JPS6249596B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of an electronic wristwatch with a built-in speaker.

Conventionally, the sounding body of so-called alarm clocks, which are equipped with electronic wristwatches that produce sound, has been of the piezoelectric type, in which a piezoelectric element is bonded to a diaphragm, windshield, or back cover, or of the electromagnetic type, in which an electromagnetic buzzer is used. The sounding body vibrates at a frequency of several KHz, mainly 2KHz or 4KHz as an alarm sound,
Only sounds at specific frequencies resonated.

On the other hand, the development of the electronics industry has made it possible to output audio using ICs in recent years. From this, it is easy to think of a wristwatch with audio, but the sounding body used as the electro-acoustic converter in this case needs a sounding body that corresponds to the frequency band of the voice, and the piezoelectric type and electromagnetic type mentioned above are not suitable. It was impossible. Therefore, we use a speaker that corresponds to the audio frequency band as a sounding body, but the power required to drive even the ultra-compact speaker of a wristwatch is several tens of milliwatts.
This means that a current several times as large as that of the piezoelectric and electromagnetic types used for alarms will flow. Therefore, in a power supply used in a limited space such as a wristwatch, the power supply voltage may drop, and when the speaker is turned on, the main function of the clock may stop.

Furthermore, it is necessary for wristwatches to have a waterproof structure due to the environment in which they are used, and the same applies to electronic wristwatches that use speakers. This means that the speaker sounds in a tiny closed space called a wristwatch, but compared to the piezoelectric and electromagnetic sounding bodies used in alarm clocks, the speaker is much more susceptible to the effects of the closed space (hereinafter referred to as the back pressure chamber). The lowest resonant frequency of the speaker changes depending on this condition. The lowest resonant frequency increases as the back pressure chamber becomes smaller, and it no longer matches the audio frequency band, making it difficult to obtain an effective audio output. On the other hand, enlarging the back pressure chamber means enlarging the shape of the watch, which has the disadvantage of going against the need for smaller and thinner wristwatches.

The present invention solves the above-mentioned drawbacks, and provides a wristwatch with a speaker that can obtain the necessary audio output, prevent the clock function from stopping, and be made smaller and thinner.

The present invention will be explained below based on the drawings.

1A and 1B are plan views of a liquid crystal display wristwatch with a speaker according to the present invention, viewed from the display section side, and FIG. 1B shows a state in which a cover member for protecting the speaker, which will be described later, is removed.

In FIG. 1A, 1 is a watch case, 2 is a time display section made of liquid crystal, 3 is a cover member that has a mesh sound emitting hole and protects a speaker, which will be described later, and 4 is a screw that connects the four corners of the cover member 3. It is screwed onto case 1. Reference numerals 5 to 8 indicate switch buttons for performing operations such as correcting the time display section 2, changing display contents, and turning on a lamp (not shown). In Figure B with the cover member 3 removed, 9 is a speaker, and 10 is a cone constituting the speaker 9.
It vibrates and produces sound based on the signal from the IC.

Figure 2 is a sectional view taken along the line E--E in Figure 1, and shows the cone 10.
The outer periphery of the frame 11 is bonded to a frame 11 which is a supporting member made of metal or the like. A ring-shaped voice coil 12 is also bonded to the cone 10. On the other hand, the frame 11 has a permanent magnet 13 that constitutes a magnetic circuit.
Two yokes 14 are fixed between them.

The speaker 9 is fixed by fixing a ring-shaped support member 15 with a screw on the outer periphery to the threaded portion 1a of the watch case 1, thereby compressing a gasket 16 provided between the watch case 1 and the cone 10. It has a waterproof structure.

On the other hand, 17 is a circuit board which is a watch board, and an IC 18 is mounted on the opposite side from the speaker 9, and electronic components such as a crystal oscillator 19 are soldered.
20 is a circuit support stand made of synthetic resin, and the IC
It has the role of protecting the electronic components on the circuit board 17, such as 18 and crystal resonator 19, as well as supporting the silver batteries and lithium batteries shown at 21 and 22.
23 is made of a metal plate with a switch button 5 at the tip.
8, a switch plate 24 is a module cover member to which a tube 25 indicated by a broken line is fixed;
Circuit board 17, circuit support stand 20, switch board 23
The tube 25 is passed through a predetermined hole (not shown) and fixed with a screw 26. In addition, 27,2
8 is a battery receiving spring for the silver battery 21 and the lithium battery 22; 29 is a battery press spring for fixing the silver battery 21 and the lithium battery 22, and is fixed to the tube 25 with a screw 30. The battery receiving springs 27, 28 and the battery pressing spring 29 are in contact with the circuit board 17 to supply power.

Note that the time display section 2 includes a liquid crystal cell 3 that constitutes the time display section 2.
1 is held by a liquid crystal support frame 32 made of synthetic resin. Reference numeral 33 is a conductive rubber that establishes conduction between the circuit board 17 and the electrode pattern (not shown) of the liquid crystal cell 31. 34 is a light guide plate that diffuses the light from a lamp (not shown) over the entire surface of the liquid crystal cell, and 35 is a reflection plate.
The liquid crystal cell support frame 32 is fixed to the tube 25 of the module cover member 24 by screwing. (See Figure 3A) 36 is two coil springs, each connected to a terminal (not shown) of the lead wires 12a, 12b of the voice coil 12 and a pattern (not shown) on the circuit board 17.
There is continuity between the two. 37 is a coil spring support member made of synthetic resin, and a dowel 37a that passes through a hole in the circuit board 17 is deformed by heat and fixed to the circuit board 17.

FIG. 3 is a plan view of the timepiece module of this embodiment in FIG. 1, where A is a plan view seen from the time display section 2 side, and B is a plan view seen from the back cover side.

In Figure B, electronic components provided on the circuit board 17 are indicated by broken lines. IC18 is a watch IC
18a, an audio IC 18b, and a current amplification IC 18c that performs current amplification for driving the speaker. are combined. 38 is an oscillation capacitor, 3
9 is a trimmer capacitor, which together with the crystal resonator 19 constitutes an oscillation circuit. 40 is a power supply capacitor which is generated when the silver battery 21, which is the power source of the watch IC 18a, and the battery receiving spring 27 or the battery pressing spring 29 are momentarily separated from each other.
This is to prevent malfunction of a. 41 is a step-up capacitor that boosts the voltage of the silver battery 21 to the voltage necessary for displaying the time display section 2 using two capacitors;
2 is an alarm capacitor, 43 is an audio resistor,
Reference numeral 44 denotes an audio capacitor, each of which is soldered to the circuit board 17.

As explained above, in the electronic wristwatch with a speaker of the present invention, the speaker and the time display section are arranged in a plane on one side via a watch circuit board, and the silver battery and the lithium battery are arranged in a shifted manner in a plane on the other side. Moreover, it is a configuration in which electronic components such as ICs, crystal oscillators, and capacitors are placed in the space formed between the lithium battery and the circuit board due to the difference in thickness between the silver battery and the lithium battery. As a result, in the wristwatch of the present invention, which has electronic components necessary for audio reproduction in addition to the electronic components necessary for the watch, most of the electronic components can be placed on one side of the circuit board by utilizing the space under the lithium battery. Therefore, the space behind the speaker, that is, the capacity of the back pressure chamber, can be maximized. Therefore, it is possible to prevent the lowest resonant frequency of the ultra-small speaker incorporated into the wristwatch from becoming as high as possible, and to achieve matching with audio. Furthermore, according to the above configuration, by using a coin-shaped lithium battery that is thinner than a button-shaped silver battery, the cross-sectional positions of the silver battery and the lithium battery are almost the same, that is, the silver battery part and the lithium battery part in the watch module are Since the thickness can be made the same, watches can be made smaller and thinner.

On the other hand, as mentioned above, the present invention has two power sources: a silver battery and a lithium battery.The silver battery is used as a power source for clock circuits, and the lithium battery is used as a power source for driving speakers, lighting lamps, etc. that require large currents. For,
Even if the power supply voltage drops due to speaker drive, the clock circuit operates normally. In addition, the lithium battery has a voltage of about 3V, which is about twice the voltage of a silver battery, which is 1.5V, so that the necessary output for driving the speaker can be easily obtained. If this were to be done with silver batteries, it would be necessary to use two batteries in series, and if two silver batteries were used instead of one lithium battery due to the structure of the watch, there would be disadvantages of placement or an increase in battery support springs. Moreover, as the number of batteries increases, the assembly workability etc. deteriorates, so it is very effective to perform this with a single lithium battery. Furthermore, lithium batteries have a larger capacity than silver batteries, and can be used for a long time when driving a speaker, which consumes a large current compared to that of a clock circuit, making it a very practical means.

[Brief explanation of the drawing]

1A and 1B are plan views of a speaker-equipped wristwatch according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line A in FIG. 1A, and FIGS. FIG. 2...Time display section, 9...Speaker, 17...
Circuit board, 18...IC, 21...Silver battery, 22
……Lithium battery.

Claims (1)

[Claims] 1. In an electronic wristwatch that includes a watch board, a watch IC, an audio IC, a time display, and a speaker, the time display and the speaker are arranged on one side of the watch board, and the time display and the speaker are arranged on the other side of the watch board. is a button-shaped silver battery that is a power source for driving the clock IC and audio IC, and a coin-shaped lithium battery that is thinner than the silver battery and is a power source for driving the speaker. and electronic components such as the clock IC and the audio IC are arranged in a space formed by the difference in thickness between the silver battery and the lithium battery. electronic watch.