JPH06153011A - Focus measuring method - Google Patents

Abstract

PURPOSE:To satisfactorily adjust a focus with simple work by obtaining focus measuring data by the detection signal of a CCD line sensor and slightly shifting the focus of a rod array lens. CONSTITUTION:A central control unit 11 controls a measuring video signal generator 12, generates a cross-hatching signal for focus adjustment and displays a cross-hatching picture 14 in the tube surface of an image receiver 13. The CCD line sensor 15 to which a multi-lens array 16 is fitted is adhered to the pipe surface in such a state, and the vertical line and the lateral line of a bright line in the picture 14 is detected. At that time, the focus of the array 16 is slightly shifted from the pipe surface. The sensor 15 reads signal charges accumulated in respective light-receiving parts and supplies them to a beam size measuring unit 17 as detection signals. The unit 17 measures the horizontal width Hw of the vertical line and the vertical width Vw of the lateral line and transfers them to the unit 11. The unit 11 rotates a step motor 19 so that the widths Hw and Vw become minimum so as to automatically adjust the focus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus measuring method for a television receiver or a monitor receiver using a cathode ray tube.

[0002]

2. Description of the Related Art A television receiver using a cathode ray tube must be focused on the electron beam so that the image displayed on the surface of the cathode ray tube will be good before it is manufactured and shipped from the factory. It is necessary to go and adjust to the proper condition. This conventional focus measurement is performed, for example, as shown in FIG. That is, as the television receiver 1, the volume 3 for adjusting the focus of the electron beam of the cathode ray tube 2 is exposed, and the mirror 4 is placed so as to face the front surface 1a of the television receiver 1. The image displayed on the cathode ray tube 2 of No. 1 is reflected by this mirror 4 to be confirmed by the coordinator m on the back side of the television receiver 1. In this state, the adjuster m operates the focus adjusting volume 3 to judge the degree of focus of the image viewed through the mirror 4 and adjust so that a good image is displayed.

[0003]

However, in such an adjusting method, since the adjuster makes a judgment by directly looking at the image, the accuracy of focus adjustment is determined by the judgment of the adjuster, and the accuracy is likely to be non-uniform. was there.

For this reason, various attempts have been made to automate the focus measurement by detecting the displayed image with a sensor, but it is difficult to perform accurate beam width measurement quickly with a simple device. It was

An object of the present invention is to make it possible to adjust the focus of a television receiver of this type in a satisfactory manner with a simple operation.

[0006]

SUMMARY OF THE INVENTION The present invention provides a method for measuring the focus of an image displayed on the tube surface of a cathode ray tube by displaying an image 14 displayed on the tube surface of a receiver 13 as shown in FIG. The CCD line sensor 15 detects the CCD line sensor 1 through the rod array lens 16.
The focus measurement data is obtained from the signal detected at 5, and the focus of the rod array lens 16 is slightly shifted from the tube surface.

In this case, the tube surface of the cathode ray tube is made to emit light in a single color.

Further, in this case, the focus control data of the receiver is changed by using the measurement data.

[0009]

According to the present invention, since the image of the tube surface is detected by the CCD line sensor through the rod array lens which is slightly out of focus, the light energy accumulated in the CCD line sensor is close to the actual beam shape. Therefore, good focus measurement can be performed.

In this case, accurate focus measurement can be performed by causing the tube surface of the cathode ray tube to emit light of a single color suitable for focus measurement.

Further, by changing the focus control data of the receiver using the measurement data, the focus adjustment of the receiver can be favorably performed with a simple structure.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a diagram showing a system configuration to which the measuring method of this embodiment is applied. In the figure, 11 is a central control unit (CPU) composed of a computer, 12 is a measuring video signal generator, and 13 is a receiver. Television receiver, which is a measured object, 14
Is a cross-hatch image displayed on the television receiver 13, 15 is a CCD line sensor for detecting an image displayed on the screen of the television receiver 13, and 16 is the C line
A multi-lens array arranged between the CD line sensor 15 and the tube surface of the television receiver 13, 17 is a beam size measuring unit, 18 is a bit insertion robot, 19 is a step motor, and 20 is a focus adjustment volume.

The television receiver 1 having the configuration shown in FIG.
Cross hatch image 14 displayed on the surface of the cathode ray tube of No. 3
The following describes the state in which the focus adjustment is performed by performing the measurement of the above. First, the central control unit 11 controls the measurement video signal generator 12 to generate a focus adjustment crosshatch signal equivalent to the monoscope signal, and then the television. The image is supplied to the receiver 13, and the crosshatch image 14 is displayed on the tube surface of the television receiver 13. As shown in FIG. 3, for example, the cross-hatched image 14 is black only in the vicinity detected by the sensor, bright lines are displayed vertically and horizontally in the black background, and the other parts are gray. Then, in this example, the vertical and horizontal bright lines are made green, and the bright lines are displayed only by the beam that causes the green phosphor to emit light.

In this state, the CCD line sensor 15 to which the multi-lens array 16 is attached is brought into close contact with the tube surface of the television receiver 13, and the vertical and horizontal lines of the bright lines in the displayed crosshatch image 14 are detected. Let At this time, the focus of each lens forming the multi-lens array 16 is slightly shifted from the tube surface of the cathode ray tube. That is, as shown in FIG. 2, the multi-lens array 16 is configured by arranging cylindrical microlenses 16a in a straight line,
The microlenses 1 function as an optical relay member that causes the image displayed on the tube surface 13a of the television receiver 13 to enter the CCD line sensor 15.
The adjustment state of the focus with respect to the tube surface 13a of
Focus on a position slightly deviated from 3a.

The CCD line sensor 15 is a sensor in which the light receiving portions are linearly arranged, and reads out the signal charge accumulated in each light receiving portion and supplies it to the beam size measuring unit 17 as a detection signal. Then, the beam size measuring unit 17 measures the horizontal width H _W of the vertical line and the vertical width V _W of the horizontal line from the detection signal. As the measurement processing in this case, the detection signal supplied to the beam size measurement unit 17 is compared with the reference level after cutting the high frequency component by the low pass filter, and the width H _W and Measure V _W. Then, the measured widths H _W and V _W are transferred to the central controller 11. The beam size measuring unit 17 is a CC
Measuring video signal generator 12 equipped with D driver
Generates CCD drive pulse by receiving the synchronization signal from
The CD line sensor 15 is driven.

As shown in FIG. 4, the positional relationship between the CCD line sensor 15 and the multi-lens array 16 with respect to the crosshatch image 14 is set to be oblique with respect to the vertical and horizontal lines of the bright lines of the crosshatch image 14. ,Vertical line,
The horizontal lines are set to cross each other, and the horizontal width H _W and the horizontal width V _W are detected by comparing the sensor output with the reference level TH, as shown in FIG.

On the side of the central controller 11,
Width H indicated by the data_WAnd V _WSo that
Rotate the step motor 19 to automatically focus
To adjust. That is, the central control unit 11 uses the bit insertion
The bot 18 is controlled so that the tip of the step motor 19 is
The focus adjustment volume of the television receiver 13.
It is automatically inserted into the frame 20 and rotated by the step motor 19.
The focus adjustment volume 20 is driven and controlled.

The television receiver 13 used for focus adjustment of this example uses a color selection mechanism called an aperture grill as a cathode ray tube.
As shown in FIG. 5, the phosphors of red R, green G, and blue B are sequentially formed in a vertical shape, and each of the red R, green G, and blue B phosphors forms one pitch. ing. Since the crosshatch image 14 used in the focus adjustment of this example emits only the green phosphor, when the beam shape is as shown in FIG. 6B, the detected brightness is As shown in FIG. 6C, this is the level when the beam of this shape crosses the green phosphor.

By thus performing the focus measurement and adjusting the focus of the television receiver 13, accurate focus measurement can be performed quickly and easily. That is, in this example, the cross hatch image 14 displayed on the tube surface 13a of the television receiver 13 is transferred to the CCD line sensor 15 via the multi-lens array 16 out of focus.
Since it is read with, the level close to the actual beam shape without the influence of the aperture grille is detected.

This will be described with reference to FIG. 7. When the focus of the multi-lens array 16 exactly matches the tube surface, as shown in FIG. 7A, the green phosphor emits light. Only the detected portion detects the corresponding level, but in the case of this example, the light energy at each detection point is diffused due to the out of focus, as shown in B of FIG. . Therefore, the light energy accumulated in the CCD line sensor 15 is an accumulation of the diffused light energy as shown in C of FIG. 7, and the high-pass component is removed from the output of the CCD line sensor 15 by the low-pass filter. By comparing the signal (D in FIG. 7) with the reference level (dashed line), a detection pulse having a beam width shown in E in FIG. 7 is obtained.
Then, the focus is properly adjusted by adjusting the focus of the television receiver 13 so that the beam width measured in this way becomes the minimum.

The adjustment work by such a measurement is simple and quick because the pulse width is simply minimized. In particular, the detection output of the CCD line sensor 15 is not affected by the color selection mechanism (aperture grill etc.) included in the cathode ray tube of the television receiver 13,
The bright line width of the crosshatch image 14 displayed on the tube surface can be made relatively wide, and good measurement can be performed. Further, the system of this example enables real-time measurement.

In the above-described embodiment, the focus adjustment volume 20 of the television receiver 13 is rotated for adjustment, but the adjusted television receiver has a memory for storing the focus control value. , If the focus control is performed on the basis of the control data stored in this memory, the control data of this memory only needs to be rewritten based on the measured data, and the configuration for adjustment is It will be easier.

Further, the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various other structures can be adopted.

[0025]

According to the present invention, since the image of the tube surface is detected by the CCD line sensor through the rod array lens which is slightly out of focus, the light energy accumulated in the CCD line sensor is close to the actual beam shape. This makes it possible to perform better focus measurement than a display image with a wide bright line width.

In this case, by making the tube surface of the cathode ray tube emit light of a single color suitable for focus measurement, more accurate focus measurement can be performed.

Further, by changing the focus control data of the receiver using the measurement data, the focus adjustment of the receiver can be favorably performed with a simple structure.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a measuring state of a tube surface according to an embodiment.

FIG. 3 is an explanatory diagram showing a display image during measurement according to an example.

FIG. 4 is an explanatory diagram showing an arrangement state of sensors according to an embodiment.

FIG. 5 is a characteristic diagram showing a sensor output according to an embodiment.

FIG. 6 is a waveform diagram showing a beam detection state according to an embodiment.

FIG. 7 is a waveform diagram showing a focus measurement state of an example.

FIG. 8 is a configuration diagram showing an example of a conventional focus adjustment method.

[Explanation of symbols]

 11 Central Control Unit 12 Video Signal Generator for Measurement 13 Television Receiver 14 Crosshatch Image 15 CCD Line Sensor 16 Multi-lens Array 17 Beam Size Measuring Unit 18 Bit Insert Robot 19 Step Motor 20 Focus Adjustment Volume

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[Procedure amendment]

[Submission date] December 15, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006]

SUMMARY OF THE INVENTION The present invention provides a method for measuring the focus of an image displayed on the tube surface of a cathode ray tube by displaying an image 14 displayed on the tube surface of a receiver 13 as shown in FIG. The CCD line sensor 15 detects the CCD line sensor 1 through the rod array lens 16.
Focus measurement data is obtained from the signal detected in 5 .
Also affected by the color selection mechanism (aperture grill etc.)
In order to make it difficult, the beam width of the image 14 is widened and the focus of the rod array lens 16 is slightly shifted from the tube surface.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

Adjusting the focus of R, G and B three colors
Therefore, the surface of the cathode ray tube is made to emit light in a single color.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

[0009]

According to the present invention, the beam width of the crosshatch (brightness
Since focus to widen the line width) to detect the image of the tube surface in the CCD line sensor through a slight shift rod array lens, the light energy accumulated in the CCD line sensor is A
It is not easily affected by the perch grill, etc., and the one close to the actual beam shape can be detected in one field, and good focus measurement can be performed.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

The television receiver 1 having the configuration shown in FIG.
Cross hatch image 14 displayed on the surface of the cathode ray tube of No. 3
The following describes the state in which the focus adjustment is performed by performing the measurement of the above. First, the central control unit 11 controls the measurement video signal generator 12 to generate a focus adjustment crosshatch signal equivalent to the monoscope signal, and then the television. The image is supplied to the receiver 13, and the crosshatch image 14 is displayed on the tube surface of the television receiver 13. For example, as shown in FIG. 3, the cross-hatched image 14 is black only in the vicinity detected by the sensor, bright lines are displayed vertically and horizontally in the black background, and the other parts are gray. This Gre
Equivalent to a monoscope signal by changing the brightness level of the b part
To Then, in this example, the vertical and horizontal bright lines are made green, and the bright lines are displayed only by the beam that causes the green phosphor to emit light. It should be noted that except for such single color focus adjustment
It may be adjusted as well. For example, when using 3 color leaflets, R,
Switch between G and B. In CTV, adjust with the white bright line.
You may do it.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction content]

The television receiver 13 used for focus adjustment of this example uses a color selection mechanism called an aperture grill as a cathode ray tube.
As shown in FIG. 5, the phosphors of red R, green G, and blue B are sequentially formed in a vertical shape, and each of the red R, green G, and blue B phosphors forms one pitch. ing. Beam width of cross hatch image 14 used for focus adjustment
When the (bright line width) is illuminated by only one dot and only the green phosphor is made to emit light, for example, when the beam shape is as shown in FIG. 6B, the detected luminance is shown in FIG. 6C. As shown, this is the level when the beam of this shape crosses the green phosphor. And in this example,
Scan 2 pitches continuously with the pitch of the system illuminated 1 pitch.
It This is equivalent to widening the bright line width. That is, in FIG.
Scanning 1 pitch as shown in AB shows CCD line
The light energy accumulated in the in-sensor 15 is shown in C of FIG.
(The position marked G in these figures)
Is the position of the green phosphor). And further, B of FIG.
1 pitch scan from the state shown in Fig. 9 as shown in Fig. 9D.
Then, the optical energy accumulated in the CCD line sensor 15
Gee is as shown in E of Fig. 9, and the accumulated error of both scans
The energy shown in F of FIG. 9 which is the sum of the energy is the final
Therefore, it is accumulated in the CCD line sensor 15. This
The energy distribution of is close to the actual beam shape. This bee
The frame detection is performed within one frame.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

The adjustment work by such a measurement is simple and quick because the pulse width is simply minimized. In particular, the detection output of the CCD line sensor 15 is not affected by the color selection mechanism (aperture grill etc.) included in the cathode ray tube of the television receiver 13,
Good measurement is possible. Further, the system of this example enables real-time measurement.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction content]

It should be noted that the number of measurement points should be increased to
It is possible to take a lance. Further, the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various other configurations can be adopted.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

[0025]

According to the present invention, a cloth having a wide emission line width
Since the image of the tube surface is detected by the CCD line sensor through the rod array lens that is slightly out of focus from the hatch signal, the light energy accumulated in the CCD line sensor will be close to the actual beam shape, and good focus will be achieved. Can measure.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a measuring state of a tube surface according to an embodiment.

FIG. 3 is an explanatory diagram showing a display image during measurement according to an example.

FIG. 4 is an explanatory diagram showing an arrangement state of sensors according to an embodiment.

FIG. 5 is a characteristic diagram showing a sensor output according to an embodiment.

FIG. 6 is a waveform diagram showing a beam detection state according to an embodiment.

FIG. 7 is a waveform diagram showing a focus measurement state of an example.

FIG. 8 is a configuration diagram showing an example of a conventional focus adjustment method.

FIG. 9 is an explanatory diagram showing a scan state.

[Explanation of Codes] 11 Central Control Unit 12 Video Signal Generator for Measurement 13 Television Receiver 14 Crosshatch Image 15 CCD Line Sensor 16 Multi-lens Array 17 Beam Size Measuring Unit 18 Bit Insert Robot 19 Step Motor 20 Focus Adjustment Volume

[Procedure Amendment 11]

[Document name to be corrected] Drawing

[Correction target item name] Figure 9

[Correction method] Added

[Correction content]

[Figure 9]

Claims (3)

[Claims] 1. A focus measuring method of an image displayed on a tube surface of a cathode ray tube, wherein an image displayed on the tube surface is detected by a CCD line sensor via a rod array lens and detected by the CCD line sensor. A focus measurement method in which focus measurement data is obtained from the generated signal and the focus of the rod array lens is slightly shifted from the tube surface. 2. The focus measuring method according to claim 1, wherein the tube surface of the cathode ray tube is made to emit light in a single color. 3. The focus measuring method according to claim 1, wherein the focus control data of the receiver is changed using the measurement data.