JP2000186921A - Beam shape measuring method for cathode-ray tube and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the shape of an electron beam on a phosphor of a mounted cathode-ray tube in an image display device. SOLUTION: This beam shape measuring device comprises a photometric sensor 6C, disposed on an outer face of a panel part of a cathode-ray tube 1, for detecting light emission of a phosphor constituting a fluorescent screen to generate an electric signal, a photometric part 6 having at least a pinhole 6BA which is disposed on the light incident side of the photometric sensor 6C and through which light emitted from a point of the phosphor is incident to the photometric sensor 6, an operation part 3 having at least a signal generator 3D and a deflection circuit 3C, a data processing part 7 for calculating brightness value according to the output signal from the photometric sensor 6C, a frame memory 5 for storing the processed brightness data by the data processing part 7, and a main control part 4 for controlling the operation of each part. The signal generator 3D generates both a direct current with which a deflecting coil of a deflector 2 shifts an electron beam to a prescribed position of the fluorescent screen and a step current with which the deflecting coil sequentially slightly deflects the electron beam with the shifted position as a reference in a scan direction according to a pulse width of a cathode current, and the deflection circuit 3C applies the direct current and the step current generated by the signal generator 3D to the coil of the deflector 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for measuring the shape of an electron beam of a cathode ray tube, and more particularly to a technique for measuring the shape of a spot of an electron beam resting on a phosphor screen, based on the result of measurement. The present invention relates to a method and apparatus for measuring a beam shape of a cathode ray tube which approximates a dynamic electron beam spot shape visible to the eye.

[0002]

2. Description of the Related Art Quantitative measurement of the shape of an electron beam of a cathode ray tube is roughly classified into three types. The first method is to shift an electron beam to an arbitrary position on a phosphor screen, move the electron beam by a small distance in the horizontal or vertical direction from that position, and use a photoelectric conversion element with a pinhole for each minute portion to shift the electron beam. This is a method of measuring the light emission luminance of each pixel and complementing the luminance between the measurement positions.

A second method is to shift the electron beam to an arbitrary position on the phosphor screen and measure the luminance distribution once using a photoelectric conversion element such as a TV camera. In this method, the luminance distribution in the scanning state of the cathode ray tube mounted on the display device is measured at once by a photoelectric conversion element such as a TV camera.

In the first method, high-precision measurement is possible by using a photoelectric element having a wide dynamic range such as a photomultiplier. However, the dynamic luminance distribution in a scanning state such as when mounted on an image display device makes it difficult to accurately measure the high-speed pulse-like cathode current and the reproducibility of the position of the light emitting unit. The data obtained by this method is convenient for knowing the characteristics of the electron gun, but it is necessary to imagine the state when mounted on an image display device.

The second and third methods have the advantage that the luminance distribution can be measured at once. But 3
In a color cathode ray tube in which electron beams are arranged inline,
When the electron beam passes through a color selection electrode (shadow mask, etc.), it does not become two-dimensionally continuous planar light emission, but only data as an aggregate of island light emission is obtained. The accuracy cannot be improved because the corresponding emission is obtained by a complementary calculation.

In particular, the third method directly obtains data of a state when mounted on an image display device, but it is difficult to accurately measure a high-speed pulse-like cathode current.

FIG. 5 is a schematic configuration diagram illustrating an apparatus for measuring the shape of an electron beam spot on the fluorescent screen of a color cathode ray tube. An electron beam 1B emitted from an electron gun 1A of a color cathode ray tube 1 is two-dimensionally deflected by a deflecting device 1C in a horizontal direction (X) and a vertical direction (Y), and passes through an opening of a color selection electrode 1D to form a fluorescent screen. The electron beam 1B collides with the constituent phosphor film 1E and emits light in a shape corresponding to the current density distribution of the electron beam 1B.
The emitted light is emitted to the outside of the cathode ray tube through the panel 1F, and the emitted light is converted into an electric signal by the photoelectric conversion element 20. The output of the photoelectric conversion element 20 is subjected to data processing in a signal processing device 21 and stored in a recording device 22. Recording device 22
Is output as visible information by the display device 1D or the printing device 1E as necessary.

FIG. 6 is an explanatory diagram of an example of a conventional sampling method for two-dimensionally measuring an emission distribution of an electron beam spot on a phosphor screen using the measuring apparatus shown in FIG.
FIG. 6 shows a cathode ray tube using a color selection electrode having a dot-hole-shaped electron beam passage hole as a color selection electrode, and the upper half of the fluorescent screen (horizontal when the center of the fluorescent screen is O). In the direction X, only X-OX, and in the vertical direction, only the range of Y-O) is schematically shown. A (A1 to A6) indicates a direct current to the coil of the deflection device in FIG. Shows the outer shape (electron beam spot) of the light emitting portion of the phosphor when the electron beam is shifted to the position by flowing the electron beam. The electron beam spot A is shown with an area larger than the area of the fluorescent screen 1E for easy understanding.

In FIG. 1, for example, when measuring the shape of the electron beam spot shape A3 located at the upper right corner of the fluorescent screen 1E and its luminance distribution, first, the horizontal direction X and the vertical direction X of the shape A of the electron beam spot shape A3 are measured. Direction Y is A
The luminance at each position of the matrix formed by dividing the matrix into m and n equally within the range where 3 can be accommodated is measured. By drawing an isoluminance line based on the measurement result, the shape and luminance distribution of A3 can be obtained. Of course, the data at the position deviating from each measurement point can be complementally calculated by a computer.
In addition, the narrower the interval between the measurement points when dividing into m and n, the higher the resolution can be obtained.

[0010] It should be noted that the portion B, which becomes a shadow of the color selection electrode, does not emit light. Since the lack of data at the point B where light does not emit lowers the measurement accuracy, a small step current is superimposed on the coil of the deflecting device using a measuring optical system with a pinhole to measure light only at the point P at the light emitting point. I have to.

[0011]

FIG. 7 shows a cathode ray tube using a color selection electrode having slits or interdigital electron beam passage holes as a color selection electrode on a fluorescent screen using the measuring apparatus shown in FIG. FIG. 9 is an explanatory diagram of an example of a conventional sampling method for two-dimensionally measuring an emission distribution of an electron beam spot. 6, the upper half of the fluorescent screen 1E (when the center of the fluorescent screen is O, the horizontal direction X is X
-OX, the vertical direction is the range YO only), and A (A1 to A6) also flows DC current to the coil of the deflection device of FIG. The external shape (electron beam spot) of the light emitting portion of the phosphor when the electron beam is shifted is shown. The electron beam spot A
Is shown with an area larger than the area of the fluorescent screen 1E for easy understanding, as in FIG.

Also in this example, for example, when measuring the shape of the electron beam spot shape A3 located at the upper right corner of the phosphor screen 1E and its luminance distribution, the horizontal direction X and the vertical direction Y are set within a range where the electron beam spot A3 can be accommodated. The luminance at each position of the matrix formed by dividing into m and n is measured. Drawing an isoluminance line based on the measurement results gives A
3 and a luminance distribution are obtained. Of course, the data at the position deviating from each measurement point can be complementally calculated by a computer. Further, the narrower the interval between the measurement points when dividing into m and n, the higher the resolution can be obtained.

The portion B which becomes a shadow of the color selection electrode does not emit light. Since the lack of data at the point B where light does not emit lowers the measurement accuracy, a small step current is superimposed on the coil of the deflecting device using a measuring optical system with a pinhole to measure light only at the point P at the light emitting point. I have to.

FIG. 8 shows an electron beam spot shape A (A1 to A6) of FIG. 6 or FIG. 7 prepared based on the result obtained by processing the data obtained by using the measuring apparatus shown in FIG. FIG. 5 is a luminance distribution diagram shown in FIG. The target electron beam is a center beam (for green).

As shown in the figure, it can be seen that a detailed luminance distribution is obtained at each electron beam spot. However, since the emission of the dot pattern when actually mounted on the image display device is scanned for a time corresponding to the pulse width of the cathode current of the cathode ray tube, it is horizontally longer (horizontal than the pattern shown in FIG. 8). Direction) shape. In addition, a portion having a small diameter in the horizontal direction, particularly a portion having a high luminance, is averaged by scanning, and therefore should not be present.

Therefore, the measurement result of the related art shown in FIG. 5 is different from the light emission observed in an actual image display device. However, the advantage of this method is that the pulse width of the electron beam for emitting light can be widened because it is not measured while scanning the electron beam, and the peak value of the pulse can be accurately determined using an oscillograph or the like. Since the measurement can be performed and information on a portion corresponding to the shadow of the color selection electrode can also be obtained, a highly accurate luminance distribution can be obtained.

On the other hand, for example, when the light emission distribution of a dot pattern of an image display device is enlarged and measured by an imaging device such as a TV camera, the pulse height of the pulse is reduced because the pulse width of the dot pattern is narrow as is well known. It is difficult to measure with high accuracy, and information on the part corresponding to the shadow of the color selection electrode cannot be obtained, resulting in poor measurement accuracy. In addition, the frequency characteristics of the video amplifier of the image display device affect the performance of the original cathode ray tube. There is a problem that it is difficult to evaluate the characteristics of the above.

As described above, in the prior art, the luminance distribution of the electron beam spot in the stopped state can be measured with high accuracy, but it corresponds to the luminance distribution of the phosphor in the scanning state in which the cathode ray tube is mounted on the image display device. It is not possible to measure the state of measurement, or a measurement corresponding to the luminance distribution of the phosphor mounted on the image display device is possible, but there has been only a method of inferior measurement accuracy.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a method and an apparatus for measuring the shape of an electron beam of a phosphor of a cathode ray tube in a state of being mounted on an image display device. It is in.

[0020]

In order to achieve the above object, the present invention provides a method for measuring the luminance distribution of a phosphor corresponding to a stationary electron beam distribution within a period corresponding to a pulse width of a cathode current. , The data are added while being slightly shifted in the scanning direction, and data corresponding to the light emission distribution of the phosphor screen is obtained in a state of being mounted on the image display device.

Further, the result of measuring the electron beam distribution in the stationary state is added while being shifted slightly in the scanning direction within a period corresponding to the pulse width of the cathode current, and the phosphor screen is mounted on the image display device. When obtaining data corresponding to the light emission distribution of the image display device, by taking into account the correction of the luminance saturation characteristics of the phosphor, the afterglow characteristics of the phosphor, the frequency characteristics of the video circuit of the image display device, etc. Thus, data corresponding to the emission distribution of the phosphor screen is obtained with higher accuracy.

That is, the present invention is characterized in that it is typically configured as described in the following (1) to (4).

(1) Data obtained by measuring the luminance distribution of a phosphor emitting light by an electron beam shifted to an arbitrary position on a phosphor screen is scanned within a time corresponding to a pulse width of a cathode current. It is characterized by obtaining data that approximates the state when a cathode ray tube is mounted on an image display device by adding and combining while shifting in the direction.

(2) In the method of (1), a correction is made in consideration of the luminance saturation characteristic of the phosphor and / or the frequency characteristic of the video circuit of the image display device and / or the afterglow characteristic of the phosphor. .

(3) At least a neck portion for accommodating an electron gun, a panel portion having a phosphor screen formed by applying a phosphor on the inner surface, and an electron beam emitted from the electron gun being horizontally and vertically on the phosphor screen. A cathode ray tube beam shape measuring device for measuring a shape formed by a brightness distribution of an electron beam spot formed on the phosphor screen of a cathode ray tube having a deflection device having a deflection coil for scanning in a two-dimensional direction. A photometric sensor that is installed on the outer surface of the panel unit of the cathode ray tube and detects light emission of a phosphor constituting the phosphor screen to generate an electric signal; and the phosphor that is installed on the light incident side of the photometric sensor. A light measuring unit having at least a pinhole for allowing only one light emission to enter the light measuring sensor, and shifting the electron beam to a predetermined position on the phosphor screen by a deflecting coil of the deflecting device. A signal generator that generates a step current for sequentially microdeflecting the electron beam in the scanning direction according to the pulse width of the cathode current based on the DC current and the shifted position, a DC current generated by the signal generator, An operation unit including at least a deflection circuit for applying a step current to a coil of the deflection device; a data processing unit for calculating a brightness value based on an output signal of the photometric sensor; and brightness data processed by the data processing unit And a main control unit for controlling the operation of each unit.

(4) The pinhole in (3) is formed on a mirror having a reflecting surface on the fluorescent screen side, and a TV camera that captures an image of the fluorescent screen through the reflecting mirror and an image captured by the TV camera. An image monitor for displaying the image, and adjusting the alignment between the phosphor and the pinhole while observing an image of the phosphor screen displayed on the image monitor.

It should be noted that the present invention is not limited to the above configuration, and various modifications can be made without departing from the scope of the technical idea described in the claims.

[0028]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram illustrating an example of an apparatus configuration for executing the method for measuring a beam shape of a cathode ray tube according to the present invention. 1 is a color cathode ray tube, 2 is a deflection device,
Reference numeral 3 denotes an operation unit, 4 denotes a control unit, 5 denotes a frame memory, 6 denotes a measurement unit, 7 denotes a data processing unit, 8 denotes a sensor power supply, 9 denotes a printer, and 10 denotes an image monitor.

The console 3 comprises an operation section 3A, a video circuit 3B, a deflection circuit 3C, a signal generator 3D, and a power supply 3E. The measuring section 6 includes a light receiving window 6A, a mirror 6B with a pinhole 6BA, a photometric sensor 6C, a lens 6D, and a TV camera 6E. The control unit 4 is configured by a computer such as a personal computer.

The operation unit 3A of the console 3 has a signal generator 3D
Are selected and applied to the cathode of the color cathode ray tube as a video signal for the color cathode ray tube. In addition, the signal generator 3D generates various deflection currents for measurement (a DC current for shifting to a predetermined position, a step-like current for minute deflection, and the like) and supplies the generated deflection current to the deflection device 2.

In other words, the operating section 3A applies the DC deflection current (to stop the electron beam at a predetermined position) and the minute step current (to sequentially move the electron beam in the scanning direction) applied to the deflection device 2 from the deflection circuit 3C. The setting of the measurement mode of the color cathode ray tube 1 is performed, such as the setting of (1). Deflection circuit 3C
Is a direct current for shifting an electron beam to an arbitrary position on the phosphor screen of the color cathode ray tube 1 to stop the electron beam, and a scanning direction (horizontal or vertical direction, here, horizontal direction) for a time corresponding to the pulse width of the cathode current. ) Is applied to the deflecting device 2 in such a manner as to sequentially shift the current.

The light emitted from the fluorescent screen enters the measuring section 6 from the light receiving window 6A of the measuring section 6, and enters the photometric sensor 6C through the pinhole 6BA of the mirror 6B having the pinhole 6BA.
The photometric sensor 6C converts the received light into an electric signal and supplies the electric signal to the data processing unit 7. The data processing unit 7 corresponds to the position of the pinhole of the phosphor emitting by the electron beam shifted to a predetermined position on the phosphor screen in accordance with the input signal (for shifting the shifted electron beam sequentially in the scanning direction). The luminance data representing the luminance distribution of the minute staircase deflection current is calculated and stored in the frame memory 5 via the control unit 4.

In this calculation, data obtained by measuring the luminance distribution of the phosphor emitting light by the shifted electron beam is added and synthesized while being shifted in the scanning direction by a time corresponding to the pulse width of the cathode current. Thus, data that approximates the state when the cathode ray tube is mounted on the image display device is obtained.

On the other hand, the light from the phosphor screen reflected by the mirror 6B having the pinhole 6BA is photographed by the TV camera 6E through the lens 6D. The photographed light emission state of the phosphor screen is displayed on the image monitor 10, and the position of the pinhole 6BA is adjusted while observing the image shown on the image monitor 10, and the pinhole 6B of the mirror 6B with the pinhole 6BA is adjusted.
Adjust A to a position suitable for luminance measurement (point P in FIGS. 6 and 7).

The luminance data stored in the frame memory 5 is printed out by the printer 9 under the control of the control device 4 to obtain the luminance pattern (the shape of the electron beam spot) shown in FIG.

FIGS. 2A and 2B are explanatory diagrams of a method for measuring the brightness of an electron beam spot on a phosphor screen by a micro-step deflection current according to the present invention. FIG. 2A shows electrons on the phosphor screen by application of a micro-step deflection current (I). beam is spot, since the pulse width of the actual cathode current (I) have a width from T ₀ of T ₁ of the (b), X from the electron beam spot X ₀ on the phosphor screen of the image display device during this time Move to ₁ .

Therefore, the diameter "X diameter" of the portion that actually emits light in the scanning direction (X direction) is larger than the value measured by the method described with reference to FIGS. In order to obtain a luminance distribution equivalent to the pulse width with high accuracy, the luminance distribution obtained in FIGS. 6 and 7 is overlapped between X ₀ and X ₁ while being shifted in the scanning direction by, for example, dX. An accurate light emission luminance distribution corresponding to the scanning state is obtained. Figure (c)
Shows a state in which the shape of the signal pulse is deformed due to the influence of the frequency characteristics of the video amplifier of the image display device. When a cathode ray tube is mounted on such an image display device, a luminance distribution corresponding to visual observation at the time of mounting can be obtained by adding a correction according to the deformation of the pulse to the luminance near the rising of the pulse.

FIG. 4D shows the afterglow characteristic (P is the afterglow luminance) of the phosphor. By correcting the afterglow characteristic, a more accurate luminance distribution can be obtained. That is, (e) is a schematic diagram of the electron beam spot as a result of taking into account the effects of (c) and (d), and the portion of A shows a range in which the cathode current generated due to a long pulse rise time is small (that is, The range B is a range where the cathode current is small because the pulse has a tail. Also,
The portion C indicates that as a result of the narrowing of the overlapping interval, the state is close to a smooth straight line.

FIG. 3 is a schematic diagram for explaining a method of calculating a luminance distribution using minute movement of an electron beam spot in the horizontal direction according to the present invention. For example, a case where the electron beam is shifted to the position A3 and the luminance distribution (beam spot shape) of the electron beam spot at this position is measured will be described as an example.

The brightness distribution of the electron beam spot formed on the fluorescent screen in this portion is referred to as "Figure 1" (original figure). The fluorescent screen constitute a "figure 1" in the horizontal direction X ₁ ~
X _n, divides vertically Y ₁ to Y _n. Assuming that the divided part is a cell, each cell is represented by (X, Y), the measured luminance is represented by (x, y), and the maximum luminance as a result of calculation from Y _{1 to} Y _n is represented by Z _p . The luminance of each cell at this time is calculated as follows.

[0042] The bottom row of the "figure 1", the cell _{(X 1, Y 1) =} (x 1, y 1) / Z p cell _{(X 2, Y 1) =} (x 1, y 1 + X ₂ , y ₁ ) / Z _p cell (X _n−1 , Y ₁ ) = (x ₁ , y ₁ + x ₂ , y ₁₎ ... X _n−1 , y _{1 + x n, y 1)} / Z p cells _{(X n, Y 1) =} (x 1, y 1 + x 2, y 1 + ····· ··· + x n, y 1 + x n, y 1) / Z _p cell (X _{n + 1} , Y ₁ ) = (x ₂ , y ₁ + x ₃ , y ₁ +... _Xn , y ₁ ) / Z _p cell (X _{2n-1, Y 1) =} (x n-1, y 1 + x n, y 1) / Z p cells _{(X 2n, Y 1) =} (x n, becomes y ₁₎ / Z _p.

Hereinafter, the second column from the bottom, the third column,.
····· Calculate the top row in the same way.

Next, the same calculation is performed for one cell in the horizontal direction, that is, the spot shape (“figure 2”) slightly moved from x ₁ to x ₂ , and this is calculated as x _n (“figure n”). )).

By adding all of the above, the luminance distribution shown as the "operation result", that is, the electron beam spot shape is obtained.

FIG. 4 is a luminance distribution diagram of an electron beam spot in which the calculation results of FIG. 3 are superimposed in the scanning direction of the phosphor screen. This luminance distribution corresponds to a case where a wide color cathode ray tube having a diagonal size of 78 cm is used to display a dot pattern having a cathode current pulse width of 250 ns when scanning horizontally at 15.75 kHz.

As can be seen from FIG. 4, each of the positions A1 to A6
In the brightness distribution shape of the electron beam spot in FIG. 8, the diameter in the horizontal direction (scanning line direction) is longer than that in FIG. 8, and the portion having a complicated shape in FIG. The spacing between the lines is significantly wider.

As described above, based on the result of measuring the spot shape of the electron beam resting on the phosphor screen, it is possible to approximate the dynamic electron beam spot shape that can be seen when mounted on an image display device. .

The mirror with a pinhole is installed for monitoring using a TV camera. When such a monitor is not used, a simple pinhole may be used.

The mechanism for adjusting the pinhole position is not limited to the one constituted by the TV camera 6E and the image monitor 10 in FIG. 1, but may be provided by providing an optical sighting mechanism in the photometry unit.

In the above embodiment, the minute deflection of the electron beam is in the horizontal direction. However, the present invention is not limited to this, and the same luminance distribution is measured in the vertical direction to change the shape of the electron beam spot. It is possible to get.

[0052]

As described above, according to the present invention,
The result of the measurement of the electron beam distribution in the stationary state is added for a period corresponding to the pulse width of the cathode current while being slightly shifted in the scanning direction, and the data corresponding to the emission distribution of the phosphor screen when mounted on the image display device. And the correction of the luminance saturation characteristics of the phosphor, the afterglow characteristics of the phosphor, the frequency characteristics of the video circuit of the image display device, etc. Corresponding data can be obtained with higher accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of an apparatus configuration for executing a method for measuring a beam shape of a cathode ray tube according to the present invention.

FIG. 2 is an explanatory diagram of a method for measuring the brightness of an electron beam spot on a phosphor screen using a small step deflection current according to the present invention.

FIG. 3 is a schematic diagram illustrating a method of calculating a luminance distribution using a minute movement of an electron beam spot in a horizontal direction according to the present invention.

4 is a brightness distribution diagram of an electron beam spot in which the calculation results of FIG. 3 are superimposed in a scanning direction of a phosphor screen.

FIG. 5 is a schematic configuration diagram illustrating an apparatus for measuring an electron beam spot shape on a fluorescent screen of a color cathode ray tube.

6 is an explanatory diagram of an example of a conventional sampling method for two-dimensionally measuring an emission distribution of an electron beam spot on a phosphor screen using the measuring device shown in FIG.

7 shows a cathode ray tube using a color selection electrode having a slit or an interdigital electron beam passage hole as a color selection electrode. FIG. 5 shows the emission distribution of an electron beam spot on a phosphor screen using the measurement apparatus shown in FIG. It is explanatory drawing of the conventional sampling method example for performing dimension measurement.

8 is a graph showing the electron beam spot shapes A (A1 to A6) shown in FIG. 6 or FIG. 7 created based on the data obtained by processing the data obtained by using the measurement apparatus shown in FIG. It is a brightness distribution figure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Color cathode ray tube 2 Deflection device 3 Operation part 3A Scanning part 3B Video circuit 3C Deflection circuit 3D signal generator 3E Power supply 4 Control part 5 Frame memory 6 Measurement part 6A Light receiving window 6B Mirror with pinhole 6C Photometric sensor 6D lens 6E TV camera 7 Data processing unit 8 Sensor power supply 9 Printer 10 Monitor.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Akio Araki 3681 Hayano, Mobara-shi, Chiba F-term in Hitachi Device Engineering Co., Ltd. QQ27 SS02 SS06 SS13

Claims (4)

[Claims] 1. A method in which data obtained by measuring a luminance distribution of a phosphor emitting by an electron beam shifted to an arbitrary position on a phosphor screen in a scanning direction within a time corresponding to a pulse width of a cathode current. A method for measuring the beam shape of a cathode ray tube, wherein data approximating a state when the cathode ray tube is mounted on an image display device is obtained by adding and synthesizing while shifting the image. 2. The method according to claim 1, wherein a correction is made in consideration of luminance saturation characteristics of the phosphor and / or frequency characteristics of an image circuit of the image display device and / or afterglow characteristics of the phosphor. Of measuring the beam shape of a cathode ray tube. 3. A panel portion having at least a neck portion for accommodating an electron gun and a phosphor screen formed by applying a phosphor on an inner surface thereof, and an electron beam emitted from the electron gun being horizontally and vertically formed on the phosphor screen. A cathode ray tube beam shape measuring device for measuring a shape formed by a brightness distribution of an electron beam spot formed on the phosphor screen of a cathode ray tube provided with a deflection device having a deflection coil for scanning in a two-dimensional direction, A photometric sensor that is installed on the outer surface of the panel portion of the tube and detects light emission of a phosphor constituting the phosphor screen and generates an electric signal; and one place of the phosphor that is installed on the light incident side of the photometric sensor A light-metering unit having at least a pinhole for causing only the light emitted from the light-emitting device to enter the light-metering sensor; and a deflection coil for shifting the electron beam to a predetermined position on the phosphor screen. A signal generator for generating a step current for sequentially minutely deflecting the electron beam in the scanning direction according to the pulse width of the cathode current based on the current and the shifted position; a DC current generated by the signal generator; An operation unit including at least a deflection circuit that applies a current to the coil of the deflection device; a data processing unit that calculates a luminance value based on an output signal of the photometric sensor; and a luminance data processed by the data processing unit. A beam shape measuring device for a cathode ray tube, comprising: a frame memory for storing; and a main control unit for controlling the operation of each unit. 4. A TV camera, wherein the pinhole is formed in a mirror having a reflection surface on the fluorescent surface side, and a TV camera for capturing an image of the fluorescent surface through the reflection mirror, and an image monitor for displaying an image captured by the TV camera. 4. The apparatus according to claim 3, further comprising: adjusting an alignment between the phosphor and the pinhole while observing an image of the phosphor screen displayed on an image monitor. 5.