JPH06110396A - Crt display device and its power source control method - Google Patents

Abstract

PURPOSE:To prevent a power from being consumed wastefully and to extend the service life of a CRT by performing the on/off control of a power circuit when the presence/absence of a video signal is detected. CONSTITUTION:A CPU 15 is equipped with a main power source control means which controls a main power source 4 so as to perform the on/off control on the power circuit 9 when a video signal detection circuit detects the presence/ absence of a blue video signal, a first timer means which clocks the off state of the power circuit 9, and an auxiliary power source control means which controls an auxiliary power source 5 so as to turn off a heater 14 after the lapse of a time period set in advance on the first timer means. Also, the main power source control means is equipped with a second timer means which clocks a state where no signal exists, a power circuit off means which turns off the power circuit 9 after the lapse of the time period set in advance on the second timer means, and a blanking signal generating means which supplies a video blanking signal to a video circuit 8 for only a prescribed time period when the presence of a video signal in the video signal detection circuit is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CRT display device and a power supply control method thereof, and more particularly to a CRT display device.
The present invention relates to power supply control for extending the life of the RT.

[0002]

2. Description of the Related Art A CRT display device is used to display an image of a video signal by being connected to a main device such as a host computer which generates a synchronizing signal and a video signal. In this case, it is recommended that the power supply of the CRT display device be independent of the power supply of the computer. This is because when the power of the CRT display device is taken from the computer, the power switch of the computer may be over capacity. Further, the CRT display device and the computer are often installed in mutually separated places.

Under such circumstances, some CRT display devices have been proposed in which the power supply of the CRT display device is configured to be on / off controlled based on a signal from a computer.

Japanese Unexamined Patent Publication No. 64-33586 discloses a device that detects the presence or absence of a video signal from a computer and controls the power supply of a CRT display device based on the detection result. However, according to this power supply control method, when the CRT intentionally displays a uniform black image, there is no video signal, and even in this case, the power supply of the CRT display device is mistaken. The inconvenience of being turned off occurs.

Further, in Japanese Patent Laid-Open No. 60-1982 and Japanese Patent Laid-Open No. 1-257893, the presence or absence of a sync signal from a computer is detected, and C is detected based on the detection result.
What controls on / off the power of an RT display device is described. However, according to this power supply control method, since the synchronization signal is constantly sent from the computer, unless the power of the computer is turned off or the connection with the CRT display device of the computer is cut off.
There is an inconvenience that the power of the CRT display device cannot be turned off.

On the other hand, in order to prevent the phosphor applied to the display surface of the CRT from burning, when the same display is performed on the CRT for a certain period of time, a uniform black image display is switched. is there. To switch the display to a black image like this, for example, “Screen Saver [Screen Save
This is often done by application software called "er]". However, when the "screen saver" operates in this way, the display surface of the CRT is difficult to distinguish from the case where the power of the CRT display device is turned off. On the other hand, even if the "screen saver" is activated, the power of the CRT display device is not turned off. Therefore, the CRT
The display device may be left for a long time with the power on. In this case, power is wasted, and the heater provided in the CRT remains on, which shortens the life of the CRT.

[0007]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the above-mentioned inconvenience in a CRT display device in which a "screen saver" is made to work.

[0008]

According to the present invention, first, a CRT which is connected to a main unit for generating a synchronizing signal and a video signal to display an image of the video signal is provided.
Aimed at a display device. This CRT display device processes a synchronization circuit from a power supply circuit including a main power supply and an auxiliary power supply, a power circuit driven by the main power supply, including a high voltage circuit, a deflection circuit and a video circuit, and a synchronization signal from the main device. And a synchronization processing circuit for giving the processed synchronization signal to the high-voltage circuit and the deflection circuit; and a video signal detecting means for detecting the presence or absence of a video signal from the main device, and processing and processing the video signal. A video input processing circuit for applying a video signal to the video circuit, an anode to which a high voltage DC voltage is applied from the high voltage circuit, a deflection yoke to which a deflection current is applied from the deflection circuit, and a cathode drive signal from the video circuit. A cathode ray tube and a CRT having a heater to which an electric current is supplied from the auxiliary power source. In any of the first and second aspects described below, the CRT display device according to the present invention has the above-mentioned elements in common.

In the CRT display device according to the present invention, in the first aspect, the main power supply is controlled so as to turn on / off the power circuit when the video signal detecting means detects the presence / absence of the video signal. Main power control means for
At least first timer means for measuring a time period in which the power circuit is turned off, and the auxiliary power source is controlled so as to turn off the heater after a time period preset in the first timer means has elapsed. And an auxiliary power source control means.

According to the first aspect described above, when the "screen saver" operates and the CRT displays a uniform black image, that is, when there is no video signal, the power circuit is first turned off. If this state continues and the time period preset in the first timer means elapses, then the heater is turned off. Therefore, according to the present invention, it is possible to reduce the wasteful consumption of electric power and extend the life of the CRT. Further, if a video signal is detected before the heater is turned off after the power circuit is turned off, it is possible to quickly return to the normal image display state.

In the above-mentioned first aspect, the main power supply control means is provided with a second timer means for measuring a state in which the video signal is absent, and after a lapse of a time period preset in the second timer means. It is preferable to provide a power circuit off means for turning off the power circuit. As a result, even if the "screen saver" is activated and there is no video signal, the power circuit is not immediately turned off.
When the application software intentionally displays a uniform black image, the power circuit can be prevented from being turned off accidentally. As a result, it becomes possible to perform fine power supply control.

[0012] Preferably, the time period preset in the first timer means is variable. As a result, it is possible to perform power supply control that meets the operator's request.

Further, the main power supply control means, when the video signal detection means detects the presence of the video signal,
It is preferable that the video circuit includes a blanking signal generating means for applying a video blanking signal for a predetermined time period. As described above, when a video signal is detected after the power circuit is turned off and before the heater is turned off, the normal image display state is restored, but at the moment of this restoration, normally, The image is distorted. As described above, when the video blanking signal is applied for a predetermined time period such as 2 seconds at the moment of restoration, it is possible to prevent the image distortion from being shown to the operator.

In the CRT display device according to the second aspect of the present invention, in addition to the common elements described above, clocking is started from the time when the video signal detecting means detects the absence of the video signal, and the video signal is detected. And a power supply circuit control means for controlling the power supply circuit so as to turn off the power circuit and the heater after a time period preset in the timer means has elapsed.

According to the second aspect described above, even if the application software intentionally displays a black image for a relatively short time period, it is possible to prevent the power circuit and the heater from being accidentally turned off. However, it is possible to reduce unnecessary consumption of electric power and prolong the life of the CRT.

In any of the first and second aspects described above, the CRT display device detects the absence of the synchronization signal of the main device and turns on the power circuit and the heater after a lapse of a predetermined time period. It is preferable to further include means for controlling the power supply circuit to turn off. According to this, even when the power of the main device such as the host computer is turned off, the power circuit and the heater can be turned off.

In any of the above-mentioned first and second aspects, the video signal detecting means does not detect all the video signals of red, green and blue, but either red or blue. You may make it detect only the video signal of the color. As described above, the red or blue video signal is selected as the detection target, not the green video signal, because the green video signal is a composite video signal in which the synchronization signal is superimposed on the green video signal from the main device to the CRT display. It may be sent to the device, and in that case, if the green video signal is to be detected, it is necessary to remove the synchronization signal from the composite video signal, which complicates the circuit. Further, if only the red or blue video signal is to be detected, the structure of the video signal detecting means can be simplified. Nevertheless, the video signal detection means need only detect either the red or the blue video signal to detect the absence of the video signal. Note that both the red video signal and the blue video signal may be detected.

The present invention also provides a CRT as described above.
The present invention is also directed to a power control method for a display device.

In this power supply control method, in response to the absence of the video signal, a step of controlling the main power supply so as to turn off the power circuit, and a predetermined time period has elapsed in the off state of the power circuit. And then controlling the auxiliary power source to turn off the heater.

Further, in the power supply control method according to the present invention, the main power supply is controlled so as to turn off the power circuit after a lapse of a predetermined time period from the start of the state without the video signal, and The auxiliary power supply may be controlled so as to turn off the heater.

[0021]

1 is a block diagram showing the electrical construction of a CRT display device according to an embodiment of the present invention. This CRT display device is connected to a main device that generates a synchronizing signal and a video signal, such as a host computer, and displays an image of the video signal.

This CRT display device comprises a power supply circuit 3 connected to a commercial AC power supply 1 via a main power supply switch 2. The power supply circuit 3 includes a main power supply 4 and an auxiliary power supply 5.

The CRT display device further includes a power circuit 9 including a high voltage circuit 6, a deflection circuit 7 and a video circuit 8, and the high voltage circuit 6, the deflection circuit 7 and the video circuit 8 are driven by a main power supply 4. To be done.

The CRT 10 includes an anode 11 to which a high voltage DC voltage is applied from the high voltage circuit 6, a deflection yoke 12 to which a deflection current is applied from the deflection circuit 7, a cathode 13 to which a cathode drive signal is applied from the video circuit 8, and an auxiliary power supply 5. The heater 14 is provided with an electric current from the heater.

The CRT display device also includes a CPU
15, a synchronization processing circuit 16 and a video input processing circuit 17 are provided. The CPU 15, the synchronization processing circuit 16, and the video input processing circuit 17 are driven by the auxiliary power supply 5.

A sync signal from a host computer (not shown) is processed through a sync signal input terminal 18 and, if it is a composite video signal on which the sync signal is superimposed, a sync signal is processed through a video signal input terminal 19. It is provided to the circuit 16. The synchronization processing circuit 16 performs processing such as waveform shaping of the synchronization signal, polarity determination, synchronization separation, and automatic switching of composite video signals. The desired synchronization signal thus processed is applied to the high-voltage circuit 6 and the deflection circuit. CP given to circuit 7
Given to U15.

The video signal from the host computer is given to the video input processing circuit 17 via the video signal input terminal 19. The video input processing circuit 17 performs processing such as amplification of the video signal, and the video signal thus processed is given to the video circuit 8. The video input processing circuit 17 also includes a video signal detecting means for detecting the presence or absence of a video signal from the host computer. Details of the video signal detecting means are shown in FIG.

As shown in FIG. 2, the video signal detection circuit 20
Is designed to detect the presence of a blue video signal,
The analog signal as the blue video signal is supplied to the voltage amplifier 21.
Is input to and amplified here. The output of the voltage amplifier 21 is given to the base of the transistor 22. When the voltage applied to the base becomes equal to or lower than a predetermined value, the transistor 22 is switched and the predetermined voltage is input to the monostable multivibrator 23. In the monostable multivibrator 23, the pulse width of the vertical scanning period is 3 or more.
A signal having a pulse width of 8 milliseconds is output as a video signal detection signal, and this video signal detection signal is given to the CPU 15.

Referring again to FIG. 1, when the video signal detection circuit 20 detects the presence / absence of the blue video signal, the CPU 15 determines the power circuit as will be made clear by the description of the power supply control procedure described later. 9, a main power supply control means for controlling the main power supply 4 so as to turn on / off 9, a first timer means for timing the off state of the power circuit 9, and a lapse of a time period preset in the first timer means. And an auxiliary power supply control means for controlling the auxiliary power supply 5 so as to turn off the heater 14 later. Further, the main power supply control means described above includes a second timer means for measuring a state where there is no video signal, and a power circuit off means for turning off the power circuit 9 after a time period preset in the second timer means has elapsed. And a blanking signal generating means for applying a video blanking signal to the video circuit 8 for a predetermined time period when the video signal detection circuit 20 detects the presence of the video signal. Further, the CPU 15 further includes means for detecting the absence of the synchronization signal of the host computer and controlling the power supply circuit 3 so as to turn off the power circuit 9 and the heater 14 after the elapse of a predetermined time period.

Further, in connection with the CPU 15, forced on / off /
Off switch 24, power save on / off switch 2
5 and a time setting switch 26 are provided. The forced on / off switch 24 gives the CPU 15 a signal for controlling the power supply circuit 3 so as to forcibly turn on / off the power circuit 9 and the heater 14 regardless of the power control state of the CPU 15. . The power save on / off switch 25 switches whether the power circuit 9 and the heater 14 are turned off according to a predetermined procedure when the above-mentioned "screen saver" is activated, that is, whether or not to enter a so-called "power save mode". A signal for this is given to the CPU 15. The time setting switch 26 is operated when changing the time set in the above-mentioned first timer means. In this embodiment, the first timer means restarts the time counting from the time when the video signal detection circuit 20 detects that there is no video signal. The first timer means has 6
A time period of 3 minutes is set, and this time period can be changed in the range of 8 to 63 minutes by operating the time setting switch 26. The second timer means described above is preset with a time period of 3 minutes, but this time period is fixed. Of course, the time period set in the second timer means may be variable.

FIG. 3 is a flow chart showing a power supply control procedure by the CPU 15. FIG. 4 is a diagram showing transitions of some typical states realized in the power save mode obtained according to the power control procedure shown in FIG. 3 in relation to power consumption.

Mainly referring to FIG. 3, step 101
At, the main power switch 2 (FIG. 1) is turned on to start the procedure shown in FIG. When the main power switch 2 is turned on in this way, as shown in FIG. 1, first, the auxiliary power supply 5 is activated, which causes the CPU 1 to operate.
5, the synchronous processing circuit 16 and the video input processing circuit 17 are driven.

Next, at step 102, the set time is set to 63 minutes in the above-mentioned first timer means (shown as "timer F" in FIG. 3), and the above-mentioned second timer means (see FIG. 3 is shown as "timer S".) Is initialized such that the set time is set to 3 minutes. Further, the first and second timer means start timing at the same time as such setting.

Next, at step 103, it is judged whether or not there is a request for turning on by the forced on / off switch 24 (FIG. 1). Here, if there is an ON request, steps 117, 118, 119 and 12 are performed.
0, and out of these steps, step 119
At, the CPU 15 outputs the main power supply control signal, the main power supply 4 is controlled so that the power circuit 9 is turned on, and the heater control signal is output.
The auxiliary power supply 5 is controlled so that the heater 14 is turned on. As a result, the display is performed on the CRT 10.

On the other hand, if there is no on request, the process proceeds to step 104, where the forced on / off switch 2
It is determined by 4 whether or not there is a request for turning off. If there is an off request, the process is led to step 108 so that the power circuit 9 and the heater 14 are turned off.
The main power source 4 and the auxiliary power source 5 are controlled.

If there is no forced off request, step 105
Then, it is determined here whether the sync signal is given from the host computer through the sync signal input terminal 18. If there is no sync signal, step 10
At 7, it is determined whether or not the state without the sync signal continues for 3 seconds or more. If the state without the synchronization signal continues for 3 seconds or more, in step 108, the power circuit 9 and the heater 14 are turned off. In this way, the state where the synchronization signal is interrupted for 3 seconds or more corresponds to the state where the power of the host computer is turned off or the state where the host computer and the CRT display device are not connected. On the other hand, in step 107, when the state without the synchronization signal continues for less than 3 seconds, the power circuit 9 and the heater 14 are not turned off, and the process returns to step 103. As described above, when the power circuit 9 and the heater 14 are turned off, the reason why the host computer waits for 3 seconds in the absence of a synchronization signal is because the mode switching that can occur in the host computer is taken into consideration. This is to prevent the power circuit 9 and the heater 14 from being turned off due to the interruption.

When the sync signal is detected in the above-mentioned step 105, the process proceeds to step 106. In step 106, it is determined by the power save on / off switch 25 shown in FIG. 1 whether the power save mode is set. If the power save mode is switched to the power save mode by the power save on / off switch 25, the power save mode is entered in step 109.

When the power save mode is entered, step 1
At 10, it is determined whether or not it is necessary to change the set time of the first timer means (timer F), that is, the time period from when the power circuit 9 is turned off to when the heater 14 is turned off. That is, the set time of the timer F can be changed within a range of 8 to 63 minutes (5 to 60 minutes after the power circuit 9 is turned off) after the video signal disappears. It is preset to 63 minutes. When it is desired to set a shorter time period from the 63 minutes, for example, a key input is made by the operator. Therefore, in other words, in step 110, it is determined whether or not there is such a key input. When it is necessary to change the set time of the timer F, at step 111, the time setting switch 26 shown in FIG. 1 is operated to change the set time. Simultaneously with the change of the set time, the timer F restarts counting.

When it is not necessary to change the set time in step 110, or when the change of the set time is completed in step 111, the process proceeds to step 112. In step 112, the video signal input terminal 19 shown in FIG.
A video signal is sent from the host computer to the video signal and the video signal detection circuit 20 (FIG. 2) included in the video input processing circuit 17 determines whether or not a blue video signal is detected. When the video signal is detected, the process proceeds to step 117 described above. On the other hand, if the video signal is not detected, the process proceeds to step 113.

In step 113, it is judged whether the state in which the video signal is interrupted continues for 3 minutes or more, which is the set time of the second timer means (timer S). in this way,
If the video signal is interrupted for 3 minutes or more, step 114
At, the power circuit 9 is turned off. On the other hand, if the video signal is interrupted for less than 3 minutes, the process returns to step 103. As described above, when the power circuit 9 is turned off, waiting for 3 minutes in the absence of a video signal is necessary when the application software intentionally gives a uniform black image display for a predetermined period. This is because 9 is not turned off.

Next, at step 115, it is judged whether or not the set time of the timer F has continued for more than the set time of the video signal. If there is no video signal for more than this set time, the heater 1
4 is turned off. As described above, the predetermined time period is provided after the power circuit 9 is turned off and before the heater 14 is turned off. When the video signal is detected again during this time (step 112), This is so that the image display can be quickly returned without waiting for the heating time of the heater 14.

At step 117, the first timer means (timer F) and the second timer means (timer S) are restarted. This restart is performed when there is a forced on request in step 103, when the power save mode is not set in step 106, or when a video signal is detected in step 112.

In step 117, timers F and S
Is restarted, it is determined in step 118 whether the power circuit 9 or the heater 14 has been turned off. If this CRT display device is already used and the power circuit 9 and the heater 14 are turned on,
Return to step 103. On the other hand, when the use of this CRT display device is started, when the power circuit 9 is turned off in step 114, or when the heater 14 is turned off following the power circuit 9 in step 116, the process proceeds to step 119. The power circuit 9 and the heater 14 are turned on here. As a result, image display is started on the CRT 10.

When image display is started in step 119, a video blanking signal is applied to the video circuit 8 for 2 seconds in step 120. This is because when the power circuit 9 is off, but the heater 14 is on, the video signal is detected in step 112, and when the power circuit 9 is turned on in step 119, a distorted image is displayed on the CRT 10. This is to prevent such disturbed images from being shown. That is, when the high-voltage circuit 6, the deflection circuit 7, and the video circuit 8 are all turned on, the high-voltage circuit 6 and the deflection circuit 7 become unstable at the time of rising, and the video signal is input to the video circuit 8 at this stage. If done, CRT
The distorted image is displayed at 10. Therefore, when the video blanking signal is given to the video circuit 8 for a period of, for example, 2 seconds until the high voltage circuit 6 and the deflection circuit 7 become stable, a uniform black image is displayed on the CRT 10 and a disturbed image is displayed. It can be prevented from displaying. After the lapse of 2 seconds, the video signal is input to the video circuit 8 and the CRT 1
At 0, normal image display is performed.

The above-described power control procedure will be described in connection with the typical state transition in the power save mode shown in FIG.

In the state A shown in FIG. 4, normal image display is performed on the CRT 10. In this state, when the power save mode is set, steps 103, 104, 105, 106, 109, 11
0, 112, 117 and 118 to step 10
According to the loop returning to 3, the procedure shown in FIG. 3 is executed. On the other hand, when the power save mode is not used, steps 103, 104, 105, 106, 117
The procedure shown in FIG. 3 is executed according to the loop returning to step 103 through steps 118 and 118.

In the above-mentioned state A, when the video signal from the host computer is interrupted while using the power save mode, the state changes to state B in FIG. As described above, when the “screen saver” is operating and the same display is made on the CRT 10 for a certain period, the CRT 10 displays a uniform black image in order to prevent the phosphor attached to the CRT 10 from being burned. To do so, the video signal from the host computer is cut off. Thus, in response to the disconnection of the video signal, the state A
To state B. In this state B, steps 103, 104, 105, 106, 109, 11
The procedure shown in FIG. 3 is executed according to a loop returning from 0, 112 (or 111, 112) and 113 to step 103.

In the above-mentioned state B, when the time period of 3 minutes has elapsed, the power circuit 9 is turned off, and as a result, the state C shown in FIG. 4 is entered. In state C, steps 103, 104, 105, 106, 109, 11
The procedure shown in FIG. 3 is executed in a loop following steps 0, 112, 113, 114 and 115 and returning to step 103.

In the above-mentioned state C, a predetermined time period set in the first timer means (timer F) after the video signal is cut off, that is, 8 to 63 minutes (5 to 5 after transition from state B to C) After 60 minutes), the heater 14 is turned off, and as a result, the state D is entered. In this state D, steps 103, 104, 105, 106, 10
9, 110, 112, 113, 114, 115 and 1
The procedure shown in FIG. 3 is executed according to the loop returning from step 16 to step 103.

In any of the above-mentioned states B, C and D, the step 112 is passed, but in these states, when the video signal from the host computer is given again, the step 112 is followed by the step 117. Get burned. After that, when in the state B, both the electric power circuit 9 and the heater 14 are turned on, so in step 118 following step 117, the process goes to “N”, returns to step 103, and the normal image is displayed on the CRT 10. The display returns to the display state, that is, the state A.
On the other hand, if the state is C or D, step 11
In step 118 following step 7, the process goes to "Y", and the process returns to step 103 through steps 119 and 120.
As a result, the CRT 10 returns to the state in which normal image display is performed, that is, the state A.

Regarding the above-mentioned return to the state A, when it is performed from the state B, the return is made instantly. When returning from the state C to the state A, the video blanking signal given for 2 seconds in step 120 causes the return after 2 seconds. Also, from state D to state A
In the case of returning to (1), it is necessary to increase the temperature of the heater 14, so that an experimentally returning time of 10 to 15 seconds is necessary.

FIG. 4 shows an example of the power consumed by the CRT display in each of the states A, B, C and D. 100 power consumed in state A
%, 86% in state B and 11 in state C
%, In state D, 5.7% of power is consumed. Note that these specific percentages are merely examples. Because the power consumption in state A is
This is because it varies depending on the content of image display on the CRT 10 and also varies depending on the size of the CRT 10.

Although the present invention has been described above with reference to the preferred embodiment, in the power supply control method according to the present invention,
It is also possible to change as follows.

That is, in the transition of each state shown in FIG. 4, the state B may be omitted and the power supply control may be performed so as to transit from the state A to the state C and the state D. In this case, step 113 shown in FIG. 3 is omitted.

In FIG. 4, the state C is omitted and
Power control may be performed so as to transit to the state D after passing through the states A and B. In this case, steps 110, 111 and 115 in FIG. 3 are omitted.

Further, in the power supply control procedure shown in FIG. 3 described above, the timing of the OFF control of the heater 14 in step 116 is obtained, so in step 115, the first timer means (timer F) loses the video signal. It was supposed to start timing from the time. However, instead of this, in order to obtain the timing for controlling the heater 15 to be turned off, a timer unit configured to start time counting from the time when the power circuit 9 is turned off may be used. Such a control procedure will be described with reference to FIG.

FIG. 5 is a flow chart showing a power supply control procedure executed in another embodiment of the present invention. In FIG. 5, steps corresponding to the steps shown in FIG.
The same reference numerals are given, and duplicate explanations are omitted.

In the control procedure shown in FIG. 5, one timer is used, and this timer gives both the timing for controlling the power circuit 9 to turn off and the timing for controlling the heater 14 to turn off. That is, this timer has
First, a set time of 3 minutes for controlling the power circuit 9 to be turned off is set, and clocking is started. After completing the time measurement for 3 minutes, the same timer is set for 5 to 60 minutes and the time measurement is started. In step 102a shown in FIG. 5, a set time of 3 minutes is set in such a timer, and at the same time as this setting, time counting is started. Further, the set time of 60 minutes to be set next in the timer is stored in the CPU 15.

When it is determined in step 110 shown in FIG. 5 that the time period from when the power circuit 9 is turned off to when the heater 14 is turned off needs to be changed, this time is determined in step 111a. The period is changed in the range of 5 to 60 minutes, and the changed time period is set to the CPU1.
Stored in 5.

When no video signal is detected in step 112, the process proceeds to step 200. In step 200, it is determined whether the power circuit 9 is turned off. If the power circuit 9 is not turned off, it is determined in step 113 whether or not the video signal has been interrupted for 3 minutes or more. When the video signal has been cut off for more than 3 minutes, the power circuit 9 is turned off in step 114.

Next, at step 210, the timer is set with the data concerning the time period of 5 to 60 minutes stored in the CPU 15 and the time counting of the timer is started. Next, in step 115a, it is determined whether or not a set time of 5 to 60 minutes has elapsed since the power circuit 9 was turned off. When the power circuit 9 remains off for more than this set time, the heater 14 is turned off in step 116 as in the above-described embodiment.

In step 200, if the power circuit 9 is turned off, the step 115 is directly executed.
is led to a. Also, steps 113 and 115a
In each of the above cases, if the time period currently measured by the timer has not elapsed, the process returns to step 103.

When a video signal is detected in step 112, the process proceeds to step 117a. In step 117a, the timer is set to 3 minutes and the time measurement is restarted according to the set time of 3 minutes.

The other control procedure shown in FIG. 5 is substantially the same as that shown in FIG.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration provided in a CRT display device according to an embodiment of the present invention.

2 is a block diagram showing a video signal detection circuit 20 included in the video input processing circuit 17 shown in FIG.

3 is a flowchart showing a power supply control procedure executed by a CPU 15 shown in FIG.

FIG. 4 is a diagram showing transitions of some typical states realized in the power save mode obtained according to the power control procedure shown in FIG. 3, in relation to power consumption.

FIG. 5 is a flowchart corresponding to FIG. 3, showing a power supply control procedure executed in another embodiment of the present invention.

[Explanation of symbols] 3 power supply circuit 4 main power supply 5 auxiliary power supply 6 high voltage circuit 7 deflection circuit 8 video circuit 9 power circuit 10 CRT 11 anode 12 deflection yoke 13 cathode 14 heater 15 CPU 16 synchronization processing circuit 17 video input processing circuit 18 synchronization Signal input terminal 19 Video signal input terminal 20 Video signal detection circuit 24 Forced on / off switch 25 Power save on / off switch 26 Time setting switch

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical display location G06F 1/26 (72) Inventor Toshihisa Tanabe 153 Shimo-Kashiwano-cho, Matsuto-shi, Ishikawa Nanao

Claims (11)

[Claims] 1. A CR, which is connected to a main device for generating a synchronizing signal and a video signal to display an image of the video signal.
A T display device, a power supply circuit including a main power supply and an auxiliary power supply, a power circuit driven by the main power supply, including a high-voltage circuit, a deflection circuit, and a video circuit, and a synchronization signal from the main device. A processing unit for processing and processing the video signal, including a synchronization processing circuit for applying the processed and processed synchronization signal to the high-voltage circuit and the deflection circuit, and a video signal detection unit for detecting the presence or absence of the video signal from the main device. A video input processing circuit for applying the generated video signal to the video circuit, and an anode to which a high voltage DC voltage is applied from the high voltage circuit,
A CRT that includes a deflection yoke to which a deflection current is applied from the deflection circuit, a cathode to which a cathode drive signal is applied from the video circuit, and a heater to which a current is applied from the auxiliary power source; A main power supply control means for controlling the main power supply so as to turn on / off the power circuit when presence / absence is detected; and a first timer means for measuring at least a time period during which the power circuit is off. A CRT display device comprising: an auxiliary power supply control unit that controls the auxiliary power supply to turn off the heater after a preset time period has elapsed in the first timer unit. 2. The CRT display device according to claim 1, wherein the main power supply control means is preset in the second timer means for measuring a state in which there is no video signal and the second timer means. Power circuit off means for turning off the power circuit after the elapse of the predetermined time period. 3. The CRT display device according to claim 1, wherein the time period preset in the first timer means is variable. 4. The CRT display device according to claim 1, wherein the main power supply control means, when the video signal detection means detects the presence of the video signal, displays an image on the video circuit. A blanking signal generating means is provided for giving a ranking signal for a predetermined time period. 5. A CR, which is connected to a main device for generating a synchronizing signal and a video signal to display an image of the video signal.
A T display device, a power supply circuit including a main power supply and an auxiliary power supply, a power circuit driven by the main power supply, including a high-voltage circuit, a deflection circuit, and a video circuit, and a synchronization signal from the main device. A processing unit for processing and processing the video signal, including a synchronization processing circuit for applying the processed and processed synchronization signal to the high-voltage circuit and the deflection circuit, and a video signal detection unit for detecting the presence or absence of the video signal from the main device. A video input processing circuit for applying the generated video signal to the video circuit, and an anode to which a high voltage DC voltage is applied from the high voltage circuit,
A CRT that includes a deflection yoke to which a deflection current is applied from the deflection circuit, a cathode to which a cathode drive signal is applied from the video circuit, and a heater to which a current is applied from the auxiliary power source; Timing is started from the time when it is detected that the video signal is not present, and timer means for timing the absence of the video signal, and the power circuit and the heater are turned off after a lapse of a preset time period in the timer means. And a power supply circuit control means for controlling the power supply circuit.
Display device. 6. The CRT display device according to claim 1, 2 or 5, wherein the power circuit and the heater are turned off after a lapse of a predetermined time period after detecting that there is no synchronization signal of the main device. Further comprising means for controlling the power supply circuit. 7. The CRT display device according to claim 1, 2 or 5, wherein the video signal includes video signals of respective colors of red, green and blue, and the video signal detecting means includes the red or The presence or absence of a blue video signal is detected. 8. A CRT display device, which is connected to a main device for generating a video signal and displays an image of the video signal, comprising a CRT including an anode, a deflection yoke, a cathode and a heater, and a high voltage direct current to the anode. A power circuit including a high-voltage circuit for applying a voltage, a deflection circuit for applying a deflection current to the deflection yoke, and a video circuit for applying a cathode drive signal to the cathode, a main power source for supplying a power source for driving the power circuit, and a current for the heater. A power supply control method for a CRT display device, comprising: a power supply circuit including an auxiliary power supply for providing the power supply, controlling the main power supply to turn off the power supply circuit in response to the absence of the video signal, The auxiliary power supply is controlled so as to turn off the heater after a predetermined time period has passed while the circuit is off. Power supply control method for a CRT display device comprising a step. 9. The power supply control method according to claim 8, wherein the step of controlling the main power supply to turn off the power circuit is performed until a predetermined time period elapses in the absence of the video signal. Maintaining the power circuit on; and turning off the power circuit after the elapse of the predetermined time period. 10. The power supply control method according to claim 8, wherein a time period from turning off the power circuit to turning off the heater is variable. 11. A CRT display device connected to a main device for generating a video signal to display an image of the video signal, the CRT including an anode, a deflection yoke, a cathode and a heater, and a high voltage direct current to the anode. A power circuit including a high-voltage circuit for applying a voltage, a deflection circuit for applying a deflection current to the deflection yoke, and a video circuit for applying a cathode drive signal to the cathode, a main power source for supplying a power source for driving the power circuit, and a current for the heater. A power supply control method for a CRT display device, comprising: a power supply circuit including an auxiliary power supply for providing a power supply circuit, wherein the power supply circuit is turned off after a lapse of a predetermined time period from the start of the state without the video signal. Controlling the main power supply and controlling the auxiliary power supply to turn off the heater Provided, CRT
A power control method for a display device.