JPH0735476Y2 - Phone hook detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a hook detector for a telephone.

[Conventional technology]

A conventional hook detector of a telephone uses a microswitch or the like. When a handset is placed on a stand, a microswitch provided on either the handset or the stand is pressed, and hook detection is performed by turning on / off the microswitch. I was going.

[Problems to be solved by the device]

Since the conventional hook detector of the above-mentioned telephone uses the mechanical contact of the micro switch, it has a limited life and may malfunction if it is vibrated or shocked especially when it is off-hook. There is a drawback that it is difficult to make a drip-proof / dust-proof structure because there are parts. Further, there is a drawback that the user may accidentally press the hook switch of the micro switch while using the handset.

[Means for Solving the Problems]

A hook detector of a telephone of the present invention is a telephone provided with a handset, wherein a light receiving element and a light emitting element are provided in each of the handset and the stand of the handset,
A pattern generation circuit for generating and transmitting at least one preset pattern signal to the light emitting element is provided in the stand, and a pattern detection circuit for detecting the pattern signal from the light receiving element is provided in the handset. is doing.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a vertical sectional view of a telephone to which an embodiment of the present invention is applied.

In FIG. 1, the telephone set to which the present embodiment is applied is a stand 1
A handset 2 and a curl cord 3 connecting the two, and when the handset 2 is placed on the stand 1, the light emitting diode 4 is placed on the stand 1, and the handset 2 is placed on the stand 1. A phototransistor 5 is attached.

When the handset 2 is placed on the stand 1 as shown in FIG. 1, in a so-called on-hook state, the light emitted from the light emitting diode 4 reaches the phototransistor 5. The light of the light emitting diode 4 does not reach the phototransistor 5 when the handset 2 is lifted in a so-called off-hook state.

FIG. 2 is a block diagram showing an embodiment of the present invention applied to the telephone shown in FIG.

In FIG. 2, in the present embodiment, the output of the pattern generating circuit 6 in the cradle 1 is connected to the light emitting diode 4, and the light emitting diode 4 is turned on / off according to the pattern signal generated by the pattern generating circuit 6. The light emitting diode 4 emits light in a pattern according to the generated pattern signal. On the other hand, the output of the phototransistor 5 in the handset 2 is connected to the pattern detection circuit 9. The resistor 7 is a current limiting resistor of the light emitting diode 4, and the resistor 8 is an output (load) resistor of the phototransistor 5.

Next, the operation of this embodiment will be described with reference to FIG. 1 and FIG.

Here, if the detection pattern signal of the pattern detection circuit 9 is set to be the same as the generation pattern signal of the pattern generation circuit 6, the light emitting diode 4 and the phototransistor 5 face each other when the handset 2 is placed on the stand 1. As a result, both are in an optically coupled state. Therefore, the input of the light emitting diode 4, that is, the output pattern of the pattern generation circuit 6 appears at the output of the phototransistor 5, that is, the input of the pattern detection circuit 9, and accordingly, the "detection" state is output as the detection output of the pattern detection circuit 9. . On the other hand, when the handset 2 is not on the stand 1, the light emitting diode 4 and the phototransistor 5 are disconnected, the pattern signal generated by the pattern generation circuit 6 does not reach the pattern detection circuit 9, and the detection output is It becomes "non-detection".

According to the above description of the operation, if the detection output of the pattern detection circuit 9 is in the "detection" state, the handset 2 is in a so-called on-hook state in which the handset 2 is placed on the stand 1. Conversely, if "non-detection", the handset 2 is in the stand. It is possible to perform hook detection of being in a so-called off-hook state in which the hook is lifted from 1.

By the way, in the off-hook state, various kinds of light are input to the phototransistor 5 from the surroundings. However, since the input light at that time is not the output light of the light emitting diode 4, the set pattern signal appears at the output of the phototransistor 5. No, so it does not detect on-hook.

Here, if the light emitted from the light emitting diode 4 is selected as visible light, the user can confirm the position of the stand 1 on which the handset 2 should be placed when the telephone to which this embodiment is applied is used in the dark.

Further, by sealing the surfaces of the light emitting diode 4 and the phototransistor 5 with acrylic glass or the like, a dustproof / dripproof structure can be obtained without impairing the hook detection function.

[Effect of device]

As described above, according to the present invention, stable hook detection can be performed by detecting whether or not a preset pattern signal is transmitted between the light emitting element and the light receiving element. In addition, since it has no moving parts, it has a longer life and higher reliability than before, and has the effect of making the phone dust- and drip-proof.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a telephone to which an embodiment of the present invention is applied, and FIG. 2 is a block diagram showing an embodiment of the present invention applied to the telephone shown in FIG. 1 ... Stand, 2 ... Handset, 3 ... Curl code, 4
... light emitting diode, 5 ... phototransistor, 6 ... pattern generating circuit, 7,8 ... resistor, 9 ... pattern detecting circuit.

Claims (1)

[Scope of utility model registration request] 1. In a telephone having a handset, a light receiving element and a light emitting element are provided in each of the handset and a stand of the handset, and at least one pattern signal preset to the light emitting element is provided in the stand. A hook detector for a telephone, comprising a pattern generating circuit for generating and transmitting, and a pattern detecting circuit for detecting the pattern signal from the light receiving element in the handset.