JP3893791B2 - Display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display device such as a liquid crystal display device, and more particularly to a display device capable of enlarging an image.
[0002]
[Prior art]
Some display devices are provided with a light guide for image enlargement between a screen made of a liquid crystal display panel or the like and a screen. FIG. 6 is a perspective view in which a part of an example of such a conventional display device is cut away (see Japanese Patent Laid-Open No. 9-265264). The display device includes a liquid crystal display panel 1 that is appropriately tilted. The liquid crystal display panel 1 basically has a structure in which liquid crystal (not shown) is sealed between a pair of substrates 2 and 3. An edge light type backlight unit 4 is provided on the lower surface side of the liquid crystal display panel 1. The backlight unit 4 has a structure including a light source plate 5 for forming a surface light source, a fluorescent tube 6 and the like. On the upper surface side of the display area of the liquid crystal display panel 1, a light guide 8 is provided that is formed into a side-right triangle by a number of optical fibers 7. The lower surface of the light guide 8 is an incident surface 9, and the inclined surface is an output surface 10 that is inclined at a predetermined angle with respect to the incident surface 9. A refractor 11 and a screen 12 are provided on the light exit surface 10 side of the light guide 8.
[0003]
In this display device, when light is emitted from the upper surface of the light source plate 5 for forming a surface light source of the backlight unit 4, image light corresponding to display driving of the liquid crystal display panel 1 is emitted from the upper surface of the display area of the liquid crystal display panel 1. It is emitted and incident on the incident surface 9 of the light guide 8. The incident image light is emitted from the emission surface 10 of the light guide 8, then refracted in a predetermined direction by the refractor 11 and displayed on the screen 12. In this case, the image light emitted from the upper surface of the display area of the liquid crystal display panel 1 is expanded in a predetermined direction (vertical direction) according to the side surface shape of the light guide 8.
[0004]
[Problems to be solved by the invention]
However, in such a conventional display device, the image of the liquid crystal display panel 1 is enlarged only in a predetermined direction (vertical direction) according to the side shape of the light guide 8. If the structure is the same as a normal one (that is, a single image that is normally displayed as a single unit), the image cannot be enlarged in the horizontal direction, resulting in a wide image in the vertical direction. There is. In addition, there is a method in which the image is expanded in the horizontal direction by the liquid crystal display panel 1 itself, but in this case, the structure of the liquid crystal display panel 1 is different from a normal one and becomes a special one.
The subject of this invention is enabling it to expand the image of a display body to the vertical direction and a horizontal direction.
[0005]
[Means for Solving the Problems]
The present invention comprises a light guide composed of a number of light guide elements, a display body disposed on the incident surface side of the light guide, and a refractor bonded to the exit surface of the light guide element , The light guide element is formed continuously from the entrance surface to the exit surface, and the lateral length of the exit surface is made larger than the lateral length of the entrance surface, and the exit surface is the entrance surface. inclined against the refractor is formed as an inclined surface that transmits without being totally reflected incident light from the incident surface is adhered by the adhesive to the exit surface of the light guide element, and the respective exit surface from each other A continuous plane is formed, the light guide element includes a core made of acrylic resin, and the refractor and the adhesive are formed of the same material as the core or a material having a refractive index similar to the core ; The refractive body is perpendicular to the optical axis of each light guide element of the light guide. A plurality of prism portions each having a plurality of exit surfaces and a surface perpendicular to the exit surfaces, wherein each prism portion is parallel to a line of intersection of each of the exit surfaces and a surface perpendicular to the exit surfaces. it is formed in a line shape or shape that are arranged in a matrix and is characterized in Rukoto. According to this invention, since the exit surface of the light guide is an inclined surface that is inclined with respect to the entrance surface, the image of the display body is enlarged in the vertical direction, and the lateral direction of the exit surface of the light guide is increased. When the length is larger than the length of the incident surface in the horizontal direction, the image on the display body is expanded in the horizontal direction, and therefore the image on the display body can be expanded in the vertical direction and the horizontal direction.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective view in which a part of a main part of a display device according to an embodiment of the present invention is cut out. This display device includes a liquid crystal display panel 21 arranged horizontally. The liquid crystal display panel 21 basically has a structure in which liquid crystal (not shown) is sealed between a pair of substrates 22 and 23, and normally displays a single image by itself. . For example, the ratio of the vertical and horizontal lengths of the display area of the liquid crystal display panel 21 is approximately 3: 4 or approximately 9:16, as in the case of a normal television image display device.
[0007]
An edge light type backlight unit 24 is provided on the lower surface side of the liquid crystal display panel 21. The backlight unit 24 has a structure including a light guide plate 25 for surface light source, a fluorescent tube 26 and the like.
[0008]
A light guide 31 is provided on the upper surface side of the display area of the liquid crystal display panel 21. The light guide 31 is formed continuously by a dense collection of a large number of optical fibers (linear light guide elements) 32, and includes an upper part composed of a right side triangular part 33 and a lower part having a substantially inverted trapezoidal part 34a. 34. In this case, the lower portion 34 has a structure in which flat plate portions 34b and 34c are continuously provided on the lower side and the upper side of the substantially inverted trapezoidal portion 34a. The lower surface of the lower portion 34 is an incident surface 35, and the inclined surface of the side surface right triangle portion 33 is an output surface 36 that is inclined at a predetermined angle with respect to the incident surface 35. In this case, the lateral length of the exit surface 36 is larger by a predetermined magnification than the lateral length of the incident surface side in the lateral direction on the exit surface side of the substantially inverted trapezoidal portion 34a. The height is larger than the lateral length of the incident surface 35 at the same magnification. A method for forming the light guide 31 will be described later.
[0009]
A first refracting body 41, a second refracting body 42 and a screen 43 are provided on the light exit surface 36 side of the light guide 31. Although not shown in detail, the screen 43 is composed of a diffusion plate formed by closely attaching a large number of very small lens portions to the entire surface of one side of the resin sheet.
[0010]
Next, the light guide 31 and the first and second refractors 41 and 42 will be described with reference to FIG. The light guide 31 is composed of a large number of optical fibers 32 formed by covering a core 51 made of a high refractive index acrylic resin with a clad 52 made of a low refractive index fluorine resin. In this case, the angle θ formed by the incident surface 35 and the exit surface 36 of the light guide 31 is about 60 °. Therefore, the length of the exit surface 36 on the side surface of the light guide 31 is twice the length of the entrance surface 35. Correspondingly, the lateral length of the exit surface 36 on the front surface of the light guide 31 is twice the lateral length of the entrance surface 35.
[0011]
A first refracting body 41 is bonded to the emission surface 36 of the light guide 31. The first refracting body 41 is formed of the same material as the core 51 of the light guide 31 or a material having a refractive index similar to that of the core 51, and is arranged on the optical axis (long axis) of each optical fiber 32 of the light guide 31. It consists of a sheet having a large number of prism parts 54 each having a large number of vertical exit surfaces 53 and a surface perpendicular to the exit surface 53. In this case, each prism portion 54 is formed in a dot shape arranged in a linear shape or a matrix shape perpendicular to the paper surface. The first refracting body 41 is made of the same material as that of the core 51 of the light guide 31 or with the emission surface 53 of each prism portion 54 perpendicular to the optical axis of each optical fiber 32 of the light guide 31. The light guide 31 is bonded to the light exit surface 36 by an adhesive (not shown) made of a material having a refractive index similar to that of the core 51. The function of the first refractor 41 prevents the light that has been guided by the optical fiber 32 from being totally reflected by the inclined exit surface 36 of the light guide 31 and returns to the inside of the core 51. The incident light is incident on the first refracting body 41.
[0012]
A second refractor 42 is disposed in close contact with the exit surface 53 side of the first refractor 41. The second refracting body 42 is also formed of the same material as the core 51 of the light guide 31 or a material having a refractive index similar to that of the core 51, and is arranged in a linear or matrix shape perpendicular to the paper surface on the incident surface side. The sheet includes a prism portion 55 formed in a dot shape. Each prism portion 55 has an incident surface 56 and a reflection (refractive) surface 57, and the incident surface 56 of each prism portion 55 is disposed to face the emission surface 53 of each prism portion 54 of the first refracting body 41. Yes. In this state, the emission surface 58 formed by the plane of the second refracting body 42 is parallel to the emission surface 36 of the light guide 31.
[0013]
Next, an example of a method for forming the light guide 31 will be described. First, as shown in FIG. 3, a rectangular parallelepiped optical fiber block 61 in which a large number of optical fibers 32 having the same diameter over the entire length are densely prepared, and the optical fiber block 61 is cut along a one-dot chain line. Two light guide forming blocks 62 are obtained.
[0014]
Next, although not shown, for example, a front heating member, a rear heating member, a lower surface heating member, an upper surface (inclined surface) heating member, and left side heating are provided on each surface of the lower light guide forming block 62 in FIG. The member and the right side heating member are brought into contact with each other and heated at a temperature of about 100 to 120 ° C. for about 30 minutes. Next, both the side surface heating member and the lower surface heating member are removed, and then, as shown in FIG. 4, a pair of left and right heating and pressing members 64 having a predetermined inclined surface 63 on the opposite surface is provided at about 120 to 150 ° C. At a predetermined temperature on both sides of the light guide forming block 62 in the horizontal direction by a predetermined distance (that is, the length of the light guide forming block 62 in the horizontal direction is 1). / 4) (see FIG. 5).
[0015]
Then, the upper part of the light guide forming block 62 is not deformed and becomes a side-right triangular part 62a and a flat part 62b, the central part is deformed to become a substantially inverted trapezoidal part 62c, and the lower part is extended. It becomes a rectangular parallelepiped shaped part 62d. In this case, the cross section in the direction perpendicular to the optical axis of each optical fiber 32 constituting the side surface right triangle portion 62a and the flat plate portion 62b is substantially circular or substantially regular polygonal throughout. The cross section in the direction perpendicular to the optical axis of each optical fiber 32 constituting the substantially inverted trapezoidal portion 62c in the front is substantially circular or substantially regular polygonal on the exit surface side, but the lateral direction is the minor axis on the entrance surface side. It is almost oval or polygonal. The cross section in the direction perpendicular to the optical axis of each optical fiber 32 constituting the rectangular parallelepiped portion 62d is substantially elliptical or substantially polygonal with the transverse direction as the short axis throughout. Next, when the rectangular parallelepiped portion 62d is cut at a predetermined location, the light guide 31 shown in FIG. 1 is obtained.
[0016]
Thus, in this method of forming the light guide 31, the upper part of the light guide forming block 62 is not deformed, but the side surface right-angled triangular part 62 a and the flat part 62 b are formed, and the lower part is deformed and the front is almost inverted. Since the shape portion 62c and the rectangular parallelepiped shape portion 62d are used, it is only necessary to compress and shape the lower portion of the light guide forming block 62 only in the horizontal direction, and thus the light guide 31 can be formed relatively easily.
[0017]
Next, enlarged display of an image by the display device shown in FIG. 1 will be described. When light is emitted from the upper surface of the light source plate for surface light source 25 of the backlight unit 24, image light corresponding to display driving of the liquid crystal display panel 21 is emitted from the upper surface of the display area of the liquid crystal display panel 21 and guided. The light is incident on the incident surface 35 of the body 31. The incident image light passes through the optical fiber 32 of the light guide 31 and is then emitted from the exit surface 36 of the light guide 31.
[0018]
In this case, in the image light emitted from the upper surface of the display area of the liquid crystal display panel 21, the lateral length of the light exit surface 36 of the light guide 31 is twice the lateral length of the incident surface 35. As a result, it is doubled in the horizontal direction. Further, when the image light passes through the optical fiber 32 of the light guide 31, for example, as indicated by an arrow in FIG. 2, the image light travels straight along the optical axis in each core 51 of the light guide 31, and the light guide The first refracting body 41 travels from the exit surface 36 of the 31 and exits from the exit surface 53 of each prism section 54 of the first refracting body 41, and the entrance surface 56 of each prism section 55 of the second refracting body 42. Is incident on. The incident image light is reflected (refracted) by the reflecting surface 57 of each prism portion 55 of the second refracting body 42, and the emitting surface 58 of the second refracting body 42 (that is, the emitting surface 36 of the light guide 31). ) And is enlarged in the vertical direction. In this case, since the angle θ formed between the incident surface 35 and the output surface 36 of the light guide 31 is about 60 °, the image light is magnified twice in the vertical direction.
[0019]
The enlarged image light is emitted from the emission surface 58 of the second refractor 42 in a direction substantially perpendicular to the emission surface 58. The emitted image light passes through the screen 43 and is diffused by a minute lens portion of the screen 43. Then, the diffused image light is visually recognized. Thus, in this display device, even if a normal liquid crystal display panel 21 is used, the image on the liquid crystal display panel 21 can be enlarged twice in the vertical direction and the horizontal direction.
[0020]
In the above-described embodiment, the display image of the liquid crystal display panel 21 is doubled in the vertical direction and the horizontal direction, but may be 3 to 10 times. In this case, expansion in the vertical direction by the light guide 31 and the first and second refractors 41 and 42 is relatively easy, but each optical fiber 32 is expanded in the horizontal direction by the light guide 31. As the compression ratio increases, it becomes difficult to make the deformation uniform. In this case, the liquid crystal display panel 21 may be obtained by reducing the display image only in the vertical direction. For example, if a liquid crystal display panel whose display image is reduced to 1/5 in the vertical direction is used, the display image is reduced to 1/5 in the vertical direction. When enlarged, the image emitted from the emission surface 36 of the light guide 31 is enlarged ten times in the horizontal direction. Therefore, if the light guide 31 and the first and second refractors 41 and 42 are enlarged 10 times in the vertical direction, an image enlarged 10 times in the vertical and horizontal directions is projected on the screen 43.
[0021]
Moreover, although the said embodiment demonstrated the case where the light guide 31 was formed densely of many optical fibers 32, not only this but many thin plate-shaped light guide elements which have a clad | crud or a reflecting film in the front and back surfaces May be formed by stacking in the thickness direction and compressing and shaping the lower part in the stacking direction (lateral direction).
[0022]
Moreover, although the said embodiment demonstrated the case where the light guide 31 was made into the left-right symmetric shape, it does not need to be a left-right symmetric shape, the point is that the horizontal length of the output surface 36 is the incident surface 35. It only needs to be larger than the lateral length of.
[0023]
Moreover, although the said embodiment demonstrated the case where the one liquid crystal display panel 21 was used, it is not limited to this. For example, two sets of those shown in FIG. 1 excluding the screen 43 may be arranged on the left and right, and one image may be displayed on one screen. In addition, two of the ones shown in FIG. 1 excluding the screen 43 are arranged on the left and right, and the upper side of the one shown in FIG. One image may be displayed on one screen.
[0024]
Furthermore, as a display body, an EL display, an LED display, a plasma display, a CRT display, or the like may be used in addition to the liquid crystal display panel.
[0025]
【The invention's effect】
As described above, according to the present invention, since the expanding in the vertical and horizontal direction image of the display by the light guide body, it is possible to use a conventional and a display body, also, the light guide body the manufacturing process is greatly simplified, and thus, increases the yield of production of the display device having a light guide, Ru can reduce the manufacturing cost of a display device including a light guide.
[Brief description of the drawings]
FIG. 1 is a perspective view in which a part of a main part of a display device according to an embodiment of the present invention is cut away.
FIG. 2 is a longitudinal side view of a part of the light guide and first and second refractors shown in FIG.
FIG. 3 is a perspective view showing an optical fiber block prepared at the time of forming the light guide shown in FIG. 1;
FIG. 4 is a perspective view for explaining a forming process subsequent to FIG. 3;
5 is a perspective view for explaining a forming step subsequent to FIG. 4. FIG.
FIG. 6 is a perspective view in which a part of an example of a conventional display device is cut away.
[Explanation of symbols]
21 liquid crystal display panel 24 backlight unit 31 light guide 32 optical fiber 33 side surface right triangle part 34a front substantially inverted trapezoidal part 41 first refractor 42 second refractor 43 screen

Claims (5)

A light guide body including a plurality of light guide elements; a display body disposed on an incident surface side of the light guide body; and a refractor bonded to an output surface of the light guide element, the light guide element Is formed continuously from the entrance surface to the exit surface, and the lateral length of the exit surface is larger than the lateral length of the entrance surface, and the exit surface is inclined with respect to the entrance surface. , is an inclined surface that transmits without the refractor is totally reflects the incident light from the incident surface is adhered by the adhesive to the exit surface of the light guide element, and, one plane each exit surface continuous with each other forming a light guiding element includes a core made of an acrylic resin, the refractive body and the adhesive is formed of a material having a refractive index that approximates the same material or core and the core, the refractive body A plurality of emission surfaces perpendicular to the optical axis of each light guide element of the light guide The sheet comprises a sheet having a plurality of prism portions each having a surface perpendicular to the exit surface, and each prism portion is a line or matrix parallel to the intersection line between each exit surface and a surface perpendicular to the exit surface. display device comprising Rukoto formed in shape that are arranged to Jo.   In the first aspect of the present invention, the light guide body includes a large number of linear light guide elements, and the cross section in the direction perpendicular to the optical axis of each linear light guide element constituting the light guide body is substantially on the exit surface side. A display device having a circular shape or a substantially regular polygon shape and a substantially elliptical shape or a substantially polygonal shape having a short axis in the lateral direction on the incident surface side.   2. The light guide according to claim 1, wherein the light guide includes an upper portion having a right side triangular shape and a lower portion having a front substantially inverted trapezoidal portion, and a lower surface of the lower portion serves as an incident surface, and the upper inclined surface. Is a light emitting surface.   4. The display device according to claim 1, wherein a vertical enlargement ratio and a horizontal enlargement ratio by the light guide are the same.   5. The display device according to claim 4, wherein the display body is a single display that normally displays one image.

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