Display device and optical film

Abstract

To provide a display device and an optical film capable of performing vivid reflective display without deteriorating luminance.SOLUTION: A display device comprises an optical film, and a display panel arranged on a back side of the optical film. The optical film is integrated with a colored semi-transmissive member and a first linear polarizer or a louver film having patterned light-absorbing and light-transmitting parts, which is arranged on the back side of the colored semi-transmissive member. The semi-transmissive member transmits part of light incident from the back side and reflects part of light incident from an observer side opposite the back side.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a display device and an optical film. [Background technology]

[0002] Conventional display devices typically display a desired image on the display screen when lit, and the display screen remains black when unlit. In recent years, efforts have been made to improve the design by making the display screen blend in with the surrounding components and housing when unlit, making the display screen less noticeable.

[0003] As a method for making the display screen less noticeable when it is not lit, for example, a method is being considered in which a semi-transparent member such as a screen or decorative film that transmits part of the light is placed on the front side of the display panel (for example, Patent Documents 1 and 2, etc.).

[0004] Patent document 1 discloses a display device having a display that is fitted into an attachment portion and emits display light to the outside when lit, characterized in that the front of the display is covered with a screen having a large number of fine holes that can transmit the display light, and the surface of the screen is set to the same color and pattern as the attachment portion around the display.

[0005] Patent Document 2 discloses a display device with a decorative sheet, which comprises a display device having a display surface and a decorative sheet arranged opposite the display surface, wherein the decorative sheet has a picture portion and a plurality of transparent portions which are non-forming portions of the picture portion, has an aperture ratio of 5% or more and 50% or less, and the transparent portions are formed so that the distance between adjacent transparent portions is 40 μm or more and 140 μm or less, and wherein the display device is a dot matrix liquid crystal display, and the pitch of the transparent portions is larger than the pitch of the pixels on the display surface. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-331132 [Patent Document 2] Patent No. 6696014 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-250025 [Patent Document 4] Patent No. 4622434 [Patent Document 5] Patent No. 2568882 [Patent Document 6] Patent No. 3492693 Summary of the Invention [Problem to be solved by the invention]

[0007] When the display device is turned off, the viewer visually recognizes the color and pattern of the semi-transparent member by the semi-transparent member arranged on the viewer side of the display panel reflecting a portion of external light. According to the inventors' research, when an air layer is interposed between the semi-transparent member and the display panel, a portion of the external light that passes through the semi-transparent member is reflected at the air interface. The interfacially reflected light reflects the color of the incident light almost unchanged, and therefore includes the complementary color of the color of the semi-transparent member and the complementary color of the pattern. Therefore, when the light reflected by the semi-transparent member and the interfacially reflected light mix, the color of the semi-transparent member appears whitish and may not appear vivid.

[0008] Conventionally, for example, in Patent Document 1, contrast has been improved by placing a smoked panel 23 on the back side of a screen 20 (see FIG. 2). However, the smoked panel also absorbs transmitted light emitted from the display panel side toward the viewer side, which can reduce brightness during transmissive display. In order to increase the brightness of transmissive display, it is necessary to increase the brightness of the backlight, etc., which poses problems such as increased power consumption and heat generation.

[0009] Furthermore, according to the inventors' investigations, the phenomenon of the reflective display appearing whitish is not particularly problematic in semi-transparent members having a silver-toned reflective surface in which the wavelength of reflected light is almost constant in the visible light range, but there is room for improvement when using colored semi-transparent members that reflect light of specific wavelengths. Therefore, there is room for further investigation in order to achieve both a vivid reflective display and a highly bright transmissive display in display devices and optical films that include colored semi-transparent members.

[0010] The present invention has been made in view of the above-mentioned current situation, and has as its object to provide a display device and an optical film that can provide a vivid reflective display without reducing brightness. [Means for solving the problem]

[0011] (1) One embodiment of the present invention is a display device comprising an optical film and a display panel arranged on a rear side of the optical film, wherein the optical film is an integrated unit of a colored semi-transparent member and a first linear polarizer or a louver film having patterned light-absorbing portions and light-transmitting portions arranged on the rear side of the colored semi-transparent member, and the semi-transparent member transmits a portion of light incident from the rear side and reflects a portion of light incident from an observer side opposite to the rear side.

[0012] (2) Furthermore, in one embodiment of the present invention, in addition to the configuration of (1), the display panel includes a second linear polarizer on the viewer side, and the transmission axis of the first linear polarizer and the transmission axis of the second linear polarizer are parallel to each other.

[0013] (3) In addition to the configuration of (1) or (2), another embodiment of the present invention is a display device, wherein the first linear polarizer is an absorptive linear polarizer.

[0014] (4) Furthermore, in addition to the configuration of (1), another embodiment of the present invention is a display device in which the louver film has the light absorbing portions and the light transmitting portions arranged alternately in a plan view.

[0015] (5) Furthermore, in one embodiment of the present invention, in addition to the configuration of any one of (1) to (4) above, the semi-transparent member has a transmittance of 50% or more for light incident from the rear side.

[0016] (6) Furthermore, in addition to the configuration of any one of (1) to (5), another embodiment of the present invention is a display device, wherein the semi-transparent member contains a pigment that reflects light.

[0017] (7) Furthermore, in one embodiment of the present invention, in addition to the configuration of any one of (1) to (6) above, the optical film further comprises a first λ / 4 wavelength plate on the back side of the first linear polarizer.

[0018] (8) Furthermore, in addition to the configuration of (7), one embodiment of the present invention is a display device, wherein the transmission axis of the first linear polarizer and the slow axis of the first λ / 4 wavelength plate form an angle of substantially 45°.

[0019] (9) Furthermore, in one embodiment of the present invention, in addition to the configuration of (7) or (8) above, the display panel includes, in order from the viewer side, a second λ / 4 wavelength plate and a second linear polarizer, the transmission axis of the second linear polarizer and the slow axis of the second λ / 4 wavelength plate form an angle of substantially 45°, and the slow axis of the first λ / 4 wavelength plate and the slow axis of the second λ / 4 wavelength plate are orthogonal to each other.

[0020] (10) Furthermore, in one embodiment of the present invention, in addition to the configuration of any one of (1) to (9) above, the first linear polarizer is a coated polarizing layer containing dichroic molecules, and the coated polarizing layer containing dichroic molecules is formed on the semi-transparent member.

[0021] (11) Furthermore, in addition to the configuration of any one of (1) to (9), one embodiment of the present invention is a display device, wherein the first linear polarizer is a linear polarizer including a polarizing film containing dichroic molecules and a pair of protective films sandwiching the polarizing film containing the dichroic molecules.

[0022] (12) In addition to the configuration (11), in one embodiment of the present invention, the optical film further includes a transparent film on a surface opposite to the surface on which the first linear polarizer is disposed, and the difference between the linear expansion coefficient of the transparent film and the linear expansion coefficient of one of the protective films is 30×10 -6 / K or less display device.

[0023] (13) Furthermore, in one embodiment of the present invention, in addition to the configuration of any one of (1) to (9) above, the optical film is a display device comprising the semi-transparent member, the louver film, and a linear polarizer in this order.

[0024] (14) Furthermore, in one embodiment of the present invention, in addition to the configuration of any one of (1) to (13) above, the optical film further comprises an antireflection layer on the back side of the first linear polarizer or the louver film.

[0025] (15) Furthermore, in one embodiment of the present invention, in addition to the configuration of any one of (1) to (14) above, the display panel has, in a planar view, a display area and a frame area arranged around the display area, and has a light-shielding member arranged in an area that overlaps the frame area in a planar view.

[0026] (16) Another embodiment of the present invention is an optical film in which a colored semi-transparent member is integrated with a first linear polarizer or a louver film having patterned light-absorbing portions and light-transmitting portions, which is arranged on the back side of the semi-transparent member, and the semi-transparent member transmits a portion of light incident from the back side and reflects a portion of light incident from the observer side.

[0027] (17) Furthermore, in one embodiment of the present invention, in addition to the configuration (16), the first linear polarizer is an absorptive linear polarizer.

[0028] (18) Furthermore, in one embodiment of the present invention, in addition to the configuration of (16), the louver film is an optical film in which the light-absorbing portions and the light-transmitting portions are alternately arranged in a plan view.

[0029] (19) Furthermore, in one embodiment of the present invention, in addition to the configuration of any one of (16) to (18), the semi-transparent member is an optical film having a transmittance of 50% or more for light incident from the back side.

[0030] (20) In addition to the configuration of any one of (16) to (19), an embodiment of the present invention is such that the semi-transparent member is an optical film containing a pigment that reflects light.

[0031] (21) Furthermore, in one embodiment of the present invention, in addition to the configuration of any one of the above (16) to (20), the optical film further comprises a first λ / 4 wave plate on the back surface side of the first linear polarizer.

[0032] (22) Furthermore, in addition to the configuration of (21), an embodiment of the present invention is an optical film, wherein the transmission axis of the first linear polarizer and the slow axis of the first λ / 4 wavelength plate form an angle of substantially 45°.

[0033] (23) Furthermore, in one embodiment of the present invention, in addition to any one of the configurations (16) to (22) above, the first linear polarizer is a coated polarizing layer containing dichroic molecules, and the coated polarizing layer containing dichroic molecules is an optical film formed on the semi-transparent member.

[0034] (24) Furthermore, in addition to the configuration of any one of (16) to (22), an embodiment of the present invention is an optical film, wherein the first linear polarizer is a linear polarizer including a polarizing film containing dichroic molecules and a pair of protective films sandwiching the polarizing film containing dichroic molecules.

[0035] (25) In addition to the configuration (24), an embodiment of the present invention further comprises a transparent film on a surface opposite to the surface on which the first linear polarizer is disposed, and the difference between the linear expansion coefficient of the transparent film and the linear expansion coefficient of one of the protective films is 30×10 -6 Optical film with a temperature of 0.1 / K or less.

[0036] (26) Furthermore, in addition to the configuration of any one of (16) to (22), an embodiment of the present invention is an optical film comprising the semi-transparent member, the louver film, and a linear polarizer, in this order.

[0037] (27) In addition, in one embodiment of the present invention, in addition to the configuration of any one of the above (16) to (26), the optical film further comprises an antireflection layer on the back surface side of the first linear polarizer. [Effects of the Invention]

[0038] According to the present invention, it is possible to provide a display device and an optical film that can perform a vivid reflective display without reducing brightness. [Brief explanation of the drawings]

[0039] [Figure 1] 1 is a plan view schematically illustrating an example of a display device according to Embodiment 1. FIG. [Figure 2] FIG. 2 is a cross-sectional view taken along line X1-X2 in FIG. [Figure 3A] FIG. 2 is an explanatory diagram of a transmissive display of the display device according to the first embodiment. [Figure 3B] FIG. 2 is an explanatory diagram of a reflective display of the display device according to the first embodiment. [Figure 4A] FIG. 10 is an explanatory diagram of a transmissive display of a display device according to a first comparative example. [Figure 4B] FIG. 10 is an explanatory diagram of a reflective display of a display device according to a first comparative example. [Figure 5A] FIG. 10 is an explanatory diagram of a transmissive display of a display device according to a second comparative example. [Figure 5B] FIG. 10 is an explanatory diagram of a reflective display of a display device according to Comparative Example 2. [Figure 6] 10 is a cross-sectional view showing an example of a display device according to a second embodiment. FIG. [Figure 7A] FIG. 10 is an explanatory diagram of a transmissive display of a display device according to a second embodiment. [Figure 7B] FIG. 10 is an explanatory diagram of a reflective display of the display device according to the second embodiment. [Figure 8]FIG. 10 is a cross-sectional view showing an example of a display device according to a third embodiment. [Figure 9A] FIG. 10 is an explanatory diagram of a transmissive display of a display device according to a third embodiment. [Figure 9B] FIG. 10 is an explanatory diagram of a reflective display of a display device according to a third embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing an example of a display device according to a fourth embodiment. [Figure 11] 10 is a cross-sectional view showing an example of a display device according to a fifth embodiment. FIG. [Figure 12] 10 is a cross-sectional view showing an example of a display device according to a sixth embodiment. FIG. [Figure 13] 13 is a cross-sectional view showing an example of a display device according to a seventh embodiment. FIG. [Figure 14] FIG. 1 is a perspective view showing an example of a louver film. [Figure 15] 13 is a cross-sectional view showing an example of a display device according to an eighth embodiment. FIG. [Figure 16] FIG. 13 is a cross-sectional view showing an example of an optical film according to embodiment 9. [Figure 17] FIG. 13 is a cross-sectional view showing another example of the optical film according to the ninth embodiment. [Figure 18] FIG. 2 is a cross-sectional view showing an example of an optical film according to a tenth embodiment. [Figure 19] FIG. 2 is a cross-sectional view showing an example of an optical film according to an eleventh embodiment. [Figure 20] FIG. 22 is a cross-sectional view showing an example of an optical film according to embodiment 12. [Figure 21] FIG. 22 is a cross-sectional view showing an example of an optical film according to embodiment 13. [Figure 22] FIG. 20 is a cross-sectional view showing an example of an optical film according to embodiment 14. DETAILED DESCRIPTION OF THE INVENTION

[0040] The present invention will be described in more detail below with reference to the drawings, showing embodiments, but the present invention is not limited to these embodiments. In the following description, the same reference numerals will be used in different drawings to designate the same parts or parts having similar functions, and repeated description will be omitted. The various aspects of the present invention may be combined as appropriate within the scope of the present invention.

[0041] In this specification, "two directions are orthogonal" means that the angle between the two directions is preferably within a range of 90°±3°, more preferably within a range of 90°±1°, and even more preferably within a range of 90°±0.5°. "Two directions are parallel" means that the angle between the two directions is preferably within a range of 0°±3°, more preferably within a range of 0°±1°, and even more preferably within a range of 0°±0.5°.

[0042] In this specification, the term "viewer side" refers to the side from which the viewer views the display device, and is also referred to as the "front side." The term "rear side" refers to the side opposite the viewer side.

[0043] <<Display device>> One embodiment of the present invention is a display device comprising an optical film and a display panel arranged on a back side of the optical film, wherein the optical film is an integrated unit of a colored semi-transparent member and a first linear polarizer or a louver film having patterned light-absorbing portions and light-transmitting portions arranged on the back side of the colored semi-transparent member, and the semi-transparent member transmits a portion of light incident from the back side and reflects a portion of light incident from an observer side opposite to the back side.

[0044] (Embodiment 1) Fig. 1 is a plan view schematically illustrating an example of a display device according to embodiment 1. Fig. 2 is a cross-sectional view schematically illustrating the display device according to embodiment 1 taken along line X1-X2 in Fig. 1. As shown in Fig. 2, a display device 1-A according to embodiment 1 includes an optical film 110A and a display panel disposed on the rear surface side of the optical film 110A. The optical film 110A is formed by integrating a colored semi-transparent member 111 with a first linear polarizer 112 disposed on the rear surface side of the colored semi-transparent member 111.

[0045] Conventionally, a smoke layer has been disposed on the rear side of an optical film to suppress interfacial reflection. The smoke layer is, for example, a layer with low transmittance formed by solid printing or the like on the surface of a transparent substrate, and an example of a smoke layer with a transmittance of 50% or less is used. The smoke layer absorbs a portion of incident light, and its absorption rate is generally constant regardless of the polarization state or incidence angle of the incident light. In this embodiment, a first linear polarizer is disposed on the rear side of a colored semi-transparent member instead of the smoke layer, thereby enabling a vivid reflective display. In the display device according to this embodiment, it is preferable that a smoke layer is not disposed in the area of ​​the optical film 110A that overlaps with the display area of ​​the display panel 100.

[0046] Furthermore, in the display device according to this embodiment, the display panel 100 preferably includes a second linear polarizer 51 on the viewer side, and the transmission axis of the first linear polarizer 112 is preferably parallel to the transmission axis of the second linear polarizer 51. With this configuration, brighter transmissive display can be achieved without reducing luminance.

[0047] This embodiment can effectively provide a vivid reflective display by applying it to a display device in which the optical film and the display panel are spaced apart in the thickness direction, i.e., a display device having an air gap between the optical film and the display panel, as shown in Fig. 2. For example, in a display device in which a transparent adhesive or the like is filled between the optical film and the display panel and there is no air gap, interfacial reflection between the optical film and the display panel is unlikely to occur, and therefore the problem of the reflective display appearing whitish is unlikely to occur.

[0048] <Optical film> 2, the optical film 110A is formed by integrating a colored semi-transparent member 111 and a first linear polarizer 112. The integration means that there is no air layer between the semi-transparent member 111 and the first linear polarizer 112, and the semi-transparent member 111 and the first linear polarizer 112 may be bonded together with an adhesive layer or the like, or another member such as a transparent substrate may be present between the semi-transparent member 111 and the first linear polarizer 112.

[0049] (semi-transparent material) The semi-transparent member transmits a portion of light incident from the rear side and reflects a portion of light incident from the front side (viewer side) opposite the rear side. The semi-transparent member is a colored semi-transparent member. Colored refers to a chromatic color and does not include achromatic colors such as white and black, or silver. The chromatic color does not have a constant transmittance in the visible light region (400 to 700 nm), for example, a color with a difference of 30% or more in transmittance between 400 and 700 nm.

[0050] As described above, when the semi-transparent member is a colored semi-transparent member rather than an achromatic or silver member, it is susceptible to the influence of the interfacial reflection that occurs between the optical film and the display panel. Therefore, by applying the configuration of this embodiment to a display device having a colored semi-transparent member, it is possible to effectively suppress the whitish appearance of the reflective display and achieve a vivid reflective display. The whitish appearance means that the reflective display approaches an achromatic color.

[0051] The semi-transparent member may have a transmittance of 50% or more for light incident from the rear side. If the transmittance of the semi-transparent member is less than 50%, the brightness of the display device may decrease, making it difficult to see the displayed image in a bright environment. The transmittance of the semi-transparent member is more preferably 70% or more. The upper limit of the transmittance of the semi-transparent member is, for example, 90%. Note that it is sufficient for the semi-transparent member to have a transmittance of 50% or more in the region overlapping with the display region of the display panel 100.

[0052] In this specification, transmittance refers to total light transmittance, and is measured by a method conforming to JIS K 7361-1. The total light transmittance can be measured, for example, using a turbidity meter such as "HazeMeter NDH2000" manufactured by Nippon Denshoku Industries Co., Ltd.

[0053] The semi-transparent member has a reflectance range of approximately 3% to 50% for light incident from the viewer side. If the reflectance is less than 3%, the color or pattern is barely visible and is therefore ineffective. Furthermore, if the reflectance is 50% or more, this means that the transmittance is less than 50%, which is not preferable as it may make it difficult to see the displayed image in a bright environment. Note that the transmittance is the visible light transmittance, and the reflectance is the visible light reflectance.

[0054] The semi-transparent member may be disposed over the entire optical film in a plan view, or may be disposed partially so as to express a specific pattern or the like. The specific pattern is not particularly limited, but examples thereof include a stylish geometric pattern, a wood grain pattern, a specific character string, a company logo, etc. During reflective display, the specific pattern is visually recognized by the viewer. The semi-transparent member may be at least partially chromatic, and the entire semi-transparent member may be colored, or may include a partial achromatic region.

[0055] Examples of the semi-transparent member include a metal thin film, a dielectric multilayer film, a film containing a light-reflecting pigment, and a printed layer printed with a light-reflecting pigment.

[0056] Examples of the metal thin film include those formed by metal vapor deposition, sputtering, or the like using metals such as aluminum, silver, titanium, and tungsten. Generally, metal thin films are achromatic, but they can be colored by laminating them with color pigments. Examples of metal thin films laminated with color pigments include color anodized aluminum. The thickness of the metal thin film is, for example, 30 nm to 100 nm. Color anodized aluminum is formed by, for example, electrolytically treating the surface of aluminum to form an oxide film, and then impregnating the oxide film with a coloring agent to color it.

[0057] Specifically, the "SHA" shown in Figure 1 RP For example, a thin aluminum film having a thickness of 100 nm is formed on the character portion of "," and a half mirror having fine holes so that the aperture ratio is 50% is produced, and the half mirror is not formed on the periphery of the character. The half mirror is the semi-transparent member. By using the colored anodized aluminum as the aluminum, a colored semi-transparent member can be obtained.

[0058] The film containing a light-reflecting pigment (hereinafter also referred to as a reflective pigment) may be, for example, a film in which a reflective pigment is mixed in a binder resin. The printed layer printed with the reflective pigment may be printed on the surface of the transparent substrate 113 by a printing method such as gravure printing, screen printing, or inkjet printing. When the characters "SHAPR" shown in FIG. 1 are to be visible to the viewer in a reflective display, the character portion and the surrounding portion may be printed with a reflective pigment of different colors. Alternatively, either the character portion or the surrounding portion may be printed with a reflective pigment, and the other may be printed with a normal pigment that is not a reflective pigment, or the layer may be a resin layer that does not contain a pigment and is not printed.

[0059] The reflective pigment reflects specific wavelengths of external light toward the viewer, allowing the viewer to see a specific color depending on the reflected wavelength. The specific wavelength is light in the visible light range (380 nm to 780 nm). The semi-transparent member may contain reflective pigments of multiple colors, and the desired color can be seen by the viewer by additively mixing the reflected light from the reflective pigments of multiple colors. When printing is performed with reflective pigments, gaps are formed between the pigments, allowing at least a portion of the light incident from the display panel to be transmitted toward the viewer, even without providing micropores in the printing substrate as described in Patent Documents 1 and 2.

[0060] Examples of the reflective pigment include metal pigments. The metal pigment may reflect light of a specific wavelength and absorb light of wavelengths other than the specific wavelength. Examples of the metal pigment include metal pieces coated with a pigment, and the pigment may be further coated with a polymer such as an acrylic resin. Examples of the metal pigment include "Friend Color (registered trademark)" manufactured by Toyo Aluminum K.K. Furthermore, pearl pigments that utilize light interference can also be used, and a representative example is "Effect Pigments" manufactured by Merck Ltd.

[0061] The metal pieces are preferably those that reflect visible light, and examples thereof include aluminum, nickel, titanium, stainless steel, and alloys thereof.

[0062] The pigment coating the metal flakes may be either an organic pigment or an inorganic pigment, but is preferably an organic pigment. Examples of the organic pigment include phthalocyanine, halogenated phthalocyanine, quinacridone, diketopyrrolopyrrole, isoindolinone, azomethine metal complex, indanthrone, perylene, perinone, anthraquinone, dioxazine, benzimidazolone, condensed azo, triphenylmethane, quinophthalone, and anthrapyrimidine. Examples of the inorganic pigment include titanium oxide, iron oxide, carbon black, and bismuth vanadate.

[0063] Other forms of the semi-transparent member include, for example, a screen having a plurality of fine holes, or a decorative film having a plurality of transparent portions, on which a specific pattern is formed, as described in Patent Documents 1 and 2 above.

[0064] (First Linear Polarizer) The first linear polarizer 112 is a linear polarizer that converts incident light into linearly polarized light and is a component that changes the polarization state and / or direction of the incident light. The first linear polarizer 112 is preferably an absorptive linear polarizer that absorbs light in a specific polarization direction and transmits light in a direction perpendicular to the specific polarization direction, since this can more effectively suppress interfacial reflection.

[0065] The first linear polarizer may be a linear polarizer including a polarizing film containing dichroic molecules and a pair of protective films sandwiching the polarizing film containing dichroic molecules. Examples of the first linear polarizer include "TEG1465DU" manufactured by Nitto Denko.

[0066] Examples of polarizing films containing the above dichroic molecules include polyvinyl alcohol (PVA) films that have been subjected to a dyeing treatment with iodine and a stretching treatment (for example, uniaxial stretching).

[0067] The protective film may be one that is commonly used in the field of linear polarizers, and examples thereof include cellulose-based resin films such as triacetyl cellulose (TAC), and resin films such as polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, polysulfone-based, polystyrene-based, polynorbornene-based, polyolefin-based, (meth)acrylic-based, and acetate-based films. The protective film is preferably a transparent film, and may have a transmittance of 90% or more, for example.

[0068] The first linear polarizer is a coating-type polarizing layer containing dichroic molecules, and the coating-type polarizing layer containing dichroic molecules may be formed on the semi-transparent member. Examples of the coating-type polarizing layer containing dichroic molecules include a coating of a composition containing a compound having lyotropic liquid crystal properties and dichroic dye molecules. Examples of the dichroic dye molecules include dichroic dye molecules having an azo group. Coating-type polarizing layers disclosed in Patent Documents 3 to 6 may also be used.

[0069] When a polarizer in which the above-mentioned polarizing film is sandwiched between protective films is used as the first linear polarizer, the optical film 110A may warp depending on the pressure applied when the first linear polarizer is attached to the transparent substrate 113 or the difference in linear expansion coefficient between the transparent substrate 113 and the protective films. By using a coating-type polarizing layer as the first linear polarizer, warping of the optical film 110A can be suppressed.

[0070] The coating-type polarizing layer containing the dichroic molecules may be directly coated on the surface of a semi-transparent member. In this case, the coating-type polarizing layer containing the dichroic molecules and the semi-transparent member are in contact with each other. Alternatively, an alignment film may be formed on the surface of the semi-transparent member, and the coating-type polarizing layer may be formed on the surface of the alignment film. As the alignment film, a film commonly used in the field of liquid crystal panels may be used.

[0071] (Other parts) 2, the optical film 110A may have a transparent substrate 113 on the viewer side of the semi-transparent member 111. Although not shown, the optical film 110A may have a transparent substrate 113 on the back side of the semi-transparent member 111.

[0072] The transparent substrate 113 is preferably a light-transmitting member, and may be used as the substrate of the semi-transmitting member 111. From the viewpoint of maintaining high brightness of the display device, the transparent substrate 113 preferably has high transmittance, for example, a transmittance of 90% or more. Furthermore, from the viewpoint of preventing the displayed image from becoming blurred, the transparent substrate 113 preferably has a haze of 10% or less. The haze is measured by a method conforming to JIS K 7136, and can be measured using, for example, a turbidity meter such as "HazeMeter NDH2000" manufactured by Nippon Denshoku Industries Co., Ltd.

[0073] For example, a glass plate, or a resin plate such as an acrylic or polycarbonate plate can be used as the transparent base material 113. The transparent base material 113 may have a flat surface or a curved surface.

[0074] As shown in FIG. 2, when the transparent substrate 113 is disposed on the viewer side of the semi-transparent member 111, scratches on the semi-transparent member 111 can be prevented. By disposing the transparent substrate 113 on the viewer side of the semi-transparent member 111, a sense of depth and glossiness is created, but depending on the pattern of the semi-transparent member 111, the sense of depth and glossiness may make the texture appear inferior. From the viewpoint of expressing the texture of the semi-transparent member 111 more vividly, it is preferable to dispose the transparent substrate 113 on the back side of the semi-transparent member 111. On the other hand, if the semi-transparent member 111 is disposed closer to the viewer than the transparent substrate 113, the semi-transparent member 111 is more susceptible to scratches. Therefore, a hard coat layer (not shown) may be further provided on the viewer side of the semi-transparent member 111.

[0075] The hard coat layer preferably has high transparency and scratch resistance, and examples thereof include a coating layer made of an acrylic resin, an epoxy resin, etc. The hard coat layer preferably has a transmittance of 90% or more.

[0076] (display panel) As shown in FIG. 1, the display panel 100 may have, in a plan view, a display area and a frame area arranged around the display area. In FIG. 1, the dotted line indicates the boundary between the display area and the frame area of ​​the display panel, and the inner outer edge of the black matrix 23 shown in FIG. 2 forms the boundary between the display area and the frame area. The display area is an area including a plurality of pixels, and is an area where a desired image or the like is displayed during transmissive display. The frame area is an area that overlaps with the housing or bezel, and is not involved in transmissive display.

[0077] The display panel 100 preferably includes a second linear polarizer 51 on the viewer side. The second linear polarizer 51 may be the same as the first linear polarizer 112. The second linear polarizer 51 may be a linear polarizer including a polarizing film containing dichroic molecules and a pair of protective films that sandwich the polarizing film containing dichroic molecules.

[0078] The display panel 100 may be any panel that emits display light toward the viewer side and performs transmissive display, and may be a liquid crystal panel or a self-emitting panel such as an LED panel having light-emitting diodes (LEDs).

[0079] The following describes a case where a liquid crystal panel is used as the display panel 100. As shown in FIG. 2, the liquid crystal panel may have a second linear polarizer 51 on the viewer side and a third linear polarizer 52 on the back side. The second and third linear polarizers 51 and 52 are polarizers that transmit only light of a specific polarization direction. The linear polarizer may be an absorption-type linear polarizer that has a transmission axis that transmits only light of a specific polarization direction and an absorption axis that is perpendicular to the transmission axis. The second and third linear polarizers 51 and 52 are preferably arranged so that their transmission axes are perpendicular to each other.

[0080] The third linear polarizer 52 may be the same as the first linear polarizer 112. The second and third linear polarizers 51 and 52 may be known polarizers, such as "TEG1465DU" manufactured by Nitto Denko.

[0081] Although not shown, the second linear polarizer 51 may be attached to the surface of the TFT substrate 10 opposite the liquid crystal layer 30 using a transparent adhesive, and the third linear polarizer 52 may be attached to the surface of the CF substrate 20 opposite the liquid crystal layer 30 using a transparent adhesive.

[0082] The liquid crystal panel may include a first substrate, a second substrate, and a liquid crystal layer sandwiched between the first and second substrates. The first substrate may be a TFT substrate 10 having switching elements such as thin film transistors (TFTs), and the second substrate may be a color filter (CF) substrate 20 having color filters. The TFT substrate 10 and the CF substrate 20 are bonded together with a sealant 40, and a liquid crystal layer 30 is sealed between the two substrates.

[0083] Although not shown, the TFT substrate 10 may have a structure in which gate wiring and source wiring intersecting the gate wiring are provided on a support substrate, TFTs are disposed near the intersections of the gate wiring and source wiring, and pixel electrodes electrically connected to the TFTs are disposed. The area surrounded by the gate wiring and source wiring is a pixel.

[0084] The pixel electrode and the counter electrode described later may be transparent electrodes, and can be formed of a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), tin oxide (SnO), or an alloy thereof.

[0085] The color filter substrate 20 may have, for example, a color filter layer 22 and a black matrix 23 arranged on a support substrate 21. The color filter layer 22 may include red, green, and blue color filters. Each color filter is arranged to overlap with a pixel of the TFT substrate, and a desired color can be expressed by mixing the colors while controlling the amount of light transmitted through each color filter.

[0086] The black matrix 23 may be disposed so as to separate the color filters in a plan view. The color filters and the black matrix are not particularly limited, and any known materials in the field of liquid crystal panels can be used.

[0087] The support substrate used for the TFT substrate 10 and the CF substrate 20 is preferably a transparent substrate, and examples thereof include a glass substrate and a plastic substrate.

[0088] The display mode of the liquid crystal panel may be either a vertical electric field mode or a horizontal electric field mode. The vertical electric field mode includes a vertical alignment (VA) mode in which liquid crystal molecules in the liquid crystal layer are aligned substantially perpendicular to the substrate surface when no voltage is applied. The horizontal electric field mode includes a fringe field switching (FFS) mode or an in-plane switching (IPS) mode in which liquid crystal molecules in the liquid crystal layer are aligned substantially horizontal to the substrate surface when no voltage is applied. The no voltage application mode also includes a case in which a voltage less than the threshold value of the liquid crystal molecules is applied to the liquid crystal layer.

[0089] "Approximately horizontal" means that the tilt angle is 0° or more and 10° or less, preferably 0° or more and 5° or less, and more preferably 0° or more and 2° or less. "Approximately vertical" means that the tilt angle is 83° or more and 90° or less, preferably 85° or more and 90° or less, and more preferably 87.5° or more and 88.0° or less.

[0090] The liquid crystal layer 30 controls the amount of light transmission by changing the orientation of the liquid crystal molecules in response to an electric field generated in the liquid crystal layer 30 by a voltage applied between the pixel electrode and the counter electrode. In the vertical electric field method, the counter electrode is arranged on the TFT substrate side, and in the horizontal electric field method, the counter electrode is arranged on the CF substrate side.

[0091] The liquid crystal molecules may have a positive or negative dielectric anisotropy (Δε) defined by the following formula (L): Δε = (dielectric constant in the long axis direction) - (dielectric constant in the short axis direction) (L)

[0092] Although not shown, an alignment film for controlling the alignment direction of liquid crystal molecules when no voltage is applied may be disposed between the TFT substrate 10 and the liquid crystal layer 30, and between the CF substrate 20 and the liquid crystal layer 30. As the alignment film, a material commonly used in the field of liquid crystal panels, such as a polymer having polyimide, polyamic acid, polysiloxane, or the like in its main chain, can be used. (backlight) The display device according to the embodiment may further include a backlight on the rear side of the display panel 100. A known backlight 200 may be used, and may be, for example, an edge-light type in which light sources are arranged on the edge surface of a light guide plate, or a direct type in which multiple light sources are arranged within a plane and uniformity is improved using a diffuser or the like.

[0093] (Housing) The display device according to the embodiment may further include a housing 300 that houses the display panel 100 and the optical film 110A. Double-sided tape 301 may be placed on the back side of the optical film 110A that overlaps the frame region, and the optical film 110A may be fixed to the housing 300. A circuit board (not shown) on which a drive circuit for driving the display panel 100 and the backlight 200 is formed may be housed inside the housing 300. The housing 300 is not particularly limited as long as it can house the display panel 100 and the optical film 110A, and may be made of metal or resin. The shape of the housing 300 is also not limited to the shape shown in FIG. 2.

[0094] (Explanation of display method on the display device) 3A and 3B, a display method of the display device according to embodiment 1 will be described below. Fig. 3A is an explanatory diagram of transmissive display of the display device according to embodiment 1. Fig. 3B is an explanatory diagram of reflective display of the display device according to embodiment 1.

[0095] In Figures 3A and 3B, and Figures 4A, 4B, 5A, 5B, 7A, 7B, 9A, and 9B described below, unidirectional double-headed arrows and orthogonal double-headed arrows both represent the polarization state of light, with the unidirectional double-headed arrows representing linearly polarized light whose vibration direction is unidirectional, and the orthogonal double-headed arrows representing unpolarized light. In the above explanatory figures, the X2 direction in the cross-sectional view of the display device is defined as the 0° direction.

[0096] The display device 1-A according to the first embodiment is capable of performing reflective display and transmissive display. In this specification, reflective display refers to a display method in which light (external light) incident on the display device from the viewer side is reflected, allowing the viewer to view the color or pattern of a colored semi-transparent member. In this specification, transmissive display refers to a display method in which light (display light) emitted from the display panel side passes through the front plate and is emitted to the viewer side, allowing the viewer to view any image or the like displayed on the display panel.

[0097] As shown in FIG. 3A, in transmissive display, light (display light) L1 emitted from the viewer side of the display panel 100 passes through the second linear polarizer 51 disposed on the viewer side of the display panel 100 and becomes linearly polarized light L2. The linearly polarized light passes through the first linear polarizer 112, the semi-transparent member 111, and the transparent substrate 113 and is emitted toward the viewer side. Because the transmission axis of the first linear polarizer 112 and the transmission axis of the second linear polarizer 51 are parallel, the light transmitted through the second linear polarizer 51 is hardly absorbed by the first linear polarizer 112, and the light L3 emitted toward the viewer side is approximately L2 × 100%. Note that the transmittance of the semi-transparent member 111 is not taken into consideration, and it is assumed that there is no optical element between the first linear polarizer 112 and the second linear polarizer 51 that has a phase difference that changes the polarization state of the light. Although external light reflection, which will be described later, occurs even in transmissive display, when the amount of light emitted from the display panel 100 side is sufficiently greater than the external light, the observer finds it difficult to see the color, pattern, etc. of the semi-transparent member 111, and can see any image, etc. displayed on the display panel 100.

[0098] Next, reflective display will be described. As shown in FIG. 3B, if light incident on the display device from the viewer side is external light L4, a portion of L4 passes through the transparent substrate 113, is reflected by the semi-transparent member 111, and is emitted toward the viewer side (L5). Another portion of L4 passes through the semi-transparent member 111 and the first linear polarizer 112, is incident on the display panel 100 (including the second linear polarizer 51), and is absorbed by a color filter or the like inside the display panel 100 (L6). Furthermore, a portion of the light that passes through the optical film 110A (the transparent substrate 113, the semi-transparent member 111, and the first linear polarizer 112) is reflected at the interface with the air layer present between the optical film 110A and the display panel 100, and is emitted toward the viewer side (L7). If the interface reflectance at the interface between the optical film 110A and the air layer is α%, the proportion of light L7 that is emitted toward the viewer side out of the interface reflected light is approximately α% × 50% because it is transmitted through the first linear polarizer 112. There is also light reflected by the surface of the transparent substrate 113, and internally reflected light that is internally reflected by components such as wiring and electrodes that constitute the display panel 100 and is emitted again toward the viewer side, but a description of this will be omitted here.

[0099] The transmittance of the semi-transparent member 111 varies depending on the pattern formed on the semi-transparent member 111, but is, for example, about 60 to 80%. The transmittance of the semi-transparent member 111 can be measured using, for example, a spectrophotometer CM-5 manufactured by Konica Minolta.

[0100] As described above, the display device 1-A does not have a smoke layer, and the first linear polarizer 112 is integrated on the rear side of the semi-transmissive member 111. When the transmission axis of the first linear polarizer 112 is parallel to the transmission axis of the second linear polarizer 51 on the display panel 100 side, high brightness can be obtained more effectively in transmissive display. Furthermore, approximately 50% of the external light reflected at the interface between the optical film 110A and the air layer is absorbed by the first linear polarizer 112. In this way, the display device 1-A can achieve both bright transmissive display and vivid reflective display.

[0101] (Comparative form 1) A display method of the display device 1001 according to Comparative Example 1 will be described below with reference to Fig. 4A and Fig. 4B. Fig. 4A is an explanatory diagram of transmissive display of the display device according to Comparative Example 1. Fig. 4B is an explanatory diagram of reflective display of the display device according to Comparative Example 1. The display device 1001 according to Comparative Example 1 has the same configuration as the display device 1-A, except that the optical film 1110A does not have a polarizer (first linear polarizer 112).

[0102] 4A, in transmissive display, light (display light) L1 emitted from the viewer side of the display panel 100 passes through the second linear polarizer 51 to become linearly polarized light L2, which then passes through the semi-transparent member 111 and the transparent substrate 113 and is emitted to the viewer side. If the transmittance of the semi-transparent member 111 is not taken into consideration and the optical film 1110A does not have an optical element with a phase difference that changes the polarization state of light, then the light L3 emitted to the viewer side is approximately L2 × 100%.

[0103] Next, reflective display will be described. Light L5 reflected by the semi-transparent member 111 is the same as in the display device 1-A, and therefore will not be described here. Light L6, which is part of the external light L4 and is absorbed by components inside the display panel 100, will also not be described here. As shown in FIG. 4B , part of the external light L4 that passes through the optical film 1110A (the transparent substrate 113 and the semi-transparent member 111) is reflected at the interface by the air layer between the optical film 1110A and the display panel 100, and is emitted toward the viewer (L7). In the display device 1001 according to Comparative Example 1, the optical film 1110A does not have a polarizer, so the interface-reflected light is not absorbed, and the proportion of light L7 that is emitted toward the viewer among the interface-reflected light is approximately the interface reflectance α%×100%.

[0104] The brightness of the transmissive display of the display device 1-A according to the first embodiment and the display device 1001 according to the first comparative embodiment, and the proportion of the light reflected at the interface that is emitted to the viewer side, are shown in Table 1 below.

[0105] [Table 1]

[0106] As shown in Table 1, the display device 1001 of Comparative Form 1, in which the optical film does not have a polarizer, can achieve brightness in transmissive display that is equivalent to that of the display device 1-A of Embodiment 1. On the other hand, in reflective display, the display device 1001 of Comparative Form 1 has a higher proportion of interfacially reflected light that is emitted toward the viewer than the display device 1-A, and therefore the color and pattern of the semi-transparent member 111 appear whitish and not clear.

[0107] (Comparative form 2) 5A and 5B, a display method of the display device 1002 according to Comparative Form 2 will be described below. FIG. 5A is an explanatory diagram of a transmissive display of the display device according to Comparative Form 2. FIG. 5B is an explanatory diagram of a reflective display of the display device according to Comparative Form 2. The display device 1002 according to Comparative Form 2 has the same configuration as the display device 1-A according to Embodiment 1, except that the optical film 1110B has a smoke layer 400 on the back side of the semi-transparent member 111 instead of a polarizer.

[0108] The smoke layer 400 can be formed by applying a resin composition made by mixing a black pigment with a transparent resin to the back side of the front panel. The transmittance β of the smoke layer 400 can be adjusted by the amount of black pigment added, and is, for example, 70% or less.

[0109] 5A, in transmissive display, light (display light) L1 emitted from the viewer side of the display panel 100 passes through the smoke layer 400, the semi-transparent member 111, and the transparent substrate 113, and is emitted to the viewer side. If the transmittance of the semi-transparent member 111 is not taken into consideration, the optical film 1110B does not have an optical element with a phase difference that changes the polarization state of light, and the transmittance of the smoke layer 400 is β%, the luminance of light L3 emitted to the viewer side is approximately L2 × β%.

[0110] Next, reflective display will be described. Light L5 reflected by the semi-transparent member 111 is the same as in the display device 1-A, and therefore will not be described here. Light L6, which is part of the external light L4 and is absorbed by components inside the display panel 100, will also not be described here. As shown in FIG. 5B , part of the external light L4 that passes through the optical film 1110B (transparent substrate 113, semi-transparent member 111, and smoke layer 400) is reflected at the interface by the air layer between the optical film 1110B and the display panel 100, and is emitted toward the viewer (L7). In the display device 1002 according to Comparative Example 2, part of the interface-reflected light is absorbed by the smoke layer 400, and therefore the proportion of L7 that is emitted toward the viewer is approximately the interface reflectance α%×β%.

[0111] The brightness of the transmissive display of the display device 1-A according to embodiment 1, the display device 1001 according to comparative embodiment 1, and the display device 1002 according to comparative embodiment 2, as well as the proportion of the interfacially reflected light that is emitted toward the observer, are shown in Table 2 below.

[0112] [Table 2]

[0113] As shown in Table 2, the display device 1002 of Comparative Form 2, in which the optical film has a smoke layer instead of a polarizer, has lower brightness than the display device 1-A in transmissive display. On the other hand, in reflective display, the display device 1002 of Comparative Form 2 has a lower proportion of interfacial reflected light emitted toward the viewer than the display device 1001 of Comparative Form 1, and therefore provides a clearer reflective display than Comparative Form 1.

[0114] (Embodiment 2) 6 is a cross-sectional schematic diagram showing an example of a display device according to embodiment 2. As shown in FIG. 6, in a display device 1-B according to embodiment 2, an optical film 110B further includes a first λ / 4 wavelength plate 114 on the surface (back side) opposite to the surface on which the semi-transparent member 111 is disposed of the first linear polarizer 112. In the display device 1-B, by laminating the first linear polarizer 112 and the first λ / 4 wavelength plate 114, the display device can function as a circular polarizer and can convert incident light into circularly polarized light. Since the display device has the same configuration as embodiment 1 except that the optical film includes the first λ / 4 wavelength plate, a description of the overlapping configuration will be omitted.

[0115] The first λ / 4 wave plate is not particularly limited as long as it imparts a ¼ phase difference to incident light of wavelength λ. The first λ / 4 wave plate refers to a retardation plate that imparts an in-plane retardation of ¼ wavelength (strictly speaking, 137.5 nm) to light of wavelength 550 nm, for example, and preferably imparts an in-plane retardation of 120 nm or more and 150 nm or less.

[0116] The first λ / 4 wave plate may have a fast axis and a slow axis perpendicular to the fast axis, and the transmission axis of the first linear polarizer and the slow axis of the first λ / 4 wave plate may form an angle of substantially 45°. In this specification, "substantially 45°" preferably means within the range of 45°±3°, more preferably within the range of 45°±1°, and even more preferably within the range of 45°±0.5°.

[0117] 7A and 7B, a display method of the display device 1-B according to embodiment 2 will be described below. Fig. 7A is an explanatory diagram of transmissive display of the display device according to embodiment 2. Fig. 7B is an explanatory diagram of reflective display of the display device according to embodiment 2.

[0118] 7A , in transmissive display, light (display light) L1 emitted from the viewer side of the display panel 100 passes through the second linear polarizer 51 to become linearly polarized light L2, passes through the first λ / 4 waveplate 114 to become circularly polarized light, passes through the first linear polarizer 112 to become linearly polarized light, passes through the semi-transparent member 111 and the transparent substrate 113, and is emitted toward the viewer side (L3). At this time, approximately 50% of the circularly polarized light transmitted through the first λ / 4 waveplate 114 is absorbed by the first linear polarizer 112. If the transmittance of the semi-transparent member 111 is not taken into consideration and the optical film 110B does not include any optical elements having a phase difference that changes the polarization state of light other than the first linear polarizer 112 and the first λ / 4 waveplate 114, the light L3 emitted toward the viewer side is approximately L2×50%.

[0119] Next, reflective display will be described. Light L5 reflected by the semi-transmissive member 111 is the same as in the display device 1-A, and therefore will not be described here. Light L6, which is part of the external light L4 and is absorbed by components inside the display panel 100, will also not be described. As shown in FIG. 7B , part of the external light L4 that passes through the optical film 110B (transparent substrate 113, semi-transmissive member 111, first linear polarizer 112, and first λ / 4 wavelength plate 114) is reflected at the interface by the air layer between the optical film 110B and the display panel 100. The interface-reflected light again enters the first λ / 4 wavelength plate 114, becomes linearly polarized light with its polarization axis rotated by 90°, and enters the first linear polarizer 112, where it is mostly absorbed. Therefore, in the display device 1-B, interface-reflected light L7 is not emitted toward the viewer.

[0120] Table 3 below shows the luminance of the transmissive display of the display device 1-A and the display device 1-B according to the first embodiment, and the proportion of the interface-reflected light that is emitted to the viewer side.

[0121] [Table 3]

[0122] As shown in Table 3, display device 1-B, in which the optical film further includes a λ / 4 wavelength plate on the back side of the first linear polarizer, has a lower brightness in transmissive display than display device 1-A, but can achieve a very clear reflective display because the interfacial reflected light does not exit toward the viewer during reflective display.

[0123] (Embodiment 3) 8 is a cross-sectional view showing an example of a display device according to embodiment 3. As shown in FIG. 8, in a display device 1-C according to embodiment 3, a display panel 100 , Watch The display device 1-C includes, in order from the viewer side, a second λ / 4 wave plate 53 and a second linear polarizer 51. Second λ / 4 wave plate 53 Since the configuration is the same as that of the second embodiment except for including the above, a description of the overlapping configuration will be omitted. It is preferable that the transmission axis of the second linear polarizer 51 and the slow axis of the second λ / 4 wave plate 53 form an angle of substantially 45°, and that the slow axis of the first λ / 4 wave plate 114 and the slow axis of the second λ / 4 wave plate 53 are perpendicular to each other.

[0124] 9A and 9B, a display method of the display device 1-C according to embodiment 3 will be described below. Fig. 9A is an explanatory diagram of transmissive display of the display device according to embodiment 3. Fig. 9B is an explanatory diagram of reflective display of the display device according to embodiment 3.

[0125] As shown in FIG. 9A, in the transmissive display mode, light (display light) L1 emitted from the viewer side of the display panel 100 is polarized by the second linear polarizer 51 and the two The light passes through the first λ / 4 wave plate 114 to become circularly polarized light L2, then passes through the first linear polarizer 112, the semi-transparent member 111, and the transparent substrate 113, and is emitted to the viewer side (L3). At this time, the linearly polarized light that has passed through the first λ / 4 wave plate 114 is transmitted through the first linear polarizer 112 at almost 100%. If the transmittance of the semi-transparent member 111 is not taken into consideration and the optical film 110B does not include any optical elements having a phase difference that changes the polarization state of light other than the first linear polarizer 112 and the first λ / 4 wave plate 114, the light L3 emitted to the viewer side is approximately L2 × 100%.

[0126] Next, reflective display will be described. The light L5 reflected by the semi-transmissive member 111 is the same as that in the display device 1-A, and therefore will not be described here. The light L6 of the external light L4 that is absorbed by the internal members of the display panel 100 will also not be described. As shown in FIG. 9B, in the embodiment 2 Similarly, part of the external light L4 is transmitted through the optical film 110B and is reflected at the interface by the air layer between the optical film 110B and the display panel 100, and the polarization axis direction of the reflected light is rotated by 90° by the first λ / 4 wave plate 114, and the reflected light is mostly absorbed by the first linear polarizer 112. Therefore, in the display device 1-C, the interface-reflected light L7 is not emitted toward the viewer.

[0127] Table 4 below shows the luminance of the transmissive display of the display device 1-A according to the first embodiment and the display device 1-C according to the third embodiment, and the proportion of the interfacially reflected light that is emitted to the viewer side.

[0128] [Table 4]

[0129] As shown in Table 4, display device 1-C, in which the optical film further has a λ / 4 wavelength plate on the back side of the first linear polarizer and also has a λ / 4 wavelength plate on the observer side of the display panel, has a brightness in transmissive display that is as high as that of display device 1-A, and since interfacial reflected light does not exit toward the observer side during reflective display, it can achieve a very clear reflective display.

[0130] When the display panel has a circular polarizer (a combination of the first linear polarizer 112 and the first λ / 4 wavelength plate 114) on the viewer side, transmittance modulation can be performed effectively, and therefore, when the display panel is a liquid crystal panel, a vertical electric field type such as a VA mode is preferable to a horizontal electric field type such as an IPS mode as the display mode.

[0131] Furthermore, when the display panel has a circular polarizer (a combination of the first linear polarizer 112 and the first λ / 4 wavelength plate 114) on the viewer side, the internal reflectance of the display panel can be reduced, and therefore, when a self-luminous panel such as an OLED panel, which has a higher internal reflectance than a liquid crystal panel, is used as the display panel, a vivid reflective display can be more effectively achieved. This embodiment is particularly suitable for when a self-luminous panel is used in a bright environment such as outdoors.

[0132] The self-emitting panel is a panel that has a light-emitting element inside the panel and can emit light by itself, and can emit light toward the viewer without requiring an external light source such as a backlight. Known self-emitting panels can be used, and examples of such panels include OLED panels that include organic light-emitting diodes (OLEDs).

[0133] The configuration of the light-emitting diode is not particularly limited, and examples thereof include a cathode, a light-emitting layer, and an anode stacked in this order. When the light-emitting element is an OLED, the light-emitting layer may contain a fluorescent material, a phosphorescent material, or the like as a light-emitting material. An electron transport layer may be disposed between the cathode and the light-emitting layer, and a hole transport layer may be disposed between the light-emitting layer and the anode.

[0134] Light-emitting elements such as OLEDs may be arranged in a matrix on a TFT substrate. In this case, a light-emitting element may be arranged for each TFT (each pixel) arranged near the intersection of the gate wiring and the source wiring. The area where multiple light-emitting elements are arranged becomes the display area. The multiple light-emitting elements may include red light-emitting elements, green light-emitting elements, and blue light-emitting elements.

[0135] (Embodiment 4) Fig. 10 is a cross-sectional schematic diagram showing an example of a display device according to embodiment 4. As shown in Fig. 10, in display device 1-D according to embodiment 4, optical film 110C further includes an antireflection layer 115 on the surface (back side) opposite to the surface on which semi-transparent member 111 of first linear polarizer 112 is disposed. Since the optical film has the same configuration as embodiment 1 except for including the antireflection layer, a description of the overlapping configuration will be omitted. By including the antireflection layer in the optical film, it is possible to more effectively prevent light reflected at the interface in the air layer between the optical film and the display device from being emitted toward the viewer, thereby enabling a more vivid reflective display.

[0136] Examples of the antireflection layer include a resin layer containing a low refractive index material and a moth-eye film. The moth-eye film is a film that can suppress reflection by continuously changing the reflectance of incident light, and examples include a film in which minute irregularities on the order of nanometers are regularly arranged at intervals shorter than the wavelength of visible light on the surface of a transparent film. For example, Mosmite, manufactured by Mitsubishi Chemical Corporation, can be used as the antireflection layer.

[0137] (Embodiment 5) Fig. 11 is a cross-sectional view showing an example of a display device according to embodiment 5. As shown in Fig. 11, in display device 1-E according to embodiment 5, display panel 100 has, in a plan view, a display area and a frame area arranged around the display area, and has a light-shielding member 302 arranged in an area overlapping with the frame area in a plan view. Since the display panel has the same configuration as embodiment 1 except for the inclusion of the light-shielding member, a description of the overlapping configuration will be omitted.

[0138] Since the second linear polarizer 51 can perform transmissive display as long as it overlaps at least the display region of the display panel 100 in a planar view, the frame region that is not involved in transmissive display may include a region that does not overlap with the second linear polarizer 51 in a planar view. In the frame region, the region that does not overlap with the second linear polarizer 51 may be visible through the frame region during reflective display, or stray light may be generated by reflecting external light from the region. Therefore, by arranging the light-blocking member 302 in the region that overlaps with the frame region in a planar view, the region is prevented from being visible through the frame region and stray light is suppressed, thereby making the reflective display appear vivid. It is preferable that the light-blocking member 302 is not arranged in a region that overlaps with the display region in a planar view.

[0139] The material of the light blocking member 302 may be the same as that of the black matrix 23, or may be formed by printing black pigment or the like using a printing method such as screen printing. Also, black tape may be used.

[0140] (Embodiment 6) Fig. 12 is a cross-sectional schematic diagram showing an example of a display device according to embodiment 6. As shown in Fig. 12, in the display device 1-F according to embodiment 6, the first linear polarizer 112 is a linear polarizer including a polarizing film 112a containing dichroic molecules and a pair of protective films 112b that sandwich the polarizing film 112a containing dichroic molecules. Furthermore, as shown in Fig. 12, the optical film 110D further includes a transparent film 116 on the surface (viewer side) opposite to the surface on which the first linear polarizer 112 is disposed.

[0141] When a polarizer in which a polarizing film is sandwiched between protective films is used as the first linear polarizer, the optical film 110D may warp depending on the pressure applied when the first linear polarizer 112 is attached to the transparent substrate 113 or the difference in linear expansion coefficient between the transparent substrate 113 and the protective film 112b. In the sixth embodiment, warping of the optical film 110D can be suppressed by attaching a transparent film 116 having a linear expansion coefficient similar to that of the protective film 112b to the viewer side of the optical film 110D.

[0142] In the display device 1-F, the difference between the linear expansion coefficient of the transparent film 116 and the linear expansion coefficient of one of the protective films 112b is 30×10 -6 / K or less. With this configuration, warping of the optical film 110D can be effectively suppressed. The difference between the linear expansion coefficient of the transparent film 116 and the linear expansion coefficient of one of the protective films 112b is 50×10 -6 It is more preferable that the value is 0.1 / K or less.

[0143] The polarizing film 112a containing dichroic molecules and the protective film 112b may be the same as those in the first embodiment.

[0144] Examples of the transparent film 116 include the above-mentioned protective films, such as cellulose-based resin films such as triacetyl cellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, polysulfone-based, polystyrene-based, polynorbornene-based, polyolefin-based, (meth)acrylic-based, acetate-based, polyethylene terephthalate (PET), etc. It is preferable that the transparent film 116 has a transmittance of 90% or more.

[0145] In the sixth embodiment, the difference in linear expansion coefficient between the transparent film 116 and the protective film 112b is 30×10 -6 / K or less, and films of the same material or different materials may be used. For example, if protective film 112b is a TAC film, transparent film 116 may be a TAC film, a polyethylene terephthalate (PET) film, or the like.

[0146] The thickness of the transparent film 116 and the protective film 112b may be, for example, 50 μm to 200 μm. From the viewpoint of suppressing warping of the optical film 110D, it is preferable that the thickness of the transparent film 116 and the protective film 112b be equal, and the difference in thickness between the transparent film 116 and the protective film 112b is, for example, preferably 50 μm or less.

[0147] When the transparent substrate 113 and the protective film 112b of the first linear polarizer 112 are bonded together by an adhesive layer, and the transparent substrate 113 and the transparent film 116 are bonded together by another adhesive layer, from the viewpoint of suppressing warping of the optical film 110D, it is preferable that the thicknesses of the two adhesive layers are equal, and may be, for example, 5 μm to 50 μm.

[0148] (Embodiment 7) 13 is a cross-sectional view schematically illustrating an example of a display device according to embodiment 7. A display device 1-G according to embodiment 7 includes an optical film 110E and a display panel disposed on the rear side of the optical film 110E. The optical film 110E is formed by integrating a colored semi-transparent member 111 with a louver film 117 disposed on the rear side of the colored semi-transparent member 111. Since the configuration is the same as that of embodiment 1 except that the first linear polarizer is replaced with a louver film, a description of the overlapping configuration will be omitted.

[0149] The louver film is a component that absorbs light incident from a specific direction and is often used to prevent screen reflections on automobile windshields. It typically has the property of absorbing light incident from the vertical direction and transmitting other light. The louver film is often incorporated into backlights, and louver films used in the field of backlights may be used as the louver film of this embodiment. Using a louver film instead of a first linear polarizer can also achieve a vivid reflective display, and if applied to a display device that originally uses a louver film in the backlight, the brightness of the transmissive display will not change. Since the axis arrangement of a louver film does not need to be as strict as that of a linear polarizer, the design freedom of the display device can be increased.

[0150] The louver film has patterned light-absorbing portions and light-transmitting portions. Fig. 14 is a perspective view showing an example of a louver film. As shown in Fig. 14, an example of the patterned light-absorbing portions and light-transmitting portions may be light-transmitting portions 117a and light-absorbing portions 117b arranged alternately in a plan view. Examples of the louver film include N-VCF and W-VCF manufactured by Shin-Etsu Polymer Co., Ltd.

[0151] In a plan view, multiple light absorbing portions 117b may be arranged in parallel. The viewing angle characteristics can be adjusted by adjusting the spacing between the light absorbing portions 117b or the angle of the light absorbing portions 117b with respect to the normal direction of the optical film.

[0152] The light transmitting portion 117a may be made of a transparent resin, such as polystyrene resin, polyolefin resin, polyvinyl chloride resin, polyurethane resin, polyester resin, polyamide resin, urethane resin, fluorine resin, or silicone resin.

[0153] The light absorbing portion 117b may be a resin containing a colorant. Examples of the colorant include common organic or inorganic pigments such as carbon black, iron oxide, titanium oxide, yellow iron oxide, disazo yellow, and phthalocyanine blue. The resin used for the light absorbing portion 117b may be the same as the transparent resin used for the light transmitting portion 117a.

[0154] (Embodiment 8) Fig. 15 is a cross-sectional schematic diagram showing an example of a display device according to embodiment 8. As shown in Fig. 15, in a display device 1-H according to embodiment 8, an optical film 110F includes a semi-transparent member 111, a louver film 117, and a linear polarizer, in this order. With this configuration, a reflective display that is even more vivid than that of embodiment 7 can be realized, and if applied to a display device that originally uses a louver film for the backlight, the luminance of the transmissive display will not change.

[0155] In embodiment 8, the linear polarizer may be the first linear polarizer exemplified in embodiment 1, or may be a linear polarizer including a polarizing film containing dichroic molecules, a coating-type polarizing layer containing dichroic molecules, etc. The louver film may be one exemplified in embodiment 7.

[0156] The louver film typically controls the output direction without changing the polarization state of incident light, but may have some phase difference due to the resin in the light-transmitting portion, etc. Therefore, when laminating the first linear polarizer and the louver film, it is preferable to laminate them in the order of semi-transmitting member 111, louver film 117, and first linear polarizer 112, as shown in Fig. 15. It is preferable that the light transmission direction of louver film 117 and the transmission axis of first linear polarizer 112 are parallel to each other.

[0157] <<Optical Film>> In another embodiment of the present invention, a colored semi-transmitting member is integrated with a first linear polarizer or a louver film having patterned light-absorbing and light-transmitting portions arranged on the back side of the semi-transmitting member, and the semi-transmitting member is an optical film that transmits a portion of light incident from the back side and reflects a portion of light incident from the viewer side. The optical film can be used as a component of a display device. When used as a component of a display device, the colored semi-transmitting member may be arranged so as to be closer to the viewer than the first linear polarizer, and a display panel may be arranged on the back side of the first linear polarizer.

[0158] (Embodiment 9) Fig. 16 is a cross-sectional view schematically illustrating an example of an optical film according to embodiment 9. The optical film 110A according to embodiment 9 is similar to that described in the display device 1-A according to embodiment 1, and therefore a detailed description thereof will be omitted. As shown in Fig. 16, the optical film 110A includes a colored semi-transparent member 111 and a first linear polarizer 112 integrated together.

[0159] In this embodiment, instead of a smoke layer, a first linear polarizer is placed on the back side of the colored semi-transparent component of the optical film, thereby achieving a vivid reflective display and a bright transmissive display when a display panel is placed on the first linear polarizer side of the optical film.

[0160] The optical film 110A may have a transparent substrate 113 on the viewer side of the semi-transparent member 111, as shown in Fig. 16. Fig. 17 is a cross-sectional schematic view showing another example of the optical film according to embodiment 9. As shown in Fig. 17, the optical film 110A may have a transparent substrate 113 on the back side of the semi-transparent member 111.

[0161] The semi-transparent member is a colored semi-transparent member that transmits a portion of light incident from the rear surface side and reflects a portion of light incident from the viewer side opposite the rear surface. The semi-transparent member preferably has a transmittance of 50% or more, more preferably 70% or more, for light incident from the rear surface side. The upper limit of the transmittance of the semi-transparent member is, for example, 90%.

[0162] Examples of the semi-transparent member include a thin metal film, a film containing a light-reflecting pigment, and a printed layer printed with a light-reflecting pigment.

[0163] The first linear polarizer 112 is preferably an absorptive linear polarizer. The first linear polarizer may be a linear polarizer including a polarizing film containing the dichroic molecules described above and a pair of protective films sandwiching the polarizing film containing the dichroic molecules, or may be a coated polarizing layer containing dichroic molecules. The coated polarizing layer containing dichroic molecules may be formed on the semi-transparent member.

[0164] (Embodiment 10) Fig. 18 is a cross-sectional view schematically illustrating an example of an optical film according to embodiment 10. The optical film 110B according to embodiment 10 is similar to that described in the display device 1-B according to embodiment 2, and therefore a detailed description thereof will be omitted. As shown in Fig. 18, the optical film 110B further includes a first λ / 4 wave plate 114 on the surface of the first linear polarizer 112 opposite to the surface on which the semi-transmissive member 111 is disposed.

[0165] By laminating the first linear polarizer 112 and the first λ / 4 wave plate 114, it can function as a circular polarizer and convert incident light into circularly polarized light. Therefore, when a display panel is placed on the first linear polarizer side of the optical film, light reflected at the interface does not exit toward the viewer during reflective display, thereby realizing a very clear reflective display.

[0166] It is preferable that the transmission axis of the first linear polarizer and the slow axis of the first λ / 4 wave plate form an angle of substantially 45°.

[0167] (Embodiment 11) Fig. 19 is a cross-sectional view schematically illustrating an example of an optical film according to embodiment 11. The optical film 110C according to embodiment 11 is similar to that described in the display device 1-D according to embodiment 4, and therefore a detailed description thereof will be omitted. As shown in Fig. 19, the optical film 110C further includes an antireflection layer 115 on the surface of the first linear polarizer 112 opposite to the surface on which the semi-transmissive member 111 is disposed.

[0168] By providing the optical film with an anti-reflection layer, when a display panel is placed on the first linear polarizer side of the optical film, it is possible to more effectively prevent interfacial reflected light at the air layer between the optical film and the display device from being emitted toward the viewer.

[0169] (Embodiment 12) Fig. 20 is a cross-sectional schematic diagram showing an example of an optical film according to embodiment 12. The optical film 110D according to embodiment 12 is similar to that described in the display device 1-F according to embodiment 6, and therefore a detailed description thereof will be omitted. As shown in Fig. 20, in the optical film 110D, the first linear polarizer 112 is a linear polarizer including a polarizing film 112a containing dichroic molecules and a pair of protective films 112b sandwiching the polarizing film 112a containing dichroic molecules.

[0170] Furthermore, the optical film 110D further includes a transparent film 116 on the surface opposite to the surface on which the first linear polarizer 112 is disposed, and the difference between the linear expansion coefficient of the transparent film 116 and the linear expansion coefficient of one protective film 112b is 30×10 -6 / K or less. By attaching a transparent film 116 having a linear expansion coefficient similar to that of the protective film on the viewer side of the optical film 110D, warping of the optical film 110D can be suppressed.

[0171] (Embodiment 13) 21 is a cross-sectional view showing an example of an optical film according to embodiment 13. The optical film 110E according to embodiment 13 is similar to that described in the display device 1-G according to embodiment 7, and therefore a detailed description thereof will be omitted. The optical film 110E has a louver film 117 on the rear surface side of the semi-transparent member.

[0172] Using a louver film instead of the first linear polarizer also makes it possible to achieve both a bright transmissive display and a vivid reflective display when a display panel is disposed on the rear side of the optical film.

[0173] In louver film 117, light transmitting portions 117a and light absorbing portions 117b may be arranged alternately in a plan view.

[0174] (Embodiment 14) Fig. 22 is a cross-sectional view schematically illustrating an example of an optical film according to embodiment 14. The optical film 110F according to embodiment 14 is similar to that described in the display device 1-H according to embodiment 8, and therefore a detailed description thereof will be omitted. As shown in Fig. 22, the optical film 110F includes a semi-transparent member 111, a louver film 117, and a linear polarizer, in this order. The linear polarizer may be the first linear polarizer 112 described above.

[0175] Optical film 110F comprises semi-transparent member 111, louver film 117, and first linear polarizer 112 in this order, and when a display panel is placed on the first linear polarizer side of the optical film, it is possible to achieve both a bright transmissive display and an even more vivid reflective display.

[0176] The linear polarizer may be the same as the first linear polarizer exemplified in embodiment 1, or may be a linear polarizer including a polarizing film containing dichroic molecules, a coating-type polarizing layer containing dichroic molecules, or the like.

[0177] The display device and optical film according to the above embodiment may be used, for example, as an instrument panel of an automobile to display gauges such as a speedometer, or may be used as an operation panel of a home appliance. [Explanation of symbols]

[0178] 1-A, 1-B, 1-C, 1-D, 1-E, 1-F, 1-G, 1-H, 1001, 1002: Display device 10: First substrate (TFT substrate) 20: Second board (CF board) 21: Support substrate 22: Color filter layer 23: Black Matrix 30: Liquid crystal layer 31: Light-emitting layer 40: Sealing material 51: Second linear polarizer 52: Third linear polarizer 53: Second λ / 4 wave plate 100: Display panel 110A, 110B, 110C, 110D, 110E, 110F, 1110A, 1110B: Optical film 111: Semi-transparent material 112: First linear polarizer 112a: Polarizing film containing dichroic molecules 112b: Protective film 113: Transparent material 114: First λ / 4 wave plate 115: Anti-reflection layer 116:Transparent film 117: Louver film 117a: Light transmission part 117b: Light absorbing part 200: Backlight 300: Cabinet 301: Double-sided tape 302: Light blocking material 400: Smoke layer

Claims

1. an optical film; and a display panel disposed on a rear side of the optical film; the optical film is an integrated film comprising a colored semi-transparent member and a first linear polarizer or a louver film having patterned light-absorbing portions and light-transmitting portions, the first linear polarizer being disposed on the rear surface side of the colored semi-transparent member; the semi-transparent member transmits a portion of light incident from the rear side and reflects a portion of light incident from a viewer side opposite to the rear side; the display panel includes a second linear polarizer on the viewer side; a transmission axis of the first linear polarizer and a transmission axis of the second linear polarizer being parallel to each other;

2. 2. The display device according to claim 1, wherein the first linear polarizer is an absorptive linear polarizer.

3. 3. The display device according to claim 1, wherein the semi-transparent member has a transmittance of 50% or more for light incident from the rear surface side.

4. an optical film; and a display panel disposed on the rear side of the optical film; the optical film is an integrated film comprising a colored semi-transparent member and a first linear polarizer or a louver film having patterned light-absorbing portions and light-transmitting portions, the first linear polarizer being disposed on the rear surface side of the colored semi-transparent member; the semi-transparent member transmits a portion of light incident from the rear side and reflects a portion of light incident from a viewer side opposite to the rear side; The display device is characterized in that the semi-transparent member contains a pigment that reflects light.

5. an optical film; and a display panel disposed on the rear side of the optical film; The optical film includes a colored semi-transparent member and a first linear polarizer disposed on the rear surface side of the colored semi-transparent member, the first linear polarizer being integrated with the colored semi-transparent member; the semi-transparent member transmits a portion of light incident from the rear side and reflects a portion of light incident from a viewer side opposite to the rear side; The display device, wherein the optical film further comprises a first λ / 4 wave plate on the rear side of the first linear polarizer.

6. 6. The display device according to claim 5, wherein the transmission axis of the first linear polarizer and the slow axis of the first λ / 4 wave plate form an angle of substantially 45°.

7. the display panel includes, in order from the viewer side, a second λ / 4 wave plate and a second linear polarizer; 6. The display device according to claim 5, wherein the transmission axis of the second linear polarizer and the slow axis of the second λ / 4 wave plate form an angle of substantially 45°, and the slow axis of the first λ / 4 wave plate and the slow axis of the second λ / 4 wave plate are perpendicular to each other.

8. an optical film; and a display panel disposed on the rear side of the optical film; the optical film is an integrated product of a colored semi-transparent member and a louver film having patterned light-absorbing portions and light-transmitting portions, the louver film being disposed on the rear surface side of the colored semi-transparent member; the semi-transparent member transmits a portion of light incident from the rear side and reflects a portion of light incident from a viewer side opposite to the rear side; The display device is characterized in that the optical film comprises the semi-transparent member, the louver film, and a linear polarizer in this order.

9. an optical film; and a display panel disposed on the rear side of the optical film; the optical film is an integrated film comprising a colored semi-transparent member and a first linear polarizer or a louver film having patterned light-absorbing portions and light-transmitting portions, the first linear polarizer being disposed on the rear surface side of the colored semi-transparent member; the semi-transparent member transmits a portion of light incident from the rear side and reflects a portion of light incident from a viewer side opposite to the rear side; The display device is characterized in that the optical film further comprises an anti-reflection layer on the back side of the first linear polarizer or the louver film.

10. the first linear polarizer is a coating-type polarizing layer containing dichroic molecules, 10. The display device according to claim 1, wherein the coating-type polarizing layer containing the dichroic molecules is formed on the semi-transmissive member.

11. 10. The display device according to claim 1, 4, 5 or 9, characterized in that the first linear polarizer is a linear polarizer including a polarizing film containing dichroic molecules and a pair of protective films sandwiching the polarizing film containing the dichroic molecules.

12. the optical film further includes a transparent film on a surface opposite to the surface on which the first linear polarizer is disposed, The difference between the linear expansion coefficient of the transparent film and the linear expansion coefficient of one of the protective films is 30×10 －６ 12. The display device according to claim 11, wherein the value is equal to or less than 1 / K.

13. the display panel has, in a plan view, a display area and a frame area arranged around the display area; 10. The display device according to claim 1, further comprising a light-shielding member disposed in an area overlapping the frame area in a plan view.

14. a colored semi-transparent member and a first linear polarizer or a louver film having patterned light-absorbing portions and light-transmitting portions, which are arranged on the back surface side of the semi-transparent member, are integrated together; the semi-transparent member transmits a portion of light incident from the rear side and reflects a portion of light incident from a front side opposite to the rear side, The optical film is characterized in that the semi-transparent member contains a pigment that reflects light.

15. a colored semi-transparent member and a first linear polarizer disposed on the rear side of the semi-transparent member are integrated together; the semi-transparent member transmits a portion of light incident from the rear side and reflects a portion of light incident from a front side opposite to the rear side, An optical film further comprising a first λ / 4 wave plate on the back side of the first linear polarizer.

16. a colored semi-transparent member and a louver film having patterned light-absorbing portions and light-transmitting portions arranged on the rear surface side of the semi-transparent member are integrated together; the semi-transparent member transmits a portion of light incident from the rear side and reflects a portion of light incident from a front side opposite to the rear side, An optical film comprising the semi-transparent member, the louver film, and a linear polarizer in this order.

17. a colored semi-transparent member and a first linear polarizer or a louver film having patterned light-absorbing portions and light-transmitting portions, which are arranged on the back surface side of the semi-transparent member, are integrated together; the semi-transparent member transmits a portion of light incident from the rear side and reflects a portion of light incident from a front side opposite to the rear side, An optical film further comprising an antireflection layer on the back surface side of the first linear polarizer or the louver film.

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