JPS617429A - Electronic clinical thermometer - Google Patents

Abstract

PURPOSE:To simplify the circuit constitution by commonly operating a sensor, which detects bodily temperature, and an element, which drives a buzzer, by one transistor. CONSTITUTION:By the output of a control circuit 23, the collector and the emitter of a transistor Tr 22 are shorted. The base and the collector of a transistor Tr 1 are shorted. Under this state, the transistor Tr 1 starts temperature measurement. A temperature measuring circuit 24 amplifies a voltage cooresponding to the temperature, which is detected by the transistor Tr 1. The result is converted into the bodily temperature by an operation circuit 25. The temperature is added to a display driving circuit 26 and displayed on a display circuit 6. When a report is announced by a buzzer, a control pulse, which releases the shorted state of the transistor Tr 22, is sent from the control circuit 23. This operation is intermittenetly performed, and energy is stored in a coil 4. Thus a buzzer sound is generated by the resonance with a piezoelectric element 3.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to an electronic thermometer.

[Technical background of the invention and its problems]

The recent wave of electronic thermometers has also affected glass thermometers, and electronic thermometers are attracting attention because they are non-polluting, do not use mercury, have easy-to-read displays, and are difficult to damage.

A new function required for thermometers due to the Takako version is the function of notifying the elapse of the temperature measurement time or the end of temperature measurement, and the best method would be to notify by a buzzer.

However, in order to notify by a buzzer, a driving circuit is required. This circuit is two to three orders of magnitude larger than the current required for normal temperature measurement, so if this circuit is incorporated into a normal electronic thermometer LSI, the chip area will increase by several seconds, and the cost of the LSI will also be the same. This leads to an increase in the cost of the thermometer itself. Similar problems will also occur if an external driving transistor is added.

[Purpose of the invention]

It is an object of the present invention to eliminate the above-mentioned drawbacks and to provide an electronic thermometer having a function of generating a notification sound without increasing costs.

[Summary of the invention]

This invention is characterized in that the sensor that detects body temperature and the element that drives the buzzer are shared by one transistor.

〔Effect of the invention〕

According to this invention, it is possible to add a notification function to an electronic thermometer without adding a new transistor for driving a buzzer.

[Example of invention ¥'MfJ]

An embodiment of the present invention will be described in detail below with reference to the drawings.

The electronic thermometer according to the present invention includes a transistor Tr11 that detects temperature, an LSI 2 that converts the detected temperature into body temperature and drives a display, a piezoelectric sensor 3 that generates a report sound, and a piezoelectric sensor 3 that converts the detected temperature into body temperature and drives a display. It consists of a coil 4 that resonates, a display circuit 6 that displays body temperature, and a battery 5 that supplies power to the entire body.

Note that inside the LSI2, there are resistors R and z1 and a transistor Tr.
, 22. Control circuit 23. Temperature measurement circuit 24. Arithmetic circuit 252
It consists of a display drive circuit 26.

The operation will be explained below. The sequence control of this device is performed by the control circuit 23. First, the 11 sub-circuits 23
The collector and emitter of the transistors Tr and 23 are short-circuited by the output of , and the base collector of the transistor TrX1 is short-circuited, so that the transistor Trll enters temperature measurement. The principle of side temperature is based on the fact that the voltage across the PN junction of the pace emitter of the transistor Tr11 changes with temperature t. The temperature measurement circuit 24 amplifies the voltage corresponding to the temperature detected by the transistor Tr11.

The amplified voltage value is converted into body temperature by the arithmetic circuit 25 while being controlled by the control circuit 23. Next, display drive circuit 2
6 and is output to the display circuit 6 while being controlled by the control circuit 23, so that the body temperature is displayed on the display circuit 6.

Next, when the buzzer is used to notify, the control circuit 23 includes a control pulse to release the short-circuited state of the transistor Tr122, and this operation is intermittent. Then,
Energy is accumulated in the coil 4I, causing resonance with the piezoelectric sensor 3, and a buzzer sound is generated.

[Brief explanation of drawings]

The drawing is a block diagram showing one embodiment of the present invention. 1...Transistor, 2...LSI, 3...Piezoelectric vibrator, 4...Coil, 5...Battery, 6...Display circuit.

Claims (1)

[Claims] A means for detecting temperature, a means for converting a detection signal generated by the means into body temperature and displaying it, a means for generating a notification sound, and controlling switching of operations of the temperature detection means and the notification sound generation means. 1. An electronic thermometer comprising: means for detecting a temperature, the temperature detecting means driving a notification sound generating means.