EP4207173A1

EP4207173A1 - E-paper display device

Info

Publication number: EP4207173A1
Application number: EP22170353.1A
Authority: EP
Inventors: Chao-Hsuan Huang; Yew-Chun Wang; Lung-Pin Chang
Original assignee: SES Imagotag SA
Current assignee: SES Imagotag SA
Priority date: 2021-12-30
Filing date: 2022-04-27
Publication date: 2023-07-05
Also published as: TW202326267A

Abstract

An e-paper display device (1) includes a driving substrate (11), an e-paper film (12), a driving chip (13), a system control board (14) and a voltage conversion circuit (15). The e-paper film is arranged on the driving substrate. The driving chip is arranged on the driving substrate and adjacent to the e-paper film. The driving chip is electrically connected with the driving substrate, and drives the e-paper film to display images through the driving substrate. The system control board includes a main control chip (141), and the main control chip is electrically connected with the driving substrate and the driving chip. The voltage conversion circuit outputs the DC voltage required for driving the e-paper film and transmits it to the driving substrate. The voltage conversion circuit is located in the driving chip or the main control chip.

Description

BACKGROUND

Technology Field

The present invention relates to a display device and, in particular, to an e-paper display device.

Description of Related Art

Regarding the existing display technologies, both the liquid crystal display device and the light-emitting diode display device still have the requirement of continuously supplying power. That is, the display device displays images while still needing the continuous power consumption. Therefore, a bi-stable electronic paper (e-paper) display device was developed accordingly. When the bi-stable e-paper display device displays an image or screen, it does not need to input additional power but the image or screen can be retained. In the e-paper display device, only when it changes to another state or displays another screen, the additional power is necessary. The features of low power consumption and memorability make the e-paper display device become one of the first choices for next-generation display devices.
In order to provide the DC voltage required for driving the display panel, the conventional electronic device usually needs a voltage converter (DC-to-DC converter) for converting the applied power into the DC voltage for the display panel. However, the circuit of the existing voltage converter is usually formed on the system control board, and the system control board is generally a printed circuit board. Since the circuit of the voltage converter usually includes ICs, transistors, resistors, capacitors, and other components, the printed circuit board (system control board) must have a large size for arranging these components thereon.

SUMMARY

One or more exemplary embodiment of this invention is to provide an e-paper display device which has a system control board with a relatively smaller dimension.
In an exemplary embodiment, an e-paper display device includes a driving substrate, an e-paper film, a driving chip, a system control board, and a voltage conversion circuit. The e-paper film is arranged on the driving substrate. The driving chip is arranged on the driving substrate and adjacent to the e-paper film. The driving chip is electrically connected with the driving substrate, and drives the e-paper film to display images through the driving substrate. The system control board includes a main control chip, and the main control chip is electrically connected with the driving substrate and the driving chip. The voltage conversion circuit outputs a DC voltage required for driving the e-paper film and transmitting the DC voltage to the driving substrate. The voltage conversion circuit is located in the driving chip or the main control chip.
In one embodiment, the driving substrate includes an e-paper arrangement area and a peripheral area adjacent to the e-paper arrangement area, the e-paper film is arranged on the e-paper arrangement area, and the driving chip is arranged on the peripheral area.
In one embodiment, the e-paper film is a microcapsule e-paper, a microcup e-paper, or a cholesteric liquid crystal e-paper.
In one embodiment, the driving substrate and the e-paper film form a display module, and the driving chip further includes a scan driver or/and a data driver for the display module.
In one embodiment, the main control chip includes a micro control unit.
In one embodiment, the voltage conversion circuit includes a boost circuit, a charge pump circuit, or a voltage stabilizer circuit.
In one embodiment, the main control chip provides a DC power to the voltage conversion circuit, and the voltage conversion circuit converts the DC power into the DC voltage required for driving the e-paper film.
In one embodiment, when the voltage conversion circuit is located in the driving chip, the voltage conversion circuit is formed in the driving chip by IC manufacturing processes.
In one embodiment, when the voltage conversion circuit is located in the main control chip, the voltage conversion circuit is formed in the main control chip by IC manufacturing processes.
In one embodiment, the e-paper display device further includes a connecting circuit board. The system control board and the driving substrate are connected to opposite sides of the connecting circuit board, respectively, and the system control board is electrically connected to the driving chip and the driving substrate via the connecting circuit board.
As mentioned above, in the e-paper display device of this invention, the driving chip is arranged on the driving substrate and adjacent to the e-paper film, the driving chip is electrically connected with the driving substrate and drives the e-paper film to display images through the driving substrate, the system control board includes a main control chip, the main control chip is electrically connected with the driving substrate and the driving chip, the voltage conversion circuit outputs a DC voltage required for driving the e-paper film and transmitting the DC voltage to the driving substrate, and the voltage conversion circuit is located in the driving chip or the main control chip. Based on the above-mentioned design, in the fabrication procedure of the driving chip or the main control chip, the voltage conversion circuit can be simultaneously formed by the same chip (semiconductor) manufacturing processes. Therefore, the manufactured voltage conversion circuit can have a smaller size, thereby making the entire dimension of the system control board of the e-paper display device smaller.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will become more fully understood from the detailed description and accompanying drawings, which are given for illustration only, and thus are not limitative of the present invention, and wherein:

FIG. 1 is a schematic diagram showing an e-paper display device according to an embodiment of this invention; and
FIG. 2 is a schematic diagram showing an e-paper display device according to another embodiment of this invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
FIG. 1 is a schematic diagram showing an e-paper display device 1 according to an embodiment of this invention. Referring to FIG. 1, the e-paper display device 1 includes a driving substrate 11, an e-paper film 12, a driving chip 13, a system control board 14, and a voltage conversion circuit 15. In addition, the e-paper display device 1 of this embodiment further includes a connecting circuit board 16.
The surface of the driving substrate 11 is configured with an e-paper arrangement area A1 and a peripheral area A2, which is located adjacent to the e-paper arrangement area A1. In this case, the e-paper arrangement area A1 is configured for the arrangement of the e-paper film 12, and the peripheral area A2 refers to the area of the driving substrate 11 other than the e-paper arrangement area A1. The e-paper arrangement area A1 and the peripheral area A2 are disposed adjacent to each other. In this embodiment, the peripheral area A2 is the area surrounding the e-paper arrangement area A1.
The e-paper film 12 is arranged on the e-paper arrangement area A1 of the driving substrate 11, and the driving substrate 11 can control the e-paper film 12 to display image(s). In some embodiments, the driving substrate 11 includes a plurality of pixels, and each pixel has at least one switch, such as a thin-film transistor (TFT), so that the driving substrate 11 is an AM (Active Matrix) TFT substrate for controlling the electric field of each individual pixel. In some embodiments, the driving substrate 11 can be a PM (Passive Matrix) driving substrate, and this invention is not limited thereto. The material of the driving substrate 11 can be changed based on the product requirement. In this embodiment, the driving substrate 11 can be a glass substrate, a plastic substrate, or a flexible substrate, and is configured with a pixel circuit. Herein, the material of the flexible substrate can be, for example but not limited to, polyimide (PI).
The e-paper film 12 is a bi-stable e-paper display device, which has the advantages of low power consumption and wide viewing angle. For example, the e-paper film 12 can be a microcapsule e-paper, a microcup e-paper, or a cholesteric liquid crystal e-paper, but this invention is not limited thereto. In some embodiments, when the e-paper film 12 is a microcapsule e-paper or a microcup e-paper, the display medium may include electrophoretic substances, and the electrophoretic substances include a plurality of charged light-colored pigment particles and a dark-colored medium solution. The pigment particles and the medium solution are respectively accommodated in a plurality of microcapsules, and an adhesive is used to bond the microcapsules. In another case, the electrophoretic substances may include dark-colored pigment particles and a light-colored medium solution. In another case, the electrophoretic substances may include pigment particles of multiple colors and a light-colored medium solution. This invention is not limited thereto.
The driving chip 13 is arranged on the driving substrate 11 and adjacent to the e-paper film 12. The driving chip 13 is arranged on the peripheral area A2 of the driving substrate 11 and electrically connected to the driving substrate 11. The driving chip 13 can drive the e-paper film 12 to display images through the driving substrate 11. Herein, the driving chip 13 is arranged on the peripheral area A2 by COG (Chip On Glass) technology. In some embodiments, the driving substrate 11 and the e-paper film 12 together form a display module, and the driving chip 13 further includes a scan driver or/and a data driver for the display module. In other words, the driving chip 13 has the scan driving function or the data driving function for driving the display module; or the driving chip 13 has the scan driving function and the data driving function (integrated function) for driving the display module. This invention is not limited thereto.
The system control board 14 includes a main control chip 141, and the main control chip 141 is electrically connected with the driving substrate 11 and the driving chip 13. In this case, the main control chip 141 includes a microcontroller unit (MCU). Two sides of the connecting circuit board 16 are connected to the system control board 14 and the driving substrate 11, respectively, and the system control board 14 is electrically connected to the driving substrate 11 and the driving chip 13 via the connecting circuit board 16. Specifically, the connecting circuit board 16 of this embodiment can be, for example but not limited to, a flexible circuit board, and the driving substrate 11 (the driving chip 13) and the system control board 14 are connected to the opposite sides of the connecting circuit board 16, respectively. The connecting circuit board 16 is electrically connected to the driving substrate 11 and the system control board 14, respectively. Accordingly, the main control chip 141 of the system control board 14 can electrically connect to the driving substrate 11 and the driving chip 13 via the connecting circuit board 16, thereby transmitting the driving signals for driving the e-paper film 12 to the driving substrate 11 so as to control the e-paper film 12 to display images. In some embodiments, the main control chip 141 can output digital driving signals to the driving substrate 11 via the Serial Peripheral Interface (SPI).
The voltage conversion circuit 15 is a reference circuit for outputting a DC voltage (reference voltage) required for driving the e-paper film 12 and transmitting the DC voltage to the driving substrate 11. In this case, the voltage conversion circuit 15 can be located in the driving chip 13 or the main control chip 141. Specifically, the voltage conversion circuit 15 can be a DC-to-DC convertor, and can be located in the driving chip 13 or the main control chip 141. In this embodiment, the voltage conversion circuit 15 is located, for example, in the main control chip 141. The used voltage conversion circuit 15 can be different based on various driving requirements of the e-paper film 12. For example, the voltage conversion circuit 15 can be a boost circuit, a charge pump circuit, a voltage stabilizer circuit, or any combination thereof, and this invention is not limited thereto.
In order to provide the reference voltage required for the e-paper film 12, the voltage conversion circuit 15 of this embodiment is located in the main control chip 141. In this embodiment, the main control chip 141 provides a DC power to the voltage conversion circuit 15, and the voltage conversion circuit 15 converts the DC power into the DC voltage required for driving the e-paper film 12 and transmits the DC voltage to the driving substrate 11 and the driving chip 13 through the connecting circuit board 16. Specifically, in the IC manufacturing processes for fabricating the main control chip 141, not only the circuit of the microcontroller unit is formed, but the voltage conversion circuit 15 is also formed in the main control chip 141 by the IC manufacturing processes. Accordingly, the voltage conversion circuit 15 located in the main control chip 141 can provide the DC voltage required for driving the e-paper film 12 via the connecting circuit board 16.
As mentioned above, in the conventional flat display device, the voltage conversion circuit for providing DC voltage to the display panel is formed on the system control board (generally a printed circuit board), and the voltage conversion circuit converts the power provided by the main control chip into the DC voltage required for driving the e-paper film and outputs the DC voltage to the driving substrate. Generally, the system control board is a printed circuit board, and the voltage conversion circuit generally includes ICs, TFTs, resistors, capacitors and other components, so that the dimension of the system control board must be large enough for installing these components. Different from the conventional design, in the e-paper display device 1 of this embodiment, the voltage conversion circuit 15, which provides the DC voltage required for the e-paper film 12, is arranged in the main control chip 141. Moreover, the voltage conversion circuit 15 can be simultaneously formed by the chip (semiconductor) manufacturing processes, which are used to manufacturing the main control chip 141, so that the voltage conversion circuit 15 can have a smaller size and the entire dimension of the system control board 14 can be smaller.
FIG. 2 is a schematic diagram showing an e-paper display device 1a according to another embodiment of this invention. The component arrangements and connections of the e-paper display device 1a of this embodiment as shown in FIG. 2 are mostly the same as those of the e-paper display device 1 of the previous embodiment. Unlike the previous embodiment, the voltage conversion circuit 15a of the e-paper display device 1a is located in the driving chip 13a. In this embodiment, the voltage conversion circuit 15a is also formed in the driving chip 13a by the IC manufacturing processes. Since the system control board 14a (and the main control chip 141) does not contain the voltage conversion circuit, the entire dimension of the system control board 14 (and the main control chip 141) can be smaller.
In summary, in the e-paper display device of this invention, the driving chip is arranged on the driving substrate and adjacent to the e-paper film, the driving chip is electrically connected with the driving substrate and drives the e-paper film to display images through the driving substrate, the system control board includes a main control chip, the main control chip is electrically connected with the driving substrate and the driving chip, the voltage conversion circuit outputs a DC voltage required for driving the e-paper film and transmitting the DC voltage to the driving substrate, and the voltage conversion circuit is located in the driving chip or the main control chip. Based on the above-mentioned design, in the fabrication procedure of the driving chip or the main control chip, the voltage conversion circuit can be simultaneously formed by the same chip (semiconductor) manufacturing processes. Therefore, the manufactured voltage conversion circuit can have a smaller size, thereby making the entire dimension of the system control board of the e-paper display device smaller.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.

Claims

An e-paper display device, comprising:
a driving substrate;

an e-paper film arranged on the driving substrate;

a driving chip arranged on the driving substrate and adjacent to the e-paper film, wherein the driving chip is electrically connected with the driving substrate, and the driving chip drives the e-paper film to display images through the driving substrate;

a system control board comprising a main control chip, wherein the main control chip is electrically connected with the driving substrate and the driving chip; and

a voltage conversion circuit outputting a DC voltage required for driving the e-paper film and transmitting the DC voltage to the driving substrate;

wherein, the voltage conversion circuit is located in the driving chip or the main control chip.
The e-paper display device of claim 1, wherein the driving substrate comprises an e-paper arrangement area and a peripheral area adjacent to the e-paper arrangement area, the e-paper film is arranged on the e-paper arrangement area, and the driving chip is arranged on the peripheral area.
The e-paper display device of claim 1, wherein the e-paper film is a microcapsule e-paper, a microcup e-paper, or a cholesteric liquid crystal e-paper.
The e-paper display device of claim 1, wherein the driving substrate and the e-paper film form a display module, and the driving chip further comprises a scan driver or/and a data driver for the display module.
The e-paper display device of claim 1, wherein the main control chip comprises a micro control unit.
The e-paper display device of claim 1, wherein the voltage conversion circuit comprises a boost circuit, a charge pump circuit, or a voltage stabilizer circuit.
The e-paper display device of claim 1, wherein the main control chip provides a DC power to the voltage conversion circuit, and the voltage conversion circuit converts the DC power into the DC voltage required for driving the e-paper film.
The e-paper display device of claim 1, wherein when the voltage conversion circuit is located in the driving chip, the voltage conversion circuit is formed in the driving chip by IC manufacturing processes.
The e-paper display device of claim 1, wherein when the voltage conversion circuit is located in the main control chip, the voltage conversion circuit is formed in the main control chip by IC manufacturing processes.
The e-paper display device of claim 1, further comprising:
a connecting circuit board, wherein the system control board and the driving substrate are connected to opposite sides of the connecting circuit board, respectively, and the system control board is electrically connected to the driving chip and the driving substrate via the connecting circuit board.