JP2005353430A - Plane light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce cost of component and assembling cost of a plane light source device as a whole by structuring the plane light source with the small number of the components capable of obtaining any given chromaticity. <P>SOLUTION: A light guide plate 1 is structured by integrally forming a chromatic correction filter layer 20 on a light-irradiating face 101 of a translucent light guide layer 10. Furthermore, a plurality of diffusion dots 5a are printed on a reflective face 102 of the light guide plate 1. Then, a reflective plate 2, the light guide plate 1, a diffusion plate 4, and prism sheets 3b, 3a are arranged in lamination in that order, and a light source 11 and a lamp reflector 12 are arranged at given places in relation to the light guide plate 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a surface light source device used for a backlight such as a liquid crystal display device, and more particularly to a surface light source device capable of obtaining an arbitrary chromaticity.

  A conventional surface light source device will be described with reference to the drawings.

  FIG. 7 is an exploded perspective view showing a configuration of a main part of a conventional surface light source device. FIG. 8 is an exploded partial sectional view of the surface light source device shown in FIG.

  As shown in FIGS. 7 and 8, the surface light source device is disposed in contact with the light transmissive light guide plate 1 that guides the light incident from the side surface 103 to the light output surface 101, and the light output surface 101 of the light guide plate 1. A diffuser plate 4, two prism sheets 3 a and 3 b disposed on the upper surface of the diffuser plate 4, and a plurality of diffusion dots 5 provided on the reflective surface 102 facing the light exit surface 101 of the light guide plate 1, The reflecting plate 2 disposed in contact with the reflecting surface 102, the tubular light source 11 disposed along the side surface 103 of the light guide plate 1, and the light emitted from the light source 11 is reflected to enter the light guide plate 1 from the side surface 103. The lamp reflector 12 to be operated.

  Light generated by the light source 11 enters the light guide plate 1 from the side surface 103 directly or through reflection by the lamp reflector 12. The light incident on the light guide plate 1 reaches the light output surface 101 and is emitted to the outside in a planar shape. Here, the reflecting surface 102 of the light guide plate 1 is provided with a plurality of diffusion dots 5 with a predetermined shape and pitch, and the light incident on the light guide plate 1 is uniformly diffused over the entire light exit surface 101. The light diffused in this way is reflected by the reflecting plate 2 installed on the reflecting surface 102 and guided to the light exiting surface 101. Next, the planar light emitted from the light exit surface 101 is further diffused through the diffusion plate 4 and condensed in the normal direction of the light exit surface 101 by the prism sheets 3a and 3b.

  In such a surface light source device, the reflection plate 2, the light guide plate 1, the diffusion plate 4, and the prism sheets 3 a and 3 b are sequentially stacked, and the light source 11 is installed along the side surface 103 of the light guide plate 1. The lamp reflector 12 is installed at a predetermined position, and these are housed in a frame (not shown).

  By the way, in the liquid crystal display device using the surface light source device described above, it is necessary to correct the chromaticity according to the intended use.

Therefore, as a conventional surface light source device, a chromaticity correction filter sheet for correcting the chromaticity of light from the light source is installed between the light guide plate and the reflection plate (see, for example, Patent Document 1 and Patent Document 2). ).
JP-A-4-361231 JP 2000-206524 A

  However, such a conventional surface light source device is configured by combining a plurality of parts as described above, and an operator assembles these parts manually, so that the number of work steps increases. Furthermore, when a chromaticity correction filter sheet is used, the number of work steps increases accordingly.

  In addition, with the increase in the number of work steps, minute dust or the like may adhere between each plate or sheet. When dust adheres in this way, unevenness occurs in the planar light emitted from the apparatus, or the adhered dust is projected, so that it cannot be used as a surface light source. For this reason, it may be necessary to reassemble again.

  In addition, since the number of parts is large, the parts cost of the surface light source device is increased accordingly.

  An object of the present invention is to configure a surface light source device capable of obtaining an arbitrary chromaticity with a small number of parts.

  The present invention corrects the chromaticity of light on the light exit surface of the light guide plate in a surface light source device including a light guide plate that guides light incident from at least one end face to the light exit surface and emits light in a planar shape from the light exit surface. A chromaticity correction filter layer is integrally formed.

  In this configuration, since the chromaticity correction filter layer integrally formed on the light output surface of the light guide plate has a function of correcting the chromaticity of the emitted light, it is not necessary to provide a separate chromaticity correction filter sheet. That is, the chromaticity correction filter sheet can be omitted.

  The present invention also includes a light guide plate that guides light incident from at least one end face to the light exit surface, and emits light in a planar shape from the light exit surface, and is disposed on the light exit surface side of the light guide plate. In a surface light source device including a diffuser plate to be diffused, a chromaticity correction filter layer for correcting the chromaticity of light is integrally formed on the light exit surface side of the light guide plate in the diffuser plate.

  In this configuration, since the chromaticity correction filter layer of the diffusion plate has a function of correcting the chromaticity of light from the light guide plate, it is not necessary to provide a separate chromaticity correction filter sheet. That is, the chromaticity correction filter sheet can be omitted.

  The present invention also includes a light guide plate that guides light incident from at least one end face to the light exit surface, and emits light in a planar shape from the light exit surface, and is disposed on the light exit surface side of the light guide plate. In a surface light source device including a prism plate that condenses light in the normal direction of the light exit surface and a diffusion plate that diffuses light from the light exit surface of the light guide plate, the chromaticity of light on the light exit surface side of the light guide plate in the prism plate It is characterized in that a chromaticity correction filter layer for correcting the above is integrally formed.

  In this configuration, since the chromaticity correction filter layer of the prism plate has a function of correcting the chromaticity of light from the light guide plate, it is not necessary to provide a separate chromaticity correction filter sheet. That is, the chromaticity correction filter sheet can be omitted.

  According to the present invention, the number of components can be reduced even in a surface light source device capable of obtaining an arbitrary chromaticity by integrally forming the chromaticity correction filter layer on the light exit surface side of the light guide plate. , Component costs can be reduced. In addition, since the work of sequentially stacking and arranging the chromaticity correction filter sheet and the light guide plate as in the past can be omitted, the work cost can be reduced. In addition, since it is not necessary to stack the chromaticity correction filter sheet and the light guide plate, there is no possibility that dust or the like will adhere between the chromaticity correction filter sheet and the light guide plate, and the product yield can be improved.

  Further, according to the present invention, even if the surface light source device can obtain an arbitrary chromaticity by integrally forming the chromaticity correction filter layer on the light exit surface side of the light guide plate in the diffusion plate, the number of components can be reduced. The number of parts can be reduced, and the part cost can be reduced. Further, since the work of sequentially stacking and arranging the chromaticity correction filter sheet and the diffusion plate as in the prior art can be omitted, the work cost can be reduced. In addition, since it is not necessary to stack the chromaticity correction filter sheet and the diffusion plate, there is no possibility that dust or the like will adhere between the chromaticity correction filter sheet and the diffusion plate, and the product yield can be improved.

  Further, according to the present invention, even if the surface light source device can obtain an arbitrary chromaticity by integrally forming the chromaticity correction filter layer on the light exit surface side of the light guide plate in the prism sheet, the number of components can be reduced. The number of parts can be reduced, and the part cost can be reduced. Further, since the work of sequentially stacking and arranging the chromaticity correction filter sheet and the prism sheet as in the prior art can be omitted, the work cost can be reduced. In addition, since it is not necessary to stack the chromaticity correction filter sheet and the prism sheet, there is no possibility that dust or the like adheres during the assembling operation, and the product yield can be improved.

  The surface light source device according to the first embodiment will be described with reference to the drawings.

  FIG. 1 is an exploded perspective view showing a configuration of a main part of the surface light source device according to the present embodiment. FIG. 2 is an exploded partial sectional view of the surface light source device shown in FIG. In FIG. 2, the diffusing dots 5 are represented by symbols, and the other symbols are omitted.

  As shown in FIGS. 1 and 2, the surface light source device includes a light guide plate 1 that guides light incident from the side surface 103 to the light output surface 101, and a diffusion plate 4 that is disposed on the light output surface 101 side of the light guide plate 1. The prism sheets 3 a and 3 b disposed on the upper surface of the diffusion plate 4, the reflection plate 2 disposed in contact with the reflection surface 102 facing the light exit surface 101 of the light guide plate 1, and the side surface 103 of the light guide plate 1. The tubular light source 11 and the lamp reflector 12 that reflects the light emitted from the light source 11 and enters the light guide plate 1 from the side surface 103 are housed in a frame (not shown).

  The light guide plate 1 includes a translucent light guide layer 10 and a chromaticity correction filter layer 20 that corrects the chromaticity of light emitted from the light guide layer 10. In addition, a plurality of diffusion dots 5 are printed in a predetermined shape on the reflection surface 102 of the light guide layer 10.

  The light guide plate 1 having such a configuration is formed by the following method.

  First, the light guide layer 10 is formed by molding a light-transmitting substrate made of acrylic (PMMA), polycarbonate (PC), or the like to a predetermined area and thickness, and one surface of the light guide layer 10 ( A plurality of diffusion dots 5 are printed on the reflection surface 102 using, for example, milky white ink. The diffusion dots 5 are printed in a predetermined pattern on the entire reflecting surface 102 of the light guide layer 10. This print pattern is set to a pattern in which light is uniformly applied to the light exit surface 101 of the light guide layer 10 by the light hitting each diffused dot 5 and diffusing. For example, small dots are formed near the side surface 103. Printed, large dots are printed as they move away.

  Next, a chromaticity correction filter layer 20 that corrects light from the light guide layer 10 to a predetermined chromaticity is formed on the light exit surface 101 of the light guide layer 10 with a predetermined thickness. At this time, the chromaticity correction filter layer 20 is formed by a method of forming a predetermined color ink on the light exit surface of the light guide layer 10 by using transfer, painting, printing, or the like, or by a predetermined chromaticity. A method of adhering the chromaticity correction filter sheet to the light exit surface of the light guide layer 10 is used.

  Thus, the diffusion plate 4 is disposed on the upper surface of the chromaticity correction filter layer 20 of the light guide plate 1 in which the light guide layer 10 and the chromaticity correction filter layer 20 are integrally formed. Next, prism sheets 3b and 3a for condensing light in the normal direction of the light exit surface 101 are sequentially arranged on the upper surface where the light guide plate 1 and the diffusion plate 4 are sequentially laminated. Here, on the prism sheets 3a and 3b, a large number of prisms each having a substantially triangular cross section are formed side by side in parallel. For example, as shown in the drawing, the prism sheet 3a has a prism ridge line that is the axis of the light source 11. The prism sheet 3 b is arranged in a direction in which the prism ridge line is perpendicular to the axial direction of the light source 11.

  A light source 11 such as a cold cathode tube lamp (CFL) is disposed at a predetermined position with respect to the light guide plate 1, and the light emitted from the light source 11 in the entire circumferential direction is effectively incident on the light guide plate 1. A lamp reflector 12 is disposed.

  By setting it as such a structure, since the chromaticity correction filter layer is integrally formed previously by the light-guide plate, the number of parts which comprise a surface light source device can be reduced. Thereby, while being able to reduce the part cost of a surface light source device, since the number of work processes reduces, work cost can be reduced. In addition, when a chromaticity correction filter sheet is separately provided, dust or the like may adhere between the light guide plate and the chromaticity correction filter sheet. There will be no garbage non-delivery and the yield will be improved.

  In this embodiment, the prism sheets 3b and 3a are arranged in this order. However, the prism sheets 3a and 3b may be arranged in this order.

  Alternatively, the prism sheets 3b and 3a may be arranged in this order with the prism facing downward.

  Furthermore, the light guide plate, the prism sheet, and the diffusion plate may be stacked in this order.

  In this embodiment, the chromaticity correction filter layer is formed only on the light exit surface 101 of the light guide layer 10. However, the chromaticity correction filter layer is also formed on the reflection surface 102 and the side surface 103 on which light from the light source 11 is incident. You may form.

  Next, a surface light source device according to a second embodiment will be described with reference to the drawings.

  FIG. 3 is an exploded perspective view showing the configuration of the main part of the surface light source device according to this embodiment. FIG. 4 is an exploded partial cross-sectional view of the surface light source device shown in FIG.

  In the surface light source device shown in FIGS. 3 and 4, the diffusion plate 4 is formed by integrally forming the diffusion layer 40 and the chromaticity correction filter layer 41, and the light guide plate 1 is formed of only the light guide layer. . Other configurations are the same as those of the surface light source device shown in FIGS.

  The diffusing plate 4 shown in the present embodiment is first made of a material containing a metal alloy piece, fine particles, resin beads such as acrylic, a reflective luminescent substance, a fluorescent pigment, etc. on one surface of a base sheet of a translucent substrate. The diffusion layer 40 is formed by using a method such as vapor deposition, sputtering, transfer, plating, painting, printing, adhesion, or the like. Then, the chromaticity correction filter layer is formed on the other surface of the base sheet as described above.

  The diffusion plate 4 is arranged with the chromaticity correction filter layer 41 facing the light guide plate 1 side.

  By using such a configuration, the chromaticity correction and diffusion of the planar light can be performed only by the diffusion plate 4.

  Thereby, the number of parts which comprise a surface light source device can be reduced similarly to 1st Embodiment. In addition, the component cost of the surface light source device can be reduced and the number of work steps can be reduced, so that the work cost can be reduced. Furthermore, when a separate chromaticity correction filter sheet is provided, dust or the like may adhere between the diffuser plate and the chromaticity correction filter sheet. There will be no garbage non-delivery and the yield will be improved.

  Further, since the chromaticity correction filter layer is integrally formed on the diffusion plate, the chromaticity correction of the planar light can be performed without providing the chromaticity correction filter layer on the light guide plate. Thereby, it is possible to perform chromaticity correction even using a conventionally used light guide plate.

  Next, a surface light source device according to a third embodiment will be described with reference to the drawings.

  FIG. 5 is an exploded perspective view showing the configuration of the main part of the surface light source device according to the present embodiment. FIG. 6 is an exploded partial sectional view of the surface light source device shown in FIG.

  In the surface light source device shown in FIGS. 5 and 6, the prism sheet 3b is formed by integrally forming the prism layer 31b and the chromaticity correction filter layer 32b, and the light guide plate 1 is formed only of the light guide layer. . The prism sheet 3b, 3a and the diffusion plate 4 are sequentially stacked on the light output surface 101 of the light guide plate 1. Here, the prism sheet 3b is arranged with the chromaticity correction filter layer 32b facing the light guide plate 1 side. Other configurations are the same as those of the surface light source device shown in FIGS.

  In the prism sheet 3b shown in the present embodiment, a prism layer 31b is formed by arranging a large number of prisms each having a substantially triangular cross section on one side of the base sheet while keeping them parallel to each other. A degree correction filter layer 32b is formed.

  With such a configuration, it is possible to perform chromaticity correction and light collection in the normal direction of the light exit surface by the prism sheet.

  Thereby, the number of parts which comprise a surface light source device can be reduced similarly to the 1st and 2nd embodiment. In addition, the component cost of the surface light source device can be reduced and the number of work steps can be reduced, so that the work cost can be reduced. In addition, when a chromaticity correction filter sheet is separately provided, dust or the like may adhere between the prism sheet and the chromaticity correction filter sheet. There will be no garbage non-delivery and the yield will be improved.

  Further, since the chromaticity correction filter layer is integrally formed on the prism sheet, the chromaticity correction of the planar light can be performed without providing the chromaticity correction filter layer on the light guide plate. Thereby, it is possible to perform chromaticity correction even using a conventionally used light guide plate.

The disassembled perspective view which shows the structure of the principal part of the surface light source device which concerns on 1st Embodiment. 1 is an exploded partial cross-sectional view of a surface light source device according to a first embodiment. The disassembled perspective view which shows the structure of the principal part of the surface light source device which concerns on 2nd Embodiment. Exploded partial sectional view of a surface light source device according to a second embodiment The disassembled perspective view which shows the structure of the principal part of the surface light source device which concerns on 3rd Embodiment. Exploded partial sectional view of a surface light source device according to a third embodiment The exploded perspective view which shows the structure of the principal part of the conventional surface light source device. Disassembled partial sectional view of a conventional surface light source device

Explanation of symbols

1-light guide plate 2-reflecting plates 3a, 3b-prism sheet 4-diffusion plate 5-diffusion dot 11-light source 12-lamp reflector 10-light guide layer 20 of light guide plate 1-chromaticity correction filter layer 31b of light guide plate 1 -Prism layer 32b of prism sheet 3b-chromaticity correction filter layer 40 of prism sheet 3b-diffusion layer 41 of diffusion plate 4-chromaticity correction filter layer of diffusion plate 4

Claims (4)

A light guide plate that guides light incident from at least one side surface to the light exit surface and emits light in a planar shape from the light exit surface, and is disposed on the light exit surface side of the light guide plate. In a surface light source device comprising a prism plate that condenses in a line direction and a diffusion plate that diffuses light from the light exit surface of the light guide plate,
(1) The light guide plate integrally forms a chromaticity correction filter layer for correcting chromaticity of light on the light exit surface.
(2) Or, the diffuser plate is integrally formed with a chromaticity correction filter layer for correcting the chromaticity of light on the light exit surface side of the light guide plate.
(3) Or, the prism plate is integrally formed with a chromaticity correction filter layer for correcting the chromaticity of light on the light exit surface side of the light guide plate. In a surface light source device including a light guide plate that guides light incident from at least one side surface to a light exit surface and emits light in a planar shape from the light exit surface.
The surface light source device, wherein the light guide plate is integrally formed with a chromaticity correction filter layer for correcting chromaticity of light on the light exit surface. A light guide plate that guides light incident from at least one side surface to the light exit surface and emits light in a planar shape from the light exit surface; and a diffusion plate that is disposed on the light exit surface side of the light guide plate and diffuses the light from the light exit surface In a surface light source device comprising:
2. The surface light source device according to claim 1, wherein the diffuser plate is integrally formed with a chromaticity correction filter layer for correcting the chromaticity of light on the light exit surface side of the light guide plate. A light guide plate that guides light incident from at least one side surface to the light exit surface and emits light in a planar shape from the light exit surface, and is disposed on the light exit surface side of the light guide plate. In a surface light source device comprising a prism plate that condenses in a line direction and a diffusion plate that diffuses light from the light exit surface of the light guide plate,
The surface light source device, wherein the prism plate is integrally formed with a chromaticity correction filter layer for correcting chromaticity of light on a light exit surface side of the light guide plate.

Images