Display device

Abstract

To provide a display device whose casing can be narrowed.SOLUTION: A display device includes a first substrate including a first surface, a second surface on the opposite side of the first surface, and a first side surface connecting the first surface and the second surface, a second substrate including a second side surface and opposed to the first surface, a light source provided along the second side surface of the second substrate, a wiring substrate opposed to the second surface of the first substrate, a first adhesive layer attaching the second surface and the wiring substrate to each other, and a flexible wiring substrate electrically connecting the first substrate and the wiring substrate. The first substrate includes an extension part including the first side surface and extending over the second side surface of the second substrate. The flexible wiring substrate is mounted on the extension part.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present embodiment relates to a display device. [Background technology]

[0002] In recent years, display devices equipped with a display panel having a polymer dispersed liquid crystal layer (PDLC; Polymer Dispersed Liquid Crystal) have been proposed (for example, Patent Document 1). The polymer dispersed liquid crystal layer can be switched between a scattering state in which light is scattered and a transparent state in which light is transmitted. By switching the display panel to the scattering state, the display device is able to display an image. On the other hand, by switching the display panel to the transparent state, the user is able to see the background through the display panel. Conventionally, there has been a demand for display devices to have a reduced frame portion located outside the display area, that is, a so-called narrow frame. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-33043 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a display device that can have a narrow frame. [Means for solving the problem]

[0005] In one embodiment, the display device includes a first surface, a second surface opposite to the first surface, and a first a first substrate having a first side surface connecting the first surface and the second surface; a second substrate facing the second side surface of the first substrate; a light source provided along the second side surface of the second substrate; a wiring board facing the second surface of the first substrate, and a first adhesive for bonding the second surface and the wiring board; and a flexible wiring board that electrically connects the first substrate and the wiring board. The first substrate includes the first side surface and extends beyond the second side surface of the second substrate. The flexible wiring board has an extending portion, and the flexible wiring board is mounted on the extending portion. The flexible wiring board has a first end connected to the extending portion, a second end connected to the wiring board, a first bent portion and a second bent portion between the first end and the second end, a thick portion between the first bent portion and the second bent portion, and a first portion between the second bent portion and the second end. The flexible wiring board is bent toward the second surface of the first substrate by the first bent portion. The thick portion has an overlapping portion that overlaps with the first portion in the thickness direction of the first substrate. In the overlapping portion, the thick portion is thicker than the first portion. A display device in another embodiment includes a first substrate having a first surface, a second surface opposite to the first surface, and a first side surface connecting the first surface and the second surface, a second substrate having a second side surface and facing the first surface, a light source provided along the second side surface of the second substrate, a wiring substrate facing the second surface of the first substrate, and a first adhesive layer bonding the second surface and the wiring substrate, A second adhesive layer; and a flexible wiring board electrically connecting the first substrate and the wiring board, the first substrate including the first side surface and having an extension portion extending beyond the second side surface of the second substrate, the flexible wiring board being mounted on the extension portion. The flexible wiring board has a first end portion connected to the extension portion, a second end portion connected to the wiring substrate, a first bent portion and a second bent portion between the first end portion and the second end portion, a first portion between the second bent portion and the second end portion, and a third portion between the first bent portion and the second bent portion. The first portion has an overlapping portion overlapping the third portion, and the second adhesive layer bonds the third portion and the first portion at the overlapping portion. The second end portion is connected at a position closer to the side surface of the wiring board facing the first bent portion than the second bent portion. In the overlapping portion, the third portion is thicker than the first portion. [Brief description of the drawings]

[0006] [Figure 1]FIG. 1 is a plan view showing a configuration example of a display device according to a first embodiment. [Diagram 2] FIG. 2 is a bottom view showing an example of the configuration of the display device in the first embodiment. [Diagram 3] FIG. 3 is a cross-sectional view showing an example of a configuration of the display panel shown in FIGS. [Figure 4] FIG. 4 is a perspective view showing a configuration example of the light emitting module shown in FIG. [Diagram 5] FIG. 5 is a cross-sectional view showing a configuration example of the display device according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a comparative example of the display device shown in FIG. [Figure 7] FIG. 7 is a cross-sectional view showing a configuration example of a display device according to the second embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing a configuration example of a display device according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The disclosure is merely an example, and those who are skilled in the art can easily come up with appropriate modifications that maintain the gist of the invention, and naturally, these modifications are included in the scope of the present invention. In addition, the drawings may be more schematic than the actual embodiment in order to make the explanation clearer, but they are merely an example and do not limit the interpretation of the present invention.

[0008] In each figure, the reference numerals may be omitted for the same or similar elements arranged consecutively. In addition, in this specification and each figure, the same reference numerals may be used for components that perform the same or similar functions as those described above with respect to the previous figures, and duplicate detailed descriptions may be omitted.

[0009] In each embodiment, a first direction X, a second direction Y, and a third direction Z are defined as shown in each drawing. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other, but may intersect at an angle other than 90°. In each embodiment, the third direction Z is defined as up or upward, and the direction opposite to the third direction Z is defined as down or downward.

[0010] In the case of "a second member above a first member" and "a second member below a first member," the second member may be in contact with the first member or may be located away from the first member. Hereinafter, viewing the XY plane defined by the first direction X and the second direction Y will be referred to as planar view.

[0011] In each embodiment, a light-transmitting liquid crystal display device that uses a polymer-dispersed liquid crystal and allows the background to be viewed is disclosed as an example of a display device. Note that each embodiment does not prevent the application of each technical idea disclosed in each embodiment to other types of display devices.

[0012] [First embodiment] Fig. 1 is a plan view showing an example of the configuration of the display device DSP1 in the first embodiment, Fig. 2 is a bottom view showing an example of the configuration of the display device DSP1 in the first embodiment. 1 and 2, the display device DSP1 includes a display panel PNL having a polymer dispersed liquid crystal layer (hereinafter simply referred to as a liquid crystal layer LC), a flexible wiring board 1, an IC chip 2, a wiring board 3, and a light emitting module 100. The display device DSP1 further includes a first cover member 30 and a second cover member 40, which will be described later.

[0013] The display panel PNL has a first substrate SUB1, a second substrate SUB2, a liquid crystal layer LC, and a seal SE. The first substrate SUB1 and the second substrate SUB2 are flat plates parallel to the XY plane. The first substrate SUB1 and the second substrate SUB2 overlap each other in a planar view. The first substrate SUB1 and the second substrate SUB2 are bonded together by the seal SE. The liquid crystal layer LC is disposed between the first substrate SUB1 and the second substrate SUB2, and is sealed by the seal SE.

[0014] As shown enlarged and schematic in FIG. 1, the liquid crystal layer LC includes a polymer 31 and liquid crystal molecules 32. In one example, the polymer 31 is a liquid crystal polymer. The polymer 31 is formed in stripes extending along a first direction X and aligned in a second direction Y. The liquid crystal molecules 32 are dispersed in the gaps between the polymer 31 and oriented such that their major axes are aligned along the first direction X. Each of the polymer 31 and the liquid crystal molecules 32 has optical anisotropy or refractive index anisotropy. The responsiveness of the polymer 31 to an electric field is lower than the responsiveness of the liquid crystal molecules 32 to an electric field.

[0015] In one example, the orientation direction of the polymer 31 hardly changes regardless of the presence or absence of an electric field. On the other hand, the orientation direction of the liquid crystal molecules 32 changes in response to an electric field when a high voltage equal to or higher than a threshold value is applied to the liquid crystal layer LC. When no voltage is applied to the liquid crystal layer LC, the optical axes of the polymer 31 and the liquid crystal molecules 32 are parallel to each other, and light incident on the liquid crystal layer LC is transmitted through the liquid crystal layer LC without being scattered therethrough (transmission state). When a voltage is applied to the liquid crystal layer LC, the optical axes of the polymer 31 and the liquid crystal molecules 32 cross each other, and light incident on the liquid crystal layer LC is scattered therethrough (scattering state).

[0016] The display panel PNL has a display area DA for displaying an image and a peripheral area PA surrounding the display area DA in a frame shape. The seal SE is located in the peripheral area PA. The display area DA includes pixels PX arranged in a matrix in a first direction X and a second direction Y.

[0017] As shown in an enlarged view in Fig. 1, each pixel PX includes a switching element SW, a pixel electrode PE, a common electrode CE, a liquid crystal layer LC, etc. The switching element SW is formed of, for example, a thin film transistor (TFT) and is electrically connected to a scanning line G and a signal line S. The scanning line G is electrically connected to the switching element SW in each of the pixels PX aligned in the first direction X. The signal line S is electrically connected to the switching element SW in each of the pixels PX aligned in the second direction Y.

[0018] The pixel electrode PE is electrically connected to the switching element SW. The common electrode CE is provided in common to the plurality of pixel electrodes PE. The liquid crystal layer LC (particularly, the liquid crystal molecules 32) is driven by an electric field generated between the pixel electrode PE and the common electrode CE. The capacitance CS is formed, for example, between an electrode having the same potential as the common electrode CE and an electrode having the same potential as the pixel electrode PE.

[0019] 3, the scanning lines G, signal lines S, switching elements SW, and pixel electrodes PE are provided on a first substrate SUB1, and the common electrode CE is provided on a second substrate SUB2. In the first substrate SUB1, the scanning lines G and signal lines S are electrically connected to a flexible wiring substrate 1 or an IC chip 2.

[0020] The first substrate SUB1 has a pair of side surfaces E11, E12 extending along the first direction X, and a pair of side surfaces E13, E14 extending along the second direction Y. In the example shown in Figures 1 and 2, the side surfaces E11, E12 are side surfaces formed along the long sides, and the side surfaces E13, E14 are side surfaces formed along the short sides.

[0021] The second substrate SUB2 has a pair of side surfaces E21, E22 extending along the first direction X, and a pair of side surfaces E23, E24 extending along the second direction Y. In the example shown in Figures 1 and 2, the side surfaces E21, E22 are side surfaces formed along the long sides, and the side surfaces E23, E24 are side surfaces formed along the short sides.

[0022] In the examples shown in FIG. 1 and FIG. 2, the side surfaces E12 and E22, the side surfaces E13 and E23, and the side surfaces E14 and E24 overlap each other in a plan view, but they do not have to overlap.

[0023] The first substrate SUB1 has an extension portion Ex1 that extends beyond the side surface E21 of the second substrate SUB2. From another perspective, the extension portion Ex1 does not overlap with the second substrate SUB2. The extension portion Ex1 includes the side surface E11. The side surface E21 is located between the side surface E11 and the display area DA in a plan view. Note that the shapes of the first substrate SUB1 and the second substrate SUB2 are not limited to rectangular shapes.

[0024] The flexible wiring board 1 and the IC chip 2 are mounted on the extending portion Ex1. The flexible wiring board 1 is, for example, a flexible printed circuit board, and is bent toward the wiring board 3 in the example shown in Fig. 1 and Fig. 2. The IC chip 2 has, for example, a built-in display driver that outputs signals necessary for image display. The IC chip 2 may be mounted on the flexible wiring board 1.

[0025] 1 and 2, the display device DSP1 includes a plurality of (for example, four) flexible wiring boards 1, but may include a single flexible wiring board 1. In addition, the display device DSP1 includes a plurality of (for example, four) IC chips 2, but may include a single IC chip 2.

[0026] The wiring board 3 is, for example, a printed circuit board. The wiring board 3 has a higher rigidity than, for example, the flexible wiring board 1. From another perspective, the thickness of the wiring board 3 is greater than, for example, the thickness of the flexible wiring board 1. That is, the wiring board 3 is harder to bend than the flexible wiring board 1. As shown in FIG. 2, the wiring board 3 has a connector 4. The flexible wiring board 1 is connected to the wiring board 3 via the connector 4. From another perspective, the flexible wiring board 1 electrically connects the first substrate SUB1 to the wiring board 3.

[0027] Furthermore, the wiring board 3 is connected to a control unit (not shown) via a connector 5. Various signals and power supply voltages output from the control unit are output to the display panel PNL via the wiring board 3 and the flexible wiring board 1. The wiring board 3 has a side surface E31 at a position protruding from the side surface E11 of the first substrate SUB1. The side surface E11 is located between the side surfaces E21 and E31 in a plan view.

[0028] The light emitting module 100 will be described in detail later, but the light emitting module 100 is provided along a side surface (or an end portion) of the display panel PNL. In the example shown in FIG. 1, the light emitting module 100 is provided on an extending portion Ex1. The light emitting module 100 has a wiring board 101. The wiring board 101 is electrically connected to the outside via a connector 6 for inputting various signals and power supply voltages. The wiring boards 3, 101 may have portions extending from the display panel PNL in the first direction X and in the direction opposite to the first direction X.

[0029] Fig. 3 is a cross-sectional view showing a configuration example of the display panel PNL shown in Fig. 1 and Fig. 2. The first substrate SUB1 has a transparent substrate 10, insulating films 11 and 12, a capacitance electrode 13, a switching element SW, a pixel electrode PE, and an alignment film AL1. The transparent substrate 10 has a main surface 10A (second surface) and a main surface 10B (first surface) opposite to the main surface 10A.

[0030] The switching element SW is provided on the main surface 10B side. The insulating film 11 is provided on the main surface 10B and covers the switching element SW. The scanning line G and the signal line S shown in FIG. 1 are provided between the transparent substrate 10 and the insulating film 11, but are not shown here. The capacitance electrode 13 is provided between the insulating film 11 and the insulating film 12.

[0031] The pixel electrode PE is provided for each pixel PX between the insulating film 12 and the alignment film AL1. That is, the capacitance electrode 13 is provided between the transparent substrate 10 and the pixel electrode PE. The pixel electrode PE is electrically connected to the switching element SW through an opening OP of the capacitance electrode 13. The pixel electrode PE overlaps with the capacitance electrode 13 with the insulating film 12 sandwiched therebetween to form a capacitance CS of the pixel PX. The alignment film AL1 covers the pixel electrode PE.

[0032] The second substrate SUB2 faces the first substrate SUB1. The second substrate SUB2 has a transparent substrate 20, a common electrode CE, and an alignment film AL2. The transparent substrate 20 has a main surface 20A and a main surface 20B opposite to the main surface 20A. The main surface 20A of the transparent substrate 20 faces the main surface 10B of the transparent substrate 10.

[0033] The common electrode CE is provided on the main surface 20A. The alignment film AL2 covers the common electrode CE. The liquid crystal layer LC is located between the main surface 10B and the main surface 20A, and is in contact with the alignment films AL1 and AL2. Note that, in the second substrate SUB2, light-shielding layers may be provided directly above the switching elements SW, the scanning lines G, and the signal lines S. Also, a transparent insulating film may be provided between the transparent substrate 20 and the common electrode CE, or between the common electrode CE and the alignment film AL2.

[0034] The common electrode CE is disposed across the multiple pixels PX and faces the multiple pixel electrodes PE in the third direction Z. The common electrode CE has the same potential as the capacitance electrode 13. The liquid crystal layer LC is located between the pixel electrodes PE and the common electrode CE.

[0035] The transparent substrates 10 and 20 are, for example, glass substrates, but may be insulating substrates such as plastic substrates. The insulating film 11 includes a transparent inorganic insulating film such as silicon oxide, silicon nitride, silicon oxynitride, and a transparent organic insulating film such as acrylic resin. The insulating film 12 is a transparent inorganic insulating film such as silicon nitride. The capacitance electrode 13, the pixel electrode PE, and the common electrode CE are transparent electrodes formed of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0036] Fig. 4 is a perspective view showing an example of the configuration of the light emitting module 100 shown in Fig. 1. The light emitting module 100 includes a wiring board 101, an adhesive layer 102, a plurality of light sources 110, and a light guide body (for example, a prism lens) 120.

[0037] The light sources 110 face the light guide 120 in the second direction Y. The light sources 110 are arranged at intervals along the first direction X, and are electrically connected to the wiring board 101.

[0038] The light source 110 is a continuous arrangement of red, green, and blue LEDs. The light source 110 is not limited to an arrangement in which three different color LEDs are continuously arranged, and may be, for example, an arrangement in which only white light sources that emit white light are continuously arranged.

[0039] The light guide 120 is made of, for example, resin, and is formed into a transparent rod shape extending along the first direction X. The light guide 120 has, for example, a plurality of curved surfaces corresponding to each light source 110, and controls the width in the first direction X of the light emitted from the light source 110. The light guide 120 is bonded to the wiring board 101 by an adhesive layer 102. The light guide 120 may be composed of a plurality of light guides. Note that the number of light sources 110 and the number of light guides 120 included in the light emitting module 100 are not limited to the example shown in the figure.

[0040] FIG. 5 is a cross-sectional view showing a configuration example of the display device DSP1 in the first embodiment. As described above, the display device DSP1 includes the display panel PNL, the flexible wiring board 1, the IC chip 2, the wiring board 3, and the light emitting module 100. Note that the display panel PNL is illustrated in a simplified manner, with only the main parts being shown.

[0041] The display device DSP1 further includes a first cover member 30, a second cover member 40, an adhesive layer AD1 that bonds the second substrate SUB2 and the first cover member 30, an adhesive layer AD2 that bonds the first substrate SUB1 and the second cover member 40, and an adhesive layer AD3 (first adhesive layer) that bonds the first substrate SUB1 and the wiring substrate 3. In the example shown in Fig. 5, the first cover member 30 and the second cover member 40 overlap the display area DA in the third direction Z, but do not overlap the extension portion Ex1. Also, the wiring substrate 3 overlaps the extension portion Ex1 in the third direction Z, but does not overlap the display area DA.

[0042] As described with reference to FIG. 1, in the first substrate SUB1, the transparent substrate 10 has a side surface E11 (first side surface). The side surface E11 connects the main surface 10A and the main surface 10B. In the second substrate SUB2, the transparent substrate 20 has a side surface E21 (second side surface). The side surface E21 connects the main surface 20A and the main surface 20B. The side surface E11 protrudes beyond the side surface E21 of the transparent substrate 20 in the direction opposite to the second direction Y. The side surfaces E11 and E21 are surfaces approximately parallel to the XZ plane defined by the first direction X and the third direction Z.

[0043] The first cover member 30 has a main surface 30A, a main surface 30B opposite to the main surface 30A, and a side surface 30C connecting the main surface 30A and the main surface 30B. The main surfaces 30A and 30B are surfaces that are approximately parallel to the XY plane. The main surface 30A faces the main surface 20B of the transparent substrate 20. The side surface 30C is a surface that is approximately parallel to the XZ plane. The side surface 30C is located on the light emitting module 100 side in the second direction Y. In the example shown in FIG. 5, the side surface 30C is located directly above the side surface E21, but may be shifted in the second direction Y.

[0044] The second cover member 40 has a main surface 40A, a main surface 40B opposite to the main surface 40A, and a side surface 40C connecting the main surface 40A and the main surface 40B. The main surfaces 40A and 40B are surfaces that are approximately parallel to the XY plane. The main surface 40B faces the main surface 10A of the transparent substrate 10. The side surface 40C is a surface that is approximately parallel to the XZ plane. The side surface 40C is located on the light emitting module 100 side in the second direction Y. The side surface 40C faces the wiring board 3.

[0045] The side 40C is located closer to the display area DA than the side 30C in the second direction Y. In the example shown in FIG. 5, the side 40C is not located directly below the side 30C in the third direction Z, but overlaps with the peripheral area PA1 between the side E21 (side 30C) and the display area DA. From another perspective, the side 40C is located between the side 30C and the display area DA in the second direction Y. In the example shown in FIG. 5, the side 40C is a distance L1 away from the side 30C in the second direction Y. Meanwhile, in the example shown in FIG. 5, the side opposite the side 40C in the second cover member 40 is located directly below the side opposite the side 30C.

[0046] The adhesive layer AD1 bonds the main surface 20B of the transparent substrate 20 and the main surface 30A of the first cover member 30. The adhesive layer AD1 has an end portion AD1a on the side surface 30C side in the second direction Y. The adhesive layer AD1 is not formed up to just below the side surface 30C, but may be formed up to just below the side surface 30C.

[0047] The adhesive layer AD2 bonds the main surface 10A of the transparent substrate 10 and the main surface 40B of the second cover member 40. The adhesive layer AD2 has an end portion AD2a on the side surface 40C side in the second direction Y. The adhesive layer AD2 is not formed up to directly above the side surface 40C, but may be formed up to directly above the side surface 40C.

[0048] The adhesive layers AD1 and AD2 overlap the display area DA in the third direction Z. From another perspective, the liquid crystal layer LC in the display area DA is located between the adhesive layers AD1 and AD2 in the third direction Z. The adhesive layers AD1 and AD2 can, for example, block most of the ultraviolet rays. Here, blocking includes reflecting and absorbing the ultraviolet rays. By forming the adhesive layers AD1 and AD2 to cover the display area DA, the effect of the ultraviolet rays contained in external light on the liquid crystal layer LC can be suppressed.

[0049] The ends AD1a and AD2a overlap with the peripheral area PA1 in the third direction Z. The end AD2a is located closer to the display area DA than the end AD1a. In the example shown in FIG. 5, the end AD2a is located between the end AD1a and the display area DA in the second direction Y, and between the side surface 40C and the display area DA. The adhesive layers AD1 and AD2 are formed of, for example, Optical Clear Adhesive (OCA).

[0050] 5, the transparent substrate 10, the transparent substrate 20, the first cover member 30, and the second cover member 40 each have approximately the same thickness along the third direction Z. The first cover member 30 and the second cover member 40 are, for example, glass substrates, but may also be insulating substrates such as plastic substrates.

[0051] The light emitting module 100 overlaps with the extension portion Ex1 in the third direction Z. The light source 110 and the light guide 120 are provided between the extension portion Ex1 of the transparent substrate 10 and the wiring substrate 101 in the third direction Z. In the example shown in Fig. 5, the light source 110 and the light guide 120 are provided along the side surface E21. The light guide 120 is provided between the light source 110 and the side surface E21 and between the light source 110 and the side surface 30C in the second direction Y.

[0052] The light guide 120 is adhered to the wiring substrate 101 by an adhesive layer 102, and is adhered to the extension portion Ex1 by an adhesive layer 103. The adhesive layers 102 and 103 are formed of, for example, double-sided tape. The adhesive layers 102 and 103 are formed of, for example, a reflective layer and adhesive layers formed on both sides of the reflective layer.

[0053] Next, the light emitted from the light source 110 will be described. The light source 110 emits light toward at least one of the side surface 30C and the side surface E21. In the example shown in Fig. 5, the light source 110 emits light toward the side surface 30C and the side surface E21. The light emitted from the light source 110 is appropriately diffused in the light guide 120, enters the transparent substrate 20 from the side surface E21, and enters the first cover member 30 from the side surface 30C.

[0054] The light incident on the transparent substrate 20 and the first cover member 30 propagates inside the display panel PNL while being repeatedly reflected. The light incident on the liquid crystal layer LC to which no voltage is applied passes through the liquid crystal layer LC with almost no scattering.

[0055] Moreover, light incident on the liquid crystal layer LC to which a voltage is applied is scattered by the liquid crystal layer LC. In the display device DSP1, an image can be observed from the main surface 30B side as well as from the main surface 40A side. Moreover, whether the display device DSP1 is observed from the main surface 30B side or from the main surface 40A side, the background of the display device DSP1 can be observed through the display device DSP1.

[0056] The wiring board 3 has a main surface 3B (third surface) facing the main surface 10A, a main surface 3A (fourth surface) opposite the main surface 3B, and a pair of side surfaces E31 and E32. A connector 4 to which the flexible wiring board 1 is connected is provided on the main surface 3A. The main surfaces 3A and 3B are surfaces that are approximately parallel to the XY plane. The pair of side surfaces E31 and E32 are surfaces that are approximately parallel to the XZ plane. The pair of side surfaces E31 and E32 connect the main surface 3A and the main surface 3B.

[0057] 5, the connector 4 is located on the side surface E32 side from the center in the second direction Y of the main surface 3A of the wiring board 3. The connector 4 overlaps with the light guide 120 in, for example, the third direction Z. However, the position of the connector 4 on the main surface 3A is not limited to the example shown in the figure.

[0058] The wiring board 3 protrudes from the side surface E11 of the transparent substrate 10. From another perspective, the side surface E31 protrudes from the side surface E11 of the transparent substrate 10 in the direction opposite to the second direction Y. The side surface E32 is located opposite the side surface E31 and faces the side surface 40C of the second cover member 40. The wiring board 3 is aligned with the second cover member 40 in the second direction Y and is located to the left of the second cover member 40 in the example shown in FIG.

[0059] The adhesive layer AD3 bonds the main surface 10A of the transparent substrate 10 and the main surface 3B of the wiring board 3. The adhesive layer AD3 is not formed up to just above the side surface E32 of the wiring board 3, but may be formed up to just above the side surface E32. The adhesive layer AD3 is formed of, for example, double-sided tape.

[0060] The side surface E32 of the wiring board 3 overlaps with the peripheral area PA1 in the third direction Z. From another perspective, the side surface E32 is located between the side surface 40C and the side surface 30C in the second direction Y. In the example shown in FIG. 5, the wiring board 3 overlaps with the first cover member 30 and the transparent substrate 20 in the third direction Z. The adhesive layer AD3 does not overlap with the peripheral area PA1 in the third direction Z, but may be formed up to a position where it overlaps with the peripheral area PA1.

[0061] The flexible wiring board 1 has a first end 1a and a second end 1b opposite to the first end 1a. The first end 1a is connected to the extension portion Ex1 of the first substrate SUB1, and the second end 1b is connected to a connector 4 provided on the wiring substrate 3.

[0062] Flexible wiring board 1 further has, from the first end 1a side, a first bent portion 1A, a thick portion 1B, a second bent portion 1C, a first portion 1D, a third bent portion 1E, and a second portion 1F between first end 1a and second end 1b. Flexible wiring board 1 is bent toward main surface 10A of transparent substrate 10 by first bent portion 1A so as to straddle wiring board 3. Extension portion Ex1 and wiring board 3 are located between flexible wiring board 1 in third direction Z.

[0063] The thick portion 1B is located between the first bent portion 1A and the second end portion 1b. The thick portion 1B overlaps with the wiring board 3 in the thickness direction (third direction Z) of the transparent substrate 10. The thickness D2 of the thick portion 1B is thicker than the thickness D1 of the portions other than the thick portion 1B (the first bent portion 1A, the second bent portion 1C, the first portion 1D, the third bent portion 1E, and the second portion 1F) (D2>D1), for example. From another viewpoint, the thick portion 1B has a higher rigidity than the portions other than the thick portion 1B, and is difficult to bend.

[0064] In the thick portion 1B, wiring is formed on both sides of a base material formed of, for example, polyimide. From another viewpoint, in the thick portion 1B, for example, more layers are formed on the base material than in the portion other than the thick portion 1B. In addition, the width in the first direction X of the thick portion 1B is, for example, approximately equal to the width in the first direction X of the first bent portion 1A, and is smaller than the width in the first direction X of the second bent portion 1C, the first portion 1D, the third bent portion 1E, and the second portion 1F.

[0065] The second bent portion 1C is located between the thick portion 1B and the second end 1b, and the first portion 1D is located between the second bent portion 1C and the second end 1b. The third bent portion 1E is located between the first portion 1D and the second end 1b, and the second portion 1F is located between the third bent portion 1E and the second end 1b. The second bent portion 1C is located closer to the display area DA than the first bent portion 1A in the second direction Y. The third bent portion 1E is located between the first bent portion 1A and the second bent portion 1C in the second direction Y.

[0066] Flexible wiring board 1 is bent at second bent portion 1C, and first portion 1D is located between thick portion 1B and wiring board 3 in third direction Z. Furthermore, flexible wiring board 1 is bent at third bent portion 1E, and second portion 1F is located between first portion 1D and wiring board 3 in third direction Z.

[0067] In the example of Fig. 5, the width in the second direction Y of the thick portion 1B is larger than the widths in the second direction Y of the first portion 1D and the second portion 1F. Also, in the example of Fig. 5, the widths in the second direction Y of the first portion 1D and the second portion 1F are approximately equal, but the width in the second direction Y of the first portion 1D may be larger or smaller than the width in the second direction Y of the second portion 1F.

[0068] Flexible wiring board 1 is bent into an S-shape in cross section in a YZ plane defined by second direction Y and third direction Z. By bending flexible wiring board 1 not only at first bent portion 1A but also at second bent portion 1C and third bent portion 1E, flexible wiring board 1 can be connected to connector 4 located on side surface E32 of wiring board 3, and the width of flexible wiring board 1 in second direction Y when connected can be reduced. In this case, most of thick portion 1B overlaps with wiring board 3 in the third direction Z.

[0069] The display device DSP1 further includes an adhesive layer 7A (second adhesive layer) that bonds the thick portion 1B and the first portion 1D, and an adhesive layer 7B (third adhesive layer) that bonds the first portion 1D and the second portion 1F. The adhesive layers 7A and 7B are formed of, for example, double-sided tape. Below the wiring board 3, the thick portion 1B, adhesive layer 7A, first portion 1D, adhesive layer 7B, and second portion 1F are arranged in this order along the third direction Z.

[0070] In the example shown in Figure 5, the widths in the second direction Y of the adhesive layers 7A and 7B are approximately equal, but the width in the second direction Y of the adhesive layer 7A may be wider than the width in the second direction Y of the adhesive layer 7B, or the width in the second direction Y of the adhesive layer 7A may be narrower than the width in the second direction Y of the adhesive layer 7B.

[0071] 5, the thicknesses in the third direction Z of the adhesive layers 7A and 7B are approximately equal, but the thickness in the third direction Z of the adhesive layer 7A may be thicker than the thickness in the third direction Z of the adhesive layer 7B, or the thickness in the third direction Z of the adhesive layer 7A may be thinner than the thickness in the third direction Z of the adhesive layer 7B. The adhesive layer 7A overlaps with the adhesive layer 7B in the third direction Z, but may be shifted in the second direction Y without overlapping with the adhesive layer 7B.

[0072] 5, thick portion 1B and first portion 1D do not overlap with connector 4 in the third direction Z, but thick portion 1B and first portion 1D may overlap with connector 4. In this case, second bent portion 1C may be located between connector 4 and side surface E32 of wiring board 3 in the second direction Y, or may overlap with connector 4 in the third direction Z.

[0073] The adhesive layers 7A and 7B suppress the spread of the flexible wiring board 1 in the third direction Z. In the example shown in Fig. 5, the adhesive layers 7A and 7B are provided, but only the adhesive layer 7A may be provided between the thick portion 1B and the first portion 1D, only the adhesive layer 7B may be provided between the first portion 1D and the second portion 1F, or each of the adhesive layers 7A and 7B may not be provided.

[0074] Fig. 6 is a cross-sectional view showing a comparative example of the display device DSP1 shown in Fig. 5. In the example shown in Fig. 6, the wiring board 3 does not overlap with the transparent substrate 10 in the third direction Z, but is aligned with the transparent substrate 10 in the second direction Y, and is located to the left of the transparent substrate 10 in the example shown in Fig. 6. The flexible wiring board 1 is not bent. The flexible wiring board 1 is mounted on the transparent substrate 10 at the same position as in the case shown in Fig. 5. The connector 4 is not shown in Fig. 6.

[0075] 6, a distance L20 from the display area DA to a side surface of the wiring board 3 opposite to the side surface facing side E11 of the transparent substrate 10 is longer than a distance L2 from the display area DA to the most protruding portion of the first bent portion 1A in the opposite direction to the second direction Y shown in Fig. 5 (L20>L2). The distances L2 and L20 correspond to the width in the second direction Y of the frame portion including the peripheral area PA1 and the extension portion Ex1.

[0076] In the case of the display device DSP1 shown in Fig. 6 as a comparative example, the frame portion including the display area DA, the peripheral area PA1, and the extension portion Ex1 is larger than that of the display device DSP1 shown in Fig. 5. By disposing the wiring board 3 on the main surface 10A side of the transparent substrate 10 with the adhesive layer AD3 and connecting the transparent substrate 10 and the wiring board 3 with the flexible wiring board 1, it is possible to reduce the width of the frame portion in the second direction Y.

[0077] As described above, the first embodiment can provide a display device DSP1 that can have a narrow frame. That is, the wiring board 3 is disposed on the main surface 10A side of the transparent substrate 10 by the adhesive layer AD3, and the flexible wiring board 1 is folded to connect the transparent substrate 10 and the wiring board 3, thereby making the frame smaller.

[0078] Furthermore, by bending the flexible wiring board 1 not only at the first bending portion 1A but also at the second bending portion 1C and the third bending portion 1E and connecting it to the connector 4 of the wiring board 3, the distance L2 can be reduced. Also, by positioning the connector 4 on the side surface E31 side from the center in the second direction Y of the main surface 3A of the wiring board 3, the distance L2 can be reduced. By reducing the frame portion in this manner, a narrow frame can be achieved in the display device DSP1. In addition, the first embodiment can provide the various effects described above.

[0079] In the first embodiment, the flexible wiring board 1 had two second bends 1C and a third bend 1E between the thick portion 1B and the second end 1b, but it may have three or more bends between the thick portion 1B and the second end 1b.

[0080] [Second embodiment] A second embodiment will be described. The same components as those in the first embodiment are given the same reference numerals, and the description will be omitted as appropriate. Fig. 7 is a cross-sectional view showing a configuration example of a display device DSP2 in the second embodiment. As shown in Fig. 7, the display device DSP2 includes a display panel PNL, a flexible wiring board 1, an IC chip 2, a wiring board 3, and a light-emitting module 100. Note that the display panel PNL is illustrated in a simplified form, with only the main parts being shown.

[0081] The display device DSP2 further includes a first cover member 30, a second cover member 40, an adhesive layer AD1 that bonds the second substrate SUB2 and the first cover member 30, an adhesive layer AD2 that bonds the first substrate SUB1 and the second cover member 40, and an adhesive layer AD3 that bonds the first substrate SUB1 and the wiring substrate 3. Between the first end 1a and the second end 1b, the flexible wiring substrate 1 has, from the first end 1a side, a first bent portion 1A, a thick portion 1B, a second bent portion 1C, a first portion 1D, a third bent portion 1E, and a second portion 1F.

[0082] The display device DSP2 further includes an adhesive layer 7A that bonds the thick portion 1B and the first portion 1D, an adhesive layer 7B that bonds the first portion 1D and the second portion 1F, and an adhesive layer 8 (fourth adhesive layer) that bonds the second portion 1F and the main surface 3A of the wiring board 3. The display device DSP2 in the second embodiment differs from the first embodiment in that it includes the adhesive layer 8. The adhesive layer 8 is formed of, for example, double-sided tape. The adhesive layer 8 may be formed of the same material as the adhesive layers 7A and 7B, or may be formed of a different material.

[0083] In the example shown in Figure 7, the width in the second direction Y of the adhesive layer 8 is approximately equal to the width in the second direction Y of the adhesive layers 7A and 7B, but the width in the second direction Y of the adhesive layer 8 may be wider than the width in the second direction Y of the adhesive layers 7A and 7B, or the width in the second direction Y of the adhesive layer 8 may be narrower than the width in the second direction Y of the adhesive layers 7A and 7B.

[0084] In the example shown in Figure 7, the thickness in the third direction Z of adhesive layer 8 is thinner than the thickness in the third direction Z of adhesive layers 7A, 7B, but the thickness in the third direction Z of adhesive layer 8 may be approximately equal to the thickness in the third direction Z of adhesive layers 7A, 7B, or the thickness in the third direction Z of adhesive layer 8 may be thicker than the thickness in the third direction Z of adhesive layers 7A, 7B.

[0085] By providing an adhesive layer 8 between the second portion 1F and the wiring board 3, the flexible wiring board 1 is fixed to the wiring board 3, and it is possible to suppress the spread of the flexible wiring board 1 in the third direction Z. By fixing the flexible wiring board 1 to the wiring board 3 by the adhesive layer 8, it is possible to reduce the load on the second end 1b of the flexible wiring board 1 that is connected to the connector 4.

[0086] Even with the structure of the display device DSP2 in the second embodiment, it is possible to obtain a display device DSP2 that can have a narrow frame like the first embodiment, and also to obtain the same effects as the first embodiment.

[0087] When adhesive layer 8 is provided, only adhesive layer 7A may be provided between thick portion 1B and first portion 1D, only adhesive layer 7B may be provided between first portion 1D and second portion 1F, or neither adhesive layer 7A nor 7B may be provided.

[0088] [Third embodiment] A third embodiment will be described below. The same components as those in the above-described embodiments are given the same reference numerals, and the description will be omitted as appropriate. Fig. 8 is a cross-sectional view showing a configuration example of a display device DSP3 in the third embodiment. As shown in Fig. 8, the display device DSP3 includes a display panel PNL, a flexible wiring board 1, an IC chip 2, a wiring board 3, and a light-emitting module 100. Note that the display panel PNL is illustrated in a simplified form, with only the main parts being shown.

[0089] The display device DSP3 further includes a first cover member 30, a second cover member 40, an adhesive layer AD1 that bonds the second substrate SUB2 and the first cover member 30, an adhesive layer AD2 that bonds the first substrate SUB1 and the second cover member 40, and an adhesive layer AD3 that bonds the first substrate SUB1 and the wiring substrate 3.

[0090] The flexible wiring board 1 has, between the first end 1a and the second end 1b, a first bent portion 1A, a thick portion 1B, a second bent portion 1C, and a first portion 1D, from the first end 1a side. The display device DSP3 further includes an adhesive layer 7A that bonds the thick portion 1B and the first portion 1D. The display device DSP3 in the third embodiment differs from each of the above-mentioned embodiments in that the flexible wiring board 1 does not have the third bent portion 1E and the second portion 1F.

[0091] The connector 4 is located, for example, on the side surface E31 side from the center of the main surface 3A of the wiring board 3 in the second direction Y. However, the position of the connector 4 on the main surface 3A is not limited to the example shown in the figure. The flexible wiring board 1 is bent at the second bent portion 1C, and the first portion 1D is located between the wiring board 3 and the thick portion 1B in the third direction Z. The connector 4 is located between the wiring board 3 and the thick portion 1B.

[0092] Depending on the position of the connector 4 on the main surface 3A, the flexible wiring board 1 is bent at the first bending portion 1A and the second bending portion 1C, and when the transparent substrate 10 and the wiring board 3 are connected, the width of the frame portion in the second direction Y can be reduced. Even with the structure of the display device DSP3 in the third embodiment, it is possible to obtain a display device DSP3 that can have a narrow frame like the above-mentioned embodiments. Also, it is possible to obtain the same effects as the above-mentioned embodiments.

[0093] In the example shown in Fig. 8, the width of the adhesive layer 7A in the second direction Y is approximately the same as that in the examples shown in Fig. 5 and Fig. 7, but may be wider or narrower than that in the examples shown in Fig. 5 and Fig. 7. The display device DSP3 in the third embodiment may further include an adhesive layer between the wiring substrate 3 and the first portion 1D.

[0094] All display devices that can be implemented by appropriately modifying the design based on the display device described above as an embodiment of the present invention are within the scope of the present invention as long as they include the gist of the present invention. Within the scope of the concept of the present invention, a person skilled in the art can come up with various modifications, and these modifications are also considered to be within the scope of the present invention. For example, a display device in which a person skilled in the art appropriately adds, deletes, or modifies the design of components, or adds, omits, or modifies processes, from the above-mentioned embodiment, is also included in the scope of the present invention as long as it includes the gist of the present invention.

[0095] Furthermore, with regard to other effects and advantages brought about by the aspects described in each of the above-mentioned embodiments, those which are obvious from the description in this specification or which can be appropriately conceived by a person skilled in the art are naturally understood to be brought about by the present invention. [Explanation of symbols]

[0096] DSP1, DSP2, DSP3...display device, SUB1...first substrate, SUB2...second substrate, 1...flexible wiring substrate, 3...wiring substrate, 10A...main surface (second surface), 10B...main surface (first surface), 110...light source, Ex1...extension portion, E11...side surface (first side surface), E21...side surface (second side surface), AD3...adhesive layer (first adhesive layer).

Claims

1. a first substrate having a first surface, a second surface opposite to the first surface, and a first side surface connecting the first surface and the second surface; a second substrate having a second side surface facing the first surface; a light source provided along the second side surface of the second substrate; a wiring substrate facing the second surface of the first substrate; a first adhesive layer that bonds the second surface and the wiring substrate; a flexible wiring board that electrically connects the first substrate and the wiring board; the first substrate has an extension portion that includes the first side surface and extends beyond the second side surface of the second substrate; The flexible wiring board is Mounted on the extension, a first end connected to the extending portion, a second end connected to the wiring board, a first bent portion and a second bent portion between the first end and the second end, a thick portion between the first bent portion and the second bent portion, and a first portion between the second bent portion and the second end, The first bending portion is bent toward the second surface of the first substrate, the thick portion has an overlapping portion that overlaps with the first portion in a thickness direction of the first substrate, In the overlapping portion, the thick portion is thicker than the first portion. Display device.

2. Further comprising a second adhesive layer that adheres the thick portion and the first portion. The display device according to claim 1 .

3. the flexible wiring board further includes a third bent portion between the first portion and the second end portion, and a second portion between the third bent portion and the second end portion, the second portion is located between the first portion and the wiring substrate in the thickness direction. The display device according to claim 1 .

4. Further comprising a third adhesive layer that adheres the first portion and the second portion. The display device according to claim 3 .

5. Further comprising a fourth adhesive layer that adheres the second portion to the wiring substrate. The display device according to claim 3 or 4.

6. the second end portion is connected to a side surface of the wiring substrate facing the first bent portion at a position closer to the side surface of the wiring substrate than the second bent portion is. The display device according to claim 1 .

7. a first substrate having a first surface, a second surface opposite to the first surface, and a first side surface connecting the first surface and the second surface; a second substrate having a second side surface facing the first surface; a light source provided along the second side surface of the second substrate; a wiring substrate facing the second surface of the first substrate; a first adhesive layer that bonds the second surface and the wiring substrate; A second adhesive layer; a flexible wiring board that electrically connects the first substrate and the wiring board; the first substrate has an extension portion that includes the first side surface and extends beyond the second side surface of the second substrate; The flexible wiring board is Mounted on the extension, a first end connected to the extending portion, a second end connected to the wiring board, a first bent portion and a second bent portion between the first end and the second end, a first portion between the second bent portion and the second end, and a third portion between the first bent portion and the second bent portion, the first portion has an overlapping portion overlapping with the third portion, the second adhesive layer adheres the third portion and the first portion to each other at the overlapping portion, the second end portion is connected to the wiring substrate at a position closer to a side surface of the wiring substrate facing the first bent portion than the second bent portion; In the overlapping portion, the third portion is thicker than the first portion. Display device.

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