JP2000089860A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device capable of surely detecting the presence/ absence of an operator. SOLUTION: Screen erasing permission by the presence/absence of signals from an infrared ray sensor 1 is performed by opening the switch SW of a CRT control part 3. In this case, the control circuit 31 of the CRT control part 3 detects RGB signals from the logic circuit 71 of a central processing part 7 and inputs the signals to the AND circuit 33 of the CRT control part 3. When the infrared ray sensor 1 detects heat, it is sensed by the detection circuit 21 of a sensor detection part 2 and converted into a electric signals. A PCP 22 is operated after a fixed time corresponding to a time constant constituted by a resistor R1 and a capacitor C1, and input is performed to the AND circuit 33 of the CRT control part 3. When the AND condition of the AND circuit 33 is established, a voltage is applied through a diode D1 to the base of the transistor TR of a CRT power source control circuit 32, the voltage from the stabilization circuit 63 of a power source part 6 is supplied to a CRT display circuit part and a CRT performs display.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly to a display device aiming at low power consumption.

[0002]

2. Description of the Related Art A supervisory control system (a system generally including a building management system in a broad sense) is divided into a supervisory control system and a monitored control system. The supervisory control system is a central processing unit (CPU). ), Display (CRT; cathode ray tube; cathode ray tube, liquid crystal, other flat displays, etc.)
It is composed of a device, a file server, a message printer, a logging printer, a color hard copy device, and the like.
The monitored control system includes an interface unit with the monitored and controlled equipment, a memory unit for storing data, and a transmission unit that sends data to the monitoring control system. (Local area network).

A monitored control system (apparatus) monitors the status of each facility device (monitoring target device) and transmits the monitoring information to the monitoring control system. The data sent to the monitoring and control system is stored in the file server, processed by the central processing unit, and displayed on the CRT unit (device). Also, CR
By performing control on the corresponding device from the T unit, a signal is transmitted from the monitored control device to control the corresponding device.

In such a monitoring and control system,
For example, when an operator (operator; operator) is absent in front of the display device, especially when the display is a CRT, the screen display is erased for the purpose of saving energy or preventing screen burn-in ( Broad screen saver function) is desirable. 4-10
No. 4331, in a control panel equipped with a display, an ultrasonic sensor for detecting an operator is attached to a display on the control panel, and when the sensor does not detect an operator, a display circuit is controlled to display a display on the display. A method of erasing has been proposed.

[0005]

Problems to be Solved by the Invention
In the control panel equipped with the display described in Japanese Patent Application Publication No. 1 (1994), a person in front of the display is detected by an ultrasonic sensor, and CRT display control is performed assuming that an operator is present. However, since the transmitted ultrasonic wave is reflected by the obstacle and received and detected by the ultrasonic sensor, even if a person (operator) does not exist, irregular reflection and other similar CRTs may be used. A malfunction may occur due to a disturbance, and as a result, there is a problem that the CRT keeps displaying even when not in use.

An object of the present invention is to provide a display device capable of reliably detecting the presence of an operator.

[0007]

According to the present invention, there is provided a display apparatus comprising: an operator detecting means for thermally detecting the presence or absence of an operator; and power supply to a display unit only when the presence of the operator is detected. And a power supply control means. The operator detecting means is an infrared sensor. Further, the operator detecting means detects the presence or absence of a heat source on the front surface of the display unit. Still further, a screen saver function is provided for stopping the display on the display unit when an input from a keyboard or a mouse is absent for a predetermined time or more.

The operation of the present invention is as follows. Since the presence or absence of an operator is thermally detected by using an infrared sensor, by appropriately adjusting the sensitivity, it is possible to detect only a person near the display device (CRT), and the ultrasonic Malfunction due to irregular reflection from the sensor or other similar disturbance from the CRT can be prevented. In order to reduce malfunctions due to disturbances, the time constant is set to a large value within a range that does not cause the operator to feel uncomfortable.

Further, in addition to the infrared sensor, a screen erase switch is provided on a keyboard connected to the central processing unit.
The screen saver function is also possible from this switch. Furthermore, even when a person is working in front of the CRT, if the keyboard or mouse is not used for a predetermined time, the screen saver function can minimize the deterioration of the display.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an embodiment of a display device according to the present invention. FIG.
The display device according to the present invention includes a CRT unit 10 having a display function, a central processing unit (computer; CPU) 7 for controlling the entire device, a keyboard 8 for inputting to the central processing unit 7, and a mouse 9.

The central processing unit 7 receives signals from the keyboard 8 connected thereto, controls RGB signals (three primary color signals; signals to be displayed on the CRT 5), and
It has a screen saver function, and the screen saver function can be canceled by the keyboard 8 and the mouse 9. Here, the screen saver function is a function for stopping the display output of the RGB signal and not displaying the CRT 5 when there is no input from the keyboard 8 or the mouse 9 continuously for a fixed time or more.

The CRT unit 10 includes an infrared sensor 1 for detecting heat, a sensor detection unit 2 for detecting an output signal from the infrared sensor 1, a signal from the sensor detection unit 2, and an RGB signal from the central processing unit 7. And a CRT control unit 3 for detecting the presence or absence of the CRT and controlling the voltage (power supply) supplied to the CRT display circuit unit 4. Further, a voltage is supplied from the CRT control unit 3 to display a CRT 5, a CRT display circuit unit 4, a display screen (including a CRT, a liquid crystal display, etc.) 5 displaying an output signal of the CRT display circuit unit 4, and a CRT unit. It has a power supply section 6 for supplying power to the power supply 10.

The operation of the embodiment of the present invention will be described with reference to the detailed block diagram of FIG. 2 and the timing charts of FIGS. Screen erasure permission based on the presence or absence of a signal from the infrared sensor 1 can be performed by opening the switch SW of the CRT control unit 3. In this case, the control circuit 31 of the CRT control unit 3
Detects the RGB signal from the logic circuit 71 of the central processing unit 7 and inputs the output to the AND circuit 33 of the CRT control unit 3.

On the other hand, when the infrared sensor 1 detects heat, it is detected by the detection circuit 21 of the sensor detection unit 2, converted into an electric signal, and fixed for a time corresponding to a time constant constituted by the resistor R1 and the capacitor C1. The post-photocoupler (PCP) 22 operates, and a positive potential (logical value “1”) is input from the + power source via the resistors R3 and R2 to the AND circuit 33 of the CRT control unit 3. Note that the photocoupler 22 is an element that includes a light emitting diode and a light activated transistor, and that transmits a signal in a form in which a DC potential is isolated.

When the AND condition of the AND circuit 33 is satisfied, a positive voltage is applied to the base of the power control (NPN) transistor Tr of the CRT power control circuit 32 via the diode D1. Voltage is CR
This is supplied to the T display circuit section 4, and the CRT 5 performs display. The power supply unit 6 is connected to a commercial power supply (100 V A
C) is transformed by a power transformer 61 and converted into a direct current through a rectifier 62, and then power is supplied to each unit via a stabilizing circuit 63. The timing chart in this case corresponds to the case where there are the RGB signal and the signal from the infrared sensor 1 shown in FIG.

When the RGB signals from the logic circuit 71 are cut by the assigned keys of the keyboard 8, the AND condition is not satisfied even if the signal from the infrared sensor 1 is detected. Also, when the RGB signal is detected and the signal from the infrared sensor 1 is not detected, the AND condition is not satisfied,
Since no voltage is supplied to the CRT display circuit section 4, the CRT 5
Will not be displayed. These are the RGB shown in FIG.
The timing chart corresponds to the case where there is no signal and there is a detection signal from the infrared sensor 1 and the case where there is an RGB signal shown in FIG. 5 and there is no detection signal from the infrared sensor 1.

Regardless of the presence or absence of a signal from the infrared sensor 1, the screen erasure prohibition can be performed by closing the switch SW of the CRT control unit 3. In this case, regardless of the presence or absence of a detection signal from the infrared sensor 1, a positive voltage is applied to the base of the power supply control (NPN) transistor Tr of the CRT power supply control circuit 32 via the resistor R3. The voltage from the section 6 is supplied to the CRT display circuit section 4. Accordingly, the CRT 5 is displayed unless the RGB signals are cut by the keys of the keyboard 8 or by the screen saver function.

Further, as can be seen from the timing charts shown in FIGS.
Under the condition of ON, as long as the RGB signal is not cut, regardless of the presence or absence of the output of the infrared sensor detection unit, the CRT
Since power is supplied to the display circuit, the CRT performs display.

[0019]

As described above, the present invention has an effect that the added infrared sensor detects the operator in front of the CRT and automatically displays the CRT in order to save energy and prevent deterioration of the CRT. In addition, there is an effect that when the operator has left the CRT, it is automatically deleted. In addition, when the input from the keyboard or mouse has not been continued for a certain period of time, the screen saver function
There is an effect that the T screen can be erased.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a detailed block diagram of an embodiment of the present invention.

FIG. 3 is a timing chart of the embodiment of the present invention.

FIG. 4 is a timing chart of the embodiment of the present invention.

FIG. 5 is a timing chart of the embodiment of the present invention.

FIG. 6 is a timing chart of the embodiment of the present invention.

FIG. 7 is a timing chart of the embodiment of the present invention.

FIG. 8 is a timing chart of the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Infrared sensor 2 Sensor detection part 3 CRT control part 4 CRT display circuit part 5 CRT 6 Power supply part 7 Central processing part 8 Keyboard 9 Mouse 10 CRT part

Claims (5)

[Claims] An operator detecting means for thermally detecting the presence or absence of an operator, and a power control means for supplying power to a display unit only when the presence of the operator is detected. Display device. 2. The display device according to claim 1, wherein said operator detecting means is an infrared sensor. 3. The display device according to claim 1, wherein the display unit is configured by a cathode ray tube. 4. The display device according to claim 1, wherein said operator detecting means detects the presence or absence of a heat source on a front surface of said display unit. 5. The display device according to claim 1, further comprising a screen saver function for stopping display on said display unit when an input from a keyboard or a mouse has been absent for a predetermined time or more.