JP2010272274A - Backlight unit for color liquid crystal display device, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a backlight unit for a color liquid crystal display device, easier to manufacture while omitting a color filter to actualize higher screen brightness. <P>SOLUTION: In the backlight unit 3, optical fiber cables 17, 18, 19 corresponding to three primary colors are arranged in accordance with the arrangement order of red, green and blue sub pixels R, G, B arranged in parallel to one another to form one pixel 13 for a color liquid crystal shutter 2, and along their arraying direction. The optical fiber cables 17, 18, 19 each have a plurality of grooved holes 23 for reflecting light guided along their axial directions toward the color liquid crystal shutter 2. Spaces between the grooved holes 23 of the red light optical fiber cable 17 are the same as spaces between the red sub pixels R, spaces between the grooved holes 23 of the green light optical fiber cable 18 are the same as spaces between the green sub pixels G, and spaces between the grooved holes 23 of the blue light optical fiber cable 19 are the same as spaces between the blue sub pixels B. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a structure of a backlight unit used in a color liquid crystal display device, and more particularly to a structure of a backlight unit capable of increasing screen luminance while suppressing power consumption and a method for manufacturing the backlight unit.

  Nowadays, liquid crystal display (LCD) devices are widely used as display devices for televisions, personal computers, mobile phones and the like. As a technique for performing color display with this type of liquid crystal display device, a backlight unit (BLU) is used. A method of displaying an arbitrary color by causing white light emitted from the light to enter a color filter (CF) provided in each pixel in the liquid crystal cell and separately controlling the light transmittance of each pixel. Until now it was common.

  However, in such a color display method, since the color filter absorbs light emitted from the backlight unit and the brightness of the liquid crystal screen is relatively lowered, a high brightness is required to increase the screen brightness. Since the backlight unit was required, there was a problem that the amount of power consumed by the backlight unit was relatively large.

  For this reason, for example, as disclosed in Patent Document 1, the color filter itself is omitted, and light of the three primary colors emitted from the light source is directly incident on the corresponding pixel of the liquid crystal display panel and the light amount is controlled by the liquid crystal panel. Thus, a backlight unit of a color liquid crystal display device having a structure for performing color display has already been invented and is publicly known.

JP 2007-156024 A

  The pixels of the color liquid crystal display device are composed of sub-pixels corresponding to the three primary colors, and the width along the short direction of each sub-pixel is generally about 100 micrometers. The backlight described in Patent Document 1 requires a structure that emits three primary color lights having a fine width of about 100 micrometers in a strip shape.

  In this regard, the backlight described in Patent Document 1 is a light guide having a width of about 100 micrometers along the short direction, and is divided by about 15 micrometers along the short direction. The light guides corresponding to the three primary colors are used for the light sourced from the light emitting diodes of the red light emitting diode, the green light emitting diode, and the blue light emitting diode by the light shielding film provided in each light guiding portion. A light guide plate having a structure to be incident on the part is proposed.

  And in patent document 1, in order to manufacture the said light-guide plate, after forming a groove | channel with a metal mold, it performs light reflection or light-shielding processing, or performs exposure and development processing by apply | coating a resist to a light-guide plate, It has been proposed to form grooves by etching the light guide plate using this resist pattern as a mask.

  However, as proposed in Patent Document 1, in the case of performing light reflection or light shielding treatment after forming a groove with a mold, an extremely narrow groove having a width along the short side direction of about 15 micrometers. Is required to be formed with high dimensional accuracy, and it is difficult to form a groove. In addition, when a method of storing a thin member such as a metal foil film having a thin light reflection or light shielding property in order to perform reflected light or light shielding treatment in this groove, the metal foil film is arranged along the longitudinal direction of the groove. Therefore, it is difficult to store in the groove in a state of extending straight.

  In addition, as proposed in Patent Document 1, when the light guide plate is exposed and developed by applying a resist to the light guide plate, and the light guide plate is etched using the resist pattern as a mask, the width along the short direction. It is difficult to apply the resist to the light guide plate so that a very narrow gap of about 15 micrometers is opened, and when the light guide plate is etched, the width along the short direction of the groove is from the upper end. A high dimensional accuracy is required in order to uniformly reach the lower end of about 15 micrometers.

  For this reason, in the method of manufacturing the light guide plate proposed in Patent Document 1, it is extremely difficult to manufacture the light guide plate, and processing such as light reflection or shading treatment, resist coating, etching, or the like is required. The process is complicated, and there is a problem that these processes require time.

  Accordingly, an object of the present invention is to provide a backlight unit of a color liquid crystal display device in which a color filter is omitted in order to enhance screen luminance and the manufacture is facilitated, and a method for manufacturing the backlight unit.

  The backlight unit of the color liquid crystal display device according to the present invention includes a long red light guide for guiding light using a red light emitter as a light source, and a long body for guiding light using a green light emitter as a light source. In a backlight unit of a color liquid crystal display device using a green light guide for green light and a long blue light guide for guiding light using a blue light emitter as a light source, the red light guide The light guide for green light and the light guide for blue light follow the arrangement order of the sub-pixels for red, green and blue arranged in parallel to form one pixel of the color liquid crystal shutter, and The red light guide is arranged so as to be planar along the arranged direction, and the red light guided along the longitudinal direction of the red light guide is supplied to the red light guide. Plural light reflecting means for reflecting in the direction of color liquid crystal shutter The green light guide is formed with a plurality of light reflecting means for reflecting the green light guided along the longitudinal direction of the green light guide in the direction of the color liquid crystal shutter. The blue light guide is formed with a plurality of light reflecting means for reflecting the blue light guided along the longitudinal direction of the blue light guide in the direction of the color liquid crystal shutter. The distance between the light reflecting means of the red light guide is the same as the distance between the red sub-pixels so that the light reflected by the light reflecting means is incident on the red sub-pixels. And the interval between the light reflecting means of the green light guide is the same as the interval between the green sub-pixels so that the light reflected by the light reflecting unit is incident on the green sub-pixel. Dimensions, and further, each light reflecting means of the blue light guide The septum, the light reflected by the reflecting means is characterized by the way is incident on the sub-pixel for blue, it has the same dimensions as the spacing of the sub-pixels to a the blue (claim 1). Here, the red light emitter refers to, for example, a red light emitting diode (LED), the green light emitter refers to, for example, a green light emitting diode (LED), and the blue light emitter refers to, for example, a blue light emitting diode (LED). . Each light guide includes, for example, a core that guides light using a light emitting body that emits one of red, green, and blue as a light source, and a cladding having a lower refractive index than that of the core. An optical fiber cable is applicable. In addition, the light guide body covers, for example, a substantially rectangular parallelepiped core that guides light using a light emitting body that emits one of red, green, and blue as a light source, and the periphery of these cores except for one surface thereof. This corresponds to an optical waveguide formed of a clad having a single plate shape and a plurality of linear strip-like grooves into which the core can be inserted and engaged, and having a lower refractive index than each core. Further, the light reflecting means refers to a groove formed by cutting out a triangular shape on the side surface of the light guide opposite to the color liquid crystal shutter or on the same side as the color liquid crystal shutter by laser processing or the like. . The same applies to the following.

  As a result, each light guide does not need to be arranged along the arrangement direction of sub-pixels for the same color among the sub-pixels. Disappears. Further, since the light reflecting means column formed on the light guide is formed so as to be aligned along the arrangement direction of the red sub-pixel, the green sub-pixel, and the blue sub-pixel, the light reflecting means and the light reflecting means Since the interval between the sub-pixels can be determined according to the width of the sub-pixels in a relatively short direction, the number of pixels can be relatively increased even on a screen of the same area such as a television. It becomes possible.

  The backlight unit of the color liquid crystal display device according to the present invention has a thickness between the light guide for red light, the light guide for green light, the light guide for blue light, and the color liquid crystal shutter. A relatively thin light diffusing structure is interposed, and this light diffusing structure is located along the longitudinal direction of the red sub-pixel at a portion facing the light reflecting means of the red light guide. At least an anisotropic light diffusing unit that diffuses light but suppresses light diffusion is provided in the short direction, and the length of the green sub-pixel is located at a portion facing the light reflecting unit of the green light guide line. At least an anisotropic light diffusing means for diffusing light along the direction but suppressing light diffusion in the short direction is provided, and the blue light guide line is provided with a portion for the blue light at a portion facing the light reflecting means. Along the longitudinal direction of the sub-pixel There is diffused is characterized by comprising an anisotropic light-diffusing means for diffusing the light is suppressed in the lateral direction (Claim 2). The anisotropic diffusing unit is formed by using a high-performance diffusing lens film that has been processed at least in a region that intersects the direction in which light is incident from the light guide and that the incident light from the light guide reaches. A plurality of convex semi-cylindrical lenses are arranged on the surface that intersects the incident direction of the light from the light guide and the part where the incident light from the light guide reaches. And the one formed by using the lenticular lens array (Claim 4).

  As a result, even when the light reflected by the light reflecting means arranged at a distance from the light guide is emitted toward the color liquid crystal shutter, the same light guide is provided by the anisotropic light diffusing means of the light diffusing structure. In the direction along the longitudinal direction of the body, the light reflected and emitted by the light reflecting means is continuous by diffusing each other in a substantially fan shape, so that even when the light guide is viewed from the light emitting direction, light is emitted. Can be prevented from being emitted in a scattered manner, and light from other light guides is not diffused between adjacent sub-pixels. It is not necessary to use light shielding means.

  In addition, the method for manufacturing the backlight unit of the color liquid crystal display device according to the present invention includes a long red light guide for guiding light using a red light emitter as a light source, and light using a green light emitter as a light source. Of a backlight unit of a color liquid crystal display device using a long green light guide for guiding light and a long light guide for blue light using a blue light emitter as a light source In the method, the light guided along the longitudinal direction of the light guide to the light guide is directed to a color liquid crystal shutter including a plurality of pixels having red, green, and blue sub-pixels. A plurality of light reflecting means for reflecting the light, and the distance between the light reflecting means of the red light guide is the same as the distance between the red sub-pixels. The light reflecting means is spaced between the green sub-pixels. And the step of setting the distance between the light reflecting means of the blue light guide to the same dimension as the distance between the blue sub-pixels, and the light guide to the surface of the color liquid crystal shutter. Along the direction and order in which the sub-pixels are arranged, and regularly arranged in a planar shape, and the reflection means of the red light guide is emitted from the light reflection means. Is positioned so as to be incident on the red sub-pixel, and the reflecting means of the light guide for green light is positioned so that light emitted from the light reflecting means is incident on the green sub-pixel, Furthermore, the step of positioning the reflecting means of the blue light guide so that the light emitted from the light reflecting means is incident on the blue sub-pixel, the red light guide, and the green light Light guide, blue light guide and color liquid crystal A step of interposing a light diffusing structure provided with an anisotropic light diffusing means that diffuses light along the longitudinal direction of the sub-pixel between the shutter and the light in the short direction; (Claim 5).

  Thereby, a groove is formed between the light guide and the inner surface of the groove is subjected to light reflection or light shielding treatment, or a member such as a metal foil film having light shielding properties is disposed. Since the configuration can be omitted and each process is relatively simple, the manufacturing time and the manufacturing cost of the backlight unit of the color liquid crystal display device can be shortened.

  As described above, according to the first aspect of the present invention, the light guides do not need to be arranged along the arrangement direction of the sub-pixels for the same color among the sub-pixels. Need not be set to be smaller than the dimension of the sub-pixel in the short direction. Further, since the light reflecting means column formed on the light guide is formed so as to be aligned along the arrangement direction of the red sub-pixel, the green sub-pixel, and the blue sub-pixel, the light reflecting means and the light reflecting means Since the interval between the sub-pixels can be determined according to the width of the sub-pixels in a relatively short direction, the number of pixels can be relatively increased even on a screen of the same area such as a television. Thus, it is possible to further improve the image quality of a color liquid crystal display device such as a television.

  In particular, according to the second aspect of the present invention, a thickness is relatively between the red light guide, the green light guide, the blue light guide, and the color liquid crystal shutter. A thin light diffusing structure is interposed, and this light diffusing structure allows light to pass along the longitudinal direction of the red sub-pixel at a portion facing the light reflecting means of the light guide for red light. At least an anisotropic light diffusing means for diffusing but suppressing light diffusion is provided in the short direction, and along the longitudinal direction of the green sub-pixel at a portion facing the light reflecting means of the green light guide line At least an anisotropic light diffusing means for suppressing light diffusion in the short direction is provided in the short direction, and the blue sub-pixel is disposed at a portion facing the light reflecting means of the blue light guide line. Light diffuses along the longitudinal direction, but diffuses in the short direction Even in the configuration in which the anisotropic light diffusing means to be suppressed is provided, the anisotropic light diffusing means of the light diffusion structure is reflected by the light reflecting means and emitted in the direction along the longitudinal direction of the same light guide. Since the light is continuous by diffusing each other in a substantially fan shape, even when the light guide is viewed from the light emission direction, it is possible to avoid light being emitted in a scattered manner and adjacent to each other. Since the light from other light guides is not diffused to the matching sub-pixels, it is not necessary to arrange a light shielding means between the light guides and the backlight of the color liquid crystal display device It is possible to reduce the number of manufacturing steps of the unit and the manufacturing cost.

  According to the fifth aspect of the present invention, a groove is formed between the light guides and the inner surface of the groove is subjected to light reflection or shading treatment, or has a light shielding property. Since the configuration of arranging a member such as a foil film can be omitted and each process is relatively simple, the manufacturing time of the backlight unit of the color liquid crystal display device can be shortened and the manufacturing cost can be reduced. You can plan.

  Furthermore, according to the invention described in claims 1 to 5, since the color filter is omitted, the light absorption rate from the backlight to the color liquid crystal shutter can be suppressed by the absence of the color filter. Accordingly, since the luminance of the backlight can be relatively suppressed, it is possible to save power in the color liquid crystal display device.

FIG. 1 is a schematic view of an example of a color liquid crystal display device using a backlight unit according to the present invention. FIG. 2 is a schematic diagram showing the configuration and arrangement of the pixels in the color liquid crystal shutter of the same color liquid crystal display device and the sub-pixels forming each pixel. FIG. 3 is a schematic view of a cross section of the same color liquid crystal display device. FIG. 4 is an enlarged cross-sectional view corresponding to one pixel of FIG. FIG. 5 is an explanatory diagram showing how the color liquid crystal shutters are arranged with respect to the sub-pixels in the optical fiber cable constituting the backlight unit. FIG. 6 is an explanatory view showing an optical fiber cable constituting the backlight unit of the color liquid crystal display device, particularly its reflecting means, and FIG. 6 (a) is a plan view showing a state seen from the color liquid crystal shutter side. FIG. 6B is a cross-sectional view showing a state in which the optical fiber cable is cut along the axial direction and viewed from the radial direction, and FIG. 6C is a state viewed from the side opposite to the color liquid crystal shutter. FIG. 6D is a cross-sectional view showing a state in which the optical fiber cable is cut along the radial direction and viewed from the axial direction. FIG. 7 is one of explanatory views showing a state in which light guided along the axial direction of the optical fiber cable is reflected by the reflecting means and passes through the light diffusing structure, in the radial direction of the optical fiber cable. It is the schematic which shows the state where light is not diffusing seeing from. FIG. 8 is one of explanatory views showing a state in which light guided along the axial direction of the optical fiber cable is reflected by the reflecting means and passes through the light diffusion structure. It is the schematic which shows the state which light diffused seeing from. FIG. 9 is one of explanatory views showing a state in which light guided along the axial direction of the optical fiber cable is reflected by the reflecting means and passes through the light diffusion structure, and is emitted to the same sub-pixel. It is the schematic which shows that the light to be in a continuous state. FIG. 10 is a schematic diagram for explaining a different embodiment in which an optical waveguide is used instead of an optical fiber cable in a backlight unit.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows a simplified configuration of a color liquid crystal display device 1 in which the present invention is used. The color liquid crystal display device 1 includes a color liquid crystal shutter (also referred to as a color liquid crystal panel) 2 and the color liquid crystal. A drive control circuit board on which a backlight unit 3 disposed on the rear (rear) side of the shutter 2 and a drive control circuit for performing display drive control of these color liquid crystal shutters 2 and light emission control of the backlight unit 3 are mounted. (Not shown).

  The color liquid crystal shutter 2 has translucency, and as shown in FIGS. 3 and 4, a front (front) side glass 6, between plate-like polarizing films 4, 5 arranged facing each other, The liquid crystal 7 and the rear glass 8 are at least layered, and the TFT array substrate 10 is provided at the boundary between the rear glass 8 and the liquid crystal 7, and the counter substrate 9 is provided at the boundary between the front glass 6 and the liquid crystal 7. Furthermore, a black matrix 11 is arranged on the counter substrate 9.

  The color liquid crystal shutter 2 having such a configuration has a plurality of pixels 13 regularly arranged as shown in FIG. 2 when the color liquid crystal shutter 2 is viewed from the output display surface 12 side as shown in FIG. have. Each pixel 13 includes a red sub-pixel R, a green sub-pixel G, and a blue sub-pixel B. These sub-pixels R, G, and B have predetermined longitudinal dimensions and lateral dimensions. The red sub-pixel R, the green sub-pixel G, and the blue sub-pixel B are arranged in this order along the short direction. For example, one unit of pixel 13 is configured as a part surrounded by a broken line in FIG.

  As shown in FIGS. 1, 3, and 4, the backlight unit 3 includes a red light emitting diode (LED) 14, a green light emitting diode 15, a blue light emitting diode 16, and an optical fiber for red light for guiding red light. The cable 17 is basically composed of a green light optical fiber cable 18 for guiding green light, a blue light optical fiber cable 19 for guiding blue light, and a light diffusion structure 20 having a relatively small thickness. Has been.

  Of these, the red-light optical fiber cable 17 in this embodiment, as shown in FIG. 1, has one end facing the red light-emitting diode 14 and proceeds from the one end along the axial direction. Are branched one by one and extend to the rear side of the color liquid crystal shutter 2. Further, in this embodiment, as shown in FIG. 1, the one side end of the green light optical fiber cable 18 faces the green light emitting diode 15, and the green light fiber cable 18 progresses along the axial direction from the one side end. Each of them is branched one by one and extends to the rear side of the color liquid crystal shutter 2. Further, in this embodiment, as shown in FIG. 1, the optical fiber cable 19 for blue light has one end facing the blue light emitting diode 16 and progressing along the axial direction from the one end. Each of them is branched one by one and extends to the rear side of the color liquid crystal shutter 2. The optical fiber cables 17, 18, 19 are arranged in a plane on the rear side of the color liquid crystal shutter 2. In addition, the method of branching each optical fiber cable 17, 18, and 19 is not limited to this, The structure branched to several at once may be sufficient.

  The extending direction (direction along the axial direction of the optical fiber cables 17, 18, 19) on the rear surface of the color liquid crystal shutter 2 of each optical fiber cable 17, 18, 19 is as shown in FIGS. The direction is the same as the direction in which the sub-pixels R, G, and B are arranged in each pixel 13.

  As shown in FIG. 6 (particularly, FIGS. 6B and 6D), the optical fiber cables 17, 18, and 19 are clads that cover the core 21 and the entire circumference of the peripheral surface of the core 21. 22. The core 21 and the clad 22 are both made of quartz glass or plastic having a very high transmittance for light, while the refractive index of the core 21 is higher than that of the clad 22. When the ratio is a numerical value of 1.42, the refractive index of the core 21 is a numerical value of 1.47. Accordingly, light can be propagated only in the core 21 by total reflection and refraction of the light in the core 21 of the optical fiber cables 17, 18, and 19.

  Furthermore, as shown in FIG. 6, the light guided from the light emitting diodes 14, 15, 16 along the axial direction of the optical fiber cables 17, 18, 19 is transmitted in the radial direction of the optical fiber cables 17, 18, 19. As a light reflecting means for reflecting in the direction along, the substantially conical slot 23 extending from the clad 22 to the core 21 on the side opposite to the color liquid crystal shutter 2 of the side surfaces of the optical fiber cables 17, 18, 19. It has a plurality. The angle of the tip of the slot 23 is 45 °, for example. However, the shape and processing dimensions of the slot 23 are appropriately determined according to the refraction characteristics required for the slot 23. Further, the position of the slot 23 is not limited to the side opposite to the color liquid crystal shutter 2 among the side surfaces of the optical fiber cables 17, 18, 19, and the color liquid crystal shutter among the side surfaces of the optical fiber cables 17, 18, 19. Two sides may be used.

  As shown in FIG. 5, the interval dimension L1 of the slot 23 in the same optical fiber cable 17, 18, 19 is such that one slot 23 is shorter than any one of the sub-pixels R, G, and B. When located within the direction width, the slot 23 adjacent to the slot 23 is also located within the width of the sub-pixel for the same color as the adjacent slot 23 among the sub-pixels R, G, B. Is set to a numerical value (pixel pitch L1).

  Accordingly, the position of the slot 23 of the optical fiber cable 17 for red light, the position of the slot 23 of the optical fiber cable 18 for green light, and the position of the slot 23 of the fiber cable 19 for blue light are arranged in parallel. Sub-pixels (the center of the sub-pixel R in the short direction and the center of the sub-pixel G in the short direction, the center of the sub-pixel G in the short direction and the center of the sub-pixel B in the short direction, and / or the sub-pixel B) Are shifted one by one by the same dimension as the dimension (subpixel pitch L2) between the center in the short direction of the subpixel R and the center in the short direction of the subpixel R, so that the optical fiber cable for red light 17 The slot 23 is always located within the width in the short direction, the slot 23 is always located within the width in the short direction of the sub-pixel G in the green light optical fiber cable 18, and further, in the optical fiber cable 19 for blue light Slot 2 in the width of sub-pixel B in the short direction There it is always possible to position so as to be located.

  2, 3, and 4, the red light guided from the red light emitting diode 14 along the axial direction of the optical fiber cable 17 for red light is color liquid crystal shutter through the groove 23. 2 is reflected toward the red sub-pixel R and appropriately passes through the polarizing film 5, the rear glass 8, the liquid crystal 7, the front glass 6 and the polarizing film 4 of the color liquid crystal shutter 2 under predetermined conditions. . Further, the green light guided from the green light emitting diode 15 along the axial direction of the green light optical fiber cable 18 is also reflected toward the green sub-pixel G in the color liquid crystal shutter 2 by the groove 23, The polarizing film 5, the rear glass 8, the liquid crystal 7, the front glass 6, and the polarizing film 4 of the liquid crystal shutter 2 are appropriately transmitted under predetermined conditions. Further, the blue light guided from the blue light emitting diode 16 along the axial direction of the blue light optical fiber cable 19 is also reflected by the groove 23 toward the blue sub-pixel B in the color liquid crystal shutter 2, The polarizing film 5, the rear glass 8, the liquid crystal 7, the front glass 6, and the polarizing film 4 of the liquid crystal shutter 2 are appropriately transmitted under predetermined conditions.

  Therefore, since the color liquid crystal shutter 2 does not require red, green, and blue color filters, attenuation of light transmittance in the color liquid crystal shutter 2 can be suppressed, and the backlight unit. Therefore, the power consumption of the backlight unit 3 can be reduced.

  As shown in FIGS. 3 and 4, the light diffusion structure 20 is interposed between the optical fiber cables 17, 18, 19 and the color liquid crystal shutter 2, and the optical fiber cables 17, 18, As shown in FIG. 7 and FIG. 8, for example, the light reflected by the nineteen slot 23 is several degrees such as 5 ° in the direction from 9 o'clock to 3 o'clock, and from 6 o'clock of the watch. In the 12 o'clock direction, it has an anisotropic light diffusion function capable of performing light refraction or light diffusion such that it is several tens of degrees such as 30 °.

  More specifically, the light diffusing structure 20 is a surface that intersects the direction in which light is incident from the optical fiber cables 17, 18, 19, and a region where incident light from the optical fiber cables 17, 18, 19 reaches. A high performance diffusing lens film (LSD) processed so as to have at least the above anisotropic light diffusion function is used.

  As a result, the light reflected by the groove 23 of the optical fiber cables 17, 18, 19 diffuses along the longitudinal direction of the sub-pixels R, G, B when passing through the light diffusion structure 20. However, since diffusion of light is suppressed in the short direction, a groove is formed between the light guide plate and the light guide plate on the inner surface of the groove as in conventional color liquid crystal display devices. It is possible to omit a configuration in which a member such as a metal foil film having light shielding properties or the like is disposed.

  Further, as shown in FIG. 9, the light emitted from the adjacent groove holes 23 of the same optical fiber cables 17, 18, 19 is transmitted through the light diffusion structure 20, so that the sub-pixels R, G, B Since it diffuses in a substantially fan shape along the longitudinal direction, it can be continued, and since it is emitted from the plurality of slots 23, it is possible to prevent light from being scattered.

  The light diffusing structure 20 is light having a degree of several degrees such as 5 ° in the time from 9 o'clock to 3 o'clock, and several tens of degrees such as 30 ° in the direction from 6 o'clock to 12 o'clock. As long as it has an anisotropic light diffusion function capable of performing refraction or light diffusion, it is not limited to a high-performance diffusion lens film, for example, using a lenticular lens array in which a plurality of convex semi-cylindrical lenses are arranged. Also good.

  Further, in order to guide the light from each light emitting diode 14, 15, 16 to the back side of the color liquid crystal shutter 2, the optical fiber cables 17, 18, 19 are extended to the back side of the color liquid crystal shutter 2. It is not limited to.

  As shown in FIG. 10, the surface of the single-plate clad 22 having a relatively thin thickness and a relatively low light refractive index is opened to the color liquid crystal shutter 2 side on the surface on the color liquid crystal shutter 2 side. In addition, a linear recess 25 extending along the arrangement direction of the sub-pixels R, G, and B is formed, and a rectangular parallelepiped core 21a for red light, a rectangular core 21b for green light, Alternatively, a rectangular parallelepiped core 21c for blue light may be inserted in the order of arrangement of the sub-pixels R, G, and B in one pixel 13, and the optical waveguide 24 configured by filling these depressions may be used.

  Further, in this optical waveguide 24, a rectangular parallelepiped core 21a for red light is formed in a substantially triangular prism shape as viewed from the short side of the core 21a so as to be a light reflecting means like the slot 23. A plurality of slits 26 that are cut out are formed, and a plurality of slits 26 that are cut out in a substantially triangular prism shape when viewed from the short side of the core 21b are formed with respect to a rectangular parallelepiped core 21b that is used for green light. A plurality of slits 26 that are cut out in a substantially triangular prism shape when viewed from the short side of the core 21c are formed on a rectangular parallelepiped core 21c for light. The slits 26 are formed so as to extend along the short direction of the cores 21a, 21b, and 21c and have the same spacing as the pixel pitch L1.

  As a result, the slits 26 are shifted at the same interval as the sub-pixel pitch L2 between the adjacent red light core 21a and the green light core 21b, so that the adjacent green light core 21b and blue light core 21c. And the slit 26 is shifted at the same interval as the sub-pixel pitch L2, and the slit 26 is shifted at the same interval as the sub-pixel pitch L2 between the adjacent blue light core 21c and the red light core 21a. By doing, the same effect as the case where the optical fiber cables 17, 18, and 19 which have the slot 23 are used can be acquired.

  The present invention is a color liquid crystal display device used in equipment and devices that require display of all color still images and moving images, such as televisions, personal computers, mobile phones, etc., and can be used for those in which a color filter is omitted. Is possible.

DESCRIPTION OF SYMBOLS 1 Color liquid crystal display device 2 Color liquid crystal shutter 3 Backlight unit 4 Polarizing film 5 Polarizing film 6 Front side glass 7 Liquid crystal 8 Rear side glass 9 Opposite substrate 10 TFT array substrate 11 Black matrix 12 Output display surface 13 Pixel R Sub pixel for red G Sub-pixel for green B Sub-pixel for blue 14 Red light emitting diode (red light emitter)
15 Green light emitting diode (green light emitter)
16 Blue light emitting diode (blue light emitter)
17 Optical fiber cable for red light (light guide for red light)
18 Optical fiber cable for green light (green light guide)
19 Optical fiber cable for blue light (light guide for blue light)
20 Light diffusion structure 21 (21a, 21b, 21c) Core 22 Cladding 23 Groove hole (light reflecting means)
24 Optical waveguide 25 Dimple 26 Slit

Claims (5)

A long red light guide for guiding light using a red light source as a light source, a long green light guide for guiding light using a green light source as a light source, and a blue light emitter In a backlight unit of a color liquid crystal display device using a long blue light guide for guiding light as a light source,
The red light guide, the green light guide, and the blue light guide are red, green, and blue subpixels arranged in parallel to form one pixel of a color liquid crystal shutter. Are arranged in a planar shape along the arrangement direction of
The red light guide is formed with a plurality of light reflecting means for reflecting the red light guided along the longitudinal direction of the red light guide in the direction of the color liquid crystal shutter,
The light guide for green light is formed with a plurality of light reflecting means for reflecting the green light guided along the longitudinal direction of the light guide for green light toward the color liquid crystal shutter,
Furthermore, the light guide for blue light is formed with a plurality of light reflecting means for reflecting the blue light guided along the longitudinal direction of the light guide for blue light in the direction of the color liquid crystal shutter. With
The interval between the light reflecting means of the red light guide is the same as the interval between the red sub-pixels so that the light reflected by the light reflecting unit is incident on the red sub-pixel. ,
The interval between the light reflecting means of the green light guide is the same as the interval between the green sub-pixels so that the light reflected by the light reflecting unit is incident on the green sub-pixel. ,
Further, the distance between the light reflecting means of the blue light guide is the same as the distance between the blue sub-pixels so that the light reflected by the light reflecting means is incident on the blue sub-pixel. A backlight unit of a color liquid crystal display device characterized by its dimensions. A relatively thin light diffusion structure is interposed between the red light guide, the green light guide and the blue light guide and the color liquid crystal shutter;
In this light diffusion structure, light diffuses along the longitudinal direction of the red sub-pixel at a portion facing the light reflecting means of the light guide for red light, but the light is diffused in the short direction. Is provided at least in the anisotropic light diffusing means, and the light diffuses along the longitudinal direction of the green sub-pixel in the portion facing the light reflecting means of the light guide line for green light. At least anisotropic light diffusing means for suppressing light diffusion is provided, and light is diffused along the longitudinal direction of the blue sub-pixel at a portion facing the light reflecting means of the blue light guide line. 2. The backlight unit of a color liquid crystal display device according to claim 1, further comprising anisotropic light diffusing means for suppressing light diffusion in the hand direction.   The anisotropic diffusing unit is formed by using a high-performance diffusing lens film that has been processed at least in a region that intersects the direction in which light is incident from the light guide and that the incident light from the light guide reaches. The backlight unit of the color liquid crystal display device according to claim 2, wherein   The anisotropic diffusing means has a lenticular in which a plurality of convex semi-cylindrical lenses are arranged on a surface intersecting a direction in which light from the light guide is incident and where the incident light from the light guide reaches. The backlight unit of the color liquid crystal display device according to claim 2, wherein the backlight unit is formed by using a lens array. A long red light guide for guiding light using a red light source as a light source, a long green light guide for guiding light using a green light source as a light source, and a blue light emitter In a method for manufacturing a backlight unit of a color liquid crystal display device using a long blue light guide for guiding light as a light source,
The light guided along the longitudinal direction of the light guide is reflected by the light guide toward a color liquid crystal shutter including a plurality of pixels having red, green, and blue sub-pixels. A plurality of light reflecting means are formed, and the distance between the light reflecting means of the red light guide is the same as the distance between the red sub-pixels, and each light reflecting means of the green light guide And the same dimension as the distance between the green sub-pixels, and the distance between the light reflecting means of the blue light guide is the same as the distance between the blue sub-pixels,
The light guide is arranged along the surface of the color liquid crystal shutter so as to be regularly planar along the direction and order in which the sub-pixels are arranged, and the red light guide The reflecting means is positioned so that the light emitted from the light reflecting means is incident on the red sub-pixel, and the reflecting means of the green light guide is used as the light emitted from the light reflecting means. Positioning the light guide for blue light so that the light emitted from the light reflection means is incident on the blue subpixel; and ,
Light diffuses along the longitudinal direction of the sub-pixels between the red light guide, the green light guide, the blue light guide, and the color liquid crystal shutter. And a step of interposing a light diffusing structure provided with anisotropic light diffusing means for suppressing light diffusion in the direction.

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