JPH0322568B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a portable electronic thermometer.

[Prior art]

Recently, in the thermometer market, electronic thermometers that digitally display temperature results have been seen here and there among mercury thermometers. However, this type of electronic thermometer has a complicated structure, so it is much larger and more expensive than a mercury thermometer.

That is, the conventional electronic thermometer has a structure in which the main body case is divided into two parts, and the two parts are combined with a fine screw used to make the product smaller, which makes assembly difficult. In addition, since the power switch uses a slide switch, it has many mechanical parts such as leaf springs and springs, making the structure complicated, making it difficult to assemble, and occupying a large amount of space. These 2
Two reasons are making products larger and increasing manufacturing costs.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems of the prior art, and its purpose is to provide an electronic thermometer that is easy to assemble, is compact, and is inexpensive.

[Summary of the invention]

In order to achieve the above object, the present invention includes a longitudinal main body case, a temperature sensing section provided at the front end of the main body case, a temperature measuring circuit section including a circuit board, a body temperature measurement value display, a power supply section, and a power switch. In the equipped electronic thermometer, open the rear end of the main body case, and
The front part of the inner wall of the main body case is formed narrow, the circuit board is inserted from the open rear end side of the main case, and a part of the front part of the circuit board is held between the grooves of the inner wall of the main case.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on the drawings. 1 is an external front view of an electronic thermometer according to an embodiment of the present invention, FIG. 2 is a front sectional view of the electronic thermometer shown in FIG. 1, and FIG. 3 is a plan sectional view of the electronic thermometer shown in FIG. 1.

In Fig. 1, 2 is a long and flat plastic main body case, and 1 is a main body case 2.
A temperature-sensing section is provided at the front end of the body and consists of a thermistor and an aluminum cap to protect it; 6 is a display that displays the measured body temperature value using a liquid crystal; 9 is a power switch that is operated at the start of temperature measurement. The tip of the main body case 2 to which the temperature sensing part 1 is attached has an outer diameter of approximately 4~
It forms a 5mm hollow shaft. Further, the front surface of the main body case 2 has an opening for providing a display 6 and a power switch 9, and the back surface has an opening for circuit adjustment provided inside the main body case 2, as will be described later. , an opening for a battery case is opened at the rear end (9c will be described later).

In Figures 2 and 3, 3 is a circuit board made of an elastic glass cloth-based epoxy resin plate with a thickness of 0.6 mm, and 8a to 8f are external circuit components soldered to the back side of the circuit board 3. , 8f is a trimmer for adjusting the circuit, and 5 is a temperature measuring IC that intermittently samples the temperature of the temperature sensing section 1 and displays it on the display 6 (FIG. 3). This IC 5 is a chip that is wire-bonded directly to the circuit board 3 and sealed, and its interior is manufactured using a low power consumption C-MOS process. In addition, the driving voltage of IC5 is
1.5V, the switch signal generated by operating the power switch 9 enters the temperature measurement mode, and after maintaining the temperature measurement mode according to predetermined conditions, the display 6 is turned off and the measurement standby state occurs. Since these are not directly related to the present invention, they will be omitted.
The temperature measuring circuit section 19 is constituted by the upper parts, that is, the circuit board 3, the external circuit parts 8a to 8f, and the IC 5.

4 is provided on the front inner wall of the main body case 2,
These ribs form grooves for holding the circuit board 3. Note that the ribs 4 are not held over the entire length of the circuit board 3, but are provided up to point A as shown in the figure, and hold approximately half of the front half of the circuit board 3. In addition, the main body case 2 to which the circuit board 3 is attached
The inner diameter dimension W is not constant over the entire length of the circuit board 3, but increases from the front toward the rear end, thereby forming a narrower width at the front. Therefore, when the circuit board 3 is inserted from the open rear end side of the main body case 2, the ribs 4 formed on the inner wall of the main body case 2
The ribs 4 restrict movement in the direction perpendicular to the surface, but the inner diameter W of the main body case 2 is larger than the width of the circuit board 3. If force is applied, the circuit board 3 can be displaced in a direction perpendicular to its surface within the elastic limit range of the circuit board 3.

The power switch 9 of the present invention is a push button switch, and in this embodiment, as shown in the figure, it is made of insulating rubber 9a and conductive rubber 9b.
It is fixed to the circuit board 3. This is not limited to the one in this embodiment, and may be any push button switch that sends out a signal when pressed.
The pressing surface of the power switch 9 is almost the same as the surface of the main body case 2, and the pressing surface protrudes slightly outward. Also, 9c (Figure 1)
is an opening inclined surface on the outer periphery of the opening provided in the main body case 2 for the power switch 9.

A display holder 7 fixes the display 6 to the circuit board 3.

10 is a battery for power supply, for example, a silver oxide battery, 1
1 is a battery case detachably provided at the rear end of the main body case 2; 11a is a tongue part integrally provided at the end of the battery case 11 and inserted into the main body case 2; 12 is a tongue part provided under the battery case 11; Further, a terminal 14 corresponds to the negative pole of the battery 10, and a terminal 14 corresponds to the positive pole of the battery 10, which is attached to the circuit board 3. These parts constitute a power supply section 20.

Note that the thickness B of the tongue portion 11a is equal to the distance between the back surface of the circuit board 3 held by the ribs 4 of the main body case 2 when it is not elastically deformed and the inner wall of the main body case 2 facing thereto. As a result, when the power switch 9 is pushed in the direction of arrow C, the pressing force is applied to the tongue portion 11 without causing deformation of the circuit board 3.
a is starting to accept it himself.

12a (Fig. 3) is a convex portion provided integrally with the terminal 12 near the tongue portion 11a of the terminal 12;
It sticks out a little more than that. Reference numeral 13 denotes a hole provided at the rear end of the circuit board 3, which engages with the convex portion 12a.

In FIG. 3, reference numeral 15 denotes a back cover that covers an opening provided on the back side of the main body case 2, that is, on the side opposite to the display 6, in order to adjust each part of the temperature measurement circuit section 19;
are locking claws integrally provided at both ends of the back cover 15, which are inserted into and engaged with the main body case 2. Reference numeral 17 indicates a boss for positioning the circuit board 3, which is integrally provided inside the back cover 15, and reference numeral 18 indicates a hole provided in the circuit board 3 that engages with the boss 17.

Next, the assembly order of the electronic thermometer of this embodiment configured as described above will be explained.

First, insert the lead wire of the temperature sensing part 1, which is made by putting a thermistor into an aluminum cap and fixing it with silicone adhesive, into the hollow shaft at the tip of the main body case 2. Glue and fix. Next, external circuit components 8a to 8f are attached to the back side of the circuit board 3 to which the IC 5 is wire-bonded.
After soldering the positive terminal 14, a liquid crystal display 6 is attached to the surface of the circuit board 3 via a display holder 7, and a power switch 9 is further bonded. The above component-mounted circuit board 3 is inserted into the main body case 2 through the opening of the battery case 11 at the rear end of the main body case 2. At this time, as described above, only the front side of the circuit board 3 is held by the ribs 4, so the power switch 9 is placed on the circuit board.
Even if the power switch 9 sticks out and is fixed, the power switch 9
until the convex part enters the corresponding opening of the main body case 2.
The elastic circuit board 3 can be bent and mounted in a predetermined position.

Next, a soldering iron is inserted through the circuit adjustment opening covered by the back cover 15 of the main body case 2, and the lead wires of the temperature sensing section 1 are connected to the corresponding locations on the circuit board 3.

Next, put the negative terminal 12 under the battery case 11, and use the soldering iron to
A part of the terminal 12 is thermally deformed to fix the terminal 12 so that it does not fall off.

Furthermore, a battery case 1 containing a silver oxide battery 10
1 into the opening at the rear end of the main body case 2. Here, after the convex part 12a of the terminal 12 provided on this battery case 11 pushes up the circuit board 3, it enters the hole 13 of the circuit board 3, so that the user who is replacing the battery is forced to "snap". This provides a click feeling to confirm that the battery case 11 has been installed in a predetermined position.

Thereafter, the temperature sensing part 1 attached to the main body case 2 is placed in a constant temperature water bath for adjustment, and the adjustment trimmer 8c is inserted from the opening on the back of the main body case 2 so that the displayed value on the display 6 becomes the predetermined temperature. adjust.

Next, after verifying the measurement accuracy of the product, when the back cover 15 is pushed into the back opening of the main body case 2, the positioning boss 17 inside the back cover 15 aligns with the hole 1 of the circuit board 3.
8 to determine the position, and the back cover 15
The claws 16 at both ends engage with the main body case, and the back cover 15
is attached, and the assembly of the electronic thermometer is completed.

Next, the operation of the electronic thermometer of this embodiment when used will be explained.

That is, when the user uses this electronic thermometer to measure the temperature, first press down the power switch 9 so that the finger touches the opening slope 9c of the main body case 2, and the circuit board 3 will be moved by the pressed conductive rubber 9b. Although the circuit board 3 is subjected to a downward force, since the force is supported by the tongue portion 11a of the battery case 11 as described above, the circuit board 3 is not deformed in a direction perpendicular to its surface and is therefore not damaged.

In addition, by using this electronic thermometer,
When replacing the battery 10 because the battery 10 has been exhausted and its voltage has decreased, the battery case 11 is pulled out from the main body case 2 rearward and a new battery 10 is installed there. Here, when pulling out the battery case 11, the circuit board 3 is connected to the negative terminal 12.
Due to the engagement between the protrusion 12a and the hole 13, the battery case 11 is pulled out to the rear along with the battery case 11.
Back cover 15 fixed to main body case 2 with claws 16
Since the boss 17 of the circuit board 3 is fitted into the hole 18 of the circuit board 3, the circuit board 3 does not move, so that the lead wire connected to the temperature sensing part 1 is stretched and disconnected. The power switch 9 is prevented from being mechanically damaged.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the main body case has a longitudinal shape, a temperature sensing section provided at the front end of the main body case, a temperature sensing circuit section including a circuit board, a body temperature measurement value display, a power supply section, and In an electronic thermometer equipped with a power switch, the rear end of the main body case is open, the front of the inner wall of the main body case is made narrow, the circuit board is inserted from the open rear end of the main case, and the circuit board is Since the front part is held in the groove on the inner wall of the main body case, the circuit board can be installed by simply inserting it from the open rear end of the main case and guiding it. Moreover, since the front end is narrow, the circuit board or Even if the width of the inner wall of the main body case varies, this variation can be absorbed and assembly can be performed without using screws. Therefore, it is possible to provide a small, inexpensive electronic thermometer that is easy to assemble.

[Brief explanation of the drawing]

1 is an external front view of an electronic thermometer according to an embodiment of the present invention, FIG. 2 is a front sectional view of the electronic thermometer shown in FIG. 1, and FIG. 3 is a plan sectional view of the electronic thermometer shown in FIG. 1. 1...Temperature sensing part, 2...Main case, 3...Circuit board, 4...Rib, 6...Display unit, 9...Power switch, 10...Battery, 11...Battery case, 1
1a...Tongue, 12a...Protrusion, 13, 18...
Hole, 15...Back cover, 17...Boss, 19...Temperature measurement circuit section, 20...Power supply section.

Claims (1)

[Claims] 1. In an electronic thermometer that is equipped with a longitudinal body case, a temperature-sensing section provided at the front end of the body case, a temperature-measuring circuit section including a circuit board, a body temperature measurement value display, a power supply section, and a power switch, the rear end of the body case is opened, and the front part of the inner wall of the main body case is made narrow, the circuit board is inserted from the open rear end of the main case, and a part of the front part of the circuit board is held between the grooves of the inner wall of the main case. An electronic thermometer characterized by: