JPS6121561A - Electronic desk top calculator - Google Patents

Abstract

PURPOSE:To prevent a solar battery from generating a voltage to some degree or over by forming a specific segment to a part of a liquid crystal display device so as to cover a part or all of the solar battery, and controlling it with a voltage equal to a drive voltage. CONSTITUTION:The solar battery 22' is placed while being overlapped under the liquid crystal display device 21' and the specific segment pattern 30 of the liquid crystal display device 21' covers the entire face of the solar battery 22'. Since it is required to transmit light through the solar battery 22', the specific segment pattern 30 is not provided with a reflection plate but it is formed as transmission type. Through the constitution above, when the illuminance of the solar battery 22'is high and the voltage produced from the result approaches an upper limit voltage in the operating voltage range, the specific segment 30 formed to cover the solar battery is controlled by a voltage equal to a liquid crystal display drive voltage to reduce the transmitivity. Thus, the overvoltage generation of the solar battery is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention shows an example of a circuit of an electronic machine that operates using a solar cell as a power source.

1 is a solar cell used as a power source, 2 is a solar cell 1
3 is a light emitting diode that suppresses the voltage generated by the solar cell 10 so that a voltage higher than a certain level is not generated when the illuminance of the light received by the solar cell 1 becomes low; 3 is a capacitor that charges the electricity generated by the solar cell 1; 4 is a capacitor for charging the electricity generated by the solar cell 1; LS that executes the calculator function
I, 5 is an oscillation resistor for generating a clock signal for the operation of LSI 4, 6 is a capacitor for approximately doubling the voltage supplied from solar cell 1 for the Id liquid crystal display drive, and 7 is a display. 8 is a group of keys.

When the solar cell 1 receives light, a potential difference is generated between the positive and negative electrodes of the solar cell 1, and the glass electrode of the solar cell 1 is connected to the glass power terminal of the LSI 4, and the minus and negative electrodes of the solar cell 1 are connected. By connecting the solar cell 1 to the negative power terminal of the LSI 4, the voltage generated by the solar cell 1, which is used as a power source for the LSI 4, is approximately doubled in the LSI 4, and the voltage value is doubled to drive the liquid crystal display device 7. Use as voltage. General trap: When the illuminance of the light received by solar cell 1 increases, the potential difference between the glass electrode and the negative electrode increases under a constant current load.0Solar cell 1
If the generated voltage is too high, the brightness of the non-lit segments of the liquid crystal display will decrease, and the contrast ratio with the lit segments will decrease.

It becomes impossible to distinguish between lighting and non-lighting. Therefore, when the illuminance of the light received by the solar cell 1 is too high, current is consumed in the light emitting diode 2 to suppress the voltage generated by the solar cell.

By charging the electricity generated by the solar cell 1, the capacitor 3 reduces the power supply voltage of the LSI 4 in response to temporary changes in the illuminance of the light received by the solar cell 1 and temporary changes in the current consumption in the LSI 4. It has the role of keeping fluctuations small.

FIG. 2 shows a block diagram of the liquid crystal display circuit related parts of the LSI 4.

9 is a voltage doubler generation circuit section, 10 is a timing generation circuit section,
11 is a common signal generation circuit section, 12 is a display RAM, 1
3 is a segment signal generation circuit section.

In the zero times voltage generation circuit section 9, the positive power supply voltage of the LSI 4 is represented by GND, and the negative power supply voltage is represented by VDD, a voltage 2·VDD8, which is approximately twice VDD, is generated.

The output signal voltage level of the common signal generation circuit section 11 is appropriately selected from GND, VDD, and 2''vDD, and the output signal voltage level of the segment signal generation circuit section 13 is appropriately selected from GND, 2.VDD.

The W1 level selection signal of the common signal generation circuit section 11 is supplied from the timing generation circuit section 10, and the output level selection signal of the segment signal generation circuit section 13 is supplied from the timing generation circuit section 10 and the display RAM 12.

FIG. 3 shows a circuit example of a C0M10 generating section, which is one of the common signals, in the common signal generating circuit section 11,
FIG. 4 shows a circuit example of a generation section of 5EG1, which is one of the segment signals, in the segment signal generation circuit section 13. In FIG. 3, 14 to 17 are transfer gates, 18 is an inverter, and transfer gate 14
and 17 are ON when the COMI original signal is high level and OFF when it is low level,) Lance 7 arc) 15 and 1
6 is OFF when the COMI original signal is /S high level, ONL when it is low level, 00M1 signal output voltage level is 00M
1 When the original signal is low level, VDD high level. When the OMI original signal is no-low level and the frame signal is high level, 2-VDD level is output. When the 00M1 original signal is high level and the frame signal is low level, GND level is output.

In Figure 4, the 19u circuit 7 0J20 is an inverter, and the 5EGI signal output voltage level is indicated by AM.
(8EG1-COMI) When the signal and frame signal are both high level or both low level, GND level, display RA
When either the M (8EG1-COMl) signal or the frame signal is a no-y level, the other is a low level, 2-VDD
The level signal is output.

Figure 5 shows the 00M1 original signal, frame signal, and display RAM (SEGl-COM't) when the liquid crystal display is at 1/3 duty.
5E when the signal, COMI output signal and 5EGI are all lit
FIG. 6, which shows an example of a GI output signal output waveform, shows an example of a liquid crystal display button of a conventional solar battery-powered electronic desk calculator.

FIG. 7 shows an example of the external appearance of a conventional solar-powered electronic desktop calculator. 21 is a liquid crystal display device, 22 is a solar cell, and the liquid crystal display device #, 21 and the solar cell 22t;j: are set separately without overlapping O (problem to be solved by the invention) as described above. As with the conventional solar powered desktop calculator, it was necessary to incorporate, for example, a light emitting diode as an element to limit the current load above a certain voltage value in order to limit the voltage. The purpose of this is to eliminate the need for a light emitting diode as the voltage limiting element, and simply provide a specific segment on the liquid crystal display device used as the display element, and through this specific segment, the portion of this specific segment is displayed on the liquid crystal display. If the solar cell is of a transmission type and is installed so that light can pass through part or the entire surface of the solar cell, the illuminance of the light received by the solar cell may be too high and the voltage supplied to the LSI may be too high. In this case, the light transmittance of a specific segment is set to automatically decrease, which has the effect of suppressing the voltage generated by the solar cell to a certain level.

(Means for Solving the Problems) The electronic desktop calculator of the present invention uses a solar battery as a driving power source and 1 to 1, and performs liquid crystal display using a voltage approximately twice the voltage of the driving power source. The device is formed so as to cover a part or the entire surface of the solar cell, and a specific segment is formed in a part of the liquid crystal display device so as to cover a part or the entire surface of the solar cell. H, l: It is characterized in that it is controlled to trap a voltage value equal to the voltage of the driving power supply. 0 (Embodiment) An embodiment of the present invention will be explained using FIG.
The figure shows an example of a circuit of an electronic desktop subtraction machine driven by a large scale pond according to an embodiment of the present invention. 1 is a solar cell used as a power source, 3 is a capacitor that charges the electricity generated by the solar cell 1, 4° is an LSI that performs the electric power function, and 5 is an LSI 4
An oscillation resistor for generating a clock signal for the operation of °, 6 a capacitor for approximately doubling the voltage supplied from the solar cell 1 to drive the LCD display, 7° for display and a liquid crystal display device for masking solar cells; 8 is a group of keys;

When solar cell 1 receives light, a potential difference is generated between the glass @J and negative electrical connections of solar cell 1, and the glass IF pole of solar cell 1 is connected to the glass power terminal of LSI 4°, and the negative By connecting the electrode to the negative power terminal of LSI 4°, solar cell 1 is used as a power source for LSI 4. Capacitor 3 charges the electricity generated by Taizan battery 1, and connects the solar cell to the negative power terminal of LSI 4°. It has the role of suppressing fluctuations in the power supply voltage of LSI 4° to a small extent with respect to temporary changes in the illuminance of light received by 1 and temporary changes in current consumption in LSI 4°.

Figure 9 shows a professional diagram of the liquid crystal display circuit related parts of LSI 4°. 023 is supplied from solar cell 1 [IEGND
-VnD17'! Resistor divider circuit for obtaining resistor 24/25 K-connection MLVDff voltage, 9 is voltage doubler generation circuit section, 10 is timing generation circuit section, 11 is common signal generation circuit section, 1
2 is a display RAlvi, 13 is a segment (Th number generation time, 16 parts, 26 is a % constant segment, segment drive signal generation circuit part).

The voltage doubler generating circuit section 9, the timing generating circuit section 10, the common signal generating circuit section 11, the display box AM12, and the segment signal generating circuit section 13 are the same as the conventional ones, and their explanations will be omitted.

The output signal level of the specific segment drive signal generation circuit section 26 is VD obtained from GND and the main shaft dividing circuit 23.
D', and the λ selection signal is the timing generation IgI
k! ! Supplied in 10 copies.

FIG. 10 shows an example of the circuit of the specific safety drive circuit section 26. 27 is an inverter which sets VDD to minus 'r4ys■ to glass 1fA, and 28 and 29 are VDD'
With an inverter that uses the negative power supply GND as the class power supply, when the frame signal is high-repe l+, UNI is applied to coux.
) Level b E G X iCV p O” Level,
When the frame signal is low level COM X K V D
D' level 8EGXICGND level is output.

Figure 11 shows the liquid crystal display 4 - the old signal C0Pv+1, which is a power 1/3 tutee, the signal L/-MUIZA, and the display RA81 (ljEGt-COM 1) signal (
1. SP when the output signal and 5EGI are all lit; 01 output signal, CO X output signal for specific segment drive, and 8EG Tai 1 by example of invention;
Liquid crystal display pattern of Kasumiike-driven electronic desk calculator f・“:
Indicate the size.

30 is a specific segment pattern driven by the C0fViX output signal and the 5EGX output signal.

Fig. 13 shows the external appearance of a solar cell 5° movement calculator according to an embodiment of the present invention; At the same time, a liquid crystal display device !121° specific segment pattern 30 covers the entire surface of the solar cell 22′.

FIG. 14 shows a cross-sectional view of the liquid crystal display device and the solar pond installed. 31rJ: *j upper light plate of crystal display device C, 32
id: the main body of the liquid crystal display device; 33, the lower polarizing plate of the liquid crystal display device; 34, the anti-Nvi of the crystallographic display; 35, the solar cell; Since it is necessary to transmit light to the solar cell 35, the specific segment button 30 is not provided with a reflective plate 34 and is of a transmission type.

The φ operation and effects of this embodiment will be explained below.

FIG. 15 is a graph showing the luminance of segments of a liquid crystal display device. The vertical axis is the brightness of the liquid crystal segment, and the horizontal axis is the potential difference value between the common segments'. Characteristic a is 1/
This is the selected waveform characteristic when the duty is 3 and the bias voltage is 1/2, and the characteristic is the non-selected waveform characteristic when the duty is 1/3 and the bias voltage is 172. Characteristic C is the characteristic when static drive is performed. are the selected waveform characteristics. In general, the voltage range where there is no crosstalk in the LCD display and there is no problem in actual use is V.
It is said to be between 2 and v3.

In order to effectively utilize the present invention, the 2 VDD voltage value must be
When the brightness of the specific segment 30 approaches , the brightness of the specific segment 30 should start to decrease. and resistor divider circuit 2 in Figure 9.
In the resistance value ratio x:y of the resistor 24 and the resistor 25 shown in FIG. 3, it is sufficient to determine the ratio x:y such that the following relational expression is satisfied.

V3'''2''VDD ■DDI: vl''vDDxv Takumi (Effect of the invention) As described above, the illuminance received by the solar cells increases, and 2.
When the voltage value of vDD approaches v3, it is formed so as to cover part or the entire surface of the solar cell and GND11vD
By reducing the brightness of a specific segment that is selectively driven at the D0 voltage, the light transmittance onto the solar cell is reduced, and it is possible to prevent a voltage exceeding a certain level from being generated in the solar cell.

[Brief explanation of drawings]

Figure 1 is a circuit diagram showing an example of a conventional solar battery-powered electronic desktop calculator, and Figure 2 is an example of an LSI liquid crystal display circuit-related portion used in a conventional solar battery-powered electronic desktop calculator. Figure 3 shows C in the common signal generation circuit section.
A circuit diagram showing an example of the OMI signal generation section, FIG. 4 is a circuit diagram showing an example of the 5EGI signal generation section of the segment code generation circuit section, and FIG. 5 is a circuit diagram showing an example of the COMI signal generation section.
A waveform diagram showing an example of the frame signal self-display RAM (8EG1-COMI) signal, 00M1 output signal, and 5EGI output signal. Figure 6 is a diagram showing an example of the liquid crystal display pattern of a conventional solar battery-driven electronic on-board calculator. , FIG. 7 is a diagram showing an example of the appearance of a conventional solar battery-driven electronic desktop calculator. FIG. 8 is a circuit diagram showing an example of a solar battery-powered electronic desktop calculator according to an embodiment of the present invention, and FIG. 9 is an LSI liquid crystal display circuit that can be used in the solar battery-powered electronic desktop calculator according to this embodiment. FIG. 10 is a block diagram showing an example of related parts; FIG. 10 is a circuit diagram showing an example of a specific segment drive circuit;
Figure 1 shows 00M1 original signal/frame signal and displays R, AM (
8EG1-COMI) signal-COMI output signal, 5E
COMX for G1 output signal and specific segment drive
Waveform diagram showing output signal and 5EGX output signal output example, 12th
The figure shows an example of the liquid crystal display button of a solar battery-driven ζ-hole senior calculator of this embodiment, and FIG. 13 shows an example of the external appearance of a solar-powered electronic 81-year-old calculator of this embodiment. Figure, 14th
The figure is a screen view of the liquid crystal display device and the solar cell installed in the solar battery-powered electronic table top according to this embodiment, and FIG. 15 is a graph showing the relationship between the segments of the liquid crystal display device. 0 1...Solar cell, 2...Light-emitting diode, 3...Content, 4...--L for electric power
8I, 5... Resistor for oscillation, 6... Capacitor for voltage doubler generation, 7... Liquid crystal display device, 8...
...Key group, 9...Double pressure brother production circuit section,
10... Timing generation circuit section, 11...
...Common signal generation circuit section, 12...Display 1
(, AM. 13...Segment signal generation circuit section, 14-1
7 ”...Transfer gate, 18...
... Inverter, 19 ... Exclusive 0, 20 ... Inverter, 21 ... Liquid crystal display device, 22 ... Solar 1iL pond, 23 ...・
...Resistance divider circuit, 24-25...Resistance,
26...Specific segment drive, signal generation circuit section, 27-29...Inverter, 30...
...Specific segment button, 31... Upper polarizing plate of liquid crystal display device. 32... Body of liquid crystal display device, 33...
・Lower polarizing plate of liquid crystal display device, 34...Reflector plate of liquid crystal display device. 35...Solar cell. 2nd drawing early 3rd time 4th kindergarten S drawing 6 drawing early 8 drawing 74 drawing 34 Yuga Ward Dan

Claims (1)

[Claims] In an electronic desk calculator that uses a solar cell as a driving power source and displays a liquid crystal display by boosting the driving power voltage, the liquid crystal display device is formed to cover a part or the entire surface of the solar cell, and the liquid crystal display device An electronic desk calculator characterized in that a part or the entire surface of a solar cell is formed under a specific display segment, and the specific display segment is controlled by a voltage value approximately equal to the drive power supply voltage.