Display device

Abstract

To provide a display device in which a display screen having a light source unit having the flexibility at an attachment position has the transparency.SOLUTION: A display device comprises: a display panel which includes a polymer dispersion type liquid crystal layer between a pair of boards; a transparent board which is arranged on at least one surface of the display panel; and a light source unit which makes light incident from a lateral surface of the transparent board. The light source unit comprises: at least one light source; at least one light guide body on which the light emitted from the light source is incident; and a support member to which at least one light source and at least one light guide body are fixed, which has the L-shaped cross-sectional shape and extends along one side of the display panel. The light source and the light guide body are arranged on different surfaces of the support member. The light source unit is fixed to the transparent board or display panel by the support member such that the light guide body is located on the lateral surface of the transparent board.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a display device structure including a display panel and a light source unit. [Background technology]

[0002] Most of the displays installed in commercially available smartphones and tablet devices do not allow the view behind them to be seen through the screen. On the other hand, display devices called so-called transparent displays have been developed that can display images, characters, figures, etc., but are transparent like window glass when no images are displayed, allowing the view behind to be seen through the screen. For example, a display device has been disclosed that includes a display panel with a polymer-dispersed liquid crystal layer and a light source unit installed along the side of the display panel, and has a transparent display screen (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-033043 Summary of the Invention [Problem to be solved by the invention]

[0004] In a transparent display, a light source unit is disposed on the side of the display panel so that the viewer can see what is behind it through the screen. The transparent display disclosed in Patent Document 1 has a structure in which a light source unit, in which a light-emitting diode (LED) and a lens unit are mounted on a wiring board, is attached to a glass substrate that constitutes the display panel, and light is irradiated from the side of the display panel. However, this light source unit attachment structure has a problem in that the position where the light source unit can be fixed is limited.

[0005] In view of the above problem, an embodiment of the present invention has an object to provide a display device having a transparent display screen and including a light source unit that has flexibility in its mounting position. [Means for solving the problem]

[0006] A display device according to one embodiment of the present invention includes a display panel including a polymer-dispersed liquid crystal layer between a pair of substrates, a transparent substrate disposed on at least one surface of the display panel, and a light source unit that receives light from a side surface of the transparent substrate. The light source unit includes at least one light source, at least one light guide into which light emitted from the light source is incident, and a support member to which the at least one light source and the at least one light guide are fixed, the support member having an L-shaped cross section and extending along one side of the display panel, the light source and the light guide being disposed on different surfaces of the support member. The light source unit is fixed to the transparent substrate or the display panel by the support member so that the light guide is located on the side surface of the transparent substrate. [Brief explanation of the drawings]

[0007] [Figure 1] 1A and 1B show the configuration of a light source unit used in a display device according to one embodiment of the present invention, in which FIG. 1A is a plan view and FIG. 1B is a front view. [Figure 2] 1A and 1B show the configuration of a light source unit used in a display device according to one embodiment of the present invention, in which (A) is a side view and (B) is a plan view. [Figure 3] 1A and 1B show a configuration of a light source unit used in a display device according to one embodiment of the present invention, with (A) and (B) being side views. [Figure 4] 1 shows a configuration of a display panel used in a display device according to one embodiment of the present invention. [Figure 5] 1 shows a cross-sectional structure of a display section in a display panel used in a display device according to one embodiment of the present invention. [Figure 6] 1 is a cross-sectional view showing the configuration of a display device according to one embodiment of the present invention. [Figure 7] 1 is a plan view showing a configuration in the vicinity of a light source unit of a display device according to an embodiment of the present invention. [Figure 8] 1 is a cross-sectional view showing the configuration of a display device according to one embodiment of the present invention. [Figure 9] 1 is a cross-sectional view showing the configuration of a display device according to one embodiment of the present invention. [Figure 10] 1 is a cross-sectional view showing the configuration of a display device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention can be implemented in many different forms, and should not be construed as being limited to the description of the embodiments exemplified below. For clarity of explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual form, but these are merely examples and do not limit the interpretation of the present invention. Furthermore, in this specification and each drawing, elements similar to those previously described with reference to the previous drawings are designated by the same reference numerals (or reference numerals with a, b, etc. suffixed thereto), and detailed descriptions may be omitted as appropriate. Furthermore, the letters "first" and "second" attached to each element are convenient labels used to distinguish each element and have no further meaning unless otherwise specified.

[0009] In this specification, when a component or region is described as being "on (or under)" another component or region, unless otherwise specified, this includes not only the case where it is directly above (or directly under) the other component or region, but also the case where it is above (or under) the other component or region, i.e., the case where another component is included between the component or region and above (or under) the other component or region.

[0010] 1. Light source unit The configuration of a light source unit provided in a display device according to one embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1(A) shows a plan view of the light source unit 102, and Fig. 1(B) shows a front view of the light source unit 102. The light source unit 102 includes at least one light source 110, at least one light guide 112, and a support member 114.

[0011] The support member 114 has an L-shaped cross section and extends in one direction along one side of a display panel (not shown). The support member 114 includes a flat plate-like portion, which can be divided into two sections: a first flat plate section 1141 and a second flat plate section 1142. Note that the first flat plate section 1141 and the second flat plate section 1142 do not mean that the support member 114 is formed from two members, but these names are used to describe the sections of the support member 114. The support member 114 having an L-shaped cross section may be made by bending a flat plate, may be extruded, or may be made by joining two plates, and is not limited to any particular manufacturing method.

[0012] 1A and 1B show a light source unit 102 in which at least one light source 110 is composed of multiple light sources 110 and arranged along the longitudinal direction of a support member 114. The multiple light sources 110 are mounted on a first wiring board 116 and attached to the support member 114. The first wiring board 116 is, for example, a printed wiring board (PCB) or a flexible wiring board (FPC). The first wiring board 116, with the multiple light sources 110 mounted thereon, is adhered to a first flat plate portion 1141 of the support member 114 by a first adhesive layer 118. Also, FIGS. 1A and 1B show a light source unit 102 in which at least one light guide 112 is composed of multiple light guides 112 and arranged along the longitudinal direction of the support member 114. Each of the multiple light guides 112 is fixed to the support member 114 by a second adhesive layer 120. As described above, the light source unit 102 according to this embodiment has a structure in which a plurality of light sources 110 and a plurality of light guides 112 are arranged in one direction on the support member 114 that extends in one direction.

[0013] The plurality of light sources 110 includes a light source that emits red light, a light source that emits green light, and a light source that emits blue light. The light sources 110 corresponding to each color are arranged along the longitudinal direction of the support member 114. For example, light-emitting diodes (hereinafter also referred to as "LEDs") are used as the plurality of light sources 110. In this embodiment, the LEDs used as the plurality of light sources 110 are preferably so-called top-view LEDs that emit light from the surface opposite to the surface mounted on the first wiring substrate 116. Using top-view LEDs allows the light source 110 to be made thinner and the intensity of the emitted light to be increased. This allows the light source unit 102 according to this embodiment to be applied to a large-screen display device.

[0014] If the display device is not intended for color display, a monochromatic light source or a white light source may be used as the light source 110. The light source 110 may be a module in which multiple LED chips are modularized into a single component. Alternatively, the light source 110 may be a cold cathode fluorescent lamp.

[0015] As shown in FIG. 1A, the light guide 112 has a light incident surface 1121 and a light exit surface 1122. Light emitted from the light source 110 enters the light incident surface 1121 of the light guide 112 and exits from the light exit surface 1122. The light guide 112 has a light guide path between the light incident surface 1121 and the light exit surface 1122, and has the function of diffusing the incident light in the light guide path, homogenizing the intensity distribution, and emitting the light from the light exit surface 1122. At least one light guide 112 may be composed of multiple light guides 112. FIGS. 1A and 1B show an embodiment in which multiple light guides 112 are bonded to a second flat plate portion 1142 of a support member 114 and arranged along the longitudinal direction. The multiple light sources 110 and the multiple light guides 112 do not necessarily have a one-to-one relationship; one light guide 112 may be arranged for multiple light sources 110.

[0016] 1(A) and 1(B) show a structure in which a plurality of light sources 110 are arranged in one direction, but the present invention is not limited to such a structure, and a light source in which the light emitting section is integrated and can be regarded as substantially one may be used. Also, while Figs. 1(A) and 1(B) show a structure in which a plurality of light guides 112 are arranged in one direction, the present invention is not limited to such a structure, and a single light guide 112 extending in one direction may be used.

[0017] The length of the light source unit 102 is arbitrary and corresponds to one side of the display panel to which it is attached. The number of the light sources 110 and the number of the light guides 112 can be set appropriately according to the length of the light source unit 102.

[0018] Next, the light source unit 102A will be described in detail with reference to Figures 2(A) and 2(B). Figure 2(A) shows a cross-sectional view of the light source unit 102A according to this embodiment, and Figure 2(B) shows a partial plan view of the light source unit 102A.

[0019] 2(A) and (B) show the case where the light source 110 is a top-view LED. The top-view LED has a mounting surface that is attached to the first wiring substrate 116 and a light-emitting surface 1101 opposite the mounting surface. The top-view LED is thinner than a side-view LED in which the light-emitting surface is formed on the side surface of the LED chip, and is characterized by high emitted light intensity.

[0020] The light guide 112 has a light incident surface 1211 and a light exit surface 1122, and has the property of guiding light while reflecting it inside the body, and making the intensity of the incident light uniform. The light guide 112 is formed using a transparent resin material such as acrylic or polycarbonate. The light incident surface 1211, the light exit surface 1122, and the light guide section between the light incident surface 1211 and the light exit surface 1122 may be integrally formed using the above materials.

[0021] The support member 114 has an L-shaped cross section and includes a first flat plate portion 1141 extending in a first direction from a bent portion and a second flat plate portion 1142 extending in a second direction intersecting the first direction. The first flat plate portion 1141 has a first surface PS1 and a third surface PS3 opposite the first surface PS1, and the second flat plate portion 1142 has a second surface PS2 and a fourth surface PS4 opposite the second surface PS2. In other words, the support member 114 has the first surface PS1 and the second surface PS2 as inner surfaces that are bent into an L shape, and the third surface PS3 and the fourth surface PS4 as outer surfaces.

[0022] In this embodiment, the cross-sectional shape of the support member 114 is referred to as an L-shape for convenience. However, the cross-sectional shape of the support member 114 is not limited to a so-called L-shape, and may be expressed as an L-shape, a mountain shape, a bent shape, or the like.

[0023] 2(A) shows a structure in which the light source 110 is disposed on a first surface PS1 of the support member 114, and the light guide 112 is disposed on a second surface PS2 of the support member 114. In this manner, the light source 110 and the light guide 112 are disposed on different surfaces of the support member 114. The first surface PS1 is the surface on which the light source 110 is attached, and the second surface PS2 is the surface on which the light guide 112 is installed. The position and angle of the light source 110 are determined by the first surface PS1, and the position and angle of the light guide 112 are determined by the second surface PS2. Since the light emission surface 1101 of the light source 110 and the light incidence surface 1121 of the light guide 112 face each other in parallel, it is preferable that the normal direction of the first surface PS1 and the normal direction of the second surface PS2 be orthogonal to each other.

[0024] The support member 114 is made of a metal material or a plastic material. The metal material is preferably a lightweight metal material such as aluminum, an aluminum alloy, or titanium, a titanium alloy. The plastic material is preferably a hard plastic material.

[0025] The light source 110 is mounted on the first surface PS1 of the first wiring board 116. Specifically, the surface of the first wiring board 116 opposite to the mounting surface (the surface on which the light source 110 is mounted) serves as an adhesive surface, and is adhered to the first surface PS1 of the support member 114. The first wiring board 116 is adhered to the first surface PS1 of the support member 114 by a first adhesive layer 118. The first wiring board 116 is formed of a glass epoxy material or a polyimide material. The first wiring board 116 has wiring that supplies power to the light source 110. Although not shown, an integrated circuit that forms a control circuit, a power supply circuit, etc. that controls the light emission of the light source 110 may be mounted on the first wiring board 116.

[0026] A slit-shaped through-hole 124 is provided in the support member 114. The through-hole 124 is provided near a bending portion of the support member 114. For example, the through-hole 124 is provided in the second flat plate portion 1142, near the L-shaped bending portion of the support member 114. The through-hole 124 is provided so as to penetrate from the second surface PS2 to the fourth surface PS4 of the second flat plate portion 1142. As shown in FIG. 2(B), the slit-shaped through-hole 124 is provided along the longitudinal direction of the support member 114.

[0027] First wiring board 116 is inserted into through-hole 124. By providing through-hole 124 in support member 114, first wiring board 116 can be pulled out to the outside while still attached to first surface PS1.

[0028] The light guide 112 is bonded to the second surface PS2 of the support member 114. A second adhesive layer 120 is provided between the light guide 112 and the support member 114. Because the cross section of the support member 114 is L-shaped, the light incident surface 1121 of the light guide 112 can be disposed to face the light exit surface 1101 of the light source 110. That is, because the cross section of the support member 114 is L-shaped and the normal direction of the first surface PS1 and the normal direction of the second surface PS2 are orthogonal to each other, the light exit surface of the light source 110 can be disposed to face the light incident surface 1201 of the light guide 112 in parallel with each other. Furthermore, because the cross section of the support member 114 is L-shaped, the height of the light source 110 can be adjusted to match the light incident surface 1121 of the light guide 112.

[0029] The third surface PS3 and the fourth surface PS4 of the support member 114 can be used as adhesive surfaces for attaching the light source unit 102A. That is, when attaching the light source unit 102A along the side surface of the display panel, the third surface PS3 or the fourth surface PS4 of the support member 114 can be used as an adhesive surface. Which of the third surface PS3 and the fourth surface PS4 is to be used as the adhesive surface can be selected appropriately depending on the shape of the display panel and the shape of the housing surrounding the display panel.

[0030] When attaching the light source unit 102A to the display panel, a third adhesive layer 122 is provided. The third adhesive layer 122 is preferably formed of a thin adhesive or pressure-sensitive adhesive. FIGS. 2(A) and 2(B) show, as an example, a structure in which the fourth surface PS4 is used as the adhesive surface and the third adhesive layer 122 is provided on this surface. The fourth surface PS4 is a flat surface extending along the longitudinal direction of the support member 114. By using this surface as the adhesive surface, the adhesive surface extends over the entire length of the support member 114, allowing the light source unit 102A to be stably adhered to the target location. The same applies when the third surface PS3 is used as the adhesive surface.

[0031] 3A and 3B show another example of a light source unit according to an embodiment of the present invention. The light source unit 102B shown in Fig. 3A and the light source unit 102C shown in Fig. 3B have an L-shaped cross section similar to the light source unit 102A shown in Fig. 2A, but the detailed shape of the support member 114 is different.

[0032] In the light source unit 102B shown in FIG. 3(A), the cross section of the support member 114 is L-shaped, and the second flat plate portion 1142 forming the second surface PS2 and the fourth surface PS4 extends forward beyond the end of the light guide 112. That is, the support member 114 shown in FIG. 3(A) has a shape in which the second flat plate portion 1142 protrudes outward beyond the end of the light guide 112. In the support member 114 having such a shape, the second surface PS2 on which the light guide 112 is disposed can be used as an adhesive surface. That is, the second surface PS2, which is an extended portion of the second flat plate portion 1142 and is the same surface on which the light guide 112 is disposed, can be used as an adhesive surface. Alternatively, the fourth surface PS4 can be used as an adhesive surface, in which case the area of ​​the adhesive surface can be increased.

[0033] In the light source unit 102C shown in FIG. 3(B), the cross section of the support member 114 is L-shaped, and the first flat plate portion 1141 forming the first surface PS1 and the third surface PS3 has a shape that extends upward. That is, the support member 114 shown in FIG. 3(B) has a shape in which the first flat plate portion 1141 protrudes outward beyond the end of the light source 110. In the support member 114 having such a shape, the first surface PS1 on which the light source 110 is disposed can be used as the bonding surface. That is, the first surface PS1, which is an extended portion of the first flat plate portion 1141 and is the same surface on which the light source 110 is disposed, can be used as the bonding surface. Alternatively, the third surface PS3 can be used as the bonding surface, in which case the area of ​​the bonding surface can be increased.

[0034] As described above, the light source units 102A, 102B, and 102C according to this embodiment have a high degree of freedom in terms of the position of the adhesive surface (mounting surface) because the cross section of the support member 114 is L-shaped. This allows the light source unit 102 to be mounted to the display panel in various ways.

[0035] 2. Display panel FIG. 4 shows the configuration of the display panel 104. The display panel 104 includes a first substrate 130 and a second substrate 132. A display unit 136 and a terminal unit 138 are provided on the first substrate 130, and the second substrate 132 is provided to overlap the display unit 136. The display unit 136 has a structure in which a plurality of pixels 150 are arranged. The plurality of pixels 150 may have a structure compatible with an active matrix driving method driven by thin film transistors, or may have a structure compatible with a passive matrix driving method in which electrodes are arranged vertically and horizontally in a grid pattern. FIG. 4 shows a case in which the plurality of pixels 150 are driven by an active matrix driving method. Scanning signal lines 141 and data signal lines 143 are arranged in the display unit 136.

[0036] A scanning signal line driving circuit 140 and a data signal line selection circuit 142 may be provided in an area (peripheral area) outside the display unit 136. A terminal unit 138 is provided at an end of the first substrate 130 exposed from the second substrate 132. A plurality of terminals 148 are arranged in the terminal unit 138. A second wiring substrate 146 is connected to the terminal unit 138. The second wiring substrate 146 is, for example, a flexible wiring substrate (FPC). A driver IC 144 may be mounted on the second wiring substrate 146. The driver IC 144 has a function of outputting signals, such as video signals, that drive the display panel 104. The driver IC 144 may also be mounted on the first substrate 130.

[0037] Fig. 5 shows a partial cross-sectional structure of a display unit 136 in the display panel 104. As shown in Fig. 5, the display panel 104 includes a first substrate 130, a second substrate 132, and a liquid crystal layer 152 between the first substrate 130 and the second substrate 132. For example, glass substrates are used for the first substrate 130 and the second substrate 132, but a plastic substrate or a flexible film substrate may also be used.

[0038] A first electrode 156 is provided on the first substrate 130, and a second electrode 158 is provided on the second substrate 132. The first electrode 156 is provided for each pixel 150, and the second electrode 158 is provided commonly to multiple pixels 150. A thin film transistor 166 is formed on the first substrate 130. The thin film transistor 166 is provided for each of the multiple pixels 150. The first electrode 156 is provided on the thin film transistor 166 via an interlayer insulating film 160. The first electrode 156 is electrically connected to the thin film transistor 166 via a contact hole formed in the interlayer insulating film 160. The voltage of the first electrode 156 is controlled by the thin film transistor 166. A constant voltage is applied to the second electrode 158 commonly to each pixel. With this configuration, the state of voltage application to the liquid crystal layer 152 is controlled individually for each pixel 150.

[0039] A first alignment film 162 is provided to cover the first electrode 156, and a second alignment film 164 is provided to cover the second electrode 158. A liquid crystal layer 152 is provided between the first alignment film 162 and the second alignment film 164. The liquid crystal layer 152 includes a polymer dispersed liquid crystal. Specifically, the liquid crystal layer 152 has a structure in which polymer layers 153 and polymer dispersed liquid crystal layers 154 are alternately stacked.

[0040] Polymer layer 153 includes a liquid crystal polymer. Polymer dispersed liquid crystal layer 154 includes a polymer dispersed liquid crystal. Polymer layer 153 and polymer dispersed liquid crystal layer 154 have optical anisotropy or refractive index anisotropy. When a high voltage equal to or greater than a threshold voltage is applied to first electrode 156, the alignment direction of the liquid crystal molecules in polymer dispersed liquid crystal layer 154 changes depending on the magnitude of the voltage. In a state where a voltage equal to or greater than the threshold voltage is not applied to liquid crystal layer 152 (a state where a voltage equal to or greater than the threshold voltage is not applied to first electrode 156), the optical axes of polymer layer 153 and polymer dispersed liquid crystal layer 154 are parallel to each other, and light incident on liquid crystal layer 152 is transmitted with almost no scattering (this state is referred to as the "transparent mode"). On the other hand, when a voltage equal to or greater than the threshold voltage is applied to the liquid crystal layer 152 (when a voltage equal to or greater than the threshold voltage is applied to the first electrode 156), the optical axes of the liquid crystal molecules in the polymer layer 153 and the polymer dispersed liquid crystal layer 154 intersect with each other, and light incident on the liquid crystal layer 152 is scattered (this state is referred to as the "scattering mode").

[0041] In the display panel 104, the state (transmission mode or scattering mode) of the liquid crystal layer 152 is controlled by a voltage (a voltage based on a video signal) applied to each of the plurality of pixels 150. The display panel 104 displays images, characters, figures, etc. on the display unit 136 by individually controlling the state of voltage application to the plurality of pixels 150. For example, when all of the plurality of pixels 150 are in the transmission mode, the display unit 136 becomes transparent, allowing the back surface of the display panel 104 to be seen through. On the other hand, when some of the plurality of pixels 150 are in the scattering mode and the other pixels 150 are in the transmission mode, any image, character, figure, etc. can be displayed on the display unit 136 by changing the contrast.

[0042] 3.Display device Next, the configuration of a display device 100 including a light source unit 102 described in Section 1 and a display panel 104 described in Section 2 will be described.

[0043] 3-1. First embodiment 6 shows a cross-sectional view of a display device 100A according to the first embodiment. The display device 100A includes a display panel 104, a first transparent substrate 106, a second transparent substrate 108, and a light source unit 102A. As described with reference to FIGS. 4 and 5, the display panel 104 includes a first substrate 130, a second substrate 132, a liquid crystal layer 152, and a second wiring substrate 146. The display panel 104 has a display unit 136. Details of the display unit 136 are similar to those described with reference to FIG. 5.

[0044] The first transparent substrate 106 is disposed on the first substrate 130 side of the display panel 104, and the second transparent substrate 108 is disposed on the second substrate 132 side. The first transparent substrate 106 and the second transparent substrate 108 are, for example, glass substrates, but plastic substrates may also be used. The first transparent substrate 106 and the second transparent substrate 108 preferably have refractive indices equivalent to those of the first substrate 130 and the second substrate 132 that constitute the display panel 104.

[0045] The first substrate 130 of the display panel 104 has a first surface S11 and a second surface S12 opposite the first surface S11, and the second substrate 132 has a first surface S21 and a second surface S22 opposite the first surface S21. The first surface S11 of the first substrate 130 faces the liquid crystal layer 152, and the second surface S12 is a surface facing the first transparent substrate 106. The first surface S21 of the second substrate 132 faces the liquid crystal layer 152, and the second surface S22 is a surface facing the second transparent substrate 108.

[0046] The first transparent substrate 106 has a first surface C11, a second surface C12 opposite the first surface C11, a first side surface CS11, and a second surface C12 opposite the first side surface. The second transparent substrate 108 has a first surface C21, a second surface C22 opposite the first surface C21, a first side surface CS21, and a second side surface CS22 opposite the first side surface.

[0047] The second surface C12 of the first transparent substrate 106 and the first surface S11 of the first substrate 130 are disposed to face each other and are bonded together with a first transparent adhesive layer 126. The first surface C21 of the second transparent substrate 108 and the second surface S22 of the second substrate 132 are disposed to face each other and are bonded together with a second transparent adhesive layer 128. The first transparent substrate 106 and the second transparent substrate 108 are disposed to sandwich at least the display unit 136. The first transparent adhesive layer 126 and the second transparent adhesive layer 128 preferably have refractive indices equivalent to those of the first transparent substrate 106 and the second transparent substrate 108, and the first substrate 130 and the second substrate 132. Note that "equivalent refractive indices" does not necessarily mean that the difference in refractive index is zero, but also includes a difference in refractive index of 0.03 or less.

[0048] The first substrate 130 has an area overlapping with the second substrate 132 and an area protruding from the second substrate 132. A liquid crystal layer 152 is provided in the area where the first substrate 130 and the second substrate 132 face each other and overlap. A display unit 136 is formed in the area where the liquid crystal layer 152 is provided. A terminal unit 138 is provided in the area where the first substrate 130 protrudes from the second substrate 132. The terminal unit 138 is formed on the first surface S11 of the first substrate 130. A second wiring substrate 146 is attached to the terminal unit 138. The first transparent substrate 106 is disposed from the second surface S12 side of the first substrate 130 so as to overlap with the display unit 136. The first transparent substrate 106 is sized so as not to extend to the protruding portion of the first substrate 130 (the area where the terminal unit 138 is formed). Therefore, the first substrate 130 has an area where the first transparent substrate 106 does not overlap and where the second surface S12 is exposed.

[0049] The light source unit 102A is attached to the second surface S12 of the first substrate 130 exposed from the first transparent substrate 106. The fourth surface PS4 of the support member 114 serves as an adhesive surface for the light source unit 102A. The light source unit 102A is disposed so that the fourth surface PS4 faces the second surface S12 of the first substrate 130, and is adhered thereto by a third adhesive layer 122. With the light source unit 102A attached to the first substrate 130, the light exit surface 1122 of the light guide 112 is disposed so as to face the first side surface CS11 of the first transparent substrate 106.

[0050] The light source unit 102A can be attached to the display panel 104 at one location on the fourth surface PS4 because the light source 110 and the light guide 112 are modularized by the support member 114. The alignment between the light emission surface 1122 of the light guide 112 and the first side surface CS11 of the first transparent substrate 106 can be adjusted by the attachment position of the support member 114. In other words, because the relative positions of the light source 110 and the light guide 112 are determined by the support member 114, it is not necessary to individually adjust the positions of the light source 110 and the light guide 112 and the first side surface CS11 of the first transparent substrate 106 when attaching the light source unit 102A to the display panel 104.

[0051] In the display device 100A shown in FIG. 6, the light source unit 102A is attached to the surface (second surface S12) opposite the terminal portion 138 of the first substrate 130, so that the first wiring substrate 116 on which the light source 110 is mounted can be pulled out in the same direction as the second wiring substrate 146 attached to the terminal portion 138.

[0052] The display device 100A shown in FIG. 6 can display images, characters, figures, and the like using light emitted from a light source unit 102A. A light source 110 provided in the light source unit 102A emits light to a light guide 112. The light incident on the light guide 112 is emitted from a light emitting surface 1122 and enters the first transparent substrate 106 from a first side surface CS11. The light incident on the first transparent substrate 106 propagates through the display panel 104 while being repeatedly reflected. Light passing through pixels to which no voltage is applied is transmitted with almost no scattering by the liquid crystal layer 152. Meanwhile, light incident on pixels to which voltage is applied is scattered by the liquid crystal layer 152. As a result, there is a large difference in contrast between pixels through which light is transmitted and pixels through which light is scattered, allowing a viewer to view images, characters, figures, and the like displayed on the display unit 136.

[0053] FIG. 7 shows a partial plan view of the display device 100A as viewed from the first transparent substrate 106 side. In FIG. 7, a light source unit 102A is attached to a display panel 104. The light source unit 102A is provided with a plurality of light sources 110. The plurality of light sources 110 includes a first light source 110a of a first emitted color, a second light source 110b of a second emitted color, and a third light source 110c of a third emitted color. For example, the first emitted color corresponds to red, the second emitted color corresponds to green, and the third emitted color corresponds to blue. In this manner, the light source unit 102A has a structure in which the first light source 110a, the second light source 110b, and the third light source 110c, each emitting a single color, are arranged in the longitudinal direction of the support member 114.

[0054] The display device 100A is driven by a field sequential method. The display device 100A breaks down one frame of a video signal into fields equal to the number of monochromatic light sources, or fields equal to an integer multiple of the number of monochromatic light sources, and sequentially displays the fields on the display panel 104. The light source unit 102A emits light from a monochromatic light source corresponding to the color component of each field in accordance with the field frequency. This driving method makes it possible to display a color image without using a color filter. In other words, by driving the display device 100A by the field sequential method, it is possible to display a color image while maintaining the transparent state of the display unit 136.

[0055] The display unit 136 of the display device 100A can be observed from both the first transparent substrate 106 side and the second transparent substrate 108 side. When no voltage is applied to the liquid crystal layer 152, the background can be seen through the display unit 136 from the first transparent substrate 106 side, and the background can also be seen through the display unit 136 from the second transparent substrate 108 side. In other words, the display device 100A according to the first embodiment can be used as a transparent display.

[0056] The display device 100A shown in FIG. 6 can use a high-output top-view LED for the light source unit 102A. This allows high-contrast images to be displayed even though it is a transparent display. Furthermore, it can accommodate larger display units 136 (display screens). The light source unit 102A uses a support member 114 with an L-shaped cross section, which allows the light source 110 and light guide 112 to be housed compactly and allows the relative positions of the light source 110 and light guide 112 to be precisely positioned.

[0057] 3-2. Second embodiment 8 shows a cross-sectional view of a display device 100B according to the second embodiment. The display device 100B includes a display panel 104, a first transparent substrate 106, a second transparent substrate 108, and a light source unit 102B. The configuration of the display panel 104 is the same as that in the first embodiment. The arrangement of the first transparent substrate 106 and the second transparent substrate 108 is also the same as that in the first embodiment.

[0058] 8 has a structure in which a light source unit 102B is attached to a first transparent substrate 106 and light is incident from the second side surface CS12 side. The light source unit 102B is arranged so that the second surface PS2 of the support member 114 serves as an adhesive surface and faces the first surface C11 of the first transparent substrate 106. The support member 114 is adhered to the first surface C11 of the first transparent substrate 106 by a third adhesive layer 122. With the light source unit 102B attached to the first transparent substrate 106, the light exit surface 1122 of the light guide 112 is positioned so as to face the second side surface CS12 of the first transparent substrate 106.

[0059] 9 has a structure in which a light source unit 102B is attached to the second transparent substrate 108 and light is incident from the first side surface CS21 side. The light source unit 102B is arranged so that the second surface PS2 of the support member 114 serves as an adhesive surface and faces the second surface C22 of the second transparent substrate 108. The support member 114 is adhered to the second surface C22 of the second transparent substrate 108 by a third adhesive layer 122. With the light source unit 102B attached to the second transparent substrate 108, the light exit surface 1122 of the light guide 112 is positioned so as to face the first side surface CS21 of the second transparent substrate 108.

[0060] 9, second transparent substrate 108 extends to an area overlapping terminal portion 138 of display panel 104, and this portion is used as an adhesive surface for light source unit 102B. In other words, by making second transparent substrate 108 protrude outward from second substrate 132, light source unit 102B can be attached without affecting display portion 136.

[0061] 8 and 9, the light source unit 102B has a support member 114 modularizing the light source 110 and the light guide 112, and the second flat plate portion 1142 has an extended region. The light source unit 102B can be attached to the first transparent substrate 106 or the second transparent substrate 108 by utilizing the extended region of the support member 114. The area of ​​the extended region of the support member 114, i.e., the area of ​​the adhesive surface, can be adjusted as needed. By increasing the area of ​​the adhesive surface, the light source unit 102B can be firmly attached.

[0062] The mechanism by which the display device 100B displays images, characters, figures, etc. is the same as in the first embodiment. The display device 100B shown in Figures 8 and 9 can be used as a transparent display, similar to the display device 100A shown in the first embodiment.

[0063] 3-3. Third embodiment 10 shows a cross-sectional view of a display device 100C according to a third embodiment. The display device 100C includes a display panel 104, a first transparent substrate 106, a second transparent substrate 108, and a light source unit 102C. The configuration of the display panel 104 is the same as that in the first embodiment. The arrangement of the first transparent substrate 106 and the second transparent substrate 108 is also the same as that in the first embodiment.

[0064] 10 has a structure in which a light source unit 102C is attached to a side surface of a display panel 104. The light source unit 102C has a first surface PS1 of a support member 114 as an adhesive surface, and is provided so that a portion extending outward from an area in which the light source 110 is arranged faces the side surface of the display panel 104.

[0065] The display panel 104 has a shape in which the edges of the first substrate 130 and the second substrate 132 protrude outward from the region sandwiched between the first transparent substrate 106 and the second transparent substrate 108. The regions in which the first substrate 130 and the second substrate 132 protrude from the first transparent substrate 106 and the second transparent substrate 108 are non-display regions. Although not shown in detail in Figure 10, the non-display region of the display panel 104 does not need to be provided with a liquid crystal layer, and a drive circuit may be provided in this region.

[0066] The light source unit 102C is disposed such that the first surface PS1 of the support member 114 is bonded to the edge surface of the display panel 104 via the third adhesive layer 122, and the light exit surface 1122 of the light guide 112 faces the second side surface CS22 of the second transparent substrate 108. With this arrangement, light emitted from the light source 110 can be introduced into the display panel 104. As shown in FIG. 10 , by using the side surface of the display panel 104 as an attachment portion for the light source unit 102C, the light source unit 102C can be installed without affecting the display section 136.

[0067] Although not shown, the light emitting surface 1122 of the light guide 112 may be disposed so as to face the second side surface CS12 of the first transparent substrate 106. Alternatively, the first flat plate portion 1141 of the support member 114 may be further extended so that the first surface PS1 faces the second side surface CS12 of the first transparent substrate 106, and a third adhesive layer 122 may be provided on this facing portion to attach the light source unit 102C.

[0068] The mechanism by which the display device 100B displays images, characters, figures, etc. is the same as in the first embodiment. The display device 100C shown in Fig. 10 can be used as a transparent display, similar to the display device 100A shown in the first embodiment.

[0069] 3-4. Fourth embodiment 6, in addition to the light source unit 102B arranged on the first side surface CS11 side, a similar light source unit 102B may also be arranged on the second side surface CS12 side. That is, the light source units 102B may be arranged on both side surfaces of the first transparent substrate 106.

[0070] 9, in addition to the light source unit 102B arranged on the first side surface CS21 side, a similar light source unit 102B may also be arranged on the second side surface CS22 side. That is, the light source units 102B may be arranged on both side surfaces of the second transparent substrate 108.

[0071] As described above, by arranging light source units 102B on both side surfaces of first transparent substrate 106 or second transparent substrate 108, it is possible to improve the in-plane luminance uniformity even when the display panel is large.

[0072] Based on the first to fourth embodiments described above as embodiments of the present invention, those skilled in the art may add or delete components or modify the design as appropriate, and such addition or deletion of components or modifications of the design are also included within the scope of the present invention as long as they incorporate the gist of the present invention. Even if there are other effects and advantages different from those provided by the above-described embodiments, those that are clear from the description in this specification or that can be easily predicted by those skilled in the art are naturally considered to be provided by the present invention. [Explanation of symbols]

[0073] 100: display device, 102: light source unit, 104: display panel, 106: first transparent substrate, 108: second transparent substrate, 110: light source, 1101: light exit surface, 112: light guide, 1121: light incident surface, 1122: light exit surface, 114: support member, 1141: first flat plate portion, 1142: second flat plate portion, 116: first wiring substrate, 118: first adhesive layer, 120: second adhesive layer, 122: third adhesive layer, 124: through hole, 126: first transparent adhesive layer, 128: second transparent adhesive layer, 130: first substrate, 132: second substrate, 136: display section, 138: terminal section, 140: scanning signal line drive circuit, 141: scanning signal line , 142: Data signal line selection circuit, 143: Data signal line, 144: Driver IC, 146: Second wiring board, 148: Terminal, 150: Pixel, 152: Liquid crystal layer, 153: Polymer layer, 154: Polymer dispersed liquid crystal layer, 156: First electrode, 158: Second electrode, 160: Interlayer insulating film, 162: First alignment film, 164: Second alignment film, 166: Thin film transistor, CS11: First side, CS12: Second side, CS21: First side, CS22: Second side, PS1: First surface, PS2: Second surface, PS3: Third surface, PS4: Fourth surface, S11: First surface, S12: Second surface, S21: First surface, S22: Second surface

Claims

1. a display panel including a polymer dispersed liquid crystal layer between a pair of substrates; a transparent substrate disposed on at least one surface of the display panel; a light source unit that allows light to be incident from a side surface of the transparent substrate; and The light source unit is at least one light source; At least one light guide onto which light emitted by the light source is incident; a support member to which the at least one light source and the at least one light guide are fixed, the support member having an L-shaped cross section, and extending along one side of the display panel; the light source and the light guide are disposed on different surfaces of the support member, the light source unit is fixed to the transparent substrate or the display panel by the support member so that the light guide is located on a side surface of the transparent substrate; the support member has a first flat plate portion extending in a first direction from a bent portion of the L-shaped cross section in a cross-sectional view, and a second flat plate portion extending in a second direction intersecting the first direction, the at least one light source is disposed on the first flat plate portion, and the at least one light guide is disposed on the second flat plate portion; The light source unit is bonded to the display panel via an adhesive surface that is the opposite surface of the second flat plate portion of the support member from the surface on which the light guide is disposed, or the same surface as the surface on which the light source is disposed of the first flat plate portion of the support member. A display device characterized by:

2. the at least one light source is composed of a plurality of light sources, and is arranged on the first flat plate portion in a direction in which the support member extends; The display device according to claim 1 , wherein the at least one light guide is made up of a plurality of light guides, and the plurality of light guides are arranged on the second flat plate portion in a direction in which the support member extends.

3. 3. The display device according to claim 2, wherein the plurality of light sources include a first light source of a first light emission color, a second light source of a second light emission color different from the first light emission color, and a third light source of a third light emission color different from the first light emission color and the second light emission color.

4. 4. The display device according to claim 3, wherein the light source unit sequentially turns on the first light source, the second light source, and the third light source, and the display panel displays a color image by a field sequential method.

5. 5. The display device according to claim 1, wherein the light source is mounted on a flexible wiring board, and the flexible wiring board is led out through a slit-shaped through-hole formed in the support member.

6. The display device according to claim 1 , wherein the display panel has a display section in which a plurality of pixels are arranged, and the display section is transparent.

Images