KR200193673Y1 - Device for controlling power of monitor using ultrasonic waves - Google Patents

Abstract

Ultrasonic transmitter 10, reflected wave receiver 20, the reflected wave receiver that uses ultrasonic waves to detect the distance between the monitor and the user in real time to accurately determine the presence of the user and cut off the monitor power in the absence of the user. And a power saving control unit 30 for calculating a distance from the user based on the detected electrical signal and determining the presence or absence of the user according to the calculated distance and instructing the monitor control unit 4 to control the power saving. The distance measurement using ultrasonic wave has less malfunction and high reliability, so it can be used for user's convenience with stable operation. This can reduce power consumption and shorten the lifespan of CRT and LCD which are used as the display means of the monitor. .

Description

DEVICE FOR CONTROLLING POWER OF MONITOR USING ULTRASONIC WAVES}

The present invention can be applied to a computer monitor to prevent unnecessary power consumption, and in particular, relates to a monitor power control device using ultrasonic waves to detect the presence of the user in front of the monitor by using ultrasonic waves to turn off the monitor power in the absence. will be.

With the development of the information industry, the use of personal computers in offices and general households has increased significantly. Especially, the spread of the Internet has led to the fact that computers are always on in general offices, not to mention in offices. A personal computer basically includes a main body, a monitor, and a keyboard, among which a monitor is equipped with a cathod-ray tube (CRT) or a liquid crystal display (LCD) panel, which are main image display means, which consume power in a computer. Is the biggest device. Therefore, the demand for power is increasing according to the increase in the use of computers. The problem is that the monitor is turned on even if the user is away for meetings or outings while using the computer. This increase is shortening the lifespan of CRTs and LCDs. In particular, in a portable computer such as a notebook, it is related to the usage time of the battery power, which further requires unnecessary power consumption.

In general, the computer uses its own operating system or utility program to detect internal changes such as changes in the video signal output to the monitor or data input by the user's keyboard operation. Screen protection function is added to temporarily close the screen. These screen savers, however, often work on the job, which not only interferes with the job, but can also cause fatal errors in some applications.

In addition, a technique for controlling a monitor power supply by detecting the presence of a user as one of the fundamental measures rather than the screen protection function as described above has been proposed in the past. For example, Publication No. 10-1996-024828 detects the presence or absence of a user using a human body sensor and switches the power of the monitor on and off according to the signal. However, this does not provide a remedy for the human body sensor, so it does not seem feasible. On the other hand, Publication No. 10-1995-031643, 10-1998-036412, 10-1999-085047, 20-1999-005440 and the like uses an infrared sensor as a specific means for detecting the presence of the user.

Infrared sensors, which are mainly used for wireless remote control of home appliances or door luminaires, do not recognize the distance to an object (user), but can detect the presence or absence of a moving object. In addition, the infrared sensor must be able to detect when the object to be detected is greatly moved, and the boundary of the area where the reflected light can be detected is unclear, so it is difficult to accurately set the boundary (distance). Therefore, there are many malfunctions and the reliability of the detection result is very low.

On the other hand, depending on the individual users who are in front of the computer monitor, some people may move very little, while others may not move very much even if they move. As described above, there are technical difficulties in detecting various users with various behaviors without using an infrared sensor as described above, and practically, there are few cases where an infrared sensor is applied to control power saving in the absence of a user.

Therefore, an object of the present invention is to monitor the power supply using an ultrasonic sensor that can accurately determine the presence of the user and cut off the monitor power in the absence of the user by detecting the real-time accurate distance between the monitor and the user using an ultrasonic sensor instead of excluding the infrared sensor. To provide.

1 is a side view showing a monitor for a desktop personal computer to which the present invention is applied and a user's sitting state in front of it.

Figure 2 is a side view showing a desktop personal computer monitor to which the present invention is applied and the absence of the user away from the front.

3 is a circuit diagram of a monitor power control apparatus using ultrasonic waves according to the present invention.

Figure 4 is a plan view showing the main part to explain the principle of distance measurement with the user by the monitor power control apparatus using ultrasonic waves according to the present invention.

5 is an overall flowchart illustrating a power saving control operation of the monitor power control apparatus using ultrasonic waves according to the present invention;

Figure 6 is a detailed flowchart illustrating the detailed operation for the distance measurement during the power saving control operation of the monitor power control apparatus using ultrasonic waves according to the present invention.

Explanation of symbols on the main parts of the drawings

10: ultrasonic transmitter 20: reflected wave receiver

23: signal comparison unit 30: control unit

60: interface

In order to achieve the above object, according to the present invention, an ultrasonic transmission means for converting an electrical signal into ultrasonic waves and radiating them in front of the monitor, and receiving ultrasonic waves reflected from an object in front of the monitor to detect electrical signals therefrom. A power saving control unit for calculating a distance of the object based on the reflected wave receiving means and the electric signal detected by the reflected wave receiving means, and determining the presence or absence of a user according to the calculated distance, and instructing power saving control; In response, a monitor power control device including a power control means for opening and closing the monitor power supply was devised.

As is well known, the frequency of the ultrasonic wave is higher than the audible frequency (generally 20 Hz to 22 KHz) so that it cannot be heard by the human ear. The present invention is to measure the distance between the monitor and the user by using the ultrasonic wave and to determine the presence or absence of the user according to the measured distance to timely power saving control, with reference to the accompanying drawings as a preferred embodiment in detail The explanation is as follows.

1 and 2 show a monitor for a desktop personal computer to which the present invention is applied, and a user state in which the user sits in front of the monitor (FIG. 1) and a member state in which the user has moved away from the seat (FIG. 2), respectively. It is shown. As shown in the figure, the monitor 1 is a power saving control device implemented to control the power of the CRT 3 through the monitor control unit 4 together with the normal CRT 3 and the monitor control unit 4 in the cabinet 2. (5) is built in. The power saving controller 5 calculates the distance of the user by detecting the reflected wave reflected from the user while generating an ultrasonic wave toward the user and according to the calculated distance, the presence or absence of the user, that is, the state of use (FIG. 1) or the absence of the user (FIG. 2), the power saving control is made so that the CRT 3 of the monitor is turned on if it is in use and the CRT 3 is turned off if the user is absent.

In the drawings, an example is given only for a deck top computer, but the present invention will be more useful for a notebook computer in view of the battery life as described above. Typically, notebook computers employ LCDs as their image display means. Therefore, the CRT of the desktop computer monitor as defined above does not exclude the LCD mounted on the monitor of the notebook computer, as well as other flat display means. In addition, in the drawing, the power saving control device 5 is seen as a built-in type to be built into the monitor, it can be configured as an external type, of course.

Referring to FIG. 3, which shows a detailed circuit, the power saving controller 5 according to the present invention includes an ultrasonic transmitter 10, a reflected wave receiver 20, a power saving controller 30, a setting unit 40, and an output unit 50. ), And an interface 60 for serial communication with the monitor control unit 4.

The ultrasonic transmitter 10 includes an oscillator 11 for oscillating a frequency above an audible frequency, a signal generator 12 for modulating an electric signal according to the oscillated frequency, and outputting an ultrasonic drive signal, and a drive signal of the signal generator 12. And a voltage amplifier 13 for amplifying the voltage, and an ultrasonic transmitter 14 for converting the amplified driving signal into ultrasonic waves and transmitting the ultrasonic wave.

The ultrasonic receiver 20 receives an ultrasonic wave received from an ultrasonic transmitter 14 via an object (user) and detects it as an electrical signal, and the electrical signal detected by the ultrasonic receiver 21. The signal amplifier 22 which amplifies the amplitude of the signal is compared with the frequency of the oscillation frequency of the electrical signal used for transmission and the frequency of the electrical signal of the received reflected wave. It is composed of a signal comparator 23 for transmitting to.

The power saving controller 30 continuously or periodically drives the ultrasonic transmitter 10 according to a processing routine (see FIGS. 5 and 6) of a program previously input using various processing mechanisms of a microcomputer, 20) Check the time taken from the ultrasonic transmission to the reception of the reflected wave based on the electrical signal transmitted from 20), calculate the distance of the object (user) according to the checked time, and compare the calculated distance with the set distance Determining whether the monitor is in use or absent the user, and performs a power saving control command to the monitor control unit 4 through the output unit 50 or the interface 60 as a power saving control signal processed according to the determined user presence.

The setting unit 40 is for initializing the operating conditions of the power saving control unit 30 as described above, and is not illustrated in the drawings. For example, the setting unit 40 has a mode setting switch button for operating to switch between the operation mode and the setting mode. Distance control switch buttons are operated to increase or decrease the distance set to a default value for reference by the controller 30. This setting operation is performed by directly transmitting data from the monitor control unit 4 to the control unit 30 through the keyboard operation of the computer using hardware or an external program provided in the computer main body connected to the monitor 1. It will be possible. In this case, the setting unit 40 may be omitted.

The output unit 50 is provided for controlling the monitor power supply or warning, etc., which may also be omitted when directly controlling by serial communication via the interface 60 as described above.

On the other hand, the operating power (Vcc) required for the operation of the control unit 30 may be supplied from the power of the monitor itself in the case of the above-described built-in type, or may be supplied from a separate power source in the case of the external type.

Before explaining the power saving control operation of the monitor power control apparatus using ultrasonic waves according to the present invention implemented as described above with reference to Figure 4 to explain the principle of distance measurement using ultrasonic waves.

When the ultrasonic transmitter 14 of the power saving control device 5 built in the monitor 1 is operated, ultrasonic waves 6 that go straight ahead are radiated, and the radiated ultrasonic waves 6 have an object (user) in front of them. If present, it reflects off its surface and some of the reflected waves 7 reach the ultrasonic receiver 21.

When the time (seconds) transmitted from the ultrasonic transmitter 11 is T1 and the time (seconds) received by the reflected wave receiver 21 is T2, the speed of sound waves in the air at room temperature (25 ° C) is generally 343.2 ㎧, The distance D from the user can be defined by the following equation.

D = 343.2 × (T2-T1) / 2

That is, the distance D can be obtained by dividing the time difference by 2 and multiplying by the sound wave speed. The time difference is divided by two because the ultrasonic transmission distance and the reflected wave reception distance overlap.

The power saving control unit 30 of the power saving control device described above is programmed to measure the distance D with the above calculation algorithm, determine the user presence according to the measurement result, and perform the desired power saving control. 4 and 5 showing the processing routine of the program, the operation of the power saving control field according to the present invention will be described below.

When operating power Vcc is applied to the control unit 30 by turning on the main power of the computer main body or the monitor, the control unit 30 is initialized to the set operating condition (S1), and the ultrasonic transmitter 10 according to the initialized operating condition. ) To generate ultrasonic waves and measure the distance to the user based on the signal detected by the reflected wave receiver 20 (S2). Subsequently, it is determined whether the CRT is currently in an ON state (S3), and if it is in an ON state, it is determined whether the distance measured in the previous step is greater than or equal to the set distance (S4). At this time, if it is not more than the set distance, the user recognizes the state of use and tries again, and determines whether the state has elapsed for a predetermined time while being more than the set distance (S5). In this case, if the measured distance is determined to be longer than the set distance for a predetermined time or more, the user recognizes the absence of the user from the far away position and commands the monitor control unit 4 through the interface 60 described above to supply the CRT power. Turn off (S6).

On the other hand, if the CRT is not currently in the ON state after the distance measurement (S2), that is, it is determined whether the measured distance is within the set distance (S7). At this time, if it is not within the set distance, the user who has moved far away is recognized as a member who has not yet returned, and attempts to measure again with the CRT power off, and determines whether the state has elapsed for a predetermined time while being within the set distance. If it is determined in this manner that the measured distance is still within the set distance for a predetermined time or more, the user recognizes the use state returned to the seat and commands the monitor control unit 4 through the interface 60 described above to turn on the CRT power (S6). )do.

The ON / OFF control of the CRT power supply continues as long as the main power supply, that is, the computer main body or the monitor is not intentionally turned off by the user, thus preventing unnecessary power waste when the user is away from the office for a long time.

Next, Figure 5 shows the subroutine of the distance measuring step (S2) by subdividing, it is used a calculation algorithm defined by the above-described formula. In other words, while transmitting the ultrasonic wave (S21), it is determined in real time whether the reflected wave is received (S22), and when the reflected wave is received, the time and distance taken from the time of the ultrasonic wave transmission to the reflected wave reception point are sequentially calculated (S23, S24), and the ultrasonic wave transmission is performed. If the reflected wave is not received afterwards, the time is counted therefrom to determine in real time whether the counted time exceeds the set time (S25). (S26) and the distance measurement is finished. Here, in the steps of counting and calculating the time (S22, S25), a timer built in the microcomputer constituting the power saving control unit 30 described above may be used, or a built-in timer on the computer main body side may be used.

As described through the above embodiments, the present invention enables the power saving control of the monitor using ultrasonic waves, and unlike conventional attempts to use infrared rays, the user's convenience is reduced to a stable operation with high reliability and low reliability. At the same time, it is effective in reducing the lifespan of the monitor with efficient power management.

In addition to the computer monitor described above, the present invention includes various image display means such as a mobile communication terminal or a television receiver, and can be applied to the same or similarly to any product requiring power saving control depending on the presence or absence of other users.

Claims (3)

Ultrasonic transmitting means for converting an electric signal into an ultrasonic wave and radiating it to the front of the monitor, Reflected wave receiving means for receiving the reflected wave from the transmitted ultrasonic wave reflecting an object in front of the monitor and detecting the electrical signal therefrom, Detecting the reflected wave receiving means A power saving control unit for calculating a distance of the object based on the electrical signal and determining the user presence or not according to the calculated distance, and instructing power saving control; and a power control means for opening and closing the monitor power in response to the power saving control command of the power saving control unit. Monitor power control device using ultrasonic waves provided. The apparatus of claim 1, wherein the reflected wave receiving means includes a signal comparator for transmitting the detected electric signal to the power saving control unit when the frequency of the received reflected wave is compared with the frequency used for the ultrasonic wave transmitting means. Monitor power control device using ultrasonic waves. The monitor according to claim 1, wherein the power control means includes a monitor control unit for directly controlling the power of the monitor under control, and an interface for serial communication between the power saving control unit and the monitor control unit. Power control unit.