeds a predetermined value H, it is determined to be an abnormal spot. Such a judgment is made by the following steps.

A spot image is captured on the frame memory 11 of FIG. Point P (xp, y) at which intensity I (x, y) reaches a peak
p) is calculated.

A plurality of straight lines ln passing through the point P (xp, yp) are set, and the intensity distribution In (x,
y) is calculated. Here, the straight line ln is y = (tan θn)
It can be represented by x (x−xp) + yp, and θn is an angle formed by the straight line ln and the x axis.

The intensity distribution In (x,
Detect the peak of the primary ring in y). If (ab)> H or (ba)> H,
Judge the spot as abnormal. Alternatively, (a / b)>
When H or (b / a)> H, the spot may be determined to be abnormal.

The spots other than the above spots are judged to be normal. Among the above procedures (1) to (5), the procedures (1) to (9) are basically common to the inventions of claims 1 to 9, and the procedures are different.

FIG. 8 is a flow chart showing the flow of basic processing at the time of spot inspection in the pickup inspection device of the present invention. In the figure, # 1 to # 4 indicate steps.

In step # 1, the frame memory 1 of FIG.
Capture the spot image on 1. In the next step # 2,
A point P (xp, yp) at which the intensity I (x, y) reaches a peak is obtained.

In step # 3, a plurality of straight lines ln passing through the point P (xp, yp) are set, and the intensity distribution In (x, y) on each straight line ln is obtained. Proceeding to step # 4, 1 in the intensity distribution In (x, y) obtained in the previous step # 3
Detect the peak of the next ring.

The processes of steps # 1 to # 4 described above are the processes of steps 1 to 4 described above, which are common to the pickup inspection apparatus of the present invention, but the peak of the primary ring in step # 4 The detection processing is slightly different between the inventions of claims 1 to 4 and the inventions of claims 5 to 9. In the following description, the processes of steps # 1 to # 4 are called basic processes.

In this embodiment (the invention of claim 1), thereafter, the processing according to the procedure described above is performed. FIG. 9 is a flow chart showing the main processing flow during spot inspection in the pickup inspection apparatus of the present invention. In the figure, # 11 to # 14 indicate steps.

In step # 11, the processing of the flow shown in FIG. 8 is performed to detect the peak of the primary ring in the intensity distribution In (x, y). In step # 12, (ab)>
Check if H, or (ba)> H.

If (ab)> H, or (ba)
If> H, the spot is judged to be abnormal in the next step # 13, and the flow of FIG. 9 is terminated. Also, (a
-B)> H or (b-a)> H, the process proceeds to step # 14, the spot is judged to be normal, and this spot in FIG.
Ends the flow.

The process performed in step # 4 of the flow shown in FIG. 8, that is, the process for detecting the peak of the primary ring in the intensity distribution In (x, y) is well known in the art. , Shows the flow. FIG. 10 is a flowchart showing the flow of the main processing when the peak of the primary ring is detected. In the figure, # 21 to # 23 indicate steps.

In step # 21, the intensity distribution In (x, y) on the straight line L is smoothed. In step # 22, point P
The extreme value in the positive direction of the x coordinate is obtained from (xp, yp), and the point that gives the maximum extreme value is the peak of the primary ring.

In step # 23, the extreme value in the negative direction of the x coordinate is obtained from the point P (xp, yp), and the point that gives the maximum extreme value is the peak of the primary ring. Step # 21-
By the process of # 23, the peak of the primary ring in the intensity distribution In (x, y) is detected.

[0056]

Second Embodiment Next, a second embodiment will be described. This embodiment corresponds to the invention of claim 2. In the first embodiment, attention is paid to the numbers a and b of peaks of the primary rings on the right side and the left side of a certain straight line L, and (a-
If b)> H or (ba)> H, the spot was judged to be abnormal. Alternatively, when (a / b)> H or (b / a)> H, the spot was judged to be abnormal.

However, in this way, the judgment for only one straight line L may differ depending on the selection of the straight line L. For example, in the case of FIG. 6, assuming that the y-axis is the straight line L, a <b, and it is determined that the spot is abnormal, but x
When the axis is a straight line L, a = b, which is erroneously determined as a normal spot.

In the second embodiment, in order to eliminate such inconvenience, a plurality of straight lines L are selected. In this way, when a plurality of straight lines L are selected (set), there is less risk of making an erroneous determination as described above (the invention of claim 2).

In this case, if one straight line L is determined to be abnormal, the remaining straight line L is determined.
May be determined to be normal or may be determined to be abnormal as a spot, or may be determined to be abnormal as a spot only when it is determined to be abnormal for a certain number of straight lines or more. Such criteria can be arbitrarily set according to the strictness of quality required for the spot and the accuracy of measurement.

FIG. 11 is a flow chart showing the main processing flow at the time of spot inspection in the second embodiment of the present invention. In the figure, # 31 to # 37 indicate steps.

In step # 31, the processing of the flow shown in FIG. 8 is performed to detect the peak of the primary ring in the intensity distribution In (x, y). In the next step # 32, i = 1 is set. The process proceeds to step # 33 to check whether i ≦ n.

If i≤n, step # 34
Then, the spot is judged to be normal, and the flow of FIG. 11 is terminated. If i ≦ n, the process proceeds to step # 35 to check whether (ai-bi)> H or (bi-ai)> H.

If (ai-bi)> H, or (bi
-Ai)> H, i = i + in step # 36.
The value is set to 1, the process returns to the previous step # 33 again, and the same processing is performed thereafter. In addition, as a result of the judgment in step # 35,
If (ai-bi)> H or (bi-ai)> H, the process proceeds to step # 37, the spot is judged to be abnormal, and the flow of FIG. 11 is terminated.

By the processes of steps # 31 to # 37, the number of peaks of the right and left primary rings for the plurality of straight lines Li is compared with the predetermined value H. The accuracy of judgment is improved as compared with the example. In step # 35, it is determined that (ai-bi)> H or (bi-ai)> H, but instead of (a
It is also possible to judge whether i / bi)> H or (bi / ai)> H.

[0065]

Third Embodiment Next, a third embodiment will be described. This embodiment corresponds to the invention of claim 3. In the second embodiment, attention is paid to the number of peaks ai and bi of the primary rings on the right side and the left side of a plurality of straight lines Li, and (a
If i-bi)> H or (bi-ai)> H,
The spot was judged abnormal.

Also in this third embodiment, a plurality of straight lines Li
Regarding the number of peaks ai and bi of the primary rings on the right side and the left side are common, and the determination criteria are also similar. Specifically, the imbalance in the number of peaks of the primary ring is evaluated by the average value of all n straight lines Li.

According to this evaluation method, if one straight line L is unbalanced but the other straight line L is balanced, the quality of the whole is judged.
There is an advantage that it is more resistant to noise than the evaluation method of the second embodiment. In the procedure described in the first embodiment above,
It is equivalent to repeating and with n times and performing the procedure with respect to the average value of n times.

FIG. 12 is a flow chart showing the main processing flow at the time of spot inspection in the third embodiment of the present invention. In the figure, # 41 to # 49 indicate steps.

In step # 41, the spot image is captured on the frame memory 11. At the next step # 42, a point P (xp, yp) at which the intensity I (x, y) reaches a peak is obtained.

At step # 43, i = 0 and S = 0 are set. In step # 44, S = S + (ai-bi) is set. Proceed to the next Step # 45, and check whether i ≦ n.

If i≤n, the process proceeds to step # 46, i = i + 1 is set, the process returns to the previous step # 44 again, and the same processing is repeated. Also, step # 4
If i ≦ n as a result of the determination in step 5, step # 47
Go to.

At step # 47, it is checked whether (S / n)> H or (-S / n)> H. If (S / n)> H or (-S / n)> H, the spot is judged to be normal and the flow of FIG. 12 is terminated.

Further, as a result of the judgment in step # 47,
If (S / n)> H or (-S / n)> H, the process proceeds to step # 49, the spot is judged to be abnormal, and the flow of FIG. 12 is terminated. Steps # 41- # above
By the processing of 49, the imbalance in the number of peaks of the primary ring is evaluated by the average value of all n straight lines Li, so that a strong judgment on noise is realized.

[0074]

Fourth Embodiment Next, a fourth embodiment will be described. This embodiment corresponds to the invention of claim 4. In the above-described first to third examples, the normality / abnormality of the spot was judged by the imbalance in the number of peaks of the primary ring existing on both sides of the straight line.

In the fourth to sixth embodiments, the boundary line of the region is not a single straight line, but the number of peaks of the primary ring in four regions divided by two straight lines makes the spot normal. I try to judge abnormalities. Specifically, if the combination of two straight lines intersecting at the point P (xp, yp) is M, the number of peaks of the primary ring existing in the four regions is counterclockwise a, b, c, d. Value {(a
+ C)-(b + d)} or the value {(a + c) / (b +
d)} exceeds a predetermined value H, it is determined that the spot is abnormal, so that the abnormality of the spot can be more accurately determined.

In order to facilitate understanding, if the two straight lines M are the x-axis and the y-axis, a particularly remarkable effect is obtained in the case of the irregularly distorted spot as shown in FIG. 7 (2). Is obtained.
The fourth embodiment is a case corresponding to the first embodiment except that it is divided into four regions by the two straight lines M.

FIG. 13 is a flow chart showing the main processing flow at the time of spot inspection in the fourth embodiment of the present invention. In the figure, # 51 to # 54 indicate steps.

The flow of FIG. 13 is basically the same as the process of the flow of FIG. 9 described in the first embodiment,
Instead of the judgment in step # 12, in step # 52,
(A + c)-(b + d)> H, or (b + d)-(a
The difference is that whether or not + c)> H is checked.

[0079]

Fifth Embodiment Next, a fifth embodiment will be described. This embodiment corresponds to the invention of claim 5. The fifth embodiment is a case corresponding to the second embodiment described above except that it is divided into four regions by two straight lines M.

In this fifth embodiment, two intersecting straight lines M
Similarly to the second embodiment, a plurality of cases are assumed instead of one. Therefore, it is possible to more accurately determine the spot abnormality than in the fourth embodiment. Note that the flow chart also includes steps # in FIG.
Instead of the determination of 35, (a + c)-(b + d)> H, or (b + d) as in step # 52 of FIG. 13 above.
It is only necessary to check whether − (a + c)> H.

[0081]

Sixth Embodiment Next, a sixth embodiment will be described. This embodiment corresponds to the invention of claim 6. The sixth embodiment is also a case corresponding to the third embodiment described above, except that it is divided into four regions by the two straight lines M.

Also in this sixth embodiment, the imbalance in the number of peaks of the primary ring is evaluated by the average value of all the n straight lines M as a criterion similar to the above third embodiment. I have to. Therefore, it is possible to make a stronger evaluation on noise than the fifth embodiment. It should be noted that in the flowchart as well, it is only necessary to change the judgment criterion in step # 47 of FIG.

[0083]

Seventh Embodiment Next, a seventh embodiment will be described. This embodiment corresponds to the inventions of claims 7 and 8. In the above-described first to sixth embodiments, (a-b), (a + c)-(b + d), or the like is adopted as the judgment formula for evaluation.

However, in practice, there may be a case where it is better to adopt different judgment formulas depending on the difference in the tendency of the spot shape, the difference in the judgment standard to be regarded as abnormal, the measurement accuracy and the like. For such a case, means for separately counting the respective peak values a and b (and further c and d) of the primary ring is provided.

As described above, by providing the means for counting various values a, b, c, d, etc., it becomes possible to widen the use as an inspection device. FIG. 14 is a flow chart showing the main processing flow at the time of spot inspection in the seventh embodiment of the present invention. In the figure, # 61
~ # 63 indicate steps.

In step # 61, the processing of the flow shown in FIG. 8 is performed to detect the peak of the primary ring in the intensity distribution In (x, y). In the next step # 62, the value ai,
Bi is counted, and the process proceeds to step # 63 to perform the next process.

In the invention of claim 8, step # 6
At 2, not only the values ai, bi but also the values ci, di are counted. The count value obtained in the processing of steps # 61 to # 63 described above enables the inspection regarding other states of the spot as necessary.

[0088]

Eighth Embodiment Next, an eighth embodiment will be described. This embodiment corresponds to the invention of claim 9, but also relates to the inventions of claims 1 to 8. The first to seventh embodiments described above are the cases where the inspection is always performed with the point P at which the intensity of the spot has a peak as the center.

However, the intensity of the spot is strong as a whole,
When the output from the camera is saturated near the peak, the point P where the intensity reaches the peak cannot be detected. FIG. 15 is a diagram showing an example of the intensity distribution of the spot when the output from the camera is saturated near the peak. Reference numeral 43 in the figure indicates a saturated portion.

As shown in FIG. 15, when the intensity of the spot is high as a whole and the output from the camera is saturated near the peak, the intensity I (x, y) at the point P is
The center of gravity G (xg, x) of the intensity distribution at a point equal to or greater than the threshold value Ith
Substitute with yg). The center of gravity G (xg, yg) of the intensity distribution I (x, y) in this case is defined by the following equations (1) and (2).

[0091]

[Equation 5]

Here, the sum is calculated for all (i, j) where I (i, j) ≧ Ith.

The center of gravity G of obtained by such calculation
If (xg, yg) is used, the intensity of the spot can be increased and the normality / abnormality can be determined without having to worry about saturation near the peak. Further, when the strength of the entire ring is increased as described above, the strength of the ring portion is also increased, so that there is an advantage that the peak of the primary ring is easily detected.

In the eighth embodiment, the point P (x, y) in each of the above-described embodiments is replaced with the point G (xg, yg) shown in the equations (1) and (2). You can replace it. Therefore,
The invention can be applied to each invention of claims 1 to 8.

[0095]

According to the invention of claim 1, each intensity distribution I (x,
The number of primary ring peaks existing in two regions on the image sensor divided by the means for detecting the primary ring peak in y) and the straight line L passing through the point P (xp, yp) is a , B, means for comparing the value (ab) or the value (a / b) with a predetermined value H,
And have. Therefore, an abnormal spot can be detected by a simple calculation.

According to a second aspect of the present invention, means for setting a plurality of straight lines L (L1, L2, ..., Ln) passing through the point P (xp, yp) and an image pickup device divided by each of the straight lines Li. When the number of peaks of the primary ring existing in the above two regions is ai and bi, respectively, for each Li, the value (ai-bi) or the value (ai / bi) and the predetermined value H And means for comparing large and small. Therefore, an abnormal spot can be detected more accurately by a simple calculation.

According to a third aspect of the present invention, a means for setting a plurality of straight lines L (L1, L2, ..., Ln) passing through the point P (xp, yp) and an image pickup device divided by each of the straight lines Li. When the number of peaks of the primary ring existing in the above two regions is ai and bi respectively,

[Equation 6] And means for comparing the magnitude with a predetermined value H. Therefore, an abnormal spot can be detected more accurately by a simple calculation.

According to the fourth aspect of the present invention, the number of peaks of the primary ring existing in four regions on the image pickup device divided by two straight lines intersecting at the point P (xp, yp) is a, counterclockwise.
If b, c, d, then the value {(a + c)-(b + d)}
Alternatively, it has means for comparing the value {(a + c) / (b + d)} with a predetermined value H. Therefore, it is possible to detect an abnormal spot more accurately by a simple calculation, and it is particularly effective for detecting an irregularly distorted spot.

In the invention of claim 5, the point P (xp, yp)
A plurality of pairs M of two straight lines that intersect at (M1, M2, ..., M
n) When the number of peaks of the primary ring existing in the four regions on the image pickup device divided by the respective straight lines Mi is set to ai, bi, ci, di in the counterclockwise direction, each Mi is set. With respect to the value {(ai + ci)-(bi +
di)} or value {(ai + ci) / (bi + di)}
And means for comparing the magnitude with a predetermined value H. Therefore, it is possible to detect an abnormal spot more accurately by a simple calculation, and it is particularly effective for detecting an irregularly distorted spot.

In the invention of claim 6, the point P (xp, yp)
A plurality of pairs M of two straight lines that intersect at (M1, M2, ..., M
n) means for setting and the number of peaks of the primary ring existing in the four regions on the image pickup device divided by the respective sets of the two straight lines Mi to the left, ai, bi, ci, di
When

[Equation 7] And means for comparing the magnitude with a predetermined value H. Therefore, it is possible to detect an abnormal spot more accurately by a simple calculation, and it is particularly effective for detecting an irregularly distorted spot.

In the invention of claim 7, the point P (xp, yp)
And a means for counting the number of peaks of the primary ring existing in two regions on the image pickup device divided by a straight line L passing through. Therefore, it is possible to detect the spot abnormality in accordance with various determination criteria.

In the eighth aspect of the invention, the point P (xp, yp)
And means for counting the number of peaks of the primary ring existing in the four regions on the image pickup device divided by the two straight lines intersecting with each other. Therefore, it is possible to detect the spot abnormality in accordance with various determination criteria.

In the ninth aspect of the invention, the point P (xp, yp)
In place of the above, there is provided means for performing arithmetic processing using the center of gravity G (xg, yg) of the intensity distribution of the point where the intensity I (x, y) is equal to or greater than the threshold value Ith. Therefore, increase the intensity of the spot without worrying about saturation near the peak,
The normality / abnormality can be judged. Further, when the strength of the entire ring is increased, the strength of the ring portion is also increased, so that there is also an advantage that the peak of the primary ring is easily detected.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing an embodiment of the main configuration of a pickup inspection device according to the present invention.

FIG. 2 is a diagram showing an example of the intensity distribution of a spot when the tilt of the objective lens is adjusted well and there is no distortion.

FIG. 3 is a diagram showing an example of intensity distribution of spots on a straight line 22 that passes through a point P and forms an angle θ1 with the x-axis in FIG.

FIG. 4 is a diagram showing an example of a raw image of a spot displayed on the screen of the TV monitor 12.

5 is a diagram showing an example of an intensity distribution on a straight line 29 indicated by a chain double-dashed line in FIG.

FIG. 6 is an example of an abnormal spot, showing a case where the primary ring is asymmetric.

[Fig. 7] Similarly, each is an example of an abnormal spot.
(2) is a diagram showing a case where each primary ring is irregular.

FIG. 8 is a flowchart showing a basic processing flow during spot inspection in the pickup inspection apparatus of the present invention.

FIG. 9 is a flowchart showing a main processing flow during spot inspection in the pickup inspection device of the present invention.

FIG. 10 is a flowchart showing a main processing flow when a peak of the primary ring is detected.

FIG. 11 is a flowchart showing a main processing flow at the time of spot inspection in the second embodiment of the present invention.

FIG. 12 is a flowchart showing a main processing flow at the time of spot inspection according to the third embodiment of the present invention.

FIG. 13 is a flowchart showing a main processing flow at the time of spot inspection according to the fourth embodiment of the present invention.

FIG. 14 is a flowchart showing the main processing flow during spot inspection in the seventh embodiment of the present invention.

FIG. 15 is a diagram showing an example of the intensity distribution of spots when the output from the camera is saturated near the peak.

FIG. 16 is a diagram showing an example of a main part configuration of a conventional adjusting device for performing an optical head adjusting step.

[Explanation of symbols]

 1 Optical pickup housing 2 Deflection prism 3 Actuator 4 Screw 5 Objective lens 6 Cover glass 7 Microscope 11 Frame memory 12 9 TV monitor similar to 13 Computer 14 Display

Claims (9)

[Claims] 1. Intensity I (x, y) at a point (x, y) on the imaging device is formed by forming an image of light emitted from a lens on the imaging device.
In a pickup inspecting apparatus that performs calculation processing using y), as a processing means, a point P (xp, y) at which the intensity I (x, y) reaches a peak.
p), a means for obtaining an intensity distribution I (x, y) on a plurality of straight lines passing through the point P (xp, yp) and on the image sensor, and each intensity distribution I ( x, y) means for detecting the peak of the primary ring, and the number of peaks of the primary ring existing in two regions on the image sensor divided by the straight line L passing through the point P (xp, yp). , A and b respectively, and means for comparing the value (ab) or the value (a / b) with a predetermined value H, and a spot inspection of an optical pickup. apparatus. 2. Intensity I (x, y at a point (x, y) on the image pickup device is formed by forming an image of light emitted from the lens on the image pickup device.
In a pickup inspecting apparatus that performs calculation processing using y), as a processing means, a point P (xp, y) at which the intensity I (x, y) reaches a peak.
p), a means for obtaining an intensity distribution I (x, y) on a plurality of straight lines passing through the point P (xp, yp) and on the image sensor, and each intensity distribution I ( (x, y) means for detecting the peak of the primary ring, and a plurality of straight lines L (L1, L1 passing through the point P (xp, yp)).
L2, ..., Ln) setting means, and 2 on the image pickup device divided by each of the straight lines Li.
When the number of primary ring peaks existing in two regions is ai and bi respectively, a value (ai-bi) or a value (ai / b) is obtained for each Li.
i) and a means for comparing the magnitude with a predetermined value H, and a spot inspection device for an optical pickup. 3. Intensity I (x, y) at a point (x, y) on the image pickup element is formed by forming light emitted from the lens on the image pickup element.
In a pickup inspecting apparatus that performs calculation processing using y), as a processing means, a point P (xp, y) at which the intensity I (x, y) reaches a peak.
p), a means for obtaining an intensity distribution I (x, y) on a plurality of straight lines passing through the point P (xp, yp) and on the image sensor, and each intensity distribution I ( (x, y) means for detecting the peak of the primary ring, and a plurality of straight lines L (L1, L1 passing through the point P (xp, yp)).
L2, ..., Ln) setting means, and 2 on the image pickup device divided by each of the straight lines Li.
When the number of peaks of the primary ring existing in two regions is ai and bi, respectively, And a means for comparing the magnitude with a predetermined value H, and a spot inspection apparatus for an optical pickup. 4. Light emitted from the lens is imaged on an image pickup device, and an intensity I (x, y) at a point (x, y) on the device is formed.
In a pickup inspecting apparatus that performs calculation processing using y), as a processing means, a point P (xp, y) at which the intensity I (x, y) reaches a peak.
p), a means for obtaining an intensity distribution I (x, y) on a plurality of straight lines passing through the point P (xp, yp) and on the image sensor, and each intensity distribution I ( x, y) means for detecting the peak of the primary ring, and the number of peaks of the primary ring existing in four regions on the image sensor divided by two straight lines intersecting at the point P (xp, yp) When a, b, c, d are turned counterclockwise, the value {(a + c)-(b + d)} or the value {(a + c) /
(B + d)} and a means for comparing the magnitude of a predetermined value H with a spot inspection apparatus for an optical pickup. 5. The light emitted from the lens is imaged on an image pickup device, and the intensity I (x, y) at a point (x, y) on the device is formed.
In a pickup inspecting apparatus that performs calculation processing using y), as a processing means, a point P (xp, y) at which the intensity I (x, y) reaches a peak.
p), a means for obtaining an intensity distribution I (x, y) on a plurality of straight lines passing through the point P (xp, yp) and on the image sensor, and each intensity distribution I ( x, y) means for detecting the peak of the primary ring, and means for setting a plurality (M1, M2, ..., Mn) of a set of two straight lines M intersecting at the point P (xp, yp), 4 on the image sensor divided by each straight line Mi
When the number of peaks of the primary ring existing in one region is set to ai, bi, ci, di in the counterclockwise direction, the value {(ai + ci)-(bi + d) is obtained for each Mi.
i)} or the value {(ai + ci) / (bi + di)}
And a means for comparing the magnitude with a predetermined value H, and a spot inspection apparatus for an optical pickup. 6. Intensity I (x, y) at a point (x, y) on the image pickup element is formed by forming the light emitted from the lens on the image pickup element.
In a pickup inspecting apparatus that performs calculation processing using y), as a processing means, a point P (xp, y) at which the intensity I (x, y) reaches a peak.
p), a means for obtaining an intensity distribution I (x, y) on a plurality of straight lines passing through the point P (xp, yp) and on the image sensor, and each intensity distribution I ( x, y) means for detecting the peak of the primary ring, and means for setting a plurality (M1, M2, ..., Mn) of a set of two straight lines M intersecting at the point P (xp, yp), When the number of peaks of the primary ring existing in the four regions on the image pickup device divided by each set of two straight lines Mi is set to ai, bi, ci, di in the counterclockwise direction, And a means for comparing the magnitude with a predetermined value H, and a spot inspection apparatus for an optical pickup. 7. Intensity I (x, y at a point (x, y) on the image pickup device is formed by forming light emitted from the lens on the image pickup device.
In a pickup inspecting apparatus that performs calculation processing using y), as a processing means, a point P (xp, y) at which the intensity I (x, y) reaches a peak.
p), a means for obtaining an intensity distribution I (x, y) on a plurality of straight lines passing through the point P (xp, yp) and on the image sensor, and each intensity distribution I ( x, y) means for detecting the peak of the primary ring, and the number of peaks of the primary ring existing in two regions on the image sensor divided by the straight line L passing through the point P (xp, yp). A spot inspection device for an optical pickup, comprising: 8. Intensity I (x, y at a point (x, y) on the image pickup device is formed by forming light emitted from the lens on the image pickup device.
In a pickup inspecting apparatus that performs calculation processing using y), as a processing means, a point P (xp, y) at which the intensity I (x, y) reaches a peak.
p), a means for obtaining an intensity distribution I (x, y) on a plurality of straight lines passing through the point P (xp, yp) and on the image sensor, and each intensity distribution I ( x, y) means for detecting the peak of the primary ring, and the number of peaks of the primary ring existing in four regions on the image sensor divided by two straight lines intersecting at the point P (xp, yp) A spot inspection device for an optical pickup, comprising: 9. The inspection apparatus according to any one of claims 1 to 8, wherein instead of the point P (xp, yp), the center of gravity G of the intensity distribution at a point where the intensity I (x, y) is equal to or greater than a threshold value Ith. (Xg, y
A spot inspection device for an optical pickup, characterized in that it is provided with means for performing arithmetic processing using g).