TW202137195A - Scanning-type display and driving method thereof capable of preventing the frame displayed by the scanning-type display from tearing or interruption - Google Patents

Abstract

Provided is a scanning-type display including a backlight module, a display module, a control module and a driving module which have a common cathode architecture. The backlight module includes a plurality of light emitting diodes respectively and correspondingly disposed among matrices defined by a plurality of scanning lines and a plurality of data lines. The control module generates an image stream and a synchronous control signal. The driving module is electrically connected with the control module to receive the synchronous control signal and the image stream. The driving module generates a plurality of switching signals respectively corresponding to the plurality of scanning lines to the backlight module according to the synchronous control signal and the image stream so as to control the backlight module to transmit a reference voltage to the scanning lines of each row. The driving module further generates an image updating signal according to the synchronous control signal and the switching signal corresponding to the scanning lines of last row, wherein the image updating signal relates to image updating of the display module.

Description

Scanning display and its driving method

The present invention relates to a display technology in the field of light emitting diodes, in particular to a scanning display and a driving method thereof.

The existing driving device for driving a scanning display for image display includes a control module and a driving module. The driving module receives a synchronization control signal related to image display and update from the control module, and receives an image stream from the control module. The image stream has a plurality of image data related to the screen to be displayed on the scanning display. The driving module drives the scanning display according to the synchronization control signal and the image stream, so that a backlight module including a light-emitting diode array in the scanning display is controlled by the synchronization control signal At the same time, it becomes brighter or darker, and a display module in the scanning display displays and updates the image data of the image stream according to the frequency of the synchronization control signal. The synchronization control signal is a vertical synchronization (V-sync) periodic signal, and its frequency is, for example, 60 Hz. That is to say, the scanning display will periodically update the displayed picture. A frame rate of the screen is the same as the frequency of the synchronization control signal.

However, when the synchronization control signal is a non-periodic signal, and the backlight module is a scanning backlight module that is triggered by the synchronization control signal and adopts scanning control to sequentially emit light row by row, the aforementioned conventional scanning display The driving method may cause the screen displayed by the display module to be torn or interrupted. Therefore, there is still room for improvement in the existing driving method of the scanning display.

Therefore, a first objective of the present invention is to provide a scanning display that can avoid tearing or interruption of the screen displayed on the scanning display.

Therefore, the scanning display includes a backlight module and a display module.

The backlight module receives a reference voltage and includes a light-emitting diode array with a common cathode structure. The light-emitting diode array includes: a plurality of scan lines arranged in a row direction with each other, and a plurality of scan lines arranged perpendicular to each other in a column direction. The data lines of the line and a plurality of light-emitting diodes respectively correspondingly arranged between the matrix defined by the plurality of scan lines and the plurality of data lines, each light-emitting diode has an electrical connection corresponding to the scan The cathode of the line and the anode of the data line corresponding to an electrical connection. The display module is used for displaying images. The driving device includes a control module and a driving module. The control module generates an image stream and a synchronization control signal.

The driving module is electrically connected to the backlight module and the display module, and is electrically connected to the control module to receive the synchronization control signal and the image stream. The driving module generates a plurality of switching signals corresponding to a plurality of scan lines to the backlight module according to the synchronization control signal and the image stream, so as to control the backlight module to sequentially transmit the reference voltage to each One row of scan lines makes the backlight module emit light in a row scan manner. The driving module also generates an image update signal according to the synchronization control signal and the switching signal corresponding to the scan line of the last row, and the image update signal is related to the image update of the display module.

Therefore, the second object of the present invention is to provide a driving method for a scanning display, which is executed by a driving module. The scanning display includes a backlight module that receives a reference voltage and includes a common cathode. Architecture of the light-emitting diode array.

Therefore, the driving method of the scanning display includes the following steps: (A) receiving and temporarily storing an image stream from a control module. (B) Receive a synchronous control signal from the control module. (C) According to the synchronization control signal, the image stream, and a clock signal related to the scan switching of the scanning display, a plurality of switching signals corresponding to a plurality of scan lines are generated to the backlight module to The backlight module is controlled to transmit the reference voltage to the scan lines of each row, so that the backlight module emits light in a row scan manner. (D) According to the synchronization control signal and the reference voltage output to the scan line of the last row, an image update signal is generated, and the image update signal is related to the image update of the scanning display.

The third objective of the present invention is to provide a scanning display that emits direct display without liquid crystal display.

Therefore, the scanning display includes a light emitting diode direct display module and a driving device.

The light-emitting diode direct display module receives a reference voltage and includes a plurality of scan lines arranged in a row direction with each other, a plurality of data lines arranged in a row direction with each other perpendicular to the scan lines, and a plurality of data lines arranged in correspondence with each other. The light-emitting diodes between the matrixes defined by the multiple scan lines and the multiple data lines, each light-emitting diode has an electrical connection corresponding to the cathode of the scan line, and an electrical connection corresponding to the The anode of the data line. The driving device includes a control module and a driving module.

The control module generates an image stream and a synchronization control signal. The driving module is electrically connected to the light emitting diode direct display module, and is electrically connected to the control module to receive the synchronization control signal and the image stream. The driving module is based on the synchronization control signal and the image stream , Output a plurality of switching signals corresponding to a plurality of scan lines to the backlight module to control the light-emitting diode direct display module to transmit the reference voltage to the scan lines of each row, so that the light-emitting diode is directly The display module emits light in a row scanning manner, and the driving module also generates an image update signal according to the synchronization control signal and the reference voltage output to the scan line of the last row, and according to the image update signal and the image Streaming generates a plurality of driving signals to the plurality of data lines of the light emitting diode direct display module.

The effect of the present invention is that the circuit structure used to drive the light-emitting diode (LED) array of the common cathode structure not only saves the overall power consumption of the LED display and greatly reduces the heat dissipation of the system, but also performs processing based on the image update signal. The image display and update can prevent the screen displayed by the display module from being suddenly cut off due to the synchronization control signal, and the display module will not have image tearing or interruption.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same numbers.

Referring to FIGS. 1 and 2, an embodiment of the scanning display of the present invention is suitable for image display. The scanning display (eg, a liquid crystal display) supports a dynamic frame rate and includes a backlight module 11, a display module 12 (eg, a liquid crystal display panel) for displaying images, and a Drive 2.

The backlight module 11 receives a reference voltage and includes a light-emitting diode array with a common cathode structure and a scanning unit. The reference voltage is a ground voltage (GND). The light emitting diode array includes a plurality of scan lines arranged in a row direction with each other, a plurality of data lines arranged perpendicular to the scan lines in a row direction with each other, and a plurality of light emitting diodes 116. A plurality of light-emitting diodes 116 are respectively arranged in a matrix defined by the plurality of scan lines and the plurality of data lines, and each light-emitting diode 116 has a cathode electrically connected to the corresponding scan line. And an electrical connection corresponding to the anode of the data line.

The scanning unit SU receives a plurality of switching signals SW1 to SW3 and the reference voltage and is electrically connected to each scan line of the backlight module 11, and is controlled by the plurality of switching signals SW1 to SW3 to sequentially output the reference voltage to the The scan line of each row of the backlight module 11. The scan unit SU includes a plurality of scan switches S1 to S3 corresponding to a plurality of scan lines, and each scan switch has a first end that receives the reference voltage and a second end that is electrically connected to the scan line. And a control terminal that receives the corresponding switching signal is switched between conducting and non-conducting according to the switching signal.

The driving device 2 includes a control module 21 and a driving module 22.

The control module 21 generates a synchronization control signal VSYNC, and an internal graphics processing unit (GPU, not shown) generates an image stream Dr with a plurality of image data Draw. The image stream Dr is related to the screen to be displayed by the display module 12. In this embodiment, the control module 21 sequentially outputs the image data as the image stream Dr.

The driving module 22 is used to electrically connect the backlight module 11 and the display module 12, and is electrically connected to the control module 21 to receive the synchronization control signal VSYNC and the image stream Dr, and drive the backlight accordingly Module 11 and the display module 12. The driving module 22 generates a plurality of switching signals corresponding to a plurality of scan lines to the backlight module 11 according to the synchronization control signal VSYNC and the image stream Dr, so as to control the backlight module 11 to use the reference voltage The scan line transmitted to each row causes the backlight module 11 to emit light in a row scan manner. The driving module 22 also generates an image update signal according to the synchronization control signal VSYNC and the switching signal corresponding to the scan line of the last row Draw_update, the image update signal Draw_update is related to the image update of the display module 12. The driving module 22 also generates an output signal to the display module 12 according to the image update signal and the image stream, so as to drive the display module 12 to perform image display and update, so that the display module 12 Following the change of the image update signal, the displayed image is updated.

In this embodiment, the driving module 22 includes a storage unit 221, a first driving signal generator 222, and a second driving signal generator 223.

The storage unit 221 is electrically connected to the control module 21 to receive and temporarily store the image stream Dr from the control module 21. And the storage unit 22 has two memories SRAMA and SRAMB for temporarily storing the image data Draw1 to Draw4 of the image stream Dr, that is, the image data temporarily stored by SRAMA and SRAMB are displayed in turn. It is further explained here that the first image data Draw1 is displayed after the first image update signal Draw_update, while the second image data Draw2 is temporarily stored in the memory SRAMB; the second image data Draw2 is displayed after the second Draw_update, At the same time, the third image data Draw3 is temporarily stored in the memory SRAMA; after the third Draw_update, the third image data Draw3 is displayed, and the fourth image data Draw4 is temporarily stored in the memory SRAMB... and so on.

The first driving signal generator 222 is electrically connected to the storage unit 221, the scanning unit SU, and the control module 21, and has a phase-locked loop circuit 224 that generates the clock signal. The first driving signal generator 222 receives the Synchronize the control signal VSYNC and the image stream Dr, and generate the plurality of switching signals SW1 to SW3 according to the synchronization control signal VSYNC, the image stream Dr, and the clock signal, and also generate the plurality of switching signals SW1 to SW3 according to the synchronization control signal VSYNC And corresponding to the switching signal SW3 of the scan line of the last row, the image update signal Draw_update is generated. And the image stream Dr temporarily stored in the storage unit 221 is sent to the first drive generator 222 to generate a plurality of drive signals D1 to D3 related to the image stream Dr. The second driving signal generator 223 is electrically connected to the first driving signal generator 222 to receive the image update signal Draw_update, and generates the output signal Do according to the image update signal Draw_update and the image stream Dr. It should be noted that the second driving signal generator 223 is a driving circuit including a source driver and a gate driver and is well known to those with ordinary knowledge in the art, so it will not be repeated here. And the second driving signal generator 223 generates an update signal to the first driving signal generator 222 according to the image update signal, so that the first driving signal generator 222 outputs the driving signals D1 to Dn to the backlight module The time point of the group is determined by the update signal from the second driving signal generator 223.

3, the driving module 22 executes a scanning display driving method to drive the scanning display for image display and updating. The driving method includes a step S, a step A, a step B, a step C, One step D, one step E.

In step S, the phase-locked loop circuit 224 of the driving signal generator 222 of the driving module 22 generates the clock signal.

In step A, the storage unit 221 of the driving module 22 receives the image stream Dr from the control module 21 and temporarily stores the image stream Dr.

In step B, the driving signal generator 222 of the driving module 22 receives the synchronization control signal VSYNC and the image stream Dr from the control module 21 and the storage unit 221, respectively.

In step C, the driving module 22 generates a plurality of switches corresponding to a plurality of scan lines according to the synchronization control signal VSYNC, the image stream Dr temporarily stored from the storage unit 221, and the clock signal. The signal is sent to the backlight module 11 to control the backlight module 11 to transmit the reference voltage to the scan lines of each row, and scan the backlight module 11 for rows. As shown in Fig. 4, this step C includes the following sub-steps 341 to 343.

In the sub-step C1, the driving signal generator 222 generates the switching signals SW1 to SW3 according to the synchronization control signal VSYNC and the clock signal. In this embodiment, each of the switching signals SW1 to SW3 is a pulse signal with multiple square waves, and its pulse width is an integer multiple of a period of the clock signal. In each row scanning period of the backlight module 11, the pulse waves of the switching signals SW1 to SW3 are interlaced. In addition, the first pulse of the synchronization control signal VSYNC triggers the switching of the switching signals SW1 to SW3.

In the sub-step C2, the driving signal generator 222 generates the driving signals D1 to Dn according to the image stream Dr and the clock signal. In this embodiment, each of the driving signals D1 to Dn is a pulse signal with multiple square waves, and its pulse width is an integer multiple of the period of the clock signal, and the The integer multiple varies with the image stream Dr.

In sub-step C3, the driving signal generator 222 outputs the switching signals SW1 to SW3 to the control terminals of the scan switches S1 to S3, respectively.

In step D, the driving signal generator 222 of the driving module 22 generates and outputs a signal according to the synchronization control signal VSYNC and the last switching signal among the switching signals SW1 to SW3 (ie, the switching signal SW3) The image update signal Draw_update is sent to the driving signal generator 223, and the image update signal Draw_update is related to the image update of the display module 12 of the scanning display 1.

In this embodiment, as shown in FIG. 2, the last switching signal SW3 corresponds to the last line of the line scan performed by the scanning display 1 when it emits light. The synchronization control signal VSYNC and the image update signal Draw_update are each a pulse signal with multiple square waves. The driving signal generator 222 generates the image update signal Draw_update in a manner such that each square wave of the image update signal Draw_update lags behind a corresponding square wave of the synchronization control signal VSYNC, and the image update signal Draw_update except A starting point of each square wave other than the first square wave occurs simultaneously with an end point of a square wave of the switching signal SW3 (ie, the last switching signal among the switching signals SW1 to SW3). The end point of the square wave of the switching signal SW3 appears immediately after the start point of the corresponding square wave of the synchronization control signal VSYNC.

In step E, the drive signal generator 223 of the drive module 22 generates and outputs an output signal Do to the scan according to the image update signal Draw_update and the image stream Dr temporarily stored in the storage unit 221 The display module 12 of the display 1 drives the display module 12 to display and update the image according to the output signal Do, so that the display module 12 updates the displayed image according to the change of the image update signal Draw_update image. To further illustrate, when the second driving signal generator 223 receives the image update signal Draw_update from the first driving signal generator 222, it further generates an update signal to the first driving signal generator 222, and the driving module The first driving signal generator 222 of 22 outputs the driving signals D1 to Dn to the cathodes of the corresponding light-emitting diodes 116 in the light-emitting diode array according to the update signal to drive the backlight module The LED array of 11 emits light row by row. It should be noted that each row in the light-emitting diode array of the backlight module 11 emits light from row by row is defined as each column (ie, each horizontal row) of the light-emitting diode 116 in the light-emitting diode array. .

It should be supplemented that, in this embodiment, step S is executed before step A, but it is not limited to this. In other embodiments, step S can also be executed between step A and step B, or between step B and step C.

As shown in FIG. 5, a second embodiment of the scanning display 1 of the present invention is a direct display without a liquid crystal display. The difference from the first embodiment is that there is no display module 12 like a liquid crystal display panel, but A light-emitting diode direct display module 10 is used to replace the backlight module 11 of the first embodiment; and in this embodiment, the driving module 22 outputs a plurality of respective The switching signals corresponding to multiple scan lines are sent to the LED direct display module 10 to control the LED direct display module 10 to transmit the reference voltage to the scan lines of each row, so that the LED The body direct display module 10 emits light in a line scanning manner. The driving module 22 also generates an image update signal Draw_update according to the synchronization control signal and the switching signal corresponding to the scan line of the last row, and generates a plurality of drives according to the image update signal Draw_update and the image stream Dr. Signals to the multiple data lines of the LED direct display module 10. Furthermore, the driving module 22 of the second embodiment does not include the second driving signal generator 223, but the first driving signal generator 223 internally generates the image update signal Draw_update, and decides to generate it according to the image update signal Draw_update. The driving signals D1~Dn reach the time point of the light emitting diode direct display module 10, that is, the first driving signal generator 222 is also based on the synchronization control signal and the switching signal corresponding to the last scan line , Generate an image update signal Draw_update, and generate a plurality of driving signals D1 to Dn to the plurality of data lines of the light emitting diode direct display module 10 according to the image update signal Draw_update and the image stream.

In summary, the above embodiment has the following advantages:

1. Since the red light diode does not require a higher driving voltage, the light emitting diode (LED) of the common cathode structure can save the overall power consumption of the LED display. 2. If the switching signals (SW1~SW3) for line scanning are output by the drive module 22, the complexity of the hardware design and software settings of the control module 21 can be greatly reduced.

3. Since the scanning unit SU and the driving module 22 are not integrated into a single chip, the design of the driving module 22 is more flexible, allowing users to more flexibly match the number of LEDs to be loaded; and The heat of the driving module 22 can be evenly distributed to the external scanning unit SU (line scan MOS), so that the temperature will not be concentrated on the same chip, which greatly reduces the trouble of system heat dissipation.

4. The driving method is to make the display module 12 update the displayed image according to the change of the image update signal Draw_update, that is, the image displayed by the display module 12 will be displayed on the backlight module 11 Only after the corresponding last line scan ends (that is, an end point corresponding to one of the square waves of the switching signal SW3) will the displayed screen be updated, and then the display module 12 is displaying The image of, due to the synchronization control signal VSYNC, will not be updated before the line scan corresponding to the backlight module 11 is completed, so that the displayed image can be prevented from being suddenly cut off and causing image tearing or interruption. The driving method of the present invention has a better picture display than the driving method of the existing display (which performs image display and update according to the synchronization control signal VSYNC, which causes the picture to be torn or interrupted).

However, the above are only examples of the present invention. When the scope of implementation of the present invention cannot be limited by this, all simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the content of the patent specification still belong to Within the scope covered by the patent of the present invention.

10: LED direct display module 11: Backlight module SU: Scanning unit S1~S3: Scan switch 116: LED 12: Display module 2: drive device 21: Control module 22: drive module 221: storage unit 222: The first drive signal generator 223: second drive signal generator 224: Phase Locked Loop Circuit S~E: Step C1~C3: sub-step D1~Dn: drive signal Do: output signal Dr: image streaming Draw1~4: image data SW1~SW3: switching signal t: time Draw_update: image update signal VSYNC: synchronization control signal

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: Fig. 1 is a circuit diagram of a first embodiment of a scanning display of the present invention; Figure 2 is a timing diagram of the first embodiment; 3 is a flowchart of a driving method of a scanning display executed by a driving module of the first embodiment; FIG. 4 is a flow chart of the backlight module emitting light in a row scanning manner in the driving method; and Fig. 5 is a circuit diagram of a second embodiment of the scanning display of the present invention.

11: Backlight module

SU: Scanning unit

S1~S3: Scan switch

116: LED

12: Display module

2: drive device

21: Control module

22: drive module

221: storage unit

222: The first drive signal generator

223: second drive signal generator

224: Phase Locked Loop Circuit

Claims (10)

A scanning display, including: A backlight module that receives a reference voltage and includes a light-emitting diode array with a common cathode structure, the light-emitting diode array including: Multiple scan lines are arranged along one line with each other, A plurality of data lines are arranged perpendicularly to the scan lines along a row of each other, A plurality of light-emitting diodes are respectively correspondingly arranged between the matrix defined by the plurality of scan lines and the plurality of data lines, each light-emitting diode has a cathode electrically connected to the corresponding scan line, and An electrical connection corresponding to the anode of the data line; A display module for displaying images; A driving device, including: A control module to generate an image stream and a synchronization control signal; and A driving module electrically connected to the backlight module and the display module, and electrically connected to the control module to receive the synchronization control signal and the image stream, The driving module generates a plurality of switching signals corresponding to a plurality of scanning lines to the backlight module according to the synchronization control signal and the image stream, so as to control the backlight module to transmit the reference voltage to each row Scan line, The driving module also generates an image update signal according to the synchronization control signal and the switching signal corresponding to the scan line of the last row, and the image update signal is related to the image update of the display module. The scanning display according to claim 1, wherein the driving module further generates an output signal to the display module according to the image update signal and the image stream, so as to drive the display module to perform image Display and update, so that the display module updates the displayed image following the change of the image update signal. The scanning display according to claim 1, wherein the backlight module includes: A scanning unit receives a plurality of switching signals and the reference voltage and is electrically connected to each scan line of the backlight module, and is controlled by the plurality of switching signals to sequentially output the reference voltage to each row of the backlight module Scan line. The scanning display according to claim 3, wherein the driving module includes: A first drive signal generator is electrically connected to the scanning unit and the control module, and has a phase-locked loop circuit that generates the clock signal. The first drive signal generator receives the synchronization control signal and the image string According to the synchronization control signal, the image stream and the clock signal, the multiple switching signals are generated, and the image update is also generated according to the synchronization control signal and the switching signal corresponding to the last scan line Signal, and A second driving signal generator is electrically connected to the first driving signal generator to receive the image update signal, and generates the output signal according to the image update signal and the image stream. The scanning display according to claim 3, wherein the scanning unit includes a plurality of scanning switches corresponding to a plurality of scanning lines, and each scanning switch has a first terminal receiving the reference voltage and an electrical connection corresponding to The second end of the scan line and a control end that receives the corresponding switching signal are switched between conducting and non-conducting according to the switching signal. A driving method of a scanning display is executed by a driving module. The scanning display includes a backlight module. The backlight module receives a reference voltage and includes a light-emitting diode array with a common cathode structure. The scanning display The driving method includes the following steps: (A) Receive and temporarily store an image stream from a control module; (B) Receive a synchronous control signal from the control module; (C) According to the synchronization control signal, the image stream, and a clock signal related to the scan switching of the scanning display, a plurality of switching signals corresponding to a plurality of scan lines are generated to the backlight module to Controlling the backlight module to transmit the reference voltage to the scan line of each row; and (D) According to the synchronization control signal and the switching signal corresponding to the scan line of the last row, an image update signal is generated, and the image update signal is related to the image update of the scanning display. The driving method according to claim 6, wherein after step (D), the method further includes step (E) according to the image update signal and the image stream, generating an output signal to the scanning display to drive The scanning display performs image display and update, so that the scanning display updates the displayed image following the change of the image update signal. A scanning display, including: A light-emitting diode direct display module that receives a reference voltage and includes a light-emitting diode array with a common cathode structure, the light-emitting diode array including Multiple scan lines are arranged along one line with each other, A plurality of data lines are arranged perpendicularly to the scan lines along a row of each other, A plurality of light-emitting diodes are respectively correspondingly arranged between the matrix defined by the plurality of scan lines and the plurality of data lines, each light-emitting diode has a cathode electrically connected to the corresponding scan line, and An electrical connection corresponding to the anode of the data line; A driving device, including: A control module to generate an image stream and a synchronization control signal; A driving module, electrically connected to the light emitting diode direct display module, and electrically connected to the control module to receive the synchronization control signal and the image stream, The driving module outputs a plurality of switching signals corresponding to a plurality of scan lines to the direct display module of the light emitting diode according to the synchronization control signal and the image stream, so as to control the direct display module of the light emitting diode The group transmits the reference voltage to the scan line of each row, The driving module also generates an image update signal according to the synchronization control signal and the switching signal corresponding to the scan line of the last row, and generates a plurality of driving signals to the light emitting device according to the image update signal and the image stream. The multiple data lines of the diode direct display module. The scanning display according to claim 8, wherein the light-emitting diode direct display module includes: A scanning unit receives a plurality of switching signals and the reference voltage and is electrically connected to each scan line of the light-emitting diode array, and is controlled by the plurality of switching signals to sequentially output the reference voltage to the light-emitting diode Scan lines for each row of the array. The scanning display according to claim 8, wherein the driving module includes: A storage unit electrically connected to the control module to temporarily store the image stream; and A first drive signal generator is electrically connected to the light emitting diode direct display module and the control module, and has a phase-locked loop circuit that generates a clock signal. The first drive signal generator receives from the control module Set the synchronization control signal and the image stream from the storage unit, and generate the plurality of switching signals according to the synchronization control signal, the image stream, and the clock signal, and also generate the plurality of switching signals according to the synchronization control signal And corresponding to the switching signal of the scan line of the last row, the image update signal is generated.

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