TWI601109B - Timing controller circuit of electronic paper display apparatus - Google Patents

Description

Timing controller circuit of electronic paper display device

The present invention relates to a timing controller circuit, and more particularly to a timing controller circuit for an electronic paper display device.

In recent years, as display devices have gradually begun to develop in a lighter and thinner direction, electronic paper display devices have become a display device that meets the needs of the public. Electronic paper display devices have been widely used in electronic readers (for example, electronic books, electronic newspapers) or other electronic components (for example, electronic tags) because of their advantages of being thin, durable, and energy-saving and low-power consumption.

In the prior art, related applications of the electronic paper display device use an external microcontroller (MCU), a system on chip (SOC) or other embedded system as a system application master. The system application host controls the display function of the electronic paper display panel by controlling the timing controller circuit of the electronic paper display device. Therefore, in such related applications, all display control and display modes of the electronic paper display panel will be selected by the system application host. However, the display control and display mode will be extended by the system application master. The development time of the sub-paper display device, and its display quality will be difficult to adjust by the timing controller circuit.

The invention provides a timing controller circuit for an electronic paper display device for driving an electronic paper display panel to provide good display quality.

The timing controller circuit of the electronic paper display device of the present invention includes an image processing circuit and a timing controller. The image processing circuit is configured to receive the image signal, and analyze the image signal according to the signal component of the image signal to determine the display mode of the electronic paper display device. The image processing circuit is configured to select a driving signal waveform according to the determined display mode. The timing controller is electrically connected to the image processing circuit. The timing controller outputs the selected drive signal waveform to drive the electronic paper display panel of the electronic paper display device to display the image screen.

In an embodiment of the invention, the signal component is a gray-scale signal selected from the group consisting of image signals.

In an embodiment of the invention, the display modes described above include a static display mode and a dynamic display mode.

In an embodiment of the invention, the image signal includes a previous image frame and a current image frame. The image processing circuit determines whether the display mode is a static display mode or a dynamic display mode according to the difference between the previous image frame and the current image frame.

In an embodiment of the invention, if the difference between the previous image frame and the current image frame continues, the image processing circuit determines that the display mode is the dynamic display mode.

In an embodiment of the invention, if the difference between the previous image frame and the current image frame does not continue, the image processing circuit determines that the display mode is the static display mode.

In an embodiment of the invention, the image processing circuit analyzes the image signal according to the signal component of the image signal to determine the type of the image frame, and selects the driving signal waveform according to the determined type of the image image.

In an embodiment of the invention, the type of the image frame includes a black and white image frame and a grayscale image frame.

In an embodiment of the invention, the image processing circuit and the timing controller are disposed on the same wafer.

In an embodiment of the invention, the electronic paper display device includes a driving circuit for driving an electronic paper display panel to display an image of the image. The drive circuit is disposed on the electronic paper display panel. The timing controller outputs the selected drive signal waveform to the drive circuit. The driving circuit drives the electronic paper display panel to display an image screen according to the selected driving signal waveform.

Based on the above, in an exemplary embodiment of the present invention, the image processing circuit selects a driving signal waveform according to the determined display mode, and provides the timing controller to drive the electronic paper display panel, so that the electronic paper display panel can provide a good display. quality.

The above described features and advantages of the invention will be apparent from the following description.

100‧‧‧Electronic paper display device

110‧‧‧Sequence controller circuit

112‧‧‧Image Processing Circuit

114‧‧‧Timing controller

120‧‧‧electronic paper display panel

130‧‧‧Drive circuit

200‧‧‧Image signal source

310‧‧‧Decoder circuit

320‧‧‧ memory circuit

330‧‧‧First Circuit Block

332‧‧‧Gamma Correction Circuit

334‧‧‧Scale circuit

336‧‧‧Strengthened circuit

338‧‧‧jitter circuit

340‧‧‧Second circuit block

342‧‧‧Analytical circuit

344‧‧‧Judgement circuit

346‧‧‧Selection circuit

AA‧‧‧ display area

IN, DIN‧‧‧ video signals

DS, V1, V2, V3‧‧‧ drive signal waveforms

VDPS, VDNS‧‧‧ voltage

S100, S110, S120, S130, S140, S150, S160, S170‧‧ steps

1 is a schematic diagram showing a timing controller circuit of an electronic paper display device according to an embodiment of the present invention.

2 is a schematic diagram of an image processing circuit of the embodiment of FIG. 1.

3 is a schematic diagram showing one of the English letters of an image frame according to an embodiment of the present invention.

4 is a histogram of an image screen including the letter of FIG. 3, which shows the gray scale distribution of the entire image frame.

FIG. 5 is a schematic diagram showing an outline of one of the English words in the image frame according to another embodiment of the present invention.

6 is a histogram of an image screen including the word of FIG. 5, showing the gray scale distribution of the entire image frame.

FIG. 7 is a schematic diagram showing an outline of one of the English letters of the image frame according to another embodiment of the present invention.

FIG. 8 is a histogram of an image frame including the letter of FIG. 7 showing the gray scale distribution of the entire image frame.

FIG. 9 is a schematic diagram of an image screen according to another embodiment of the present invention.

10 is a histogram of the image frame of FIG. 9 showing the entirety of the image frame Gray scale distribution.

11, FIG. 12 and FIG. 13 illustrate driving signal waveforms of different embodiments of the present invention.

FIG. 14 is a schematic diagram showing a mode determining method according to an embodiment of the present invention.

The invention is illustrated by the following examples, but the invention is not limited to the illustrated embodiments. Further combinations are also allowed between the embodiments. The term "coupled" as used throughout the specification (including the scope of the claims) may be used in any direct or indirect connection. For example, the first device is coupled to the second device, and the first device is directly connected to the second device, or the first device is indirectly connected to the second device through other devices or some connection means. In addition, the term "signal" may refer to at least one current, voltage, charge, temperature, data, electromagnetic wave or any other one or more signals.

1 is a schematic diagram showing a timing controller circuit of an electronic paper display device according to an embodiment of the present invention. Referring to FIG. 1 , the electronic paper display device 100 of the present embodiment includes a timing controller circuit 110 , an electronic paper display panel 120 , and a driving circuit 130 . In the embodiment, the driving circuit 130 is disposed on the electronic paper display panel 120 for driving the electronic paper display panel 120 to display an image on the display area AA. In an embodiment, the driving circuit 130 can also be disposed independently of the electronic paper display panel 120.

In this embodiment, the image signal source 200 is used to output the image signal IN to the timing controller circuit 110. The image signal source 200 is, for example, a continuous video signal. Sources, including but not limited to High Definition Multimedia Interface (HDMI), Digital Visual Interface (DVI), Video Graphics Array (VGA) or other embedded systems The video interface of the liquid crystal display device.

In other words, in this embodiment, the timing controller circuit 110 of the electronic paper display panel 120 can use the video interface of the image signal source 200 to receive the image signal IN used in the prior art for output to the liquid crystal display device. That is, in the present embodiment, using the video interface of the video signal source 200 as an input interface, the timing controller circuit 110 of the electronic paper display device 100 can adaptively control and select the display mode to provide good display quality.

Specifically, the timing controller circuit 110 of the embodiment includes an image processing circuit 112 and a timing controller 114. The image processing circuit 112 and the timing controller 114 are disposed on the same wafer, for example, so that the timing controller circuit 110 can be adaptive. Control and select the display mode to provide good display quality. The display control and display mode of the electronic paper display device are all selected by the timing controller circuit 110, which is not the same as the prior art.

In this embodiment, the image processing circuit 112 is configured to receive the image signal IN and analyze the image signal IN according to the signal component of the image signal IN to determine whether the display mode of the electronic paper display device is a static display mode or a dynamic display mode. The image processing circuit 112 selects the driving signal waveform DS according to the determined display mode, such as shown in FIG. 11, FIG. 12 or FIG. In an embodiment, the signal component includes, for example, image resolution, image brightness, image spectral distribution, and image difference (image) Discrepancy), image relevancy, image color depth, image refresh rate, image grayscale distribution, or other similar image characteristics. In this embodiment, the signal component of the image signal IN is, for example, a gray-scale signal selected from the image signal IN.

In this embodiment, the timing controller 114 is electrically connected to the image processing circuit 112. The timing controller 114 outputs the driving signal waveform DS selected by the image processing circuit 112 to the driving circuit 130 to drive the electronic paper display panel 120 of the electronic paper display device 100 to display an image screen. Therefore, in the embodiment, the driving circuit 130 drives the electronic paper display panel 120 to display the image frame in the display area AA according to the driving signal waveform DS selected by the image processing circuit 112.

2 is a schematic diagram of an image processing circuit of the embodiment of FIG. 1. Referring to FIG. 2, the image processing circuit 112 of the present embodiment includes, for example, a decoder circuit 310, a memory circuit 320, a first circuit block 330, and a second circuit block 340. In the present embodiment, the first circuit block 330 includes a gamma correction circuit 332, a scaling circuit 334, an enhancement circuit 336, and a dither circuit 338. The second circuit block 340 includes an analysis circuit 342, a determination circuit 344, and a selection circuit 346.

In this embodiment, after the image signal IN is input to the image processing circuit 112, the image signal IN is decoded by the decoder circuit 310 to output the digital image signal DIN, and the digital image signal DIN is stored to the memory circuit 320. The digital video signal DIN output by the decoder circuit 310 includes, for example, a gray scale signal. For example, after decoding, the decoder circuit 310 outputs an image signal in the YCbCr format, and is used for consecutive images in the first circuit block 330 and the second circuit block 340. Reason. In the present embodiment, the Y value includes, for example, a gray scale signal as image data. The gray scale signal is processed in the first circuit block 330 using gamma correction. In the present embodiment, the image signal IN is, for example, a continuous input timing controller circuit 110. The timing controller 114 can set the sampling frequency of the image frame, for example, every 200 milliseconds, but the present invention does not limit the sampling frequency.

In this embodiment, the first circuit block 330 reads the gray-scale signal from the memory circuit 320, and sequentially performs the gamma on the gray-scale signal by using the gamma correction circuit 332, the scaling circuit 334, the enhancement circuit 336, and the jitter circuit 338. Image processing operations such as gamma correction operations, rescaling operations, CR/edge enhance operations, and Dithering processing. Then, the first circuit block 330 outputs the image data to the timing controller 114 to drive the electronic paper display panel 120 to display the image frame.

In the present embodiment, image processing operations such as gamma correction operation, rescaling operation, contrast/boundary enhancement operation, and dither processing may be performed by any one of gamma correction operations, rescaling operations, contrast/boundary enhancement operations, respectively, in the art. And the steps of the dither processing are implemented, and the invention is not limited.

In the present embodiment, the analysis circuit 342 of the second circuit block 340 analyzes the image signal IN according to, for example, a gray scale signal. The judging circuit 344 judges whether the display mode of the electronic paper display device 100 is the static display mode or the dynamic display mode based on the analysis result of the analysis circuit 342, and determines the type of the image screen. Next, the selection circuit 346 selects according to the display mode or the type of the image frame determined by the determination circuit 344. Select the appropriate drive signal waveform DS.

In the present embodiment, the analysis circuit 342 analyzes the gray scale distribution in the image frame, for example, using a histogram as shown in FIG. 4, FIG. 6, FIG. 8, or FIG. For example, FIG. 3 is a schematic diagram showing one of the English letters of an image frame according to an embodiment of the present invention. 4 is a histogram of an image screen including the letter of FIG. 3, which shows the gray scale distribution of the entire image frame. In the embodiment, the image displayed on the display area AA is, for example, an article or a paragraph of text, wherein the letters are, for example, the letters of FIG. 3, and the gray scale distribution is mainly black. Therefore, the histogram shown in FIG. 4 has a ratio of the black grayscale value G15 between 70% and 80%, the proportion of the white grayscale value G0 is close to 10%, and the proportion of the grayscale grayscale values G1 to G14. Less than 5% respectively. In this example, the image screen including the letter of FIG. 3 is determined by the analysis result of the analysis circuit 342, and the determination circuit 344 determines, for example, that the image screen is a black-and-white image.

FIG. 5 is a schematic diagram showing an outline of one of the English words in the image frame according to another embodiment of the present invention. 6 is a histogram of an image screen including the word of FIG. 5, showing the gray scale distribution of the entire image frame. In this embodiment, the image displayed on the display area AA is, for example, an article or a paragraph of text, wherein the word is, for example, the same as the word of FIG. 5, and the gray scale distribution is mainly black. Therefore, the histogram shown in FIG. 6 has a ratio of the black gray scale value G15 between 70% and 80%, and the ratio of the white gray scale value G0 to the gray gray scale value G1 to G14 is less than 5%. In this example, the image screen including the word of FIG. 5 is determined by the analysis result of the analysis circuit 342, and the determination circuit 344 determines, for example, that the image screen is a black-and-white image.

FIG. 7 is a schematic diagram showing an outline of one of the English letters of the image frame according to another embodiment of the present invention. FIG. 8 is a histogram of an image frame including the letter of FIG. 7 showing the gray scale distribution of the entire image frame. In this embodiment, the image displayed on the display area AA is, for example, an article or a paragraph of text, wherein the letters are, for example, the letters of FIG. 7, and the gray scale distribution is mainly black. Therefore, the histogram shown in FIG. 8 has a ratio of black gray scale value G15 between 80% and 90%, a white gray scale value G0 between 10% and 20%, and gray gray scale values G1 to G14. The share is almost 0%. In this example, the image screen including the letter of FIG. 7 is determined by the analysis result of the analysis circuit 342, and the determination circuit 344 determines, for example, that the image screen is a black-and-white image.

FIG. 9 is a schematic diagram of an image screen according to another embodiment of the present invention. FIG. 10 is a histogram of the image screen of FIG. 9 showing the gray scale distribution of the entire image frame. In this embodiment, the image displayed on the display area AA is, for example, an image, which may be a landscape image or a character image, and the gray scale distribution is substantially uniform. However, the present invention does not limit the content of the image. Therefore, the gray scale distribution of the histogram of the image picture displayed in the display area AA is as shown in FIG. In this example, the video screen of FIG. 9 is determined by the analysis result of the analysis circuit 342, and the determination circuit 344 determines, for example, that the video image is a grayscale video image.

Therefore, the determination circuit 344 determines the type of the image frame based on the analysis result of the analysis circuit 342. Next, the selection circuit 346 selects an appropriate driving signal waveform DS according to whether the type of the image screen determined by the determining circuit 344 is a black-and-white image screen or a gray-scale image screen.

11, FIG. 12 and FIG. 13 illustrate driving signal waveforms of different embodiments of the present invention. Referring to FIG. 11 to FIG. 13 , the driving signal waveform V1 illustrated in FIG. 11 is, for example, a display state in which the optical state of the particles in the electronic paper display panel 120 is driven from a white initial state to a black state. The driving signal waveform V2 shown in FIG. 12 is, for example, a display state in which the optical state of the particles in the electronic paper display panel 120 is driven from the initial state of black to white. The driving signal waveform V3 shown in FIG. 13 is, for example, a display state in which the optical state of the particles in the electronic paper display panel 120 is driven from a white initial state to a different gray. In FIGS. 11 to 13, the voltages VDPS and VDNS are the high level and the low level of the drive signal waveforms V1, V2, and V3, respectively. Moreover, the driving time of the driving signal waveforms V1 and V2 is 100 milliseconds to 300 milliseconds, which is shorter than the driving time of the driving signal waveform V3 by 500 milliseconds to 1500 milliseconds. In FIGS. 11 to 13, the lengths of the driving signal waveforms V1, V2, and V3 and their aspects are for illustrative purposes only, and the present invention is not limited thereto.

Therefore, in the example of the present invention, if the determination circuit 344 determines that the image frame is a black and white image frame, the selection circuit 346 selects, for example, the drive signal waveforms V1 and V2, and outputs the same to the timing controller 114. If the determination circuit 344 determines that the video image is a grayscale video image, the selection circuit 346 selects, for example, the drive signal waveforms V1, V2, and V3, and outputs the same to the timing controller 114.

In the present embodiment, the determination circuit 344 further determines whether the display mode of the electronic paper display device 100 is the static display mode or the dynamic display mode based on the analysis result of the analysis circuit 342. Next, the selection circuit 346 selects an appropriate drive signal waveform DS according to the display mode determined by the determination circuit 344.

For example, FIG. 14 is a schematic diagram of a mode determining method according to an embodiment of the present invention. Referring to FIG. 2 and FIG. 14, the mode determining method of this embodiment is applicable to at least the timing controller circuit 110 of FIG. Taking the timing controller circuit 110 of FIG. 2 as an example, in step S100, the analysis circuit 342 receives the image signal, and analyzes the image signal according to the signal component of the image signal. For example, the analysis circuit 342 analyzes the grayscale distribution in the image frame using a histogram as shown in FIG. 4, FIG. 6, FIG. 8, or FIG. In this embodiment, the image signal includes a previous image frame and a current image frame. Therefore, in step S100, the analysis result of the analysis circuit 342 includes the grayscale distribution of the previous image frame and the current image frame. In step S110, the determination circuit 344 determines whether there is a difference between the previous image frame and the current image frame, such as the difference in grayscale values, based on the analysis result of the analysis circuit 342. The present invention is not limited to the gray scale value difference described above, and the analysis circuit 342 can also analyze the resolution of the previous image frame and the current image frame, the image brightness or other similar image characteristics, and determine the difference by the determination circuit 344.

It is judged that if there is a difference, the mode determination method proceeds to step S120. In step S120, if there is a difference between the previous video screen and the current video screen, the determination circuit 344 increments the count value of the motion image by one. Next, in step S130, the determination circuit 344 determines whether the motion picture count value is greater than a preset value. If the dynamic image count value is greater than the preset value, it means that the difference between the previous image frame and the current image frame continues, that is, the continuous majority of the image images continue to have differences, and the number of image image differences is determined by the preset value. When the difference is continued, the mode determining method performs step S140, and the display mode of the electronic paper display device 100 of the determining circuit 344 is dynamic display. mode. If the dynamic image count value is not greater than the preset value, the mode determination method returns to step S100 to analyze the gray scale distribution in the image frame again.

It is judged that if there is no difference, the mode determination method proceeds to step S150. In step S150, if there is no difference between the previous image screen and the current image screen, the determination circuit 344 increments the count value of the still image by one. Next, in step S160, the determination circuit 344 determines whether the still image count value is greater than a preset value. If the static image count value is greater than the preset value, it means that the difference between the previous image frame and the current image frame is not continuous, that is, the continuous majority of the image images are the same, and the same number of image images is determined by the preset value. When the above difference does not continue, the mode determination method proceeds to step S170, and the determination circuit 344 displays the display mode of the electronic paper display device 100 as the static display mode. If the static image count value is not greater than the preset value, the mode determination method returns to step S100 to analyze the gray scale distribution in the image frame again.

In addition, the mode determining method of the embodiment of the present invention can obtain sufficient teachings, suggestions, and implementation descriptions from the description of the embodiment of FIG. 1 to FIG. 13 , and therefore will not be described again.

Therefore, with the mode determination method of FIG. 14, the determination circuit 344 determines whether the display mode of the electronic paper display device 100 is the static display mode or the dynamic display mode based on the analysis result of the analysis circuit 342. Next, the selection circuit 346 selects an appropriate drive signal waveform DS according to the display mode determined by the determination circuit 344. For example, in the dynamic display mode, the image frame continues to change for a period of time, and the selection circuit 346 drives the electronic paper display panel 120 to display dynamics, for example, by controlling the number of gray levels of the dithering process and selecting a driving signal waveform with a shorter driving time. Image screen. In silence In the state display mode, the image picture is maintained for a certain period of time, and the selection circuit 346 drives the electronic paper display panel 120 to display the still image picture, for example, by controlling the number of gray levels of the dithering process and selecting a driving signal waveform having a long driving time. Static mode can produce grayscale, but it will flash, while dynamic mode can only have black and white, but it will not flash. Therefore, select dynamic mode or static mode to display image screen according to the above method, which can display electronic paper. The panel provides good display quality.

In the embodiment of FIG. 1 and FIG. 2, each circuit block can be implemented by any suitable circuit architecture in the technical field, and the invention is not limited thereto. The detailed architecture and its implementation can be adequately taught, suggested, and implemented by the general knowledge in the art, and therefore will not be described again.

In summary, in an exemplary embodiment of the present invention, the image processing circuit selects a driving signal waveform according to the determined display mode or the type of the image screen, and provides the timing controller to drive the electronic paper display panel, thereby e-paper The display panel provides good display quality. In an exemplary embodiment of the present invention, the display control and display modes of the electronic paper display device are all selected by the timing controller circuit, which is not the same as the prior art.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧Electronic paper display device

110‧‧‧Sequence controller circuit

112‧‧‧Image Processing Circuit

114‧‧‧Timing controller

120‧‧‧electronic paper display panel

130‧‧‧Drive circuit

200‧‧‧Image signal source

AA‧‧‧ display area

IN‧‧‧ video signal

DS‧‧‧Drive Signal Waveform

Claims (10)

A timing controller circuit for an electronic paper display device, comprising: an image processing circuit for receiving an image signal, and analyzing the image signal according to a signal component of the image signal to determine a display mode of the electronic paper display device And selecting a driving signal waveform according to the determined display mode; and a timing controller electrically connected to the image processing circuit for outputting the selected driving signal waveform to drive an electron of the electronic paper display device The paper display panel displays an image screen. The timing controller circuit of claim 1, wherein the signal component is a gray-scale signal selected from the image signal. The timing controller circuit of claim 1, wherein the display mode comprises a static display mode and a dynamic display mode. The timing controller circuit of claim 3, wherein the image signal comprises a previous image frame and a current image frame, and the image processing circuit determines the difference according to the difference between the previous image frame and the current image frame. The display mode is the static display mode or the dynamic display mode. The timing controller circuit of claim 4, wherein if the difference between the previous image frame and the current image frame continues, the image processing circuit determines that the display mode is the dynamic display mode. The timing controller circuit of claim 4, wherein if the difference between the previous image frame and the current image frame does not continue, the image processing circuit determines that the display mode is the static display mode. The timing controller circuit of claim 1, wherein the image processing circuit analyzes the image signal according to the signal component of the image signal to determine the type of the image frame, and according to the determined image frame The type to select the drive signal waveform. The timing controller circuit of claim 7, wherein the type of the image frame comprises a black and white image frame and a grayscale image frame. The timing controller circuit of claim 1, wherein the image processing circuit and the timing controller are disposed on the same wafer. The timing controller circuit of claim 1, wherein the electronic paper display device comprises a driving circuit for driving the electronic paper display panel to display the image, the driving circuit is disposed on the electronic paper display panel And the timing controller outputs the selected driving signal waveform to the driving circuit, and the driving circuit drives the electronic paper display panel to display the image frame according to the selected driving signal waveform.