JP2004207933A - Crt display device and projection display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a CRT display device and a projection display device capable of solving the problem in a CRT display device having a convergence adjustment function that a fluorescent body is burned if the display device is left for a long time in a convergence adjustment state. <P>SOLUTION: The display device is provided with a signal selecting circuit which receives a video terminal supplied into an input signal and a pattern signal for convergence adjustment, and selecting any one of the received signals and outputting the selected signal; and a control circuit which controls the signal selecting circuit so as to supply the pattern signal for adjustment to the CRT at the time of convergence adjustment, and to supply the video signal to the CRT, when a time adjusting operation is not conducted for a predetermined period of time in a convergence adjusting state. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a CRT type display device such as a color television set or a projection type television set having a convergence device.
[0002]
[Prior art]
Conventionally, convergence adjustment is required in a projection type television receiver (hereinafter, referred to as a three-tube type projector) including three CRTs (projection tubes) corresponding to R (red), G (green), and B (blue). Yes, digital convergence devices are generally known.
[0003]
For example, a digital convergence device disclosed in Patent Document 1 (Japanese Unexamined Patent Application Publication No. 7-212797) is a digital memory in which M × N adjustment points are arranged on a display screen and convergence correction data corresponding to each adjustment point is stored. And interpolation processing means for creating interpolation data for filling the gaps between the adjustment points with low-pass filter characteristics using the data of the plurality of adjustment points read from the memory, and output from the interpolation calculation means. An auxiliary deflection amplifier for converting data into an analog signal and amplifying the current is provided, and a convergence correction signal is supplied from the amplifier to a convergence yoke attached to a projection tube neck.
[0004]
However, no matter how well the convergence is adjusted, the convergence is deviated when the projector is rotated due to the influence of geomagnetism. To deal with this, a projector has been released that allows the viewer to adjust the convergence by himself.
[0005]
At the time of the convergence adjustment, an image for convergence adjustment is displayed so that convergence at a position corresponding to each adjustment point of digital convergence can be recognized well. A cross or character is displayed. The viewer selects a place with a convergence deviation while watching the displayed adjustment video, and increases or decreases the convergence adjustment data according to the instruction of the viewer, and performs the convergence adjustment.
[0006]
By the way, in order to make the adjuster clearly recognize the deviation of the convergence as described above, it is necessary to display a high-brightness cross hatch image or the like on a black background, and such a high-brightness adjustment image must be displayed for a long time. When the period is displayed, the phosphor in the projection tube may burn.
[0007]
Therefore, when the adjuster starts the convergence adjustment and interrupts the convergence adjustment as it is, or when the consumer leaves the switch in the convergence adjustment mode at the store, the phosphor may be burned.
[0008]
Note that, in a display device using a CRT, even when a still image is displayed for a long time, phosphor burn-in occurs. For example, Patent Document 2 (Japanese Patent Laid-Open No. 4-36889) discloses a measure for preventing such burn-in. There is something like that.
[0009]
In the example described in Patent Document 2, a still image having a large change in luminance is detected, and when the still image continues for a predetermined time or more, the operation of the cathode ray tube is set to a burn-in prevention mode. However, the one described in Patent Document 2 has a disadvantage that an additional circuit such as a line memory is required to detect a still image state, and the circuit configuration is complicated.
[0010]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 7-21779 [Patent Document 2]
Japanese Patent Application Laid-Open No. 4-36889 / 1992
[Problems to be solved by the invention]
In a CRT display device provided with a convergence adjustment function, if the convergence adjustment state is maintained for a long time, the phosphor may burn. An object of the present invention is to provide a CRT display device and a projection display device which solve this problem.
[0012]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a CRT display device having a convergence adjusting device, an input terminal to which a video signal is supplied; an adjusting pattern signal generating circuit for displaying a convergence adjusting pattern; A signal selection circuit for inputting the video signal and the signal from the adjustment pattern signal generation circuit, and selecting and outputting one of the signals; and processing the output signal from the signal selection circuit. A signal processing circuit for supplying to the CRT; supplying the adjustment pattern signal to the CRT at the time of convergence adjustment; and supplying the video signal to the CRT when there is no adjustment for a predetermined time in the convergence adjustment state. And a control circuit for controlling the signal selection circuit.
[0013]
According to a fifth aspect of the present invention, there is provided a CRT type display device having a convergence adjusting device, an input terminal to which a video signal is supplied; an adjusting pattern signal generating circuit for displaying a convergence adjusting pattern; And a signal selection circuit for inputting a video signal from the device and a signal from the adjustment pattern signal generation circuit, and selecting and outputting one of the signals; and processing an output signal from the signal selection circuit. A signal processing circuit for supplying the CRT with the pattern signal for adjustment at the time of convergence adjustment, and a brightness control signal for the video signal processing circuit when there is no adjustment for a predetermined time in the convergence adjustment state. A control circuit for supplying a signal and reducing the brightness of the signal supplied to the CRT. It is an RT-type display device.
[0014]
According to the above invention, when the adjuster leaves the place for a long time during the convergence adjustment, it is necessary to display the video signal from the input terminal 11 or switch to reduce the brightness of the display screen. , CRT phosphor can be prevented from burning.
[0015]
The invention according to claims 9 and 11 is a projection display device having the above-described burn-in prevention function.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a CRT display device according to an embodiment of the present invention, and is a block diagram showing an example of a three-tube projector.
[0017]
In FIG. 1, reference numeral 11 denotes an input terminal to which a video signal S1 is input, to which a video signal obtained by subjecting a television broadcast signal to reception processing by a tuner or a video signal provided from outside such as a VTR is input. The video signal S1 is supplied to the selection circuit 12, to which the video signal S2 for generating a convergence adjustment pattern is also input from the adjustment pattern signal generation circuit 13.
[0018]
The selection circuit 12 selectively outputs either the video signal S1 or the video signal S2 in response to a command from the microprocessor 15, and a command from an input device 14 such as a remote controller is supplied to the microprocessor 15. It is supposed to be. The video signal S1 or S2 selected by the selection circuit 12 is supplied to a video signal processing circuit 16, and the video signal processing circuit 16 converts the video signal into RGB signals based on the supplied video signal, and amplifies the signals. 173 respectively.
[0019]
The RGB signals amplified by the amplifier circuits 171, 172, and 173 are supplied to projection tubes 181, 182, and 183 corresponding to the three primary colors, respectively, and projected on the rear surface of the screen 19 via an optical system including a projection lens and the like. As a result, the projected images from the projection tubes 181, 182, and 183 are superimposed and displayed on the screen 19, and a color image is projected. This image is visually recognized by the viewer from the front side of the screen 19.
[0020]
On the other hand, the video signal selected by the selection circuit 12 is further supplied to a synchronization separation circuit 20, where the synchronization signal is separated and extracted. This synchronization signal is supplied to the main deflection signal generation circuit 21. The horizontal (H) and vertical (V) main deflection signals generated by the main deflection signal generation circuit 21 are supplied to main deflection coils mounted on the necks of the RGB projection tubes 181 to 183. The main deflection signal generation circuit 21 generates horizontal and vertical timing signals synchronized with the timing of each main deflection, and supplies the signals to the digital convergence circuit 22.
[0021]
Incidentally, a reflecting mirror is appropriately arranged between the three projection tubes 181 to 183 and the screen 19, and the image light projected from each of the projection tubes 181 to 183 is turned back to be guided to the screen 19. The device is made thinner. The three projection tubes 181, 182, and 183 are arranged such that the R and B projection tubes 181 and 183 are symmetrically disposed about the G projection tube 182, respectively. The positional relationship between the tubes is different as shown in FIG. For this reason, even in the same projection tube, the projection distance is different between the central part and the peripheral part of the screen. In this state, the projected images of the respective colors of RGB do not overlap correctly, and distortion occurs.
[0022]
The digital convergence circuit 22 adjusts convergence in response to such a problem. The convergence circuit 22 receives a command from the microprocessor 15 and receives a synchronization signal from the main deflection signal generation circuit 21. Is entered. Then, horizontal and vertical auxiliary deflection signals (six types) corresponding to the respective projection tubes 181 to 183 are generated, and these six types of auxiliary signals are current-amplified by amplifier circuits 231 to 236, respectively. The signals are supplied to input terminals of horizontal and vertical auxiliary deflection coils 241 to 243 provided on the neck of the 183. Further, a timer circuit 25 is connected to the microprocessor 15.
[0023]
Next, the digital convergence circuit 22 of the present invention will be described in detail with reference to FIGS. FIG. 2 shows a display screen at the time of convergence adjustment. A cross hatch pattern composed of vertical lines and horizontal lines is displayed on the screen based on a signal from the adjustment pattern signal generation circuit 13, and each intersection of the cross hatch is displayed. An adjustment point is set at the position, and the convergence correction amount at each adjustment point is stored in the nonvolatile memory of FIG.
[0024]
In FIG. 3, the digital convergence circuit 22 has a nonvolatile memory 30. The nonvolatile memory 30 stores data indicating the convergence correction amount of each adjustment point, and the data is stored in the nonvolatile memory 30. The data is respectively transferred to the memory 32 by the control signal 31 from the microprocessor 15.
[0025]
Based on the vertical and horizontal scanning timing supplied from the main deflection signal generating circuit 21, the timing signal generating circuit 34 controls the address and readout of the memory 32, and the control signal necessary for the interpolation operation unit 35. Occurs. The convergence data is read from the memory 32 at a predetermined timing synchronized with the scanning, and the data read from the memory 32 is supplied to the interpolation calculation unit 35.
[0026]
The interpolation calculation unit 35 performs an interpolation calculation on the correction amount of the entire screen from the convergence data of each adjustment point as an input, and outputs the calculated convergence correction amount to the D / A converters 361 to 366 in accordance with the scanning timing. I do. The convergence correction amount becomes an analog signal at the D / A converters 361 to 366, but is still a step-like waveform including a harmonic component. Therefore, after the harmonic components are removed by the LPFs 371 to 376, the digital convergence circuit 22 outputs the signal.
[0027]
Next, a convergence adjustment operation in the projector including the digital convergence circuit 22 will be described.
[0028]
When the microprocessor 15 receives a command to start convergence adjustment via the input device 14, the microprocessor controls the selection circuit 12 to select a signal from the adjustment pattern signal generation circuit 13. Then, an image for adjustment (for example, a cross hatch pattern) as shown in FIG. 2 is displayed on the screen. The coordinator instructs the microprocessor 15 via the input device 14 for the convergence adjustment position. The microprocessor 15 controls the adjustment pattern generation signal generation circuit 13 to display some marker (square P in the figure) near the adjustment point designated by the adjuster.
[0029]
In this state, the viewer adjusts the convergence of the marker position while watching the screen. When the microprocessor 15 receives the instruction to execute the adjustment from the viewer, the timer 24 starts the time counting operation and increases or decreases the data value of the memory 32 in the digital convergence circuit 22. As a result, the convergence of the part indicated by the marker P is adjusted according to the viewer's intention.
[0030]
To adjust the convergence, the data in the memory 32 is read out, separated into six types of correction data in the horizontal and vertical directions of R, G, and B, and D / A conversion circuits (361 to 366) and LPFs (371 to 376). The convergence correction waveform is supplied to the horizontal and vertical auxiliary deflection coils 241 to 243 via the..., And is corrected to an optimum value by increasing or decreasing the data in the memory 32, and the corrected data is newly stored in the memory 32. It is memorized.
[0031]
When the viewer gives the instruction of the adjustment completion to the microprocessor 15, the microprocessor 15 causes the data in the memory 32 to be stored in the nonvolatile memory 30. Then, the selection circuit 12 is controlled so that the selection circuit 12 displays the video signal supplied to the input terminal 11. Thus, a series of adjustment operations is completed.
[0032]
On the other hand, after entering the convergence adjustment state, the microprocessor 15 resets the timer 10 every time the coordinator performs the final action. An interrupt for a predetermined time has elapsed. By this interrupt processing, the microprocessor 15 controls the selection circuit 12 to switch to display the video signal from the input terminal 11 without waiting for the adjustment completion instruction from the adjuster. Accordingly, it is possible to prevent the cross hatch pattern P from being displayed for a long time, and to prevent burn-in of the phosphor.
[0033]
The final action performed by the coordinator is, for example, when the convergence adjustment of a predetermined position is completed or when the convergence of a predetermined color out of the R, G, and B adjustments is completed, the coordinator adjusts the convergence. , And the timer 25 is reset each time a predetermined adjusting action ends. Therefore, when the adjuster is nearby and performing the convergence adjustment work, the adjustment pattern is sequentially displayed in response to the instruction of the adjuster.
[0034]
If the coordinator leaves the place for a long time while the convergence adjustment is being performed, the timer 25 switches to display the video signal from the input terminal 11 when the predetermined time is counted. , CRT phosphor can be prevented from burning.
[0035]
Further, when forcibly returning to the video display state due to interruption by the timer 25, message information is output from the on-screen display circuit that performs channel display and the like, and the fact that the convergence adjustment state has been switched to the normal video display mode. May be displayed.
[0036]
Next, a second embodiment of the present invention will be described with reference to FIG. The difference from the embodiment of FIG. 1 is that a control signal for controlling the brightness of the display screen is supplied from the microprocessor 15 to the video signal processing circuit 16 via the signal line 40. That is, after entering the convergence adjustment state and a predetermined time has elapsed, the timer 25 interrupts the microprocessor 15 for the elapse of the predetermined time.
[0037]
By this interrupt processing, the microprocessor 15 outputs a control signal for reducing the brightness to the video processing circuit 16. The signal for brightness control is, for example, a signal for contrast control or a signal for brightness control.
[0038]
Thereby, the brightness of the displayed convergence adjustment pattern is reduced, and burn-in can be prevented. Then, when the adjuster starts the adjusting action again, the microprocessor 15 supplies the contrast control data or the brightness control data to the video signal processing circuit 16 so as to return the once darkened screen to the original brightness. . Thus, the adjuster can restart the convergence adjustment again on the bright screen.
[0039]
In the above description, the timer 25 is provided outside the microprocessor 15 for simplification of the description, but a timer or a clock function built in the microprocessor 15 may be used.
[0040]
As described above, according to the present invention, after the adjustment pattern is displayed for the convergence adjustment, the control is performed such that the image display state is automatically returned to when the predetermined time has elapsed, or the screen brightness is reduced. This prevents burning of the phosphor, and can be modified regardless of the example described in the embodiment.
[0041]
【The invention's effect】
As described above, according to the present invention, even when the convergence adjustment state is left, the burn-in of the projection tube can be prevented.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a projector according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing a display example of a convergence adjustment pattern according to an embodiment of the present invention.
FIG. 3 is a circuit diagram illustrating a configuration of a digital convergence circuit used in one embodiment of the present invention.
FIG. 4 is a block diagram showing a configuration of a projector according to another embodiment of the present invention.
[Explanation of symbols]
11 video signal input terminal 12 selection circuit 13 adjustment pattern signal generation circuit 14 input device 15 microprocessor 16 video signal processing circuits 171-173 amplification circuits 181-183 projection tube 19 screen 20 screen synchronization Separation circuit 21 Main deflection signal generation circuit 22 Digital convergence circuits 231 to 236 Amplification circuits 241 to 243 Auxiliary deflection coil 25 Timer circuit 30 Nonvolatile memory 32 Memory 35 Interpolation operation circuit 40 line

Claims (12)

In a CRT display device having a convergence adjusting device,
An input terminal to which a video signal is supplied,
An adjustment pattern signal generation circuit for displaying a convergence adjustment pattern;
A video signal from the input terminal and a signal from the adjustment pattern signal generation circuit, and a signal selection circuit for selecting and outputting one of the signals;
A signal processing circuit that processes an output signal from the signal selection circuit and supplies the processed signal to the CRT;
A control circuit that supplies the adjustment pattern signal to the CRT at the time of convergence adjustment, and controls the signal selection circuit so as to supply the video signal to the CRT when there is no adjustment for a predetermined time in the convergence adjustment state. A CRT type display device comprising: A timer circuit for detecting that the predetermined time adjustment is not performed, the timer circuit starts a timing operation at the start of the convergence adjustment, and the control circuit is configured to perform the timer operation when the timer circuit has counted a predetermined time. The CRT type display device according to claim 1, wherein the signal selection circuit is controlled so as to supply a video signal to the CRT. The timer circuit measures a predetermined time, and has an on-screen circuit that outputs message information when the video signal is switched to a display state, superimposes the message information on the video signal, and displays an image from the convergence adjustment state. 3. The CRT display device according to claim 2, wherein a message indicating that the mode has been switched is displayed. 3. The CRT type display device according to claim 2, wherein the timer circuit resets a timing operation when predetermined convergence adjustment is completed. In a CRT type display device having a convergence adjusting device, an input terminal to which a video signal is supplied;
An adjustment pattern signal generation circuit for displaying a convergence adjustment pattern;
A video signal from the input terminal and a signal from the adjustment pattern signal generation circuit, and a signal selection circuit for selecting and outputting one of the signals;
A signal processing circuit that processes an output signal from the signal selection circuit and supplies the processed signal to the CRT;
A signal for supplying the adjustment pattern signal to the CRT at the time of convergence adjustment, and supplying a brightness control signal to the video signal processing circuit when there is no adjustment for a predetermined time in the convergence adjustment state, and supplying the signal to the CRT. And a control circuit for reducing brightness of the CRT display device. A timer circuit for detecting that the predetermined time adjustment is not performed, the timer circuit starts a timing operation at the start of the convergence adjustment, and the control circuit is configured to perform the timer operation when the timer circuit has counted a predetermined time. 6. The CRT type display device according to claim 5, wherein a brightness control signal is supplied to the video signal processing circuit to control the CRT screen to be dark. 7. The CRT display device according to claim 6, wherein the control circuit controls the CRT screen to be bright when the convergence adjustment is performed again after the predetermined time has elapsed. 7. The CRT type display device according to claim 6, wherein the timer circuit resets a timing operation when predetermined convergence adjustment is completed. In a projection display device having three projection tubes corresponding to R (red), G (green), and B (blue),
An input terminal to which a video signal is supplied,
An adjustment pattern signal generation circuit for displaying a convergence adjustment pattern;
A video signal from the input terminal and a signal from the adjustment pattern signal generation circuit, and a signal selection circuit for selecting and outputting one of the signals;
A signal processing circuit that processes an output signal from the signal selection circuit and supplies the processed signal to the CRT;
Sub-deflection coils respectively provided in the projection tube,
A convergence circuit that generates a convergence correction signal and supplies a convergence correction signal to the sub deflection coil during convergence adjustment;
When the convergence adjustment is performed, the adjustment pattern signal is supplied to each of the projection tubes, and the signal selection circuit is controlled so as to supply the video signal to the projection tubes when there is no adjustment for a predetermined time in the convergence adjustment state. A projection display device comprising a control circuit. 10. The projection display device according to claim 9, further comprising an on-screen circuit that outputs message information indicating that the display state has been switched to the display state of the video signal when there is no adjustment operation for a predetermined time in the convergence adjustment state. . In a projection display device having three projection tubes corresponding to R (red), G (green), and B (blue),
An input terminal to which a video signal is supplied,
An adjustment pattern signal generation circuit for displaying a convergence adjustment pattern;
A video signal from the input terminal and a signal from the adjustment pattern signal generation circuit, and a signal selection circuit for selecting and outputting one of the signals;
A signal processing circuit that processes an output signal from the signal selection circuit and supplies the processed signal to the CRT;
A sub deflection coil provided in each of the projection tubes,
A convergence circuit that generates a convergence correction signal and supplies a convergence correction signal to the sub deflection coil during convergence adjustment;
At the time of convergence adjustment, the adjustment pattern signal is supplied to each of the projection tubes, and when there is no adjustment operation for a predetermined time in the convergence adjustment state, a brightness control signal is supplied to the video signal processing circuit, and each of the projection tubes is supplied. And a control circuit for reducing the brightness of a signal supplied to the projector. The control circuit, when there is no adjustment action for a predetermined time in the convergence adjustment state, while supplying a brightness control signal to the video signal processing circuit to reduce the brightness of the signal supplied to each of the projection tubes, 12. The projection display device according to claim 11, wherein when the convergence adjustment is performed again after a predetermined time has elapsed, the screen is controlled to be bright.

Images