TWI768708B - Scanning display and driving method thereof - Google Patents

Abstract

A scanning display includes a backlight module with a common cathode structure, a display module, a control module and a driving module. The backlight module includes a plurality of scanning lines and a plurality of data lines respectively correspondingly disposed A plurality of light emitting diodes between the defined matrices. The control module generates an image stream and a synchronization control signal. The driving module is electrically connected to the control module to receive the synchronization control signal and the image stream, and the drive module generates a plurality of switches corresponding to the plurality of scan lines according to the synchronization control signal and the image stream. signal to the backlight module to control the backlight module to transmit the reference voltage to the scan lines of each row, the driving module also generates a graph according to the synchronization control signal and the switching signal corresponding to the scan line of the last row Like the update signal, the image update signal is related to the image update of the display module.

Description

Scanning display and driving method thereof

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.

A conventional driving device for driving a scanning display to display images includes a control module and a driving module. The driving module receives a synchronization control signal related to image display and updating 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 picture to be displayed by 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 performs image display and update of 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 periodically updates the displayed picture. a screen frame rate and the synchronization control signal the same frequency.

However, when the synchronization control signal is an aperiodic signal, and the backlight module is a scanning backlight module that is triggered by the synchronization control signal and adopts scanning control to emit light row by row in sequence, the above-mentioned conventional scanning display The driving method may cause tearing or interruption of the picture displayed by the display module. Therefore, there is still room for improvement in the driving method of the existing scanning display.

Therefore, a first objective of the present invention is to provide a scanning display that can avoid tearing or interruption of the picture displayed by 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 scanning lines arranged along a row direction with each other, a plurality of scanning lines arranged perpendicular to each other along a column direction data lines of the line, a plurality of light-emitting diodes respectively disposed between the plurality of scan lines and the matrix defined by the plurality of data lines, and each light-emitting diode has an electrical connection corresponding to the scan line The cathode of the wire, and the anode of the data wire 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 The control module receives the synchronization control signal and the image stream. The driving module generates a plurality of switching signals corresponding to the 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 A 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 performed by a driving module, and the scanning display includes a backlight module that receives a reference voltage and includes a common cathode. Architecture of light-emitting diode arrays.

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 synchronization control signal from the control module. (C) generating a plurality of switching signals corresponding to a plurality of scanning lines to the backlight module according to the synchronization control signal, the image stream and a clock signal related to the scanning switching of the scanning display, so as 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 scanning 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 object of the present invention is to provide a scanning display that emits light directly without liquid crystal display.

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

The LED direct display module receives a reference voltage and includes a plurality of scan lines arranged along a row direction with each other, a plurality of data lines arranged perpendicular to the scan lines along a column direction, a plurality of data lines arranged correspondingly to each other on the scan lines The light-emitting diodes between the matrixes defined by the plurality of scan lines and the plurality of 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 LED direct display module, and is electrically connected to the control module to receive the synchronization control signal and the image stream. The drive module is based on the synchronization control signal and the image stream. , output a plurality of switching signals corresponding to the plurality of scanning lines to the backlight module, so as to control the LED direct display module to transmit the reference voltage to the scanning lines of each row, so that the LEDs are 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 The serial stream generates a plurality of driving signals to the plurality of data lines of the LED direct display module.

The effect of the present invention is: used to drive the light emitting diode of the common cathode structure The circuit structure of the (LED) array not only saves the overall power consumption of the LED display and greatly reduces the trouble of system heat dissipation, but also can avoid the image displayed by the display module by performing image display and update according to the image update signal. The synchronization control signal is suddenly cut off, so that the display module will not have image tearing or interruption.

10: LED direct display module

11: Backlight module

SU: Scanning Unit

S1~S3: Scan switch

116: Light Emitting Diode

12: Display module

2: drive unit

21: Control module

22: Driver module

221: storage unit

222: first drive signal generator

223: second drive signal generator

224: Phase Locked Loop Circuit

S~E: Steps

C1~C3: Substeps

D1~Dn: drive signal

Do: output signal

Dr: Image Streaming

Draw1~4: Image data

SW1~SW3: switch 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, wherein: FIG. 1 is a circuit diagram of a first embodiment of a scanning display of the present invention; FIG. 2 is the first embodiment Fig. 3 is the flow chart of the driving method of a scanning-type display performed by a driving module of the first embodiment; Fig. 4 is the flow chart of the driving method emitting light in a row scanning manner to the backlight module 5 is a circuit diagram of a second embodiment of a scanning display of the present invention.

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

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, and the reference voltage is a ground voltage (GND). The light emitting diode array includes: a plurality of scan lines arranged along a row direction with each other, a plurality of data lines arranged perpendicular to the scan lines along a column direction with each other, and a plurality of light emitting diodes 116 . A plurality of light emitting diodes 116 are respectively disposed between the 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 anode electrically connected to the corresponding data line.

The scanning unit SU receives a plurality of switching signals SW1 ˜ SW3 and the reference voltage, is electrically connected to each scanning line of the backlight module 11 , and is controlled by the plurality of switching signals SW1 ˜ SW3 to sequentially output the reference voltage to the Scan lines of each row of the backlight module 11 . The scan unit SU includes a plurality of scan switches S1-S3 corresponding to the plurality of scan lines, each scan switch has a first end for receiving the reference voltage, and a second end electrically connected to the corresponding scan line, and a control terminal that receives the corresponding switching signal, and switches 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 its internal A graphics processing unit (GPU, not shown) of the device generates an image stream Dr with a plurality of image data Draw. The image stream Dr is related to the picture 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 to drive the backlight accordingly The module 11 and the display module 12 . The driving module 22 generates a plurality of switching signals corresponding to the 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 the reference voltage It is transmitted to the scan lines of each row, so that the backlight module 11 emits light in a row scanning manner, and the driving module 22 also generates an image update signal according to the synchronization control signal VSYNC and the switching signal of the scan line corresponding to 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 to drive the display module 12 to perform image display and update, so that the display module 12 The displayed image is updated following the change of the image update signal.

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 data from The image stream Dr of the control module 21 . 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 in SRAMA and SRAMB are displayed in turn. It is further described 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; the third image data Draw3 is displayed after the third Draw_update, 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 for generating the clock signal, and the first driving signal generator 222 receives the Synchronizing the control signal VSYNC and the image stream Dr, and generating 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 according to the synchronization control signal VSYNC And corresponding to the switching signal SW3 of the last row of scanning lines, 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 driving generator 222 for generating a plurality of driving 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 generate the output signal Do according to the image update signal Draw_update and the image stream Dr. need 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 skilled in the art, so it will not be repeated here. And the second drive signal generator 223 generates an update signal to the first drive signal generator 222 according to the image update signal, so that the first drive signal generator 222 outputs the drive 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 .

Referring to FIG. 3 , the driving module 22 executes a driving method of a scanning display to drive the scanning display to perform image display and update. The driving method includes a step S, a step A, a step B, a step C, a 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 scanning lines according to the synchronization control signal VSYNC, the image stream Dr temporarily stored from the storage unit 221, and the clock signal signal to the backlight module 11 to control the backlight module 11 to transmit the reference voltage to the scan lines of each row, to the back The optical module scans in 11 lines. As shown in FIG. 4 , this step C includes the following sub-steps 341 to 343 .

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

In sub-step C2, the driving signal generator 222 generates the driving signals D1-Dn according to the image stream Dr and the clock signal. In this embodiment, each of the driving signals D1 ˜Dn is a pulse wave signal having a plurality of square waves, and the pulse wave width thereof 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-SW3 to the control terminals of the scan switches S1-S3, respectively.

In step D, the driving signal generator 222 of the driving module 22 generates and outputs a switching signal (ie, the switching signal SW3 ) according to the synchronization control signal VSYNC and the last switching signal (ie, the switching signal SW3 ) among the switching signals SW1 ˜ 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 . new.

In this embodiment, as shown in FIG. 2 , the last switching signal SW3 corresponds to the last line of the line scanning performed by the scanning display 1 when emitting light. Each of the synchronization control signal VSYNC and the image update signal Draw_update is a pulse wave signal with a plurality of square waves. The driving signal generator 222 generates the image update signal Draw_update in such a way that each square wave of the image update signal Draw_update lags a corresponding square wave of the synchronization control signal VSYNC, and the image update signal Draw_update is excepted A start point of each square wave other than the first square wave coincides with an end point of the square wave of the switching signal SW3 (ie, the last switching signal of the switching signals SW1 ˜ SW3 ). The end point of the square wave of the switching signal SW3 occurs immediately after a 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 type display 1 to drive the display module 12 to perform image display and update according to the output signal Do, so that the display module 12 follows the change of the image update signal Draw_update to update the displayed image 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, the first driving signal generator 222 of the driving module 22 outputs the driving signals D1-Dn to the cathodes of the plurality of LEDs 116 corresponding to each in the LED array according to the update signal, The light-emitting diode array driving the backlight module 11 emits light row by row. It should be noted that each row of the light-emitting diode array of the backlight module 11 is defined as each column (ie, each horizontal row) of the light-emitting diodes 116 in the light-emitting diode array. .

It should be added that, in this embodiment, step S is performed before step A, but it is not limited to this. In other embodiments, step S may also be performed between step A and step B, or performed 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 liquid crystal display. The difference from the first embodiment is that there is no display module 12 like a liquid crystal display panel, but The backlight module 11 of the first embodiment is replaced by a light-emitting diode direct display module 10; and in this embodiment, the driving module 22 outputs a plurality of respectively according to the synchronization control signal and the image stream The switching signals corresponding to the plurality of 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 volume 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 drivers according to the image update signal Draw_update and the image stream Dr Signal to the plurality of data of the LED direct display module 10 Wire. Further, 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 time points from the driving signals D1 to Dn to the LED direct display module 10 , that is to say, the first driving signal generator 222 is also based on the synchronization control signal and the switching signal corresponding to the last row of scan lines. , an image update signal Draw_update is generated, and a plurality of driving signals D1 to Dn are generated to the data lines of the LED direct display module 10 according to the image update signal Draw_update and the image stream.

To sum up, the above embodiments have the following advantages:

1. Since the red light diode does not need 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 ) used for line scanning are output by the driving module 22 , the complexity of the hardware design and software setting 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 different LED loading points; 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.

Fourth, 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 display module 12 The picture displayed in the group 12 will not be updated until the last line corresponding to the backlight module 11 is finished (ie, corresponding to an end point of a corresponding one of the square waves of the switching signal SW3). The displayed picture, and thus the picture displayed by the display module 12 will not be updated when the line scan corresponding to the backlight module 11 is not completed due to the synchronization control signal VSYNC, so that the displayed picture can be avoided. The image is suddenly cut off and the image is torn or interrupted, so that the driving method of the present invention is compared with the driving method of the existing display (which causes the image to be displayed and updated according to the synchronization control signal VSYNC, which causes the image to tear or be interrupted) , with better picture display.

However, the above are only examples of the present invention, and should not limit the scope of implementation of the present invention. Any simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the contents of the patent specification are still included in the scope of the present invention. within the scope of the invention patent.

11: Backlight module

SU: Scanning Unit

S1~S3: Scan switch

116: Light Emitting Diode

12: Display module

2: drive unit

21: Control module

22: Driver module

221: storage unit

222: first drive signal generator

223: second drive signal generator

224: Phase Locked Loop Circuit

Claims (10)

A scanning type display includes: a backlight module, receiving a reference voltage and including a light-emitting diode array with a common cathode structure, the light-emitting diode array includes: a plurality of scanning lines, arranged along a row direction with each other, a plurality of data Lines are arranged perpendicular to the scan lines along a column direction, 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 It has a cathode electrically connected to the corresponding scanning line, and an anode electrically connected to the corresponding data line; a display module for displaying images; a driving device including: a control module for generating a an image stream, and a synchronization control signal; and a drive 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 The driving module generates a plurality of switching signals corresponding to the 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 the scanning of each line line, the driving module also generates an image update signal according to the synchronization control signal and the switching signal corresponding to the scanning line of the last row, the The image update signal is related to the image update of the display module. The scanning display of 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 images Display and update, so that the display module updates the displayed image following the change of the image update signal. The scanning display of claim 1, wherein the backlight module comprises: a scanning unit that receives a plurality of switching signals and the reference voltage and is electrically connected to each scanning line of the backlight module, and receives the plurality of switching signals and the reference voltage. The switching signal is controlled to sequentially output the reference voltage to the scan lines of each row of the backlight module. The scanning display of claim 3, wherein the driving module comprises: a first driving signal generator, which is electrically connected to the scanning unit and the control module, and has a phase-locked loop circuit that generates a clock signal, The first driving signal generator receives the synchronization control signal and the image stream, and generates the plurality of switching signals according to the synchronization control signal, the image stream and the clock signal, and also controls the synchronization according to the synchronization control signal. signal and the switching signal corresponding to the scan line of the last row to generate the image update signal, and a second drive signal generator electrically connected to the first drive signal generator to receive the image update signal and to generate the image update signal according to the image The update signal and the image stream generate an output signal. The scanning display according to claim 3, wherein the scanning unit comprises a plurality of scanning switches corresponding to the plurality of scanning lines, and each scanning switch It has a first end that receives the reference voltage, a second end that is electrically connected to the corresponding scan line, and a control end that receives the corresponding switching signal, and switches between conducting and non-conducting according to the switching signal . A driving method of a scanning display is performed 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 comprises the following steps: (A) receiving and temporarily storing an image stream from a control module; (B) receiving a synchronization control signal from the control module; (C) according to the synchronization control signal, The image stream and a clock signal related to the line-scan switching of the scanning display generate a plurality of switching signals corresponding to a plurality of scanning lines to the backlight module, so as to control the backlight module to the reference voltage transmitting to the scan lines of each row; and (D) generating an image update signal according to the synchronization control signal and the switching signal corresponding to the scan line of the last row, the image update signal being related to the image of the scanning display renew. The driving method of claim 6, wherein after step (D), further comprising step (E) generating an output signal to the scanning display according to the image update signal and the image stream to drive the scanning display 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 type display, comprising: a light-emitting diode direct display module, receiving a reference voltage and including a common-cathode structure light-emitting diode array, the light-emitting diode array includes A plurality of scan lines are arranged along a row direction with each other, a plurality of data lines are arranged perpendicular to each other along a column direction on the scan lines, and a plurality of light emitting diodes are respectively arranged correspondingly between the plurality of scan lines and the plurality of scan lines. Between the matrixes defined by the data lines, each light-emitting diode has a cathode electrically connected to the corresponding scan line, and an anode electrically connected to the corresponding data line; a driving device includes: a control module , generates an image stream and a synchronization control signal; a drive module is electrically connected to the LED direct display module, and is 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 the plurality of scan lines to the LED direct display module according to the synchronization control signal and the image stream, so as to control the LED direct display The module transmits the reference voltage to the scan lines of each row, and 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 according to the image update signal A plurality of driving signals are generated to the plurality of data lines of the LED direct display module with the image stream. The scanning display according to claim 8, wherein the LED direct display module comprises: a scanning unit that receives a plurality of switching signals and the reference voltage and electrically Each scan line of the light emitting diode array is connected and controlled by the plurality of switching signals to sequentially output the reference voltage to the scan lines of each row of the light emitting diode array. The scanning display of claim 8, wherein the driving module comprises: a storage unit electrically connected to the control module to temporarily store the image stream; and a first driving signal generator electrically connected to the The LED direct display module and the control module have a phase-locked loop circuit that generates a clock signal, and the first driving signal generator receives the synchronous control signal from the control module and from the storage unit the image stream, and generate a plurality of switching signals according to the synchronization control signal, the image stream and the clock signal, and also generate a plurality of switching signals according to the synchronization control signal and the switching signal corresponding to the last row of scan lines The image update signal.

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