JP2009145698A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device capable of obtaining desired display properties even in a high-temperature environment. <P>SOLUTION: The display device includes: a lens array unit 20 having a lens array layer 201; and a display unit 10 having a structure where an array substrate 11 is stuck to a counter substrate 12 disposed between the array substrate 11 and the lens array unit 20. The display device includes: a first light-transmissive conductive film 203 disposed close to the display unit 10 in the lens array unit 20; a second light-transmissive film 103 disposed close to the lens array unit 20 in the display unit 10; and a dielectric layer 400 disposed between the first conductive film 203 and the second conductive film 103. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a display device, and more particularly to a stereoscopic image display device including a lens array unit.

  Various methods are known for stereoscopic image display devices capable of displaying moving images, so-called three-dimensional displays. In recent years, there has been a growing demand for a flat panel type method that does not require special glasses. Of this type of stereoscopic video display device, the method using the principle of holography is difficult to realize a full-color video, but the pixel position is fixed as in a direct-view or projection-type liquid crystal display device or plasma display device. A method of installing a light beam control element that controls the light beam from the display unit and directs it to the observer just before the display unit (display device) can be realized relatively easily.

  The light beam control element is generally called a parallax barrier or a parallax barrier, and controls light beams so that different images can be seen depending on the angle even at the same position on the light beam control element. Specifically, slits or lenticular lens sheets (cylindrical lens arrays) are used when only left-right parallax (horizontal parallax) is given, and pinhole arrays or matrix shapes are used when vertical parallax is also included. A lens array consisting of these lenses is used. The system using the parallax barrier is further classified into a binocular system, a multi-view system, a super multi-view system (multi-view super multi-view condition), and an integral photography (hereinafter also referred to as IP). These basic principles are substantially the same as those invented about 100 years ago and used in stereoscopic photography.

  Among these, the IP method has a feature that the viewpoint position is highly flexible and stereoscopic viewing can be easily performed. As described in Non-Patent Document 1, the one-dimensional IP method with only horizontal parallax and no vertical parallax can relatively easily realize a display device with high resolution. On the other hand, the binocular method and the multi-view method have a problem that the range of viewpoint positions that can be viewed stereoscopically, that is, the viewing range is narrow and difficult to see, but the configuration as a stereoscopic image display device is the simplest, and the display image Can also be created easily.

In a lens array unit that is one of the light beam control elements, it is important to keep the distance between the lens and the pixel uniform in order to obtain a stereoscopic display characteristic. For example, Patent Document 1 discloses a configuration in which a microlens substrate is disposed on the front surface of a display panel.
SID04 Digest 1438 (2004) JP 2006-189844 A

  If the lens array unit is placed in close contact with the display unit to maintain a uniform distance between the lens and the pixel, the lens, polarizing plate, glass substrate, etc. will remain at a high temperature if left in a high temperature environment for a long time. If the coefficient of linear expansion of the lens, polarizing plate, glass substrate, etc. is different, the lens array unit or the display unit may be warped and separated. For this reason, the uniformity of the distance between the lens and the pixel is impaired, and desired display characteristics may not be obtained.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a display device capable of obtaining desired display characteristics regardless of the use environment.

A display device according to an aspect of the present invention includes:
A lens array unit having a lens array layer;
A display unit comprising a first substrate and a display unit having a structure in which a second substrate disposed between the first substrate and the lens array unit is bonded,
A light-transmissive first conductive film disposed on the display unit side of the lens array unit;
A second conductive film having optical transparency disposed on the lens array unit side of the display unit;
A dielectric layer disposed between the first conductive film and the second conductive film;
It is provided with.

  According to the present invention, it is possible to provide a display device capable of obtaining desired display characteristics regardless of the use environment.

  A display device according to an embodiment of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, the display device includes a display unit 10 and a lens array unit 20 that is a light beam control element. The display unit 10 has a structure in which a pair of substrates, that is, a first substrate 11 and a second substrate 12 are bonded together. The second substrate 12 is disposed between the first substrate 11 and the lens array unit 20.

  The display unit 10 includes a liquid crystal display panel, a plasma display panel, an organic electroluminescence (EL) display panel, a field emission display panel, and the like, and the type is not particularly limited. In this embodiment, an example in which a liquid crystal display panel is applied as the display unit 10 will be described.

  As shown in FIGS. 2 and 3, the liquid crystal display panel 10 has a structure in which a liquid crystal layer 13 is held between a pair of substrates, that is, an array substrate (first substrate) 11 and a counter substrate (second substrate) 12. Is displayed. This display area DA is composed of a plurality of pixels PX arranged in a matrix.

  The array substrate 11 is formed using a light-transmitting insulating substrate 11A such as a glass substrate. The array substrate 11 includes a wiring portion that supplies a drive signal to each pixel PX on the insulating substrate 11A. That is, the array substrate 11 has a plurality of scanning lines Y (Y1 to Ym) and a plurality of auxiliary capacitance lines C (C1 to Cm) arranged in the row direction of the pixels PX as a wiring portion, and the column direction of the pixels PX. A plurality of signal lines X (X1 to Xn) arranged along the switching line SW, switching elements SW arranged for each pixel PX, and the like. Furthermore, the array substrate 11 includes pixel electrodes PE connected to the respective switching elements SW. Each of the scanning lines Y is connected to a gate driver YD that supplies a driving signal (scanning signal). Each of the signal lines X is connected to a source driver XD that supplies a drive signal (video signal).

  Each switching element SW is composed of, for example, a thin film transistor. The switching element SW is disposed at the intersection of the scanning line Y and the signal line X corresponding to each pixel PX. The gate of the switching element SW is connected to the corresponding scanning line Y (or formed integrally with the scanning line Y). The source of the switching element SW is connected to the corresponding signal line X (or formed integrally with the signal line X). The drain of the switching element SW is electrically connected to the pixel electrode PE.

  Each pixel electrode PE is disposed on the insulating film IL covering the switching element SW, and is electrically connected to the drain of the switching element SW through a contact hole formed in the insulating film IL. In the transmissive liquid crystal display panel 10 that selectively transmits backlight light emitted from the backlight unit and displays an image, the pixel electrode PE is made of indium tin oxide (ITO) or indium zinc oxide. It is formed of a light-transmitting conductive material such as oxide (IZO). Each pixel electrode PE selectively reflects external light (including front light emitted from the front light unit) incident from the counter substrate 12 side to display an image in the reflective liquid crystal display panel 10. Is formed of a light-reflective conductive material such as aluminum (Al). The surface of such a pixel electrode PE is covered with a first alignment film AL1 for controlling the alignment of liquid crystal molecules contained in the liquid crystal layer 13.

  The counter substrate 12 is formed using a light-transmitting insulating substrate 12A such as a glass substrate. The counter substrate 12 includes a counter electrode CE disposed on the insulating substrate 12A so as to be opposed to the plurality of pixel electrodes PE. The counter electrode CE is formed of a light-transmitting conductive material such as ITO. The surface of the counter electrode CE is covered with a second alignment film AL2 for controlling the alignment of liquid crystal molecules included in the liquid crystal layer 13.

  The array substrate 11 and the counter substrate 12 are bonded together by a seal material (not shown) in a state where the pixel electrode PE and the counter electrode CE are opposed to each other. A spacer (not shown) is interposed between the array substrate 11 and the counter substrate 12, and a predetermined cell gap is formed between the substrates. The liquid crystal layer 13 is formed of a liquid crystal composition sealed in the cell gap between the array substrate 11 and the counter substrate 12. In this embodiment, the liquid crystal mode is not particularly limited, and a TN (Twisted Nematic) mode, an OCB (Optically Compensated Bend) mode, a VA (Vertical Aligned) mode, an IPS (In-Plane Switching) mode, and the like are applicable. is there.

  In the color display type liquid crystal display device, the liquid crystal display panel 10 includes a plurality of types of pixels PX, for example, a red pixel that displays red (R), a green pixel that displays green (G), and a blue that displays blue (B). Has pixels. That is, the red pixel includes a red color filter that transmits light having a red main wavelength. The green pixel includes a green color filter that transmits light having a green dominant wavelength. The blue pixel includes a blue color filter that transmits light having a blue main wavelength. These color filters are arranged on the main surface of the array substrate 11 or the counter substrate 12.

  Each pixel PX has a liquid crystal capacitor CLC between the pixel electrode PE and the counter electrode CE.

The plurality of auxiliary capacitance lines C (C1 to Cm) are capacitively coupled to the pixel electrodes PE in the corresponding rows, respectively, to form the auxiliary capacitance Cs.

  In the configuration to which the transmissive liquid crystal display panel 10 is applied, a first optical element OD1 including a backlight unit and including a polarizing plate is disposed on the outer surface of the array substrate 11 corresponding to the display area DA as shown in FIG. In addition, a second optical element OD2 including a polarizing plate is also disposed on the outer surface of the counter substrate 12 in the same manner.

  As shown in FIG. 1, the lens array unit 20 includes a base body 202 and a lens array layer 201 disposed on the base body 202.

  As shown in FIGS. 4A and 4B, the lens array layer 201 includes a plurality of cylindrical lenses arranged in one direction. Here, for the sake of convenience, the direction parallel to the direction in which the scanning lines extend is X, the direction parallel to the direction in which the signal lines extend is Y, and the normal direction of the XY plane (the thickness direction of the display unit 10). ) Is Z, in the example shown in FIG. 4A, each cylindrical lens has a shape in which the generatrix of the cylindrical surface extends in the Y direction, and a plurality of cylindrical lenses are arranged in the X direction. In the example shown in FIG. 4B, each cylindrical lens has a shape in which the generatrix of the cylindrical surface is inclined with respect to the Y direction, and a plurality of cylindrical lenses are arranged in the X direction.

  In the lens array layer 201, the horizontal pitch Ps of the cylindrical lenses is a pitch in a direction that coincides with the row direction (that is, the X direction) in the display area DA of the display unit 10. The lens array layer 201 is formed over at least a region facing the display area DA when the lens array unit 20 is disposed facing the display unit 10. That is, the area where the lens array layer 201 is formed is set to be equal to or greater than the display area DA.

  The thickness of the lens array layer 201 (that is, the thickness from the surface of the substrate to the top portion of the lens) is, for example, about 0.05 mm to 0.5 mm, and the digging amount between the lenses is, for example, 0.05 mm. These values are about 0.1 mm, but these values can be variously changed according to the design.

  The substrate 202 is a flat plate that supports the lens array layer 201 and preferably has a size larger than that of the lens array layer 201. The base body 202 has a thickness of about 0.7 mm to 1.1 mm, for example, but a thicker one having a thickness of about several mm may be applied as necessary.

  Such a lens array unit 20 is fixed to the display unit 10 with an adhesive 30. The adhesive 30 is disposed so as to surround the display area DA. As such an adhesive 30, a thermosetting resin material, an ultraviolet curable resin material, or the like can be used.

  In the example shown in FIG. 1, the lens array unit 20 is arranged so that the lens array layer 201 side faces the display unit 10 in close contact. Although it is possible to apply a structure in which the lens array layer 201 faces the observer side, when a thick substrate 202 is used to ensure durability and reliability, the lens focal length becomes long, so that the lens design is performed. If face glass is further installed on the outer side in order to prevent external light reflection due to the point of restriction or the convex surface of the lens, the number of members and the weight increase.

  Here, a configuration example of the lens array unit 20 and the display unit 10 will be described more specifically.

  The lens array unit 20 further includes a first conductive film 203 on the display unit 10 side. In the example shown in FIGS. 5 and 6, the first conductive film 203 is disposed on the surface of the lens array layer 201. Here, the first conductive film 203 is disposed on the entire surface of the cylindrical lens of the lens array layer 201. The first conductive film 203 is made of a light-transmitting conductive material, such as ITO or IZO.

  The display unit 10 further includes a second conductive film 103 on the lens array unit 20 side. That is, the second conductive film 103 is disposed between the counter substrate 12 and the lens array unit 20. In the example shown in FIGS. 5 and 6, the second conductive film 103 is disposed on the surface of the optical element OD <b> 2 (that is, the surface facing the lens array unit 20).

  As shown in FIG. 7, the optical element OD2 is configured by a laminate in which a polarizing layer 104B formed of polyvinyl alcohol (PVA) is sandwiched between base materials 104A formed of triacetate cellulose (TAC). The second conductive film 103 is disposed on the base material 104A of the optical element OD2. Here, the second conductive film 103 is disposed on the entire surface of the optical element OD2. The second conductive film 103 is formed of a light-transmitting conductive material, such as ITO or IZO. A hard coat layer may be disposed on the surface of the second conductive film 103.

  A dielectric layer 400 is disposed between the first conductive film 203 and the second conductive film 103. The dielectric layer 400 is provided in the lens array unit 20 or the display unit 10. In the example illustrated in FIG. 5, the dielectric layer 400 is provided in the display unit 10 and is disposed on the second conductive film 103. In the example shown in FIG. 6, the dielectric layer 400 is provided in the lens array unit 20 and is disposed on the first conductive film 203.

  Such a dielectric layer 400 has optical transparency and is formed of an insulating material regardless of an organic material or an inorganic material. In the case of the example shown in FIG. 5, the dielectric layer 400 may function as a hard coat layer, or a hard coat layer may be disposed separately from the dielectric layer 400. In the case of the example shown in FIG. 6, a hard coat layer may be disposed on the second conductive film 103 separately from the dielectric layer 400.

  The first conductive film 203 and the second conductive film 103 are connected to the voltage application unit 500.

  In such a configuration, when a voltage is applied between the first conductive film 203 and the second conductive film 103 by the voltage application unit 500, the first conductive film 203 side of the dielectric layer 400 and the second conductive film Polarization occurs on the 103 side. Accordingly, the first conductive film 203 and the second conductive film 103 are attracted by electrostatic force without short-circuiting, and the lens array unit 20 and the display unit 10 are in close contact with each other.

  For this reason, even if left in a high temperature environment, the lens array unit 20 and the display unit 10 are brought into contact with each other by an electrostatic force, so that they are kept in close contact with each other. Further, even if warpage occurs due to thermal expansion of the member, the lens array unit 20 and the display unit 10 are kept in close contact with each other.

  Therefore, according to this embodiment, the distance between the lens and the pixel PX can be kept uniform even in a high temperature environment, and desired display characteristics can be obtained.

  Various types of such lens array unit 20 have been proposed, and any of them can be applied.

  The lens array unit 20 in the example shown in FIG. 8A is integrally formed by a glass base 202 and a glass lens array layer 201. That is, in the example of FIG. 8A, the surface of the glass substrate is processed to directly form a lens shape, and the first conductive film 203 is formed thereon. Thus, the lens array unit 20 integrally formed of glass has an advantage that it is not easily affected by temperature changes and can maintain stable performance.

  The lens array unit 20 in the example shown in FIG. 8B is obtained by bonding a resin lens array layer 201 to a glass substrate 202 via an adhesive layer 204 and forming a first conductive film 203 thereon. . In the example shown in FIG. 8C, the lens array unit 20 is obtained by molding a resin lens array layer 201 directly on a glass base 202 and forming a first conductive film 203 thereon. The resin lens array layer 201 is made of a material such as PMMA (polymethyl methacrylate) or PC (polycarbonate).

  Such a resin lens array layer 201 has an advantage that it can be manufactured at low cost by press molding or injection molding. On the other hand, since the resin material has a larger linear expansion coefficient than the glass forming the base body 202, it is easily affected by temperature changes. For this reason, it is desirable that the lens array layer 201 is attached to a relatively thick substrate 202 for the purpose of controlling fluctuations in the horizontal pitch Ps.

  In the example shown in FIGS. 8A to 8C, a dielectric layer 400 may be further disposed on the first conductive film 203.

  Next, as an example of a display device, a display device capable of displaying a one-dimensional IP system or multi-view 3D video will be described.

  FIG. 9 is a perspective view schematically showing a configuration of a part of the stereoscopic video display apparatus.

  The stereoscopic image display apparatus includes a display unit 10 such as a liquid crystal display panel including an element image display unit, and a lens array unit 20 that functions as a light beam control element having an optical aperture. The lens array layer 201 of the lens array unit 20 is provided so as to face the element image display unit, and performs stereoscopic display with light beams in each direction with reference to each lens principal point of the lens array layer 201.

  Here, in particular, a case is shown in which a lens array unit (lenticular sheet) 20 formed of a cylindrical lens array is arranged on the front surface of a planar element image display unit such as a liquid crystal display panel. As shown in FIG. 9, in the element image display unit, sub-pixels 31 having an aspect ratio of 3: 1 are arranged in a matrix in a straight line in the horizontal direction (X direction) and the vertical direction (Y direction), respectively. The sub-pixels 31 are arranged so that red (R), green (G), and blue (B) are alternately arranged in the row direction (X direction) and the column direction (Y direction).

  In the example shown here, the effective pixels 32 (indicated by a black frame) at the time of displaying a stereoscopic image are configured by the sub-pixels 31 in 9 columns and 3 rows. In such a structure of the display unit, since the effective pixel 32 at the time of stereoscopic video display is composed of 27 sub-pixels, if three color components are required for one parallax, a stereoscopic image / video that gives nine parallaxes in the X direction. Display is possible. The effective pixel refers to a sub-pixel group of the minimum unit that determines the resolution at the time of stereoscopic display, and the element image refers to a set of parallax component images corresponding to one lens. Therefore, in the case of a stereoscopic image display apparatus configured to use a cylindrical lens, one element image includes a large number of effective pixels arranged in the vertical direction.

  As described above, according to the present embodiment, it is possible to keep the distance between the lens and the pixel PX uniform regardless of the use environment. Accordingly, it is an object of the present invention to provide a display device capable of obtaining desired display characteristics.

  In addition, this invention is not limited to the said embodiment itself, In the stage of implementation, it can change and implement a component within the range which does not deviate from the summary. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  For example, in the above-described embodiment, the example in which the first conductive film 203 is disposed on the entire surface of the lens array unit 20 has been described. However, the first conductive film 203 is a strip regardless of the shape of the second conductive film 103. You may form in a shape. In this case, the first conductive film 203 may be disposed only on the top portion or only the bottom portion of the cylindrical lens of the lens array layer 201.

  In the above-described embodiment, the example in which the second conductive film 103 is disposed on the entire surface of the display unit 10 has been described. However, the second conductive film 103 has a strip shape regardless of the shape of the first conductive film 203. Alternatively, it may be formed in a lattice shape and arranged on the display unit 10. Even when the first conductive film 203 and the second conductive film 103 having such shapes are applied, the same effects as those of the present embodiment described above can be obtained. Note that the strip-shaped first conductive film 203 and the second conductive film 103 can be formed by a mask vapor deposition method, so that a complicated photolithography process can be omitted, and the number of steps is greatly increased. Can be avoided.

  In the example illustrated in FIG. 5, the example in which the first conductive film 203 is disposed on the surface of the lens array layer 201 has been described. However, the arrangement position is not limited to such an example. For example, the first conductive film 203 may be disposed on the viewer side of the lens array layer 201, that is, between the lens array layer 201 and the base body 202, or may be disposed on the viewer side of the base body 202. good. In such a case, the lens array layer 201 or the lens array layer 201 and the base body 202 may function as the dielectric layer 400.

  For example, the voltage application unit 500 may apply a voltage at a timing when the power of the display device is turned on, and may apply a voltage constantly during power-on, or may apply a voltage periodically. .

  In the embodiment described above, the voltage application unit 500 may be configured using a circuit provided in the display unit 10 or may be configured as an external circuit.

FIG. 1 schematically shows a configuration of a display device according to an embodiment of the present invention. FIG. 2 is a diagram schematically showing a configuration of a display unit (liquid crystal display panel) applicable to the display device shown in FIG. FIG. 3 is a diagram schematically showing a cross-sectional structure of the display unit shown in FIG. 4A is a perspective view schematically showing a configuration of a lens array unit applicable to the display device shown in FIG. FIG. 4B is a perspective view schematically showing another configuration of the lens array unit applicable to the display device shown in FIG. FIG. 5 is an enlarged view of the region A shown in FIG. FIG. 6 is a diagram showing another configuration of the region shown in FIG. FIG. 7 is a cross-sectional view schematically showing a configuration of an optical element and a second conductive film applicable to the display device shown in FIG. 8A is a cross-sectional view schematically showing a structure of a lens array unit applicable to the display device shown in FIG. 8B is a cross-sectional view schematically showing another structure of the lens array unit applicable to the display device shown in FIG. FIG. 8C is a cross-sectional view schematically showing another structure of the lens array unit applicable to the display device shown in FIG. FIG. 9 is a perspective view schematically showing a partial configuration of the stereoscopic image display apparatus according to the embodiment of the present invention.

Explanation of symbols

DA ... display area PX ... pixel 10 ... display unit (liquid crystal display panel)
11 ... Array substrate (first substrate)
12 ... Counter substrate (second substrate)
DESCRIPTION OF SYMBOLS 13 ... Liquid crystal layer 20 ... Lens array unit 201 ... Lens array layer 202 ... Base | substrate 203 ... 1st electrically conductive film 103 ... 2nd electrically conductive film 400 ... Dielectric layer 500 ... Voltage application part

Claims (6)

A lens array unit having a lens array layer;
A display unit comprising a first substrate and a display unit having a structure in which a second substrate disposed between the first substrate and the lens array unit is bonded,
A light-transmissive first conductive film disposed on the display unit side of the lens array unit;
A second conductive film having optical transparency disposed on the lens array unit side of the display unit;
A dielectric layer disposed between the first conductive film and the second conductive film;
A display device comprising: The lens array unit is disposed so that the lens array layer faces the display unit, and includes the dielectric layer,
The display device according to claim 1, wherein the first conductive film is disposed between the lens array layer and the dielectric layer. The display unit includes the dielectric layer,
The display device according to claim 1, wherein the second conductive film is disposed between the second substrate and the dielectric layer.   The display device according to claim 1, further comprising a voltage applying unit that applies a voltage between the first conductive film and the second conductive film.   The lens array unit is formed by integrally forming a glass base and the glass lens array layer, a glass base having the resin lens array layer bonded to the glass base through an adhesive layer, and 2. The display device according to claim 1, wherein the lens array layer made of a resin is directly molded on a glass substrate.   The display device according to claim 1, wherein the display unit is a liquid crystal display panel.

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