JPS59117885A - Registration adjusting device of image pickup device - Google Patents

Abstract

PURPOSE:To attain highly accurate adjustment of shift in registration of the entire screen by changing the amount of centering control of a deflection system of an image pickup tube depending on the registration shift data detected newly. CONSTITUTION:Lots of detecting marks over the entire screen of a test chart are picked up respectively by plural image pickup tubes 54-56, and data of vertical and horizontal registration shift are detected by a registration shift circuit 60 at each mark. The data of registration shift at a region other than each mark is obtained by an arithmetic circuit 63 through interpolation at the same time. The data of registration shift is applied to deflection coils 541- 561 in synchronizing with the electron beam scanning of the image pickup tubes 54-56 as the centering control amount. Further, the control amount is changed depending on the registration shift data detected newly, then the registration of the entire screen is adjusted with high accuracy.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to an imaging device using a plurality of image pickup tubes, such as a color television camera (hereinafter referred to as a color TV camera).
The present invention relates to a registration adjustment device.

[Technical background of the invention and its melting point]

As is well known, in a color TV camera using a plurality of image pickup tubes, an automatic adjustment method under program control using a microcomputer has already been established for mutual registration adjustment of the image pickup tubes. This automatic adjustment method can be classified into several methods, but the principle is the same. For example, as shown in FIG. 1, a test chart is imaged, and a video signal corresponding to the detection arcs 11 and 12, which are generated when a horizontal scanning line scans the detection marks 11 and 12 on the screen, is filtered through a bandpass filter or high-frequency filter. Registration deviations in both the horizontal and vertical directions are detected by detecting the phase difference between the output video signals of each image pickup tube using a bandpass filter or the like. Then, the deflection circuit is controlled by a program determined to minimize these registration deviations, and adjustments are made so that the registration deviations are minimized.

In the above automatic adjustment, the adjustment items are horizontal.

Centering, size in each vertical deflection.

It has linearity, skew distortion correction, and rotation correction. The first reason why the adjustment items are limited in this way is that the above items follow the control items that were used when manual adjustment was performed before automatic adjustment, and the second reason is that these items are horizontal.

For vertical image deflection, centering, size, and linearity correction can be performed by controlling the DC bias, amplitude, and linearity of the sawtooth wave current flowing through the deflection coil, which can be easily realized using circuit technology from the manual era. (Skew correction and rotation correction have already been put into practical use since the era of manual adjustment.) For these reasons, the automatic adjustment items are easy to implement and are now computerized, but they are still the subject of control in the same way as in the era of manual adjustment. It is said that

However, with these adjustment items, it is difficult to perform highly accurate registration adjustment over the entire screen. For example, considering one horizontal scanning line at the center of the screen, in the case of FIG. 1, there are three detection marks - centering.

By controlling the size and linearity in three terms, it is possible to achieve the best registration only at three detection points. Therefore, on this -horizontal scanning line, the phases of the output video signals of the image pickup tubes can be matched only at three points.

However, on other scanning lines, for example on the upper and lower scanning lines of the screen, there may be only one detection point in the horizontal scanning direction.
Or not at all. For this reason, registration adjustment is performed by skew correction in such areas, but it is clear that the registration accuracy deteriorates in the periphery of the screen. Further, the same problem as the horizontal registration occurs also in vertical registration adjustment.

Incidentally, a method for detecting misregistration of many points in the horizontal and vertical directions over the entire screen has been proposed and put into practical use.

FIG. 2 shows a test chart used in this method. In this way, the same detection mark 2 is displayed on the entire screen.
In a chart with a total of 25 1's arranged in 5 rows and 5 columns,
Horizontal and vertical misregistration of these 25 points can be detected. Therefore, with this method, by increasing the number of detection T-types 21, registration deviations can be detected at many points on the screen.

However, what is performed in the chart as exemplified in FIG. 2 is registration shift detection, and no correction is currently performed. Therefore, although it is possible to evaluate the registration of a color TV camera, it has not been possible to adjust it to the best accuracy.

[Purpose of the invention]

This invention was made based on the above circumstances, and its purpose is to adjust the registration deviation of the entire screen with higher precision than the conventional centering, size, linearity, skew, and rotation corrections. It is an object of the present invention to provide a registration adjustment device for an imaging device that is possible.

[Summary of the invention]

This invention images a large number of detection marks over the entire screen using a plurality of image pickup tubes, detects horizontal and vertical registration deviation data for each of the imaged marks, and detects registration deviation data in areas other than each mark. The registration deviation data is obtained by interpolation, and this registration deviation data is supplied as a centering control amount to the deflection system of the image pickup tube in synchronization with the electron beam scanning of the image pickup tube. This is intended to adjust the registration of the entire screen with high precision by changing the registration according to the registration deviation data.

[Embodiments of the invention]

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

First, the principle of this invention will be explained. A typical color TV camera system that uses multiple image pickup tubes captures images in red, green, and blue (hereinafter referred to as R and G).

This is a three-tube system in which the image is separated into three primary colors (denoted as B) and an image pickup tube is used for each primary color. In this method, the R and H registrations are adjusted based on the video signal output from the G image pickup tube, which has spectral characteristics most similar to human visual sensitivity. Furthermore, it is well known that G is compared with a reference signal, such as a signal commonly called a grating signal or a crosshatch signal, to set the polarization distortion of G to the best adjustment state.

Figure @2 shows an example of a test chart applied to this invention, in the horizontal direction (H) of the screen.

25 identical dot-like detection marks 2, 5 each on the vertical diagonal
1 are arranged.

With respect to the detection mark 21 of the test chart, R and H horizontal and vertical registration deviations are detected using G as a reference. This detection means is similar to known technology. This detection results in horizontal lines corresponding to 25 detection marks 21 on the screen.

Registration shifts in both vertical directions are required. Furthermore, since the deviations of R and B with respect to G are basically the same,
The deviation of R with respect to G will be explained below.

FIG. 3 shows a registration deviation detection point 31 corresponding to the detection mark 2 shown in FIG.

FIG. 4 shows the mere registration deviation with respect to G detected at this detection point 31. For example, with G as the reference, the delay of R is positive (vertical axis upward) and the advance is negative (vertical axis downward). It shows. Further, dotted lines connect the screens vertically, and dashed lines connect the screens horizontally. Therefore, the surface formed by the 16 quadrilaterals formed by the dotted line and the dashed-dotted line represents the horizontal registration shift in the entire screen. In addition, FIG. 4 shows the 25 detection points 31 in FIG. 3 interconnected. If the number of detection points 31 shown in FIG. 3 is increased both horizontally and vertically, the plane shown in FIG. 4 can be more accurately registered in the horizontal direction. This represents the deviation.

By the way, each surface shown in FIG. 4 is an arbitrary point 70 horizontal (2) L on the screen determined both horizontally and vertically.
/92) Since this represents a range 5 error, if the horizontal registration error shown in FIG. 4 is caused in the opposite direction, the horizontal alignment error can be corrected for the entire screen. In other words, since the horizontal registration y deviation of R with respect to G at any point on the screen can be considered as the deviation of the horizontal centering at this arbitrary point, the centering at this arbitrary point is changed in the opposite direction by an amount equal to the deviation. By shifting the position, the registration deviation at this arbitrary point can be corrected. In other words, since the horizontal misregistration shown in Figure 4 is caused by the registration of R with respect to G, it is only necessary to shift the centering of R by the amount represented by the plane in Figure 4 depending on the position on the screen. It turns out.

For example, in the case of an electromagnetic deflection type image pickup tube, it is sufficient to generate a centering magnetic field in the deflection magnetic field to correct misregistration in synchronization with the horizontal and vertical image deflection;
In the case of a D-fuze, it is sufficient to generate a centering electric field to correct the misregistration.

Next, an embodiment of the present invention based on the above principle will be described.

In FIG. 5, a test chart 51 has a configuration similar to that shown in FIG. This test chart 51 is passed through a lens system 522 and a color separation optical system 53 to R, G, and H image pickup tubes 54 and 55.

The image is focused on 56 targets. Each image pickup tube 54.5
5.56 respectively have deflection coils 54. .

551.56□ is provided. Each image pickup tube 54.
The video signals outputted from R video circuits 55 and 56 are respectively sent to R video circuits 57. G video circuit 58. is supplied to the B video circuit 59,
Each video signal input to these video circuits 57 to 59 is amplified and subjected to predetermined processing. The output video signals of these video circuits 97 to 59 are supplied to a color signal synthesizer (not shown) and also to a registration deviation detection circuit (hereinafter referred to as registration deviation detection circuit) eo. This registration deviation detection circuit 60 is comprised of a well-known circuit for detecting all registration deviations, an A/D converter, and the like. When an automatic adjustment command signal is supplied from an input terminal 64 to an arithmetic circuit 63 (described later), this registration deviation detection circuit 60 detects the difference between the R and B video signals relative to the G video signal for each detection mark 31 shown in FIG. It detects displacement in the horizontal and vertical directions, and this is output as a digital signal.

This detected misregistration data is supplied to the memory 62 via the write circuit 61.

Hereinafter, in order to simplify the explanation, the horizontal direction registration of R with respect to G will be explained as an example. As described above, the registration deviation data of the R video signal with respect to the GO video signal detected by the registration deviation detection circuit 60 is expressed as shown in the diagram $4. When writing such data to the memory 62, the following method is used. That is, the storage area of the memory 62 is arranged in such a way that vertical scanning lines are arranged in rows, and the horizontal scanning direction is divided into time slots corresponding to an integer of the horizontal scanning period, and the order starts from the start of the horizontal scanning. is considered to be a column.

Further, in the registration deviation detection circuit 60, a code corresponding to the position of the detection mark is added to the registration deviation data corresponding to each detection mark. For example, if the detected data is H direction 1 shown in Figure 3,
In direction 1, if it is a horizontal misregistration of R with respect to G, Hl , Vl , RG , HREG
It is structured as I. The write circuit 61 determines this code, and in this case, the memory 62 stores the horizontal registration deviation of R with respect to G.
, and stores the misregistration data at the h 1 and vl addresses of this area. In this way, 25 pieces of data are stored in the memory 62 as shown in FIG. In addition, in FIG. 6, addresses hl and vl are expressed as All.

On the other hand, when registration deviation detection is completed for all 25 detection marks, the registration deviation detection circuit 60 supplies a completion signal to the arithmetic circuit 63. This arithmetic circuit 63 is constituted by, for example, a microcomputer, and has arithmetic, judgment, and storage functions. When the completion signal is supplied to this arithmetic circuit 63, the write circuit 61 waits for the final detection data to be written into the memory 62, and then all or part of the 25 pieces of data stored in the memory 62 are read out. be caught. Then, using this data, the registration deviation in areas other than the detection mark is interpolated. That is, the data shown in FIG. 4 are arranged in the upper row from left to a1□2a82 to a13. The second line is a21t'
22-a26. Similarly, the bottom row a31゜a5! ~a6
11, and these addresses are respectively A fl ”
Ale r A! 1-A2. ...A5. %A, 11
Then, as shown in Figure 7, < Alt r Alt +
At□.

The inner data surrounded by the address of A22 are these four data aIly '12. '21y' can be interpolated from 2□.In other words, if the number of scanning lines between A11 and A2□ is N, the contents of all addresses between A1□ and All are data all and &21. can be interpolated by directly connecting line segments.Similarly, the contents of the addresses between Ast and A2□ can also be found from a□2 and a2.In addition, in the horizontal direction, there are M addresses from All to A12. Assuming that f, the contents of all addresses between A11 and A21 can be interpolated from a□1raX!.Similarly, the contents of addresses from A. to A22 can also be interpolated.Therefore, ' 11 ”21y'1
2 ”22 t all ”12 r ”21 ”22
From the four line segments of A11 t Al1 t A21 +
A2! All the contents of the addresses surrounded by can be interpolated, and similarly, all the data corresponding to addresses in the plane containing 25 detection marks can be interpolated. Furthermore, the seventh detection mark is also applied to the area outside the 25 detection marks.
It is clear that interpolation is possible by extending each line segment, as shown by the dotted arrows in the figure. In this way, the arithmetic circuit 63
Registration deviation data in areas other than the detection area obtained in the above are stored at predetermined addresses in the memory 620 (A1-A16, A21''-A shown in FIG. 6).
2B...Addresses other than A51 to A611).

As described above, when the detected data and interpolated data are stored in the memory 62, the arithmetic circuit 63
A read command signal is supplied to the read control circuit 65. This readout control circuit 65 generates a readout control signal based on vertical and horizontal synchronizing signals supplied from an input terminal 66, and this readout control signal is transmitted to the readout circuit 6.
7. This readout circuit 67 reads out the data in the memory 62 in synchronization with the electron beam scanning of the image pickup tube according to the readout control signal, and the readout data is sent to a digital/analog (D/A) converter. 68 and converted into an analog signal. The signal output from this D/A converter 68 is a signal proportional to the amount of horizontal registration deviation of the point scanned by the electron beam of the image pickup tube with respect to G of R, and this signal is, for example, a signal in four quadrants. The multiplier is supplied to the R deflection circuit 70 via an attenuator 69 consisting of a digital attenuator capable of performing an arithmetic operation. This R deflection circuit 70 and G deflection circuit 71
．． The B deflection circuits 72 generate horizontal and vertical deflection signals in response to synchronization signals supplied to input terminals 73, respectively, and these deflection signals are supplied to the deflection coils 54, 561 of the image pickup tubes 54 to 56. be done. Further, in the R deflection circuit 70, a deflection signal is generated to generate a deflection magnetic field in a direction to correct the R horizontal registration shift. Such a deflection signal can be generated by, for example, multiplying the horizontal centering current by 1 volt of the output of a voltage-to-current conversion circuit that converts the signal output from the n/A converter 68 into a full current waveform. In this case, it is necessary that the frequency characteristics of the circuit system including the horizontal deflection coil extend to a sufficiently high range.
The frequency characteristics of the circuit system in Japanese Patent Application No. Sho 56-133364 filed by the applicant of the present application are favorable and favorable.

The above operation is performed in steps 81 to 8 of the flowchart shown in FIG.
Up to 6. In this way, data stored in the memory 62 is read out and R is converted based on the D/A i-converted signal.
When the horizontal centering is completely corrected, it is possible to generate a magnetic field in the direction to correct the misregistration as described above, but the amount of correction cannot be detected. Then, the registration deviation data is again detected by the registration deviation detection circuit 60 from the video signal of the detection mark 21 on the test chart 5 obtained by the deflection magnetic field corrected in this way. These detected data are respectively "'11~"'15 "'"'5
1 to a'as, these values are a'ij "" IL i j / e ・・
・・・・・・・・・・・・(1) or a A3--c φa I J""・"-Roken (2)
becomes. In the case of Equation (1), the registration deviation after correction is reduced, and in the case of Equation (2), the direction of deviation is reversed due to excessive correction, for example, the deviation in the advancing direction becomes a lag direction. Indicates the condition.

The arithmetic circuit 63 determines whether the corrected data detected by the registration deviation detection circuit 6Q is below a tolerance value, and if the correction is small, a signal is generated to reduce the attenuation amount of the attenuator 69. . First, if the correction is large, a signal is generated that increases the amount of attenuation of the attenuator 69, and this signal is supplied to the attenuator 69. Therefore, this attenuator 6
9, the output signal of the D/A converter 68 is multiplied by the generated signal, and the R deflection circuit 70 generates a deflection magnetic field according to this value.

This operation (steps 87 to 89 shown in FIG. 8) is repeated until the registration deviation data becomes less than or equal to the allowable value, and the adjustment is completed when the registration error data becomes less than or equal to the allowable value.

Although the horizontal misregistration of R with respect to G has been explained above, it is clear that the vertical misregistration can also be corrected by the same means, and the horizontal and vertical misregistration of B with respect to G can be corrected. is also possible. Further, the same applies to correcting the G deflection distortion with respect to the reference electric signal.

According to the above embodiment, the registration deviation data of the entire screen is grasped by the registration deviation data corresponding to many detection points over the entire screen and the registration deviation data obtained by interpolating the points other than the detection points. Based on the data, registration errors are corrected as centering errors in the horizontal and vertical directions in the entire screen area. Therefore, unlike the conventional method, there is no problem of the correlation between centering, size, and linearity, that is, changing the linearity causes a change in centering or size, and it is extremely easy and highly accurate to correct the C registration shift. can be corrected.

Further, in correction of registration deviation, a centering magnetic field for correction is generated by decreasing or increasing detected registration deviation data using a subtractor 69. Therefore, the conventional method is horizontal.

6 items for vertical centering, size, and linearity,
Then, 2 items of skew and rotation are added, and 8 items of control are corrected using 8 attenuators or multipliers at 3 locations on the horizontal and vertical center lines of the screen (6 locations in total).
Compared to other areas that depend on the coil assembly and registration characteristics unique to the image pickup tube, this invention does not require many control items such as centering, size, linearity, skew, and rotation, and only one attenuation The horizontal or vertical registration can be corrected over the entire screen using a device, and the registration can be adjusted over the entire screen using two attenuators for horizontal and vertical, which improves adjustment accuracy and reduces the need for attenuators, etc. It is possible to obtain effects such as simplifying the circuit configuration and improving stability.

Note that this invention is not limited to the above embodiments.

That is, the test chart is not limited to the chart shown in FIG. 2, but other shapes can also be used as long as measurements can be taken at many locations on the screen.

Also, since the standard television system uses interlaced scanning, the first. 1 from the second two fields
The frame is configured.

Therefore, detection of misregistration is the first step. The detection may be specified in either one of the second fields, or the detection may be performed the same number of times in both fields, and the average value may be calculated.

Furthermore, although the amount of attenuation of the attenuator 69 is automatically adjusted, it is also possible to adjust it manually.

That is, after detection of registration deviation and completion of data interpolation calculation, if a registration chart or the like is imaged and the amount of attenuation of the attenuator 69 is manually changed, the horizontal registration deviation of R to G can be detected while visually observing the entire video monitor. Can be adjusted. When this manual adjustment is performed for 5 seconds, the conventional 8-item adjuster is reduced to 2 items, and there is no correlation between them, so it is level.

It has the advantage that adjustment can be easily performed, such as vertical registration deviation adjustment can be performed independently.

It goes without saying that various other modifications can be made without departing from the gist of the invention.

〔Effect of the invention〕

As detailed above, according to the present invention, the registration adjustment of an imaging device is capable of adjusting the registration deviation of the entire screen with higher precision than conventional centering, size, linearity, skew correction, and rotation correction. equipment can be provided.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a conventional registration automatic adjustment chart, FIG. 2 is a diagram showing an example of a registration automatic adjustment chart applied to the present invention, and FIG.
Figures 4 and 4 are diagrams shown for detailed explanation of the present invention, Figure 5 is a configuration diagram showing an embodiment of the registration adjustment device for an imaging device according to the present invention, and Figures 6 to 8 are are diagrams shown for explaining the operation of FIG. 5, respectively. 51...Test chart, 54.55.56...Image tube, 54. ．． 55j, 56. ...Deflection coil, 60
...Shin shift detection circuit, 62...Memory, 63...
- Arithmetic circuit, 65... Readout control circuit, 69... Attenuator, 70... R deflection circuit, 7... G deflection circuit,
72...B deflection circuit. Applicant's Representative Patent Attorney Takehiko Suzue Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] A plurality of image pickup tubes capture images of a large number of detection marks over the entire screen, and a means for detecting horizontal and vertical registration deviation data for each of the large number of marks, and a memory in which this data is stored at addresses corresponding to the detection marks. a means for interpolating registration deviation data in areas other than the detection mark from the stored data and storing the interpolated data in a corresponding atto of the memory; and a means for interpolating registration deviation data in areas other than the detection mark from the stored data, means for reading data and interpolated data in synchronization with the electron beam sweep of the image pickup tube, and a deflection system of the image pickup tube that is supplied with the read data and uses the data as control variables in the horizontal and vertical directions. means for supplying said control at
A registration adjustment device for an imaging device, comprising: means for varying the amount of control based on registration deviation data detected from a video signal of an image pickup tube adjusted according to.