CN117524112A - Electronic paper driving chip alternating current common voltage circuit and application method - Google Patents

Abstract

The invention relates to an electronic paper driving chip alternating current common voltage circuit and an application method thereof, wherein the electronic paper driving chip alternating current common voltage circuit comprises a VCOM buffer, the VCOM buffer comprises a reference voltage VREF input end and a VCOM output end, the VCOM output end is connected with a stabilizing capacitor and a storage capacitor, the other end of the storage capacitor is connected with a pixel voltage end, the VCOM output end is connected with a switch 1, the other end of the switch 1 is connected with a VGH voltage end, the VCOM output end is simultaneously connected with a switch 2, the other end of the switch 2 is connected with a VGL voltage end, the other end of the stabilizing capacitor is connected with a switch 3, and the other end of the switch 3 is connected with GND. In the invention, when the AC common voltage ACVCOM is in a state, the grounding end of the external stabilizing capacitor at the VCOM output end is suspended by the disconnection switch 3, so that the stabilizing capacitor has no energy loss when the VCOM output end is converted between the VGH voltage end and the VGL voltage end, and the circuit is compatible with various excellent performances of simplifying the circuit, reducing the occupied area of the circuit, reducing the loss, greatly reducing the stabilizing time required by high and low voltage conversion, and the like.

Description

Electronic paper driving chip alternating current common voltage circuit and application method

Technical Field

The invention relates to the technical field of alternating current common voltage of an electronic paper source electrode driving chip, in particular to an alternating current common voltage circuit of the electronic paper driving chip and an application method.

Background

The electronic paper, also called digital paper, is an ultrathin and ultralight display screen, can be regarded as a thin embedded remote control display panel, has the advantages of paper, can continuously convert and refresh display contents like a common liquid crystal display, has the functions of low power consumption and folding and bending, has fine and smooth picture display and wide visual angle, is compared with other display technologies, has the greatest advantages of good visual effect in sunlight, no dead angle and much less electricity than the liquid crystal display, has the revolutionary electronic paper display technology to be applied to portable electronic books, electronic newspapers, IC cards and the like along with the development of the display technology of a series of breakthrough progress, can provide reading functions and use attributes similar to those of traditional books and periodicals.

In order to meet the display requirement of electronic paper, the electronic paper driving chip needs to provide various required voltages, one of which is a common voltage VCOM, the common voltage generally has two working states according to the system requirement, one is a direct current common voltage DCVCOM, and the voltage range is approximately: the other is the ac common voltage ACVCOM of-0.5V to-3.0V, and there are two methods in the prior art, wherein the first method is to control the VCOM buffer to generate the required common voltage through the system, as shown in fig. 1, the method is to generate the dc common voltage DCVCOM and the ac common voltage ACVCOM through the VCOM buffer, and thus, there is a problem that the circuit design is relatively complex and the corresponding circuit area with relatively large occupation is also caused.

Another way is that as shown in fig. 2, there are more switches 1 and 2, and the VCOM output ends can be connected to VGH voltage end and VGL voltage end, and the method is that the dc common voltage DCVCOM is generated by the VCOM buffer as the same as the circuit in fig. 1; when the AC common voltage ACVCOM state is needed, the VCOM buffer can be turned off, the AC common voltage ACVCOM state is realized by the switch 1 and the switch 2, and at the moment, two voltages in the AC common voltage ACVCOM state are respectively supplied by the VGH voltage terminal and the VGL voltage terminal.

Therefore, the electronic paper driving chip ac common voltage circuit and the application method thereof are provided to solve the above problems, and the switch 3 is turned off to suspend the grounding terminal of the stabilizing capacitor when the ac common voltage ACVCOM is in the state, so that the external stabilizing capacitor of the VCOM output terminal will not have energy loss when the VCOM output terminal is switched between the VGH voltage terminal and the VGL voltage terminal, and the required stabilizing time is greatly reduced when the voltage is switched between the high voltage and the low voltage when the ac common voltage ACVCOM is in the state.

Disclosure of Invention

In order to make up the deficiency of the prior art and solve the key technical problems proposed in the background art, the technical scheme adopted by the invention for solving the technical problems is as follows: the utility model provides an electronic paper driving chip alternating current sharing voltage circuit, contains the VCOM buffer, the VCOM buffer contains reference voltage VREF input and VCOM output, VCOM output connects stable condenser and storage capacitor, the pixel voltage end is connected to the storage capacitor other end, VCOM output is connected with switch 1, VGH voltage end is connected to the switch 1 other end, VCOM output is connected with switch 2 simultaneously, VGL voltage end is connected to the switch 2 other end, stable condenser other end is connected with switch 3, GND is connected to the switch 3 other end.

The utility model provides an electronic paper driving chip alternating current sharing voltage circuit, contains the VCOM buffer, the VCOM buffer contains reference voltage VREF input and VCOM output, its characterized in that, VCOM output connects storage capacitor, the pixel voltage end is connected to the storage capacitor other end, VCOM output is connected with switch 1, VGH voltage end is connected to the switch 1 other end, VCOM output is connected with switch 2 simultaneously, VGL voltage end is connected to the switch 2 other end, VCOM output is connected with switch 3, the switch 3 other end is connected with stabilizing capacitor, stabilizing capacitor other end connects GND.

Preferably, the switch 3 is integrated inside the chip, belonging to the on-chip switch.

Preferably, the switch 3 is disposed outside the chip, and the switch 3 is an independent device or an integrated device outside the chip.

Preferably, the VGH voltage terminal is connected to the gate high voltage.

Preferably, the VGL voltage terminal is connected to the gate low voltage.

Preferably, VCOM is a common voltage.

An electronic paper driving chip alternating current common voltage application method comprises the following steps:

step 1: when the DC common voltage DCVCOM is needed, the switch 1, the switch 2 and the switch 3 are turned off, and the VCOM output end outputs the stable DC common voltage DCVCOM by setting the reference voltage VREF input end;

step 2: when the alternating current common voltage ACVCOM is needed, the switch 3 and the switch 2 are disconnected, the switch 1 is turned on, the VCOM output end output voltage is pulled to the VGH voltage end, the switch 2 is turned on, the switch 1 is turned off, and the VCOM output end output voltage is pulled to the VGL voltage end;

step 3: maintaining the switch 3 in an open state, and opening or closing the switch 1 and the switch 2 according to the required frequency, so that the output end continuously outputs square wave alternating current common voltage ACVCOM;

step 4: when the back direct current common voltage DCVCOM is needed, the step 1 is repeated.

Preferably, the supply voltage of the VGH voltage terminal and the VGL voltage terminal is one of an internal gate voltage of the chip, other voltages inside the chip, or an external supply voltage of the chip.

The electronic paper driving chip needs to provide various required voltages, one of which is a common voltage VCOM, and the common voltage VCOM generally has two working states according to the system requirement, and one is a direct current common voltage DCVCOM, and the range is approximately: the other is the ac common voltage accom of-0.5V to-3.0V, as shown in fig. 2, VGH is used to represent VGH voltage terminal voltage, VGL is used to represent VGL voltage terminal voltage, and in the ac common voltage accom state, the voltage range of the VCOM output terminal is VGH to VGL, which causes the electric quantity to change to q=c (VGH-VGL), where C represents the sum of the capacitance of the VCOM output terminal, i.e., c=the stabilizing capacitor capacitance+the storage capacitor capacitance.

The stabilizing capacitor is about 1uF, the sum of the storage capacitors is different according to the display size, resolution, etc., and about 1-100 nf, and in the ac common voltage achom state, it can be seen that one of the main reasons for high power consumption is because of the stabilizing capacitor.

Aiming at the problem of increasing power consumption when VGH and VGL are used in the AC common voltage ACVCOM, the VCOM buffer is not needed to be used in the AC common voltage ACVCOM state, so that an external stable capacitor is not needed at the moment. The specific design is to change the grounding end of the stabilizing capacitor at the VCOM output end to the driving chip to control whether the VCOM output end is grounded or not. The specific working principle is as follows: when the AC common voltage ACVCOM is in a state, the grounding end of the external stable capacitor of the VCOM output end is suspended by the disconnection switch 3, so that the external stable capacitor of the VCOM output end has no energy loss when the VCOM output end is switched between the VGH voltage end and the VGL voltage end, and the required stable time is greatly reduced when the VCOM output end is switched between high and low voltages.

The invention has the beneficial effects that:

in the invention, when the AC common voltage ACVCOM is in a state, the grounding end of the external stabilizing capacitor at the VCOM output end is suspended by the disconnection switch 3, so that the stabilizing capacitor has no energy loss when the VCOM output end is converted between the VGH voltage end and the VGL voltage end, and the circuit is compatible with various excellent performances of simplifying the circuit, reducing the occupied area of the circuit, reducing the loss, greatly reducing the stabilizing time required by high and low voltage conversion, and the like.

Drawings

FIG. 1 is a circuit diagram of prior art 1;

FIG. 2 is a circuit diagram of prior art 2;

FIG. 3 is a diagram of the overall circuit architecture of the present invention;

FIG. 4 is a diagram of the overall circuit architecture of the preferred embodiment of the present invention;

description of the embodiments

The invention is further described in connection with the following detailed description in order to make the technical means, the creation characteristics, the achievement of the purpose and the effect of the invention easy to understand.

Example 1

An electronic paper driving chip alternating current common voltage circuit designed by combining with the embodiment of fig. 3 comprises a VCOM buffer, wherein the VCOM buffer comprises a reference voltage VREF input end and a VCOM output end, and is characterized in that the VCOM output end is connected with a stabilizing capacitor and a storage capacitor, the other end of the storage capacitor is connected with a pixel voltage end, the VCOM output end is connected with a switch 1, the other end of the switch 1 is connected with a VGH voltage end, the VCOM output end is simultaneously connected with a switch 2, the other end of the switch 2 is connected with a VGL voltage end, the other end of the stabilizing capacitor is connected with a switch 3, and the other end of the switch 3 is connected with GND.

In this embodiment, the switch 3 is preferably integrated inside the chip, belonging to a built-in chip switch.

In this embodiment, preferably, the supply voltage of the VGH voltage terminal and the VGL voltage terminal is one of an internal gate voltage of the chip, other voltages in the chip, or an external supply voltage of the chip.

In this embodiment, the VGH voltage terminal is preferably connected to the gate high voltage.

In this embodiment, the VGL voltage terminal is preferably connected to the gate low voltage.

An electronic paper driving chip alternating current common voltage application method comprises the following steps:

step 1: when the DC common voltage DCVCOM is needed, the switch 1, the switch 2 and the switch 3 are turned off, and the VCOM output end outputs the stable DC common voltage DCVCOM by setting the reference voltage VREF input end;

step 2: when the alternating current common voltage ACVCOM is needed, the switch 3 and the switch 2 are disconnected, the switch 1 is turned on, the VCOM output end output voltage is pulled to the VGH voltage end, the switch 2 is turned on, the switch 1 is turned off, and the VCOM output end output voltage is pulled to the VGL voltage end;

step 3: maintaining the switch 3 in an open state, and opening or closing the switch 1 and the switch 2 according to the required frequency, so that the output end continuously outputs square wave alternating current common voltage ACVCOM;

step 4: when the back direct current common voltage DCVCOM is needed, the step 1 is repeated.

In this embodiment, preferably, the supply voltage of the VGH voltage terminal and the VGL voltage terminal is one of an internal gate voltage of the chip, other voltages in the chip, or an external supply voltage of the chip.

Example 2

Referring to fig. 4, an ac common voltage circuit for an electronic paper driving chip according to this embodiment includes a VCOM buffer, where the VCOM buffer includes a reference voltage VREF input end and a VCOM output end, and is characterized in that the VCOM output end is connected with a storage capacitor, the other end of the storage capacitor is connected with a pixel voltage end, the VCOM output end is connected with a switch 1, the other end of the switch 1 is connected with a VGH voltage end, the VCOM output end is simultaneously connected with a switch 2, the other end of the switch 2 is connected with a VGL voltage end, the VCOM output end is connected with a switch 3, the other end of the switch 3 is connected with a stabilizing capacitor, and the other end of the stabilizing capacitor is connected with GND.

In this embodiment, the switch 3 is preferably integrated inside the chip, belonging to a built-in chip switch.

In this embodiment, preferably, the supply voltage of the VGH voltage terminal and the VGL voltage terminal is one of an internal gate voltage of the chip, other voltages in the chip, or an external supply voltage of the chip.

In this embodiment, the VGH voltage terminal is preferably connected to the gate high voltage.

In this embodiment, the VGL voltage terminal is preferably connected to the gate low voltage.

An electronic paper driving chip alternating current common voltage application method comprises the following steps:

step 1: when the DC common voltage DCVCOM is needed, the switch 1, the switch 2 and the switch 3 are turned off, and the VCOM output end outputs the stable DC common voltage DCVCOM by setting the reference voltage VREF input end;

step 2: when the alternating current common voltage ACVCOM is needed, the switch 3 and the switch 2 are disconnected, the switch 1 is turned on, the VCOM output end output voltage is pulled to the VGH voltage end, the switch 2 is turned on, the switch 1 is turned off, and the VCOM output end output voltage is pulled to the VGL voltage end;

step 3: maintaining the switch 3 in an open state, and opening or closing the switch 1 and the switch 2 according to the required frequency, so that the output end continuously outputs square wave alternating current common voltage ACVCOM;

step 4: when the back direct current common voltage DCVCOM is needed, the step 1 is repeated.

In this embodiment, preferably, the supply voltage of the VGH voltage terminal and the VGL voltage terminal is one of an internal gate voltage of the chip, other voltages in the chip, or an external supply voltage of the chip.

The working principle of the invention is as follows:

when the DC common voltage DCVCOM is needed, the switch 1, the switch 2 and the switch 3 are turned off, the stable DC common voltage DCVCOM is output by the VCOM output end through setting the reference voltage VREF input end, when the AC common voltage ACVCOM is needed, the switch 3 and the switch 2 are turned off, the switch 1 is turned on, the VCOM output end output voltage is pulled to the VGH voltage end, the switch 2 is turned on, the switch 1 is turned off, the VCOM output end output voltage is pulled to the VGL voltage end, the switch 3 is kept in an off state, the switch 1 and the switch 2 are turned off or on according to the needed frequency, so that the output end continuously outputs the square wave AC common voltage ACVCOM.

The foregoing has shown and described the basic principles, principal features and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (9)

1. The utility model provides an electronic paper driving chip alternating current sharing voltage circuit, contains the VCOM buffer, the VCOM buffer contains reference voltage VREF input and VCOM output, its characterized in that, VCOM output connects stable condenser and reservoir capacitor, the pixel voltage end is connected to the reservoir capacitor other end, VCOM output is connected with switch 1, VGH voltage end is connected to the switch 1 other end, VCOM output is connected with switch 2 simultaneously, VGL voltage end is connected to the switch 2 other end, the stable condenser other end is connected with switch 3, GND is connected to the switch 3 other end.

2. The utility model provides an electronic paper driving chip alternating current sharing voltage circuit, contains the VCOM buffer, the VCOM buffer contains reference voltage VREF input and VCOM output, its characterized in that, the storage capacitor is connected to the VCOM output, the pixel voltage end is connected to the storage capacitor other end, the VCOM output is connected with switch 1, VGH voltage end is connected to the switch 1 other end, the VCOM output is connected with switch 2 simultaneously, VGL voltage end is connected to the switch 2 other end, the VCOM output is connected with switch 3, the switch 3 other end is connected with stable capacitor, stable capacitor other end is connected with GND.

3. An electronic paper driving chip ac common voltage circuit according to claim 1 or claim 2, wherein the switch 3 is integrated inside the chip and is a built-in switch.

4. An electronic paper driving chip ac common voltage circuit according to claim 1 or claim 2, wherein the switch 3 is disposed outside the chip, and the switch 3 is an independent device or an integrated device outside the chip.

5. The electronic paper driving chip ac common voltage circuit according to claim 1 or claim 2, wherein the supply voltage of the VGH voltage terminal and the VGL voltage terminal is one of an internal gate voltage, other internal voltages, or an external supply voltage.

6. The ac common voltage circuit for an electronic paper driving chip according to claim 1 or claim 2, wherein the VGH voltage terminal is connected to a gate high voltage.

7. The ac common voltage circuit of an electronic paper driving chip according to claim 1 or claim 2, wherein the VGL voltage terminal is connected to a gate low voltage.

8. An electronic paper driving chip alternating current common voltage application method comprises the following steps:

step 1: when the DC common voltage DCVCOM is needed, the switch 1, the switch 2 and the switch 3 are turned off, and the VCOM output end outputs the stable DC common voltage DCVCOM by setting the reference voltage VREF input end;

step 2: when the alternating current common voltage ACVCOM is needed, the switch 3 and the switch 2 are disconnected, the switch 1 is turned on, the VCOM output end output voltage is pulled to the VGH voltage end, the switch 2 is turned on, the switch 1 is turned off, and the VCOM output end output voltage is pulled to the VGL voltage end;

step 3: maintaining the switch 3 in an open state, and opening or closing the switch 1 and the switch 2 according to the required frequency, so that the output end continuously outputs square wave alternating current common voltage ACVCOM;

step 4: when the back direct current common voltage DCVCOM is needed, the step 1 is repeated.

9. The method of claim 8, wherein the supply voltage of the VGH voltage terminal and the VGL voltage terminal is one of an internal gate voltage, other internal voltages, or an external supply voltage.