JP2002328669A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a displayed screen not disappear in a display device having a power saving mode, even if a user leaves his seat for a while. SOLUTION: The display device is provided with a detection element 33 for detecting existence of a user USR, and time circuits 31 and 34 for indicating times TA and TB (TB>TA) after the user USR becomes non-existent from the detection output of the detection element 33. The display device is provided with a formation circuit 35 for forming an alarm signal S35, and a control circuit 31 for controlling a power source circuit 36 and the formation circuit 35 according to the output of the time circuits 31 and 34. When the time after the user USR becomes absent does not reach the time TA, the device is set to the normal operation mode. When the time after the user USR becomes absent reaches the time TA, the alarm signal S35 is formed, the alarm signal S35 is supplied to the display device 23, and the warning pattern is displayed. When the time after the user USR becomes absent reaches the time TB, the operating voltage to be supplied to the display device 23 is interrupted by controlling the power source circuit 36.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a display device.

[0002]

2. Description of the Related Art As a display device used in combination with a personal computer or the like, a device that detects when a user leaves a seat and shifts from a normal mode to a power saving mode has been put into practical use. I have. In this power saving mode, the screen of the display device disappears, so that not only power saving can be realized, but also it is preferable for the backlight of a CRT or LCD used as a display device.

[0003]

By the way, as described above, when the user leaves the seat, this can be detected, for example, as shown in FIG. That is, the infrared LED 51 is provided on the front of the display device 50.
And an infrared phototransistor 52 are provided.
The infrared ray IR is emitted from the ED 51 toward the user USR, and the reflected light is received by the phototransistor 52. Then, when the level of the signal output from the phototransistor 52 becomes lower than the specified value, it is determined that the user USR has disappeared from the front of the display device 50.

However, in the case of such a method, even if the user USR leaves the seat for a while, for example, to take reference data, the system shifts to the power saving mode. The screen disappears abruptly, which may confuse the user USR.

[0005] The present invention is to solve such a problem.

[0006]

The present invention has the following configuration. That is, for example, a display device that is supplied with a video signal and displays an image having contents corresponding to the video signal, a power supply circuit that supplies an operating voltage to the display device, a detection element that detects the presence of a user, A time circuit indicating a first time TA and a second time TB (TB> TA) after the absence of the user from the detection output of the detection element, and a warning signal displayed as a warning pattern on the display device. A forming circuit to be formed, and a control circuit for controlling the power supply circuit and the forming circuit according to the output of the time circuit, wherein the output of the time circuit is the first time after the absence of the user. When it is indicated that TA has not been reached, the normal operation mode is set, and the output of the time circuit becomes the absence of the user. The first
When the time TA has been reached, the control circuit controls the formation circuit to form the warning signal, and supplies the warning signal to the display device to display the warning pattern on the display device. When the display on the device indicates that the output of the time circuit has reached the second time TB after the absence of the user, the control circuit controls the power supply circuit to control the display. A display device adapted to cut off an operating voltage supplied to a device. Therefore, when the user leaves the seat for a moment, a warning is displayed without shifting to the power saving mode.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 10 denotes a personal computer, and reference numeral 20 denotes an example of a display device according to the present invention. Then, the display device 20
In, a video signal from the personal computer 10 is supplied to a video circuit 22 through a connector 21 and subjected to predetermined processing such as gamma correction, and then supplied to a display device, for example, an LCD panel 23.
An image having contents corresponding to the video signal is displayed.

Further, the display device 20 is provided with a microcomputer 31 as a power saving control circuit. The microcomputer 31 is provided with a power saving routine 100 as shown in FIG. 2, for example, as a part of a program executed by the CPU (not shown). The details of the routine 100 will be described later, but FIG. 2 shows a portion related to the present invention.

Further, as shown in FIG. 4, for example, an infrared LED 32 and an infrared phototransistor 33 are provided as a light emitting element and a light receiving element in the lower part of the front surface of the display device 20. Then, as described later, the infrared light L is output from the port output Q of the microcomputer 31.
The light emission of the ED 32 is controlled, and when the light emission is permitted, the infrared LED 32 irradiates the infrared rays IR to the user USR at the correct position.

Then, the infrared rays I reflected by the user USR
R is received by the phototransistor 33, and the output signal of the phototransistor 33 is supplied to the detection circuit 34, and the user USR is moved from the display device 20 to a predetermined position (for example, when the personal computer 10 is normally used). 5), for example, 5V, and when leaving the position, a detection voltage V34 that decreases with time is extracted. It should be noted that even when the voltage V34 is lower than 5V, the user US
When R returns to a predetermined position, it immediately rises to 5V.

That is, when the user USR is in front of the display device 20, V34 = 5V.
When the USR leaves the seat, the voltage V34 gradually decreases from that point. However, when user USR returns to his seat, V34
= 5V.

The voltage V34 is supplied to an analog input port (A / D converter circuit) A / D of the microcomputer 31.

A forming circuit 35 for forming, for example, a display signal for an OSD is connected to the microcomputer 31. Then, the forming circuit 35 includes the microcomputer 3
1 to form various display signals, a predetermined warning signal S35 is formed as a part of the display signals,
This warning signal S35 is supplied to the video circuit 22.

Further, the output voltage of the power supply circuit 36 is supplied to each part of the display device 20 as their operating voltage. At least the operating voltage supplied to the video circuit 22 and the LCD panel 23 is controlled by the microcomputer 31 to a predetermined value. State controlled.

In such a configuration, when the user USR is in front of the display device 20, V34 = 5V, but when the user USR leaves, the voltage V34 gradually decreases. When the user USR leaves the front of the display device 20, the elapsed time is indicated.

Therefore, in the present invention, as shown in FIG. 3, voltage values VA and TB (VA> VA) corresponding to elapsed times TA and TB (TA <TB) when user USR leaves display device 20. VB).

If V34 ≧ VA, the user USR:
Since the time TA has not elapsed even if the user is in front of or away from the display device 20, a normal display is performed (normal mode). However, if VA> V34 ≧ VB, the user USR
Is longer than the time TA from the display device 20, so that the LCD panel 2
A warning is displayed at 3 (warning display mode). In addition, V34
If <VB, the user USR has been away from the display device 20 for a time longer than the time TB, so that the video circuit 22 and the LCD panel 23 are turned off (power saving mode). The voltages VA and VB can be arbitrarily set by the user USR.

The power saving routine 100 shown in FIG.
The above operation mode switching is realized. That is, when the power of the display device 20 is turned on, the microcomputer 31 starts the processing of the routine 100 from step 101, and then proceeds to step 102.
In step, the emission of the infrared LED 32 is permitted. Then, in step 103, the voltage V34 is taken into the microcomputer 31.

Next, at step 104, the voltage V34
Is compared with the warning judgment value VA, and when V34 ≧ VA, the process proceeds from step 104 to step 105. Then, in this step 105, it is determined whether or not the current mode is the warning display mode. If not, the process returns from step 105 to step 103.

Therefore, if the user USR is in front of the display device 20 or is within the time TA even if the user USR is separated, an image based on a video signal from the personal computer 10 is displayed on the screen of the LCD panel 23. That is, it is the normal mode. Then, in this normal mode, steps 103, 104 and 105 are repeated.

However, even in the normal mode, if the time that the user USR is away from the front of the display device 20 exceeds the time TA, V34 <VA, and this is detected in step 104. Proceed to step 111. In this step 111, the microcomputer 31 controls the formation circuit 35 to generate a warning signal S35, and this warning signal S35
Is supplied to the video circuit 22.

Therefore, as shown in FIG. 4 (FIG. 4B
Is an enlarged view of the main part of FIG.
, An image based on a video signal from the personal computer 10 is displayed, and a warning pattern 40 based on the warning signal S35 is displayed blinking by superimposition. This is the warning display mode, and therefore has transited from the normal mode to the warning display mode as shown by the arrow in FIG.

Subsequently, the process proceeds to step 112, in which the voltage V34 is set to the absence determination value VB.
And if V34 ≧ VB, the process proceeds to step 1
The process returns to step 103 from step 12. Therefore, VA> V3
When 4 ≧ VB, the warning display mode is set.
Steps 103, 104, 111, and 112 are repeated.

Then, when the time (TB-TA) elapses after entering the warning display mode, ie, when the user
If the USR is away from the display device 20 for more than the time TB, then V34 <VB, which is detected in step 112, and the process proceeds to step 112.
To step 121. And this step 12
1, the microcomputer 31 controls the power supply circuit 36 to control the video circuit 22 and the LCD panel 2.
The supply of the operating voltage to 3 is cut off. This is the power saving mode, and therefore, has transited from the warning display mode to the power saving mode as indicated by the arrow in FIG.

Subsequently, the process proceeds to step 122, where the voltage V34 is set to the warning judgment value VA.
And when V34 <VA, step 122 is repeated. Therefore, when transitioning to the power saving mode, the power saving mode continues until V34 ≧ VA, that is, until the user USR returns to the front of the display device 20.

Then, the user USR enters the display device 2
Returning to before 0, V34≥VA at this time, and this is detected in step 122, and the process proceeds from step 122 to step 123. In this step 123, the power supply circuit 36 is controlled by the microcomputer 31 and the video circuit 22 and the L
The operating voltages are supplied to the CD panel 23, and the formation circuit 35 is controlled to inhibit the generation of the warning signal S35. That is, the normal mode is set.

Accordingly, as shown by the arrow in FIG. 3, the mode has returned from the power saving mode to the normal mode. Then, the process returns to step 103. That is, in the power saving mode, when the user USR returns to the front of the display device 20, the display device 20 returns from the power saving mode to the normal mode.

If the operation mode is the warning display mode in step 105, the process proceeds to step 105.
Then, the process proceeds to step 131, where the formation circuit 35 is controlled to inhibit the generation of the warning signal S35. Therefore, as indicated by the arrow in FIG. 3, the mode has returned from the warning display mode to the normal mode. Then, the process returns to step 103. That is, also in the warning display mode, when the user USR returns to the front of the display device 20, the display device 20 returns from the warning display mode to the normal mode.

As described above, in the above-described display device 20, when the user USR has been away from the display device 20 for a long time, the mode shifts to the power saving mode. The warning pattern 40 is displayed on the display 23, and at this time, the image based on the video signal from the personal computer 10 does not disappear. Therefore, the user USR
However, the display on the LCD panel 23 does not disappear if the user leaves the seat for a while, for example, to obtain reference material, so that the user USR is not confused.

In the above description, the microcomputer 31 can also be used for performing other settings and adjustments. Further, the power saving routine 100 may be executed when the user USR designates from the menu. Further, instead of the detection circuit 34, the software executed by the microcomputer 31 measures the time from the time when the user USR leaves the seat to measure the time TA,
TB can also be determined.

[List of abbreviations used in this specification] A / D: Analog to Digital CPU: Central Processing Unit CRT: Cathode Ray Tube LCD: Liquid Crystal Display LED: Light Emitting Diode OSD: On Screen Demand

[0032]

According to the present invention, when the user leaves the display device for a long time, the display shifts to the power saving mode and the display on the display device disappears.
If the user moves away for a short time, the mode shifts to the warning display mode. At this time, the display on the display device does not disappear, so that the user is not confused.

[Brief description of the drawings]

FIG. 1 is a system diagram illustrating one embodiment of the present invention.

FIG. 2 is a flowchart illustrating one embodiment of the present invention.

FIG. 3 is a diagram for explaining the present invention.

FIG. 4 is a diagram showing an example of a display screen.

FIG. 5 is a diagram for explaining the present invention.

[Explanation of symbols]

10 personal computer, 20 display device, 21 connector, 22 video circuit, 23 LC
D, 31: microcomputer, 32: infrared ray LE
D, 33: infrared phototransistor, 35: forming circuit, 36: power supply circuit, 100: power saving routine

Claims (3)

[Claims] 1. A display device to which a video signal is supplied to display an image corresponding to the video signal, a power supply circuit to supply an operating voltage to the display device, a detection element to detect the presence of a user, A first time TA and a second time TB (TB> TA) after the absence of the user from the detection output of the detection element.
A time circuit indicating a warning signal displayed on the display device as a warning pattern, and a control circuit controlling the power supply circuit and the formation circuit according to an output of the time circuit. When the output of the time circuit indicates that the first time TA has not been reached after the absence of the user, the normal operation mode is set, and the output of the time circuit indicates that the user is absent. When it is indicated that the first time TA has been reached since then, the control circuit controls the formation circuit to generate the warning signal, and supplies the warning signal to the display device. Displaying the warning pattern on the display device; and outputting the output of the time circuit to the second time TB after the absence of the user. When it showed that reached by the control circuit, a display device which controls the power supply circuit so as to cut off the operating voltage supplied to the display device. 2. The display device according to claim 1, wherein the time circuit is configured to form a voltage that gradually decreases from a detection output of the detection element from a time when the user is absent. A comparison circuit for comparing the decreasing voltage with a first voltage and a second voltage lower than the first voltage, wherein the comparison output of the comparison circuit is a voltage gradually decreasing as described above. Indicates that the voltage has reached the first voltage, which is the first time, and indicates that the gradually decreasing voltage of the comparison output of the comparison circuit has reached the second voltage. The display device is configured to set the second time as the second time. 3. The display device according to claim 1, further comprising an infrared LED, wherein the detection element is an infrared detection element, and the infrared light output from the infrared LED and reflected by the user, A display device receiving light by the infrared detection element and obtaining the detection output.