JPS5832550B2 - TV screen proximity warning device - Google Patents

Description

[Detailed Description of the Invention] One of the recent social problems is myopia among elementary and junior high school students.

Although this tendency for myopia to increase may be due to multiple factors in learning time, it cannot be denied that this tendency is already present in young children.

One of the causes of myopia is television (hereinafter simply referred to as television).

That is, with the spread of televisions, this is caused by people getting closer to the television and looking at its screen.

The present invention was made in order to alleviate the above-mentioned harmful effects caused by televisions, and the purpose of the present invention is to issue an alarm with a buzzer or cut off the power to the television if the person approaches the television screen. This relates to a device for

Hereinafter, the present invention will be explained with reference to FIGS. 1 and 2. FIG. 1 shows modulated light on a television screen.

As is well known, this modulated light has a scanning frequency f (15750
Hz) and the field frequency (60 Hz) as shown in the figure, and the reflected light is input to the light receiving element 10 shown in FIG.

However, since the amount of reflected light from the TV screen is not necessarily constant and varies in various ways, using only this reflected light as input to the light receiving element 1 is not suitable for the operation of the device of the present invention. It is unstable.

In order to solve this instability, a so-called auxiliary light source with a constant light amount is required.

Of course, this auxiliary light source emits modulated light having the same frequency as the scanning frequency (15,750 Hz), and the reflected light is input to the light receiving element 1 together with the modulated light from the television screen.

FIG. 2 shows a block diagram of the invention.

In the figure, numerals 8 and 10 represent a television and a person watching it, respectively.

As shown in the figure, when the person approaches the screen of the television 8 within a certain distance, the modulated light on the screen of the television 8 and the
The modulated light of the auxiliary light source 9 projected radially from above or in the vicinity thereof is reflected by the auxiliary light source 1o and input to the light receiving element 1.

The light receiving element 1 receives surrounding natural light in addition to the modulated light and outputs it to the amplifier 2. The amplifier 2 is equipped with an automatic bias control circuit to control its output according to the external noise of the surroundings. ing.

The output of the amplifier 2 is sent to a filter 3 that passes only frequencies around the scanning frequency (15750Hz).
The signal is then integrated by the rectifier/integrator circuit 4.

That is, this filter 3 is for extracting only the component of the modulated light, and the rectifier/integrator circuit 4 is for integrating the current of the above component.

In this way, as the screen of the television 8 is approached, the output of the above integral increases gradually, and the Schmitt circuit 5 finally operates at a specific output point.

This Schmitt circuit 5 activates an alarm circuit 7 via a relay circuit 6, etc., so that the alarm circuit 7 works to sound a buzzer or to cut off the power to the television 8.

This allows those who watch TV 8 to easily know what's going on even if they get close.

The time constant for the integration of the rectifier/integrator circuit 4 is selected appropriately so that the Schmitt circuit 5 etc. will not operate when switching channels, etc., and if possible, this device should be connected to the light receiving element 1. It is desirable that everything other than the auxiliary light source 9 be provided within the television 8 device.

Moreover, there is no problem with cans, etc., even if it is installed at the top, bottom, or side of the device.

As described above, according to the present invention, if you are approaching the TV screen, the buzzer sounds and the power to the TV is cut off, so it is easily recognized that you are approaching the TV screen, and the buzzer then sounds the TV screen. (
・For example, you may have to turn the TV back on.
It has a great effect on the psychology of the viewer.

Furthermore, according to the present invention, in conjunction with the modulated light of the television screen,
Since an auxiliary light source is provided, the operation of the device is more reliable.

[Brief explanation of the drawing]

FIG. 2 shows a block diagram of the present invention, and FIG. 1 shows the modulated light on the television screen in FIG. 1: Photodetector, 2: Amplifier, 3: Filter 4: Rectifier
Integral circuit, 5: Schmitt circuit, 6: Relay circuit, 7:
Alarm circuit, 8: TV, 9: Auxiliary light source.

Claims (1)

[Claims] 1. Amplify the sensitivity of the light-receiving element that receives the reflected light from the TV screen modulated light and the modulated light from the auxiliary light source by keeping it constant using an amplifier with an automatic bias control circuit, and use the output of the amplifier to adjust the modulation frequency of the reflected light. A television screen characterized in that the Schmitt circuit rectifies and integrates the signal through a filter, and when the integrated output reaches a certain value, the Schmitt circuit activates an alarm circuit having a hood or the like via a relay circuit or the like. proximity warning device