JPS586194B2 - Kasaikantiki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fire detector, and more particularly to an oscillating temperature sensing element having a structure in which a temperature sensor such as VO2 whose resistance value changes suddenly depending on the temperature is integrally connected to the oscillating element.

Conventionally, with this type of fire detector, it is usually impossible to determine whether the detector is operating normally in an abnormal situation, and therefore, during testing, an abnormal condition is created and the sensor is examined.

The present invention eliminates the above-mentioned drawbacks, and detects fire by switching the oscillation element when the fire detector normally oscillates and when an abnormality occurs, thereby making it easy to detect fire. be.

Next, the present invention will be explained with reference to examples.

Fig. 1 shows the fire detector of the present invention, in which 1 is a silicon n-type substrate, 2 is a P layer doped with P-type impurities on a part of the substrate 1, and 3 is an n-type silicon layer on P+2. 4 is an n0 layer doped with a high concentration of impurity, 4 is an n0 layer doped with a high concentration of n type impurity on the other part of the 01 substrate, 5 is a layer doped with a high concentration of p type impurity on the other side of the n1 substrate There are 10 layers of P.

These 1, 2, 3, and 4.5 constitute an oscillation element A.

Oxide films (Sin2) 11 and 12 are attached to both sides of A, and a temperature sensor 6 such as VO2 is attached as a thin film on the Si02 film 11, and an element that integrates element A and the temperature sensor is used as an oscillation temperature sensing element. shall be.

Further, the SiO2 film 11 is partially exposed to provide an electrode 7 on the n+3 layer, an electrode 8 commonly used for the n+4 layer and the sensor 6, an electrode 9 on the P+5 layer, and another electrode 10 on the sensor 6.

13 is a light emitting element that displays output.

A power supply ■1 is applied between the electrodes 8 and 7, and a power supply ■2 is applied between the electrodes 9 and 10.

Note that (2) the power supply may be omitted, and the temperature sensor 6 may be attached on the Si02 film 12.

Next, to explain the operation of the device of the present invention, in the configuration shown in FIG. 1, when the temperature is low and the temperature sensor 6 has a high resistance, the potential of the P+5 layer increases due to the injection of holes from the outside, and
If the layer P15 is higher than the layer P+5, n1, P+
2,n”3 cyrisk structure conducts and the light emitting terminal 13
A current flows through.

Then, the potential of the P+5 layer drops to approximately the potential of the n''3 layer.

Since the resistance value of the temperature sensor 6 is so high that it is less than the holding current of Cyrisk, holes are unlikely to come out from the P+5 layer, and when electrons from n+3 enter the P''5 layer, the potential of the P+5 layer When the current decreases, the current flow in the cyrisk structure stops.

However, the n1-P+2 junction remains forward biased until excess carriers are accumulated in the P+2 layer and these carriers are removed. Therefore, n”4,
Since the transistor structures n1, P+2, and n+3 are in a saturated state, a saturated current flows, and when the excess carriers disappear, the current stops completely.

The potential of the P+5 layer remains low, but it gradually rises due to the injection of holes from the outside, and the potential of the P+5 layer remains low.
When the potential of the layer rises above the potential of the 01 layer, the cyrisk structure switches again.

By repeating the above, the oscillation element A oscillates, and the light emitting element 1
3 is supplied with an intermittent current as shown in FIG. 2a.

Next, when the temperature rises, the resistance value of the temperature sensor 6 decreases rapidly, and therefore the cyrisk structure P+5, nIpP+2
When pn+3 is turned on, the current becomes higher than the holding current, and Cyrisk continues to be conductive.

Then, this sirisk current and the saturation current due to the transistor structure continue to flow, and the light emitting element 13 has almost the power supply voltage V.
, a voltage of , is applied.

This situation is shown in FIG. 2b.

That is, when the temperature is low, an oscillation output is produced, and when the temperature is high, a large switched current flows (see FIG. 2C).

Therefore, when the temperature is low, the light emitting element blinks or appears dimly lit, and as the temperature rises,
When an abnormality occurs, a large current flows through the light emitting element, making it extremely bright.

In the present invention, as mentioned above, under normal conditions, an oscillating current flows through the light emitting element, causing the element to blink, and when the temperature rises and an abnormal state occurs, a large current flows through the light emitting element, resulting in a very It becomes brighter.

Therefore, the flashing state indicates that the sensor is working without any abnormality, and there is no need to check the operation of the sensor, and in the event of an abnormality, the bright light illuminates, which has the effect of alerting you to a fire.

FIG. 3 shows another embodiment of the present invention, and the temperature sensor may not be a thin film but may be beet-shaped.

An example thereof is shown in FIG. In FIG. 3, 14 is an electrode of a temperature sensor.

[Brief explanation of the drawing]

Fig. 1 is an embodiment of the fire alarm of the present invention, Fig. 2 a and b
, c are operation explanatory diagrams, and FIG. 3 shows another embodiment of the present invention. 1...Substrate, 2...P+ layer, 3...
...n+ layer, 4...n+ layer, 5...
P+ layer, 6...sensor, 7, 8, 9, 10.
...Electrode, 11,12...Sin2 film,
13... Light emitting element, 14... Electrode.

Claims (1)

[Claims] 1. An impurity layer 2 of a conductivity type opposite to that of the substrate is provided on a part of one side of a conductivity type semiconductor substrate 1, and a substrate 1 is further provided on the impurity layer 2.
An impurity layer 3 of the same conductivity type as that of the substrate 1 is provided on another part of one side of the substrate 1, an impurity layer 5 of the opposite conductivity type to that of the substrate 1 is provided on the opposite side of the substrate 1, In the oscillation element in which the electrodes 7, 8.9 are provided on the layers 3, 4, 5,
The temperature sensor 6 and the power supply V2 are connected in series between the electrodes 8 and 9, and the power supply V and the display element 13 are connected in series between the electrodes 8 and 9.
A fire detector connected between 7.