JP2008076736A - Display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display element by which only a correct image can be displayed easily while the range of directions generating image crosstalk is reduced. <P>SOLUTION: Images different between a pixel group of a plurality of pixels 29a and an image group of a plurality of pixels 29b at alternate positions in a display device 21 are displayed in different viewing-angle directions. On the side of a display surface 30 of the display device 21, a first parallax barrier layer 33 is provided which cuts off a different image displayed by a different pixel group in the respective viewing angle directions. On the opposite side to the display surface 30 of the display device 21, a second parallax barrier layer 36 is provided which cuts off the images displayed by the respective pixel groups of the display device 21 in directions different from the viewing angle directions wherein the first parallax barrier layers 33 cut off the image. Through the first and second barrier layers 33 and 36, an image displayed by one pixel group can be recognized when viewed from a predetermined viewing angle direction, but the other image displayed by the other pixel group is cut off. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a display element capable of displaying different images in each direction when observed from different directions.

  Conventionally, for example, a display such as a liquid crystal display element is generally used as a large display such as a personal computer and a television receiver from a small display such as a mobile phone, a personal digital assistant (PDA), and a car navigation system. .

  Previous displays have been optimized to enable high-quality observation of the same image from different angles, but in recent years this has been called multiple-view display, which displays multiple different images simultaneously and observes individual images depending on the viewing angle direction. There is also a need for a display that can be used. For example, a vehicle-mounted display mounted on a car has a use such that a passenger in a passenger seat watches a movie or the like in addition to a car navigation data such as a map and monitor confirmation.

  As such a multiple view display, conventionally, a display device that displays a plurality of images at the same time, and an optical device that separates and displays each image by parallax so that the images are individually viewed from a predetermined viewing angle direction, are provided. There is something to prepare.

  For example, as a display device, there is an active matrix TFT liquid crystal display element or the like having a general RGB stripe structure. Among a plurality of pixels included in such a display device, for example, a plurality of lines in a direction in which an image is separated by parallax. A plurality of pixel groups are constituted by a plurality of pixels alternately positioned every time, and an individual image is displayed by each pixel group. In addition, as an optical device, there is a parallax barrier layer in which a light shielding portion that shields pixels of a display device and a slit portion that transmits light are alternately formed, and only one parallax barrier layer is formed on the front side of the display device. (For example, refer to Patent Document 1).

For example, when viewed from a predetermined viewing angle direction on one side with respect to the front of the multiple view display, only the image of one pixel group is visually recognized through the slit portion, and the image of the remaining pixel group is shielded from the parallax barrier layer. It is shielded from light at the part. Similarly, when viewed from the predetermined viewing angle direction on the other side with respect to the front of the multiple view display, only the image of one pixel group is viewed through the slit portion, and the image of the remaining pixel group is shielded from the parallax barrier layer. It is shielded from light at the part. Accordingly, different images can be observed through the slit portion from different directions with one multiple view display.
JP-A-11-205822

  However, in the multiple view display, each image is separated and displayed by parallax so that the images are individually viewed from a predetermined viewing angle direction using a single parallax barrier layer, but the viewing angle direction is designed. When deviating from the specified direction, image crosstalk appears in which a plurality of images appear to be overlapped with each other, so that normal display quality cannot be obtained, and different information may be given to the observer or discomfort may be caused. For example, when viewed from a predetermined viewing angle direction, only an image of one pixel group is visually recognized, but when viewed from a predetermined viewing angle direction, other adjacent pixel groups together with an image of one pixel group These images are also seen together, and image crosstalk appears in which a plurality of images are overlapped. In particular, with only one parallax barrier layer, there is a tendency that the range in the viewing angle direction in which image black strokes occur is relatively wide including the front direction of the display surface.

  SUMMARY An advantage of some aspects of the invention is that it provides a display element that can easily display only a correct image by reducing a range in a direction in which an image black stroke occurs.

  The present invention includes a display element body having a plurality of pixels, and capable of displaying different images in different viewing angle directions for each of a plurality of pixel groups constituted by a plurality of pixels alternately positioned among these pixels. A first parallax barrier layer that is formed on a display surface side of the display element body and shields different images displayed by the different pixel groups in each viewing angle direction; and the first parallax barrier layer of the display element body; A second parallax barrier layer that is formed on the opposite surface side and shields an image displayed in each pixel group of the display element body in a direction different from a viewing angle direction shielded by the first parallax barrier layer. It is what.

  The first and second parallax barrier layers function as a light-shielding unit for parallax, and an image displayed in one pixel group is viewed when viewed from a predetermined viewing angle direction, but is displayed in a different pixel group. The image is shielded from light by the parallax barrier layer. In addition, the first and second parallax barrier layers reduce the occurrence of image cross strokes when viewed from a predetermined viewing angle direction.

  According to the present invention, the first and second parallax barrier layers can reduce the range of the direction in which the image black stroke occurs and can easily display only a correct image.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As illustrated in FIG. 1, a multiple view display 10 as a display device includes a display element 11 and a backlight 12 that illuminates from the back side of the display element 11.

  The display element 11 is a display device 21 that is a liquid crystal cell as a display element body that displays a plurality of images at the same time, and an image for separating images so that images displayed on the display device 21 from different viewing angle directions can be individually viewed Optical devices 22a and 22b are provided as optical elements.

  For the display device 21, for example, an active matrix TFT liquid crystal display element having a general RGB stripe structure is used. The display device 21 has a structure in which a liquid crystal layer 26 is sandwiched between an array substrate 24 and a counter substrate 25 that are held at regular intervals by spacers. In the array substrate 24, scanning lines and signal lines are formed on a transparent glass substrate 27 as a first substrate, and TFTs as pixel electrodes and switching elements are formed in a matrix. . In the counter substrate 25, a striped color filter of RGB colors, an ITO electrode, and the like are formed on a transparent glass substrate 28 as a second substrate. The array substrate 24 and the counter substrate 25 are combined to form a plurality of pixels 29 arranged in a matrix, and the plurality of pixels 29 constitute a display surface 30 for displaying an image.

  The display device 21 can display, for example, an interlaced image by a drive circuit (not shown), and can also display a plurality of different images. That is, among the plurality of pixels 29, for example, a pixel group composed of a plurality of pixels 29a and a plurality of pixels 29b that are alternately positioned one line at a time in a direction in which an image is separated by parallax such as a left-right direction. And two pixel groups, and individual images can be displayed by each pixel group.

  The optical device 22a is formed on the display surface 30 side of the display device 21, that is, the first parallax barrier layer 33 is formed on the surface of the substrate 28 of the display device 21 via the transparent adhesive layer 32. The formed transparent glass substrate 34 is bonded. On the other hand, the optical device 22b is formed on the light source side surface 31 side opposite to the display surface 30 side of the display device 21, that is, on the surface of the substrate 27 of the display device 21 via the transparent adhesive layer 35. A transparent glass substrate 37 on which the second parallax barrier layer 36 is formed is bonded.

  The substrate 28 and the adhesive layer 32 of the display device 21 are formed as a first distance adjustment layer 38 that separates the color filter of the display device 21 and the first parallax barrier layer 33 by a predetermined distance. The color filter, the liquid crystal layer 26, the substrate 27, and the adhesive layer 35 are formed as a second distance adjustment layer 39 that separates the second parallax barrier layer 36 by a predetermined distance.

  Each of the parallax barrier layers 33 and 36 is formed in parallel to the front surface of the display device 21, and has a plurality of light shielding portions 40 formed at intervals in a direction in which an image is separated by parallax such as a left-right direction. A plurality of slit portions 41 are formed between the light shielding portions 40. Each slit portion 41 is filled with adhesive layers 32 and 35. Each of the parallax barrier layers 33 and 36 is formed by laminating a resin in which a black pigment such as chromium or carbon black, which is a non-light transmissive metal, is dispersed on the substrates 34 and 37, and patterning using a photolithography method. Is formed. Alternatively, a black pigment such as carbon black is directly patterned on the substrates 34 and 37 using an ink jet method.

  In each of the parallax barrier layers 33 and 36, the range of the direction in which an image is separated by parallax is the distance from the color filter of the display device 21 to the first parallax barrier layer 33, or from the color filter to the second parallax barrier layer 36. Therefore, management of the thickness of the adhesive layers 32 and 35 is important. The material used for the adhesive layers 32 and 35 is preferably, for example, an acrylic ultraviolet curable resin. Furthermore, it is desirable that the substrates 27 and 28 of the display device 21 and the substrates 34 and 37 used as the first and second distance adjustment layers 38 and 39 have the same refractive index. In addition, it is desirable that the acrylic ultraviolet curable resin used for the adhesive layers 32 and 35 has the same refractive index as that of the substrates 27, 28, 34 and 37.

  As shown in FIG. 2, the first parallax barrier layer 33 is arranged so that the center line of the light shielding part 40 and the center line of the slit part 41 coincide with the center line of the black matrix BM formed between the pixels 29. It is positioned.

  As shown in FIG. 3, the second parallax barrier layer 36 is different from the first parallax barrier layer 33 in that the position of the light shielding portion 40 and the position of the slit portion 41 are different. The center line of the light shielding part 40 and the center line of the slit part 41 are positioned so as to coincide with the center line of the slit part 41 and the center line of the light shielding part 40 of the first parallax barrier layer 33, respectively. That is, the entire image displayed by each pixel group of the display device 21 on the display surface 30 of each display device 21 is displayed on the display surface 30 of the display device 21 by each light shielding unit 40 of the first parallax barrier layer 33 and each light shielding unit 40 of the second parallax barrier layer 36. The light is shielded in the vertical front direction.

  The width of the pixel 29, the width of the black matrix BM of the pixel 29, the opening width of the slit portion 41 of the first and second parallax barrier layers 33, 36, the distance between the color filter and the first parallax barrier layer 33, It is preferable that the relationship of the distance between the first parallax barrier layer 33 and the second parallax barrier layer 36 is a relationship represented by the following equations (1) and (2).

(1) (Opening width of slit portion 41 of first parallax barrier layer 33, width of light shielding portion 40 of second parallax barrier layer 36) = (width of pixel 29) − (width of black matrix of pixel 29)
(2) (Distance between the color filter and the first parallax barrier layer 33, distance between the color filter and the second parallax barrier layer 36) = (width of the pixel 29) ÷ 2 ÷ {tan (sin −1 [sin θ ÷ ng])}
θ: desired pixel separation range center angle ng: glass refractive index

  The optical device 22a is disposed on the front side of the display device 21, and the optical device 22b is disposed on the back side of the display device 21. A light source side polarizing plate 43 is formed on the back surface of the display device 21, that is, the back surface of the substrate 37, and an observer side polarizing plate 44 is provided on the front surface of the optical device 22a, that is, the surface of the substrate.

  The backlight 12 includes a light source 51 and a light guide plate 52 that receives light from the light source 51 and emits the light from a surface facing the back side of the display element 11.

  Next, the operation of the present embodiment will be described.

  First, a method for manufacturing the display element 11 will be described.

  For example, the substrate 28 on the front side of the display device 21 having a pixel pitch of 63.5 μm and a pixel black matrix BM width of 12 μm is chemically or mechanically polished to a thickness of 55 μm to form part of the first distance adjustment layer 38. To do.

  On the surface of the substrate 28, for example, a material such as an ultraviolet curable resin for the adhesive layer 32 is applied to a thickness of 35 μm. Further, a substrate 34 on which a first parallax barrier layer 33 having an opening width of 40 μm of the slit portion 41 and a width of 87 μm of the light-shielding portion 40 is previously formed by patterning on the surface side of the substrate 28 through the adhesive layer 32, for example. Adhere closely. The first parallax barrier layer 33 formed on the substrate 34 is formed by laminating a resin in which a black pigment such as chromium or carbon black, which is a non-light transmissive metal, is dispersed on the substrate 34 and using a photolithography method. Or a black pigment such as carbon black is directly patterned on the substrate 34 using an inkjet method. At this time, as shown in FIG. 2, the first parallax barrier layer 33 is bonded so that the center line of the light shielding part 40 and the center line of the slit part 41 coincide with the center line of the black matrix BM between the pixels 29. .

  By attaching the substrate 34 to the display device 21, the first distance adjustment for separating the color filter of the display device 21 and the first parallax barrier layer 33 by a predetermined distance by the substrate 28 and the adhesive layer 32 of the display device 21. Layer 38 is formed.

  For example, if the thickness of the liquid crystal layer 26 and the color filter is 5 μm, the substrate 27 of the display device 21 is chemically or mechanically polished until the thickness reaches 50 μm, thereby forming a part of the second distance adjustment layer 39. To do.

  For example, a material such as an ultraviolet curable resin for the adhesive layer 35 is applied to the surface of the substrate 27 to a thickness of 35 μm. Further, the substrate 37 on which the second parallax barrier layer 36 having the opening width of 87 μm of the slit portion 41 and the width of 40 μm of the light shielding portion 40 is previously patterned is adhered to the surface side of the substrate 37 through the adhesive layer 35. Let them stick together. The second parallax barrier layer 36 formed on the substrate 37 is formed by, for example, laminating a resin in which a black pigment such as chromium or carbon black, which is a non-light transmissive metal, is dispersed on the substrate 37 and using a photolithography method. Or a black pigment such as carbon black is directly patterned on the substrate 37 using an inkjet method. At this time, as shown in FIG. 3, the second parallax barrier layer 36 is different from the first parallax barrier layer 33 in that the position of the light shielding part 40 and the position of the slit part 41 are different. The layer 36 is bonded so that the center line of the light shielding part 40 and the center line of the slit part 41 coincide with the center line of the slit part 41 of the first parallax barrier layer 33 and the center line of the light shielding part 40, respectively.

  The display element 11 is combined with the polarizing plates 43 and 44 and the backlight 12 to form a multiple view display 10.

  FIG. 4 shows a state where the first and second parallax barrier layers 33 and 36 separate the images so that the images displayed on the display device 21 are individually viewed from the left and right viewing angle directions.

  In the multiple view display 10, among a plurality of pixels 29, a pixel group composed of a plurality of pixels 29a and a pixel group composed of a plurality of pixels 29b that are alternately positioned one line at a time in the direction of separating an image by parallax; To display different images.

  The first parallax barrier layer 33 blocks light emitted from the backlight 12 and transmitted through the pixel 29, and the second barrier layer 36 blocks light emitted from the backlight 12 before reaching the pixel 29.

  The first and second parallax barrier layers 33 and 36 allow each image to be viewed with good display quality when viewed from the left viewing angle direction and the right viewing angle direction. That is, when viewed from the left viewing angle direction, the image R displayed by the pixel group of the plurality of pixels 29a is shielded by the light shielding unit 40 of the first and second parallax barrier layers 33 and 36, and the plurality of pixels The image L displayed by the pixel group 29b is visible through the slit portions 41 of the first and second parallax barrier layers 33 and 36. On the other hand, when viewed from the right viewing angle direction, the image L displayed by the pixel group of the plurality of pixels 29b is shielded by the first and second parallax barrier layers 33 and 36, and the pixel group of the plurality of pixels 29a is displayed. The image R displayed in (1) can be viewed through the slit portions 41 of the first and second parallax barrier layers 33 and 36.

  In this case, the first and second parallax barrier layers 33 and 36 can sufficiently regulate the region where the image black stroke in which the left image L and the right image R are mixed is generated, as compared with the case of one layer. Therefore, only a correct image can be easily displayed.

  Therefore, when this multiple view display 10 is used for an application such as car navigation, it is possible to reduce the observation of an image in which the image L and the image R are mixed from the driver, giving different information to the driver and discomfort. Can reduce the risk of

  In addition, the entire image displayed on each pixel group of the display device 21 by the light shielding portions 40 of the first parallax barrier layer 33 and the light shielding portions 40 of the second parallax barrier layer 36 is displayed on the display surface 30 of the display device 21. Since the light is shielded in the vertical front direction, the left and right images are completely separated when viewed from the front direction, so that the separability is high and the occurrence of image cross strokes can be reduced.

  Note that each of the first parallax barrier layer 33 and the second parallax barrier layer 36 is not limited to a single layer but may be formed of two or more layers, and the region where the image cross stroke occurs can be further narrowed.

  Further, the display device 21 is not limited to the active matrix TFT liquid crystal display element, and other display elements can be used.

1 is a cross-sectional view of a display device using a display element according to an embodiment of the present invention. It is a front view which shows the positional relationship of the pixel of a display element same as the above, and a 1st parallax barrier layer. It is a front view which shows the positional relationship of the 1st parallax barrier layer of a display element same as the above, and a 2nd parallax barrier layer. It is explanatory drawing which shows the effect | action of the 1st and 2nd parallax barrier layer of a display element same as the above.

Explanation of symbols

11 Display element
21 Display device as display element body
29 pixels
30 Display surface
33 First parallax barrier layer
36 Second parallax barrier layer
40 Shading part

Claims (2)

A display element body having a plurality of pixels, and capable of displaying different images in different viewing angle directions for a plurality of pixel groups composed of a plurality of pixels alternately positioned among these pixels;
A first parallax barrier layer that is formed on the display surface side of the display element body and shields different images displayed in the different pixel groups in each viewing angle direction;
The display element body is formed on a surface opposite to the first parallax barrier layer, and is displayed in a direction different from a viewing angle direction in which an image displayed on each pixel group of the display element body is shielded by the first parallax barrier layer. And a second parallax barrier layer for shielding light. Each of the first parallax barrier layer and the second parallax barrier layer has a plurality of light shielding portions, and the light shielding portions of the first parallax barrier layer and the light shielding portions of the second parallax barrier layer are displayed on the display. The display element according to claim 1, wherein the entire image displayed in each pixel group of the element body is shielded in a direction perpendicular to a display surface of the display element body.

Images