Display device and method for manufacturing the same

Abstract

The present invention provides a display device that forms grooves in a thin light guide member to separate optical paths, reducing the leakage of visible light to adjacent optical paths. A first groove (26) is formed in a first main surface (21) of the light guide member (20). A decorative layer (40) is integrally formed with the light guide member (20) and provided on a second main surface (22) of the light guide member (20). The decorative layer (40) has a first light-emitting portion (41) from which visible light irradiated from a first light-emitting element radiates from the light guide member (20) to the outside, and a second light-emitting portion (42) from which visible light irradiated from a second light-emitting element radiates from the light guide member (20) to the outside. A first light absorption member (51) is disposed on a first groove bottom (26b) of the first groove (26), and has a higher visible light absorption rate than the light guide member (20). The first groove (26) is disposed at a position that blocks the optical path from the first light-emitting element to a second region (AR2) and blocks the optical path from the second light-emitting element to a first region (AR1).

Description

Technical Field

[0001] The present invention relates to a display device and a method for manufacturing the display device, and particularly to a display device that guides visible light for display through a resin and a method for manufacturing the display device. Background Art

[0002] Conventionally, for example, as described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2008-129094), a display device combining a light guide plate and a display panel is known. In the light guide plate of Patent Document 1, in order to divide the optical paths from a plurality of LEDs (light emitting diodes) to the display panel into a plurality of paths, grooves are provided on the light guide plate.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2008-129094

[0006] In the case where the resin forming the light guide plate in Patent Document 1 becomes thick and the optical paths are separated by deep grooves, in the light guide plate, it is easy to reduce the leakage of visible light to adjacent optical paths.

[0007] However, if the light guide plate becomes thin, in order to maintain the strength of the light guide plate, the ratio of the depth of the groove to the thickness of the light guide plate cannot be increased. If the ratio of the depth of the groove to the thickness of the light guide plate cannot be increased, it is difficult to reduce the leakage of visible light to adjacent optical paths. Summary of the Invention

[0008] An object of the present invention is to reduce the leakage of visible light to adjacent optical paths in a display device in which grooves are formed on a thin light guide member to separate the optical paths.

[0009] Hereinafter, as means for solving the problems, a plurality of modes will be described. These modes can be arbitrarily combined as needed.

[0010] The display device according to one aspect of the present invention includes a resin light guide member that transmits visible light, a first light-emitting element, a second light-emitting element, a decorative layer, and a light absorption member. The light guide member has a first main surface and a second main surface facing the first main surface, and a first groove is formed in the first main surface. The first light-emitting element is disposed on the first main surface of the light guide member and is configured to irradiate visible light into the light guide member. The second light-emitting element is disposed on the first main surface or the second main surface of the light guide member and is configured to irradiate visible light into the light guide member. The decorative layer is integrally formed with the light guide member and is provided on at least one of the first main surface and the second main surface of the light guide member, and has a first light-emitting portion where visible light irradiated from the first light-emitting element radiates from the light guide member to the outside and a second light-emitting portion where visible light irradiated from the second light-emitting element radiates from the light guide member to the outside. The light absorption member is disposed on at least one of the first groove bottom of the first groove and the first groove facing portion of the second main surface facing the first groove bottom, and has a visible light absorption rate greater than that of the light guide member. The light guide member has a first region adjacent to one side surface of the first groove and a second region adjacent to the other side surface of the first groove. The first light-emitting element and the first light-emitting portion are disposed in the first region, and the second light-emitting element and the second light-emitting portion are disposed in the second region. The first groove is disposed at a position that blocks the optical path from the first light-emitting element toward the second region and blocks the optical path from the second light-emitting element toward the first region.

[0011] In the display device configured as described above, the optical path from the first light-emitting element toward the second region is blocked by the first groove, and moreover, the visible light irradiated from the first light-emitting element can be reduced from entering the second region through the gap between the first groove and the second main surface by the light absorption member. As a result, the visible light leaking from the optical path of the first light-emitting element to the optical path of the second light-emitting element can be reduced. Similarly, the optical path from the second light-emitting element toward the first region is blocked by the first groove, and moreover, the visible light irradiated from the second light-emitting element can be reduced from entering the first region through the gap between the first groove and the second main surface by the light absorption member. As a result, the visible light leaking from the optical path of the second light-emitting element to the optical path of the first light-emitting element can be reduced.

[0012] The above-described display device may also be configured such that the light absorption member is composed of rod-shaped members, and the rod-shaped members are arranged in a manner that they are in contact with the bottom of the first groove of the first groove and not in contact with the side surface of the first groove. In the display device configured in this way, the visible light leaking through the gap between the bottom of the first groove and the second main surface is reduced by the light absorption member. One side surface of the first groove can reflect the visible light in the first optical path toward the first optical path with less reduction without passing through the light absorption member, and the other side surface can reflect the visible light in the second optical path toward the second optical path with less reduction without passing through the light absorption member. As a result, even when the light absorption member is arranged in the first groove, it is possible to suppress a decrease in the brightness of the first light-emitting portion that emits light through the first light-emitting member, and it is possible to suppress a decrease in the brightness of the second light-emitting portion that emits light through the second light-emitting member.

[0013] The above-described display device may also be configured such that the depth of the first groove of the light guide member is smaller than the distance between the bottom of the first groove and the second main surface. Although the light guide member is thin in the display device configured in this way, it is difficult to break at the portion of the first groove.

[0014] In the above-described display device, it may also be configured such that the light guide member forms a second groove and a third groove on the first main surface in addition to the first groove, and the light absorption member is arranged on the bottom of the second groove of the second groove and the bottom of the third groove of the third groove, or is arranged on the second groove facing portion and the third groove facing portion of the second main surface facing the bottom of the second groove and the bottom of the third groove. The first groove and the second groove are arranged so as to sandwich the first region, and the first groove and the third groove are arranged so as to sandwich the second region. In the display device configured in this way, it is possible to reduce the visible light that bypasses from the second groove side and enters the first region by the second groove and the light absorption member. In addition, it is possible to reduce the visible light that bypasses from the third groove side and enters the second region by the third groove and the light absorption member. As a result, it is possible to suppress a decrease in the contrast between light and dark of the first light-emitting portion when the first light-emitting element emits light and when it does not emit light by the second groove and the light absorption member. Similarly, it is possible to suppress a decrease in the contrast between light and dark of the second light-emitting portion when the second light-emitting element emits light and when it does not emit light by the third groove and the light absorption member.

[0015] The display device according to other aspects of the present invention includes a light guide member, a first light-emitting element, a second light-emitting element, and a decorative layer. The light guide member is made of a resin that transmits visible light, has a first main surface and a second main surface facing the first main surface, and a first groove is formed in the first main surface. The first light-emitting element is disposed on the first main surface of the light guide member and is configured to irradiate visible light into the light guide member. The second light-emitting element is disposed on the first main surface or the second main surface of the light guide member and is configured to irradiate visible light into the light guide member. The decorative layer is integrally formed with the light guide member and is provided on at least one of the first main surface and the second main surface of the light guide member, and has a first light-emitting portion where visible light irradiated from the first light-emitting element radiates from the light guide member to the outside and a second light-emitting portion where visible light irradiated from the second light-emitting element radiates from the light guide member to the outside. The light guide member has a first region in contact with one side surface of the first groove and a second region in contact with the other side surface of the first groove. The first light-emitting element and the first light-emitting portion are disposed in the first region, and the second light-emitting element and the second light-emitting portion are disposed in the second region. At least a part of the first light-emitting element is disposed in a recess of the light guide member so as to be located between the first main surface and the second main surface of the light guide member. At least a part of the second light-emitting element is disposed in a recess of the light guide member so as to be located between the first main surface and the second main surface of the light guide member. The first groove is disposed at a position that blocks the optical path from the first light-emitting element toward the second region and blocks the optical path from the second light-emitting element toward the first region.

[0016] In the display device configured as described above, the optical path from the first light-emitting element toward the second region and the optical path from the second light-emitting element toward the first region are blocked by the first groove. Since at least a part of the first light-emitting element and the second light-emitting element can be disposed in the recess of the light guide member, the thickness of the light guide member can be reduced, and the distance between the first light-emitting element and the first light-emitting portion and the distance between the second light-emitting element and the second light-emitting portion can be shortened, and the visible light leaking from the optical path of the first light-emitting element to the optical path of the second light-emitting element and the visible light leaking from the optical path of the second light-emitting element to the optical path of the first light-emitting element can be reduced.

[0017] The above-described display device may also be configured to include a circuit film having a wiring pattern for electrically connecting the first light-emitting element and the second light-emitting element, disposed on the first main surface of the light guide member and integrally formed with the light guide member. In the display device configured in this way, it is easy to reduce the thickness of the display device in the direction from the first main surface toward the second main surface.

[0018] In the above-described display device, it may also be configured such that the decorative layer has a metal layer or a low-refractive-index layer in a portion facing the first region and the second region. In the display device configured in this way, diffusion of visible light in the first region and the second region can be suppressed, thereby suppressing a decrease in the brightness of the first light-emitting portion and the second light-emitting portion.

[0019] A method for manufacturing a display device according to one aspect of the present invention includes a molding step, a component setting step, a groove forming step, and a light absorption component setting step. In the molding step, a circuit film is integrally molded on a first main surface of a resin light guide member that transmits visible light, and a decorative layer is integrally molded on a second main surface of the light guide member. In the component setting step, the first light-emitting element and the second light-emitting element are arranged so as to be electrically connected to the circuit film and enable the first light-emitting element and the second light-emitting element to irradiate visible light into the light guide member. In the groove forming step, the first main surface of the light guide member is cut to form a first groove passing between the first light-emitting element and the second light-emitting element. In the light absorption component setting step, a light absorption component having a higher visible light absorption rate than the light guide member is provided in at least one of a first groove bottom of the first groove and a first groove facing portion on the second main surface facing the first groove bottom. The display device is manufactured such that the decorative layer has a first light-emitting portion and a second light-emitting portion. The first light-emitting portion is a portion where visible light irradiated from the first light-emitting element radiates from the light guide member to the outside. The second light-emitting portion is a portion where visible light irradiated from the second light-emitting element radiates from the light guide member to the outside. The display device is manufactured such that the light guide member has a first region and a second region. In the method for manufacturing the display device, the first region is in contact with one side surface of the first groove, and the first light-emitting element and the first light-emitting portion are arranged in the first region. In addition, the second region is in contact with the other side surface of the first groove, and the second light-emitting element and the second light-emitting portion are arranged in the second region. Further, the first groove is arranged at a position that blocks the optical path from the first light-emitting element toward the second region and blocks the optical path from the second light-emitting element toward the first region.

[0020] In the method for manufacturing a display device configured in this way, a display device can be obtained in which the optical path from the first light-emitting element toward the second region is blocked by the first groove, and visible light irradiated from the first light-emitting element entering the second region through the gap between the first groove and the second main surface can be reduced by the light absorption component. As a result, a display device can be obtained that can reduce visible light leaking from the optical path of the first light-emitting element to the optical path of the second light-emitting element. In the method for manufacturing a display device configured in this way, since the first groove is formed by cutting after the molding of the light guide member, a display device can be provided that prevents resin sink marks generated when forming a groove during molding and has less deformation of the decorative layer.

[0021] In the method for manufacturing the above-described display device, the molding step and the element setting step may also be implemented as follows: after electrically connecting the first light-emitting element and the second light-emitting element to the circuit film, the circuit film is insert-molded and the decorative layer is in-molded. In the method for manufacturing the display device configured in this way, it is possible to easily set the first light-emitting element and the second light-emitting element in the light guide member.

[0022] Advantages of the Invention

[0023] According to the display device and the method for manufacturing the same according to the present invention, it is possible to provide a display device in which even when a thin light guide member is provided, leakage of visible light to adjacent optical paths is less. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a perspective view of a center console to which the display device is applied.

[0025] Figure 2 is a view showing Figure 1 a state in which a portable telephone is filled in the center console.

[0026] Figure 3 is a view showing Figure 1 a cross-sectional view of the positional relationship among the display device, the console box, and the portable telephone.

[0027] Figure 4 is Figure 1 a perspective view of the display device shown in

[0028] Figure 5 is a view showing a cross-section of the display device along the I-I line of Figure 4

[0029] Figure 6 is a view showing a cross-section of the display device along the II-II line of Figure 4

[0030] Figure 7 is a perspective view of a model for a simulation experiment.

[0031] Figure 8 is a view for explaining a state of light leakage in the case where there is no groove.

[0032] Figure 9 is a view for explaining a state of light leakage of 5% or less in the case where there is a groove.

[0033] Figure 10 is a graph showing the relationship between the groove width and the light leakage when the visible light absorption rate of the light absorption member is 90%.

[0034] Figure 11 ​​A graph showing the relationship between the groove width and light leakage when the visible light absorption rate of the light absorption component is 70%.

[0035] Figure 12 A graph showing the relationship between the distance from the groove bottom to the second main surface and the coefficient α.

[0036] Figure 13 A graph showing the relationship between the distance from the groove bottom to the second main surface and the coefficient β.

[0037] Figure 14 A cross-sectional view showing the cross-section of the display device according to the second embodiment.

[0038] Figure 15 A cross-sectional view showing another cross-section of the display device according to the second embodiment.

[0039] Figure 16 (a) is a cross-sectional view showing the first groove with a rectangular cross-sectional shape. Figure 16 (b) is a cross-sectional view showing the first groove with a trapezoidal cross-sectional shape. Figure 16 (c) is a cross-sectional view showing the first groove with a polygonal cross-sectional shape. Figure 16 (d) is a cross-sectional view showing the first groove with a curved surface concave inward on the side. Figure 16 (e) is a cross-sectional view showing the first groove with a curved surface convex inward on the side.

[0040] Figure 17 A cross-sectional view showing the cross-section of the display device according to the modified example F.

[0041] Figure 18 A cross-sectional view showing another cross-section of the display device according to the modified example F.

[0042] Figure 19 A cross-sectional view showing the cross-section of the display device according to the modified example G.

[0043] Figure 20 A cross-sectional view showing the cross-section of the display device according to the modified example H.

[0044] Figure 21 A cross-sectional view showing the cross-section of the display device according to the modified example I.

[0045] Figure 22 A cross-sectional view for explaining the concave portion of the light guide member of the first and second embodiments.

[0046] Figure 23 A perspective view for explaining the concave portion of the light guide member according to the modified example J.

[0047] Symbol Explanation

[0048] 10 Display device

[0049] 20 Light guide member

[0050] 21 First main surface

[0051] 22 Second main surface

[0052] 26 First groove

[0053] 26b First groove bottom

[0054] 26s~28s Side surface

[0055] 27 Second groove

[0056] 27b Second groove bottom

[0057] 28 Third groove

[0058] 28b Third groove bottom

[0059] 31 First LED (example of first display element)

[0060] 32 Second LED (example of second display element)

[0061] 40 Decorative layer

[0062] 41 First light-emitting part

[0063] 42 Second light-emitting part

[0064] 51 First light absorption member

[0065] 52 Second light absorption member

[0066] 53 Third light absorption member

[0067] 60 Circuit film

[0068] 62 Wiring pattern

[0069] 71 First light absorption layer (example of light absorption member)

[0070] 72 Second light absorption layer (example of light absorption member)

[0071] 73 Third light absorption layer (example of light absorption member)

[0072] 80 Metal layer

[0073] PA1 First groove facing part

[0074] PA2 Second groove facing part

[0075] PA3 Third groove facing part Detailed implementation manners

[0076] <First implementation manner>

[0077] (1) Outline of the display device

[0078] (1-1) Outline of the display device

[0079] Figure 1 、 Figure 2 and Figure 3 The display device 10 mounted on the center console 200 of an automobile is described in Figure 2 and Figure 3 . The center console 200 has a function of charging the portable telephone 300 shown in

[0080] Figure 3 . A charging coil 220 that generates magnetic flux is arranged in the console box 210 of the center console 200. As a method for efficiently charging the portable telephone 300, increasing the ratio of the magnetic flux passing through the portable telephone 300 in the magnetic flux generated by the charging coil 220 is considered. Since the magnetic flux generated in the charging coil 220 diverges as it moves away from the charging coil 220, bringing the portable telephone 300 closer to the charging coil 220 involves increasing the ratio of the magnetic flux passing through the portable telephone 300. In addition, the charging coil 220 receives a supply of current for generating magnetic flux from a power source (not shown), for example. Figure 3 The cross-section of the center console 200 at the place where the portable telephone 300 is placed is shown in

[0081] Figure 1 . As shown in Figure 1 , a second icon 12 is displayed on the display device 10 in the state where the portable telephone 300 is not placed on the display device 10. The second icon 12 is an icon for notifying the placement position for charging the portable telephone 300.

[0082] Figure 2 The center console 200 in the state where the portable telephone 300 is placed on the display device 10 is shown in Figure 2In the display device 10 in the state shown, a first icon 11 and a third icon 13 are displayed. The third icon 13 is an icon for notifying that the charging of the mobile phone 300 is in progress. The first icon 11 is an icon for notifying the degree of charging of the mobile phone 300. For example, when the first icon 11 is lit, the user can know that the charging of the mobile phone 300 has been completed.

[0083] In order to detect the placed mobile phone 300, for example, a detection device (not shown) is arranged in the console box 210. The display device 10, the charging coil 220, the power supply, and the detection device are connected to the control device 230. Before the mobile phone 300 is placed on the display device 10, as Figure 1 shown, the control device 230 performs control to cause the display device 10 to display the second icon 12. When the mobile phone 300 is placed on the display device 10, the control device 230 receives information related to the detection of the placed mobile phone 300 from the detection device. The control device 230 supplies current from the power supply to the charging coil 220 when the mobile phone 300 is placed, and at the same time, performs control to stop the display of the second icon 12 on the display device 10 and display the third icon 13. Then, when the battery of the mobile phone 300 is in a fully charged state, control is performed to cause the display device 10 to display the first icon 11. In order to perform such control, the control device 230 is connected to the display device 10.

[0084] (1-2) Structure of the display device

[0085] Figure 4 The state of observing the display device 10 from obliquely above is shown. In addition, in Figure 4 the description of parts other than the icons of the decorative layer is omitted. In Figure 5 a part of the cross-section of the display device 10 cut along the I-I line in Figure 4 is shown in an enlarged manner. In Figure 6 a part of the cross-section of the display device 10 cut along the II-II line in Figure 4 is shown in an enlarged manner. In addition, when explaining the structure of the display device 10, the orthogonal coordinates shown in Figure 4 are sometimes used.

[0086] As Figure 3 and Figure 4 shown, the display device 10 includes a light guide member 20, a first LED 31, a second LED 32, a third LED 33, a decorative layer 40, a first light absorption member 51, a second light absorption member 52, a third light absorption member 53, and a fourth light absorption member 54. In addition, hereinafter, the first LED 31 will be described as an example of the first light emitting element, and the second LED 32 will be described as an example of the second light emitting element.

[0087] (1-2-1) Light guide member

[0088] The light guide member 20 is a member made of a resin that transmits visible light. Examples of the thermoplastic resin used for the light guide member 20 include polycarbonate resin, acrylic resin, and ABS resin. The light guide member 20 is a plate-like member for guiding visible light from the first LED 31, the second LED 32, and the third LED 33. The light guide member 20 has a first main surface 21 and a second main surface 22. The thickness of the light guide member 20 is, for example, 5 mm or less, preferably 2.5 mm or less.

[0089] A decorative layer 40 is provided on the second main surface 22 of the light guide member 20. The first LED 31, the second LED 32, and the third LED 33 are arranged on the first main surface 21 of the light guide member 20. When arranged on the first main surface 21 of the light guide member 20, the entire LED is deeply embedded, including the case where the entire LED does not reach the first main surface 21 in the cross-sectional view. The first LED 31, the second LED 32, and the third LED 33 are embedded in the light guide member 20. Therefore, at least a part of the first LED 31, the second LED 32, and the third LED 33 is located between the first main surface 21 and the second main surface 22. Therefore, in the present embodiment, the first LED 31, the second LED 32, and the third LED 33 are integrally formed with the light guide member 20 simultaneously with the decorative layer 40, and the entire first LED 31, the second LED 32, and the third LED 33 are embedded in the light guide member 20. The place for the entire first LED 31, the second LED 32, and the third LED 33 to be embedded becomes the recess of the light guide member 20.

[0090] A first groove 26, a second groove 27, a third groove 28, and a fourth groove 29 are formed on the first main surface 21 of the light guide member 20. The first groove 26 to the fourth groove 29 each extend linearly in the Y-axis direction. The cross-sectional shape of the first groove 26 to the fourth groove 29 cut along the XZ plane is a rectangle. As Figure 3 shown, the first groove 26 to the fourth groove 29 each have a first groove bottom 26b, a second groove bottom 27b, a third groove bottom 28b, and a fourth groove bottom 29b. In addition, as Figure 5 shown, the first groove 26 has two side surfaces 26s that stand up from both sides of the first groove bottom 26b extending in the Y-axis direction. Similarly, the second groove 27 and the third groove 28 have side surfaces 27s and 28s that stand up from both sides of the second groove bottom 27b and the third groove bottom 28b extending in the Y-axis direction. Here, the case where the first groove 26 to the fourth groove 29 each extend linearly in the Y-axis direction has been described, but the first groove 26 to the fourth groove 29 may each extend in a curved shape in the Y-axis direction. In addition, the cross-sectional shape of the first groove 26 to the fourth groove 29 cut along the XZ plane is not limited to a rectangle.

[0091] As Figure 4 , Figure 5 and Figure 6 shown, the light guide member 20 has a first region AR1 and a second region AR2. The first region AR1 is a region that abuts against one side surface 26s of the first groove 26. The second region AR2 is a region that abuts against the other side surface 26s of the first groove 26. In other words, the first region AR1, the first groove 26, and the second region AR2 are arranged in sequence along the X-axis direction. The range of the first region AR1 in the X-axis direction is from the side surface 26s of the first groove 26 to the side surface 27s of the second groove 27. The range of the second region AR2 in the X-axis direction is from the side surface 26s of the first groove 26 to the side surface 28s of the third groove 28. The range of the first region AR1 and the second region AR2 in the Y-axis direction is from one end to the other end of the first groove 26. In other words, the length of the first region AR1 and the second region AR2 in the Y-axis direction is equivalent to the length of the first groove 26. The first groove 26 is disposed at a position that blocks the optical path from the first LED 31 toward the second region AR2 and blocks the optical path from the second LED 32 toward the first region AR1. By the first groove 26 configured in this way, the visible light from the first LED 31 toward the second region AR2 is reduced, and the visible light from the second LED 32 toward the first region AR1 is reduced.

[0092] (1-2-2) First LED to Third LED

[0093] The first LED 31, the second LED 32, and the third LED 33 are configured to be able to irradiate visible light into the light guide member 20. The first LED 31, the second LED 32, and the third LED 33 of this embodiment are embedded into the light guide member 20 by insert molding so as not to protrude from the first main surface 21 of the light guide member 20. The insert molding of the first LED 31, the second LED 32, and the third LED 33 will be described later. The visible light irradiated from the first LED 31 causes the first icon 11 to emit light through the first optical path OP1 of the light guide member 20. The visible light irradiated from the second LED 32 causes the second icon 12 to emit light through the second optical path OP2 of the light guide member 20. The visible light irradiated from the third LED 33 causes the third icon 13 to emit light through the third optical path OP3 of the light guide member 20. The first LED 31, the second LED 32, and the third LED 33 can use chip LEDs, for example. The thickness of the chip LED is, for example, 0.4 mm to 2 mm. The chip LED is, for example, rectangular in plan view and has a size of 1.6 mm × 0.8 mm to 3.5 mm × 2.8 mm.

[0094] (1-2-3) Decorative layer

[0095] The decorative layer 40 is integrally formed with the light guide member 20. The decorative layer 40 is integrated with the decorative film and the light guide member 20 by insert molding, and thus is integrally formed with the light guide member 20. Alternatively, the decorative layer 40 is transferred onto the light guide member 20 by in-mold molding, and thus is integrally formed with the light guide member 20 (forming step). Here, the case where the decorative layer 40 is transferred and formed by in-mold molding is exemplified, but the decorative layer may also be transferred after molding.

[0096] The decorative layer 40 has a first light-emitting portion 41, a second light-emitting portion 42, and a third light-emitting portion 43. The first light-emitting portion 41 is a portion that radiates visible light irradiated from the first LED 31 to the outside from the light guide member 20. The first icon 11 is formed on the first light-emitting portion 41. The first icon 11 is displayed by radiating visible light irradiated from the first LED 31 to the outside from the first light-emitting portion 41. The second icon 12 is formed on the second light-emitting portion 42, and the third icon 13 is formed on the third light-emitting portion 43. The second icon 12 is displayed by radiating visible light irradiated from the second LED 32 to the outside from the second light-emitting portion 42, and the third icon 13 is displayed by radiating visible light irradiated from the third LED 33 to the outside from the third light-emitting portion 43.

[0097] The decorative layer 40 may be composed of, for example, a light-transmissive film that transmits visible light, a shielding layer formed on the light-transmissive film to block visible light, and a pattern layer formed on the shielding layer. The light-transmissive film is a transparent resin film having a thickness of, for example, 10 μm to 500 μm. The light-transmissive film is selected from, for example, polyester resin, polyethylene terephthalate (PET) resin, acrylic resin, polycarbonate resin, polybutylene terephthalate (PBT) resin, triacetyl cellulose resin, a resin film composed of styrene resin or ABS resin, a multilayer film of acrylic resin and ABS resin, or a multilayer film of acrylic resin and polycarbonate resin. The shielding layer is formed in a place other than the first light-emitting portion 41, the second light-emitting portion 42, and the third light-emitting portion 43 where visible light radiates from the light guide member 20 to the outside. The shielding layer is formed on the light-transmissive film by, for example, gravure printing or screen printing. The material constituting the shielding layer includes, for example, resins such as acrylic resin, vinyl chloride-vinyl acetate copolymer resin, thermoplastic polyurethane resin, and polyester resin, and pigments or dyes added to the resin.

[0098] The pattern layer is a layer for expressing designs such as patterns. For example, the first icon 11, the second icon 12, and the third icon 13 are drawn through the pattern layer. The pattern layer is formed on the base film by, for example, gravure printing or screen printing. The materials constituting the pattern layer include, for example, resins such as acrylic resins, vinyl chloride-vinyl acetate copolymer resins, thermoplastic polyurethane resins, and polyester resins, as well as pigments or dyes added to the resins. In addition, for the pattern layer, a metallic style design can be implemented using, for example, printing or metal evaporation. In the printing method, for example, aluminum paste or mirror ink can be used. In addition, in the metal evaporation method, for example, metallic materials such as aluminum, tin, indium, or chromium can be used. In addition, a coating for protecting the pattern layer can also be provided on the pattern layer on the side opposite to the base film.

[0099] In the case where the decorative layer 40 is formed by transfer, the decorative layer 40 has, for example, a shielding layer and a pattern layer that remove the light-transmissive film.

[0100] The decorative layer 40 is bonded and fixed to the light guide member 20 by, for example, a light-transmissive adhesive.

[0101] (1-2-4) Light absorption member

[0102] As Figure 4 , Figure 5 and Figure 6 shown, the first light absorption member 51 is provided in the first groove 26 (light absorption member setting step). The first light absorption member 51 is fixed to the first groove bottom 26b of the first groove 26 by, for example, an adhesive. Similarly, the second light absorption member 52 to the fourth light absorption member 54 are respectively arranged in the second groove 27 to the fourth groove 29. The first light absorption member 51 to the fourth light absorption member 54 are all rectangular parallelepiped-shaped rod members. However, the shapes of the first light absorption member 51 to the fourth light absorption member 54 are not limited to rectangular parallelepipeds, as long as they can be arranged in the first groove 26 to the fourth groove 29.

[0103] In the first light absorption member 51 to the fourth light absorption member 54, the visible light absorption rate is preferably 70% or more, and more preferably 90% or more.

[0104] Here, when light is perpendicularly incident on a light absorption member with a thickness of 1 mm, the visible light absorption rate ab [%] is expressed by the following formula, where the reflectance is set as re [%] and the transmittance is set as tr [%].

[0105] ab = 100 - re - tr

[0106] When the absorption rate is ab, the wavelength of the incident light is in the visible light region (380 nm to 780 nm). For example, when the absorption rate is 70% or more, it only needs to be 70% or more in the entire visible light region.

[0107] The first light absorption member 51 to the fourth light absorption member 54 can be formed, for example, by injection molding a resin added with a black pigment. The resin forming the first light absorption member 51 to the fourth light absorption member 54 is constituted by, for example, the same resin as the resin constituting the light guide member 20.

[0108] (2) Method of forming the grooves

[0109] As already described, the decorative layer 40 formed simultaneously during the injection molding of the light guide member 20 is disposed on the second main surface 22 of the light guide member 20. During this injection molding, the first groove 26 to the fourth groove 29 are not formed on the light guide member 20. The first groove 26 to the fourth groove 29 are formed, for example, by mechanically cutting the first main surface 21 (groove forming step). Thus, by forming the first groove 26 to the fourth groove 29 after the injection molding, it is possible to prevent sink marks from occurring on the second main surface 22 of the light guide member 20. By forming the first groove 26 to the fourth groove 29 after the injection molding, a beautiful decorative layer 40 can be obtained.

[0110] (3) Method of setting the LEDs

[0111] In the present embodiment, the first LED 31, the second LED 32, and the third LED 33 are electrically connected to the control device 230. For the electrical connection of the first LED 31, the second LED 32, and the third LED 33, the display device 10 includes a circuit film 60. The circuit film 60 is configured to include a resin film 61 and a wiring pattern 62 formed on the resin film 61 (see Figure 4 and Figure 5 ). The circuit film 60 and the control device 230 are connected, for example, using a flexible printed circuit board (not shown). The flexible printed circuit board and the wiring pattern 62 are connected, for example, using an anisotropic conductive film (not shown). The first LED 31, the second LED 32, and the third LED 33 and the wiring pattern 62 are connected, for example, using a conductive adhesive (element setting step).

[0112] The circuit film 60 is preferably insert-molded during the injection molding of the light guide member 20. By insert-molding the circuit film 60 to which the first LED 31, the second LED 32, and the third LED 33 are electrically connected, the first LED 31, the second LED 32, and the third LED 33 can be set in the light guide member 20 at the same time during molding. In addition, the circuit film 60 is not disposed at the portion where the first groove 26 to the fourth groove 29 are formed.

[0113] (4) Method of forming the optical path

[0114] As described above, the first optical path OP1 to the third optical path OP3 are formed by forming the first groove 26 to the fourth groove 29 on the first main surface 21 of the light guide member 20. The first optical path OP1 is formed between the first groove 26 and the second groove 27, the second optical path OP2 is formed between the first groove 26 and the third groove 28, and the third optical path OP3 is formed between the third groove 28 and the fourth groove 29.

[0115] A decorative layer 40 is formed on the second main surface 22 of the light guide member 20 where the first optical path OP1 to the third optical path OP3 are formed. In order to suppress the attenuation of visible light transmitted through the first optical path OP1 to the third optical path OP3 by the decorative layer 40, the decorative layer 40 has a metal layer, a low refractive index layer for causing total reflection, or irregularities for causing total reflection at the portions constituting the first optical path OP1 to the third optical path OP3. For example, when a normal ink layer such as white is provided at the portions constituting the first optical path OP1 to the third optical path OP3, the visible light diffuses through the ink layer and the brightness decreases.

[0116] (5) Shape of the groove

[0117] The width and depth of the groove are quantified through the following light leakage simulation experiment. Figure 7 The model of the simulation experiment shown is a display device 10 in which icons of 10 mm × 10 mm are arranged at intervals of 10 mm.

[0118] Figure 7 The planar shape of the light guide member 20 shown is a square of 100 mm × 100 mm, and the thickness D is 1.5 mm or 2.5 mm.

[0119] The light leakage ratio L is defined by the following formula (1). However, the icon IC1 is an icon to be displayed by the first light emitting element Em composed of an LED, and the icon IC2 is an icon arranged on the opposite side of the icon IC1 with the first groove Gr1 and the first light absorption member AB1 interposed therebetween. L = (average illuminance of the icon IC1) / (average illuminance of the icon IC2) × 100 ··· (1)

[0120] As Figure 7 shown, the evaluation surface ES for evaluating the illuminance of the icon is provided directly above the display device 10. The average illuminance of the evaluation surface ES is calculated through a simulation experiment. Even when the thickness D of the light guide member 20 of the display device 10 is either 1.5 mm or 2.5 mm, the evaluation surface ES is arranged at a position 2.51 mm away from the bottom surface (the first main surface 21) of the light guide member 20.

[0121] For example, under the conditions where the thickness of the light guide member 20 is 1.5 mm, the width W of the first groove Gr1 is 3.0 mm, the plate thickness of the groove portion (the distance d from the groove bottom of the first groove Gr1 to the second main surface 22 of the light guide member 20) is 1.0 mm (the light guide member 20 is cut by 0.5 mm from the first main surface 21 to set d = 1.0 mm), the first light absorption member AB1 is black, the visible light absorption rate is 90%, and the visible light reflectance is 10%, in the simulation experiment results without grooves, the light leakage L is about 26%, and in the simulation experiment results with the first groove Gr1 and the first light absorption member AB1, the light leakage L is about 4%. In Figure 8 shows the simulation experiment results without grooves. In Figure 9 shows the simulation experiment results with the first groove Gr1 and the first light absorption member AB1. Comparing Figure 8 and Figure 9 it can be seen that by suppressing the light leakage L to 5% or less, when the adjacent icon IC1 emits light, it is possible to suppress the user from visually recognizing the icon IC2 that does not emit light.

[0122] In addition, the first light absorption member AB1 is in contact with the entire groove bottom of the first groove Gr1 and is not in contact with the side surface of the first groove Gr1. In addition, other grooves such as the second groove Gr2 and the third groove Gr3 are also set to have the same shape as the first groove Gr1, and other light absorption members such as the second light absorption member AB2 and the third light absorption member AB3 are also set to the same conditions as the first light absorption member AB1.

[0123] Figure 10 shows the simulation experiment results when the visible light absorption rate of the first light absorption member AB1 is 90% and the thickness D of the light guide member 20 is 1.5 mm. In Figure 10 approximate curve Ln1 represents the relationship between the light leakage and the groove width W when the distance d from the groove bottom of the first groove Gr1 to the second main surface 22 of the light guide member 20 is 0.5 mm. Approximate curve Ln2 represents the relationship between the light leakage and the groove width W when the distance d is 0.75 mm. Approximate curve Ln3 represents the relationship between the light leakage and the groove width W when the distance d is 1.0 mm.

[0124] When the plate thickness of the groove portion (distance d) is 0.5 mm, the approximate curve Ln1 satisfies the relationship of formula (2), when the plate thickness of the groove portion (distance d) is 0.75 mm, the approximate curve Ln2 satisfies the relationship of formula (3), and when the plate thickness of the groove portion (distance d) is 1.0 mm, the approximate curve Ln3 satisfies the relationship of formula (4).

[0125] L = 4.15W -1.20 ···(2)

[0126] L = 7.51W -1.07 ···(3)

[0127] L = 11.46W -0.96 ···(4)

[0128] The light leakage L utilization coefficients α and β are expressed by the following formula (5).

[0129] L = αW β ···(5)

[0130] Since α and β vary linearly with respect to the distance d (the plate thickness of the groove part), the following formula (6) is derived.

[0131] L = (1.46d + 3.25)W 0.474d-1.43 ···(6)

[0132] When suppressing the light leakage to 5% or less, satisfying the relationship of the following formula (7) becomes a goal.

[0133] 5 ≥ (1.46d + 3.25)W 0.474d-1.43 ···(7)

[0134] Figure 11 The simulation experiment results are shown in the case where the visible light absorption rate of the first light absorption member AB1 is 70% and the thickness D of the light guide member 20 is 1.5 mm. In Figure 11 Among them, the approximate curve Ln4 represents the relationship between the light leakage and the groove width W when the distance d from the bottom of the first groove Gr1 to the second main surface 22 of the light guide member 20 is 0.5 mm. The approximate curve Ln5 represents the relationship between the light leakage and the groove width W when the distance d is 0.75 mm. The approximate curve Ln6 represents the relationship between the light leakage and the groove width W when the distance d is 1.0 mm.

[0135] When the plate thickness of the groove part (distance d) is 0.5 mm, the approximate curve Ln4 satisfies the relationship of formula (8). When the plate thickness of the groove part (distance d) is 0.75 mm, the approximate curve Ln5 satisfies the relationship of formula (9). When the plate thickness of the groove part (distance d) is 1.0 mm, the approximate curve Ln6 satisfies the relationship of formula (10).

[0136] L = 5.14W -1.06 ···(8)

[0137] L = 9.02W -0.892 ···(9)

[0138] L = 13.11W -0.767 ···(10)

[0139] The light leakage L use coefficients α and β are represented by the above formula (5).

[0140] As Figure 12 and Figure 13 shown, α and β vary linearly with respect to the distance d (the plate thickness of the groove portion), and thus the following formula (11) is derived.

[0141] L = (15.9d - 2.87)W 0.602d-1.36 ···(11)

[0142] When suppressing the light leakage to 5% or less, satisfying the relationship of the following formula (12) becomes a goal.

[0143] 5.00 ≥ (15.9d - 2.87)W 0.602d-1.36 ···(12)

[0144] <Second Embodiment>

[0145] (6) Outline of the display device

[0146] Regarding the display device 10 of the first embodiment, the case where the first light absorption member 51 to the fourth light absorption member 54 are arranged among the first groove 26 to the fourth groove 29, particularly among the first groove bottom 26b to the fourth groove bottom 29b, has been described. However, as Figure 14 and Figure 15 shown, the arrangement location of the light absorption member can also be the second main surface 22.

[0147] In Figure 14 and Figure 15 shown in the display device 10 of the second embodiment, the first light absorption layer 71, the second light absorption layer 72, and the third light absorption layer 73 are light absorption members. The first light absorption layer 71, the second light absorption layer 72, and the third light absorption layer 73 are formed on the decorative layer 40. The first light absorption layer 71 is arranged at the first groove facing portion PA1 on the second main surface 22 of the light guide member 20 facing the first groove bottom 26b. In addition, the second light absorption layer 72 and the third light absorption layer 73 are arranged at the second groove facing portion PA2 on the second main surface 22 facing the second groove bottom 27b and the third groove facing portion PA3 facing the third groove bottom 28b. The first light absorption layer 71, the second light absorption layer 72, and the third light absorption layer 73 are made of, for example, the same material as the first light absorption member 51, the second light absorption member 52, and the third light absorption member 53.

[0148] In addition, in the decorative layer 40, a metal layer 80 is provided in a first region AR1 and a second region AR2 other than the first light-emitting portion 41 and the second light-emitting portion 42. Here, the case where the decorative layer 40 has the metal layer 80 has been described, but instead of the metal layer 80, a low refractive index layer for causing total reflection may be provided.

[0149] (7) Variation

[0150] (7-1) Variation A

[0151] In the above first embodiment, the case where the first light absorption member 51 to the fourth light absorption member 54 are rod-shaped members has been described, but the first light absorption member 51 to the fourth light absorption member 54 are not limited to rod-shaped members. The first light absorption member 51 to the fourth light absorption member 54 may be, for example, black strip-shaped films. In addition, the first light absorption member 51 to the fourth light absorption member 54 may be, for example, black printed layers.

[0152] (7-2) Variation B

[0153] In the above first embodiment, the case where, for example, the first light absorption member 51 is formed on the first groove bottom 26b of the first groove 26 and no light absorption member is provided on the second main surface 22 of the light guide member 20 has been described. In addition, in the above second embodiment, the case where, for example, the first light absorption layer 71 is formed on the first groove facing portion PA1 of the second main surface 22 of the light guide member 20 and no light absorption member is provided on the first groove bottom 26b of the first groove 26 has been described. However, the light absorption member may be formed on both the first groove bottom 26b and the first groove facing portion PA1. Similarly, the light absorption member may be formed on both the second groove bottom 27b and the second groove facing portion PA2 and both the third groove bottom 28b and the third groove facing portion PA3.

[0154] (7-3) Variation C

[0155] In the above first embodiment and second embodiment, the case where the second main surface 22 of the light guide member 20 is a flat surface has been described. However, the second main surface 22 of the light guide member 20 is not limited to a flat surface. The second main surface 22 of the light guide member 20 may be, for example, a curved surface. The case where the second main surface 22 of the light guide member 20 is flat has been described, but the second main surface 22 of the light guide member 20 may also have irregularities.

[0156] (7-4) Variation D

[0157] In the above-described first and second embodiments, the case where the first groove 26 to the fourth groove 29 are formed by cutting the planar first main surface 21 of the light guide member 20 has been described. However, the first main surface 21 before the formation of the first groove 26 to the fourth groove 29 may not be planar but may be a curved surface.

[0158] (7-5) Variant E

[0159] In the above-described first and second embodiments, as Figure 16 shown in (a) of Figure 16 , in the light guide member 20, the case where the cross-sectional shape of, for example, the first groove 26 is rectangular has been described. In addition, Figure 16 the cross-sectional shape of the first groove 26 shown in (a) to Figure 4 (e) of

[0160] is the shape of a cross-section perpendicular to the long side direction ( Figure 16 the Y-axis direction of Figure 16 ) of the first groove 26. Figure 16 However, the cross-sectional shape of the groove formed in the light guide member 20 is not limited to rectangular. For example, as the first groove 26 shown in (b) of Figure 16 , it may also be a shape in which the side surface 26s is inclined. In other words, Figure 16 the cross-sectional shape of the first groove 26 shown in (b) of Figure 16 is trapezoidal. For example, as the first groove 26 shown in (c) of Figure 16 , it may be a broken line in which the cross-sectional shape of the side surface 26s is bent midway. In other words, Figure 16 the cross-sectional shape of the first groove 26 shown in (c) of Figure 16 is polygonal. Figure 16 The bottom 26b of the first groove in (c) of Figure 16 is a portion parallel to the second main surface 22. For example, as the first groove 26 shown in (d) of

[0161] (7-6) Variant F

[0162] In the above-described first embodiment, the first groove 26 to the fourth groove 29 are each formed by a single groove. However, the grooves such as the first groove to the fourth groove may also be formed by a plurality of grooves. Figure 17 And Figure 18The first groove 26 shown is composed of a main groove 26p and two sub-grooves 26q and 26r on both sides thereof. Similarly, the second groove 27 and the third groove 28 are respectively composed of a main groove 27p, 28p and two sub-grooves 27q, 27r, 28q, 28r. In each of the main grooves 26p, 27p, 28p, as Figure 17 and Figure 18 shown, a first light absorption member 51, a second light absorption member 52 and a third light absorption member 53 are formed. The first light absorption member 51, the second light absorption member 52 and the third light absorption member 53 reach the sides of the respective main grooves 26p, 27p, 28p. In such a structure, for example, the entire main grooves 26p, 27p, 28p can be filled with a member that absorbs visible light. As a method of filling the entire main grooves 26p, 27p, 28p, for example, there are the following methods: filling the entire main grooves 26p, 27p, 28p with a thermoplastic resin that absorbs visible light, or filling the entire main grooves 26p, 27p, 28p with a paint that absorbs visible light.

[0163] The side surface 26s of the first groove 26 becomes the side surface of the sub-groove 26q that abuts on the first region AR1 and the side surface of the sub-groove 26r that abuts on the second region AR2. Since no light absorption member is disposed in the sub-grooves 26q, 26r, visible light is not absorbed but reflected on the side surfaces 26s of the sub-grooves 26q, 26r. In the second groove 27 and the third groove 28, similarly, the side surfaces 27s, 28s for reflecting visible light are the side surfaces of the sub-grooves 27q, 27r, 28q, 28r.

[0164] (7-7) Variant G

[0165] In the above-described first embodiment and second embodiment, the first groove 26 to the fourth groove 29 are formed by mechanically cutting a resin plate that transmits visible light as the light guide member 20. However, the method of forming the groove is not limited to the method of mechanically cutting the resin plate. For example, as Figure 19 shown, the display device 10 may also be divided into an outer layer portion 110 on the front side and an inner layer portion 120 on the back side, and the outer layer portion 110 and the inner layer portion 120 may be bonded by an adhesive layer 130 that transmits visible light. The adhesive layer 130 that transmits visible light may use, for example, LOCA (Liquid Optically Clear Adhesives).

[0166] The outer layer portion 110 includes a resin layer 111 that transmits visible light and is made of a thermoplastic resin, and a decorative layer 40 that is integrally formed with the resin layer 111. The decorative layer 40 is integrally formed with the resin layer 111 by simultaneous decoration during molding. The thickness of the outer layer portion 110 is, for example, 1.0 mm to 2.0 mm.

[0167] The inner layer portion 120 includes a circuit film 60, a resin molding layer 121, a first light absorption member 51, a second light absorption member 52, and a third light absorption member 53. The circuit film 60, the resin molding layer 121, the first light absorption member 51, the second light absorption member 52, and the third light absorption member 53 are formed, for example, by insert molding in which the circuit film 60, the first light absorption member 51, the second light absorption member 52, and the third light absorption member 53 are embedded in the resin molding layer 121. The circuit film 60, the first light absorption member 51, the second light absorption member 52, and the third light absorption member 53 may be pre-bonded before insert molding or may be bonded during insert molding. In this case, the resin layer 111, the resin molding layer 121, and the bonding layer 130 constitute the light guide member 20. When the visible light emitted from the first LED 31 passes through the resin layer 111 and the bonding layer 130 and travels from the first optical path OP1 toward the second optical path OP2, it is absorbed by the first light absorption layer 71.

[0168] In addition, Figure 19 The first groove 26 to the fourth groove 29 shown are covered grooves, that is, dark grooves. The grooves such as the first groove, the second groove, and the third groove in the present application may also be dark grooves buried in the light guide member.

[0169] (7-8) Modification H

[0170] As a method of forming the first groove 26 to the fourth groove 29 described in the above first embodiment and second embodiment, as Figure 20 shown, it may also be formed by combining a plurality of resin blocks. Figure 20 The display device 10 shown includes an outer layer portion 110, a plurality of resin blocks 141, 142, 143, and a bonding layer 130 that transmits visible light. In this modification, similar to the second embodiment, a first light absorption layer 71, a second light absorption layer 72, and a third light absorption layer 73 are provided on the second main surface 22. In Figure 20In the display device 10 shown, a first optical path OP1 is provided in the resin block 141, and a second optical path OP2 is provided in the resin block 142. The first LED 31, which is a first light-emitting element, is embedded in the resin block 141. In addition, the second LED 32, which is a second light-emitting element, is embedded in the resin block 142. A first groove 26 is formed between the first resin block 141 and the second resin block 142. A second groove 27 is formed between the first resin block 141 and the third resin block 143. For example, in order to form the first groove 26, a protrusion 141a is provided on the first resin block 141, and a protrusion 142a is provided on the second resin block 142. The space where the protrusions 141a and 141b can be butted becomes the first groove 26. However, there are other methods for providing the first groove 26. For example, at the time of manufacturing the display device 10, a spacer (not shown) that forms the interval between the first resin block 141 and the second resin block 142 may be used. In this case, the spacer is removed after manufacturing. The first groove 26 is disposed in the first groove facing portion PA1, the second groove 27 is disposed in the second groove facing portion PA2, and the third groove 28 is disposed in the third groove facing portion PA3. For example, when the visible light irradiated from the first LED 31 passes through the resin layer 111 and the adhesive layer 130 and travels from the first optical path OP1 toward the second optical path OP2, it is absorbed by the first light absorption layer 71.

[0171] (7-9) Variant I

[0172] In the above-described first and second embodiments, both the first LED 31 and the second LED 32 are disposed on the first main surface 21 of the light guide member 20. However, the first light-emitting element may be disposed on the first main surface, and the second light-emitting element may be disposed on the second main surface. In Figure 21 the display device 10 shown, the first LED 31 is disposed on the first main surface 21 of the light guide member 20, and the second LED 32 is disposed on the second main surface 22 of the light guide member 20. In addition, although not shown, a first light-emitting portion that emits light through the first LED 31 is formed in the decorative layer 40 on the second main surface 22, and a second light-emitting portion that emits light through the second LED 32 is formed in the decorative layer 40 on the first main surface 21.

[0173] (7-10) Variant J

[0174] In the above-described first embodiment and second embodiment, the case where the first light absorption member 51 and the second light absorption member 52, or the first light absorption layer 71 and the second light absorption layer 72 are arranged in parallel on both sides of the first region AR1 where the first LED 31 is disposed has been described. However, the arrangement of the first light absorption member 51 and the second light absorption member 52, or the first light absorption layer 71 and the second light absorption layer 72 is not limited to such an arrangement. For example, they may be arranged so as to surround the entire circumference of the first region AR1 by the first light absorption member 51 and the second light absorption member 52, or the first light absorption layer 71 and the second light absorption layer 72. Such an arrangement of the light absorption member or the light absorption layer can be similarly performed in the second region AR2.

[0175] (7-11) Variant K

[0176] In the above-described first embodiment and second embodiment, during insert molding, as Figure 22 shown, the case where the recess 23 is formed in the light guide member 20 and the first LED 31 is disposed in the recess 23 has been described. However, the method of forming the recesses for disposing the first light-emitting element, the second light-emitting element, and the third light-emitting element is not limited to the above method. For example, as Figure 23 shown, the recess 23 may be formed in the light guide member 20 in advance, and then the circuit film 60 may be pasted so that the first LED 31 is disposed in the recess 23.

[0177] (8) Features

[0178] (8-1)

[0179] In the above-described display device 10, the optical path from the first LED 31 as the first light-emitting element toward the second region AR2 is blocked by the first groove 26. And, the visible light irradiated from the first LED 31 through the gap between the first groove 26 and the second main surface 22 of the light guide member 20 can be reduced from entering the second region AR2 by the first light absorption member 51 and / or the first light absorption layer 71. As a result, the visible light leaking from the first optical path OP1 of the first LED 31 to the second optical path OP2 of the second LED 32 can be reduced. Similarly, the optical path from the second LED 32 as the second light-emitting element toward the first region AR1 is blocked by the first groove 26. And, the visible light irradiated from the second LED 32 through the gap between the first groove 26 and the second main surface 22 of the light guide member 20 can be reduced from entering the first region AR1 by the first light absorption member 51 and / or the first light absorption layer 71. As a result, the visible light leaking from the second optical path OP2 of the second LED 32 to the first optical path OP1 of the first LED 31 can be reduced.

[0180] (8-2)

[0181] In the above-described display device 10, the first light absorption member 51 as the light absorption member is a rod-shaped member, and is arranged in such a manner that it is in contact with the first bottom 26b of the first groove 26 and is not in contact with the side surface 26s of the first groove 26. In such a display device 10, the first light absorption member 51 reduces the visible light leaking through the gap between the first bottom 26b and the second main surface 22. One side surface 26s of the first groove 26 can reflect the visible light in the first optical path OP1 toward the first optical path OP1 with less reduction without passing through the first light absorption member 51, and the other side surface 26s can reflect the visible light in the second optical path OP2 toward the second optical path OP2 with less reduction without passing through the first light absorption member 51. As a result, even when the first light absorption member 51 is arranged in the first groove 26, it is possible to suppress a decrease in the brightness of the first light-emitting portion 41 that emits light through the first LED 31, and it is possible to suppress a decrease in the brightness of the second light-emitting portion 42 that emits light through the second LED 32.

[0182] (8-3)

[0183] In the above-described display device 10, there is a case where even if the depth of the first groove 26 of the light guide member 20 is smaller than the distance between the first bottom 26b and the second main surface 22, it is possible to make the light leakage L 5% or less. For example, when the thickness of the above-described light guide member 20 is 1.5 mm, the width W of the first groove Gr1 is 3.0 mm, the plate thickness of the groove portion (the distance d from the bottom of the first groove Gr1 to the second main surface 22 of the light guide member 20) is 1.0 mm (0.5 mm is cut from the first main surface 21 of the light guide member 20), the first light absorption member AB1 is black, the absorption rate of visible light is 90%, and the reflection rate of visible light is 10%, it is possible to make the light leakage L 5% or less. In such a display device 10, although the light guide member 20 is, for example, as thin as 1.5 mm, compared with the case where, for example, the first groove 26 is cut by 0.75 mm or more, it is difficult to break in the portion of the first groove 26.

[0184] (8-4)

[0185] In the above-described display device 10, a second groove 27 and a third groove 28 are formed in the first main surface 21 of the light guide member 20. The second light absorption member 52 and the third light absorption member 53 are formed on the second bottom 27b of the second groove 27 and the third bottom 28b of the third groove 28. Alternatively, the second light absorption layer 72 and the third light absorption layer 73 as the light absorption members are arranged in the second groove facing portion PA2 and the third groove facing portion PA3 of the second main surface 22. Further, it is configured such that the first groove 26 and the second groove 27 are arranged so as to sandwich the first region AR1, and the first groove 26 and the third groove 28 are arranged so as to sandwich the second region AR2.

[0186] Such a display device 10 can reduce the visible light that bypasses from the second groove 27 side and enters the first region AR1 through the second groove 27 and the second light absorption member 52 or the second light absorption layer 72. In addition, the visible light that bypasses from the third groove 28 side and enters the second region AR2 can be reduced through the third groove 28 and the third light absorption member 53 or the third light absorption layer 73. As a result, it is possible to suppress a decrease in the contrast between light and dark of the first light-emitting portion 41 when the first LED 31 (first light-emitting element) emits light and when it does not emit light through the second groove 27 and the second light absorption member 52 or the second light absorption layer 72. Similarly, it is possible to suppress a decrease in the contrast between light and dark of the second light-emitting portion 42 when the second LED 32 (second light-emitting element) emits light and when it does not emit light through the third groove 28 and the third light absorption member 53 or the third light absorption layer 73.

[0187] (8-5)

[0188] In the above display device 10, at least a part of the first LED 31 (first light-emitting element) is disposed in the concave portion 23 of the light guide member 20 (see Figure 22 and Figure 23 ) in such a manner as to be located between the first main surface 21 and the second main surface 22 of the light guide member 20. Similarly, at least a part of the second LED 32 (second light-emitting element) is disposed in the concave portion 23. In the display device 10 configured in this way, the optical path from the first LED 31 toward the second region AR2 and the optical path from the second LED 32 toward the first region AR1 are blocked by the first groove 26. Since at least a part of the first light-emitting element and the second light-emitting element can be disposed in the concave portion of the light guide member, the thickness of the light guide member can be made thinner, and the distance between the first light-emitting element and the first light-emitting portion and the distance between the second light-emitting element and the second light-emitting portion can be shortened. As a result, the visible light leaking from the optical path of the first light-emitting element to the optical path of the second light-emitting element and the visible light leaking from the optical path of the second light-emitting element to the optical path of the first light-emitting element can be reduced.

[0189] (8-6)

[0190] The above display device 10 has a wiring pattern 62 to which a first LED 31 as a first light-emitting element, a second LED 32 as a second light-emitting element, and other third LEDs 33 are electrically connected. The wiring pattern 62 is formed on the circuit film 60, and the circuit film 60 is disposed on the first main surface 21 of the light guide member 20 and integrally formed with the light guide member 20. Such a display device 10 can easily reduce the thickness of the display device 10 in the direction from the first main surface 21 toward the second main surface 22 ( Figure 4 Z direction).

[0191] (8-7)

[0192] The above display device 10 can be configured such that the decorative layer 40 has a metal layer 80 or a low refractive index layer at a portion facing the first region AR1 and the second region AR2. In the display device 10 configured in this way, the diffusion of visible light in the first region AR1 and the second region AR2 can be suppressed, thereby suppressing the decrease in the brightness of the first light-emitting portion 41 and the second light-emitting portion 42.

[0193] (8-8) The manufacturing method of the above display device 10 can be configured to include a groove forming step in which the first main surface 21 of the light guide member 20 is cut to form a first groove 26 between the first LED 31 as the first light-emitting element and the second LED 32 as the second light-emitting element. In the manufacturing method of the display device 10 configured in this way, since the first groove 26 is formed by cutting after the molding of the light guide member 20, it is possible to provide a display device 10 that prevents the resin sink marks generated when forming the groove during molding and has less deformation of the decorative layer 40.

[0194] (8-9)

[0195] It is also possible to perform the molding step and the element setting step by insert molding the circuit film 60 and in-mold molding the decorative layer 40 after electrically connecting the first LED 31 and the second LED 32 to the circuit film 60. In the manufacturing method of the display device configured in this way, the first LED 31 and the second LED 32 can be easily set in the light guide member 20 by insert molding the first LED 31 and the second LED 32 into the light guide member 20. Especially in the case of performing insert molding and in-mold molding simultaneously, the molding time in the molding step can be shortened.

[0196] (8-10)

[0197] In the above display device 10, the light guide member 20 can be configured as a plate-like member with a thickness of 2.5 mm or less, the visible light absorption rate of the first light absorption member 51 is 70% or more, and the width W of the first groove 26 and the distance d between the first groove bottom and the second main surface satisfy 5.00≥(1.46d + 3.25)W 0.474d-1.43 such a relational expression. In the display device 10 configured in this way, even if the light guide member 20 is a thin plate-like member with a thickness of 2.5 mm, it is easy to suppress the leakage of visible light to the adjacent second optical path OP2 to 5% or less.

[0198] The first embodiment and the second embodiment of the present invention have been described above, but the present invention is not limited to the above embodiments, and various changes can be made without departing from the gist of the invention. In particular, the multiple embodiments and modification examples described in this specification can be arbitrarily combined as needed.

Claims

1. A display device, characterized in that, Comprising: A light guide member having a first main surface and a second main surface facing the first main surface, a first groove being formed in the first main surface, and the light guide member being made of a resin that transmits visible light; A first light-emitting element disposed on the first main surface of the light guide member and configured to irradiate visible light into the light guide member; A second light-emitting element disposed on the first main surface or the second main surface of the light guide member and configured to irradiate visible light into the light guide member; A decorative layer integrally formed with the light guide member and provided on at least one of the first main surface and the second main surface of the light guide member, and having a first light-emitting portion where visible light irradiated from the first light-emitting element radiates from the light guide member to the outside and a second light-emitting portion where visible light irradiated from the second light-emitting element radiates from the light guide member to the outside; and A light absorption member, which is a rod-shaped member configured to be in contact with the first groove bottom of the first groove and not in contact with the side surface of the first groove, and the visible light absorption rate of the light absorption member is greater than that of the light guide member, The light guide member has a first region in contact with one side surface of the first groove and a second region in contact with the other side surface of the first groove, The first light-emitting element and the first light-emitting portion are disposed in the first region, and the second light-emitting element and the second light-emitting portion are disposed in the second region, The first groove is disposed at a position that blocks the optical path from the first light-emitting element to the second region and blocks the optical path from the second light-emitting element to the first region.

2. The display device according to claim 1, wherein The depth of the first groove of the light guide member is smaller than the distance between the first groove bottom and the second main surface.

3. The display device according to claim 1 or 2, wherein The light guide member further forms a second groove and a third groove on the first main surface except for the first groove, The light absorption member is disposed on the second groove bottom of the second groove and the third groove bottom of the third groove, or is disposed on the second groove facing portion and the third groove facing portion of the second main surface facing the second groove bottom and the third groove bottom, The first groove and the second groove are disposed so as to sandwich the first region, and the first groove and the third groove are disposed so as to sandwich the second region.

4. The display device according to claim 1 or 2, wherein A circuit film is provided, which has a wiring pattern for electrically connecting the first light-emitting element and the second light-emitting element, and is disposed on the first main surface of the light guide member and integrally formed with the light guide member.

5. The display device according to claim 1 or 2, wherein The decorative layer has a metal layer or a low refractive index layer in a portion facing the first region and the second region.

6. A manufacturing method of a display device, characterized in that, Comprising: A forming step, in which a circuit film is integrally formed on a first main surface of a resin light guide member that transmits visible light, and a decorative layer is integrally formed on a second main surface of the light guide member; An element setting step, in which a first light-emitting element and a second light-emitting element are set in such a manner that the first light-emitting element and the second light-emitting element are electrically connected to the circuit film and the first light-emitting element and the second light-emitting element can irradiate visible light into the light guide member; A groove forming step, in which the first main surface of the light guide member is cut to form a first groove between the first light-emitting element and the second light-emitting element; And A light absorption member setting step, in which the light absorption member is a rod-shaped member arranged in such a manner that it is in contact with a first groove bottom of the first groove and not in contact with a side surface of the first groove, and the light absorption member is set in such a manner that the visible light absorption rate of the light absorption member is greater than that of the light guide member; The decorative layer has a first light-emitting portion where visible light irradiated from the first light-emitting element radiates from the light guide member to the outside and a second light-emitting portion where visible light irradiated from the second light-emitting element radiates from the light guide member to the outside; The light guide member has a first region that is in contact with one side surface of the first groove and where the first light-emitting element and the first light-emitting portion are arranged, and a second region that is in contact with the other side surface of the first groove and where the second light-emitting element and the second light-emitting portion are arranged; The first groove is arranged at a position that blocks the optical path from the first light-emitting element to the second region and blocks the optical path from the second light-emitting element to the first region.

7. The method for manufacturing a display device according to claim 6, characterized in that: The forming step and the element setting step are implemented in the following manner: after electrically connecting the first light-emitting element and the second light-emitting element to the circuit film, the decorative layer is formed in the mold by insert molding the circuit film.

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