TWI750031B - Scanning display and its driving device and driving method - 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. Multiple light-emitting diodes between the defined matrix. The control 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 to control the backlight module to transmit the reference voltage to the scan lines of each row The control module further 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.

Description

Scanning display and its driving device and driving method

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

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 screen frame rate (frame rate) and the synchronization control signal The frequency is the same.

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 is controlled by scanning to sequentially emit light row by row, the above-mentioned 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, and according to the synchronization control signal and the image stream, generates a plurality of switching signals corresponding to a plurality of scan lines to the backlight module to control The backlight module transmits the reference voltage to the scan line of each row, so that the backlight module emits light in a row scan manner, and the control module also generates the switching signal according to the synchronization control signal and the switching signal corresponding to the scan line of the last row An image update signal, the image update signal is related to the image update of the display module.

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. And the image update signal, the driving module also 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 The display module updates the displayed image following the change of the image update signal.

The second object 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, and according to The synchronization control signal and the image stream generate a plurality of switching signals corresponding to a plurality of scan lines to the backlight module, so as to control the backlight module to transmit the reference voltage to the scan lines of each row to the backlight module. Module line scanning, the control 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.

The drive 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 drive module is connected to the image stream according to the image update signal. The flow generates a plurality of driving signals to the plurality of data lines of the light-emitting diode direct display module.

The third object of the present invention is to provide a scanning display which includes a display module, a backlight module and a driving device, and the backlight module includes a plurality of scan lines and a plurality of A data line and a plurality of light-emitting diodes, each light-emitting diode having a cathode that is electrically connected to the scan line and an anode that is electrically connected to the data line. The driving method includes the following steps:( S) Use the backlight module to receive a ground voltage. (C) Using the driving device to generate a plurality of switching signals corresponding to a plurality of scanning lines to the backlight module according to a synchronization control signal and an image stream, so as to control the backlight module to transmit the ground voltage to each row Scan line. (D) Using the driving device to generate 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 update of the scanning display. (E) Use the driving device to update according to the image Signal and the image stream to generate an output signal to the display module to drive the display module to display and update the image, so that the display module updates the display module following the change of the image update signal image.

The effect of the present invention is that the circuit structure used to drive the 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 simplifies the digital timing of the drive module Design, and by performing image display and update according to the image update signal, the screen displayed by the display module can be prevented from being cut off suddenly due to the synchronization control signal, and the display module will not have image tearing or tearing. The interruption occurs.

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

Draw: image data

Draw1~Draw4: 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; FIG. 2 is the first embodiment Fig. 3 is a flow chart of a driving method of a scanning display executed by a driving module of the first embodiment; Fig. 4 is a flow chart of a driving method of the backlight module emitting light in a row scanning manner ;and Fig. 5 is a circuit diagram of a second embodiment of the 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 denoted by the same numbers.

Referring to Figures 1 and 2, an embodiment of the scanning display of the present invention is suitable for image display. The scanning display (e.g., a liquid crystal display) supports a dynamic frame rate and includes a backlight module 11, a display module 12 (e.g., a liquid crystal display panel) for displaying images, and a Drive device 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 SU. 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 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 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 lines of each row of the backlight module 11. The scanning unit SU includes multiple scanning lines corresponding to multiple scanning lines. Scan switches S1~S3. Each scan switch has a first terminal that receives the reference voltage, a second terminal that is electrically connected to the scan line, and a control terminal that receives the corresponding switching signal. Switch the signal to switch between conduction and non-conduction.

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, and according to a synchronization control signal VSYNC, the image stream Dr generates a plurality of corresponding to the plurality of The scanning line switching signals SW1~SW3 are sent to the backlight module 11 to control the backlight module 11 to transmit the reference voltage to the scanning lines of each row, so that the backlight module 16 emits light in a row scanning manner, and the control module 21 also generates an image update signal Draw_update according to the synchronization control signal VSYNC and the switching signal SW3 corresponding to the scan line of the last row. The image update signal Draw_update is related to the image update of the display module 12.

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, the image stream Dr and the image update signal Draw_update , And drive the backlight module 11 and the display module 12 accordingly. The driving module 22 also generates an output signal Do to the display module according to the image update signal Draw_update and the image stream Dr. 12. To drive the display module 12 to perform image display and update, so that the display module 12 updates the displayed image following the change of the image update signal Draw_update.

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 first driving signal generator 222 has a phase-locked loop circuit that generates the clock signal. The first driving signal generator 222 is electrically connected to the data lines of the backlight module 16, the control module 21 and the storage The unit 221 receives the image update signal Draw_update from the control module 21, the image stream from the storage unit 221, and generates a plurality of driving signals according to the image update signal Draw_update and the image stream D1~D3 to the multiple data lines of the LED array, and also generate an update signal according to the image update signal. The second driving signal generator 223 is electrically connected to the first driving signal generator 222 to receive the update signal, and generates the output signal Do according to the update signal 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.

The storage unit 221 is electrically connected to the control module 21 and the first and second drive signal generators 222 and 223, and receives and temporarily stores 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~Draw4 of the image stream Dr, that is, SRAMA, The image data temporarily stored in SRAMB are displayed in turn. Here is a further explanation. After the first Draw_update, the image data Draw1 is displayed, and the image data Draw2 is temporarily stored in the memory SRAMB; after the second Draw_update, the image data Draw2 is displayed, and the image data Draw3 is temporarily stored in the memory. SRAMA: After the third Draw_update, the image data Draw3 is displayed, and the image data Draw4 is temporarily stored in the memory SRAMB; and so on.

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, and uses the backlight module to receive a ground voltage.

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

In step C, the control module 2 generates a plurality of switching signals corresponding to a plurality of scan lines to the backlight module 11 to control the backlight module 11 to transmit the ground voltage to the scan lines of each row, so that the The backlight module 11 emits light in a line scanning manner. like As shown in FIG. 4, this step C includes the following sub-steps 341 to 343.

In the sub-step C1, the control module 2 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 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 control module 2 outputs the switching signals SW1 to SW3 to the control terminals of the scan switches S1 to S3, respectively.

In step D, the control module 2 generates and outputs an image update signal Draw_update to the synchronization control signal VSYNC and the last switching signal of the switching signals SW1~SW3 (ie, the switching signal SW3) The signal generator 222 is driven, 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. Each square wave of the image update signal Draw_update lags behind one of the corresponding square waves of the synchronization control signal VSYNC, and a starting point of each square wave except the first square wave in the image update signal Draw_update and the switching signal SW3 ( That is, one end point of the square wave of the last switching signal among the switching signals SW1 to SW3 occurs at the same time. 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 first drive signal generator 222 of the drive module 22 further generates an update signal to the second drive signal generator 223 according to the image update signal Draw_update, and the first drive of the drive module 22 The signal generator 222 outputs the driving signals D1 to Dn to the cathodes of the plurality of light emitting diodes 116 corresponding to each of the light emitting diode arrays according to the image update signal Draw_update to drive the backlight module 11 The light-emitting diode array 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 in the light-emitting diode array (ie, Each horizontal row) light-emitting diode 116. The driving signal generator 223 of the driving module 22 generates and outputs an output signal Do to the scan according to the update signal and the image stream Dr temporarily stored in the storage unit 221 The display module 12 of the type display 1 drives the display module 12 to perform image display and update 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.

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 liquid crystal display. The difference from the first embodiment is that there is no display module like a liquid crystal display panel, but with A light emitting diode direct display module 10 replaces the backlight module 11 of the first embodiment; and the driving module of the second embodiment does not include the second driving signal generator 223, but the first driving signal generator 223 is based on The image update signal Draw_update from the control module 21 determines the time point at which the driving signals D1 to Dn are output to the light emitting diode direct display module 10.

In summary, the foregoing 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) are output by the control module 21, the digital timing design of the drive module 22 can be simplified, and the number of pins used for transmission with the external switches S1~S3 can be reduced.

3. Because the scanning unit SU and the drive module 22 are not integrated in the manufacturing process On a single chip, the design of the drive module 22 is more flexible, allowing users to more flexibly match the number of LEDs to be loaded; and it can evenly distribute the heat of the drive module 22 to the external scanning unit (line scan) MOS), so that the temperature will not be concentrated on the same drive chip, greatly reducing 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 (ie, an end point corresponding to one of the square waves of the switching signal SW3) will the displayed screen be updated, and 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 it can prevent the displayed image from being suddenly cut off and causing image tearing or interruption. The driving method of the scanning display of the present invention has a better picture display than the driving method of the existing display (which causes picture tearing or interruption due to image display and update according to the synchronization control signal VSYNC).

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.

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 includes: 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 includes: a plurality of scan lines arranged in a row direction with each other, and a plurality of data The lines are arranged perpendicularly to the scan lines along a column direction. A plurality of light-emitting diodes are respectively arranged in a matrix defined by the plurality of scan lines and the plurality of data lines. Each light-emitting diode There is a cathode of the scan line corresponding to the electrical connection, and an anode of the data line corresponding to the electrical connection; a display module for displaying images; a driving device including: a control module for generating a Image stream, and a synchronization control signal, and according to the synchronization control signal and the image stream, a plurality of switching signals corresponding to a plurality of scan lines are generated to the backlight module to control the backlight module to The reference voltage is transmitted to the scan line of each row, the control 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 display module 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 and the image update signal, the The drive module also updates the signal according to the image and the image string Stream, generate an output signal to the display module 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 driving module includes: a storage unit electrically connected to the control module to receive the image stream, and temporarily store the image stream, a first driver The signal generator is electrically connected to the data lines of the backlight module, the control module and the storage unit to receive the image update signal from the control module and the image stream from the storage unit , And generate a plurality of driving signals to the plurality of data lines of the light-emitting diode array according to the image update signal and the image stream, and also generate an update signal according to the image update signal, and a second A driving signal generator is electrically connected to the first driving signal generator to receive the update signal, and generates the output signal according to the update signal and the image stream. The scanning display according to claim 2, wherein the first driving signal generator has a phase-locked loop circuit that generates a clock signal. The scanning display according to claim 1, wherein the backlight module includes: a scanning unit that receives a plurality of switching signals and the reference voltage and is electrically connected to each scan line of the backlight module, and is affected by 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. A driving device is suitable for electrically connecting a backlight module and a display module. The backlight module receives a ground voltage and includes a plurality of scan lines, a plurality of A data line and a plurality of light-emitting diodes, each light-emitting diode has a cathode electrically connected to the scan line and an anode electrically connected to the data line. The driving device includes: a control The module generates an image stream and a synchronization control signal, and 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 to control the backlight module The backlight module transmits the ground voltage to the scan line of each row. The control 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. The image update signal is related The image update in the display module; 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 and the image According to the image update signal, the driving module also 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 Following the change of the image update signal, the displayed image is updated. A scanning display, comprising: a light emitting diode direct display module, receiving a reference voltage and including a light emitting diode array of a common cathode structure, the light emitting diode array including a plurality of scanning lines arranged in a row direction with each other , A plurality of data lines are arranged perpendicularly to the scan lines along a row of each other, and a plurality of light-emitting diodes are respectively arranged correspondingly to the scan lines. Between the scan line and the matrix defined by the plurality of data lines, each light emitting diode has a cathode electrically connected to the scan line corresponding to the scan line, and an anode electrically connected to the data line corresponding to the data line; a driving device, It includes: a control module that generates an image stream and a synchronization control signal, and generates a plurality of switching signals corresponding to a plurality of scan lines to the light emitting diode according to the synchronization control signal and the image stream Body direct display module to control the light-emitting diode direct display module to transmit the reference voltage to the scan line of each row, scan the light-emitting diode direct display module, and the control module is also based on the synchronization The control signal and the switching signal corresponding to the scan line of the last row generate an image update signal; and 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 and the image update signal, the driving module further generates a plurality of driving signals to the light emitting diode direct display module according to the image update signal and the image stream. The multiple data lines. The scanning display according to claim 6, wherein the light-emitting diode direct display module includes: a scanning unit that receives a plurality of switching signals and the reference voltage and is electrically connected to each scan of the light-emitting diode array And is controlled by the plurality of switching signals to sequentially output the reference voltage to the scan line of each row of the light-emitting diode array. The scanning display according to claim 6, 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 electrically connected to the plurality of data lines of the backlight module, the control module and the storage unit, To receive the image update signal from the control module and the image stream from the storage unit, and generate a plurality of driving signals to the light-emitting diode array according to the image update signal and the image stream Of the multiple data lines. A driving device is suitable for electrically connecting a light emitting diode direct display module. The light emitting diode direct display module receives a ground voltage and includes a plurality of scan lines, a plurality of data lines, and a plurality of light emitting diodes, Each light emitting diode has a cathode that is electrically connected to the scan line and an anode that is electrically connected to the data line. The driving device includes: a control module that generates an image stream, and A synchronization control signal, and according to the synchronization control signal and the image stream, a plurality of switching signals corresponding to a plurality of scan lines are generated to the direct display module of the light emitting diode to control the direct display of the light emitting diode The module transmits the ground voltage to the scan line of each row, the control 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 a driving module, The LED direct display module is connected, and the control module is electrically connected to receive the synchronization control signal and the image stream and the image update signal. The driving module is also based on the image update signal and the image update signal. Image stream, respectively generate multiple drive signals to the multiple of the light-emitting diode direct display module Data lines. A driving method is executed by a scanning display. The scanning display includes a display module, a backlight module, and a driving device. The backlight module includes a plurality of scan lines, a plurality of data lines, and a plurality of light emitting diodes. Each light emitting diode has a cathode electrically connected to the scan line and an anode electrically connected to the data line. The driving method of the scanning display includes the following steps: (S) using The backlight module receives a ground voltage; (C) using the driving device to generate a plurality of switching signals corresponding to a plurality of scan lines to the backlight module according to a synchronous control signal and an image stream to control the backlight module The group transmits the ground voltage to the scan line of each row; (D) The driving device 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 Image update on the scanning display; and (E) using the driving device to generate 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 enable the display module to update the displayed image following the change of the image update signal.

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