GB2105889A - Television viewing distance warning device - Google Patents

Abstract

A television viewing distance warning device, for urging TV watchers to maintain an appropriate distance from the TV, comprises a detecting device capable of producing an electrical signal in response to a person coming within a predetermined range from a TV set, an amplifying unit for amplifying the electrical signal produced by the detecting device, a relay unit operable by the amplified electrical signal, and a disturbing unit operable by the relay unit for causing the picture on the TV screen to be interfered, or to become fuzzy, or to disappear. The device brings the TV picture back to normal as soon as the person moves out of the predetermined range.

Description

SPECIFICATION Television viewing distance warning device Nowadays television (hereinafter as TV) has become indispensable in daily life. People, particularly children, can almost not live without them. However, children tend to come undesirably close to the TV when watching an exciting program, which closeness may then be hazardous to their eyes.

In view of the aforesaid problem this invention offers a novel device that is adapted to cause the picture on the TV screen to be interferred, to become fuzzy or to disappear when the person watching the TV comes too close to the TV, so as to urge the person to keep an appropriate distance from the TV.

The present invention will be further described with reference to the accompanying drawings, in which: Figure 1 is a block diagram of an embodiment of the device of this invention.

Figure 2 is an electrical circuit diagram of the embodiment shown in Fig. 1.

Figure 3 is an electrical circuit diagram of an alternative to the disturbing unit shown in Fig. 2.

Figure 4 is an electrical circuit diagram of another alternative to the disturbing unit shown in Fig. 2.

In Fig. 1 there is shown a block diagram of an embodiment of this invention. In the drawing, 1 is a detecting device placed in the vicinity of an TV set, which comprises an ultrasonic wave producing unit 1A and an ultrasonic wave receiving unit 1 B; 2 is an amplifying unit, 3 is a relay unit and 4 is a disturbing unit. An ultrasonic wave is produced and transmitted by the ultrasonic wave producing unit 1A, which ultrasonic wave is reflected by a a person within a predetermined range from the TV set, and is theri received by the ultrasonic wave receiving unit 1 B wherein the ultrasonic wave is converted into an electrical signal which is amplified by the amplifying unit 2 and then applied to the relay unit 3. Disturbing unit 4 then activated by the relay unit 3 as soon as the amplified electrical signal is applied to the relay unit 3.

Fig. 2 shown as electrical circuit diagram of a preferred embodiment of the device of this invention. As shown in the drawing, ultrasonic wave producing unit 1A comprises a transistor Q1, a transformer T, having a primary coil L, and a secondary coil L3, an ultrasonic wave transmitter Z, connected cross the seconary coil L2 through a capacitor C3, two bias resistors R, and R2 in series connection which are connected across a power source E having a (+) lead and a (-) leads, the power source may be either a battery, or a AC-DC converter or a rectifier connected to a AC source; transistor Q, having a base connected to the junction of two bias resistors R, and R2 through a resistor R and another secondary coil L2 electrically inductively to primary coil L, so as to form a feed back circuit, a collector connected to a tap drawn from the primary coil L1, and an emitter connected to the (-) lead through a resistor R3. A capacitor C2 is connected across the primary coil L, to form a resonant circuit. SW, is a switch through which electrical power from the power source E is supplied to the entire circuit of the device. As soon as switch SW, is closed, the ultrasonic wave producing unit 1A is energized and an ultrasonic wave is transmitted from the ultrasonic wave transmitter Z,.

Ultrasonic wave receiving unit 1 B comprises a matching transformer T2 having a primary coil L4 and a secondary coil L6, and an ultrasonic wave receiver Z2 connected across the prinmary L4 through capacitor C4. A capacitor C6 is connected across the secondary coil L5 to form a resonant circuit which is connected to the (-) lead. A tap is drawn from the secondary coil L5 to be connected to an IC through capacitor C6. Ultrasonic wave transmitted by Z, is reflected by a person within the predetermined range, and received by the ultrasonic wave receiver Z2. The received ultrasonic wave is then converted into an electrical signal by the matching transformer T2 and fed to amplfying unit 2 to be described below.

Amplifying unit 2 comprises an amplifying IC1, which may be Sanyo LA3072, transistors Q,, Q3 Q4 and Q5 cooperatively connected with said IC, and capacitors C10, C11, C,2 C,3 and C14, a diode D1, a variable resistor R11, resistors R6 R7 R8 R9, Rro, R,2 R,3 and R,4 shown in the drawing, so as to amplify in multiple stages the electrical signal produced by the ultrasonic wave receiving unit 1 B.The amplifying unit 2 is also provided with decoupling capacitors C7 and C8 and a resistor R5 and a capacitor C9 connected as shown in Fig. 2 to prevent the unit from being disturbed by the oscillation performed by the circuit. Variable resistor R" is adapted to adjust the sensitivity of the unit so that the effective range of the device of this invention can be predeterminedly adjusted. Transistors Q4 and Qs constitute a last stage of the amplification, in which the collectors of transistors 04 and Q5 are jointly connected to a first relay RL, of relay unit 3 so that first delay R1 is activated by the amplified electrical signal.

Relay unit 3 comprises a first relay RL, having a first contact point rl, connected to a second relay RL2 through a light bulb W. First relay RL, is operable by the amplified electrical signal as mentioned above. Second relay RL2 is provided with a second contact point rI2 to be connected to a disturbing unit to be described below. First contact point r11 is normally open but is closed as soon as first relay RL, is activated by said amplified electri cal signal. As soon as first contact point r11 is closed, second relay RL, is activated to close the second contact point rI1 which is also normally open, and in the meantime the light bulb is turned on.

It is to be understood that second contact point r12 can be modified to become normally closed and to be opened when second relay RL2 is activated as in the alternative arrangements described below.

In a preferred embodiment shown in Fig. 2, disturbing unit 4 comprises an electric motor M, which may be a motor built in a toy that can be placed in the vicinity or on top of the TV set. Electric power is supplied to motor M through second contact point tri2, which is normally open. As soon as first relay RL, is activated, second relay RL2 is activated accordingly to close second contact point r12 so as to energize the motor M, which is then rotated and a high frequency, random wave capable of interferring the picture on the TV screen is produced. The TV picture remains interferred as long as the person remains in the predetermined range and the device of this invention remains functioning as described above.

As soon as the person moves out of the predetermined range, the ultrasonic wave receiving unit will no longer produce an electrical signal and the first relay RL1 is accordingly de-energized so as to reset second relay RL2, thus causing the motor M to stop and bringing the TV picture back to normal.

The disturbing unit 4 shown in Fig. 2 can be replaced by an alternative means as shown in Fig. 3. In this arrangement second contact point r12 of second relay RL2 is normally closed and the antenna for the TV set is connected through the second contact point r12 to the TV set. In normal operation while no person is within the predetermined range, the TV set, having the antenna connected properly, produces normal pictures on the screen.

As soon as a person comes within the predetermined range, the device of this invention functions and the antenna is disconnected thus causing the picture on the TV screen to become fuzzy. As soon as the person moves out of the predetermined range the connection of the antenna to the TV set is restored again and the picture on the TV screen is brought back to normal.

Fig. 4 shows another alternative to the disturbing unit 4 shown in Fig. 2. In this arrangement second contact point rI2 is normally closed and used to connect the TV set to power supply source. When second relay RL2 is activated as a person comes within the predetermined range the second contact point rI2 is caused to open thus disconnecting the supply of the power to the TV set. As soon as the person moves out of the predetermined range the second relay RL2 is de-energized to reset and to close second contact point tri2, thus resuming the supply of power to the TV set.

Although preferred forms of the present invention have been illustrated and described, it is understood, that numerous modifications can be made otherwise without departing from the principles of this invention. For example, the ultrasonic wave producing unit and ultrasonic wave receiving unit may be replaced by an induction device, or an infrared ray apparatus capable of producing an electrical signal in response to the entry of a person into a predetermined range from a TV set.

Therefore, the scope of this invention is to be defined by the appended claims.

Claims (5)

1. A television viewing distance warning device, comprising: a detecting device (1) adapted to produce an electrical signal in response to the entry of a person into a predetermined range from a TV set; an amplifying unit (2) adapted to amplify said electrical signal; a relay unit (3) electrically operable by said electrical signal amplified by said ampifying unit; and disturbing means (4) electrically operable by said relay unit for causing a picture on a TV screen to be interferred, to become fuzzy or to disappear.

2. A television viewing distance warning device of Claim 1, wherein said detecting device (1) comprises: an ultrasonic wave producing unit (1A) capable of producing an ultrasonic wave that can reflected by a person, and an ultrasonic wave receiving unit (1 B) capable of receiving said ultrasonic wave reflected by a person within a predetermined range and converting said ultrasonic wave into an electrical signal.

3. A television viewing distance warning device of Claim 1, wherein said disturbing means (4) comprises a switch means through which an antenna is connected to a TV set, said switch means being normally closed and operable by said relay unit to become open when said relay unit is activated by said electrical signal.

4. A television viewing distance warning device of Claim 1, wherein said disturbing means (4) comprises: a switch means and an electrical motor to which electrical power is supplied through said switch means; said switch means being normally open but operable by said relay unit to become closed when said relay unit is activated by said electrical signal.

5. A television viewing distance warning device of Claim 1, wherein said disturbing means (4) comprises a switch means through which electric power is supplied to the TV set, said switch means being normally closed and operable by said relay unit to become open when said relay unit is activated by said electrical signal.