CN217426351U - Scanning switch circuit, display driving chip and display device - Google Patents

Abstract

The application relates to a scanning switch circuit, a display driving chip and a display device. The scan switch circuit includes: the device comprises a plurality of line scanning switch modules and a plurality of first control modules. The line scanning switch modules are connected with the line scanning lines of the display screen in a one-to-one correspondence mode. Each first control module is electrically connected with each line scanning switch module in a one-to-one correspondence manner and is used for controlling the on and off of the line scanning switch modules according to the line scanning enabling signals and controlling the transient current magnitude when the line scanning switch modules are on and off according to the control signals and the line scanning enabling signals. In the application, the scanning switch circuit controls the on and off of the line scanning switch module by using the first control module, and controls the transient current during the on and off of the line scanning switch module, so that the transient current is reduced, and the electromagnetic interference is effectively reduced; meanwhile, the capacitive coupling influence of the transient current on the bypass travelling tube channel is reduced, and the current precision and the control precision of the travelling tube channel output are improved.

Description

Scanning switch circuit, display driving chip and display device

Technical Field

The application relates to the technical field of display control, in particular to a scanning switch circuit, a display driving chip and a display device.

Background

Because of its advantages of high brightness, good flexibility, and strong expandability, an LED (Light Emitting Diode) display screen has been widely applied to various scenes such as outdoor advertisements, outdoor performances, and indoor conference halls, and is apparently a development trend of the display industry in the 21 st century.

At present, when an LED display screen works, a scan switch of a line needs to be turned on during scanning of each line, and a scan switch of a previous line needs to be turned off during scanning of a next line, and the scan switch generates a large current at the moment of turning on and off, and the large current affects a scan channel or other circuits and devices around, thereby causing an EM I (Electromagnetic Interference) problem. In the related art, when an EMI problem occurs, modification can be performed only from a circuit board or a chip circuit to reduce EMI, which greatly increases the modification period and cost.

Therefore, there is a need to improve the problems in the above solutions.

SUMMERY OF THE UTILITY MODEL

The present application is directed to a scan switch circuit, a display driver chip and a display device, so as to at least improve the problem of electromagnetic interference.

The purpose of the application is realized by adopting the following technical scheme:

in a first aspect, the present application provides a scan switch circuit, comprising:

the line scanning switch modules are connected with a plurality of line scanning lines of the display screen in a one-to-one correspondence manner; and

and each first control module is electrically connected with each line scanning switch module in a one-to-one correspondence manner and is used for controlling the on and off of the line scanning switch module according to a line scanning enabling signal and controlling the transient current magnitude when the line scanning switch module is on and off according to a control signal and the line scanning enabling signal.

Optionally, each of the line scan switch modules includes N line scan switches, and each of the line scan switches is connected in parallel and is connected to the line scan line and the first control module; wherein N is an integer of 2 or more.

Optionally, the first control module includes a first delay control unit and N-1 second delay control units, the first delay control unit receives the row scan enable signal and is connected to a first row scan switch of the N row scan switches, the N-1 second delay control units receive the row scan enable signal and the control signal and are connected to N-1 row scan switches of the N row scan switches, except for the first row scan switch, in a one-to-one correspondence manner, and the first delay control unit and the N-1 second delay control units control the N row scan switches to operate in a time-sharing manner according to the row scan enable signal and the control signal and the row scan enable signal, respectively.

The embodiment has the advantages that each line scanning switch receives the line scanning enabling signals at different moments under the control of the control signals, different line scanning switches can be switched on or switched off at different moments due to different moments of the received line scanning enabling signals, and the switching on or switching off of each line scanning switch is carried out in a time-sharing mode, so that transient current when the line scanning switches are switched on or switched off is remarkably reduced, the capacitive coupling influence on a bypass line tube channel is further reduced, and the purpose of reducing electromagnetic interference is finally achieved.

Optionally, the first delay control unit includes an inverter, an input end of the inverter receives the row scan enable signal, and an output end of the inverter is connected to the first row scan switch.

Optionally, the second delay control unit includes a nor gate, a first input terminal of the nor gate receives the row scan enable signal, a second input terminal of the nor gate receives the control signal, and an output terminal of the nor gate is connected to one of the N-1 row scan switches.

Optionally, each of the line scan switch modules includes at least one line scan switch, and each of the line scan switches is connected to the line scan line and the first control module.

Optionally, the first control module includes at least one third delay control unit, each third delay control unit is connected to the line scan switch, and controls the transient current magnitude when the line scan switch is turned on or off according to the line scan enable signal and the control signal.

Optionally, each third delay control unit includes a first switch element and a first capacitor, a first end of the first switch element is connected to the line scan switch and receives the line scan enable signal, a control end of the first switch element receives the control signal, a second end of the first switch element is connected to the first end of the first capacitor, and a second end of the first capacitor is grounded.

The embodiment has the advantages that after the first switch element is switched on, the first capacitor starts to be charged and then is discharged, and the charge-discharge process of the first capacitor is utilized to realize the reversal of the level and control the opening degree of the line scanning switch, so that the transient current when the line scanning switch is switched on and switched off is reduced.

Optionally, the scan switch circuit further comprises:

the column scanning switch modules are correspondingly connected with the column scanning lines of the display screen one by one;

and each second control module is electrically connected with each row of scanning switch modules in a one-to-one correspondence manner, and is used for controlling the on and off of the row of scanning switch modules according to a data signal and controlling the transient current of the row of scanning switch modules when the row of scanning switch modules is on and off according to a control signal and the data signal.

In a second aspect, the present application further provides a display driving chip, where the display driving chip includes the scan switch circuit in any of the above embodiments.

In a third aspect, the present application also provides a display device, including:

an array of display cells; and

in the display driving chip of the above embodiment, the display driving chip is connected to the display unit array.

The technical scheme provided by the embodiment of the application can have the following beneficial effects:

in the embodiment of the application, the scan switch circuit controls the on and off of the line scan switch module by using the first control module, and controls the magnitude of the transient current when the line scan switch module is on and off, so that the transient current when the line scan switch module is on and off is reduced, and the electromagnetic interference is effectively reduced; meanwhile, the influence of the transient current on the capacitive coupling of the bypass travelling tube channel is reduced, the current precision output by each travelling tube channel is improved, and the control precision is improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

The present application is further described below with reference to the drawings and examples.

FIG. 1 is a block diagram of a scan switch circuit in one embodiment of the present application;

FIG. 2 is a block diagram of a scan switch circuit in another embodiment of the present application;

FIG. 3 is a block diagram of a scan switch circuit in another embodiment of the present application;

FIG. 4 is a block diagram of a scan switch circuit in another embodiment of the present application;

FIG. 5 is a block diagram of a scan switch circuit in another embodiment of the present application;

FIG. 6 is a schematic circuit diagram of a scan switch circuit in one embodiment of the present application;

FIG. 7 is a block diagram of a scan switch circuit in another embodiment of the present application;

FIG. 8 is a schematic diagram of a third delay control unit in an embodiment of the present application;

FIG. 9 is a schematic diagram of a scan switch circuit in one embodiment of the present application;

FIG. 10 is a schematic circuit diagram of a scan switch circuit according to another embodiment of the present application;

FIG. 11 is a block diagram of a scan switch circuit in another embodiment of the present application;

FIG. 12 is a schematic diagram of a scan switch circuit according to another embodiment of the present application;

FIG. 13 is a schematic view of: FIG. 13a is a schematic diagram of current values generated by a scan switch circuit in one embodiment of the present application, and FIG. 13b is a schematic diagram of current values generated by a scan switch circuit in the related art;

FIG. 14: FIG. 14a is a schematic diagram illustrating voltage values generated by a scan switch circuit according to an embodiment of the present application, and FIG. 14b is a schematic diagram illustrating voltage values generated by a scan switch circuit according to the related art;

FIG. 15 is a schematic diagram of a row line channel in a scan switch circuit according to an embodiment of the present application.

Reference numerals:

10. a display screen; 100. a scan switch circuit; 101. a line scanning switch module; 1011. a line scanning switch; 10111. a first line scanning switch; 102. a first control module; 1021. a first delay control unit; 10211. an inverter; 1022. a second delay control unit; 10221. a NOR gate; 1023. a third delay control unit; 10231. a first switching element; 10232. a first capacitor; 103. a column scan switch module; 104. and a second control module.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features may be combined in any suitable manner in one or more embodiments.

Furthermore, the drawings are merely schematic illustrations of the present application and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus their repetitive description will be omitted. Some of the block diagrams shown in the figures are functional entities and do not necessarily correspond to physically or logically separate entities.

In the exemplary embodiment, firstly, a scan switch circuit 100 is provided, and referring to fig. 1, the scan switch circuit 100 includes: a plurality of line scan switch modules 101 and a plurality of first control modules 102. The plurality of line scan switch modules 101 are connected to the plurality of line scan lines of the display screen 10 in a one-to-one correspondence manner. Each of the first control modules 102 is electrically connected to each of the line scan switch modules 101 in a one-to-one correspondence manner, and is configured to control on and off of the line scan switch module 101 according to a line scan enable signal, and control a transient current magnitude when the line scan switch module 101 is on and off according to a control signal and the line scan enable signal. The first control module 102 can select a simple logic circuit, a digital circuit, or other control circuits to control the magnitude of the transient current when the line scan switch module 101 is turned on and off, so as to reduce the transient current.

Through the scanning switch circuit 100, the first control module 102 is used for controlling the on and off of the line scanning switch module 101, and controlling the magnitude of the transient current when the line scanning switch module 101 is on and off, so that the transient current when the line scanning switch module 101 is on and off is reduced, and the electromagnetic interference is effectively reduced; meanwhile, the influence of the transient current on the capacitive coupling of the bypass travelling tube channel is reduced, the current precision output by each travelling tube channel is improved, and the control precision is improved.

The specific configurations of the line scan switch module 101 and the first control module 102 are described in detail below.

Referring to fig. 2, each of the line scan switch modules 101 includes N line scan switches 1011, and each of the line scan switches 1011 is connected in parallel and is connected to a line scan line and the first control module 102; wherein N is an integer of 2 or more. Each line scanning switch 1011 receives the line scanning enabling signal at different time under the control of the control signal, different line scanning switches 1011 can be switched on or off at different time because the received line scanning enabling signal has different time, and the switching on or off of each line scanning switch 1011 is performed in a time-sharing manner, so that the transient current when the line scanning switches 1011 are switched on or off is remarkably reduced, the capacitive coupling influence on the bypass line pipe channel is further reduced, and the purpose of reducing the electromagnetic interference is finally achieved.

Referring to fig. 3, the first control module 102 includes a first delay control unit 1021 and N-1 second delay control units 1022, wherein the first delay control unit 1021 receives a row scan enable signal and is connected to a first row scan switch 10111 of the N row scan switches 1011, and the N-1 second delay control units 1022 receive the row scan enable signal and a control signal and are connected to N-1 row scan switches 1011 of the N row scan switches 1011, except the first row scan switch 10111, in a one-to-one correspondence manner. The first delay control unit 1021 and the N-1 second delay control units 1022 respectively control the N line scan switches 1011 to operate in a time-sharing manner according to the line scan enable signal, the control signal, and the line scan enable signal. It should be noted that the time-sharing operation of the N line scanning switches 1011 means that the initial operating time nodes of the N line scanning switches 1011 are different, that is, the N line scanning switches 1011 are sequentially turned on according to different control delays and different durations, that is, the operating times of the N line scanning switches 1011 may have an intersection, and it can be understood by those skilled in the art that, in other embodiments, after the N line scanning switches 1011 are sequentially turned on according to different control delays and different durations as needed, the operating times may also have no intersection.

That is, the first delay control unit 1021 controls the first line scan switch 10111 to turn on and off according to the line scan enable signal; the second delay control unit 1022 controls the on and off of the N-1 line scan switches 1011 according to the control signal and the line scan enable signal. The first line scanning switch 10111 realizes the delay operation under the control of the first delay control unit 1021, the remaining N-1 line scanning switches 1011 realize the delay operation under the control of the second delay control unit 1022, and all the N line scanning switches 1011 can realize the time-sharing operation. However, the delay time added by each second delay control unit 1022 to each row scanning switch 1011 is not limited herein, and the delay time of each second delay control unit 1022 may be the same or different.

On the basis of the above first control module 102, the specific structures of the first delay control unit 1021 and the second delay control unit 1022 constituting the first control module 102 are described, respectively.

Referring to fig. 4, the first delay control unit 1021 includes an inverter 10211, an input terminal of the inverter 10211 receives the scan enable signal, and an output terminal of the inverter 10211 is connected to the first scan switch 10111. The inverter 10211 may invert the phase of the input signal by 180 degrees in the circuit, and transmit the signal with a certain transmission frequency to implement the transmission delay of the scan enable signal, so that the first line scan switch 10111 receives the delayed scan enable signal, thereby performing the delayed operation.

Referring to fig. 5, the second delay control unit 1022 includes a nor gate 10221, a first input terminal of the nor gate 10221 receives a row scan enable signal, a second input terminal of the nor gate 10221 receives a control signal, and an output terminal of the nor gate 10221 is connected to one row scan switch 1011 of the N-1 row scan switches 1011. The number of nor gates 10221 included in each second delay control unit 1022 is not limited herein, and may be one or more, and is set according to the time required for delay. The specific delay time is not limited, and may be tens of picoseconds, hundreds of picoseconds, or nanoseconds, for example.

It is understood that, in the above embodiments, referring to fig. 6 in particular to the circuit structure, the inverter 10211 receives the row scan enable signal to control the on and off of the first row scan switch 10111. The nor gate 10221 controls on and off of the N-1 line scan switches 1011 under the control of the control signal and the line scan enable signal. The N line scanning switches 1011 can operate at different delay time lengths, so that time-sharing operation is realized, and thus the transient current of the line scanning switches 1011 during operation is reduced, and the occurrence of electromagnetic interference is remarkably reduced due to lower transient current.

The above is the control of the transient current magnitude when the first control module 102 adopts the digital delay circuit to turn on and off the line scanning switch module 101, and the following is the description of the control of the first control module 102 adopts the analog delay circuit to the line scanning switch module 101.

Referring to fig. 7, each of the line scan switch modules 101 includes at least one line scan switch 1011 (fig. 7 is only an example, and the number of the line scan switches 1011 is not limited), and each of the line scan switches 1011 is connected to a line and the first control module 102. In this embodiment, the first control module 102 may generate different potentials, the turn-on degrees of the line scan switches 1011 corresponding to the different potentials are different, when the potential of the first control module 102 is inverted from 0 to 1 after a certain time, the line scan switches 1011 are completely turned on to be turned on, so as to control the turn-on time of the line scan switches 1011, and the turn-on times of the line scan switches 1011 are different, so as to control the magnitude of the transient current when the line scan switches 1011 are turned on or off.

Referring to fig. 8, the first control module 102 for controlling the line scan switch 1011 includes at least one third delay control unit 1023 (fig. 8 is merely an example, and the number of the third delay control units 1023 is not limited), and each third delay control unit 1023 is connected to the line scan switch 1011 and controls the transient current magnitude when the line scan switch 1011 is turned on or off according to the line scan enable signal and the control signal. The number of the third delay control units 1023 can be set according to the specific parameters of the line scanning switch 1011, and clocks with different frequencies can be obtained.

Referring to fig. 9, each of the third delay control units 1023 includes a first switch element 10231 and a first capacitor 10232, a first end of the first switch element 10231 is connected to the scan switch 1011 and receives the scan enable signal, a control end of the first switch element 10231 receives the control signal, a second end of the first switch element 10231 is connected to a first end of the first capacitor 10232, and a second end of the first capacitor 10232 is grounded. The first switch element 10231 and the first capacitor 10232 in each third delay control unit 1023 are paired, the number of first switch elements 10231 and the number of first capacitors 10232 in each delay control unit 1023 can be configured according to practical application, and the number of first capacitors 10232 connected can be controlled by the first switch element 10231; during specific work, after the first switch element 10231 is switched on, the first capacitor 10232 starts to be charged, the charging degree of the first capacitor 10232 corresponds to a certain electric potential, after the first capacitor 10232 is fully charged, the electric level is inverted from initial 0 to 1, the correspondingly connected line scanning switches 1011 are switched on, therefore, the on-time of each line scanning switch 1011 is controlled by controlling the charging time of the first capacitor 10232, different line scanning switches 1011 correspond to different on-times, the line scanning switches 1011 operate at different time delay durations, time-sharing operation is realized, the transient current size when the corresponding switch-on is obviously reduced, and the influence of EMI is reduced. The principle of turning off the corresponding row scan switch 1011 when the first capacitor 10232 discharges is the same as above.

It is understood that, the specific circuit structure of the above embodiment may be as shown in fig. 10, it should be noted that fig. 10 only illustrates the connection of one scan line, for example, fig. 10 illustrates the specific structure of the row scan switch 1011 and the third delay control unit 1023 connected to the row scan line 1 in fig. 8, and the specific structure of the row scan switch 1011 and the third delay control unit 1023 connected to other scan lines may refer to the scan line 1, which is not described herein in detail; in addition, the number of the first switching elements 10231 and the number of the first capacitors 10232 in each delay control unit 1023 in fig. 10 are each 3 as an example, which does not limit the number of the first switching elements 10231 and the number of the first capacitors 10232 in the delay control unit 1023.

Specifically, the first switch element 10231 and the first capacitor 10232 form a third delay control unit 1023, after the first switch element 10231 receives the control signal and is switched on, the first capacitor 10232 starts to charge, the charging degree of the first capacitor 10232 corresponds to different electric potentials, the different electric potentials lead to different opening degrees of the line scanning switch 1011, when the first capacitor 10232 is fully charged, the electric level is reversed from 1 to 1, so that the line scanning switch 1011 is completely opened to realize conduction, the delay time of different line scanning switches 1011 is different, the transient current when the line scanning switch 1011 is opened is significantly reduced, and the purpose of reducing electromagnetic interference is achieved.

In addition to the above embodiments, it can be understood that, referring to fig. 11, the scan switch circuit 100 may further include: a plurality of column scan switch modules 103 and a plurality of second control modules 104. Specifically, the plurality of column scan switch modules 103 are connected to the plurality of column scan lines of the display screen 10 in a one-to-one correspondence. Each second control module 104 is electrically connected to each column scan switch module 103 in a one-to-one correspondence manner, and is configured to control the column scan switch modules 103 to be turned on and off according to the data signal, and control the transient current magnitude when the column scan switch modules 103 are turned on and off according to the control signal and the data signal. The operation principle of the column scanning switch module 103 and the second control module 104 is the same as that of the row scanning switch module 101 and the first control module 102, and is not repeated here.

Referring to fig. 12, the current control principle of the column scan switch is the same as the circuit control principle of the row scan switch.

With reference to fig. 13, when the number of the row scan switches 1011 is three, by controlling the row scan switch module 101 by the first control module 102, the transient current magnitude when each row scan switch 1011 is turned on or off may be reduced to 1/3; referring to fig. 14, the transient voltage when the line scan switch 1011 is turned on or off also drops significantly. The scanning switch circuit can obviously reduce the influence of EMI, shorten the maintenance period and reduce the maintenance cost.

In addition, referring to fig. 15, a capacitor C exists between the row pipe channel 1 and the row pipe channel 2, and the transient current of the row pipe channel 1 may generate a coupling effect on the bypass row pipe channel 2. The scanning switch circuit reduces the transient current generated by each row tube channel, thereby reducing the coupling influence of the transient current on the bypass row tube channel and further eliminating the electromagnetic interference.

The present application also provides a display driving chip, which includes the scan switch circuit in any of the above embodiments.

The present application also provides a display device, including: the display driving chip comprises a display unit array and the display driving chip of the embodiment, wherein the display driving chip is connected with the display unit array. The display device may be an LED lamp, a display screen 10, or other devices with display function, but is not limited thereto.

It should be noted that although the steps of the methods of the present application are depicted in the drawings in a particular order, this does not require or imply that the steps must be performed in this particular order or that all of the depicted steps must be performed to achieve desirable results. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step execution, and/or one step broken down into multiple step executions, etc. Additionally, it will also be readily appreciated that the steps may be performed synchronously or asynchronously, e.g., among multiple modules/processes/threads.

It should be noted that although several units and modules of the system for action execution are mentioned in the above detailed description, such division is not mandatory. Indeed, the features and functions of two or more units or modules described above may be embodied in one unit or module according to embodiments of the application. Conversely, the features and functions of one unit or module described above may be further divided into embodiments by a plurality of units or modules. The components shown as units or modules may or may not be physical units, i.e. may be located in one place or may be distributed over a plurality of network elements. Some or all of the units or modules can be selected according to actual needs to achieve the purpose of the scheme of the application. One of ordinary skill in the art can understand and implement it without inventive effort.

While the present embodiments have been described with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiments described above, which are meant to be illustrative and not restrictive, and that various changes may be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (11)

1. A scan switch circuit, comprising:

the line scanning switch modules are connected with a plurality of line scanning lines of the display screen in a one-to-one correspondence manner; and

the first control modules are electrically connected with the line scanning switch modules in a one-to-one correspondence mode, and are used for controlling the on and off of the line scanning switch modules according to line scanning enabling signals and controlling the transient current magnitude of the line scanning switch modules during on and off according to control signals and the line scanning enabling signals.

2. The scan switch circuit of claim 1, wherein each of the line scan switch modules comprises N line scan switches, each of the line scan switches being connected in parallel and connected to the line scan lines and the first control module; wherein N is an integer of 2 or more.

3. The scan switch circuit of claim 2, wherein the first control module includes a first delay control unit and N-1 second delay control units, the first delay control unit receives the row scan enable signal and is connected to a first row scan switch of the N row scan switches, the N-1 second delay control units receive the row scan enable signal and the control signal and are connected to N-1 row scan switches of the N row scan switches except the first row scan switch in a one-to-one correspondence, and the first delay control unit and the N-1 second delay control units control the N row scan switches to operate in a time-sharing manner according to the row scan enable signal, the control signal and the row scan enable signal, respectively.

4. The scan switch circuit of claim 3, wherein the first delay control unit comprises an inverter, an input of the inverter receiving the scan enable signal, and an output of the inverter connected to the first scan switch.

5. The scan switch circuit of claim 3, wherein the second delay control unit comprises a NOR gate, a first input of the NOR gate receiving the row scan enable signal, a second input of the NOR gate receiving the control signal, and an output of the NOR gate being connected to one of the N-1 row scan switches.

6. The scan switch circuit of claim 1, wherein each of the row scan switch modules comprises at least one row scan switch, each of the row scan switches being connected to the row scan line and the first control module.

7. The scan switch circuit of claim 6, wherein the first control module comprises at least one third delay control unit, each third delay control unit is connected to the scan line switch, and controls the transient current magnitude when the scan line switch is turned on or off according to the scan line enable signal and the control signal.

8. The scan switch circuit of claim 7, wherein each third delay control unit comprises a first switch element and a first capacitor, a first terminal of the first switch element is connected to the line scan switch and receives the line scan enable signal, a control terminal of the first switch element receives the control signal, a second terminal of the first switch element is connected to the first terminal of the first capacitor, and a second terminal of the first capacitor is grounded.

9. The scan switch circuit of any of claims 1 to 8, further comprising:

the column scanning switch modules are correspondingly connected with the column scanning lines of the display screen one by one;

and each second control module is electrically connected with each column scanning switch module in a one-to-one correspondence manner, and is used for controlling the on and off of the column scanning switch modules according to data signals and controlling the transient current magnitude when the column scanning switch modules are on and off according to control signals and the data signals.

10. A display driver chip comprising the scan switch circuit of any one of claims 1 to 9.

11. A display device, characterized in that the display device comprises:

an array of display cells; and

the display driver chip of claim 10, said display driver chip being coupled to said array of display cells.

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