JP2016119065A - Display panel and display control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid superposition of a shadow of a grid structure on a received image of a position information pattern read by a reading device and decipher position coordinates with more accuracy.SOLUTION: A display panel forms a display control system with an optical pen. The display panel includes: a position information pattern layer that is formed according to a given law so as to cause the optical pen to specify position information designated by the optical pen on the display panel; a color filter layer in which a color filter sectioned by a grid structure is disposed; and an invisible light reflection layer that reflects at least a part of invisible light ejected from the optical pen to the optical pen through the position information pattern layer. The invisible light reflection layer is disposed between the position information pattern layer and the color filter layer.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a display panel and a display control system that can form a display control system together with a reader.

  For example, as in Patent Document 1, a technique of reading a position information pattern representing a coordinate position on a plane of a display device using a pen-type reading device is known. The reading device receives the invisible light reflected by the display device after emitting the invisible light, and specifies the coordinate position indicated on the display device based on the received invisible light.

International Publication No. 2013/161262

  Generally, a display device displays an image by transmitting light emitted from a backlight device through an RGB color filter. At this time, the R (Red) filter, the G (Green) filter, and the B (Blue) filter constituting the RGB color filter layer are partitioned by a lattice structure called a black matrix.

  When the position information pattern formed on the display device is read using the reading device, invisible light received by the reading device (invisible light reflected from the display device), a color filter layer partitioned by a black matrix is provided. It may contain transmitted light. At this time, the shadow of the lattice structure of the black matrix is superimposed on the received light image of the invisible light indicating the position information pattern, which causes a problem that the position coordinates cannot be accurately decoded.

  The present disclosure has been made in view of the above-described problems, and it is possible to avoid the shadow of the lattice structure being superimposed on the received light image of the position information pattern read by the reading device and to decode the position coordinates more accurately. Provided is a display panel and a display control system.

  A display panel according to the present disclosure is a display panel that can use an optical pen that emits invisible light and receives reflected invisible light, and includes position information for causing the optical pen to specify a position on the display panel. A pattern layer, a color filter layer including a color filter partitioned by a lattice structure, and a non-visible light reflecting layer having a shape that diffusely reflects a part of the non-visible light emitted from the optical pen. The visible light reflection layer is disposed between the position information pattern layer and the color filter layer, and the amount of light reflected by the non-visible light reflection layer and incident on the optical pen is reflected after being transmitted through the color filter layer and is not visible. The amount of light is greater than the amount of light incident on the optical pen through the light reflecting layer.

  A display control system according to the present disclosure is a system including an optical pen and a display panel, and the optical pen includes an emission unit that emits invisible light, a light receiving unit that receives invisible light, and a light receiving unit. A coordinate specifying unit that specifies position information that the optical pen points on the display panel based on the received invisible light, and the display panel is a pattern for causing the optical pen to specify the position on the display panel. A position information pattern layer having a color filter layer, a color filter layer including a color filter partitioned by a lattice structure, and a non-visible light reflecting layer having a shape that diffusely reflects at least part of the non-visible light emitted from the optical pen The invisible light reflection layer is disposed between the position information pattern layer and the color filter layer, and the amount of light reflected by the invisible light reflection layer and incident on the optical pen is the color filter layer. Compared to the amount of light entering the optical pen through a non-visible light reflective layer is reflected after being transmitted, a great amount of light.

  According to the present disclosure, it is possible to provide a display panel that can prevent the shadow of the lattice structure from being superimposed on the received light image of the position information pattern read by the reading device and can decode the position coordinates more accurately.

It is an image figure which shows the external appearance of a display control system. It is a block diagram which shows the structure of a display control system. 1 is a cross-sectional view of a display panel according to a first exemplary embodiment. It is the schematic for demonstrating the shape of a convex part. It is the schematic for demonstrating the shape of a convex part. It is an enlarged image figure for demonstrating a dot pattern. It is an enlarged image figure for demonstrating a dot pattern. It is the schematic for demonstrating that the information which digitized the position of a dot changes with the positions of a dot. It is the schematic for demonstrating that the information which digitized the position of a dot changes with the positions of a dot. It is the schematic for demonstrating that the information which digitized the position of a dot changes with the positions of a dot. It is the schematic for demonstrating that the information which digitized the position of a dot changes with the positions of a dot. It is a flowchart which shows operation | movement of a display control system. It is sectional drawing of the display panel concerning a comparative example. It is an image figure which shows the structure of the apparatus which measures the reflective characteristic of a display panel. It is a figure which shows the measurement result (standardized with a standard reflecting plate) of the reflection intensity ratio of the display panel concerning Embodiment 1, and the display panel concerning a comparative example. FIG. 4 is an explanatory diagram showing a dot pattern and a pixel structure taken with a digital pen for the display panel according to the first exemplary embodiment; It is explanatory drawing which shows the dot pattern and pixel structure which image | photographed with the digital pen about the display panel concerning a comparative example.

  Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

  The inventor provides the accompanying drawings and the following description in order for those skilled in the art to fully understand the present disclosure, and is not intended to limit the subject matter described in the claims. Absent.

(Embodiment 1)
FIG. 1 is an image diagram showing an appearance of the display control system according to the first embodiment. The display control system 100 includes a display device 200 and an optical digital pen (hereinafter simply referred to as “digital pen”) 300. The display device 200 includes a display panel 210. On the surface of the display panel 210, a display surface capable of displaying an image or the like is defined.

  On the display surface of the display panel 210, a dot pattern is provided according to a predetermined rule that represents information regarding a position on the display panel 210. A specific example of this dot pattern is described in, for example, US Pat. No. 8,534,566. The digital pen 300 optically reads the dot pattern at the pen tip position, thereby detecting information on the position on the display panel 210 where the tip of the digital pen 300 is located (hereinafter also referred to as “position information”). be able to. The display device 200 and the digital pen 300 are in wireless communication, and the digital pen 300 transmits the detected position information to the display device 200. Thereby, the display apparatus 200 can grasp position information indicating the pen tip position of the digital pen 300 and performs various display controls.

  For example, assume that the tip of the digital pen 300 is moved on the display panel 210. At this time, the digital pen 300 detects continuous position information as a locus of the tip of the digital pen 300 from the dot pattern continuously read. The digital pen 300 sequentially transmits the detected position information to the display device 200. Thereby, the display device 200 can continuously display dots on the display panel 210 according to the locus of the tip of the digital pen 300. Using this function, the user can input characters, figures, and the like by handwriting on the display panel 210 with the digital pen 300.

[1. Configuration of Display Control System 100]
Next, the configuration of the display control system 100 will be described. FIG. 2 is a block diagram showing the configuration of the display control system.

  The display device 200 includes a display panel 210, a receiving unit 230, a display side microcomputer 240, and a display device side memory 250. The display device 200 may have other electrical configurations, but the description is omitted.

  The receiving unit 230 receives a signal transmitted from the digital pen 300. The receiving unit 230 transmits the received signal to the display side microcomputer 240.

  The display-side microcomputer 240 includes a CPU and a memory. The display-side microcomputer 240 controls the content displayed on the display panel 210 based on the signal transmitted from the digital pen 300.

  The display device side memory 250 stores a program for operating the CPU of the display side microcomputer 240. The display-side microcomputer 240 can read and write information from the display device-side memory 250 as appropriate.

  Next, details of the configuration of the display panel 210 will be described. FIG. 3 is a cross-sectional view of the display panel 210 according to the first embodiment, and FIGS. 4A and 4B are schematic diagrams for explaining the shape of a convex portion 434 described later.

  As shown in FIG. 3, the display panel 210 includes an optical film 400a, a touch sensor glass 440, a liquid crystal panel 450, and a backlight device 460.

  The optical film 400 a is configured by laminating a dot pattern sheet 410 and an infrared reflection sheet 430. The dot pattern sheet 410 has a PET film 412 as a substrate, a dot pattern composed of a plurality of dots 411, and a dot flattening layer 413.

  The PET film 412 protects the surface of the display panel 210 and functions as a base material for laminating layers such as the dots 411.

  A plurality of dots 411 are laminated on the back surface of PET film 412 (the lower surface in FIG. 3). Each dot 411 protrudes from the back surface of the PET film 412 by the thickness of the dot 411. One dot pattern is formed by a set of a plurality of dots 411 in the unit area 213, which will be described in detail later. The dots 411 are formed of a material that transmits visible light but absorbs infrared light (a material having low transmittance with respect to infrared light).

  The dot flattening layer 413 is laminated on the back surface of the PET film 412 so as to fill a space between the plurality of dots 411. That is, the dot flattening layer 413 is formed so as to cover the back surface of the PET film 412 and the surfaces of the plurality of dots 411. The dot flattening layer 413 is formed over the entire back surface of the PET film 412. The back surface of the dot flattening layer 413 is a flat surface. The dot flattening layer 413 is formed of a material that transmits both visible light and infrared light. The dot flattening layer 413 is formed of, for example, an acrylic resin. The dot flattening layer 413 has the same refractive index as that of the dots 411.

  As shown in FIG. 3, the infrared reflection sheet 430 includes an uneven base material 433 in which unevenness is formed by a plurality of convex portions 434, and an infrared reflective layer formed along the convex portions 434 of the uneven base material 433. 432. The convex portion 434 has a defined fine uneven shape in order to improve infrared reflection performance.

  Specifically, as shown in FIG. 4A, the convex portion 434 has an absolute inclination angle θ defined by an angle (<90 °) formed by the tangent line of the convex portion 434 and the reference plane with respect to the reference plane (x-axis in FIG. 4A). When the absolute inclination angle θ of the convex portion 434 is 25 °, the distribution rate f (θ = 25 °) is 0.5 (% / °) or more and the effective total of the infrared reflecting sheet 430 is In the area, the ratio of the projected area occupied by the region where the absolute inclination angle θ of the convex portion 434 is 40 ° or more is 20% or less. Here, the distribution rate f (θ) is expressed by the following formula (1).

Distribution ratio f (θ) = (ds / S) / dθ Equation (1)
S represents the effective total area of each convex portion 434. The effective total area is an area per one convex portion 434 in the entire area of the infrared reflection sheet 430. That is, S shown in FIG. 4B.

  Dθ represents a minute angle near the absolute inclination angle θ.

  Ds represents a projected area occupied by a region where the absolute inclination angle of the convex portion 434 is in the range of θ to θ + dθ within the effective plane. Specifically, in FIG. 4A, the contact point between the tangent line of the absolute inclination angle θ and the convex part 434 is A, the contact point of the tangent line of the absolute inclination angle θ + dθ and the convex part 434 is B, and the contact points A and B are the reference planes. Let C be the projected area. At this time, a set of regions C that can be performed in the same manner on the entire circumference of the convex portion 434 is a hatched region shown in FIG.

  By satisfying the above conditions, infrared diffuse reflection characteristics can be imparted to the infrared reflective sheet 430. The infrared light emitted from the illumination unit 380 built in the digital pen 300 is diffusely reflected by the infrared reflection sheet 430, and the infrared reflected light is incident on the image sensor 350 built in the digital pen 300. it can.

  The infrared reflection layer 432 is a layer that reflects infrared light (for example, 50% reflection) while transmitting visible light (for example, 90% transmission). When viewed microscopically, the infrared reflection layer 432 specularly reflects infrared rays. On the other hand, when viewed macroscopically, the infrared reflection sheet 430 functions as an infrared diffuse reflection member that diffuses and reflects infrared rays because the infrared reflection layer 432 is formed along the convex portions 434.

  The transparent adhesive layer 431 is a layer for adhering the dot pattern sheet 410 and the infrared reflective sheet 430. The transparent adhesive layer 431 has a refractive index substantially equal to the refractive index of the materials of the PET film 412, the dot flattening layer 413, and the uneven substrate 433. The surface of the infrared reflective sheet 430 on the dot pattern sheet 410 side has a concavo-convex shape due to the convex portion 434. Therefore, when the dot pattern sheet 410 and the infrared reflection sheet 430 are bonded, the transparent adhesive layer 431 functions to optically couple the gaps by flattening the uneven shape. In the above description, the dot planarization layer 413 and the transparent adhesive layer 431 are described as separate layers, but the present disclosure is not limited to this. That is, the dot flattening layer 413 may also serve as the transparent adhesive layer 431.

  The touch sensor glass 440 is a glass provided with a sensor that detects a user's touch operation on the display panel 210 by a known technique. The touch sensor glass 440 is disposed on the back surface (the bottom surface in FIG. 3) of the infrared reflective sheet 430.

  The liquid crystal panel 450 is a device that displays an image based on visible light irradiation using the backlight device 460 as a light source by controlling the orientation of liquid crystal molecules. The liquid crystal panel 450 includes a color filter layer 451 including a black matrix 453, a liquid crystal layer, and the like. The black matrix 453 forms, for example, a lattice structure (pixel structure) that partitions the RGB color filters 452. On the back surface of the liquid crystal panel 450, a backlight device 460 for irradiating the liquid crystal panel 450 with light is disposed. A voltage for changing the liquid crystal alignment of the liquid crystal layer is applied to the liquid crystal panel 450 based on display control by the display-side microcomputer 240. Accordingly, the liquid crystal panel 450 controls the amount of light transmitted from the backlight device 460 and executes various display operations. The liquid crystal panel 450 is disposed on the back surface of the touch sensor glass 440 (the lower surface in FIG. 3).

  By arranging as described above, a part of infrared light emitted from the illumination unit 380 built in the digital pen 300 is diffusely reflected by the infrared reflection sheet 430, and the image sensor built in the digital pen 300 is used. Infrared reflected light can be incident on 350, and the dot pattern sheet 410 can be read regardless of the angle of the digital pen 300.

  Further, a part of the reflected light that passes through the infrared reflecting sheet 430 and the color filter layer 451 and returns to the digital pen 300, that is, a part of the reflected light that is reflected by the backlight device 460 and the like and returns to the infrared reflecting sheet 430 is transmitted. The remaining part is diffusely reflected, so that the amount of reflected light reflected from the color filter layer 451 and returning to the digital pen 300 is reduced.

  That is, the amount of light that is reflected by the infrared reflecting sheet 430 and incident on the digital pen 300 is compared with the amount of light that is reflected after passing through the color filter layer 451 and incident on the digital pen 300 via the infrared reflecting sheet 430. , It becomes a big light quantity.

  Next, a detailed configuration of the digital pen 300 will be described with reference to FIG.

  The digital pen 300 includes a cylindrical main body case 310 and a pen tip portion 320 attached to the tip of the main body case 310. The digital pen 300 includes a pressure sensor 330, an objective lens 340, an image sensor 350, a pen side microcomputer 360, a pen side memory 390, a transmission unit 370, and an illumination unit 380 inside the main body case 310.

  The main body case 310 has the same outer shape as a general pen and is formed in a cylindrical shape. The pen tip portion 320 is formed in a tapered shape. The tip of the pen tip 320 is rounded to the extent that the surface of the display panel 210 is not damaged. Note that the shape of the pen tip portion 320 is preferably a shape that allows the user to easily recognize an image displayed on the display panel 210.

  The pressure sensor 330 is built in the main body case 310 and connected to the proximal end portion of the pen tip portion 320. The pressure sensor 330 detects the pressure applied to the pen tip portion 320 and transmits the detection result to the pen-side microcomputer 360. Specifically, the pressure sensor 330 detects the pressure applied from the display panel 210 to the pen tip portion 320 when the user enters characters or the like on the display panel 210 using the digital pen 300. The pressure sensor 330 is used, for example, when determining whether or not the user intends to input using the digital pen 300.

  The illumination unit 380 is provided at the tip of the main body case 310 and in the vicinity of the pen tip unit 320. The illumination part 380 irradiates invisible light, for example, is comprised by infrared LED. The illumination unit 380 is provided to irradiate infrared light from the tip of the main body case 310 when the user's input intention is determined based on the detection result of the pressure sensor 330.

  The objective lens 340 causes the image sensor 350 to form an image of light incident from the pen tip side. The objective lens 340 is provided at the distal end portion of the main body case 310 and in the vicinity of the pen tip portion 320. When infrared light is irradiated from the illumination unit 380 with the tip of the digital pen 300 facing the display surface of the display device 200, the infrared light is transmitted through the display panel 210, and the infrared reflection sheet 430 or the display panel 210 is transmitted. Is diffusely reflected by the liquid crystal panel 450 or the like located on the back side of the screen. As a result, part of the infrared light transmitted through the display panel 210 returns to the digital pen 300 side. Infrared light emitted from the illumination unit 380 and diffusely reflected by the display device 200 is incident on the objective lens 340. The image sensor 350 is provided on the optical axis of the objective lens 340. Therefore, the infrared light that has passed through the objective lens 340 is imaged on the imaging surface of the image sensor 350.

  The image sensor 350 outputs an image signal obtained by converting an optical image formed on the imaging surface into an electrical signal to the pen-side microcomputer 360. The image sensor 350 is configured by, for example, a CCD image sensor or a CMOS image sensor. As will be described in detail later, the dots 411 constituting the dot pattern are formed of a material that absorbs infrared light (a material with low transmittance for infrared light). Therefore, the infrared light hardly returns to the digital pen 300 from the dots 411 constituting the dot pattern. On the other hand, more infrared light returns from the area between the dots 411 than from the area of the dots 411. As a result, an optical image in which the dot pattern is expressed in black is captured by the image sensor 350.

  The pen-side microcomputer 360 specifies position information on the display panel 210 of the digital pen 300 based on an image signal generated by imaging by the image sensor 350. Specifically, the pen-side microcomputer 360 acquires the pattern shape of the dot pattern from the image signal generated by imaging by the image sensor 350, and specifies the position of the pen tip 320 on the display panel 210 based on the pattern shape. .

  The pen side memory 390 stores a program for operating the CPU of the pen side microcomputer 360. The pen side microcomputer 360 can read and write information from the pen side memory 390 as appropriate.

  Transmitter 370 transmits the signal to the outside. Specifically, the transmission unit 370 transmits the position information specified by the pen-side microcomputer 360 to the reception unit 230 of the display device 200 that is a wireless communication partner.

[2. Details of dot pattern]
Details of the dot pattern will be described below. 5A and 5B are enlarged image diagrams for explaining a dot pattern. In FIG. 5A, in order to explain the position of the dot 411 of the dot pattern, the first reference line 414 and the second reference line imaginary lines (lines that do not actually exist on the optical film 400a) are shown on the optical film 400a. Reference line 415 is described. The first reference line 414 and the second reference line 415 are orthogonal to each other. In FIG. 5A, a plurality of first reference lines 414 and a plurality of second reference lines 415 form a lattice.

  Each dot 411 is arranged around the intersection of the first reference line 414 and the second reference line 415. That is, each dot 411 is arranged in the vicinity of each lattice point. 6A, 6B, 6C, and 6D are diagrams showing the arrangement pattern of the dots 411. FIG. Each dot 411 has an X direction from the intersection of the first reference line 414 and the second reference line 415 when the extending direction of the first reference line 414 is the X direction and the extending direction of the second reference line 415 is the Y direction. It is disposed at a position offset (shifted) to the plus side or the minus side along the direction or the Y direction. Specifically, in the optical film 400a, the dots 411 are arranged in any one of FIGS. 6A to 6D. In the arrangement of FIG. 6A, the dot 411 is arranged at a position above the intersection of the first reference line 414 and the second reference line 415. When this arrangement is digitized, it is represented by “1”. In the arrangement of FIG. 6B, the dot 411 is arranged at a position on the right side of the intersection of the first reference line 414 and the second reference line 415. When this arrangement is digitized, it is represented by “2”. In the arrangement of FIG. 6C, the dot 411 is arranged at a position below the intersection of the first reference line 414 and the second reference line 415. When this arrangement is digitized, it is represented by “3”. In the arrangement of FIG. 6D, the dot 411 is arranged at a position on the left side of the intersection of the first reference line 414 and the second reference line 415. When this arrangement is digitized, it is represented by “4”. As described above, each dot 411 is represented by a numerical value from “1” to “4” in the digital pen 300 according to the arrangement pattern.

Then, as shown in FIG. 5B, one dot pattern is formed by 36 dots 411 included in the unit area 213 with 6 dots × 6 dots as one unit area 213. By arranging each of the 36 dots 411 included in the unit area 213 in any one of the arrangements shown in FIGS. 6A to 6D, a huge number (6 dots × 6 dots having one unit area having different information) can be obtained. In this case, 4 dot patterns can be formed. Depending on the dot interval, for example, coordinates of a vast plane of 60 million km ² can be defined by a dot pattern. In this vast, each dot pattern in which coordinates are defined on a plane is a different dot pattern. In the optical film 400a, a very small part of the plane is cut out and used in the vast plane defined by the dot pattern.

  Information on position coordinates for each unit area is added to each dot pattern of the optical film 400a. That is, when the optical film 400 a is divided into unit areas 213 of 6 dots × 6 dots, each dot pattern represents the position coordinates of the unit area 213. The order of arrangement in which the dots 411 are offset (shifted) along the X direction or the Y direction is designed on the basis of a number sequence designed in advance, such as an M series, and has a constant law continuously in the X and Y directions. They are lined up. If there is a dot 411 that cannot be read in the unit area, a dot around the unit area is referred to and a Hamming distance or the like is calculated. By determining the similarity between this calculation result and the numerical sequence that is the design value, even if there are several dots 411 that could not be read, the offset (shift) direction of the dots 411 that could not be read can be estimated. However, since there is a limit to the estimation, it is desirable that the dot 411 can read all the numbers in the unit area as much as possible. In addition, a well-known method can be used for the patterning (coding) and coordinate transformation (decoding) of the dot pattern as described above.

  Subsequently, a display operation of the display control system 100 configured as described above will be described. FIG. 7 is a flowchart showing the flow of the display operation. In the following, a case where the user performs a pen input (entry) on the display device 200 using the digital pen 300 will be described.

  First, the display device 200 and the digital pen 300 constituting the display control system 100 are turned on. As a result, the display-side microcomputer 240 is supplied with power from a power source (not shown) and completes initial operations for executing various operations. Similarly, the pen-side microcomputer 360 is supplied with power from a power supply (not shown), and completes initial operations for executing various operations. The display device 200 and the digital pen 300 establish wireless communication with each other. As a result, communication from the transmission unit 370 of the digital pen 300 to the reception unit 230 of the display device 200 is enabled.

  Subsequently, the pen-side microcomputer 360 of the digital pen 300 starts monitoring the pressure acting on the pen tip portion 320 (S500). This pressure is detected by the pressure sensor 330. While the pressure is not detected by the pressure sensor 330 (while No in S500 continues), the pen-side microcomputer 360 repeats step S500. When the pressure is detected by the pressure sensor 330 (Yes in S500), the pen-side microcomputer 360 determines that the user is pen-inputting characters or the like to the display panel 210 of the display device 200, and the illumination unit 380 Infrared light irradiation is started.

  Next, the dot pattern formed on the display panel 210 at the pen tip position is detected by the objective lens 340 and the image sensor 350 (S510). Here, the infrared light irradiated from the illumination unit 380 is diffusely reflected by the infrared reflection sheet 430 or the liquid crystal panel 450, and a part of the infrared light returns to the digital pen 300 side.

  Infrared light returning to the digital pen 300 side hardly transmits the dots 411 of the dot pattern. Infrared light that has mainly passed through the region between the dots 411 reaches the objective lens 340. The infrared light is received by the image sensor 350 through the objective lens 340. The objective lens 340 is disposed on the display panel 210 so as to receive reflected light from the position indicated by the pen tip portion 320. As a result, the dot pattern at the indicated position of the pen tip 320 on the display surface of the display panel 210 is imaged by the image sensor 350. In this way, the dot pattern is optically read by the objective lens 340 and the image sensor 350. An image signal generated by the imaging of the image sensor 350 is transmitted to the pen side microcomputer 360.

  Next, the pen side microcomputer 360 acquires the pattern shape of the dot pattern from the received image signal, and specifies the position of the pen tip on the display panel 210 based on the pattern shape (S520). Specifically, the pen side microcomputer 360 acquires the pattern shape of the dot pattern by performing predetermined image processing on the obtained image signal. Subsequently, the pen-side microcomputer 360 determines which unit area (6 dot × 6 dot unit area) from the arrangement of the dots 411 in the acquired pattern shape, and the position of the unit area from the dot pattern of the unit area. Specify coordinates (position information). The pen-side microcomputer 360 converts the dot pattern into position coordinates by a predetermined calculation corresponding to the dot pattern coding method.

  Then, the pen-side microcomputer 360 transmits the specified position information to the display device 200 via the transmission unit 370 (S530). Thereby, the display apparatus 200 can grasp the pen tip position of the digital pen 300.

  The position information transmitted from the digital pen 300 is received by the receiving unit 230 of the display device 200. The received position information is transmitted from the receiving unit 230 to the display-side microcomputer 240.

  When the display-side microcomputer 240 receives the position information, the display-side microcomputer 240 performs a display operation corresponding to the display surface on the display panel 210. Specifically, the display-side microcomputer 240 controls the display panel 210 so as to change the display content of the position corresponding to the position information in the display area of the display panel 210. In this example, since the character is input, the display-side microcomputer 240 displays a point at a position corresponding to the position information in the display area of the display panel 210. When the pen input with the digital pen 300 is continued, the display-side microcomputer 240 continuously acquires the position information. Accordingly, the display-side microcomputer 240 can continuously display dots at the position of the pen tip portion 320 on the display area of the display panel 210 following the movement of the pen tip portion 320 of the digital pen 300. . That is, the display-side microcomputer 240 can display characters on the display panel 210 according to the locus of the pen tip portion 320 of the digital pen 300.

  In addition, although the above description demonstrated the case where a character was entered on a display surface, the usage of the display control system 100 is not restricted to this. Of course, not only characters (numbers etc.) but also symbols and figures can be entered, but the digital pen 300 can be used like an eraser to erase characters and figures displayed on the display panel 210. You can also. Furthermore, using the digital pen 300 like a mouse, the cursor displayed on the display panel 210 can be moved, or the icon displayed on the display panel 210 can be selected. In other words, a graphical user interface (GUI) can be operated using the digital pen 300.

[3. Experimental result]
The measurement result of the reflection intensity of infrared light will be described for the display panel 210 according to the first embodiment formed with the above configuration.

  Here, for comparison with the display panel 210 according to the first embodiment, a display panel 700 as shown in FIG. 8 is created. FIG. 8 is a cross-sectional view of a display panel 700 according to a comparative example. As shown in FIG. 8, the display panel 700 according to the comparative example is a panel obtained by removing the infrared reflective sheet 430 from the display panel 210 according to the first embodiment.

  The digital pen 300 is configured using an infrared light emitting LED having a peak wavelength of 950 nm as the LED 150.

  Next, measurement of diffuse reflection characteristics of the display panel 210 according to the first embodiment and the display panel 700 according to the comparative example created as described above will be described. The diffuse reflection characteristic was measured by using a diffuse reflection measurement apparatus 500 as shown in FIG. 9 and capturing only the component that was irradiated with light from a specific angle and returned in the incident direction.

  FIG. 9 is an image diagram showing a configuration of an apparatus for measuring the reflection characteristic of the display panel 210. As shown in FIG. 9, the diffuse reflection measurement apparatus 500 includes a light source and a spectroscope (not shown) and a probe 530. The light source emits light including light from the visible region to the infrared region. The light emitted from the light source enters the sample (display panels 210 and 700) via the probe 530. The probe 530 includes seven optical fibers, one at the center is connected to the spectroscope, and six at the periphery are connected to the light source. The probe 530 is tilted by a measurement angle φ (an angle corresponding to the tilt angle φ of the digital pen 300) from the normal direction of the surface of the sample (display panels 210 and 700) to the sample (display panels 210 and 700). Irradiate light. The sample (display panels 210 and 700) reflects part of the light emitted from the probe 530 toward the probe 530. This reflected light is guided to the spectroscope via the probe 530. Thus, the spectroscope performs spectroscopic measurement. As a reference for spectroscopic measurement, a standard reflector 600 having a complete diffusion surface 610 laminated on the surface as shown in FIG. 9 is used. Then, by taking a ratio between the light intensity obtained by the diffuse reflection measurement device 500 and the measurement result of the light intensity by the standard reflection plate 600, the reflection intensity ratio normalized by the standard reflection plate of the display device 200 is obtained. calculate.

  FIG. 10 is a diagram illustrating a measurement result of the reflection intensity ratio between the display panel 210 according to the first embodiment and the display panel 700 according to the comparative example (standardized by the standard reflector 600). More specifically, the reflection intensity ratio for each measurement angle (0 ° to 40 °) at a wavelength of 950 nm is indicated by a solid line and a broken line. Here, a solid line A in FIG. 10 indicates the reflection intensity ratio of the display panel 210 according to the first embodiment. On the other hand, a broken line B in FIG. 10 indicates the reflection intensity ratio of the display panel 700 according to the comparative example. As shown in FIG. 10, the display panel 210 according to the first embodiment has a higher reflectance than the display panel 700 according to the comparative example in the entire measurement angle (0 ° to 40 °) range. Yes. This is because in the display panel 210 according to the first embodiment, the influence of reflected light from the infrared reflection sheet 430 disposed between the dot pattern sheet 410 and the color filter layer 451 is large.

  Subsequently, for these samples (display panels 210 and 700), a position information pattern reading test was performed using the digital pen 300. Specifically, a position information pattern was photographed for these samples (display panels 210 and 700) by an image sensor 350 for infrared detection built in the digital pen 300. At this time, the measurement angle of the digital pen 300 is 40 degrees. FIG. 11A and FIG. 11B show the imaging results.

  FIG. 11A and FIG. 11B are explanatory diagrams illustrating a dot pattern and a pixel structure captured by the digital pen 300 for the display panel 210 according to the first embodiment and the display panel 700 according to the comparative example.

  FIG. 11A is an image obtained by photographing the display panel 210 according to the first embodiment with the digital pen 300. On the other hand, FIG. 11B is an image obtained by photographing the display panel 700 according to the comparative example with the digital pen 300. In FIG. 11A and FIG. 11B, a plurality of point groups reflected in black are dot patterns formed by dots 411.

  As shown in FIG. 11B, in the image obtained by photographing the display panel 700 according to the comparative example, in addition to the dot pattern, the shadow of the lattice structure (pixel structure) by the black matrix 453 arranged in the color filter layer 451 is superimposed. Yes. And the contrast of a dot pattern is bad. This is because the digital pen 300 receives light including a dot pattern image by reflected light that has passed through the black matrix 453 disposed in the color filter layer 451. As described above, even if the dot pattern has a low contrast, even if there are several dots 411 that could not be read, the offset (shift) direction of the dots 411 that could not be read can be estimated. Still, when the contrast is low, the offset of the dot 411 cannot be sufficiently estimated, and the detection accuracy of the position information is deteriorated.

  On the other hand, as shown in FIG. 11A, in the image obtained by photographing the display panel 210 according to the first embodiment, the shadow of the lattice structure (pixel structure) by the black matrix 453 arranged in the color filter layer 451 is not superimposed. And the contrast of a dot pattern is good. This is because the light received by the digital pen 300 is dominated by the reflected light from the infrared reflection sheet 430 rather than the reflected light from the liquid crystal panel 450. As a result, the reflected light from the liquid crystal panel 450 becomes relatively weak, and the lattice structure (pixel structure) formed by the black matrix 453 becomes difficult to see. Thereby, the contrast of a dot pattern can be ensured and the detection accuracy of position information can be improved.

  Further, decoding processing for specifying position coordinates was performed using the images of FIGS. 11A and 11B. At this time, in order to decode the image shown in FIG. 11B, an image processing process for removing at least the shadow of the black matrix 453 is required. On the other hand, in order to decode the image shown in FIG. 11A, an image processing process for removing the shadow of the black matrix 453 is unnecessary, and the time required for the image processing can be reduced by 10%. Furthermore, the number of effective detection dots used in the decoding process for specifying the position coordinates has increased by 10%. Thereby, even when the display device 200 is soiled, error correction can be performed with the increased number of effective detection dots, and even if there are several dots 411 that could not be read, the offset (shift) of the dots 411 that could not be read. The direction can be estimated accurately. In addition, the frequency of dot pattern reading errors by the digital pen 300 can be greatly reduced.

[4. Effect]
As described above, the display panel 210 according to the first embodiment is the display panel 210 that forms the display control system 100 together with the digital pen 300. The digital pen 300 includes an illumination unit 380 that emits infrared light, an image sensor 350 that receives infrared light emitted from the illumination unit 380 and reflected by the display panel 210, and an image. A pen-side microcomputer 360 that specifies position information that the digital pen 300 points on the display panel 210 based on infrared light received by the sensor 350. On the other hand, the display panel 210 has a color filter layer on which a dot pattern sheet 410 formed according to a predetermined rule and a color filter 452 partitioned by a black matrix 453 are arranged in order to specify position information by the digital pen 300. 451 and an infrared reflection sheet 430 having an optical property of reflecting infrared light emitted from the digital pen 300. The infrared reflection sheet 430 is disposed between the dot pattern sheet 410 and the color filter layer 451.

  Thereby, it is possible to avoid the shadow of the lattice structure by the black matrix 453 being superimposed on the received light image of the position information pattern read by the digital pen 300, and to decode the position coordinates more accurately.

  In addition, the infrared reflection sheet 430 has an optical characteristic in which the amount of reflected light is larger than the amount of reflected infrared light transmitted through the color filter layer 451 partitioned by the black matrix 453. As a result, the position coordinates can be decoded with higher accuracy.

  In addition, the refractive index of the dot 411 and the refractive index of the dot flattening layer 413 are substantially the same, and the refractive index of the transparent adhesive layer 431 and the refractive index of the concavo-convex base material 433 are substantially the same. The influence can be reduced.

  As described above, the first embodiment has been described as an example of the technique disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed.

  Accordingly, among the components described in the attached drawings and detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to exemplify the above technique. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

  Moreover, since the above-mentioned embodiment is for demonstrating the technique in this indication, a various change, replacement, addition, abbreviation, etc. can be performed in a claim or its equivalent range.

  The present disclosure can be applied to a reading apparatus capable of forming a display panel and a display control system.

DESCRIPTION OF SYMBOLS 100 Display control system 200 Display apparatus 210 Display panel 230 Reception part 240 Display side microcomputer 250 Display apparatus side memory 300 Digital pen 310 Main body case 320 Pen tip part 330 Pressure sensor 340 Objective lens 350 Image sensor 360 Pen side microcomputer 370 Transmission part 380 Illumination 390 Pen side memory 400a Optical film 410 Dot pattern sheet 411 Dot 412 PET film 413 Dot flattening layer 414 First reference line 415 Second reference line 430 Infrared reflecting sheet 431 Transparent adhesive layer 432 Infrared reflecting layer 433 Uneven base material 440 Touch sensor glass 450 Liquid crystal panel 451 Color filter layer 452 Color filter 453 Black matrix 460 Backlight device 500 Diffuse reflection measuring device 5 0 Probe 600 standard reflector 610 completely diffusing surface 700 display panel

Claims (5)

A display panel that can use an optical pen that emits invisible light and receives reflected invisible light,
A position information pattern layer having a pattern for causing the optical pen to specify a position on the display panel;
A color filter layer including a color filter partitioned by a lattice structure;
A non-visible light reflection layer having a shape that diffusely reflects a part of the non-visible light emitted from the optical pen, and
The invisible light reflecting layer is disposed between the position information pattern layer and the color filter layer, and the amount of light reflected by the invisible light reflecting layer and incident on the optical pen is determined by the color filter layer. A display panel having a larger light amount than the amount of light that is reflected after being transmitted and incident on the optical pen through the invisible light reflection layer.   The display panel according to claim 1, wherein the shape is an uneven shape.   The invisible light reflection layer has a base material and a concavo-convex shape reflection layer, and the position information pattern layer is laminated via an adhesive layer, and the refractive index of the base material and the refractive index of the adhesive layer are substantially the same. The display panel according to claim 1, which is the same.   The display panel according to claim 1, wherein the pattern absorbs infrared rays. A display control system including an optical pen and a display panel,
The optical pen is
An emission part for emitting invisible light;
A light receiving portion for receiving invisible light;
A coordinate specifying unit that specifies position information that the optical pen points on the display panel based on the invisible light received by the light receiving unit;
The display panel is
A position information pattern layer having a pattern for causing the optical pen to specify a position on the display panel;
A color filter layer including a color filter partitioned by a lattice structure;
A non-visible light reflecting layer having a shape that diffusely reflects at least part of the invisible light emitted from the optical pen,
The invisible light reflecting layer is disposed between the position information pattern layer and the color filter layer, and the amount of light reflected by the invisible light reflecting layer and incident on the optical pen is determined by the color filter layer. A display control system in which the amount of light is larger than the amount of light that is reflected after being transmitted and is incident on the optical pen through the invisible light reflecting layer.