JPS58103015A - Electronic apparatus having power generating function - Google Patents

Abstract

PURPOSE:To improve the functional performance of a portable electronic apparatus, by providing a means, which applies a mechanical displacement to a piezoelectric element, and a means, which accumulates the power induced from the piezoelectric element, to perform the operation of a prescribed function by the accumulated power. CONSTITUTION:A liquid crystal display type electronic calculator is provided with a piezoelectric element 2 where a piezoelectric ceramic plate is stuck to a metallic plate, and a mechanical deformation is given to the piezoelectric element 2 by a pressure applying means 1 due to one specified key switch out of operation key switches. An AC power induced from the piezoelectric element 2 by the operation of this pressure applying means is converted to a DC voltage by a rectifying circuit 3 and is accumulated in an accumulating circuit 4. An LCD51 and LSI52 of a function circuit 5 connected to a keyboard 53 are operated by this power accumulated in the accumulating circuit 4. Thus, a required operating power is obtained semipermanently by the piezoelectric element 2 having a simple structure to improve the functional performance of a portable electronic apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a portable electronic device with low power consumption, such as an electronic desktop calculator, which has a built-in piezoelectric element and has a power generation function that generates power as needed to obtain operating power.

In recent years, there has been a remarkable trend toward miniaturization and lower power consumption in portable electronic devices such as electronic desktop calculators (hereinafter referred to as calculators), and in particular, small calculators with liquid crystal displays consume only a few microwatts of power. Products have already been commercialized and sold.

By the way, it is preferable for such electronic devices to have a built-in small dry cell battery such as a mercury battery as their power supply source, and this is the ultimate in improving functionality and economic efficiency as a portable electronic device. was considered an issue. In other words, even if it is possible to extend the life of the dry cell battery by reducing power consumption as described above, the maintenance costs associated with battery replacement when using this electronic device for a long time cannot be ignored, and A minimum structure for replacing the dry batteries is also required. For this reason, electronic devices have been developed that try to eliminate these inconveniences by incorporating solar cells that do not need to be replaced (and can provide power semi-permanently).However, the solar cells mentioned above are relatively expensive. can be,
This is a factor that increases the product cost of the electronic device itself.

The present invention has been made in view of the above-mentioned circumstances, and by using a piezoelectric element that converts mechanical energy into electrical energy to obtain the desired operation, semi-permanent power supply can be achieved at a very low cost. The purpose of the present invention is to provide an electronic device that has a power generation function that can be realized.

(3) Hereinafter, an electronic device having a power generation function according to the present invention will be described in detail with reference to embodiments of the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of an electronic device having a power generation function according to the present invention.

In FIG. 1, a pressurizing device 1 applies mechanical deformation to a piezoelectric element 2 that is lowered through an appropriate mechanism such as a button or a lever exposed on the surface of the electronic device. Of course, the buttons, levers, etc. mentioned above are operated manually. The piezoelectric element 2 is made into a bimorph by pasting a piezoelectric ceramic thin plate onto a metal plate with excellent elasticity and conductivity, and corresponds to the direction and degree of deformation by applying mechanical deformation by the pressure device IK. generates AC power. The rectifier circuit 3 is, for example, a diode bridge circuit that rectifies the alternating current power generated by the piezoelectric element 2, and the power storage circuit 4 is, for example, a capacitor that sequentially stores this rectified power. The power stored in this power storage circuit 4 is given as operating power (A) to the functional circuit 5. Note that an appropriate voltage constant voltage circuit made of a Zener diode or the like may be interposed between the power storage circuit 4 and the functional circuit 5 to prevent the application of overvoltage to the functional circuit 5.

In this way, this electronic device transfers mechanical energy artificially applied via the pressurizing device 1 to the piezoelectric element 2 and the rectifier circuit 3.
The power storage circuit 4 converts the power into appropriate electrical energy to operate the functional circuit 5, making it possible to receive power semi-permanently without the need to replace any parts.

Therefore, this electronic device can be compared to an example of low power consumption tJ-
It is of great significance that it can be applied to liquid crystal display calculators, toy equipment using this, or electronic control circuits for cameras.

The specific structure and operation of the electronic device of the above-described embodiment when applied to a liquid crystal display type calculator will be explained below.

For liquid crystal display type calculators, the liquid crystal display element C (hereinafter referred to as LOD)
It is roughly composed of (4) a large-scale integrated circuit (hereinafter referred to as LSI), a keyboard, and some resistors and capacitors.

By the way, when considering the operating power of this liquid crystal display type calculator, the elements that actually consume power among the above components are limited to the LCD and LSI, and furthermore, the LCD is not a light emitting element but reflects and absorbs external light. Since this is a control display element and its current consumption is at most 1 microampere or less, it is probably the LSI that is the main power consumption source for this calculator.
It can be seen that this calculator can be operated if the LSI is limited to one voltage and current and can be supplied with an operating voltage and current. Here, the operating voltage of the current LSI, which is 0MO8, is 1.5 volts and the operating current is 6 microamperes, which are values that are sufficient to generate electricity using the piezoelectric element.

Now, FIGS. 2 and 3 show the example electronic device shown in FIG. 1 as a functional circuit with LOD51. It is a block diagram when applied to a liquid crystal display type calculator equipped with an LSI 52 and a keyboard 53, and FIG. 2 shows a case where special mechanisms such as buttons and levers are provided on the operation panel surface as the pressurizing device 1. FIG. 3 shows a case where the keyboard 53 is used as a pressure device to apply mechanical deformation to the piezoelectric element 2. Note that in FIGS. 2 and 3, the same devices or circuits as those shown in FIG. 11 are denoted by the same numbers, and redundant explanations will be omitted.

As shown in FIGS. 2 and 3, there are two possible applications for liquid crystal display type calculators, depending on the configuration of the pressurizing device.

For example, the application example shown in FIG. 2 is of a type in which the pressure device 1 is operated every time a calculation is attempted using the calculator to secure operating power. Therefore, how to maintain this secured operating power for a long time depends on the capacitance of the capacitor constituting the power storage circuit 4 and the functional circuit 5 (especially the LSI 5
Although it depends on the power consumption characteristics described in 2), if currently manufactured small-sized, large-capacity, high-density capacitors and low-power consumption LSIs are used, it is possible to maintain the time required to perform daily total IK. Note that when performing calculations continuously for a long time, L
The operation of the pressurizing device 1 may be repeated as appropriate while monitoring the brightness of the CD screen. In this way, the type shown in Figure 2 is generally sufficient, but when used continuously for a long time as mentioned above, the type shown in Figure 3 is more convenient. be. In other words, in the type shown in Fig. 3, if the operating power of the functional circuit 5 is generated only for the start of calculation by pressing any key switch appropriately, then each predetermined key is pressed for subsequent calculation execution. Since electricity is automatically generated and stored every time an operation is performed, there is no need to worry about power outages occurring during calculations.

The electrical configuration and its operation have been described above. Next, specific examples of assembly structures for these two application types will be described.

FIGS. 4(a) and 4(b) show an example of the assembled structure of the type shown in FIG.
A push button is used. Other components shown in the figure include a piezoelectric element 2 (7), a rectifier circuit 3, a capacitor 4 constituting a storage circuit, 51 an LCD, and 52 an LSI.

53 is a keyboard, C is a case of the calculator, P8 is a printed circuit board, AC is a piezoelectric element support case, and L is a lead wire of the piezoelectric element 2. In particular, the piezoelectric element 2 is attached to a piezoelectric element support case in order to improve the power generation efficiency. It is installed in the AC in a curved manner as shown in FIG. 2(b). Therefore, piezoelectric element 2
is deformed by the protruding bottle P every time the push button serving as the pressurizing device 1 is pressed, and generates electric power corresponding to the deformation. This generated power is extracted by the lead wire, and this extracted power is rectified,
As described above, the electricity is further stored and added to the LSI 52.

Although the shape of the piezoelectric element 2 is arbitrary, for example, a disc-shaped element as shown in FIG. 5 is used here. However, in FIG. 5, 21 is a metal plate with excellent elasticity and conductivity, and 22 is a piezoelectric ceramic thin plate.

Figures 6(a) and (b) are of the type shown in Figure 3.
8) It shows an example of the assembly structure of something.

These components include a piezoelectric element 2, a rectifier circuit 3, and a rectifier circuit 4.
is a capacitor constituting a power storage circuit, 51 is an LCD, 52
is the LSI, 53 is the keyboard, C is the case, FB is the printed circuit board, AB is the piezoelectric element support block, and L is the lead wire of the piezoelectric element 2. In particular, each key switch of the keyboard 53 has a protrusion as shown in the figure. A pin P is provided, and the structure is such that the piezoelectric element 2 is deformed each time each of these key switches is pressed. The power generated from the piezoelectric element 2 by suppressing the key switch is extracted by the lead wire as described above, further rectified, stored, and applied to the LSI 52. Here, it is assumed that the shape of the piezoelectric element 2 shown in FIG. 7 is used (as in FIG. 5, numeral 21 is a metal plate and 22 is a piezoelectric ceramic thin plate). This makes it possible to generate and store electricity in response to all key operations.

Note that the structures shown in FIGS. 4 and 6 are merely examples, and any other structure may be used as long as fundamentally equivalent functions can be obtained. For example, the piezoelectric elements may have a multilayer structure, and the electric power obtained from each unit element may be combined and stored. This has a significant effect in increasing the power generation effect of the piezoelectric element. Furthermore, by applying the structures shown in FIGS. 4 and 6, a relatively frequently used clear key, for example, can be selectively used as the pressurizing device 1.

Incidentally, although a detailed explanation will be omitted for the sake of convenience, when the electronic device according to the embodiment of the present invention shown in FIG. It would be convenient if it could be used for both purposes. That is, each time this lever is operated, the piezoelectric element 2 is deformed to generate and store the required power, and the electronic control circuit, which is the functional circuit 5, is operated based on the stored power. .

As explained above, according to the electronic device having a power generation function according to the present invention, the required operating power can be obtained semi-permanently using a very inexpensive element called a piezoelectric element, and it is highly functional and economical as a portable electronic device. performance can be significantly improved.

[Brief Description of the Drawings] Fig. 1 is a block diagram showing an embodiment of an electronic device having a power generation function according to the present invention, and Figs. 2 and 3 respectively show the embodiment shown in Fig. 1 on a liquid crystal display. FIGS. 4 to 7 are block diagrams in the case where the present invention is applied to a model calculator. FIGS. 4 to 7 are block diagrams showing specific structural examples of each of the calculators shown in the block diagrams in FIGS. 2 and 3. DESCRIPTION OF SYMBOLS 1... Pressure device, 2... Piezoelectric element, 3... Rectifier circuit, 4... Power storage circuit, 5... Functional circuit, 51...
LCD, 52... Ls engineering, 53... Keyboard. Combined Figure 4 (a) (b) B Figure 5 Figure 6 (C1) (b) Figure 7

Claims (5)

[Claims] (1) A piezoelectric element, a pressurizing means for applying mechanical deformation to the piezoelectric element, and an electricity storage means for storing electric power induced from the piezoelectric element, and the electric power stored in the electricity storage means is used. An electronic device having a power generation function, characterized in that it performs a predetermined functional operation. (2) The electronic device having a power generation function according to claim (1), wherein the electronic device is a liquid crystal display type electronic desktop calculator. (3) The pressurizing means has a power generation function as set forth in claim (2) that mechanically deforms the piezoelectric element in response to depression of a specific one of the calculation key switches. Electronics. (4) The pressurizing means corresponds to a plurality of calculation key switches, and mechanically deforms the piezoelectric element each time each of the plurality of calculation key switches is pressed. An electronic device having a power generation function as described in paragraph (2). (5) The electronic device having a power generation function according to claim (2), wherein the pressurizing means applies mechanical deformation to the piezoelectric element in response to operation of an appropriate mechanical component corresponding to a power switch.