CN111640404B - Wide-narrow viewing angle switching circuit and display device thereof - Google Patents
Wide-narrow viewing angle switching circuit and display device thereof Download PDFInfo
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- CN111640404B CN111640404B CN202010521295.2A CN202010521295A CN111640404B CN 111640404 B CN111640404 B CN 111640404B CN 202010521295 A CN202010521295 A CN 202010521295A CN 111640404 B CN111640404 B CN 111640404B
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
Abstract
Disclosed is a wide and narrow viewing angle switching circuit, including: the voltage bias module receives a reference square wave voltage and generates a bias voltage according to the reference square wave voltage; the voltage amplification module is connected with the voltage bias module and is used for amplifying the bias voltage by different times respectively to generate a first common voltage and/or a second common voltage; the switching module is connected with the voltage amplification module and outputs the first common voltage or the second common voltage according to a visual angle switching signal, wherein the first common voltage is output when the visual angle switching signal is at a high level; when the visual angle switching signal is at a low level, outputting the second common voltage; the first common voltage is less than the second common voltage. The wide and narrow visual angle switching circuit amplifies the bias voltage by different times, and selects the output voltage to be the first common voltage or the second common voltage through the switching module, so that a DCA module is omitted, the cost is reduced, and the PCBA area is saved.
Description
Technical Field
The invention relates to the technical field of liquid crystal display, in particular to a wide and narrow visual angle switching circuit and a display device thereof.
Background
A Liquid Crystal Display (LCD) has advantages of good picture quality, small size, light weight, low driving voltage, low power consumption, no radiation, and relatively low manufacturing cost, and is dominant in the field of flat panel displays.
With the increasing demand of people for peep-proof of liquid crystal display devices, liquid crystal display devices with switchable wide and narrow viewing angles have been developed. At present, technologies for realizing switching between wide and narrow Viewing angles mainly include HVA (hybrid Viewing Angle) switching technology and PDLC (Polymer Dispersed Liquid Crystal film) switching technology.
FIG. 1 shows a schematic plan view of an electronic terminal of the prior art; fig. 2 shows a block diagram of a wide-narrow viewing angle switching circuit of the related art. Referring to fig. 1 and 2, the electronic terminal includes a display panel 30 whose viewing angle is switchable, a printed circuit board PCBA20 for printing a circuit driving the display panel, and a micro control module MCU 110 for controlling the operation of the electronic terminal. The printed circuit board PCBA20 is electrically connected to the display panel 30 and the micro control module MCU 110, respectively, and the display panel 30 can switch between a wide viewing angle and a narrow viewing angle.
The pcb PCBA20 includes a Digital-to-Analog Converter (DAC) 120, a first voltage follower 130, a second voltage follower 140, and an adder 150, which are used to convert the voltage for driving the display panel, so that the display panel 30 can be switched between a wide viewing angle and a narrow viewing angle.
In this embodiment, the MCU 110 outputs the view switching signal HVA to the DAC 120 according to an operating environment or a user instruction, and specifically, the DAC 120 is connected to the MCU 110 through an I2C bus, where the MCU includes a clock terminal SCL and a data terminal SDA, the clock terminal SCL is used for transmitting the clock signal, and the data terminal SDA is used for transmitting the view switching signal HVA. The I2C bus also includes a clock terminal SCL and a data terminal SDA, so that the MCU 110 writes different instructions to the DAC 120 through the I2C bus channel, and the DAC 120 outputs different voltages according to the different instructions. Since the voltage generated by the DAC 120 has a certain system offset, offset compensation voltages FB01 and FB02 are generated by the first voltage follower block 130 and the second voltage follower block 140 according to the negative input voltage VS-, and FB01 and FB02 are added by the addition block 150, so as to obtain the driving voltage Vout required by the display panel 30.
In this embodiment, since the DAC 120 occupies a serial interface, the cost is slightly higher than that of a common device, the size is large, the PCBA space is occupied, and the serial interface is occupied, so that a low-cost and small-size wide-narrow viewing angle switching circuit is required.
Disclosure of Invention
In view of the foregoing problems, it is an object of the present invention to provide a wide and narrow viewing angle switching circuit, which obtains a first common voltage and a second common voltage of different magnitudes and outputs the first common voltage or the second common voltage through a voltage amplifying module and a switching module, thereby reducing cost and volume.
According to an aspect of the present invention, there is provided a wide and narrow viewing angle switching circuit including: the voltage bias module receives a reference square wave voltage and generates a bias voltage according to the reference square wave voltage; the voltage amplification module is connected with the voltage bias module and is used for amplifying the bias voltage by different times respectively to generate a first common voltage and/or a second common voltage; the switching module is connected with the voltage amplifying module and outputs the first common voltage or the second common voltage according to the visual angle switching signal; the control module is connected with the switching module and generates the visual angle switching signal, wherein the first common voltage is output when the visual angle switching signal is at a high level; when the visual angle switching signal is at a low level, outputting the second common voltage; the first common voltage is less than the second common voltage.
Preferably, the voltage amplifying module is connected in series with the switching module, and the voltage amplifying module includes a first voltage amplifying module and a second voltage amplifying module connected in parallel, where the first voltage amplifying module is configured to generate a first common voltage, and the second voltage amplifying module is configured to generate a second common voltage.
Preferably, the switching module includes two input ends and an output end, and the input end of the switching module is connected to the output ends of the first voltage amplification module and the second voltage amplification module, respectively.
Preferably, the voltage bias module includes an operational amplifier and a plurality of resistors, a forward input end of the operational amplifier is grounded through a resistor, a backward input end of the operational amplifier receives the reference square-wave voltage through a resistor, and the backward input end and the output end of the operational amplifier are connected through a resistor and are connected with the backward input end through a resistor and a reference voltage.
Preferably, the voltage amplifying module includes an operational amplifier and a plurality of resistors, a forward input end of the operational amplifier is grounded through a resistor, a reverse input end of the operational amplifier is connected with the output end of the voltage bias module through a resistor, and the reverse input end and the output end of the operational amplifier are connected through a resistor.
Preferably, the voltage amplifying module is connected in parallel with the switching module.
Preferably, the switching module includes an input end and two output ends, the input end of the switching module is connected to the input end of the voltage amplification module, and the output ends of the switching module are respectively connected to the output ends of the voltage amplification module.
Preferably, the output end of the switching module is connected to the output end of the voltage amplifying module through resistors with different resistance values.
Preferably, the reference square wave voltage is generated by a micro control module or a timing controller.
According to another aspect of the present invention, there is provided a display device comprising the foregoing wide and narrow viewing angle switching circuit.
In the wide and narrow visual angle switching circuit, the micro control module MCU is used for generating the reference square wave, the bias voltage is respectively amplified through the two voltage amplification modules to obtain the first public voltage and the second public voltage, and the switching module selects and outputs the first public voltage or the second public voltage according to the visual angle switching signal.
In a preferred embodiment, the switching module selects resistors with different resistances according to the viewing angle switching signal, so that the voltage amplifying module performs amplification of different multiples to obtain the first common voltage or the second common voltage. Because a voltage amplification module is reduced, the product cost is further reduced, and the area of the PCBA is saved.
In a preferred embodiment, the reference square wave may also be generated by the timing controller TCON, so that the micro control module MCU and the peripheral circuits of the micro control module MCU may be further omitted.
Drawings
The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:
FIG. 1 shows a schematic plan view of an electronic terminal of the prior art;
fig. 2 is a block diagram showing a wide and narrow viewing angle switching circuit of the related art;
fig. 3 is a block diagram showing a wide and narrow viewing angle switching circuit according to an embodiment of the present invention;
fig. 4a to 4f are simplified circuit diagrams and voltage test charts of the wide and narrow viewing angle switching circuit according to the embodiment of the present invention;
fig. 5a is a diagram illustrating a structure of a wide-narrow viewing angle switching circuit according to a first embodiment of the present invention;
fig. 5b is a circuit diagram of a wide-narrow viewing angle switching circuit according to a first embodiment of the present invention;
fig. 5c is a node voltage diagram of a circuit diagram of a wide-narrow viewing angle switching circuit according to a first embodiment of the present invention;
fig. 6a is a structural diagram of a wide and narrow viewing angle switching circuit according to a second embodiment of the present invention;
fig. 6b is a circuit diagram of a wide and narrow viewing angle switching circuit according to a second embodiment of the present invention;
fig. 6c is a node voltage diagram of a circuit diagram of a wide-and-narrow-viewing-angle switching circuit according to a second embodiment of the present invention.
Detailed Description
Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Like elements in the various figures are denoted by the same or similar reference numerals. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale.
The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples.
First embodiment
Fig. 3 is a block diagram showing a wide-and-narrow viewing angle switching circuit according to an embodiment of the present invention.
Referring to fig. 3, the wide and narrow viewing angle switching circuit 200 according to the embodiment of the present invention includes a micro control module 210, a voltage bias module 220, a voltage amplification module 230, a switching module 240, and a control module 250. The voltage bias module 220 is connected to the micro control module 210, and is configured to receive a reference square wave generated by the micro control module 210, and bias the received square wave to obtain a bias voltage, where a center voltage of the bias voltage is 0. The voltage amplifying module 230 is connected to the voltage bias module 220, and is configured to amplify the bias voltage to obtain a first common voltage and/or a second common voltage, where the first common voltage is, for example, ± 2.5V, and the second common voltage is, for example, ± 5V. The switching module 240 is respectively connected to the voltage amplifying module 230 and the control module 250, and is configured to receive the viewing angle switching signal HVA of the control module 250 and output a corresponding first common voltage or a second common voltage as a driving voltage Vout of the display panel according to the viewing angle switching signal HVA.
When the view switching signal HVA is a high-level H signal, the driving voltage Vout output by the switching module 240 is in a wide view level state, for example, a first common voltage ± 2.5V; when the view angle switching signal HVA is a low level L signal, the driving voltage Vout output by the switching module 240 is in a narrow view angle level state, for example, the second common voltage ± 5V.
In this embodiment, the voltage amplifying module 230 and the switching module 240 have at least two different connection modes to output different voltages. For example, the first way is that the voltage amplifying module 230 amplifies the bias voltage to obtain two voltages, namely, a first common voltage and a second common voltage, respectively, and the switching module 240 selects and outputs the voltage of the first common voltage or the second common voltage according to the view switching signal HVA. For example, the second method is to connect the switching module 240 to resistors with different resistances by using the view switching signal HVA, and the voltage amplifying module 230 amplifies voltages of different multiples according to the resistors with different resistances connected to the switching module 240 to obtain the first common voltage or the second common voltage.
Fig. 4a to 4f are simplified circuit diagrams and voltage test diagrams of the wide and narrow viewing angle switching circuit according to the embodiment of the present invention, which simply illustrate two different connection mode principles of the voltage amplifying module 230 and the switching module 240.
Referring to fig. 4a to 4c, fig. 4a is a single-pole double-throw switch, which includes an input terminal NC and an input terminal NO, an output terminal COM, and a viewing angle switching signal input terminal IN, and the output terminal COM is controlled to be connected to the input terminal NC or NO by a high-low level of the viewing angle switching signal.
Fig. 4b and 4c show the voltage at the output terminal COM when the voltage at the input terminal NC is ± 5V, the voltage at the input terminal NO is ± 2.5V, and the voltage at the viewing angle switching signal input terminal IN is 0V or 3.3V. As can be seen from fig. 4b and 4c, when the voltage at the input terminal IN of the view switching signal is 0V, the input terminal NC is conducted with the output terminal COM, and the voltage at the output terminal COM is ± 5V; when the voltage at the input end IN of the visual angle switching signal is 3.3V, the input end NO is conducted with the output end COM, and the voltage at the output end COM is +/-2.5V.
Referring to fig. 4d to 4f, fig. 4d is a single-pole double-throw switch, which includes an output terminal NC and an output terminal NO, an input terminal COM and a viewing angle switching signal input terminal IN, and the input terminal COM is connected to the output terminal NC or NO through a high-low level control input terminal of a viewing angle switching signal.
Fig. 4e and 4f show the voltage conditions of the output NC or NO when the input COM is ± 2.5V and the voltage of the view angle switching signal input IN is 0V or 3.3V. As can be seen from fig. 4e and 4f, when the voltage at the input terminal IN of the view switching signal is 0V, the output terminal NC is conducted with the input terminal COM, the voltage at the output terminal NC is ± 2.5V, and the voltage at the output terminal NO is 0V; when the voltage of the input terminal IN of the view angle switching signal is 3.3V, the output terminal NO is conducted with the input terminal COM, the voltage of the output terminal NC is 0V, and the voltage of the output terminal NO is ± 2.5V.
According to the embodiments shown in fig. 4a to 4f, the switching circuit for switching a wide and a narrow viewing angle of the present application can achieve the purpose of outputting different voltages according to different viewing angle switching signals by the above two methods.
Fig. 5a is a diagram illustrating a structure of a wide-narrow viewing angle switching circuit according to a first embodiment of the present invention; fig. 5b is a circuit diagram of a wide-narrow viewing angle switching circuit according to a first embodiment of the present invention; fig. 5c is a node voltage diagram of a circuit diagram of the wide and narrow viewing angle switching circuit according to the first embodiment of the present invention. The wide and narrow viewing angle switching circuit according to the first embodiment of the present invention is designed according to the simplified circuit diagrams and the voltage test diagrams shown in fig. 4a to 4c, for example.
Referring to fig. 5a, in the wide and narrow viewing angle switching circuit 201 according to the first embodiment of the present invention, the voltage amplifying module 230 includes a first voltage amplifying module 231 and a second voltage amplifying module 232 connected in parallel, and are respectively configured to amplify the bias voltage output by the voltage biasing module 220 by different multiples, so as to obtain a first common voltage and a second common voltage. In this embodiment, for example, the voltage amplified by the first voltage amplifying module 231 is a first common voltage, the voltage amplified by the second voltage amplifying module 232 is a second common voltage, and the switching module 240 controls the output driving voltage Vout to be the first common voltage or the second common voltage according to the viewing angle switching signal HVA of the control module 250. In this embodiment, the first common voltage is ± 2.5V, and the second common voltage is ± 5V.
Referring to fig. 5b, in this embodiment, the voltage bias module 220 includes an operational amplifier OP1, resistors R1, R2, R3 and R4. The positive input end of the operational amplifier OP1 is grounded through a resistor R1, the reverse input end is connected to the first end of the resistor R2, the second end of the resistor R2 is connected to the output end of the MCU210 to receive a reference square wave, the two ends of the resistor R4 are connected to the reverse input end and the output end of the operational amplifier OP1, the first end of the resistor R3 is connected to the reverse input end of the operational amplifier OP1, and the second end is connected to a reference voltage Verf, so that the voltage bias module 220 can bias the reference square wave according to the reference voltage Verf to obtain a bias voltage. The operational amplifier OP1 further includes a positive power supply terminal connected to VCC and a negative power supply terminal connected to ground.
In other preferred embodiments, the reference square wave received by the inverting input terminal of the operational amplifier OP1 may also be generated by a Timing Controller (TCON), and further, the micro control module MCU210 and peripheral circuits of the micro control module MCU may be omitted, so as to reduce the cost and save the PCBA area.
The first voltage amplifying module 231 includes an operational amplifier OP2, resistors R5, R6 and R7. The positive input terminal of the operational amplifier OP2 is grounded through a resistor R5, the negative input terminal is connected to the output terminal of the voltage bias module 220 through a resistor R6 to receive the biased voltage, and two ends of the resistor R7 are respectively connected to the negative input terminal and the output terminal of the operational amplifier OP2, so that the first voltage amplification module 231 amplifies the biased voltage to obtain a first common voltage, where the first common voltage is, for example, ± 2.5V. The operational amplifier OP2 further includes a positive power supply terminal connected to VCC and a negative power supply terminal connected to ground.
The second voltage amplifying module 232 includes an operational amplifier OP3, resistors R8, R9 and R10. In the first embodiment, the second voltage amplifying module 232 is used for amplifying the bias voltage to obtain a second common voltage, which is, for example, ± 5V, like the first voltage amplifying module 231. The first voltage amplifying module 231 and the second voltage amplifying module 232 have different amplification factors due to different resistances of the resistors R7 and R10 respectively connected to the inverting input terminal and the output terminal of the operational amplifier. Therefore, the amplification factors of the first and second voltage amplification modules 231 and 232 may be changed by changing the resistance values of the resistors R7 and R10. The operational amplifier OP3 further includes a positive power supply terminal connected to VCC and a negative power supply terminal connected to ground.
The switching module 240 is a Single Pole Double Throw (SPDT) switch, the switch S1 is connected to the output terminal of the first voltage amplifying module 231, and the switch S2 is connected to the output terminal of the second voltage amplifying module 232. The switch module 240 selects whether the switch S1 is turned on or the switch S2 is turned on according to the high-low level of the view switching signal HVA output by the control module 250. For example, when the viewing angle switching signal HVA is at a high level, the switch S1 is turned on, and the switching module 240 outputs the first common voltage amplified by the first voltage amplifying module 231; when the viewing angle switching signal HVA is at a low level, the switch S2 is turned on, and the switching module 240 outputs the second common voltage amplified by the second voltage amplifying module 232.
Fig. 5C is a node voltage diagram of a circuit diagram of the wide and narrow viewing angle switching circuit according to the first embodiment of the present invention, in which voltage waveform diagrams and values of three nodes of the output terminal (point a in fig. 5B) of the MCU210, the output terminal (point B in fig. 5B) of the voltage bias module 220 and the output terminal (point C in fig. 5B) of the switching module 240 in the wide and narrow viewing angle switching circuit 201 are read by an oscilloscope. As can be seen from fig. 5b and 5c, the voltage of the reference square wave is 0-3.3V, and is ± 1.65V after being biased, and the output voltage is ± 2.5V of the first common voltage because the switch S1 is turned on.
Second embodiment
Fig. 6a is a block diagram showing a wide and narrow viewing angle switching circuit according to a second embodiment of the present invention; fig. 6b is a circuit diagram of a wide and narrow viewing angle switching circuit according to a second embodiment of the present invention; fig. 6c is a node voltage diagram of a circuit diagram of a wide-and-narrow-viewing-angle switching circuit according to a second embodiment of the present invention. The wide-narrow viewing angle switching circuit according to the first embodiment of the present invention is designed according to the simplified circuit diagram and the voltage test diagram shown in fig. 4d to 4 f. Compared with the first embodiment, the wide and narrow viewing angle switching circuit of the second embodiment has only one voltage amplification module, the circuit structure is simpler, the occupied PCBA area is smaller, and the cost is lower.
Referring to fig. 6a, in the wide and narrow viewing angle switching circuit 202 according to the second embodiment of the present invention, the first voltage amplifying module 231 is connected in parallel to the switching module 240, and the switching module 240 is connected to resistors with different resistances, so as to amplify the bias voltage output by the voltage bias module 220 by different times to obtain the first common voltage or the second common voltage. In this embodiment, for example, the voltage output by the switching module 240 when the first output terminal is turned on is the first common voltage, and the voltage output by the second output terminal is the second common voltage, and the switching module 240 controls the first output terminal to be turned on or the second output terminal to be turned on according to the view angle switching signal HVA of the control module 250.
Referring to fig. 6b, in this embodiment, the voltage bias module 220 includes an operational amplifier OP4, resistors R12, R13, R14 and R15. The positive input end of the operational amplifier OP4 is grounded through a resistor R12, the negative input end is connected to the first end of a resistor R13, the second end of the resistor R13 is connected to the output end of the MCU210 to receive the reference square wave, the two ends of the resistor R15 are connected to the negative input end and the output end of the operational amplifier OP4, the first end of the resistor R14 is connected to the negative input end of the operational amplifier OP4, and the second end is connected to the reference voltage Verf, so that the voltage bias module 220 can bias the reference square wave according to the reference voltage Verf to obtain the bias voltage. The operational amplifier OP4 further includes a positive power supply terminal connected to VCC and a negative power supply terminal connected to ground.
In other preferred embodiments, the reference square wave received by the inverting input terminal of the operational amplifier OP4 may also be generated by a Timing Controller (TCON), which further may omit the micro control module MCU210 and the peripheral circuits of the micro control module MCU, thereby reducing the cost and saving the PCBA area.
The first voltage amplifying module 231 includes an operational amplifier OP5, resistors R16 and R17. The positive input terminal of the operational amplifier OP5 is grounded through a resistor R16, and the negative input terminal is connected to the output terminal of the voltage bias module 220 through a resistor R17 to receive the bias voltage. The operational amplifier OP5 further includes a positive power supply terminal connected to VCC and a negative power supply terminal connected to ground.
The switching module 240 includes a Single Pole Double Throw (SPDT) switch and resistors R18 and R19, one end of the resistor R18 is connected to the inverting input terminal of the operational amplifier OP5 through a switch S4, the other end is connected to the output terminal of the operational amplifier OP5 for obtaining a first common voltage, one end of the resistor R19 is connected to the inverting input terminal of the operational amplifier OP5 through a switch S5, the other end is connected to the output terminal of the operational amplifier OP5 for obtaining a second common voltage, and the resistors R18 and R19 have different resistances, for example, the resistance of R19 is twice that of R18. The switch module 240 selects whether the switch S4 is turned on or the switch S5 is turned on according to the high-low level of the view switching signal HVA output by the control module 250. For example, when the view angle switching signal HVA is at a high level, the switch S4 is turned on, and the voltage output by the first voltage amplifying module 231 is the first common voltage; when the viewing angle switching signal HVA is at a low level, the switch S5 is turned on, and the voltage output by the first voltage amplifying module 231 is the second common voltage. In this embodiment, the switching module 240 changes the voltage of the output by changing the resistance of a resistor connected between the inverting input terminal and the output terminal of the operational amplifier OP 5.
Fig. 6C is a node voltage diagram of a circuit diagram of a wide and narrow viewing angle switching circuit according to a second embodiment of the present invention, in which voltage waveform diagrams and values of three nodes, i.e., an output terminal (point a in fig. 6B) of the MCU210, an output terminal (point B in fig. 6B) of the voltage bias module 220, and an output terminal (point C in fig. 6B) of the switching module 240 in the wide and narrow viewing angle switching circuit 202 are read by an oscilloscope. As can be seen from fig. 6b and 6c, the voltage of the reference square wave is 0-3.3V, and is ± 1.65V after being biased, and the output voltage is ± 2.5V of the first common voltage because the switch S4 is turned on.
The application also provides a display device which comprises the wide and narrow visual angle switching circuit.
In the wide and narrow visual angle switching circuit, the micro control module MCU is used for generating the reference square wave, the bias voltage is respectively amplified through the two voltage amplification modules to obtain the first public voltage and the second public voltage, and the switching module selects the voltage needing to be output to be the first public voltage or the second public voltage according to the visual angle switching signal.
In a preferred embodiment, the switching module selects resistors with different resistances according to the viewing angle switching signal, so that the voltage amplifying module performs amplification of different multiples, thereby obtaining the first common voltage or the second common voltage. Because a voltage amplification module is reduced, the product cost is further reduced, and the area of the PCBA is saved.
In a preferred embodiment, the reference square wave may also be generated by the timing controller TCON, so that the micro control module MCU and the peripheral circuits of the micro control module MCU may be further omitted.
While embodiments in accordance with the invention have been described above, these embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments described. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. The invention is limited only by the claims and their full scope and equivalents.
Claims (8)
1. A wide and narrow viewing angle switching circuit, comprising:
the microcontroller module or the time schedule controller is used for generating a reference square wave;
the voltage bias module receives a reference square wave voltage and generates a bias voltage according to the reference square wave voltage, and the waveform of the bias voltage is at least in the period when the view angle switching signal is at a high level and a low level; the voltage bias module comprises a first operational amplifier and four resistors, wherein the forward input end of the first operational amplifier is grounded through the first resistor, the reverse input end of the first operational amplifier receives a reference square wave voltage through the second resistor, the reverse input end and the output end of the first operational amplifier are connected through the fourth resistor, and the reverse input end of the first operational amplifier is connected with a reference voltage through the third resistor;
the voltage amplification module is connected with the voltage bias module and is used for amplifying the bias voltage by different multiples to generate a first public voltage and/or a second public voltage;
the switching module is connected with the voltage amplifying module and outputs the first common voltage or the second common voltage according to the visual angle switching signal;
a control module connected with the switching module for generating the visual angle switching signal,
when the visual angle switching signal is at a high level, outputting the first common voltage;
when the visual angle switching signal is at a low level, outputting the second common voltage;
the first common voltage is less than the second common voltage, and the first common voltage and the second common voltage are alternating-current voltages.
2. The wide and narrow viewing angle switching circuit according to claim 1, wherein the voltage amplifying module is connected in series with the switching module, the voltage amplifying module includes a first voltage amplifying module and a second voltage amplifying module connected in parallel, the first voltage amplifying module is configured to generate a first common voltage, and the second voltage amplifying module is configured to generate a second common voltage.
3. The wide and narrow viewing angle switching circuit according to claim 2, wherein the switching module includes two input terminals and one output terminal, and the input terminals of the switching module are respectively connected to the output terminals of the first voltage amplifying module and the second voltage amplifying module.
4. The wide and narrow viewing angle switching circuit according to claim 1, wherein the voltage amplifying module includes a second operational amplifier, a third operational amplifier and six resistors, a forward input terminal of the second operational amplifier is grounded through a fifth resistor, a reverse input terminal of the second operational amplifier is connected with the output terminal of the voltage bias module through a sixth resistor, and the reverse input terminal and the output terminal of the second operational amplifier are connected through a seventh resistor; the positive input end of the third operational amplifier is grounded through an eighth resistor, the reverse input end of the third operational amplifier is connected with the output end of the voltage bias module through a ninth resistor, and the reverse input end and the output end of the third operational amplifier are connected through a tenth resistor.
5. The wide and narrow viewing angle switching circuit of claim 1, wherein the voltage amplifying module is connected in parallel with the switching module.
6. The wide and narrow viewing angle switching circuit according to claim 5, wherein the switching module includes an input terminal and two output terminals, the input terminal of the switching module is connected to the input terminal of the voltage amplifying module, and the output terminals of the switching module are respectively connected to the output terminals of the voltage amplifying module.
7. The wide and narrow viewing angle switching circuit according to claim 6, wherein the output terminals of the switching module are respectively connected to the output terminals of the voltage amplifying module through resistors with different resistances.
8. A display device comprising the wide-narrow viewing angle switching circuit according to any one of claims 1 to 7.
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