JPH04122192A - Teat equipment for color image pickup device - Google Patents

Abstract

PURPOSE:To reduce the effect of a charge transfer structure specific to the color image pick up device and to improve the accuracy of the test by adopting a high brightness to a part of a test screen corresponding to a test part of the color image pickup device and its vicinity and adopting a low brightness to other parts. CONSTITUTION:Parts SK, SL, SM, SN of a test screen 2A are high brightness parts and other parts is suppressed to a low brightness, while a conventional test screen has optically a uniform brightness. Similarly to the case with a conventional test screen, the high brightness parts SK, SL, SM, SN of the test screen 2A through an optical mechanism 1b are correspond to parts Sk, Sl, Sm, Sn of a color image pickup device 1a respectively. Thus, the signal amplitude other than the test position on the color image pickup device and its vicinity is suppressed small, the effect of a charge transfer structure specific to the color image pickup device such as a CCD structure is reduced and color unevenness or a sensitivity characteristic of the color image pick up device is accurately tested.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to the improvement of color unevenness in color imaging devices used for testing in the manufacturing process of color imaging devices, and for characteristic analysis and evaluation tests of color imaging devices. The present invention relates to a testing device for a color imaging device in the field of imaging, which makes it possible to test characteristics such as sensitivity characteristics.

[Conventional technology]

In recent years, color video cameras have rapidly become popular, mainly for consumer use. Color video cameras are rapidly becoming smaller, lighter, and more sophisticated. Along with this, the requirements for color imaging devices used in color video cameras are also similar, and therefore, as a test device for color unevenness and sensitivity characteristics of color imaging devices,
There is a need for a device that can be used for detailed and highly accurate testing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A conventional testing device for a color imaging device will be described below with reference to the drawings.

FIG. 7 (al) shows the configuration of a conventional test device for a color imaging device.

In FIG. 7 (al), I is a color video camera section, which is composed of a color image pickup device 1a, an optical mechanism 1b, and a video signal circuit IC.

Further, the video signal circuit 1c is composed of a circuit that takes out an electric signal from the color imaging device 1a, and a circuit that converts the signal taken out from the color imaging device 1a into a video signal and outputs the video signal. 2 is a test screen, and 3 is an output device for testing the characteristics of the color imaging device la using the output signal of the video signal circuit IC as an input signal.

The operation of the test device for a color imaging device configured as described above will be described below.

The entire surface of the test screen 2 is kept optically uniform, and the color imaging device 1a is connected to the test screen 2 via the optical mechanism 1b.
Form an image on the image. At this time, by keeping the entire surface of the test screen 2 uniform, the color imaging device 1a
Each part is also placed in an optically uniform environment.

Now, as a defect in the electrical characteristics of the color imaging device 1a,
There may be color unevenness defects in the video signal and defects in the sensitivity characteristics of the photoelectric cell.

First, one of the causes of color unevenness defects will be explained with reference to FIG.

FIG. 8 (al shows the arrangement of photoelectric cells in the imaging element constituting the light-receiving surface of the color imaging device 1a.

Here, X+-+, X+, X+*+Vr-+,'/
r and y1+I indicate the positional relationship of an array of arbitrary photoelectric cells arranged on the image sensor, and C1 is a set of photoelectric cells located at the position (++, ++) on the image sensor.

Figure 8 (bl, (C1, (dl) is Figure 8 (a) i:
An example of the structure of the illustrated set of photoelectric cells C1 is shown in an enlarged manner. The photoelectric cell C1 includes four photoelectric cells Cl
l01□2, C112, CI+4 and the corresponding color filters fIII, fl+2
, fi12, and f114. The photoelectric cell C++ consists of four photovoltaic cells C+
+, Czt, C113, and CI+4 collectively function as one set of color photocells C1.

FIG. 8(b) shows color filter fl11. f+I□f
1lff and f114 are correctly arranged directly above the corresponding photoelectric cells Cz+, Czx, C112, and Cza. However, in FIG. 8 (C1), the color filter Let is not directly above the corresponding photoelectric cell C112, and there is a positional shift.The protruding portion wl of the photoelectric cell C11! has the color filter f,... It's fleeting.

Therefore, the signal output of the photoelectric cells C1 and C2 is no longer normal, which is one of the causes of color unevenness in the video signal.

In FIG. 8(d), four color filters fIIIf
IIl, fzz, fl□4 or the corresponding charging cells C++, CI+2, C112, C11
It is not arranged correctly directly above 4, and there is a misalignment. The photoelectric cell C, 4 has a color filter f11.
There is a protruding part w2 from 4. Therefore, Fig. 8 (
As in case C), the signal outputs of the photoelectric cells C1 and C4 are no longer normal, which is one of the causes of color unevenness in the video signal.

In addition, if the cell is covered with a color filter (not shown) or which should correspond to another photovoltaic cell, color unevenness may occur.

Next, a defect that causes variations in the sensitivity characteristics of charging cells will be explained.

The causes of this defect include variations in the optical transmittance of color filters on the photovoltaic cells, and variations in the optically effective area of the photovoltaic cells.

Currently, these characteristic tests are carried out by using a device like the one shown in Figure 7 on a fishing boat, inputting the signal obtained from the video signal circuit IC to a video monitor device such as a television receiver, and monitoring the entire surface of the monitor screen. The color imaging device 1a is tested by visual sensory tests and electrical measurements of video signals.

[Problem to be solved by the invention]

However, the above conventional configuration causes the following problems.

As shown in FIG. 7 (al), L, M, and N are 1, m, and 1, respectively, on the color imaging stand la when passing through the optical mechanism 1b.
Corresponds to n. In this way, on the part on the test screen 2, L, M, N and on the part on the color imaging stand la,
], m+n are in the vertical, horizontal, or reverse positional relationship, respectively, but for convenience of explanation, in FIG.
and the part on the color imaging stand la, 1. m,
n is shown as having the same positional relationship vertically and horizontally.

FIG. 9(a) shows the scanning J! of a monitor screen of a general television receiver called NTSC or PAL system. (
(also called raster). 9th
In the part shown in Figure (a), 1. m and n are the same as those shown in FIG. 7 (C1) and are test parts.

FIG. 9(b) shows a test portion I or a test portion m on the color imaging stand la shown in FIG. 9(a).
It shows one signal to a scanning line including n, and shows that every part is a uniform signal.

In addition, FIG. 9(C) shows, in the case of a color imaging device 1a such as a CCD structure, a test portion when there is signal variation (error) F due to the influence of the fixed growth characteristics of the color imaging device 1a. 1 or the scan line A containing the test portion mn
One signal is shown.

Figure 9 (The peak is Figure 9 (C1 signal variation (error) F
This is an enlarged version of the part corresponding to . Fl indicates the error in test portion k or n, and F2 indicates the error in test portion l or m.

The error F2 in the test portion l or m is much larger than the error Fl in the test portion k or n. This is due to the influence of the charge transfer structure of the color imaging device ft1a, such as a CCD structure, and is caused by the signal magnitude, signal duration, etc.

Thus, in the test part, 1 or test part m.

Since errors Fl and F2 occur in n, it is difficult to easily and stably obtain accurate test results in the case of a color imaging device 1a such as a CCD structure in a visual sensory test conducted in an optically uniform environment. There is a problem.

FIG. 10(a), (bl shows the structure of the color imaging device 1a, 4 is a package of the color imaging device 1a, and 5 is an imaging element.

In FIG. 10(a), the imaging element 5 is correctly fixed to the die pad (not shown) of the package 4, but in FIG. It is fixed with some positional deviation.

FIG. 10(C) shows the test portion k in the case of FIG. 10(a).
.

1, m, n and Figure 1 theta (test part k for bl.

1', m', and n' are shown on one imaging element 5.

When fixing the imaging element 5 in the package 4 of the color imaging device 1a, if a positional shift as shown in Fig. 1O (bl) occurs, ', 1', mn' on the test part are confirmed to have been correctly fixed. In the test part in the case of Fig. 1θ (a), 1. m
, n, a positional relationship shift as shown in FIG. 1O (C) occurs. For this reason, when the imaging element 5 is not properly fixed in the package 4 of the color imaging device 1a, it is not possible to accurately test the characteristics of the color imaging device 1a, and the color imaging device 1a used in the video camera cannot be accurately tested. There is a problem that color unevenness and sensitivity characteristics cannot be fully evaluated.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to provide a testing device for a color imaging device that can accurately test color unevenness and sensitivity characteristics of a color imaging device.

[Means to solve the problem]

The test device for a color image pickup device according to claim (1) is characterized in that a portion of the test screen corresponding to a test location of the color image pickup device and its vicinity is made to have high brightness, and other portions are made to have low brightness. The test device for a color image pickup device according to claim (2) is the test device for a color image pickup device according to claim (11), which receives the output signal of the color image pickup device as an input, and uses the high brightness of the test screen as an input. A correction arithmetic processing device is provided to distinguish between the high-brightness portion and other portions, and to correct the positional deviation of the imaging element so that the portion corresponding to the interior of the high-brightness portion is used as a test location for the color imaging device. .

The testing device for a color imaging device according to claim (3) is the testing device for a color imaging device according to claim (1) or claim (2), in which the shape of the high brightness portion of the test screen is tested. The location is arranged to correspond to the center of the high brightness portion.

[Effect]

According to the configuration described in claim (1), the portion of the test screen corresponding to the test location of the color image pickup device and its vicinity is made high brightness, and the other portions are made low brightness, so that the color image pickup device The amplitude of the signal at a portion other than the above test location and its vicinity can be suppressed to a small level, and the influence of a charge transfer structure specific to a color imaging device such as a CCD structure can be reduced.

According to the configuration recited in claim (2), in addition to the configuration recited in claim (11), by providing a correction arithmetic processing device,
It is possible to distinguish between high-brightness parts and other parts of the test screen, and to correct the positional deviation of the imaging element so that the part corresponding to the inside of the high-brightness part is used as the test point of the color imaging device. .

According to the configuration described in claim (3), in the configuration described in claim (1) or claim (2), the shape of the high brightness portion of the test screen corresponds to the test location or the center of the high brightness portion. By adjusting the position, even if the high-brightness portion of the test screen is made smaller, the correction arithmetic processing device can correct the test location to a desired test location.

〔Example〕

An embodiment of the invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a testing device for a color imaging device according to an embodiment of the present invention. In FIG. 1, 2A is a test screen, and lO is a correction arithmetic processing unit. The other configurations are the same as those of the conventional example, and the same reference numerals are given to the parts corresponding to FIG. 7 (al).

This test screen was used by two people, whereas the entire surface of the conventional test screen 2 was kept optically uniform.
, SL, SM, and SN are high brightness parts, and the brightness of other parts is kept low. As in the past, the high-brightness parts SK, SL, SM, and SN on the test screen 2A correspond to the parts Sk, Sl, Sm, and Sn on the color imaging stand la, respectively, when passing through the optical mechanism 1b. .

FIG. 2(a) shows the image formation on the color imaging stand la,
Sk, Sl, Sm, and Sn are the same as in Fig. 1, and are the test point and its neighboring part (hereinafter referred to as [test part j]),
Test parts Sk, Sl, Sm.

Sn corresponds to the high brightness parts SK, SL, SM, and SN on the test screen for two people, so the amplitude and thickness of the signal output from the video signal circuit 1c (and the other parts are the amplitudes of the signals). becomes smaller.

FIG. 2(b) shows test portions Sk, Sl or test portions Sm, S on the color imaging stand Ia shown in FIG. 2(al).
One signal of scan lines including n is shown.

FIG. 2(C) shows test portions Sk and Sl when there is signal variation (error) E due to the influence of the inherent characteristics of the color imaging device 1a in the case of a color imaging device 1a such as a CCD structure. Alternatively, one signal to the scanning line including the test portions Sm and Sn is shown.

Figure 2 Fdl is the signal variation (error) in Figure 2 (C).
This is an enlarged view of the part corresponding to E. El indicates the error in the test portion Sk or Sn, and E2 indicates the error in the test portion S1 or Sm. Test part S
The difference between the error El in k or Sn and the error E2 in the test portion Sl or Sm is as shown in FIG. 9(d) of the conventional example.
The difference between the error Fl and the error F2 shown in FIG.

In this way, the test portion Sk on the color imaging stand Ia,
High brightness areas SK, SL, SM on test screen 2A corresponding to SL, Sm, Sn.

By suppressing the brightness of the parts other than SN, the test parts Sk and Sl on the color imaging stand la.

The amplitude of the signal in parts other than Sm and Sn can be suppressed to a small level,
The influence of the charge transfer structure unique to the color imaging device 1a, such as the COD structure, can be reduced, and the accuracy of the test can be improved.

Below, the test location on the color main image pickup device la is shown as the test portion S.
k, S1. A correction arithmetic processing unit IO for correcting Sm and Sn to the center will be described.

This correction arithmetic processing device 10 is for correcting the position of the test portion when the imaging element 5 is not properly fixed in the package 4 of the color imaging device 1a and is misaligned. .

3(al) and (b) show the case where the imaging element 5 fixed in the package 4 is misaligned,
Test portions Sk, Sl, Sm, and Sn are test screen 2
High-brightness areas on humans SK, SL, SM.

Compatible with SN. qk, ql in Figure 3(a).

qm and qn are test points when no correction regarding positional deviation is performed, and pk and pi in FIG. 3(b).

pm and pn are test points when the correction arithmetic processing device 10 performs correction regarding positional deviation.

FIG. 4(a) shows the scanning line signal (video signal) including the test points qk and ql in FIG. 3(a), and FIG. 4(b) shows the test points qm and ql in FIG. 3(a). A scanning line signal (video signal) including qn is shown. Figure 4 (C1 is Figure 3 (
Fig. 4(d) shows the signal (video signal) of the scanning line including the test points pk and pi in Fig. 3(b). It shows. Also, d ma+d in Fig. 4 ta+~fd),
,cL,,d,,,dkb,d,,,d,,,dゎ,are respectively the points where the amplitude of the video signal changes from small to large (corresponding to the high brightness parts SK, SL, SM, and SN). test points qk, ql from the beginning of the video signal).

These are the times until qm, qn, pk, pl, pm, and pn.

As shown in FIG. 4(C) and (dl), the correction arithmetic processing unit IO calculates the high brightness areas SK and S on the test screen by comparing the reference voltage α and the video signal.
Detects the beginning of the video signal corresponding to L, SM, and SN,
Based on this first information, the test area is set to the high brightness area SK,
pk, pi, pm corresponding to the center of SL, SM, SN,
pn. Therefore, the time d kb
The variation in r d l l + d mb + d1 is
Time d, , d, , when the positional deviation shown in FIGS. 4(a) and 4(b) is not corrected.

It is smaller than the variation in d, , d, .

In addition, in order to further improve the test accuracy, the high brightness portions SK and SL of the test screen 2A.

All you have to do is make SM and SN smaller.

However, when the high-brightness portions SK, SL, SM, and SN are made small, the test location may not correspond to the center of the high-brightness portions SK, SL, SM, and SN by the correction arithmetic processing unit IO.

Hereinafter, a description will be given of the shape of the high brightness portion of the test screen 2A so that the test spot on the color main image pickup device la reliably corresponds to the center of the high brightness portions SK, SL, SM, and SN.

FIG. 5 shows a test portion S on the color main image pickup device la corresponding to one high-luminance portion of two test screens, and P is a desirable test location. Further, arrow H indicates the relationship to be corrected between the leading position of the video signal corresponding to the high-brightness portion and the test location indicated by the correction arithmetic processing unit IO. FIG. 6 shows a video signal containing information at the beginning of a high-brightness part, and (a) to (g) in FIG.
They correspond to (a) to (f) in the figure, respectively. In addition, α
are the same as those shown in FIGS. 4(C) and (d).

5(a), (b), (The shape of the high brightness part of the test screen 2A corresponding to C1 is rectangular,
The shape of the high brightness portion of the test screen 2A corresponding to FIG. 2D is circular.

FIG. 5(a) shows a case where the imaging element 5 in the package 4 is properly fixed, and the video signal in FIG. , in this case, the correction arithmetic processing unit IO corrects the test point P to a desirable one as shown by the arrow H. However, FIGS.
The shape of the high-brightness part of the test screen 2A in case 1 is the same, but this is a case where the imaging element 5 in the package 4 is not fixed correctly and is misaligned, and the high-brightness part in this case The video signal containing the information at the beginning of the sixth
As shown in Figures (bl and (C)), not only is it not possible to obtain a rise at the left end of the test portion S, but also a sufficiently steep rise cannot be obtained. In the case shown in FIGS. 5 (bl to d), the correction arithmetic processing device 10 cannot correct the desired test point P as shown by the arrow H.

The shape of the high-brightness portion of the test screen 2A is rectangular, but it is tilted from the beginning, and the video signal containing the information at the beginning of the high-brightness portion is as shown in FIG. 6(e). As shown in FIG. ) (FIG. 6(f)) is similarly corrected to a desirable test point P.

In this way, by making the shape of the high-brightness part of the test screen 2A correspond to the shape shown in FIG. The processing device 1o can correct the test location to a desirable test location P, and the test accuracy can be further improved.

In this embodiment, the correction arithmetic processing device 10 is an independent device, but it does not need to be an independent device as long as it has the same function.

Furthermore, although the test screen 2A is made up of a high-brightness portion and other portions with low brightness, if the video signal from the color imaging device 1a is obtained in the same manner as in this embodiment, this It is not limited to.

〔Effect of the invention〕

The test device for a color imaging device according to claim (1) has high brightness in the portion of the test screen corresponding to the test location of the color imaging device and its vicinity, and low brightness in the other portions. The amplitude of the signal on the color imaging device other than the test location and its vicinity can be suppressed to a small level, reducing the influence of the charge transfer structure unique to the color imaging device such as the CCD structure, and increasing the accuracy of the test. .

The test device for a color imaging device according to claim (2) has the configuration described in claim (1) and also includes a correction arithmetic processing device, so that the high-brightness portion of the test screen can be differentiated from other portions. The positional deviation of the imaging element can be corrected so that the portion corresponding to the inside of the high-brightness portion is set as the test location of the color imaging device, and the accuracy of the test can be further improved.

The test device for a color imaging device according to claim (3) has the configuration according to claim (1) or claim (2), and the shape of the high-brightness portion of the test screen is such that the test location is in the high-brightness portion. By arranging the position to correspond to the center, even if the high-brightness portion of the test screen is made small, the test location can be set as a desirable test location, and the test accuracy can be further improved.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a test device for a color image pickup device according to an embodiment of the present invention, FIG. Figures 5 and 4 are diagrams for explaining the function of the correction arithmetic processing unit, Figures 5 and 6 are diagrams for explaining the shape of the high brightness portion of the test screen, and Figure 7 is a conventional example. A configuration diagram and a partial diagram of a test device for a color imaging device,
Figure 8 is a diagram for explaining one of the causes of defective color unevenness in color imaging devices, and Figure 9 is a diagram for explaining test errors due to the effects of characteristics specific to color imaging devices such as the CCD structure. , FIG. 10 is a diagram for explaining the effect when the positional relationship between the package of the color imaging device and the imaging element is shifted. la...color imaging device, lb...optical mechanism, 2
A...Test screen, 10...Correction processing unit Figure 10XA Positive J! 'l;llj Expansion diagram (b) (d) Figure (b) Figure (a) Figure Figure (b) (c) Figure Figure

Claims (3)

[Claims] (1) A testing device for a color imaging device that focuses a test screen on the surface of an imaging element of a color imaging device via an optical mechanism, which corresponds to a test location of the color imaging device and its vicinity. A test device for a color imaging device, characterized in that a portion of the test screen has high brightness and other portions have low brightness. (2) Using the output signal of the color imaging device as input, distinguishing between the high-brightness part and other parts of the test screen, and setting the part corresponding to the inside of the high-brightness part as the test point of the color imaging device. 2. A test device for a color image pickup device according to claim 1, further comprising a correction arithmetic processing unit for correcting a positional deviation of an image pickup element. (3) The color imaging device according to claim (1) or claim (2), wherein the shape of the high brightness portion of the test screen is such that the test location is located at a position corresponding to the center of the high brightness portion. Test equipment.