CN2240163Y - Display Automatic Backlighting Calculator - Google Patents

Abstract

The utility model relates to an automatic background illumination light calculator of display screen, including keyboard (1), microprocessor (2) and liquid crystal display (3) with the circuit connection in proper order to and automatic background light takes place part (4). The utility model discloses owing to can open and close the background illumination light to liquid crystal display (3) according to ambient lighting luminance is automatic, therefore widen the application scenario of calculator to and calculate the function in succession for the job site that changes at ambient lighting and provide convenience.

Description

Display Automatic Backlighting Calculator

The utility model relates to an improved calculator, in particular to a calculator with the function of automatically opening and closing the background lighting of a display screen.

At present, commercially available calculators do not have the function of automatically providing backlight for the display screen. Although there are electronic light-emitting panels, so in some occasions where the light is insufficient or does not allow light work, such as the driving of aircraft cockpits, passenger cabins, ships and trains, etc. Offices, hospitals, laboratories, and some industries (bars, nightclubs, etc.) that require dark background light, it is inconvenient to use a calculator, or even unusable.

The purpose of the utility model is to provide a calculator which can automatically control the lighting background light of the liquid crystal display screen according to the brightness and darkness of the working environment.

The utility model is realized in that it includes an automatic background light generating part except the keyboard, the microprocessor and the liquid crystal display screen which are sequentially connected with the circuit. This automatic background light generating part utilizes existing market sales to include photosensitive switch, excitation power supply and electronic light-emitting board (electronic liquid crystal plate, light-emitting diode etc.), which are connected with circuit successively. The on-off state of photosensitive switch is determined by the bright condition of the place where calculator of the utility model is located. When the light is insufficient or the sky is dark, the light-sensitive switch is turned on to make the excitation current work, thereby causing the electronic light-emitting panel to emit light and providing background light for the liquid crystal display. Under normal brightness, when the user can clearly see the displayed numbers on the LCD screen, the light sensor switch is turned off, cutting off the working circuit of the excitation current, thus making the electronic light-emitting board not work, that is, no background light is provided to the LCD screen.

The advantages of the utility model are: 1. Widen the occasions where the calculator is used, so that it can be used normally in the case of insufficient light or the occasion where the work cannot be performed in a bright environment; And hinder the user to continue computing operations.

The utility model is implemented by the following drawings.

Fig. 1 is a circuit structure block diagram of the utility model.

Fig. 2 is a schematic circuit diagram of the automatic background light generating part of the present invention.

Fig. 3 is a schematic structural view of the utility model.

Below we give an excellent embodiment of the utility model according to Fig. 1-Fig. 3, and further provide the technical details of the utility model in combination with the description of the embodiment.

Please refer to Fig. 1, as can be seen from the figure, the utility model comprises a keyboard 1, a microprocessor 2, and a liquid crystal display 3 connected successively with a circuit, and an automatic backlight generating part in addition.

Please refer to Fig. 2, as shown in the figure, the automatic background light generating part 4 among the utility model comprises the photosensitive switch 41 that connects with the circuit successively as composite structure, and it is the photosensitive amplifier 411 that is made of phototransistor Q1 and resistance R1 , N-P-N type triode amplifier 412 and P-N-P triode 413 are sequentially connected, and the triode 413 is connected in series to the power supply circuit of the excitation power supply 42 . In this way, when the ambient light is bright, the phototransistor amplifier 411 is turned on, and the amplifier 412 is turned off, so that the triode 413 is turned off, and the power supply current of the excitation power supply 42 is cut off. Conversely, when the ambient light is insufficient or dark, the phototransistor amplifier 411 does not work, thus the amplifier 412 is driven, because the triode Q2 forming the amplifier 412 is turned on, the triode 413 is driven, thus the power supply of the excitation power supply 42 is turned on, Finally, the electronic light-emitting panel 43 is illuminated to provide background light for the liquid crystal display 3 . In this embodiment, the excitation power supply 42 includes an oscillator 421 and a transformer 422 connected in sequence in a circuit. The triode Q3 in the oscillator 421 is an N-P-N type triode, its emitter is connected to the center tap of the primary coil of the transformer 422, its collector is connected to the power supply through the triode 413, one end of the primary coil 4221 is grounded, and the other end is connected to the capacitor C1 is connected, the other end of the capacitor C1 is connected to the base and collector of the transistor Q3 through the resistors R4 and R3 respectively, and the capacitor C2 is connected between the collector and the base of the transistor Q3.

Please refer to Fig. 3, as can be seen from the figure, the electronic luminescent plate 43 is installed on the rear side of the liquid crystal display screen 3, and the phototransistor Q1 in the phototransistor 41 in the photosensitive switch 41 is then installed in the utility model that can detect ambient light brightness. Appropriate position, in this embodiment it is installed on the middle top of the liquid crystal display 3, so that it will not affect the display data, but also can reflect the ambient brightness on the display 3. Below we list the relevant components and parts parameters in this embodiment:

R1＝150K, R2＝10K, R3＝680

R4＝10， R5＝4.7K

Q1 is a PT370 photosensitive transistor C1=6.8u, C2=0.047u

Claims (4)

1. display screen automatic background optical illumination counter, comprise the keyboard (1), microprocessor (2), LCDs (3) and the electron luminescence plate (43) that connect mutually with circuit successively, it is characterized in that automatic background light generation part (4) that connects mutually with circuit in turn by light sensation switch (41), excitation power supply (42) and electron luminescence plate (43) in addition, and this electron luminescence plate (43) is installed in the back of LCDs (3); And have a phototriode Q1 to be installed on the appropriate location of an energy testing ambient brightness in this light sensation switch (41).

2. according to the described counter of claim 1, it is characterized in that set light activated switch (41) is the composite switch structure that comprises that the phototriode amplifier (411), N-P-N type triode amplifier (412) and the P-N-P type triode (413) that are made of resistance R 1 and phototriode Q1 are coupled to circuit successively.

3. according to the described counter of claim 1, it is characterized in that excitation power supply (42) comprises oscillator (421) and the transformer (422) that connects with circuit successively.

4. according to claim 1 or 2 described counters, it is characterized in that phototriode Q1 is installed on the LCDs (3).

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