JPS61288687A - Rotation adjusting method for solid-state image pickup element - Google Patents

Abstract

PURPOSE:To adjust the rotation of the solid-state image pickup element by rotating the solid-state image pickup element up to a position where the phase of a pair of beat components is coincident based upon the difference between the picture element pitch of the solid-sate image pickup element and the repeating pitch of a test chart for measuring the registration. CONSTITUTION:The repeating pattern of the chart 10 for measuring the registration is picked up through a master lens 20 by CCD image sensors 31r, 31g and 31b. The central part of two mutually parallel stripe-shaped repeating pattern is selectively taken out by gate circuits 42r, 42g and 42b. Respective beat components included in respective beat components of the central part have the phase difference in accordance with the rotation error of an image sensor 31. Then, while respective beat components are observed by the oscilloscope, the image sensor is rotated, and thereby, the rotation can be adjusted.

Description

[Detailed description of the invention] Hereinafter, the present invention will be explained in the following order.

A5 Industrial field of application B8 Summary of the invention C0 Prior art 0 Problems to be solved by the invention E0 Means for solving the problems F1 Effect G, Example c-1 Regis; ~ Configuration of ration adjustment device (See Figure 1) Configuration of test chart for G-2 registration measurement (See Figures 2 and 3) G-3 Adjustment operation procedure (See Figures 4 to 6) Effects of the H1 invention A. Industrial Application Field The present invention relates to a charge coupled device (CCD) used as an image sensor in a solid-state imaging device.
The present invention relates to a rotation adjustment method for a solid-state image sensor, which is applied when performing so-called registration adjustment, etc., in which a solid-state image sensor such as an image sensor (Device), etc. is arranged at a predetermined position of an imaging optical system.

B0 Summary of the Invention The present invention provides a method for performing so-called registration adjustment, etc., in which a solid-state image sensor used in a solid-state image sensor is arranged at a predetermined position in an imaging optical system, when the repetition pitch is a predetermined pixel pitch of the solid-state image sensor. Regarding the imaging output of a pair of repetitive patterns in corresponding areas on the left and right or top and bottom across the center of the screen obtained by imaging a repeating pattern that repeats light and shade at a repeating pitch with the above-mentioned solid-state imaging device, the above-mentioned solid-state imaging Rotation adjustment of the solid-state image sensor is performed by rotating the solid-state image sensor around the center so that the phases of the pair of beat components based on the difference between the pixel pitch of the element and the repetition pitch match. This allows for easy operation and high accuracy.

C9 Conventional technology In general, in a color imaging device, imaging light is separated into multiple color components by a color separation system, and a subject image of each color component is captured using a solid-state image sensor such as CCI or an imaging tube. A standard color television signal such as the NTSC system is formed and output from each image pickup output obtained.

In a color imaging device using a plurality of image sensors, it is necessary to reliably maintain a state in which subject images of each color component imaged by each image sensor are aligned, that is, so-called registration adjustment is performed accurately.

In the conventional so-called three-tube color video camera, a three-color separation prism and three image pickup tubes are mechanically attached to a housing formed by die-casting, etc., and the output signal of a test chart, etc. is captured. Registration adjustment for each image pickup tube was performed by mechanically adjusting the position and then finely adjusting the position of the image pickup screen using the image pickup tube's deflection system.

For such a three-tube color video camera, CC
In a solid-state color imaging device that uses a solid-state imaging device such as D as an image sensor, it is not possible to electrically adjust the imaging screen position like an imaging tube, so each solid-state image sensor that captures a subject image of each color component is In addition to bonding a holder made of iron or the like, a holder is also bonded to each light emitting part of the color separation prism of the color separation system, and the adjustment direction is shown in Figure 7 for each image sensor. As shown with an arrow, (11 Horizontal center (arrow/mark ±X direction) adjustment (2) Vertical center (arrow ±Y direction) adjustment (3) Hack focus (arrow ±Z direction) Adjustment (4) Horizontal tilt (arrow ±RX direction) Adjustment (5) Vertical tilt (arrow ±R)
Y direction) adjustment (6) Rotation (arrow ±RZ direction)
tI! After performing six-axis registration adjustment, each solid-state image sensor was fixedly attached to each exit surface of the color separation prism by heat-welding each holder by soldering or the like.

D9 Problems to be Solved by the Invention In general, solid-state image sensors such as CODs cannot electrically adjust the position of both sides of the image like an image pickup tube, so in a color imaging device using a plurality of solid-state image sensors, It is necessary to mechanically maintain the registration of each image sensor with extremely high precision. In particular, in a solid-state color imaging device that employs the so-called spatial pixel shifting method to achieve high resolution, the above-mentioned ±X direction, arrow ±Y direction, ±Z direction, ±RX, ±RY direction, and ±RZ direction 6
It is necessary to ensure registration on the order of 1 μm in the axial direction, and conventionally, the above-mentioned registration adjustment has required a great deal of effort and time.

Therefore, in performing the registration adjustment in the six-axis directions described above, the method of the present invention aims to make it possible to perform the registration error in the RZ direction, that is, the rotation adjustment of the solid-state image sensor, with high precision with a simple operation. purpose.

1. Means for Solving the 0 Problems In the method for rotation adjustment of a solid-state image sensor according to the present invention, in order to solve the above-mentioned problems, the rotation adjustment method of the solid-state image sensor according to the present invention has the purpose of solving the above-mentioned problems. The above-mentioned solid-state imaging device captures an image in which a pair of repeating patterns repeating shading in the horizontal or vertical direction in corresponding portions, the repeating pitch of which has a predetermined relationship with the pixel pitch in the horizontal or vertical direction of the solid-state imaging device. A pair of beat components based on the difference between the pixel pitch of the solid-state image sensor and the repeating pitch are detected for the imaging output of a pair of repeating patterns of portions corresponding to the left and right or top and bottom of the screen, and The solid-state imaging device is characterized in that the solid-state imaging device is rotated about the center portion and the rotation is stopped at a position where the phases of the pair of beat components match.

F1 action In the rotation adjustment method for a solid-state image sensor according to the present invention, a pair of repeating patterns that repeat shading in the horizontal or vertical direction are applied to portions corresponding to the left and right or top and bottom of the screen of the solid-state image sensor. The image output obtained by capturing an image with the solid-state image sensor, the repetition pitch of which has a predetermined relationship with the pixel pitch in the horizontal or vertical direction of the solid-state image sensor, is -
A beat component based on the difference between the F picture element pitch and the repetition pitch is included. "-The phase of the beat component described above is ±
It changes depending on the registration error in the X direction, the arrow ±Y direction, and the ±RZ direction.

Based on the difference between the pixel pitch of the solid-state image sensor and the repeat pitch, the imaging output of a pair of repetitive patterns corresponding to the left and right or top and bottom portions of the screen obtained by the solid-state image sensor is determined based on the difference between the pixel pitch of the solid-state image sensor and the repeat pitch. By rotating the solid-state image sensor around the center so that the phases of the pair of beat components match, rotation adjustment of the solid-state image sensor can be performed with high precision with a simple operation.

G. Example Hereinafter, an example of the rotation adjustment method for a solid-state image sensor according to the present invention will be described in detail with reference to the drawings.

In the embodiments shown in FIGS. 1 to 6, the present invention is applied to a registration adjustment device for performing registration adjustment of a three-chip COD color video camera.

G-1. Configuration of Registration Adjustment Apparatus The registration adjustment apparatus in this embodiment has a registration measurement test chart 1 on which a predetermined test pattern is formed, as shown schematically in FIG.
0 is placed in front of the master lens 20. The imaging light of the test pattern by the registration measurement test chart 10 is guided through the master lens 20 to the color separation prism 30 of the three-plate COD color video camera, and the color separation prism 30 converts the imaging light into three primary colors. Three CCD image sensors 31r and 31g separate the light into R-G-B, that is, red component light R2, green component light G, and blue component light B.

31b. Each of the CCD image sensors 31r, 31g, and 3lb is provided with a position adjustment jig 4. for six-dimensional positioning. Or, 40g
.

40b, respectively. The CCD image sensors 31r, 31g, and 31b are as follows:
It is driven by a CCD drive circuit 51 that operates based on a reference signal provided by a reference signal generator 50, and images an image, that is, a test pattern, using imaging light of each color component separated by the color separation prism 30. Each of the above CCDs
The imaging outputs obtained by the image sensors 31r, 31g, 3lb are sent to preamplifiers 41r, 41, respectively.
g, 4 lb to each gate circuit 42r, 42g, .
The signal is supplied to the matrix circuit 43 via 42t+. Here, each of the gate circuits 42r, 42g, and 42b is supplied with a gate pulse generated by a gate pulse generating circuit 52 that operates based on the reference signal.

The image output signal obtained by the matrix circuit 43 is
It is supplied to an oscilloscope 44 for wave observation, and is also supplied to a high-resolution monitor 46 via a video signal processing circuit 45.
It is further supplied to a microcomputer 48 via a digitizer 47.

G-2. Configuration of registration measurement test chart 1- The above registration measurement test chart 10 is as follows:
As schematically shown in FIG. 2, the CCD image sensor 3
For a pixel pitch τC of 1, τp−2τC±Δ・
...The first equation (where Δ is set to Δ-τC・τp/τ0, where the effective image area size in the picture element arrangement direction is τ0.) The repetition pitch τp has the relationship of the first equation: The CCD image sensor 31 is provided with an image of a repeating pattern PT in which shading is repeated.

In this example, the iJ registration measurement test 1-10 has a test pattern aligned with the horizontal center line T, , sh, as schematically shown in FIG. ti (striped repeating pattern PTsh, - the horizontal center line Lsh)
Two vertical striped repeating patterns PTah and PTbh arranged symmetrically and parallel to the loaf, and a vertical center line L
Two horizontal striped repeating patterns PTaν and PTbv arranged symmetrically with sv in between and parallel to each other are used.

Here, each of the vertical striped repeating patterns PTsh,
P T'ah and P Tbh are formed to repeat shading at a repetition pitch τph that is in the relationship expressed by the first equation described above with respect to the horizontal pixel pitch τch of the CCl) image sensor 31. Further, the horizontal striped repeating pattern P Tav, P T”bv, the above C
With respect to the vertical pixel pitch τCV of the CD image sensor 31, the light and shade are repeatedly formed at a repetition pitch τpv that has the relationship expressed by the first equation.

In addition, in this embodiment, one test chart can be used in common to perform registration measurements for CCD image sensors with two types of pixel arrays that correspond to the CCrR and EIA standards. Two types of test patterns corresponding to CCIR and EIA standards are provided side by side.

Test chart 1 for registration measurement as described above
The imaging output obtained by the CCD image sensor 31 irradiated with the imaging light of the test pattern based on 0 is based on the repetition pitch τp of the repetition pattern PT and the pitch of each pixel τ
A moiré pattern is generated based on the difference from C, and the signal level changes as shown in FIG. 2 depending on the relative position of the repeating pattern PT and each picture element S. In other words, in the imaging output for the horizontal repeating pattern PTh, the fourth
As shown in the figure, six beat components are included in one horizontal scanning period (IH).

The beat component included in the imaging output signal obtained by imaging the repeating pattern of the registration measurement test chart 10 by the CCD image sensor 31 has an amplitude that is equal to the bank focus of the imaging optical system and the tilt amount of the solid-state imaging device. 2) The phase changes depending on the registration error of the ball in the ±Z direction and the ±RX, ±RY directions, and the phase changes depending on the center position and rotation of the solid-state image sensor, i.e., the above-mentioned ±X direction, arrow ±Y It changes depending on the direction and the registration error in the ±RZ direction.

G-3. Procedure of Adjustment Operation Therefore, in this embodiment, the above-mentioned position adjustment jigs 40r and 40g of the above-mentioned registration adjustment device are used.

Each CCD image sensor 31r attached to 40b.

31g and 31b are in a driving state to image the repeating pattern of the test chart 10 for measuring strain, and each of the CCD image sensors 31r.

31g and 31b (for the imaging output M), each beat component shown in FIG.
waveform observation or the above Microconobi 1-Y48
While performing waveform analysis using
r, 40g, 40b'? c operation, and each of the above CCD image sensors 31r, 31g, 3 in the next step.
] b is subjected to six-dimensional alignment.

In this embodiment, each CCD image sensor 31r, 31
First, the bank focus adjustment and the tilt adjustment are performed for the lenses g and 31b.

” The hack focus adjustment and tilt adjustment are performed by each CCD image sensor 3 via the master lens 20.
1r, 31. The amplitude of the beat component contained in the imaging output signal obtained by imaging the repeating pattern of the test chart 10 for registration measurement using 3 lbs. direction, and registration errors in the ±RX and ±RY directions, the hack focus of the imaging optical system, and each CCD image sensor 31r, 31g,
It changes depending on the amount of tilting of 3 lb, and each CCD above
Since the maximum value is reached when the image sensors 31r, 31g, and 3lb are in the just focus position, "1"
While observing the waveform of the heat component using the oscilloscope 44, - each of the position adjustment jigs 4. Or, 40g
, 40b to detect the position where the amplitude of the heat component is maximum.

Next, each CCD image sensor 31 whose imaging plane has been determined by the hack focus adjustment and tilt adjustment described above.
r, 31g, and 3 lb, use the horizontal and vertical center lines Lsh+Lsν of the registration measurement test I-Char 1 and 10 to roughly adjust the center adjustment and rotation adjustment in the horizontal and vertical directions. I do.

In other words, since the pixel located at the center of the imaging surface of the CCD image sensor 31 is fixed, a cross-shaped reference image centered on this pixel is created as shown by the solid line in FIG. The test chart 10 for registration measurement described in "2" is displayed on the screen of the high-resolution monitor 46, and the test chart 10 for registration measurement is displayed on each CCD image sensor 31r, 31g, 3
The horizontal and vertical directions of the above-mentioned registration measurement tests 1-1 and 10 are imaged at lb and monitored on the screen of the high-resolution monitor 46 as shown in FIG. 5, for example. Center line of direction L sh, L sv
The position adjustment jigs 4 Or, 40g, and 40b are operated so that the image matches the cross-shaped reference image.

Through this adjustment operation, each CCD image sensor 31r,
The horizontal and vertical centers and rotations of 31g and 3 lb are roughly adjusted to about ±3μrn, and each CCD image sensor 31r, 31g, 311) is adjusted to % pixel with respect to the registration measurement test 1 and chart 10. Registration is adjusted within pitch.

In the rotation adjustment operation, each CCD image sensor 31r, 3
Regarding the imaging output signal obtained by imaging the repeating pattern of the registration measurement test chart 10 using 1g and 3 lb, the imaging output signals are arranged symmetrically across the horizontal center line Lsh schematically shown in FIG. 3 above. Two vertical striped repeating patterns parallel to each other PTab, PTbh
The image output of each central portion Cu, Cd is output from each gate circuit 42r.
, 42g, 42b. Each beat component included in the image output of the central portions Cu and Cd of both measuring sections has a phase difference corresponding to the above-mentioned registration error in the ±RZ direction, that is, the rotation error of the CCD image sensor 31. ing.

Therefore, while observing the waveforms of each beat component included in the image output of the central portions Cu and Cd of both measuring sections with the oscilloscope 44 as shown in FIG. 6, the respective position adjustment jigs 40r, 40g, and 40b are Rotation adjustment is performed by rotating each CCD image sensor 31r, 31g, and 3lb to a position where the phases of the respective beat components match.

In this embodiment, each CCD image sensor 31r, 3
1g and 3 lb, first, the horizontal center line Ls of the registration adjustment test chart 10 is
Vertical striped repeating pattern P that repeats shading along h
Hassoku focus adjustment is performed using the change in amplitude of the beat component included in the central AS imaging output of Tsh, and the above-mentioned registration adjustment test chart 10
Both sides Ba, B of the vertical striped repeating pattern PTsh
b and two vertical striped repeating patterns PTah that are symmetrically arranged and parallel to each other across the horizontal center line Lsh,
Using changes in the amplitude of the beat components included in the imaging outputs of each central portion Co and Cd of PTbh, horizontal and vertical tilt adjustment is performed, and furthermore, the vertical striped repeating patterns P Tah and P Tbh are adjusted. Each central part Cu
, Cd and horizontal striped repeating pattern PTav.

By using the change in the phase of the beat component included in each imaging output of the central part Da and Db of PTbv and performing rotation adjustment and center adjustment in the horizontal and vertical directions, all the resists in the above six axis directions can be adjusted. ration adjustments can be completed with extremely high accuracy.

H0 Effects of the Invention As is clear from the description of the above-mentioned embodiments, in the solid-state image sensor rotation adjustment method according to the present invention, the rotation adjustment method of the solid-state image sensor according to the present invention applies a rotation adjustment method to the left and right or top and bottom portions of the solid-state image sensor, respectively. A pair of repetitive patterns that repeat light and shade in the horizontal or vertical direction, the repetition pitch of which has a predetermined relationship with the pixel pitch in the horizontal or vertical direction of the solid-state image sensor, which is obtained by capturing an image with the solid-state image sensor. Regarding the imaging output obtained by the solid-state imaging device, the pixel pitch of the solid-state imaging device and the repetition pitch included in the imaging output of a pair of repetitive patterns corresponding to the left and right or top and bottom sides of the center of the screen obtained by the solid-state imaging device are determined. The rotation adjustment of the solid-state image sensor is performed with a simple operation and with high precision by rotating the solid-state image sensor as described above so that the phases of the pair of heat components match based on the difference between the two. and can fully achieve the intended purpose.

[Brief explanation of the drawing]

1 to 6 are drawings showing an embodiment of the lens I/ration adjustment device to which the present invention is applied. FIG. 1 is a block diagram schematically showing the configuration of the registration adjustment device of this embodiment. FIG. 2 is a schematic diagram for explaining the relationship between the test pattern of the test chart for registration measurement in the above embodiment and the sensor array of the CCD image sensor, and FIG. FIG. 4 is a schematic diagram showing the configuration of the test chart for registration measurement, and FIG. 4 shows a beat component included in the imaging output obtained by imaging the test pattern of the test chart for registration measurement with a CCD image sensor. FIG. 5 is a schematic diagram for explaining the coarse adjustment operation of the registration of the CCD image sensor in the above embodiment, and FIG. 6 is a waveform diagram used for the rotation adjustment operation of the CCD image sensor in the above embodiment. FIG. FIG. 7 is an external perspective view of a CCD image sensor for explaining the direction of adjustment operation for general registration adjustment. 10...Test chart 20...Master lens 30...Color separation prism

Claims (1)

[Claims] A pair of repeating patterns that repeat shading in the horizontal or vertical direction on the left and right or top and bottom sides of the screen across the center of both imaging surfaces of a solid-state image sensor, the repeating pitch being An image having a predetermined relationship with the pixel pitch in the horizontal or vertical direction of the solid-state imaging device is captured by the solid-state imaging device, and the imaging output of a pair of repetitive patterns corresponding to the left and right or top and bottom of the screen is A pair of beat components based on the difference between the pixel pitch of the image sensor and the repetition pitch are detected, and the solid-state image sensor is rotated about the center to detect the beat components at a position where the phases of the pair of beat components match. A rotation adjustment method for a solid-state image sensor that stops rotation.