JPS61264977A - Television receiver - Google Patents

Abstract

PURPOSE:To provide warning by detecting the distance between a viewer and the receiver and by controlling the operational state of the receiver in case the viewer approaches closer than a specified distance. CONSTITUTION:Assuming the distance L(m) is taken for the specified distance to demand for the control of the operational state of the receiver to protect the viewer's eyes, the time t(sec) from the twice when the ultrasonic wave is emitted by a transmitting means 1 untill the time when the reflecting signal is received by a receiving means 2 t(sec) can be expressed as: t=2XL/V. By so setting the pulse width t2 from a monostable multivibrator 31 that the t3 made by adding the width t1 of the pulse from an oscillator circuit 11 to the t2 equals to the time t(sec), whether or not the distance between the viewer and the display surface is the distance that needs the control of the operational state of the picture tube, can be decided by using the output from a gate circuit 32. In case where the output wave form of an integration waveform trimming circuit 33 is the one shown by (f), a signal (g) is generated in the output of a gate 32, and the operational state of the receiver is executed, and the warning is given to the viewer.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a television receiver.

Conventional technology TV is a system that targets moving images such as sports competitions, but the visual system cannot follow fast movements, and viewing fast-moving images too close can cause dizziness and fatigue. (For example, Takashi Fujio, "The Future of Broadcasting and High-Definition Television," November and December 1980, NHK Giken Monthly Report, p. 435).

Furthermore, in television, viewers are passive, which imposes restrictions on viewing distance and movement of the two points of interest, which can lead to viewer fatigue. The viewing distance from the display surface and the lateral spread angle are the factors that determine the range of the observation position, but the optimal viewing distance is determined by the characteristics of the focus adjustment to the display surface, and the characteristics of the adjusted resting position and depth of focus. from 1
Observing from a distance of ~2 m or more places less burden on the adjustment mechanism (Hatata, Sakaide, "Visual Psychology and Display", Vol. 31, No. 4, 1977, Television, P2S5).

Furthermore, conventional television receivers did not have a function to measure the distance between the viewer and the display screen.

Problems to be Solved by the Invention In such conventional television receivers, when a viewer approaches the display screen within the above-mentioned distance and observes it, eye fatigue becomes a problem. In particular, there was a risk of adverse effects on the eye health of growing infants and children.

In view of the above, the present invention has a simple configuration that detects the distance between the television receiver and the viewer, and controls the operating state of the television receiver when the viewer approaches and observes the television receiver within a set distance. , aims to provide a television receiver that gives a warning.

Means for Solving the Problems In order to solve the above problems, the present invention provides a transmitting means for emitting a signal, a receiving means for receiving a reflected signal of the signal emitted by the transmitting means, and an output of the receiving means. from,
The apparatus includes a detection means for detecting the distance between the television receiver and the viewer, and a control means for controlling the operating state of the television receiver based on the output of the detection means.

Operation The present invention, with the above-described configuration, can prevent eye fatigue caused by a viewer observing the display screen of a television receiver by approaching within the above-mentioned distance.

Example FIG. 1 is a block diagram showing one embodiment of the present invention.

In FIG. 1, 1 is a transmitting means, and an oscillation circuit 11,
It has an oscillation circuit 12, a drive circuit 13, and a speaker 14, and the signal emitted from the transmitting means 1 is an ultrasonic wave. 2
is a receiving means and includes a microphone 21 and an amplifier circuit 22. 3 is a detection means, which includes a monostable multivibrator 31, a gate circuit 32, and an integral waveform shaping circuit 33; 4 is a control means. The oscillation circuit 11 generates a rectangular wave as shown in FIG. The oscillation circuit 12 has an oscillation period controlled by the oscillation circuit 11, and generates a burst pulse as shown in FIG.

The oscillation frequency of this oscillation circuit 12 becomes the frequency of the emitted ultrasonic waves. The output of the oscillation circuit 12 is supplied to a drive circuit 13, and the drive circuit 13 drives a speaker 14.

In this way, the speaker 14 emits ultrasonic waves intermittently. The ultrasonic waves emitted from the speaker 14 are reflected by the viewer, and the reflected signal is received by the microphone 21.

The speaker 14 and the microphone 21 are designed for ultrasonic waves, and those using piezoelectric ceramics, for example, have been put into practical use. The reflected signal converted into an electrical signal by the microphone 21 is shown in FIG. 2C. This signal is amplified by the amplifier circuit 22, integrated and waveform-shaped by the integral waveform shaping circuit 33. The output waveform of the integral waveform shaping circuit 33 is shown in FIG. 2d.

On the other hand, the output of the oscillation circuit 11 is also supplied to the monostable multivibrator 31. The monostable multivibrator 31 generates a rectangular wave as shown in FIG. 2e.

The outputs of the monostable multivibrator 31 and the integral waveform shaping circuit 33 are supplied to a gate circuit 32. In the gate circuit 32, the outputs of the monostable multivibrator 31 and the integral waveform shaping circuit 33 are ANDed, and the output of the gate circuit 32 is supplied to the control means 4.

By the way, the sound velocity V (m/sec) of ultrasonic waves is determined by the temperature T
("C), it is expressed as V = 331 + 0.67. To prevent eye fatigue, the distance between the display surface that controls the operating state of the television receiver and the viewer is L (1rL). Then, the time t (sec) from when the ultrasonic wave is emitted by the transmitting means 1 to when the reflected signal is received by the receiving means 2 is expressed as t=2xL/V.Therefore, the monostable multivibrator 3
If t is set to 2k so that t3, which is the sum of the pulse width t2 of 1 and the pulse width t1 of the oscillation circuit 11, is equal to 2k, the distance between the display surface and the viewer is determined by the output of the gate circuit 32. It can be determined whether the distance is sufficient to control the operating state of the television receiver.

In other words, when the output waveform of the integral waveform shaping circuit 33 is as shown in FIG.
Similarly, in the case of FIG. 2 f, it can be seen that the distance between the display surface and the viewer is within the set distance range. Therefore, in the latter case, the output of the gate circuit 32 generates the signal shown in FIG. 2q, which controls the operating state of the television receiver and provides a warning to the viewer.

FIG. 3 shows an example of a circuit configuration for cutting off audio output by the control means. The audio amplification circuit 41 is supplied with an audio signal from a terminal 42, but by providing a transistor 43 and driving the base of the transistor 43 with the signal shown in FIG. 2q, the audio output is cut off and an alarm is issued. give.

FIG. 4 shows an example of a circuit configuration for reducing the audio output by the control means, and FIG. 5 shows an example of the circuit configuration for increasing the audio output. It is also possible to change the brightness or contrast of the screen using the control means. Additionally, transistor 43 can be used to change the synchronization state of the deflection circuit and control it to disturb horizontal or vertical synchronization. Furthermore, it is also possible to control the image so that the color signal is cut off and a black and white image is created.

Incidentally, in the embodiment shown in FIG. 1, the case where the speaker 14 and the microphone 21 are installed separately has been illustrated and explained, but a speaker/microphone type has also been put into practical use, and this dual-purpose type speaker/microphone can be used. Needless to say, the same effect can be obtained.

FIG. 6 shows a block diagram of another embodiment of the invention. The transmitting means 1, the receiving means 2, and the detecting means 3 operate in the same manner as in the embodiment shown in FIG. Reference numeral 6 denotes an alarm means, which is driven by the output of the detection means 3 and issues an alarm to indicate that the distance between the television receiver and the viewer is within a set range. FIG. 7 shows an embodiment of the alarm means 5. 6
Reference numeral 1 denotes an oscillation circuit that generates an audible frequency signal, and the detection means 3 controls starting and stopping of the oscillation. The output of the oscillation circuit 51 is supplied to an audio amplification circuit 62, and an alarm is emitted from a speaker (not shown). FIG. 8 shows another embodiment of the alarm means 6.

53 is a voice synthesis circuit, and the voice signal generated by this voice synthesis circuit 63 is supplied to a voice amplification circuit 62, and an alarm is emitted from a speaker (not shown).

FIG. 9 shows still another embodiment of the alarm means 6.

Reference numeral 64 denotes a character signal generation circuit controlled by the detection means 3, and the character signal generated by the character signal generation means 54 is amplified by the video amplification circuit 56 and displayed on the screen to issue an alarm. It is also possible to give a warning by generating and displaying a graphic signal instead of a character signal in the character signal generating means 64.

FIG. 10 shows a configuration diagram of still another embodiment of the present invention. 15 is a light emitting element, and 16 is a condensing lens, which forms a transmitting means. 23 is a light receiving element, 24 is a condensing lens,
forming a receiving means. 61°62.63 is a viewer, and if the viewer's position is closer to the light emitting element 16 than the viewer 61 (closer to the display surface), an alarm is issued, and if the viewer 61 is also farther from the display surface. is set not to issue an alarm. Therefore, an alarm is emitted at the viewer's 62 position, but no alarm is emitted at the viewer's 63 position.

Next, the operation will be explained. The light emitting element 16 uses, for example, an infrared light emitting diode, and the emitted infrared light is transmitted through the condensing lens 1.
The light is focused at 6 and hits the viewer 61. The infrared light reflected by the viewer 61 enters the condenser lens 24, is condensed, and is received by the light receiving element 23. An example of the structure of the light receiving element 23 is shown in FIGS. 11 and 12. In this example, 2 of A and B
It is composed of split photodiodes 28 and 29, and the infrared light reflected by the viewer e1 enters the light receiving position 25. At this time, currents 11 and I2 flowing through photodiodes 28 and 29 are equal.

As shown in the block diagram of this embodiment in FIG. 13, the light receiving element 23 is connected to a detection means 34.

The detection means 34 compares the currents of the photodiodes 2 and 29, and is set to generate an output and drive the control means 4 when the current I2 flowing through the photodiode 29 is larger than the current 11 flowing through the photodiode 28. ing. Therefore, when the infrared light reflected by the viewer 61 enters the light receiving position 26, the detection means 34 does not generate an output and does not issue an alarm.

Next, when the viewer 63 is observing at the position shown in FIG. 10, the infrared light reflected by the viewer 63 enters the light receiving position 27.

In this case, 11 is the work. , so no alarm is issued. Next, when the viewer 62 is observing at the position shown in FIG. 10, the infrared light reflected by the viewer 62 enters the light receiving position 26. In this case I2 is 11
, so that the sensing means 34 generates an output and drives the control means 4. The control means 4 is capable of issuing an alarm to the viewer, as described in detail in the description of the embodiment shown in FIG.

By the way, the distance between the condensing lens 16 and the viewer 61 is
If the distance between the light emitting element 16 and the condensing lens 16 is C5, the distance between the condensing lenses 16 and 24 is E, and the distance between the condensing lens 24 and the light receiving element 23 is F, then C, E, and F can be set as appropriate. By selecting , the distance between the display surface that issues the alarm and the viewer can be arbitrarily set.

As described above, it is possible to measure the distance between a television receiver and a viewer with a simple configuration using ultrasonic waves, infrared rays, or the like. In particular, those using ultrasonic waves can widen the directivity angle. (There is data showing performance of ±46° or better) Therefore, it is possible to detect not only the front of the television receiver, but also the viewer who is observing diagonally from below. In addition, since measurements are made at short distances of 1 to 2 meters, ultrasonic waves, which propagate at a slower speed than light, are used to enable highly accurate measurements, and there are no malfunctions caused by audible sounds.

Moreover, since the light-emitting element and light-receiving element are small, those using infrared rays can be constructed compactly, and the degree of freedom in the design of the television receiver is improved. Furthermore, the circuit configuration is simple and power consumption is low.

In an embodiment in which the audio output is controlled by a control means, an embodiment in which the brightness and contrast of the screen are changed, an embodiment in which the deflection is desynchronized, and an embodiment in which the screen is made into a black and white image.
The system is simple in structure because it issues an alarm by changing the operating state of the television receiver without providing any special alarm means.

In addition, in embodiments having an oscillation circuit as an alarm means, embodiments having a voice synthesis circuit, and embodiments having a character or graphic signal generation circuit, sounds and characters that are not generated or displayed on the original television receiver may be used. Or, since the warning is given as an image, the warning action for the viewers is more effective.

Effects of the Invention As described above, according to the present invention, in order to prevent eye fatigue caused by a viewer observing a television receiver too close, The means for giving a warning can be realized with a simple configuration and with high precision, and is extremely useful in practice.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a waveform diagram for explaining the operation of the block diagram showing one embodiment of the present invention shown in FIG. 1, and FIGS. 6 and 6 are block diagrams showing control means in one embodiment of the present invention, FIG. 6 is a block diagram showing another embodiment of the present invention, and FIG.
8 and 9 are block diagrams showing an embodiment of the alarm means in another embodiment of the present invention shown in FIG.
FIG. 10 is a configuration diagram showing still another embodiment of the present invention, FIGS. 11 and 12 are structural diagrams and wiring diagrams showing an example of the light receiving element in the embodiment of the present invention shown in FIG. 10,
FIG. 13 is a block diagram showing the embodiment of the invention shown in FIG. 10. 1... Transmission means, 2... Receiving means, 3
...Detection means, 4...Control means, 6.
...Alarm means, 51...Oscillation circuit, 53
...Speech synthesis circuit, 64...Character signal generation circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure 4 Figure 5

Claims (11)

[Claims] (1) A transmitting means for emitting a signal, a receiving means for receiving a reflected signal of the signal emitted by the transmitting means, and a detection method for detecting the distance between the television receiver and the viewer from the output of the receiving means. 1. A television receiver, comprising: a control means for controlling the operating state of the television receiver based on the output of the detection means. (2) the signal emitted by the transmitting means is an ultrasonic wave;
The television receiver according to claim 1, wherein the distance between the television receiver and the viewer is detected from the time from when the signal is emitted to when the reflected wave is received. (3) The transmitting means is an infrared emitting means that emits infrared rays outward from the housing when receiving a television image, and the receiving means is an infrared receiving means disposed at a certain distance from the infrared emitting means. 2. The television receiver according to claim 1, wherein the television receiver performs triangulation to detect the distance between the television receiver and the viewer based on the position where the reflected signal is incident on the infrared receiving means. (4) The television receiver according to claim 1, wherein the control means controls to reduce, cut off, or increase the audio output. (5) The television receiver according to claim 1, wherein the control means controls to change the brightness or contrast of the screen. (6) The television receiver according to claim 1, wherein the control means controls the deflection to be out of synchronization. (7) A television receiver according to claim 1, wherein the control means cuts off color signals on the screen and controls the image to be black and white. (8) A transmitting means for emitting a signal, a receiving means for receiving a reflected signal of the signal emitted by the transmitting means, and a detection for detecting the distance between the television receiver and the viewer from the output of the receiving means. and an alarm means that is driven by the output of the detection means and generates an alarm. (9) The television receiver according to claim 8, wherein the alarm means includes an oscillation circuit, and generates the alarm by supplying the output of the oscillation circuit to the audio circuit of the television receiver. (10) The television receiver according to claim 8, wherein the alarm means includes a voice synthesis circuit, and generates the alarm by supplying the output of the voice synthesis circuit to the voice circuit of the television receiver. (11) The television receiver according to claim 8, wherein the alarm means has a character or graphic signal generation circuit, and generates the alarm by displaying the output of the character or graphic signal generation circuit on the screen. .