Electronic paper and control method

Abstract

We provide electronic paper and other technologies that reduce the burden on administrators while ensuring the quality of the display for those around them. [Solution] Electronic paper comprising: a display panel having pixels containing color particles that move in response to an applied voltage; a detection unit that detects at least one of the brightness around the display panel and the presence or absence of a person around the display panel; and a control unit that applies the voltage to the pixels and writes an image to the display panel, wherein the control unit performs a refresh process on the display panel based on the detection result of the detection unit.

Description

Technical Field

[0001] The present disclosure relates to electronic paper and a control method.

Background Art

[0002] Conventionally, electronic paper has been used as a display device that can be rewritten multiple times and has low power consumption.

[0003] An electrophoretic display device that enables a refresh operation of a display image while suppressing power consumption is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Updating the screen of the electronic paper takes about 20 to 30 seconds, and during the screen update, the screen flickers. Therefore, when there are people such as customers around the electronic paper, it is not operationally preferable to perform the screen update.

[0006] Also, when an administrator such as a store clerk executes the screen update of the electronic paper after the business hours end, there is a problem that the work burden of the administrator increases.

[0007] One aspect of the present disclosure aims to provide an electronic paper or the like that reduces the burden on the administrator and ensures the display quality for the surrounding people.

Means for Solving the Problems

[0008] An electronic paper according to one aspect of the present disclosure includes a display panel having pixels containing color particles that move in response to an applied voltage, a detection unit that detects at least one of the brightness around the display panel and the presence or absence of a person around the display panel, and a control unit that applies the voltage to the pixels to write an image to the display panel, wherein the control unit performs a refresh process on the display panel based on the detection result of the detection unit.

[0009] A control method for electronic paper according to one aspect of the present disclosure is a control method for electronic paper comprising a display panel having pixels that include color particles that move in response to an applied voltage, and includes a detection step of detecting at least one of the brightness around the display panel and the presence or absence of a person around the display panel; a writing step of applying the voltage to the pixels to write an image to the display panel; and a refresh step of performing a refresh process on the display panel based on the detection result of the detection step. [Effects of the Invention]

[0010] According to the electronic paper described in this disclosure, it is possible to reduce the burden on administrators and ensure the quality of the display to those around them. [Brief explanation of the drawing]

[0011] [Figure 1] This is a block diagram of an electronic paper according to an embodiment. [Figure 2] This is a schematic cross-sectional view showing the structure of an electronic paper according to an embodiment. [Figure 3] This is an enlarged diagram schematically showing the structure around the microcapsules of the electronic paper according to the embodiment. [Figure 4] This is a flowchart of the control method for electronic paper according to an embodiment. [Modes for carrying out the invention]

[0012] The embodiments will be described below with reference to the drawings. In the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant explanations are omitted.

[0013] Figure 1 is a block diagram of an electronic paper according to an embodiment.

[0014] The electronic paper 100 includes a display panel 10, a control unit 20, a detection unit 30, a communication unit 40, and a storage unit 50. The electronic paper 100 functions as a display device that displays images. The electronic paper 100 can be used, for example, as an electronic shelf label, electronic advertisement, e-book terminal, or electronic notebook. However, the electronic paper 100 may also be used as a device other than an electronic shelf label, electronic advertisement, e-book terminal, and electronic notebook.

[0015] The display panel 10 displays an image. The display panel 10 has pixels containing color particles that move in response to the applied voltage.

[0016] The control unit 20 controls the electronic paper 100. The control unit 20 applies voltage to the pixels of the display panel 10 to write an image to the display panel 10. The control unit 20 also performs a refresh process on the display panel 10, which involves writing again after the initial writing operation, based on the detection result of the detection unit 30. For example, the control unit 20 determines whether the detection result of the detection unit 30 satisfies the conditions for executing the refresh process, and if it determines that the detection result of the detection unit 30 satisfies the conditions for executing the refresh process, it performs the refresh process. In the refresh process, the same image that was displayed before the refresh process is rewritten. For example, a black or white image is written to the entire display panel 10, and then the image to be displayed is written. In detail, the refresh process is an operation in which a second voltage V2, which is different from the first voltage V1, which is the voltage corresponding to the display grayscale after the refresh process, is applied, and then the first voltage V1 is applied again. Therefore, before the application of the first voltage V1, which is the voltage corresponding to the original display grayscale, a second voltage V2, which is different from the first voltage V1, is applied, and then the first voltage V1 is applied again. As a result, the deterioration of display quality is effectively suppressed. The second voltage V2 may be, for example, a voltage corresponding to the maximum value of the display gradation, or a voltage corresponding to the minimum value of the display gradation, but is not limited to these.

[0017] The display gradation after the refresh process is identical to that before the refresh process. Therefore, the same display gradation as before the refresh process is reproduced after the refresh process. As a result, the display gradation is maintained while the deterioration of display quality is effectively suppressed.

[0018] The control unit 20 is implemented, for example, by a processor such as one or more CPUs (Central Processing Units), or by one or more logic circuits (hardware) formed on an integrated circuit chip (IC (Integrated Circuit)).

[0019] The detection unit 30 detects at least one of the brightness around the display panel 10 and the presence or absence of a person around the display panel 10. When the detection unit 30 detects the brightness around the display panel 10, the control unit 20 may perform a refresh process on the display panel 10 when the brightness detected by the detection unit 30 is below a threshold value. When the detection unit 30 detects the presence or absence of a person around the display panel 10, the control unit 20 may perform a refresh process on the display panel 10 when no person is detected by the detection unit 30.

[0020] Further, the detection unit 30 may photograph the periphery of the display panel 10, acquire the photographed image, and output the acquired image to the control unit 20. The control unit 20 acquires the image photographed by the detection unit 30. When a person around the display panel 10 is detected by the detection unit 30, the control unit 20 analyzes the acquired image, detects the direction in which the person shown in the image is looking, and may perform a refresh process on the display panel 10 when the person is not looking in the direction of the display panel 10. Incidentally, the detection unit 30 may analyze the photographed image, detect the direction in which the person shown in the image is looking, detect whether the person is looking in the direction of the display panel 10, and notify the control unit 20 of the presence or absence of a person looking in the direction of the display panel 10. The detection unit 30 is, for example, a brightness sensor, a human presence sensor, or a camera or the like. The detection unit 30 may include one or more sensors (brightness sensor, human presence sensor) and one or more cameras.

[0021] The communication unit 40 is, for example, an interface device for wireless communication. The communication unit 40 is, for example, a network interface controller. The communication unit 40 communicates with a personal computer or the like via a communication network such as the Internet and a public telephone network. The communication unit 40 can receive an instruction signal from an instruction terminal (not shown) such as a personal computer. Note that the communication unit 40 may be able to transmit and receive signals to and from an instruction terminal (not shown). Further, the communication unit 40 may be, for example, an interface device for wired communication.

[0022] The storage unit 50 stores data and computer programs necessary for the operation of the electronic paper 100. The data includes, for example, image data related to the display image to be displayed on the display panel 10. The storage unit 50 can be constituted by one or a plurality of storage devices such as a RAM (Random Access Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or ROM (Read Only Memory). The storage unit 50 may include a removable medium.

[0023] FIG. 2 is a cross-sectional view schematically showing the structure of the electronic paper according to the embodiment.

[0024] The electronic paper 100 further has a housing 1 that houses the display panel 10 and the control unit 20. The housing 1 has an opening 1a on the front surface. In addition, a detection unit 30 is provided on the front surface of the housing 1.

[0025] The display panel 10 displays an image. The display panel 10 is formed larger than the opening 1a of the housing 1 and is arranged to close the opening 1a. Among the display panel 10, the region corresponding to the opening 1a is a display region where the image is visually recognized by the user.

[0026] The display panel 10 further includes a first substrate 11, a second substrate 12 disposed opposite to the first substrate 11, a plurality of microcapsules 13, a first electrode 14, and a second electrode 15.

[0027] The first substrate 11 is formed of a transparent plate member or sheet member such as glass or resin. A antireflection film may be formed on the outer surface (opposite to the second substrate 12) of the first substrate 11, or a water repellent treatment may be applied. The second substrate 12 is formed of a plate member or sheet member such as glass or resin.

[0028] The microcapsules 13 are placed between the first substrate 11 and the second substrate 12. The microcapsules 13 are laid in a layer, for example, between the first substrate 11 and the second substrate 12. The microcapsules 13 are substantially spherical in shape. The microcapsules 13 have a diameter, for example, between several tens of micrometers and several hundred micrometers.

[0029] Figure 3 is a schematic enlarged view showing the structure around the microcapsules of the electronic paper according to the embodiment.

[0030] As shown in Figure 3, the microcapsule 13 comprises a membrane 131, a plurality of color particles 132, and a dispersion 133. The membrane 131 is, for example, transparent. The membrane 131 is, for example, a transparent resin membrane. The material of the membrane 131 is not particularly limited, but may be, for example, urethane resin, melamine resin, or rubber.

[0031] The color particles 132 are pigments. The color particles 132 constitute a part of the image displayed on the display panel 10. The color particles 132 move when a voltage is applied. In this embodiment, movement includes moving and rotating. In this embodiment, the color particles 132 are electrophoretic particles. Specifically, the color particles 132 move within the dispersion 133 in response to the voltage applied between the first electrode 14 and the second electrode 15. This causes a predetermined image to be displayed on the display panel 10.

[0032] The color particles 132 are, for example, organic or inorganic particles. In this embodiment, the color particles 132 include, for example, black particles 132a as a black pigment and white particles 132b as a white pigment. The black particles 132a as a black pigment are not particularly limited, but include, for example, carbon black or titanium black. The white particles 132b as a white pigment are not particularly limited, but include, for example, titanium dioxide or antimony trioxide. Note that the black particles 132a and the white particles 132b are examples of "color particles" as described herein.

[0033] The black particles 132a are, for example, negatively charged. On the other hand, the white particles 132b are, for example, positively charged. In other words, the black particles 132a and the white particles 132b are different in color and are charged with different polarities. It is also possible for the black particles 132a to be positively charged and the white particles 132b to be negatively charged.

[0034] In this embodiment, as described above, the color particles 132 include black pigment and white pigment. However, the color particles 132 may include pigments of other colors instead of black pigment and white pigment. In addition, the color particles 132 may include pigments of other colors in addition to black pigment and white pigment. For example, yellow pigment, red pigment, blue pigment, white pigment and / or green pigment may be used as other colored pigments.

[0035] The dispersion 133 is, for example, transparent. The dispersion 133 is an insulating liquid. The dispersion 133 is not particularly limited, but may contain, for example, water, alcoholic solvents, esters, ketones, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, or oils. In this embodiment, the dispersion 133 contains, for example, aliphatic hydrocarbons.

[0036] The first electrode 14 and the second electrode 15 are positioned opposite each other, with the microcapsule 13 in between.

[0037] The first electrode 14 is positioned, for example, on the outside (first substrate 11 side) relative to the microcapsule 13. The first electrode 14 may be formed, for example, on the first substrate 11. In this embodiment, the first electrode 14 is formed on the first substrate 11.

[0038] The first electrode 14 is formed of a light-transmitting conductive material. The first electrode 14 is not particularly limited, but for example, it is formed of ITO (Indium Tin Oxide). In this embodiment, the first electrode 14 is a common electrode. The first electrode 14 is provided, for example, one for multiple (in this case, all) pixels. The first electrode 14 is, for example, grounded and has a ground potential.

[0039] The second electrode 15 is positioned, for example, on the inside (second substrate 12 side) relative to the microcapsule 13. The second electrode 15 may be formed, for example, on the second substrate 12. In this embodiment, the second electrode 15 is formed on the second substrate 12.

[0040] The second electrode 15 is not particularly limited, but is formed of a metallic material such as copper. In this embodiment, the second electrode 15 is a pixel electrode. The second electrode 15 is formed in a substantially rectangular shape in plan view, and multiple electrodes are provided. The multiple second electrodes 15 are arranged adjacent to each other with a predetermined gap between them.

[0041] For example, when a positive potential is applied to the second electrode 15a, the black particles 132a between the second electrode 15a and the first electrode 14 are attracted to the second electrode 15a. Also, the white particles 132b between the second electrode 15a and the first electrode 14 are attracted to the first electrode 14.

[0042] On the other hand, for example, if a negative potential is applied to the second electrode 15b, the black particles 132a between the second electrode 15b and the first electrode 14 are attracted to the first electrode 14. Also, the white particles 132b between the second electrode 15b and the first electrode 14 are attracted to the second electrode 15b.

[0043] Figure 4 is a flowchart of the control method for electronic paper according to the embodiment.

[0044] In step S401, the control unit 20 writes an image to the display panel 10.

[0045] In step S402, the control unit 20 determines whether a predetermined time has elapsed since the previous image writing (the image writing in step S401 or the refresh process of rewriting the image in step S404). If it is determined that a predetermined time has elapsed since the previous image writing, the control proceeds to step S403. If it is determined that a predetermined time has not elapsed since the previous image writing, the process in step S402 is repeated until it is determined that a predetermined time has elapsed since the previous image writing. The predetermined time is set in advance. By determining whether a predetermined time has elapsed since the previous image writing, the refresh process can be prevented from being executed frequently, thereby reducing power consumption.

[0046] In step S403, the control unit 20 determines whether the detection result of the detection unit 30 satisfies the conditions for executing the refresh process. If it is determined that the detection result of the detection unit 30 satisfies the conditions for executing the refresh process, the control proceeds to step S404. If it is determined that the detection result of the detection unit 30 does not satisfy the conditions for executing the refresh process, the control returns to step S402. For example, the detection result of the detection unit 30 satisfies the conditions for executing the refresh process in the following cases.

[0047] For example, when the detection unit 30 detects the brightness around the display panel 10, the control unit 20 determines whether the detected brightness is below a threshold. If the detected brightness is below the threshold, it determines that the conditions for executing the refresh process are met, and the control proceeds to step S404.

[0048] Furthermore, for example, if the detection unit 30 detects the presence or absence of a person around the display panel 10 (for example, within a certain distance from the display panel 10), the control unit 20 determines that the conditions for executing the refresh process are met if no person is detected around the display panel 10, and the control proceeds to step S404. Note that the area around the display panel 10 where the detection unit 30 detects a person may be a specific direction, such as in front of the display panel 10, from which a person can see the display panel 10.

[0049] Furthermore, for example, if the detection unit 30 detects the presence or absence of a person around the display panel 10 (for example, within a certain distance from the display panel 10), and then takes a picture of the area around the display panel 10 and acquires the captured image, the control unit 20, if the detection unit 30 has detected a person, will, based on the image acquired by the detection unit 30, detect the direction in which the person in the acquired image (i.e., the person around the display panel 10) is looking. If the person is not looking in the direction of the display panel 10, the control unit 20 will determine that the conditions for executing the refresh process are met, and the control will proceed to step S404.

[0050] Furthermore, for example, if the detection unit 30 detects the brightness around the display panel 10 and the presence or absence of a person around the display panel 10, the control unit 20 determines that the conditions for executing the refresh process are met if the detected brightness is below a threshold or if no person is detected around the display panel 10, and the control proceeds to step S404.

[0051] In step S404, the control unit 20 performs a refresh process on the display panel 10, and control returns to step S402. In the refresh process, for example, the control unit 20 writes a second image (for example, a black image or a white image) that is different from the image (first image) written in step S401 to the display panel 10, and then writes the first image again.

[0052] For example, if the electronic paper 100 is installed in a store and the detection unit 30 detects the brightness around the display panel 10, during store operation, the store's lights are on, so the area around the display panel 10 is bright, and the brightness detected by the detection unit 30 is greater than the threshold. On the other hand, after the store closes, the store's lights are turned off, so the area around the display panel 10 becomes dark, and the brightness detected by the detection unit 30 falls below the threshold, and a refresh process is performed. Thus, with the electronic paper of this embodiment, a refresh process is not performed during store operation, and a refresh is automatically performed when there are no customers, such as after the store closes. This reduces the burden on the manager, ensures display quality for people in the surrounding area, and prevents afterimages.

[0053] For example, if the electronic paper 100 is installed in a store and the detection unit 30 detects the presence or absence of people around the display panel 10, the refresh process will not be performed if there are customers around the display panel 10, and the refresh will be performed automatically when there are no customers around the display panel 10. In addition, the electronic paper 10 detects the direction in which people around the display panel 10 are looking, and the refresh process will not be performed if the person is looking in the direction of the display panel 10, and the refresh process will be performed automatically if the person is not looking in the direction of the display panel 10. In this way, the electronic paper of this embodiment can reduce the burden on the manager, ensure the quality of the display for people in the surrounding area, and prevent afterimages.

[0054] Furthermore, this disclosure is not limited to the embodiments described above and is modifiable; the above configurations can be replaced with substantially identical configurations, configurations that produce the same effects, or configurations that can achieve the same purpose. [Explanation of Symbols]

[0055] 10 Display Panel 20 Control Unit 30 Detection unit 40 Communications Department 50 Storage section 100 e-paper

Claims

1. A display panel having pixels containing color particles that move in response to an applied voltage, A detection unit that detects at least one of the brightness around the display panel and the presence or absence of a person around the display panel, A control unit that applies the voltage to the pixels and writes an image to the display panel, Equipped with, The control unit performs a refresh process on the display panel of the electronic paper based on the detection result of the detection unit.

2. The detection unit detects the brightness around the display panel, The electronic paper according to claim 1, wherein if the brightness detected by the detection unit is below a threshold, the control unit performs the refresh process.

3. The detection unit detects the presence or absence of a person around the display panel, If the person is not detected by the detection unit, the control unit performs the refresh process, as described in claim 1.

4. The detection unit detects the brightness around the display panel and the presence or absence of a person around the display panel. The electronic paper according to claim 1, wherein the control unit performs the refresh process when the brightness detected by the detection unit is below a threshold or when the person is not detected by the detection unit.

5. The detection unit detects the presence or absence of a person around the display panel and acquires an image of the area around the display panel. The control unit, If the detection unit detects the person, the detection unit detects the direction the person is looking based on the image it has acquired. The electronic paper according to claim 1, wherein the refresh process is performed if the person is not looking in the direction of the display panel.

6. The refresh process described above is: After the refresh process, a second voltage different from the first voltage corresponding to the display grayscale of the image displayed on the display panel is applied to the pixels. The electronic paper according to any one of claims 1 to 5, wherein the first voltage is applied to the pixel after the second voltage is applied.

7. A method for controlling electronic paper, comprising a display panel having pixels containing color particles that move in response to an applied voltage, A detection step of detecting at least one of the brightness around the display panel and the presence or absence of a person around the display panel, A writing step of applying the voltage to the pixel and writing the image to the display panel, A refresh step which performs a refresh process on the display panel based on the detection result of the detection step, A method for controlling electronic paper, including...

Images