JP2004226709A - Lightguide sheet and display lighting device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make light exit uniformly over the whole substrate without increasing the number of lightguides plate even if a display screen is increased in size. <P>SOLUTION: According to this invention, the lightguide sheet 1 is provided with a substrate 2, a tube-like lightguide plate 3 which is arranged on the surface of the substrate by patterning and guides the introduced light along the longitudinal direction when the light is introduced from an end part 5, and a plurality of light exit ports 6 that is located at different positions on the surface of the lightguide plate 3 and makes the light guided by the lightguide plate 3 exit from the inside to the outside of the lightguide plate 3 so that the light intensity becomes almost constant over the whole surface of the substrate 2. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a light guide sheet and a display lighting device using the same, and more particularly, to a light guide sheet that emits light emitted from a light source so that the light intensity over the entire surface of the sheet is substantially constant, and the light guide sheet. The present invention relates to a display illuminating device for uniformly illuminating a display screen by using a display.
[0002]
[Prior art]
2. Description of the Related Art Among displays having a built-in lighting device, a liquid crystal display (LCD) is remarkably popular, and illumination light from a light source (backlight or edge light) for generating display light is transmitted to a display screen. Of the type provided with a light guide sheet for making the brightness and the irradiation direction uniform at the same time is also remarkably widespread.
[0003]
There are various types of display lighting devices that illuminate such displays. One is a display illumination device of a type that illuminates the display screen directly from the back of the display screen (the side opposite to the observer) (hereinafter, referred to as “backlight type”). In addition, a display lighting device (hereinafter, referred to as a “light-emitting device”) that illuminates a display screen after passing illumination light from a light source disposed outside (eg, a side surface of) the display screen through a light guide sheet disposed on the back of the display screen. Edge light method ”).
[0004]
For the liquid crystal display, an edge light method is often used, and a substrate made of a translucent material, a linear light source made of a cold cathode tube or the like provided at a side end of the substrate, and a lower surface of the substrate and a light source. A typical example is a light reflection film disposed so as to cover the light guide sheet, and a light guide sheet including a light diffusion film and a lens sheet disposed on the upper surface of the substrate serving as a light exit surface.
[0005]
In order to improve the unevenness of the amount of emitted light due to the distance from the light source, measures have been taken such as printing a dot-like pattern made of light-diffusing ink on the back side of the substrate so that it becomes larger as the distance from the light source increases. Have been.
[0006]
The light diffusion film is arranged mainly to diffuse the light uniformly and obscure the dot pattern printed on the back surface of the substrate, and the lens sheet efficiently directs the light emitted from the substrate in the front direction of the liquid crystal panel. One or two sheets are arranged on the upper surface of the light diffusion film or between the light diffusion film and the substrate to collect light.
[0007]
As the above-mentioned lens sheet, a lens sheet (prism sheet) in which a large number of triangular prism type unit lens portions are arranged in parallel in order to uniformly and isotropically diffuse radiated light within a desired angle range is used. This lens sheet is called BEF (Brightness Enhancement Film: trade name, manufactured by Sumitomo 3M).
[0008]
In addition, some methods for guiding light from a light source through an optical fiber have been applied to other light guide sheets in an edge light system or the like. The advantage of using an optical fiber is that the illumination light from the light source can be transmitted to the illumination target with low loss, and that the optical path from the light source to the illumination target can be bent. The flexibility is to be improved.
[0009]
Known documents relating to the light guide sheet using such an optical fiber will be described below.
[0010]
Patent Literature 1 discloses an illuminating device for illuminating a liquid crystal display from behind, which includes a micro-converging lens array and a micro-secondary light source disposed at the focal point of each micro-converging lens, and irradiates substantially parallel light. Optical fiber is applied.
[0011]
Patent Document 2 discloses a liquid crystal display display panel provided with pixels corresponding to the three primary colors of red, green, and blue, a backlight-type light source unit that illuminates the display panel with light transmitted from the back, and a pixel of the display panel. On the other hand, there is disclosed a display device for a full-color liquid crystal display, which is provided with wavelength selecting means for transmitting only primary colors corresponding to respective pixels. The backlight type light source unit is characterized in that the light emitting surface is divided into red, green and blue light emitting blocks corresponding to the pixels of the display panel.
[0012]
Patent Document 3 discloses an optical fiber backlight module for a color display. This consists of a light source, a plurality of side-emitting optical fibers that are connected to the light source, are arranged in parallel, transmit light emitted from the light source, emit light from the side, and form an optical fiber of the first layer, and a side-emitting optical fiber. A plurality of column isolation parts provided between adjacent columns are provided.
[0013]
In Patent Document 4, at least one LED, a plurality of optical fibers having an emitting end arranged substantially linearly and an incident end facing the LED, and a light for optically connecting the LED and the incident end of the optical fiber are disclosed. A light source device having a connecting means is disclosed.
[0014]
As exemplified above, each of the light guide sheets to which an optical fiber is applied as a light guide is configured to receive a light beam from one end and emit the light as illumination light toward an illumination target. .
[0015]
[Patent Document 1]
JP-A-6-222362
[0016]
[Patent Document 2]
JP-A-9-252825
[0017]
[Patent Document 3]
JP-A-10-288782
[0018]
[Patent Document 4]
JP 2000-231816 A
[0019]
[Problems to be solved by the invention]
However, such a conventional light guide sheet and a display lighting device using the same have the following problems.
[0020]
That is, in the case of the display lighting device using the light guide sheet as described above, in order to uniformly illuminate the entire display screen, as the size of the display screen increases, more optical fibers are required. Therefore, not only does the cost of the light guide sheet increase, but also the size of the light guide sheet increases according to the length and the number of optical fibers from the incident side to the exit side. Further, the display lighting device using such a light guide sheet also has a problem that the thickness and the weight also increase as the size of the display screen increases.
[0021]
The present invention has been made in view of such circumstances, and a first object of the present invention is to substantially uniformly emit light over the entire substrate without increasing the number of optical fibers even when the size of the display screen is increased. An object of the present invention is to provide a light guide sheet that can be emitted.
[0022]
The second object is to use such a light guide sheet to uniformly illuminate the entire display screen without increasing the thickness and weight of the display screen even if the size of the display screen increases. It is an object of the present invention to provide a display lighting device capable of performing the above-mentioned operations.
[0023]
[Means for Solving the Problems]
In order to achieve the above object, the present invention takes the following measures.
[0024]
That is, in order to achieve the first object, the light guide sheet according to the first aspect of the present invention is arranged by patterning a substrate and a surface of the substrate, and is introduced when light is introduced from an end. A tubular light guide that guides light along the length direction, and a light guide that is arranged at different locations on the surface of the light guide. A plurality of light exit ports for emitting light from the inside of the light guide to the outside.
[0025]
Therefore, in the light guide sheet according to the first aspect of the present invention, by taking the above measures, light is introduced from an external light source such as an edge light, and the introduced light has a light intensity over the entire surface of the substrate. Injection can be made to be almost constant. Further, even when the area of the substrate is increased, for example, it is not necessary to increase the number of light guides using optical fibers.
[0026]
According to a second aspect of the present invention, in order to achieve the first object, in the light guide sheet according to the first aspect of the present invention, the light guide is arranged on the surface of the substrate so as to consist of a plurality of continuous linear portions. are doing.
[0027]
Therefore, in the light guide sheet according to the second aspect of the present invention, by taking the above measures, the light guide can be arranged evenly over the entire surface of the substrate. As a result, light introduced from an external light source such as an edge light can be emitted so that the light intensity over the entire surface of the substrate is substantially constant.
[0028]
According to a third aspect of the present invention, in order to achieve the first object, in the light guide sheet of the first aspect of the present invention, the light guide is disposed so as to include at least a curved portion on the surface of the substrate. .
[0029]
Therefore, in the light guide sheet according to the third aspect of the present invention, by taking the above measures, the light guide can be freely arranged over the entire surface of the substrate. As a result, light introduced from an external light source such as an edge light can be emitted so that the light intensity over the entire surface of the substrate is substantially constant.
[0030]
According to a fourth aspect of the present invention, in order to achieve the first object, in the light guide sheet of the first aspect of the present invention, the light exit port is moved from the end where light is introduced toward the other end. The light guides are arranged such that the arrangement density or the light exit area ratio on the surface of the light guide is increased.
[0031]
Therefore, in the light guide sheet according to the fourth aspect of the present invention, by taking the above measures, the light introduced from the end can be emitted so that the light intensity over the entire surface of the substrate becomes substantially constant. it can.
[0032]
According to a fifth aspect of the present invention, in order to achieve the first object, in the light guide sheet according to the first aspect of the present invention, light is introduced into a cross-sectional area in a cross section substantially orthogonal to the length direction of the light guide. The light exits are arranged at substantially equal pitches on the surface of the light guide, while decreasing from the end to the other end.
[0033]
Therefore, in the light guide sheet according to the fifth aspect of the present invention, by taking the above measures, the light introduced from the end can be emitted so that the light intensity over the entire surface of the substrate becomes substantially constant. it can.
[0034]
According to a sixth aspect of the present invention, in order to achieve the first object, in the light guide sheet of the first aspect of the present invention, light is introduced into a cross-sectional area in a cross section substantially orthogonal to the length direction of the light guide. Each light emission is increased so as to increase from the end where the light is introduced to the other end, and to increase the distance between the adjacent light emission ports from the end where the light is introduced to the other end. There is an exit.
[0035]
Therefore, in the light guide sheet according to the sixth aspect of the present invention, by taking the above measures, the light introduced from the end can be emitted so that the light intensity over the entire surface of the substrate becomes substantially constant. it can.
[0036]
According to a seventh aspect of the present invention, in order to achieve the first object, in the light guide sheet of the first aspect of the present invention, the light guide is disposed on the surface of the substrate so as to consist of a plurality of continuous linear portions. The first arrangement pattern, the second arrangement pattern arranged so as to include at least the curved portion on the surface of the substrate, and the arrangement pattern on the surface of the substrate from the end where light is introduced toward the other end. The third arrangement pattern arranged to increase the density and the cross-sectional area in a cross section substantially orthogonal to the length direction of the light guide become smaller from the end where light is introduced toward the other end. Any one of the fourth arrangement pattern arranged as described above and the fifth arrangement pattern arranged so that the cross-sectional area increases from the end where light is introduced toward the other end. Combining the above arrangement patterns It is arranged by the combined arrangement pattern.
[0037]
Therefore, in the light guide sheet according to the seventh aspect of the present invention, by combining various arrangement patterns, light introduced from the end can be emitted so that the light intensity over the entire surface of the substrate becomes substantially constant. .
[0038]
According to an eighth aspect of the present invention, in order to achieve the first object, in the light guide sheet of the first aspect of the present invention, each light exit port has substantially the same optical characteristics.
[0039]
Therefore, in the light guide sheet according to the eighth aspect of the present invention, it is sufficient to provide the light guide with the same optical characteristics in the light guide, so that the light guide sheet can be easily manufactured.
[0040]
According to a ninth aspect of the present invention, in order to achieve the first object, in the light guide sheet according to the first aspect of the present invention, each of the light exits has an arrangement density or a light exit area ratio in the light guide. Are substantially the same, and the shapes and dimensions are substantially the same.
[0041]
Therefore, in the light guide sheet according to the ninth aspect of the present invention, since the light guides having the same optical characteristics may be provided in the light guide by taking the above-described means, the light guide sheet can be easily manufactured. it can.
[0042]
According to a tenth aspect of the present invention, in order to achieve the first object, in the light guide sheet according to the first aspect of the present invention, the shape and dimensions of each light exit and the arrangement density or the light exits arranged in the light guide. By adjusting the area ratio, the shape and dimensions of the light guide, and the arrangement pattern on the substrate, the light intensity is made substantially constant.
[0043]
Therefore, in the light guide sheet according to the tenth aspect of the present invention, by taking the above measures, the light introduced from the end can be emitted so that the light intensity over the entire surface of the substrate becomes substantially constant. it can.
[0044]
In order to achieve the second object, a display lighting device according to an eleventh aspect of the present invention provides a light guide sheet according to any one of the first to tenth aspects and a light guide from an end of the light guide. A light source that supplies light to be introduced into the body, and illuminates the display by emitting light emitted from the light emission port toward the display to be illuminated.
[0045]
Therefore, in the display illuminating device according to the eleventh aspect of the present invention, by taking the above measures, it is possible to uniformly illuminate the entire screen of the display.
[0046]
According to a twelfth aspect of the present invention, there is provided a display lighting device, wherein the light guide sheet according to any one of the first to tenth aspects and a light guide from an end of the light guide are provided to achieve the second object. A light source that supplies light to be introduced into the body; the light emitted from the light exit port is emitted from the back of the display to be illuminated, thereby illuminating the display from the back.
[0047]
Therefore, in the display illuminating device according to the twelfth aspect of the present invention, by taking the above measures, it can be used as a backlight capable of uniformly illuminating the entire screen of the display.
[0048]
According to a thirteenth aspect of the present invention, in order to achieve the second object, in the display illuminating device according to the eleventh or twelfth aspect, the light emitted from each light exit port constitutes a display. Each light exit port is arranged so as to illuminate each pixel.
[0049]
Therefore, in the display lighting device according to the thirteenth aspect, the display performance of the display can be improved by taking the above-described means.
[0050]
According to a fourteenth aspect of the present invention, in order to achieve the second object, the light guide sheet according to the seventh aspect of the present invention supplies light introduced from the end of the light guide into the light guide. A light source, and illuminating the display by emitting light emitted from the light exit port toward the display to be illuminated, wherein the display is configured from three types of color sets RGB. A plurality of pixels, and the light exits are arranged so that light emitted from each light exit illuminates each pixel.
[0051]
Therefore, in the display lighting device according to the fourteenth aspect of the present invention, by taking the above-described means, it is possible to perform full-color display without using a color filter.
[0052]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0053]
(First Embodiment)
A first embodiment of the present invention will be described with reference to FIGS.
[0054]
FIG. 1 is a plan view illustrating a configuration example of the light guide sheet according to the first embodiment.
[0055]
That is, in the light guide sheet 1 according to the present embodiment, the tubular light guide 3 is patterned and arranged on the surface of the substrate 2. The light guide 3 is made of, for example, an optical fiber and has a uniform shape and size along the length direction. That is, the shape and dimensions of the cross section orthogonal to the length direction are constant over the length direction. Such a light guide 3 may be arranged by being placed on the surface of the substrate 2 as shown in FIG. 2A, or may be embedded in the surface of the substrate 2 as shown in FIG. 2B. It may be arranged in such a manner. The shape of a cross section orthogonal to the length direction is also a rectangular shape as shown in FIG. 3A, a semicircular shape as shown in FIG. 3B, a trapezoidal shape as shown in FIG. There are various possibilities, and the shape is not limited. Such a light guide 3 introduces the incident light emitted from the light source 4 through the incident light introduction port 5 and guides the introduced light to the other end 7 along the length direction.
[0056]
Generally, when the size of the light guide 3 is close to the wavelength of the light passing therethrough, only a specific optical mode can pass through the light guide 3, so that the light source 4 that emits light with a narrow bandwidth is used. Although necessary, the type of the light source 4 does not matter when the size of the light guide 3 is larger than the wavelength by several times or more. Therefore, there are various types of light sources 4 to be used, and selection is made according to the application. For communication, a high-quality light source such as a laser is preferable, and a light-emitting diode is often used. However, as in this embodiment, when illumination is the main application, white light is preferable. .
[0057]
On the surface of the light guide 3, a plurality of light exits 6 for emitting the incident light introduced from the incident light inlet 5 from the inside of the light guide 3 to the outside are provided at different places. When the incident light is introduced into the light guide 3, the incident light passes through the light guide 3 while repeating scattering and refraction in the light guide 3 as shown in FIG. ing.
[0058]
In the present embodiment, the light intensity on the surface of the light guide sheet 1 illuminated by the light emitted from each light exit 6 is adjusted by adjusting the shape, dimensions, arrangement pitch, and the like of the light exits 6. It is made to be almost constant throughout. For example, when adjusting the amount of light emitted from the light exit 6 by scattering, the intensity of the emitted light is controlled by adjusting the size of the light exit 6. On the other hand, when adjusting the amount of light emitted from the light exit port 6 by diffraction, the intensity of emitted light is controlled by adjusting the diffraction efficiency.
[0059]
The arrangement pattern of the light exit ports 6 as shown in FIG. 1 is an example, and the light guides 3 are arranged on the surface of the substrate 2 in a folded manner at a constant interval t, and the light of uniform shape and size is further provided. The emission ports 6 are arranged such that the arrangement density increases from the incident light introduction port 5 toward the other end 7 side, that is, the arrangement pitch p decreases.
[0060]
FIG. 5 shows another example, in which the light guide 3 is disposed in a folded manner at a constant interval t on the surface of the substrate 2, and the light exit 6 is further connected to the incident light inlet 5 from the other end. The arrangement is such that the area ratio of the light exit port becomes higher toward the portion 7, that is, the aperture d becomes larger while the arrangement pitch p is kept constant.
[0061]
Next, the operation of the light guide sheet according to the present embodiment configured as described above will be described.
[0062]
That is, in the light guide sheet 1 according to the present embodiment, the incident light emitted from the light source 4 is introduced from the incident light inlet 5 into the light guide 3. The introduced incident light is guided inside the light guide 3 to the other end 7 along the length direction.
[0063]
The incident light thus introduced into the inside of the light guide 3 is emitted from the plurality of light exit ports 6 provided in the light guide 3 to the outside of the light guide 3. As shown in FIG. 7, light guides 3 are disposed in a folded shape at a constant interval t on the surface of the substrate 2 and a plurality of light exits 6 having a uniform shape and dimensions are further connected to the incident light inlet 5. When the light is emitted from the light exit 6 on the incident light introduction port 5 side, the light intensity exits from the light exit 6 on the other end 7. Light intensity. Therefore, the light intensity on the surface of the light guide sheet 1 is not uniform.
[0064]
However, in the light guide sheet 1 according to the present embodiment, the light intensity of the light emitted from each light exit 6 on the sheet surface is adjusted by adjusting the shape size and arrangement pitch p of each light exit 6. Is approximately constant over the entire surface.
[0065]
That is, as shown in FIG. 1, for example, a light exit 6 having a uniform shape and size is provided in the light guide 3 which is folded over the surface of the substrate 2 at a constant interval t. Are arranged so that the arrangement density becomes higher from the other end 7 side, that is, the arrangement pitch p becomes shorter.
[0066]
With such a configuration, the total area of the light emission port 6 on the other end 7 side is increased, and the intensity of light emitted from the light emission port 6 on the other end 7 side is increased. The light intensity is made uniform over the entire surface of the substrate 2 of the sheet 1.
[0067]
Alternatively, as shown in FIG. 5, for example, the light guide 3 may be folded from the incident light inlet 5 to the other end 7 side on the surface of the light guide 3 that is folded back at a constant interval t on the surface of the substrate 2. Therefore, the same effect can be obtained by arranging so that the light emission port area ratio is increased, that is, the aperture d is increased while the arrangement pitch p is kept constant.
[0068]
Alternatively, as shown in the cross-sectional view of FIG. 6, for example, the thickness of the light guide 3 disposed on the surface of the substrate 2 and having the light exit ports 6 disposed at the same arrangement pitch p is increased from the incident light entrance port 5 side. You may make it gradually thin toward the other end part 7 side. With such a configuration, the area ratio of the light exit port to the unit volume of the light guide 3 at the position where the light exit port 6 is disposed increases as going from the incident light entrance port 5 to the other end 7 side. Even so, the same effect can be obtained.
[0069]
With the above-described configuration, the light intensity emitted from the light emission port 6 on the other end 7 side is increased, and thus the light intensity on the entire surface of the substrate 2 of the light guide sheet 1 is made uniform. be able to.
[0070]
Note that a configuration in which the arrangement density of the light exit ports 6 and the area ratio of the light exit ports increase from the incident light inlet port 5 toward the other end 7 side as shown in FIGS. The present invention is not limited to the case where the body 3 is arranged in a folded shape. As shown in FIGS. 8 and 9, the light guide 3 may be arranged in a substantially spiral shape composed of a plurality of continuous linear portions. The present invention can also be applied to the light guide sheet 10 described above.
[0071]
FIG. 8 shows that the light guide 3 arranged in a substantially spiral shape at a constant interval t on the surface of the substrate 2 is provided with a light exit 6 having a uniform shape and dimensions from the incident light inlet 5 to the other end 7. The configuration of the light guide sheet 10 arranged such that the arrangement density becomes higher toward the side, that is, the arrangement pitch p becomes shorter, is shown.
[0072]
FIG. 9 shows that the light guide 3 arranged in a substantially spiral shape at a constant interval t on the surface of the substrate 2 is provided with a light exit 6 having a uniform shape and a size from the incident light inlet 5 to the other end. The configuration of the light guide sheet 10 is arranged such that the area ratio of the light exit opening increases toward the part 7, that is, the aperture d increases with the arrangement pitch p kept constant.
[0073]
Further, a configuration in which the arrangement density of the light emission ports 6 and the area ratio of the light emission ports increase from the incident light introduction port 5 to the other end 7 side is shown in FIGS. 1 and 5 and FIGS. As shown in the figure, the present invention is not limited to the case where the light guide 3 is arranged so as to be composed of a plurality of continuous linear portions. As shown in FIGS. The present invention can also be applied to the light guide sheet 11 arranged. Alternatively, although not shown, the same is true even if all of the light guides 3 are arranged in a curved shape.
[0074]
FIG. 10 shows a light guide 3 arranged in a substantially spiral shape on the surface of the substrate 2 by arranging the outer peripheral side of the substrate 2 in a plurality of continuous straight lines and the inner peripheral side in a curved shape. The configuration of the light guide sheet 11 in which the light exit port 6 having the dimension is arranged so that the arrangement density becomes higher from the incident light inlet port 5 toward the other end 7 side, that is, the arrangement pitch p becomes shorter. Is shown.
[0075]
FIG. 11 shows one light guide 3 arranged in a substantially spiral shape on the surface of the substrate 2 by arranging the outer periphery of the substrate 2 in a plurality of continuous straight lines and the inner periphery in a curved shape. The diameter d of the light emission port 6 having the same shape and size increases so that the area ratio of the light emission port increases from the incident light introduction port 5 toward the other end 7 side, that is, the arrangement pitch p is kept constant. The configuration of the light guide sheet 10 arranged as described above is shown.
[0076]
As described above, in the light guide sheet according to the present embodiment, the emitted light can be obtained by the above-described operation such that the light intensity becomes substantially uniform over the entire surface of the substrate 2.
[0077]
In addition, even if the size of the substrate 2 is increased, it can be realized without increasing the number of the light guides 3. That is, for example, when an optical fiber is used as the light guide 3, and when the size of the substrate 2 is increased, it is possible to cope with the problem by simply increasing the length of the optical fiber without increasing the number of optical fibers. Therefore, even when the size of the substrate 2 is increased, both the thickness and the weight do not increase so much, and substantially uniform light intensity over the entire surface of the substrate 2 can be realized.
[0078]
Therefore, when such a light guide sheet is used as a display illumination device (including a backlight) for illuminating a display, it is possible to illuminate the display screen of the display almost uniformly. Further, even when a large display is illuminated, it is possible to cope with the display without increasing the thickness and weight of the display.
[0079]
(Second embodiment)
A second embodiment of the present invention will be described with reference to FIGS.
[0080]
12 to 15 are plan views showing a configuration example of the light guide sheet according to the second embodiment. The same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. Only the part will be described.
[0081]
That is, the light guide sheet 12 according to the present embodiment has a comb as shown in FIGS. 12 to 15 in place of the one-stroke light guide 3 as shown in FIGS. The point is that the toothed light guide 13 is arranged on the surface of the substrate 2.
[0082]
As shown in FIG. 12, the light guide 13 includes a main portion 13a having an incident light inlet 5 at one end for introducing incident light generated from the light source 4 into the light guide 13, and a main portion. 13a, and a plurality of comb-tooth portions 13b of the same shape and dimensions branched from 13a. The respective comb teeth 13b are arranged in parallel and at the same pitch s. In the case where the number of comb teeth 13b is extremely large, as shown in FIG. 13, the comb teeth 13b may be arranged so that the interval between adjacent comb teeth 13b is random. The incident light introduced into the main part 13a through the incident light inlet 5 is guided from the main part 13a to each comb tooth 13b. Further, the comb teeth 13b do not necessarily have to be linear, but may have a waveform as shown in FIG.
[0083]
Further, each comb tooth portion 13b is provided with a light exit port 6 on its surface so that the arrangement density increases as the distance from the incident light entrance port 5 increases. The arrangement density does not necessarily have to increase continuously, but may increase intermittently. Alternatively, although not shown, the diameter d of the light exit ports 6 arranged at the same arrangement pitch p is increased as the distance from the incident light inlet port 5 is increased, so that the area ratio of the light exit ports is increased, In addition, while the light exit ports 6 are arranged at the same pitch, the thickness of the comb-tooth portion 13b decreases as the distance from the incident light entrance port 5 increases, so that the unit of the light guide 3 at the place where the light exit port 6 is disposed The ratio of the light exit area to the volume may be increased.
[0084]
Next, the operation of the light guide sheet according to the present embodiment configured as described above will be described.
[0085]
That is, in the light guide sheet 12 according to the present embodiment, the incident light emitted from the light source 4 is introduced into the main part 13 a of the light guide 13 from the incident light inlet 5. The introduced incident light is successively guided to a plurality of comb teeth portions 13b branched from the main portion 13a while being guided to the other end portion 7 side of the main portion 13a.
[0086]
The incident light introduced into each of the comb teeth 13b in this manner is emitted to the outside of the light guide 13 from the plurality of light emission ports 6 provided in the comb teeth 13b.
[0087]
Also in the light guide sheet 12 according to the present embodiment, similarly to the first embodiment, by adjusting the shape size and the arrangement pitch p of each light exit port 6, the light exit from each light exit port 6 is adjusted. The light intensity on the surface of the light guide sheet 12 illuminated by light is made substantially constant over the entire surface.
[0088]
That is, the arrangement pitch p of the light exit ports 6 having the same shape and size is reduced as the distance from the incident light entrance port 5 increases, or the diameter d of the light exit ports 6 arranged at the same pitch is set far from the incident light entrance port 5. The light emitting ports 6 are arranged to be as large as possible or arranged at the same pitch at the same shape and size, while the thickness of the comb teeth 13b is reduced as the distance from the incident light introducing port 5 increases.
[0089]
With such a configuration, the light intensity of the light emitted from the light exit port 6 is increased as the distance from the incident light inlet port 5 increases, and the light intensity on the entire surface of the substrate 2 of the light guide sheet 1 is made uniform. Can be
[0090]
The configuration of the light guide sheet 12 using the comb-shaped light guide 13 is limited to a light guide 13 including a main portion 13a and a comb-shaped portion 13b as shown in FIGS. Instead, as shown in FIG. 15, the light guide 13 may be a comb-like member formed by branching. Even in the light guide 13 having such a configuration, the arrangement pitch p of the light exit ports 6 having the same shape and size is reduced as the distance from the incident light entrance port 5 increases, or the light exit ports 6 arranged at equal pitches are arranged. Is increased as the distance from the incident light introduction port 5 increases, or the light exit ports 6 are arranged at the same pitch with the same shape and size, while the thickness of the comb teeth 13b decreases as the distance from the incident light introduction port 5 increases. Has been to be.
[0091]
As described above, in the light guide sheet 12 according to the present embodiment, emitted light can be obtained by the above-described operation such that the light intensity becomes substantially uniform over the entire surface of the substrate 2.
[0092]
Therefore, when such a light guide sheet 12 is used as a display illumination device (including a backlight) for illuminating a display, it is possible to illuminate the display screen of the display substantially uniformly. Further, even when a large display is illuminated, it is possible to cope with the display without increasing the thickness and weight of the display.
[0093]
(Third embodiment)
A third embodiment of the present invention will be described with reference to FIG.
[0094]
FIG. 16 is a plan view showing a configuration example of the light guide sheet according to the third embodiment. The same parts as those in FIG. 12 are denoted by the same reference numerals, and the description thereof will be omitted. State.
[0095]
That is, similarly to the light guide sheet of the second embodiment, the light guide sheet according to the present embodiment also has an incident light introduction port 5 for introducing the incident light generated from the light source 4 inside at one end. The light guide 14 includes a main portion 14a and a plurality of comb-shaped portions 14b having the same shape and dimensions branched from the main portion 14a. The difference from the configuration of the light guide sheet 12 shown in FIG. 12 is that the width of each comb-tooth portion 14 b increases as the distance from the incident light inlet 5 increases. Each comb tooth portion 14b has a light exit port 6 on its surface so that the arrangement pitch p becomes narrower as the distance from the incident light entrance port 5 increases.
[0096]
When the width of the comb teeth 14b increases as the distance from the incident light inlet 5 increases, the incident light introduced into the comb teeth 14b is diffused as the distance from the incident light inlet 5 increases, and the light intensity decreases. However, in the present embodiment, the light emitting port 6 is provided with a narrower arrangement pitch p so that more light can be emitted even when the light intensity is weakened. Thus, the light exit port 6 is obtained so that the light intensity becomes substantially uniform over the entire surface of the substrate 2.
[0097]
Next, the operation of the light guide sheet according to the present embodiment configured as described above will be described.
[0098]
That is, in the light guide sheet according to the present embodiment, the incident light emitted from the light source 4 is introduced into the main part 14 a of the light guide 3 from the incident light inlet 5. The introduced incident light is successively guided to a plurality of comb teeth portions 14b branched from the main portion 14a while being guided to the other end portion 7 side of the main portion 14a.
[0099]
The incident light thus introduced into each of the comb teeth 14b is emitted to the outside of the light guide 14 from the plurality of light emission ports 6 provided in the comb teeth 14b.
[0100]
In the present embodiment, the width of the comb teeth portion 14b increases as the distance from the incident light inlet 5 increases. Therefore, the incident light introduced into the comb teeth portion 14b is diffused as the distance from the incident light introduction port 5 increases, and the light intensity becomes weak. On the other hand, in the present embodiment, the arrangement pitch p is narrowed as the distance from the incident light inlet 5 is increased so that more light can be emitted even when the light intensity is weakened. Since it is provided, a uniform light intensity can be obtained on the entire surface of the substrate 2 by the light emitted from the light emission port 6.
[0101]
As described above, in the light guide sheet according to the present embodiment, the emitted light can be obtained by the above-described operation such that the light intensity becomes substantially uniform over the entire surface of the substrate 2.
[0102]
Therefore, when such a light guide sheet is used as a display illumination device (including a backlight) for illuminating a display, the display screen of the display can be illuminated almost uniformly. Further, even when a large display is illuminated, it is possible to cope with the display without increasing the thickness and weight of the display.
[0103]
(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to FIG.
[0104]
FIG. 17 is a plan view showing a configuration example of the light guide sheet according to the fourth embodiment. The same parts as those in FIG. 12 are denoted by the same reference numerals, and the description thereof will be omitted. State.
[0105]
That is, similarly to the light guide sheet of the second embodiment, the light guide sheet according to the present embodiment also has an incident light introduction port 5 for introducing the incident light generated from the light source 4 inside at one end. The light guide 15 includes a main portion 15a and a plurality of comb-shaped portions 15b having the same shape and dimensions branched from the main portion 15a. The difference from the configuration of the light guide sheet shown in FIG. 12 is that the width of each comb tooth portion 15 b is reduced as the distance from the incident light inlet 5 increases. Each comb tooth portion 15b is provided on its surface with a plurality of light exit ports 6 having the same arrangement pitch and the same shape and size.
[0106]
Normally, when a plurality of light exit ports 6 having the same shape and dimensions are arranged at the same arrangement pitch, since incident light is emitted in order from the light exit port 6 side of the incident light entrance port 5, the incident light exit port 5 The emission light intensity decreases as the distance increases. However, in the present embodiment, the width of the comb teeth portion 15b is reduced as the distance from the incident light inlet 5 increases. As a result, the incident light introduced into the comb teeth portion 15b is condensed as the distance from the incident light inlet 5 increases, and the intensity of the emitted light does not decrease even when the distance from the incident light inlet 5 increases. The emission light intensity over the entire surface of the substrate 2 is made uniform.
[0107]
Next, the operation of the light guide sheet according to the present embodiment configured as described above will be described.
[0108]
That is, in the light guide sheet 1 according to the present embodiment, the incident light emitted from the light source 4 is introduced into the main part 15 a of the light guide 15 from the incident light inlet 5. The introduced incident light is successively guided to a plurality of comb teeth portions 15b branched from the main portion 15a while being guided to the other end portion 7 side of the main portion 15a.
[0109]
The incident light introduced into each of the comb teeth 15b in this manner is emitted to the outside of the light guide 15 from the plurality of light exit ports 6 provided at the same arrangement pitch p as the comb teeth 15b. You.
[0110]
In the present embodiment, the width of the comb teeth portion 15b becomes thinner as the distance from the incident light inlet 5 increases. Therefore, the incident light introduced into the comb teeth portion 15b is collected as the distance from the incident light inlet 5 increases. Thus, the intensity of the emitted light does not decrease even when the distance from the incident light inlet 5 is increased, and a uniform light intensity can be obtained on the entire surface of the substrate 2.
[0111]
As described above, in the light guide sheet according to the present embodiment, the emitted light can be obtained by the above-described operation such that the light intensity becomes substantially uniform over the entire surface of the substrate 2.
[0112]
Therefore, when such a light guide sheet is used as a display illumination device (including a backlight) for illuminating a display, the display screen of the display can be illuminated almost uniformly. Further, even when a large display is illuminated, it is possible to cope with the display without increasing the thickness and weight of the display.
[0113]
(Fifth embodiment)
A fifth embodiment of the present invention will be described with reference to FIG.
[0114]
FIG. 18 is a plan view showing a configuration example of the light guide sheet according to the fifth embodiment. The same parts as those in FIG. 12 are denoted by the same reference numerals, and the description thereof will be omitted. State.
[0115]
That is, the light guide sheet according to the present embodiment also has a main portion 16a having an incident light inlet 5 for introducing the incident light generated from the light source 4 at one end, and a branch from the main portion 16a. The light guide 16 includes a plurality of comb teeth. However, this light guide 16 has a configuration in which the light guide 14 of the third embodiment and the light guide 15 of the fourth embodiment are combined, and as shown in FIG. Comb portions 16b whose width becomes narrower as the distance from the inlet 5 is increased, and conversely, comb teeth 16c whose width increases as the distance from the incident light inlet 5 is alternately arranged. Is a point.
[0116]
Then, as described in the fourth embodiment, the light emitting ports 6 having the same arrangement pitch p and the same shape and dimensions are provided in the comb teeth 16b, and the comb teeth 16c are provided in the third embodiment as described in the fourth embodiment. As described above, the light exit port 6 is provided so that the arrangement pitch p becomes narrower as the distance from the incident light entrance port 5 increases.
[0117]
Even with such a configuration, emitted light can be obtained so that the light intensity becomes substantially uniform over the entire surface of the substrate 2.
[0118]
Therefore, when such a light guide sheet is used as a display illumination device (including a backlight) for illuminating a display, it is possible to illuminate the display screen of the display substantially uniformly. In addition, even when a large display is illuminated, it is possible to cope with the display without increasing the thickness and weight of the display.
[0119]
(Sixth embodiment)
A sixth embodiment of the present invention will be described with reference to FIGS.
[0120]
19 and 20 are plan views showing a configuration example of a light guide sheet according to the sixth embodiment. The same parts as those in FIG. 12 are denoted by the same reference numerals, and description thereof will be omitted. Only the part will be described.
[0121]
That is, the light guide sheet of the present invention is configured by appropriately combining the light guide arrangement methods described in the first to fifth embodiments.
[0122]
19 and 20 each show an example of the combination. FIG. 19 shows a light guide sheet in which two comb-shaped light guides 13 as shown in FIG. 12 are arranged to face each other. . Each of the light guides 13 has an incident light inlet 5a, 5b for introducing incident light from a unique light source 4a, 4b, respectively.
[0123]
FIG. 20 shows a light guide sheet formed by laminating two light guide sheets 1 each having a one-stroke light guide 3 as shown in FIG. Also in this case, each light guide 3 is provided with incident light introduction ports 5a and 5b for introducing incident light from a unique light source (not shown). Further, although not shown, for example, the light guide sheet may be configured by attaching three or more light guide sheets according to the first to fifth embodiments.
[0124]
Even with such a configuration, emitted light can be obtained so that the light intensity becomes substantially uniform over the entire surface of the substrate 2.
[0125]
Therefore, when such a light guide sheet is used as a display illumination device (including a backlight) for illuminating a display, it is possible to illuminate the display screen of the display substantially uniformly. In addition, even when a large display is illuminated, it is possible to cope with the display without increasing the thickness and weight of the display.
[0126]
Further, as shown in FIG. 20, by forming a light guide sheet having a laminated structure, it is possible to increase the formation density of the pattern of the light guide (and the arrangement density of the light emission ports 6) with only one substrate 2. Is difficult, it is possible to easily realize high density by superimposing the light guides arranged on different substrates 2.
[0127]
Of course, what is shown in FIG. 19 and FIG. 20 is an example of the light guide sheet according to the present embodiment, and the arrangement methods of the light guides in the light guide sheets according to the first to fifth embodiments are appropriately combined. Various configurations, modified examples, and modified examples realized by the above also belong to the technical scope of the present embodiment.
[0128]
(Seventh embodiment)
A seventh embodiment of the present invention will be described with reference to FIG.
[0129]
That is, this embodiment shows a configuration in which the light guide sheets according to the first to sixth embodiments are applied to a display lighting device (including a backlight).
[0130]
That is, when the light guide sheet according to the first to sixth embodiments is applied to a display lighting device (including a backlight), as shown in FIG. , Are arranged so as to correspond to the respective pixels 20 constituting the display 18.
[0131]
Thus, the light emitted from each light exit 6 is used as illumination light in accordance with the pixel 20 of the display 18.
[0132]
Further, as shown in FIG. 20, a light guide sheet formed by laminating two light guide sheets is used, and similarly, each light exit port 6 illuminates each pixel 20 constituting the display 18. For example, the light exit port 6 of the first light guide sheet is set to the blue pixel 20 of the display 18, and the light exit port 6 of the second light guide sheet is set to the red pixel 20 of the display 18. By doing so, a color display that does not require a color filter can be realized.
[0133]
Of course, a light guide sheet formed by laminating three light guide sheets is used. For example, the light exit port 6 of the first light guide sheet is connected to the blue pixel 20 of the display 18 by the second light guide sheet. A full color display that does not require a color filter is also realized by associating the light exit 6 with the red pixel 20 of the display 18 and the light exit 6 of the third light guide sheet with the green pixel 20 of the display 18, respectively. I can do it.
[0134]
Next, the operation of the light guide sheet according to the present embodiment configured as described above will be described.
[0135]
That is, when the light guide sheet according to the first to sixth embodiments is applied to a display lighting device (including a backlight), as shown in FIG. , Are arranged to correspond to the respective pixels 20 constituting the display 18.
[0136]
Thus, each pixel 20 of the display 18 is efficiently illuminated by the light emitted from each light exit port 6. That is, from the light guide sheet according to the first to sixth embodiments, since the emitted light of uniform intensity is obtained over the entire surface of the substrate 2, the display 18 is also uniformly formed over the entire display screen. Be illuminated.
[0137]
Further, by bonding a plurality of light guide sheets together, the light guide sheet can be applied as a lighting device for a color display, whereby a color display that does not require a color filter can be realized.
[0138]
Since the color filter transmits only a single wavelength of light, it absorbs nearly 70% of the incident light. Therefore, in a color display using a color filter, utilization efficiency of light supplied from the lighting device is low. Color filters are expensive because they are not easily manufactured.
[0139]
Therefore, by eliminating the need for such a color filter, it is possible to improve the light use efficiency and to realize a lighting device for a color display that is advantageous in cost.
[0140]
Although the preferred embodiments of the present invention have been described with reference to the accompanying drawings, the present invention is not limited to such configurations. Within the scope of the technical idea described in the claims, those skilled in the art can come up with various modified examples and modified examples, and these modified examples and modified examples are also within the technical scope of the present invention. It is understood that it belongs to.
[0141]
【The invention's effect】
As described above, according to the present invention, even when the size of the display screen increases, the light guide can emit light almost uniformly over the entire substrate without increasing the number of light guides. Sheet can be realized.
[0142]
Further, by using such a light guide sheet, even if the size of the display screen is increased, the thickness and weight of the display screen do not increase so much, and the display illumination can uniformly illuminate the entire display screen. The device can be realized.
[Brief description of the drawings]
FIG. 1 is a plan view showing a configuration example of a light guide sheet according to a first embodiment.
FIG. 2 is a perspective view showing an example of an arrangement state of a light guide on a substrate surface.
FIG. 3 is a perspective view showing an example of a cross-sectional shape of a light guide.
FIG. 4 is a conceptual diagram for explaining a scattering state of light inside a light guide.
FIG. 5 is a plan view showing another configuration example of the light guide sheet according to the first embodiment.
FIG. 6 is a sectional view showing a thickness distribution of a light guide on a substrate surface.
FIG. 7 is a plan view showing a light guide sheet in which light exit ports are provided at equal pitches in a light guide.
FIG. 8 is a plan view showing an example of a light guide sheet in which a light guide is arranged in a substantially spiral shape by a plurality of continuous linear portions.
FIG. 9 is a plan view showing another example of the light guide sheet in which the light guide is arranged in a substantially spiral shape by a plurality of continuous linear portions.
FIG. 10 is a plan view showing an example of a light guide sheet in which a curved light guide is partially arranged.
FIG. 11 is a plan view showing another example of the light guide sheet on which a curved light guide is partially disposed.
FIG. 12 is a plan view showing a configuration example of a light guide sheet according to a second embodiment.
FIG. 13 is a plan view showing another configuration example of the light guide sheet according to the second embodiment.
FIG. 14 is a plan view showing another configuration example of the light guide sheet according to the second embodiment.
FIG. 15 is a plan view showing another configuration example of the light guide sheet according to the second embodiment.
FIG. 16 is a plan view showing a configuration example of a light guide sheet according to a third embodiment.
FIG. 17 is a plan view showing a configuration example of a light guide sheet according to a fourth embodiment.
FIG. 18 is a plan view showing a configuration example of a light guide sheet according to a fifth embodiment.
FIG. 19 is a plan view showing a configuration example of a light guide sheet according to a sixth embodiment.
FIG. 20 is a plan view showing another configuration example of the light guide sheet according to the sixth embodiment.
FIG. 21 is a conceptual diagram showing an example of a method of applying the light guide sheet according to the first to sixth embodiments to a display lighting device.
[Explanation of symbols]
1, 10, 11, 12: light guide sheet, 2: substrate, 3, 13, 14, 15, 16: light guide, 4: light source, 5: incident light inlet, 6: light exit, 7, etc. Ends, 13a, 14a, 15a, 16a: Main part, 13b, 14b, 15b, 16b, 16c: Comb part, 18: Display, 20: Pixel

Claims (14)

Board and
A tubular light guide that is arranged by patterning on the surface of the substrate and guides the introduced light along a length direction when light is introduced from an end portion,
Each of the light guides is arranged at a different location on the surface of the light guide, and the light guided by the light guide is changed from the inside of the light guide to the outside so that the light intensity on the entire surface of the substrate becomes substantially constant. A light guide sheet having a plurality of light exit ports for emitting light. The light guide sheet according to claim 1,
A light guide sheet in which the light guide is arranged on the surface of the substrate so as to be formed of a plurality of continuous linear portions. The light guide sheet according to claim 1,
A light guide sheet in which the light guide is arranged to include at least a curved portion on the surface of the substrate. The light guide sheet according to claim 1,
A light guide sheet in which the light exit ports are arranged such that the arrangement density or the light exit area ratio on the surface of the light guide increases from the end where the light is introduced to the other end. The light guide sheet according to claim 1,
The cross-sectional area of the light guide in a cross section substantially orthogonal to the length direction is reduced from the end where the light is introduced toward the other end, and the light exit ports are connected to the light guide. A light guide sheet that is arranged at a substantially equal pitch on the surface of the body. The light guide sheet according to claim 1,
The cross-sectional area of the light guide body in a cross section substantially orthogonal to the length direction is increased from the end where the light is introduced toward the other end, and the distance between the light emitting ports adjacent to each other is increased. The light guide sheet in which the light exit ports are arranged so as to increase from the end where the light is introduced toward the other end. The light guide sheet according to claim 1,
The light guide,
A first arrangement pattern arranged on the surface of the substrate so as to include a plurality of continuous linear portions;
A second arrangement pattern arranged to include at least a curved portion on the surface of the substrate;
A third arrangement pattern arranged such that the arrangement density on the surface of the substrate increases from the end where the light is introduced toward the other end;
A fourth arrangement pattern in which a cross-sectional area of the light guide in a cross section substantially orthogonal to the length direction is arranged such that the cross-sectional area decreases from an end where the light is introduced toward the other end.
An arrangement pattern obtained by combining any two or more arrangement patterns of a fifth arrangement pattern arranged so that the cross-sectional area increases from the end where the light is introduced toward the other end. The light guide sheet is arranged according to. The light guide sheet according to claim 1,
The light guide sheet, wherein each of the light exit ports has substantially the same optical characteristics. The light guide sheet according to claim 1,
The light guide sheet, wherein each of the light exit ports has substantially the same arrangement density or area ratio of the light exit ports arranged in the light guide, and has substantially the same shape and size. The light guide sheet according to claim 1,
The light intensity is adjusted by adjusting the shape and size of each light emission port and the arrangement density or the area ratio of light emission ports arranged in the light guide, and the shape and size of the light guide and the arrangement pattern on the substrate. A light guide sheet that is made almost constant. The light guide sheet according to any one of claims 1 to 10, further comprising: a light source configured to supply light introduced into the light guide from an end of the light guide,
A display illumination device configured to illuminate the display by emitting light emitted from the light exit port toward a display to be illuminated. The light guide sheet according to any one of claims 1 to 10, further comprising: a light source configured to supply light introduced into the light guide from an end of the light guide,
A display lighting device configured to illuminate the display from the back by emitting light emitted from the light exit from the back of the display to be illuminated. The display lighting device according to claim 11 or 12,
A display illuminating device, wherein each of the light exits is arranged such that light emitted from each of the light exits illuminates each pixel constituting the display. The light guide sheet according to claim 7, comprising a light source that supplies light introduced into the light guide from an end of the light guide, and light emitted from the light exit port. A display illumination device that illuminates the display by emitting light toward a display that is an illumination target,
The display includes a plurality of pixels including three types of color sets RGB, and a display illumination in which the light exits are arranged such that light emitted from the light exits respectively illuminates the pixels. apparatus.

Images