JPH02234591A - Color purity adjusting device - Google Patents

Abstract

PURPOSE:To automate the adjustment of the color purity by adjusting the color purity in a center part through the adjustment of the current for a color purity adjustment coil in response to the detection of an optical sensor. CONSTITUTION:A CPU 12 applies calculation in response to the detected value of an optical sensor 10 obtained from an A/D converter 11 and calculated offset currents IHF, IVF are stored in a memory 13. Moreover, current supply circuits 8, 9 output respectively currents IH1, IH2 and IV1, IV2 in response to the currents IHF, IVF. When a switch 15 is thrown to the position (b) and the optical sensor 10 is made approached or pressed in the middle part of a display face 1a, the above series of operations are entirely automated, the currents IH1, IH2 and IV1, IV2 flow to control the device in the just landing state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color purity adjusting device for adjusting the color purity of the central portion of the display surface of a color cathode ray tube.

[Conventional technology]

FIG. 6 is a side view showing a conventional color purity adjustment device. In the figure, 1 is a color cathode ray tube (hereinafter referred to as CRT).
, 1a is the display surface of the CRT, 1b is the neck of the CRT 1,
2 is a deflection yoke provided on the neck portion 1b; 3a, 3b;
is a purity magnet provided in the neck part 1b,
As shown in FIG. 7, it has a ring shape, and N-S magnetic poles are magnetized at opposing positions. 4 is a shadow mask provided close to the display surface 1a within the CRT 1.

Figure 8 shows the beerity magnet 3a. 3b and the electron beam passing through the neck portion 1b.
R, 5c. 5B are electron beams emitted from R (red), G (green), and B (blue) electron guns (not shown), respectively.

FIG. 9 shows the relationship between the phosphor coated on the display surface 1a and the electron beam, where 5 is the electron beam and 6 is the dot-shaped fluorescent material. It is the body. (3) in the same figure shows a just landing state, and (B) in the same figure shows a mislanding state.

Next, the operation will be explained. An electron beam 5n is emitted from an electron gun provided in the neck portion 1b of the CRT 1.
After being deflected in the horizontal and vertical directions by the deflection yoke 2, the light beams 5a and 5a pass through the shadow mask 4 and collide with the R, G, and H phosphors 6 provided on the inner surface of the display surface 1a. As a result, the phosphors 6 emit light in various colors, and the display surface 1
A color image is displayed in a.

At this time, it is necessary to achieve a just-landing state in which the center of the electron beam 5 coincides with the center of the phosphor 6, as shown in Figure 9, and a mis-landing state in which the two centers do not coincide, as shown in Figure 9 (B1). In this case, part of the electron beam 5 hits the adjacent phosphor 6 of a different color, causing color unevenness in the center of the display surface 1a, resulting in poor color purity.

In order to correct such poor color purity, purity magnets 3a and 3b are provided.

As shown in Fig. 8, two virility magnets 3
a. 3b clockwise or counterclockwise,
- By adjusting the position of the SliB pole, the magnetic field received by the electron beams 5n, 5a, 5B becomes the vector sum of the magnetic fields generated by the beauty magnets 3a, 3b, respectively. As a result, the electron beams 5R, 5
G and 5B receive deviations based on Fleming's left hand rule. By adjusting the amount and direction of this deviation,
The just landing state shown in FIG. 9(A) can be obtained.

[Problem to be solved by the invention]

Since the conventional color purity adjustment device is configured as described above, the electron beam 5 is deflected by the vector sum of the abrasive fields generated by the two beauty magnets 3a and 3b. The adjustment work of moving the electron beam 5 by the target amount in the target direction by moving the virility magnets 3a and 3b requires considerable skill, and even when automatic adjustment is performed, the virility magnets 3a and 3b
The equipment that moves the CRT is complicated and expensive, and when a general user uses a CRT, the direction of the air acting on the CRT changes when the CRT is turned, causing the electron beam to be deflected. However, in such a case, there are problems such as difficulty in readjusting the color purity on the user side.

This invention was made to solve the above-mentioned problems, and by electrically adjusting the color purity in the center of the display surface, it facilitates automatic adjustment and also allows for adjustment on the user's side. It is an object of the present invention to provide a color purity adjustment device that can perform the following functions.

[Means to solve the problem]

The color purity adjustment device according to the present invention includes two sets of coils that adjust the horizontal and vertical positions of electron beams in the neck of a CRT, and detects the brightness of the display surface using an optical sensor. The current to be passed through the coil is calculated based on the value.

[For production]

The color purity adjustment device according to the present invention can automatically adjust the color purity by passing the calculated current through the two sets of coils, and also allows the user to perform adjustment by storing the current value. becomes possible.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In FIGS. 6 and 2, the same parts as in FIGS. 6 and 8 are given the same reference numerals, and their explanations will be omitted. 7 is neck part 1
The color purity adjustment coil section provided in the color purity adjustment coil section b includes a first coil 7a7b for horizontal adjustment and second coils 7c and 7d for vertical adjustment. 8 is the first coil 7a,
7b is a current supply circuit that supplies an adjustment current; 9 is a second
10 is a light sensor using a COD camera or the like provided close to the center of the display surface 1a; 11 is a light sensor 10;
An A/D converter 12 converts an analog detected value into a digital value, and an A/D converter 12 performs a predetermined calculation, which will be described later, based on the detected value obtained from the A/D converter 11. ．． In this embodiment, the CPU 12 is used as a calculation means that calculates the current supplied to rb+7c+7a and also performs predetermined control on other circuits. 13 is C
14 is a bus line connecting the CPU 12 and other circuits; 15 is a switch for selecting an adjustment mode; 16 to 19 are switches in manual adjustment mode; A switch 20 switches the current flowing through the first and second coils 7a to 7d in a horizontal positive or negative direction and a vertical positive or negative direction, and 20 is an input/output for transmitting input signals from each of the above-mentioned Suinochis 15 to 19 to the CPU 12. It is a circuit.

Next, the operation will be explained. In FIG. 2, the magnetic field that deflects the electron beams 5yt, 5c, 5s is generated by the current flowing through the first coil 7a}γb for horizontal adjustment and the second coil 7c, 7d for vertical adjustment. It is determined. First coil 7a, 7b and second coil 7
cs7a are connected in directions such that the magnetic fields generated by the currents supplied from the current supply circuits 8 and 9 do not cancel each other out.

As a result, the electron beams 5n,
5o. 5B can be deflected to a horizontal target position. Along with this, the second coils 7c, 7dl
The electron beam SR. 5a, 5B can be deflected to a vertical target position. That is, instead of the above-described mechanical adjustment for adjusting the rotation angle of the rotation angles of the rotational magnets 3a and 3b, the same function is performed by electrical adjustment.

Next, the measurement of color purity will be explained. Now, suppose that when a monochrome raster of, for example, R is displayed on the display surface 1a, the mislanding state shown in FIG. 9 [B] occurs.

At this time, the current should be applied to each of the first coils 7a and 7b.
If i is IHI * IH2 + offset current is INF, Ill ” IHF + △l ・・・・・・・・・・・・・・・
...... (1) IH2 = IHF - △■ ・
・・・・・・・・・・・・・・・・・・ D). At this time, the output characteristics of the optical sensor 10 when the offset electric current F=o is as shown in FIG. In FIG. 3, if the output values of the optical sensor 10 when the currents IHI + IH2 are applied are p1, p, ., then the horizontal mislanding amount AH can be found as follows. The above (11. f
By changing the value of offset current IMF' in equation 21,
As shown in Figure 4, there is a point where pi = p2,
At this time, the horizontal mislanding amount AH=0. Using the offset lightning current IHF at this time, +11
, +2) From the formula, the current IHI . The value of IH2 is obtained.

Similarly, for the vertical mislanding amount AV, IVI ” xvr + △Iv ・・・・・・・・・
...... (4) IV2 = IVF - ΔIV
・・・・・・・・・・・・・・・・・・Offset current 1 at the point where the vertical mislanding amount Av = O by changing the offset current IMF, obtained by (5)
By obtaining v, it is possible to find the current ``/L + IV2'' flowing through the coil 7c+7d of K2.

The above calculation is performed in the CPU 12 according to the detected value of the optical sensor 10 obtained from the A/D converter 11, and the calculated offset current IHF. The value of IMF is stored in memory 13. Further, the current supply circuits 8 and 9 each have an offset current IMF'. Current I according to IMF'
HL+! }12 and IML r IV2.

Next, each adjustment mode will be explained. When the mode selection switch 15 is closed to the contact a side, the non-adjustment mode is entered.

In this case, memory 13. The above offset current IM
F' l xvF is read. In response, the current supply circuit 8 supplies the first coils 7a, 7b with (11. (21
Electrician old according to the formula. In addition to supplying IH2, the current supply circuit 9 supplies +41 to the second coils 7c and 7d.
．． (Control is performed to supply currents IVI and IV2 according to Equation 51. As a result, the color purity at the center of the display surface 1a becomes the just-landing state shown in FIG. 9(A).

Next, when the switch 15 is closed to contact b, the automatic adjustment mode is entered. In this case, if the optical sensor 10 is placed close to or pressed against the center of the display surface 1a, the series of operations described above will be performed automatically, and each current 1tn. ■H2.
Ivt. IV2 flows and is controlled to a just landing state.

If the switch 15 is closed to contact C, the manual adjustment mode is entered. In this case, the adjustment can be made visually by operating the switches 16 to 19 without using the optical sensor 10. That is, switches 16, 17 are used to adjust the offset current IMF in the positive or negative direction, and switches 18.
19 to adjust the offset current IVF in the positive or negative direction, the optimal offset current IFfF'
．． Find IMF and calculate the current IHI * IH2 r
IVI + I'V2 can be obtained.

The control operations in each of the adjustment modes described above are all programmed and executed by the CPU 12K. FIG. 5 shows a flowchart of the above program. In FIG. 5, first, in step ST(1), the state of the mode selection switch 15 is checked to find out which mode is selected. If the non-adjustment mode is selected, step ST
(Proceeding to 21, the offset current IHFtIVF stored in the memory 13 is read out, and the current value is set in the next step ST (31, the process is completed by setting it in the current supply circuit 8.9.)

As a result, current supply circuits 8 and 9 supply current Hl + I
H2 TIvl+IV2 is output.

If automatic adjustment mode is selected, step ST (4)
Proceeding to step 1, first, offset current IHF. After setting the IVF to zero, in step ST (5), the above (1),
(21. (Calculate the horizontal mislanding amount AH using equation 31. Next, it is checked in step ST (61) whether this horizontal mislanding amount AH is within a predetermined tolerance value. Horizontal mislanding If the scene A exceeds the allowable value, the process proceeds to step ST (71), where the offset current HF such that the horizontal mislanding amount AH = O is obtained, and that value is passed to the next step ST t
The current supply circuit 8 is set in step 81. This causes the current I
After HI*112 is passed and the adjustment is performed, the process returns to step ST (51K) and calculates the horizontal mislanding amount A■ after the above adjustment again.
~8T (81) is performed until the horizontal misland ink amount AH falls within the allowable value in step ST(61), and when it falls within the allowable value, the process proceeds to step STf91.

In step ST (91), the vertical mislanding amount Av is determined using the formulas +41, +51, etc., and it is checked in step ST (10) whether the value is within a predetermined tolerance.

Then, step ST(u) and step ST(12)K are performed until the vertical mislanding amount AV falls within the allowable value.
From this, an offset current IVF such that the vertical mislanding amount Ay = 0 is obtained, that value is set in the current supply circuit 9, and the operation of flowing the current IVI*IV2 is repeated. If the vertical mislanding amount Av falls within the allowable value, the process proceeds to step ST (13), and the offset currents INF and IVF at that time are stored in the memory 13.
Write this and finish.

If manual adjustment mode is selected, step 8 T
Proceeding to (14), first, the offset current design HF*IVF is read from the memory 13. Next K step ST
In step (15), check the states of switches 16-19. If the switch 16 is turned on, step ST (16)
Then, an offset current IMF is obtained by adding a predetermined current amount ΔIH to the offset current IMF read above. If the switch 17 is turned on, step ST
Proceeding to (17), the above read offset current IM
F to a predetermined amount of current I. Offset current I after subtracting
Find MF. Similarly, switch 18 or 19 is turned OFF.
If N, step ST (1.8) or ST
Proceed to (19) to determine the offset current IV read above.
An offset current IVF is obtained by adding or subtracting a predetermined current amount ΔIv from F.

Step ST (20) according to the offset current IMF determined in step ST (16) or ST (17).
Accordingly, the current supply circuit 8 supplies currents IHI and IH2.
flow. Also, step ST(18) or ST(19
) The current IVl is supplied from the current supply circuit 9 in step ST(21) according to the offset current IVF obtained in
+ Stream IV2. Next, in step ST(2)),
If it is determined that the manual adjustment mode is subsequently selected, the process returns to step ST(15) and switches 16 to
Offset current INF *
Seek IVF. If the optimum condition is obtained by visual inspection of the set text, the operations of the switches 16 to 19 are completed, and the manual adjustment is completed.

In the above embodiment, the horizontal mislanding amount A. Although equation (3) is used for the calculation, it may be a simple difference or ratio between P1 and P2, and many changing equations can be considered, so it can be generalized as horizontal mislanding amount AH = F (PL.P2). The same applies to the vertical mislanding amount AV.

Further, in the above embodiment, digital control is performed by the CPU 12, but it can also be realized by an analog circuit.

〔Effect of the invention〕

As described above, according to the present invention, the center color purity adjustment is performed by adjusting the current of the color purity adjustment coil according to the detection by the optical sensor, so that the adjustment can be easily automated. In addition, since the measurement is performed using the optical sensor K, highly accurate adjustment is possible. Further, manual adjustment can be easily performed by operating a switch, and therefore, it is possible to correct a mislanding condition at the center of the CRT due to the influence of the earth's magnetic field without using special adjustment skills on the user's side.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a color purity adjustment device according to an embodiment of the present invention, Fig. 2 is a block diagram of a coil for color purity adjustment of the same device, and Fig. 3 is a diagram of the output characteristics of the optical sensor of the same device. , Fig. 4 is a diagram of the output characteristics of the optical sensor when the offset current of the device is considered, Fig. 5 is a flowchart showing the operation of each adjustment mode of the device, and Fig. 6 shows a conventional color purity adjustment device. 7 is a perspective view of the pearity magnet of the same device, FIG. 8 is a front view of the pearity magnet, and FIG. 9 is a configuration diagram.
The figure is a front view of the main parts for explaining the landing of the electron beam. 1 is a color cathode ray tube, 1a is a display surface, 1b is a neck part,
5. SR. 5c and 5B are electron beams,
7a+7b are first coils, 7c and 7d are second coils, 8 and 9 are current supply circuits, 10 is a light sensor, and 12 is C
In addition, in the figures, the same reference numerals indicate the same or corresponding parts. 1H2 [141 Figure Figure 1A1 Procedural amendment (voluntary)

Claims (1)

[Claims] A first coil provided at the neck of the color cathode ray tube to adjust the horizontal position of the electron beam; and a second coil provided at the neck of the color cathode ray tube to adjust the vertical position of the electron beam. an optical sensor for detecting the brightness of the display surface of the color cathode ray tube; and an arithmetic means for performing a predetermined calculation based on the detected value of the optical sensor to determine a current value to be passed through the first and second coils. and a current supply circuit that supplies current to the first and second coils with a magnitude corresponding to the calculation result of the calculation means.