JPH0847005A - Electron beam landing state detection method - Google Patents

Abstract

(57) [Abstract] [Purpose] Easy to detect the landing state of the electron beam on the segmented phosphor in the display screen part of the cathode ray tube, because the detection accuracy is improved and the preparation of the detection coil is unnecessary. So that you can do it with simple work. Constitution: Cathode ray tube 3 equipped with velocity modulation deflection coil 31
For 0, the electron beam has a deflection coil 31 for velocity modulation.
Under the condition that the display screen unit 14 is repeatedly scanned by the electron beam deflection coil 15 without being subjected to the auxiliary horizontal deflection that causes the modulation of the horizontal scanning velocity by the By supplying a wobbling signal, the arrival position of the electron beam on the display screen unit 14 is changed in the horizontal direction according to the wobbling signal, and the display screen unit accompanying the change of the arrival position of the electron beam according to the wobbling signal. The display screen unit 1 based on the change state of the brightness in 14
The landing state of the electron beam on the segmented fluorescent body 13 arranged in No. 4 is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display image on a display screen section by emitting colored light when each of a large number of segmented fluorescent bodies arranged on the display screen section is excited by an electron beam from an electron beam generating means. The present invention relates to an electron beam landing state detection method for detecting the landing state of an electron beam with respect to a section fluorescent body of a cathode ray tube.

[0002]

2. Description of the Related Art A color image display apparatus, a typical one of which is a color television receiver, includes an electron beam generator, and a plurality of sections which emit colored light when excited by an electron beam emitted from the electron beam generator. A display screen unit having a fluorescent material and an electron beam deflecting unit for deflecting the electron beam emitted from the electron beam generating unit to reach the display screen unit for repetitive scanning in the horizontal and vertical directions. The cathode ray tube is used, and the color image signal is supplied to the electron beam generating portion of the cathode ray tube, and the electron beam emitted from the electron beam generating portion is density-modulated according to the color image signal. A reproduced color image based on a color video signal can be obtained on the display screen portion of the cathode ray tube. The large number of segmented fluorescent bodies arranged on the display screen portion of the cathode ray tube are in the form of stripes, dots, etc., and are arranged in a predetermined arrangement or arrangement.

In such a color image display device, in the cathode ray tube, the display screen portion of the electron beam emitted from the electron beam generation portion and made to reach the display screen portion for repeated scanning in the horizontal and vertical directions. In order to obtain a good reproduction color image, it is assumed that the arrival position at is such that the landing of the electron beam with respect to each of the large number of segmented phosphors arranged on the display screen can be properly maintained. Is one of the important requirements for The state in which the landing state of the electron beam on each of the plurality of section fluorescent bodies is properly maintained means that the electron beam that repeatedly scans the display screen section in the horizontal and vertical directions has a large number of section phosphors on the display screen section. It is in a state where the central portions of the respective light bodies are arranged so that the central portions thereof coincide with the central portions of the respective fluorescent bodies.

Therefore, in the manufacturing process of the color image display device, at the stage where the electron beam deflector and the cathode ray tube can be brought into the normal operating state,
Detection of the electron beam landing state of the cathode ray tube and electron beam landing adjustment based on the detection result are performed. A wobbling method has been proposed as a method used for detecting the electron beam landing state in such a case.

When the electron beam landing state is detected by the conventionally proposed wobbling method, for example, as shown in FIG. 5, a neck portion 12 having an electron beam generating portion 11 built therein and, for example, a neck portion 12 , A large number of segmented phosphors 13, each striped
Has a display screen portion 14 disposed inside thereof, and a cathode ray tube 16 further provided with an electron beam deflection coil 15 outside thereof, a landing detection coil for detecting an electron beam landing state. 17
Is attached. At that time, the landing detection coil 17
As shown in FIG. 6, it comprises a pair of interconnected annular coil members 17U and 17D. Outside the neck portion 12 of the cathode ray tube 16, the pair of annular coil members 17U and 17D is attached to the neck portion. 12 are arranged so as to sandwich 12 from above and below. The landing detection coil 17 is not included in the color image display device, but is removed from the neck portion 12 of the cathode ray tube 16 after the detection and adjustment of the electron beam landing state of the cathode ray tube 16 are completed. It is removed and constitutes a part of the landing detection device used in the manufacturing process of the color image display device.

Electron beam generator 1 in cathode ray tube 16
1 is capable of forming, for example, three electron beams for red, green and blue, and is supplied with a red video signal, a green video signal and a blue video signal. The red electron beam, the green electron beam, and the blue electron beam, respectively.
It is generated as density-modulated according to the red video signal, the green video signal and the blue video signal. The red electron beam, the green electron beam, and the blue electron beam are, for example, arranged in a horizontal direction, the green electron beam is arranged in the center, and the red electron beam and the blue electron beam are arranged on both sides thereof. To be done.

Further, the display screen portion 1 of the cathode ray tube 16
The large number of segmented fluorescent bodies 13 arranged in 4 should be, for example, a red stripe fluorescent body that should be excited by a red electron beam to emit red light, and a green striped fluorescent body that should be excited by a green electron beam. It is assumed that a green striped phosphor and a set of blue striped phosphors that emit blue light when excited by a blue electron beam are sequentially arranged adjacent to each other. In addition, the electron beam deflection coil 15
Is a vertical deflection signal SDV and a horizontal deflection signal SDV supplied from the vertical deflection signal forming unit 20 for each of the red electron beam, the green electron beam and the blue electron beam emitted from the electron beam generating unit 11 in the cathode ray tube 16. The light is deflected according to the horizontal deflection signal SDH supplied from the deflection signal forming unit 21 and reaches the inside of the display screen unit 14 on which the section fluorescent bodies 13 are arranged in order to perform repeated scanning in the horizontal and vertical directions. Let

Under these circumstances, the electron beam deflection coil 15
And the vertical deflection signal SDV from the vertical deflection signal forming unit 20.
And the horizontal deflection signal SDH from the horizontal deflection signal forming unit 21, and the green primary color signal GL from the green primary color signal supply unit 18 is supplied to the electron beam generation unit 11 as a green video signal, thereby. , Only the electron beam for green whose density is modulated by the green primary color signal GL is emitted from the electron beam generator 11, and the electron beam for green is
The electron beam deflection coil 15 receives a vertical deflection action in accordance with the vertical deflection signal SDV and a horizontal deflection action in accordance with the horizontal deflection signal SDH, so that it is placed inside the display screen portion 14 in which the section fluorescent body 13 is arranged. The condition is reached to perform a repetitive horizontal and vertical scan with respect to. Then, the wobbling signal SW from the wobbling signal generator 22 is supplied to the landing detection coil 17 mounted on the outside of the neck portion 12 of the cathode ray tube 16.

As shown in FIG. 7, the wobbling signal SW is generated every vertical cycle (1 vertical cycle = 1V) of the vertical deflection signal SDV from the vertical deflection signal forming section 20 and the vertical synchronization signal SV in a synchronous state. A pulse signal having a period of 2 V is obtained by alternately taking a high level portion having a high level and a low level portion having a low level as compared with a predetermined reference level VR. Due to the action of the landing detection coil 17 to which the wobbling signal SW is supplied, the electron beam deflection coil 15 receives a vertical deflection action and a horizontal deflection action to generate an electron beam that reaches the inside of the display screen unit 14. It is assumed that the green electron beam from the unit 11 is also deflected according to the wobbling signal SW,
The arrival position of the green electron beam from the electron beam generator 11 inside the display screen 14 is 1 V depending on the high level portion and the low level portion of the wobbling signal SW.
It can be changed every time.

FIG. 8 and FIG. 9 show the display screen unit 1 for the green electron beam from the electron beam generator 11 as described above.
An example of the change of the arrival position inside 4 is shown. In FIG. 8 and FIG. 9, a large number of segmented fluorescent bodies 13 arranged inside the display screen section 14 are provided with red stripe-shaped fluorescent bodies R, in each of which a black stripe light absorber K is arranged.
It is supposed to include a striped phosphor G for green and a striped phosphor B for blue, and further inside the large number of segmented phosphors 13, a striped phosphor R for red and a green. A color selection electrode 19 provided with slits 19A forming a large number of openings corresponding to the striped phosphor G for light G and the striped phosphor B for blue is arranged.
Then, the green electron beam EG from the electron beam generator 11 passes through the slits 19A corresponding to the green stripe phosphor G provided in the color selection electrode 19 and the green stripe phosphor G and both sides thereof. To reach the black stripe light absorber K.

In FIG. 8 and FIG. 9, the green electron beam EG indicated by the solid line represents a state where it is not deflected according to the wobbling signal SW, and the green electron beam EG and the two-dot electron beam EG indicated by the alternate long and short dash line. The green electron beam EG indicated by the dotted line represents the states corresponding to the high-level portion and the low-level portion of the wobbling signal SW under the deflection in accordance with the wobbling signal SW. In the example shown in FIGS. 8 and 9, the inside of the display screen portion 14 of the green electron beam EG through the slit 19A corresponding to the green stripe-shaped phosphor G provided in the color selection electrode 19. The arrival position at is in accordance with the high level part of the wobbling signal SW,
The arrival position when the deflection according to the wobbling signal SW is not received is changed to the lower side in FIGS. 8 and 9, and according to the low level portion of the wobbling signal SW, the wobbling signal SW is determined. It is changed to the upper side in FIGS. 8 and 9 from the arrival position when it is not deflected.

In the state of FIG. 8, the landing of the green electron beam EG with respect to the green stripe-shaped phosphor G in the large number of segmented phosphors 13 arranged inside the display screen portion 14 is in a proper state, When the green electron beam EG is not deflected according to the wobbling signal SW, the green electron beam EG passing through the slit 19A corresponding to the green stripe-shaped phosphor G provided on the color selection electrode 19 is The center is made to coincide with the center of the green striped phosphor G, and the green striped phosphor G and the black stripe light absorbers K on both sides thereof are reached. Under such a state, the green electron beam EG is deflected in accordance with the wobbling signal SW, and the arrival position inside the display screen unit 14 is changed in accordance with the high level portion and the low level portion of the wobbling signal SW. Even if it is changed for each 1V, the change of the reaching position is kept within the range of the green stripe fluorescent substance G and the black stripe light absorbers K on both sides thereof. Therefore, the light emission state of the green stripe G for excitation by the electron beam EG for green is always assumed to be that the green stripe G for green emits light over its entire width, and the green The deflection of the application electron beam EG according to the wobbling signal SW is not affected, and thereby the brightness of the green stripe phosphor G on the display screen unit 14 is maintained constant.

On the other hand, in the state of FIG. 9, the landing of the green electron beam EG with respect to the green stripe-shaped phosphors G in the large number of segmented phosphors 13 arranged inside the display screen portion 14 is inappropriate. In this state, the green electron beam EG is not deflected according to the wobbling signal SW, and the green through the slit 19A corresponding to the green stripe-shaped phosphor G provided in the color selection electrode 19 When the center of the electron beam EG for the green is displaced from the center of the green striped phosphor G to the blue striped phosphor B side (upper side in FIG. 9), the green striped phosphor G is formed. And the black stripe light absorbers K on both sides thereof. Under such a state, the green electron beam EG emits the wobbling signal SW.
When the arrival position inside the display screen unit 14 is changed by 1V according to the high level part and the low level part of the wobbling signal SW, the change of the arrival position is changed to the green stripe. It exceeds the range of the fluorescent substance G and the black stripe light absorbers K on both sides thereof. For example, the arrival position corresponding to the high level part of the wobbling signal SW is kept within the range of the green stripe fluorescent substance G and the black stripe light absorbers K on both sides thereof, but the low level part of the wobbling signal SW is kept. The arrival position corresponding to the black stripe light absorber K between the green striped phosphor G and the blue striped phosphor B.
Beyond, the position is changed to a position where it enters the blue striped phosphor B, and as a result, the portion G ′ of the green striped phosphor G on the red striped phosphor R side is The area is not reached by the green electron beam EG.

That is, in such a case, when the wobbling signal SW is at a high level portion, the green stripe-shaped phosphor G is covered by the green electron beam EG over its entire width. Although it is supposed to be excited to emit light, when the wobbling signal SW has a low level portion, the green striped phosphor G is a portion G on the red striped phosphor R side. 'For electron beam EG for green
Therefore, it is assumed that the light is emitted because it is not excited by the light. As a result, the brightness of the green stripe-shaped phosphor G in the display screen section 14 becomes
There is a difference between when the wobbling signal SW takes the high level part and when the wobbling signal SW takes the low level part.

Display screen section 1 of cathode ray tube 16
A green light detector 25 is arranged on the outer surface side of 4. The green light detector 25 is, for example, formed in a tubular shape as a whole, receives light incident from one end thereof through a filter that passes only green light, detects the intensity of green light passing through the filter, and is detected. It is assumed that a detection output signal representing the intensity is generated. Then, one end of the green light detector 25 is brought into contact with the display screen portion 14 from the outside. Thereby, in the green light detector 25,
The green light emitted from the green striped phosphor G arranged inside the display screen portion 14 which is incident from one end thereof is received through the filter, the intensity thereof is detected, and the detection of the intensity of the detected green light is performed. The output signal SG is sent out.

The detection output signal SG obtained from the green light detector 25 is amplified by the amplification section 26 and supplied to the sampling section 27. The sampling unit 27 includes a wobbling signal SW from the wobbling signal generation unit 22.
Is also supplied. Then, in the sampling unit 27, the wobbling signal SW of the detection output signal SG is used.
Of the wobbling signal SW of the detection output signal SG and the state where the sampling output signal SGL is obtained by sampling the portion corresponding to the high level portion of
Sampling is performed on the portion corresponding to the low-level portion of, and the sampling output signal SGR is obtained.

Sampling output signal SGL and sampling output signal SGR obtained from sampling section 27
Are supplied to the comparison unit 28. In the comparison unit 28,
Sampling output signal SGL and sampling output signal S
After being synchronized with GR, mutual comparison is performed by taking the difference between them, and as a result, a comparison output signal SO representing the difference between the sampling output signal SGL and the sampling output signal SGR is obtained. Then, the comparison output signal SO is output to the output terminal 29.

The comparison output signal SO obtained at the output terminal 29 in this manner corresponds to the brightness of the green stripe-shaped phosphor G in the display screen portion 14, and is distributed, for example, inside the display screen portion 14. The landing of the green electron beam EG with respect to the green striped phosphors G in the plurality of divided phosphors 13 performed is in an appropriate state, whereby the green striped phosphors G in the display screen portion 14 are When the brightness is kept constant without being influenced by the deflection of the green electron beam EG in accordance with the wobbling signal SW, it takes a zero level, and a large number of pixels arranged inside the display screen unit 14 are provided. When the landing of the green-colored electron beam EG on the green-colored stripe-shaped fluorescent body G in the segmented fluorescent body 13 is not appropriate, If the brightness of the green stripe-shaped phosphor G in the lean portion 14 is different when the wobbling signal SW takes a high level portion and when the wobbling signal SW takes a low level portion, the difference is obtained. The predetermined level is set according to the degree of. Therefore, on the basis of the state of the comparison output signal SO obtained at the output terminal 29, the green striped phosphors G in the large number of segmented phosphors 13 arranged inside the display screen portion 14 are provided.
The landing state of the green electron beam EG with respect to is detected.

In the cathode ray tube 16, the landing of the blue electron beam on the blue striped phosphor B in the large number of segmented phosphors 13 arranged inside the display screen part 14 and the display screen part. The landing of the red electron beam with respect to the red stripe-shaped phosphor R in the large number of sectional fluorescent bodies 13 arranged inside 14 is also achieved in the large number of sectional fluorescent bodies 13 arranged inside the display screen portion 14. It should be in the same state as the landing of the green electron beam EG on the green stripe G. Therefore, based on the state of the comparison output signal SO obtained at the output terminal 29, the display screen unit 14
The landing state of each electron beam with respect to each of the large number of segmented fluorescent bodies 13 arranged inside is detected.

[0020]

As described above, the landing detecting coil is attached to the neck portion of the cathode ray tube, and the wobbling signal is supplied to the landing detecting coil, so that the cathode ray tube is operated. In order to detect the landing state of the electron beam from the electron beam generator with respect to the large number of segmented fluorescent bodies arranged inside the display screen in, the attachment / detachment of the landing detection coil to the neck of the cathode ray tube must be performed. There are some inconveniences that result. These inconveniences can be summarized as follows.

First, the mounting of the landing detection coil on the neck portion of the cathode ray tube is performed manually by each operator. Therefore, the mounting state of the landing detection coil for each cathode ray tube is considerably or subtly. However, such a difference affects the detection of the landing state of the electron beam, which may lead to a decrease in detection accuracy. In addition, not only the electron beam deflection coil but also various adjusting coil devices, adjusting magnet devices and the like are often arranged at the neck portion of the cathode ray tube. In addition to these, it is necessary to attach and detach the landing detection coil. Doing it properly is quite difficult and requires time-consuming work. Furthermore, when a plurality of types of cathode ray tubes having different neck portions are targeted, a plurality of types of landing detection coils having dimensions according to the dimensions of the neck portion of each cathode ray tube must be prepared. It will not happen.

In view of the above point, the present invention is provided with a display screen section in which a large number of sectional fluorescent bodies which are excited by the electron beam from the electron beam generating means and emit light are arranged.
A cathode ray tube having an electron beam deflecting means for deflecting the electron beam from the electron beam generating means to reach the display screen portion for repetitive scanning in the horizontal and vertical directions. It is easy to detect the landing state of the electron beam from the electron beam generating means on the light body under the condition that the detection accuracy is improved and it is not necessary to prepare a plurality of types of detection coils. It is an object of the present invention to provide an electron beam landing state detection method that can be performed by a simple operation.

[0023]

In order to achieve the above-mentioned object, an electron beam landing state detecting method according to the present invention is provided with an electron beam generating means and a large number of light sources which are excited by an electron beam from the electron beam generating means. A display screen section on which the section fluorescent body is arranged, electron beam deflecting means for deflecting the electron beam from the electron beam generating means to reach the display screen section for repetitive scanning in the horizontal and vertical directions, and display. A cathode ray tube provided with a deflection means for velocity modulation arranged to add an auxiliary horizontal deflection that causes modulation of a horizontal scanning velocity to an electron beam that is made to reach a screen portion for repeated horizontal and vertical scanning. Auxiliary water in which the electron beam from the electron beam generation means causes the horizontal scanning speed to be modulated by the speed modulation deflecting means. Under the condition that the display screen section is repeatedly scanned in the horizontal direction and the vertical direction by the electron beam deflecting means without being deflected, a wobbling signal is supplied to the velocity modulating deflecting means for display. The arrival position of the electron beam in the screen part is changed in the horizontal direction according to the wobbling signal, and based on the change state of the brightness in the display screen part due to the change in the arrival position of the electron beam in the display screen part according to the wobbling signal. Then, the landing state of the electron beam with respect to the section fluorescent body arranged on the display screen is detected.

[0024]

In the electron beam landing state detecting method according to the present invention as described above, the electron beam landing state required for detecting the landing state of the electron beam with respect to the section fluorescent body arranged on the display screen portion is The cathode ray tube is provided with the electron beam deflecting means, together with the electron beam deflecting means, to change the arrival position of the electron beam, which is made to reach the display screen portion under the deflection action of the beam deflection coil, in the display screen portion according to the wobbling signal. It is caused by supplying the wobbling signal to the velocity modulation deflecting means. Therefore, when detecting the landing state of the electron beam with respect to the segmented fluorescent body arranged on the display screen portion, it is not necessary to attach or detach the landing detection coil to or from the neck portion of the cathode ray tube.

Therefore, when the electron beam landing state detecting method according to the present invention is carried out to detect the landing state of the electron beam with respect to the segmented fluorescent body arranged on the display screen portion of the cathode ray tube, the cathode ray line is detected. Inconveniences caused by attaching and detaching the landing detection coil to the neck portion of the pipe are resolved, the detection accuracy is improved, and it is not necessary to prepare multiple types of detection coils. With that, it will be done with easy and simple work.

[0026]

FIG. 2 shows an example of a part of a color image display device equipped with a cathode ray tube and a detection device to which the electron beam landing state detection method according to the present invention is applied.

The cathode ray tube 30 to which the electron beam landing state detecting method according to the present invention shown in FIG. 2 is applied,
Similar to the cathode ray tube 16 shown in FIG. 5, a display in which a neck portion 12 having an electron beam generating portion 11 built therein and, for example, a large number of segmented fluorescent bodies 13 each having a stripe shape are arranged inside It has a screen portion 14 and further has an electron beam deflection coil 15 on the outside thereof. The cathode ray tube 30 is provided with a velocity modulation deflection coil 31 in addition to the electron beam deflection coil 15 at the neck portion 12.

The velocity modulation deflection coil 31, as shown in FIG. 1, is formed of a pair of annular coil members 31U and 31D, each of which is formed into a shape that follows the outer surface of the neck portion 12 and is interconnected. Cathode ray tube 30
A pair of annular coil members 31U and 31D are attached to the outside of the neck portion 12 in the above so as to sandwich the neck portion 12 from above and below. Like the electron beam deflection coil 15, the velocity modulation deflection coil 31 is included in the color image display device.

Electron beam generator 1 in cathode ray tube 30
1 is capable of forming, for example, three electron beams for red, green and blue, and is supplied with a red video signal, a green video signal and a blue video signal. The red electron beam, the green electron beam, and the blue electron beam, respectively.
It is generated as density-modulated according to the red video signal, the green video signal and the blue video signal. The red electron beam, the green electron beam, and the blue electron beam are, for example, arranged in a horizontal direction, the green electron beam is arranged in the center, and the red electron beam and the blue electron beam are arranged on both sides thereof. To be done.

Further, the display screen portion 1 of the cathode ray tube 30.
The large number of segmented fluorescent bodies 13 arranged in 4 should be, for example, a red stripe fluorescent body that should be excited by a red electron beam to emit red light, and a green striped fluorescent body that should be excited by a green electron beam. It is assumed that a green striped phosphor and a set of blue striped phosphors that emit blue light when excited by a blue electron beam are sequentially arranged adjacent to each other. In addition, the electron beam deflection coil 15
Is a vertical deflection signal SDV supplied from the vertical deflection signal forming unit 20 and a horizontal deflection signal SDV supplied from the vertical deflection signal forming unit 20 to the red electron beam, the green electron beam and the blue electron beam emitted from the electron beam generating unit 11 in the cathode ray tube 30. The light is deflected according to the horizontal deflection signal SDH supplied from the deflection signal forming unit 21 and reaches the inside of the display screen unit 14 on which the section fluorescent bodies 13 are arranged in order to perform repeated scanning in the horizontal and vertical directions. Let

The deflection coil 31 for velocity modulation is used in the cathode ray tube 3.
The red image signal, the green image signal, and the blue image signal are supplied to the electron beam generation unit 11 at 0, and the electron beam deflection coil 15 causes the vertical deflection signal SDV and the horizontal deflection signal formation unit 21 from the vertical deflection signal formation unit 20. When the color image display device is set to perform the normal image display operation in a state of performing the electron beam deflection operation according to the horizontal deflection signal SDH from, the speed modulation signal forming unit 33 outputs the signal through the terminal 32. The velocity modulation signal SVM is supplied. The velocity modulation signal SVM is supposed to change according to the levels of the luminance component signals in the red image signal, the green image signal and the blue image signal supplied to the electron beam generator 11.

For example, as shown in FIG. 3A, the luminance component signal SY in the red image signal, the green image signal and the blue image signal supplied to the electron beam generator 11 shows the increase in the luminance Sa. And a level change forming a falling portion Sb representing a decrease in brightness,
As shown in FIG. 3B, the velocity modulation signal SVM has a predetermined positive level portion SA according to the rising portion Sa of the luminance component signal SY and has a predetermined positive level portion SA according to the falling portion Sb of the luminance component signal SY. , And has a negative level portion SB, and takes a zero level at other times. Then, the velocity modulation signal SVM is supplied to the velocity modulation deflection coil 31, whereby the velocity modulation deflection coil 31 is moved to the cathode ray tube 30.
In the inside, the red color from the electron beam generating unit 11 is made to reach the inside of the display screen unit 14 in which the section fluorescent body 13 is arranged by the electron beam deflection coil 15 in order to perform repeated scanning in the horizontal direction and the vertical direction. The auxiliary electron beam for green, the electron beam for green, and the electron beam for blue are each subjected to auxiliary horizontal deflection that causes modulation of the horizontal scanning speed.

That is, the deflection coil 31 for velocity modulation is provided with
By supplying the velocity modulation signal SVM as shown in B of FIG. 1, the electron beam for red and the electron beam for green which are made to reach the inside of the display screen portion 14 to perform repetitive scanning in the horizontal and vertical directions. The horizontal scanning speed of each of the blue electron beam and the blue electron beam is increased according to the positive level portion SA of the speed modulation signal SVM, and the horizontal scanning speed is decreased according to the negative level portion SA of the speed modulation signal SVM. It is supposed to be punished. As a result, the change in the brightness according to the brightness component signal SY in the display screen unit 14 is, for example, as shown in FIG.
(Horizontal axis: electron beam scanning position PS on display screen, vertical axis: brightness BGT on display screen)
In contrast to what is indicated by the solid line in
Under the condition that the velocity modulation signal SVM is supplied to the velocity modulation deflection coil 31 and the auxiliary horizontal deflection operation is performed, it is as shown by the alternate long and short dash line in FIG. That is, when the change in brightness according to the brightness component signal SY in the display screen unit 14 causes the auxiliary horizontal deflection operation by the speed modulation deflection coil 31, the auxiliary horizontal deflection operation by the speed modulation deflection coil 31 is performed. As compared with when there is no light, the dark state changes more rapidly to the bright state, and vice versa. As a result, the sharpness of the display image on the display screen unit 14 is increased. Will be improved.

In carrying out the electron beam landing state detecting method according to the present invention under such a condition, the vertical deflection signal SDV and the horizontal deflection signal from the vertical deflection signal forming section 20 are applied to the electron beam deflection coil 15. Forming part 2
The horizontal deflection signal SDH from 1 is supplied,
The green primary color signal GL from the green primary color signal supply unit 18 is supplied to the electron beam generation unit 11 as a green video signal,
As a result, the green primary color signal G is emitted from the electron beam generator 11.
Only the green electron beam whose density is modulated by L is emitted, and the green electron beam is emitted by the electron beam deflection coil 1
5, the vertical deflection action according to the vertical deflection signal SDV and the horizontal deflection action according to the horizontal deflection signal SDH are received, and inside the display screen portion 14 in which the section fluorescent body 13 is arranged, the horizontal direction and A state is reached in which a repetitive scan in the vertical direction is performed. Further, in such a case, the connection between the terminal 32 and the velocity modulation signal forming unit 33 is cut off, so that the velocity modulation signal SVM is not supplied to the velocity modulation deflection coil 31, and the electron beam generation unit 11 does not.
The electron beam for green from is the deflection coil 31 for velocity modulation.
Is not subjected to auxiliary horizontal deflection that causes modulation of the horizontal scanning speed according to the speed modulation signal SVM.

The wobbling signal generator 22 is connected to the terminal 32, and the wobbling signal SW from the wobbling signal generator 22 is supplied to the velocity modulation deflection coil 31. As described above and as shown in FIG. 7, the wobbling signal SW alternately takes a high level portion and a low level portion for each cycle 1V of the vertical synchronizing signal SV,
The pulse signal has a period of 2V. Due to the action of the velocity modulation deflection coil 31 to which the wobbling signal SW is supplied, the electron beam deflected by the electron beam deflection coil 15 undergoes the vertical deflection action and the horizontal deflection action to reach the inside of the display screen portion 14. As in the case where the green electron beam from the generator 11 is deflected by the landing detection coil 17 shown in FIG. 5,
The deflection according to the wobbling signal SW is also received, and the arrival position of the electron beam for green from the electron beam generating unit 11 inside the display screen unit 14 is the high level portion and the low level portion of the wobbling signal SW. Accordingly, it is changed every 1H.

That is, the wobbling signal SW is the green electron beam from the electron beam generator 11 that is made to reach the inside of the display screen portion 14 by the vertical deflection action and the horizontal deflection action by the electron beam deflection coil 15. The arrival position on the inner side of the display screen portion 14 is received by the supplied deflection coil 31 for velocity modulation,
That is, the wobbling signal SW is changed every 1 V according to the high level portion and the low level portion. Since the change of the arrival position of the green electron beam from the electron beam generator 11 inside the display screen portion 14 is performed under the same state as the state shown in FIGS. 8 and 9 described above. The detailed description is omitted. As a result, when the landing of the green electron beam on the green stripe-shaped phosphors in the large number of segmented phosphors 13 arranged inside the display screen part 14 is in a proper state, the display screen part 14 The brightness of the green striped phosphor is kept constant, while the landing of the green electron beam on the green striped phosphor in the large number of segmented phosphors 13 arranged inside the display screen portion 14 is prevented. When in an improper state, the brightness of the green striped phosphor in the display screen unit 14 is different when the wobbling signal SW takes the high level part and when the wobbling signal SW takes the low level part. It will be.

Display screen section 1 of cathode ray tube 30
A green light detector 25 is disposed on the outer surface side of the light source 4, and the green light detector 25 includes an amplifying unit 26 and a sampling unit 27.
And the comparison unit 28 are sequentially connected, and an output terminal 29 is further connected to the comparison unit 28. The green light detector 25, the amplification unit 26, the sampling unit 27, and the comparison unit 28 are the same as the green light detector 25 and the amplification unit 2 shown in FIG.
6, The same as the sampling unit 27 and the comparison unit 28, and operates similarly to them. Thereby, the comparison unit 2
To the output terminal 29 connected to the display screen unit 14
A comparison output signal SO corresponding to the brightness of the green striped phosphor in is obtained, and based on the state of the comparison output signal SO, in the plurality of segmented phosphors 13 arranged inside the display screen portion 14. The landing state of the green electron beam with respect to the green stripe phosphor is detected.

Even in the cathode ray tube 30, the landing of the blue electron beam on the blue stripe-shaped phosphors in the large number of segmented phosphors 13 arranged inside the display screen portion 14 and the display screen portion 14 are performed. The landing of the red electron beam on the red stripe-shaped phosphors in the large number of segmented phosphors 13 arranged inside the
It should be in the same state as the landing of the green electron beam on the green stripe-shaped phosphors in the large number of segmented phosphors 13 arranged inside the display screen portion 14. Therefore, the comparison output signal S obtained at the output terminal 29
Based on the state of O, the landing state of each electron beam with respect to each of the large number of segmented fluorescent bodies 13 arranged inside the display screen portion 14 is detected.

After the detection of the landing state of the electron beam on the segmented fluorescent body 13 arranged inside the display screen portion 14 in the cathode ray tube 30 is completed, the connection between the terminal 32 and the wobbling signal generation portion 22 is performed. Is cut off and the speed modulation signal forming unit 34 is connected to the terminal 32.

In the above-mentioned example, the landing state of the green electron beam of the plurality of electron beams generated in the cathode ray tube to the green striped phosphor corresponding to that is directly determined. However, it is needless to say that instead of the green electron beam, the landing state of another electron beam with respect to the corresponding section fluorescent body may be directly detected.

[0041]

As is apparent from the above description, the electron beam landing state detecting method according to the present invention is carried out to detect the electron beam landing state with respect to the segmented fluorescent body arranged on the display screen portion of the cathode ray tube. In response to the wobbling signal of the arrival position in the display screen section of the electron beam that is made to reach the display screen section under the deflection action of the electron beam deflection coil, which is required for the detection. The change is to be obtained by supplying a wobbling signal to the velocity modulation deflection means, which the cathode ray tube is equipped with together with the electron beam deflection means, and hence the neck portion of the cathode ray tube. It is not necessary to attach or detach the landing detection coil to or from the vehicle. Therefore, the detection of the landing state of the electron beam with respect to the segmented fluorescent body arranged on the display screen portion of the cathode ray tube eliminates the inconvenience caused by the attachment and detachment of the landing detection coil with respect to the neck portion of the cathode ray tube, and the detection accuracy is improved. It is carried out by an easy and simple work under the condition that it is not necessary to prepare a plurality of types of detection coils and the like.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a cathode ray tube to which an electron beam landing state detection method according to the present invention is applied.

FIG. 2 is a block diagram showing an example of a part of a color image display device and a detection device provided with a cathode ray tube to which an electron beam landing state detection method according to the present invention is applied.

FIG. 3 is a waveform diagram provided for explaining a velocity modulation signal supplied to a velocity modulation deflection coil in an example of a cathode ray tube to which an electron beam landing state detection method according to the present invention is applied.

FIG. 4 is a characteristic diagram used to explain the function and effect of a velocity modulation deflection coil in an example of a cathode ray tube to which an electron beam landing state detection method according to the present invention is applied.

FIG. 5 is a block diagram for explaining the detection of electron beam landing in a conventionally proposed cathode ray tube.

FIG. 6 is a perspective view for explaining detection of electron beam landing in a conventionally proposed cathode ray tube.

FIG. 7 is a waveform diagram provided for explaining a wobbling signal used for detecting electron beam landing in a cathode ray tube.

FIG. 8 is a conceptual diagram provided for explaining a change in the arrival position of the electron beam from the electron beam generation unit in the cathode ray tube inside the display screen unit.

FIG. 9 is a conceptual diagram provided for explaining a change in an arrival position of an electron beam from an electron beam generation unit in a cathode ray tube inside a display screen unit.

[Explanation of symbols]

 11 Electron Beam Generation Section 12 Neck Section 13 Classification Fluorescent Body 14 Display Screen Section 15 Electron Beam Deflection Coil 18 Green Primary Color Signal Supply Section 19 Color Selection Electrode 20 Vertical Deflection Signal Formation Section 21 Horizontal Deflection Signal Formation Section 22 Wobbling Signal Formation Section 25 Green Light Detector 26 Amplifying Section 27 Sampling Section 28 Comparing Section 29 Output Terminal 30 Cathode Ray Tube 31 Velocity Modulation Deflection Coil 32 Terminal 33 Velocity Modulation Signal Forming Section

Claims (3)

[Claims] 1. A display screen section provided with an electron beam generating means, a plurality of sectional fluorescent bodies which emit light when excited by an electron beam from the electron beam generating means, and the display screen section which deflects the electron beam. Electron beam deflecting means for arriving at repetitive scanning in the horizontal and vertical directions, and electron beam deflecting means for arriving at repetitive scanning in the horizontal and vertical directions on the display screen section, at the horizontal scanning speed. For a cathode ray tube provided with a velocity modulation deflecting means arranged to add an auxiliary horizontal deflection that causes modulation, the electron beam causes an auxiliary horizontal deflection that causes modulation of the horizontal scanning velocity by the velocity modulation deflecting means. The display screen section is repeatedly scanned in the horizontal and vertical directions by the electron beam deflecting means without being received. Then, a wobbling signal is supplied to the velocity modulation deflecting means to change the arrival position of the electron beam on the display screen portion in the horizontal direction in accordance with the wobbling signal to display the display. Based on the change state of the luminance in the display screen portion with the change according to the wobbling signal of the arrival position of the electron beam in the screen portion, of the electron beam to the segment fluorescent body arranged in the display screen portion. An electron beam landing state detection method for detecting a landing state. 2. The wobbling signal supplied to the velocity modulation deflecting means is alternately set to a high level and a low level for a predetermined period, and the display screen when the wobbling signal has a high level. The luminance in the display section and the luminance in the display screen section when the wobbling signal takes a low level, respectively, based on the measurement results obtained thereby, for the section fluorescent body arranged in the display screen section. The electron beam landing state detection method according to claim 1, wherein the landing state of the electron beam is detected. 3. A luminance measurement result in the display screen section when the wobbling signal takes a high level and a luminance measurement result in the display screen section when the wobbling signal takes a low level are compared, and 3. The electron beam landing state detection method according to claim 2, wherein the landing state of the electron beam with respect to the segmented fluorescent body arranged on the display screen portion is detected based on the comparison result obtained by the above.