JP2005085572A - Surface light source, electro-optical device, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface light source unit which can improve a utilization efficiency of light by reusing the light leaking from the opposite side end surface facing the incident side end surface of a light guide plate without generating luminance unevenness, an electro-optical device, and an electronic apparatus. <P>SOLUTION: In a surface light source unit 3 used as the back light device of the electro-optical device, LEDs 333 are directed toward the incident side end surface 311 of a light guide plate 31. Furthermore, a large number of optical fibers 4 are routed to guide the light leaking from the opposite side end surface 311 from the incident side end surface 311 to the light guide plate 31. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a surface light source unit that emits light toward an electro-optical panel such as a liquid crystal panel, an electro-optical device using the surface light source unit as a backlight device, and an electronic apparatus using the electro-optical device. is there.

  In an electro-optical device using a transmissive or transflective electro-optical panel in which an electro-optical material such as liquid crystal is sandwiched between a pair of substrates, a surface light source unit as a backlight device is provided on the back side of the electro-optical panel. A predetermined image is displayed using the light emitted from the surface light source unit.

  The surface light source unit includes at least a light source and a light guide plate. In a so-called sidelight-type backlight, the light source is disposed near the end of the light guide plate. Therefore, after the light emitted from the light source is incident on the light guide plate from the end face, the light travels in the light guide plate while being repeatedly reflected in the light guide plate, and is emitted from the surface facing the electro-optic panel (light emission surface). The

  Here, on the surface side (light emitting surface side) or the back surface side of the light guide plate itself, the light incident on the light guide plate can be uniformly emitted from the surface facing the electro-optical panel. A scattering pattern made up of irregularities is formed by a method such as printing or molding with a distribution obtained by optical design.

  In such a surface light source unit, for example, a cold cathode tube is used as the light source. Further, when the electro-optical device is used as a display unit of a mobile phone or a mobile computer, such a portable electronic device is battery-driven, so the surface light source unit is required to have low power consumption. In recent years, LEDs (light emitting diodes) are sometimes used as light sources (see, for example, Patent Document 1).

In addition, a configuration in which an optical fiber is disposed between the light source and the incident side end of the light guide plate and light emitted from the light source is incident on the light guide plate through the optical fiber is proposed (for example, Patent Document 2). reference).
Japanese Patent Application Laid-Open No. 8-160892 Japanese Patent Laid-Open No. 7-120751

  In a sidelight type backlight type surface light source unit, it is not possible to prevent light from leaking from the opposite end surface facing the incident side end surface of a part of the light incident on the light guide plate. For this reason, in the light guide plate, on the opposite end surface facing the incident side end surface, for example, measures such as forming a white or silver coating film are taken, but the light reflected by such a reflection surface is Even when the light enters the light guide plate again, there is a problem that the light is not uniformly emitted from the surface facing the electro-optical panel. That is, the scattering pattern formed on the front surface side (light emitting surface side) or the back surface side of the light guide plate itself has an optical design that assumes that light travels from the side where the light source is located. Therefore, there is a problem in that it is not effective for light traveling on the opposite side and causes uneven luminance.

  In view of the above problems, an object of the present invention is to improve the light utilization efficiency by reusing light leaking from the opposite end face facing the incident end face of the light guide plate without causing uneven brightness. An object of the present invention is to provide a surface light source unit that can be used, an electro-optical device using the surface light source unit, and an electronic apparatus using the electro-optical device.

  In order to solve the above-described problems, the present invention includes at least a light guide plate and a light source that causes light to enter the light guide plate from an incident side end surface of the light guide plate, and is located on the surface side of the light guide plate. In the surface light source unit that emits light from the light emitting surface, the light guide plate for reuse that causes light leaking from the opposite end surface facing the incident side end surface to be incident again from the incident side end surface by the light guide plate It is characterized by having.

  In the present invention, the light guide plate is provided with unevenness or a coating film on the front side or the back side for uniformizing the in-plane light quantity distribution of light incident from the incident side end face and emitted from the light exit face. It is preferred that a scattering pattern is constructed.

  In the present invention, the light guide member for reuse causes light to re-enter the position and direction that can eliminate luminance unevenness that occurs when the reuse light guide member is not used on the incident side end face. Is preferred.

  In the present invention, the reuse light guide member is preferably a plurality of optical fibers. If it is an optical fiber, it can be easily routed from the opposite end face of the light guide plate to the incident end face within a narrow space.

  In the present invention, the light source is preferably a point light source such as an LED. If it is point light sources, such as LED, power consumption can be restrained low compared with a cold cathode tube.

  In the present invention, it is preferable that an incident side end holding hole into which the incident side end of the optical fiber is inserted is formed on the opposite end surface of the light guide plate.

  In the present invention, it is preferable that an outer peripheral surface of the incident side end portion of the optical fiber is fixed to the light guide plate with an adhesive having reflectivity in a state of being inserted into the incident side end holding hole. . If the optical fiber is fixed with an adhesive having reflectivity, the outer peripheral surface of the incident side end of the optical fiber is coated with the adhesive having reflectivity. Therefore, light leakage from the outer peripheral surface of the optical fiber can be prevented, and the light reuse efficiency can be increased.

  In the present invention, it is preferable that an exit side end holding hole into which the exit side end of the optical fiber is inserted is formed on the entrance side end face of the light guide plate.

  In this invention, it is preferable that the said output side edge part of the said optical fiber is being fixed to the said light-guide plate with the insulating adhesive agent in the state inserted in the said output side edge part holding hole. When such an insulating adhesive is used, it is preferable that the light source is also fixed to the light guide plate by the adhesive to prevent the light source from dropping or misaligned.

  In this invention, it is preferable that the edge part of the said optical fiber is inserted in the said light-guide plate, and the said edge part is outside an effective light emission area. If comprised in this way, it can prevent that optical fiber itself comes out on a display surface. In the present invention, it is preferable that the insertion of the output side end portion of the optical fiber into the light guide plate is a position where the light can be irradiated where the amount of emitted light is significantly reduced.

  The surface light source unit to which the present invention is applied is used, for example, as a backlight device for an electro-optical panel by arranging the electro-optical panel on the light emission surface side of the light guide plate in the electro-optical device.

  An electro-optical device to which the present invention is applied is mounted as a display unit in an electronic device such as a mobile phone, a personal digital assistant, or a mobile computer.

  In the present invention, the light leaking from the opposite end surface of the light guide plate is incident again on the light guide plate by the reuse light guide member, so that the light use efficiency is high. In addition, the reuse light guide member makes light leaking from the opposite end face of the light guide plate enter again from the incident end face of the light guide plate. For example, the light guide member is incident on the front side or the back side of the light guide plate. Even when a scattering pattern composed of unevenness or a coating film is formed to make the in-plane light quantity distribution of light incident from the side end face and emitted from the light exit surface uniform, it is emitted uniformly from the light exit surface. The Therefore, the light leaking from the opposite end surface facing the incident side end surface of the light guide plate can be reused without causing uneven brightness, and the light utilization efficiency can be improved. In other words, since the driving voltage of the light source can be lowered accordingly, the power consumption can be reduced. Furthermore, the light guide member for reuse can be re-incident on the incident side side end surface at a position and orientation where luminance unevenness that occurs when the reuse light guide member is not used can be eliminated. Luminance unevenness that tends to occur when a light source is used can be eliminated.

  The best mode for carrying out the invention will be described with reference to the drawings.

(Overall configuration of electro-optical device)
FIG. 1 is an exploded perspective view showing the overall configuration of an electro-optical device with a backlight to which the present invention is applied. 2 is a cross-sectional view showing a configuration of a main part of the electro-optical device with a backlight shown in FIG.

  1 and 2, the electro-optical device 1 according to this embodiment is mounted as a display unit on a battery-driven electronic device such as a mobile phone, a PDA, a personal digital assistant, a mobile computer, or the like.

  The electro-optical device 1 includes a surface light source unit 3 (backlight device) including a metal lower shield plate 2 that also serves as a lower case, a frame-shaped spacer 8, a lower polarizing plate 61, an electro-optical panel 5, and an upper polarizing plate. 62, a metal upper shield plate 7 also serving as an upper case is stacked in this order, and each component has a generally rectangular planar shape. In housing these components between the lower shield plate 2 and the upper shield plate 7, a rectangular frame-shaped resin holder 9 is used in this embodiment, and the surface light source unit 3 and the spacer are placed inside the resin holder 9. 8, the lower polarizing plate 61 and the electro-optical panel 5 are arranged. Here, the spacer 8 secures a predetermined gap between the surface light source unit 3 and the electro-optical panel 5.

  A display window 71 having a size corresponding to an image display area of the electro-optical panel 5 described below is formed on the upper shield plate 7, and the upper shield plate 7 has an outer periphery of the image display area of the electro-optical panel 5. The electro-optical panel 5 is physically protected while covering the area.

In this embodiment, a TFT active matrix type transmissive liquid crystal panel is used as the electro-optical panel 5. As this type of liquid crystal panel, a well-known one can be used, and detailed description thereof is omitted. However, a TFT array substrate 51 in which pixels having pixel electrodes and pixel switching elements are formed in a matrix, Similarly, a counter substrate 52 having a counter electrode, a color filter, or the like formed on the surface of a substrate such as quartz glass or heat-resistant glass, a sealing material for bonding these substrates, and a region partitioned by the sealing material between the substrates The counter substrate 52, which is roughly composed of encapsulated and held liquid crystal as an electro-optical material, is smaller than the TFT array substrate 51, and the peripheral portion of the TFT array substrate 51 protrudes from the outer peripheral edge of the counter substrate 52. Is in a state. Therefore, on the TFT array substrate 51, a scanning circuit driving circuit, a data line driving circuit, and the like using a driving circuit TFT (not shown) formed simultaneously with the pixel switching TFT around the image display area. Can be formed. Further, if input / output terminals are formed in the TFT array substrate 51 in a region protruding from the end of the counter substrate 52, a driving IC 54 is COF-mounted on these input / output terminals as shown in FIG. A flexible substrate 53 can be mounted. In this embodiment, the flexible substrate 53 is further connected with a flexible substrate 56 on which various electronic components 55 constituting a power circuit of the surface light source unit 3 and the like are mounted. 56 elongated portions 57 are connected to the LED mounting substrate 330 of the surface light source unit 3.

  In the electro-optical device 1 configured as described above, normally white mode / normally black is provided on the TFT array substrate 51 side (light incident side) and the counter substrate 52 side (light emission side) of the electro-optical panel 5. Depending on the mode, a lower polarizing plate 61 and an upper polarizing plate 62 made of a plastic sheet are arranged in a predetermined direction.

  In this embodiment, the light from the surface light source unit 3 for the backlight device is incident from the TFT array substrate 51 and is emitted from the counter substrate 52. A configuration in which light is incident from the substrate 52 and is emitted from the TFT array substrate 51 may be employed. Further, as the electro-optical panel 5, in addition to the TFT active matrix type transmissive liquid crystal panel, a TFD active matrix type transmissive liquid crystal panel, a passive matrix type transmissive liquid crystal panel, or the like may be used. Further, not only the transmissive liquid crystal panel but also a semi-transmissive / reflective liquid crystal panel may be used.

(Detailed configuration of the surface light source unit 3)
FIG. 3 is a plan view showing the positional relationship between the light guide plate and the optical fiber of the surface light source unit shown in FIG. 4 and 5 are an explanatory view of the vicinity of the opposite end face of the light guide plate used in the surface light source unit shown in FIG. 1 and an explanatory view of the vicinity of the incident end face of the light guide plate.

  1 and 2, a surface light source unit 3 used as a backlight device in the electro-optical device 1 of this embodiment includes a rectangular light guide plate 31 made of a resin molded product having translucency, a glass-epoxy substrate, and the like. And a light source unit 33 including an LED mounting substrate 330 made of a flexible substrate having a multilayer wiring structure or a flexible substrate having a multilayer wiring structure. In the surface light source unit 3, the reflection sheet 35 and the lower shield plate 2 are disposed in this order on the lower surface side of the light guide plate 31, while the lens sheet, the diffusion sheet, and the like are disposed on the upper surface side of the light guide plate 31. A sheet-like optical component 37 is arranged.

  In the light source unit 33, a thinly cut substrate is used as the LED mounting substrate 330, and a plurality of chip-shaped LEDs 333 as light emitting elements are mounted in a row on the upper surface of the LED mounting substrate 330.

  Here, all the LEDs 333 have the outgoing optical axis directed in a direction parallel to the mounting surface of the LED mounting substrate 330. For this reason, the LED mounting substrate 330 is disposed with the surface on which the LED 333 is mounted facing downward, the LED 333 is opposed to the incident side end surface 311 of the light guide plate 31, and arranged along the incident side end surface 311. .

  In the surface light source unit 3 of this embodiment, a scattering pattern (not shown) is formed on the front surface (light emitting surface 315) or the back surface side of the light guide plate 31. This scattering pattern is composed of unevenness or a coating film for uniformizing the in-plane light quantity distribution of light incident from the incident end face 311 and emitted from the light exit face 315, and is on the incident side end face 311 side of the light guide plate 31. Is formed in a coarse distribution, and is formed in a dense distribution on the side of the opposite end face 312 facing the incident end face 311.

  In the surface light source unit 3 of this embodiment, as shown in FIGS. 1 and 3, light leaking from the opposite end surface 311 facing the incident side end surface 311 through the light guide plate 31 is incident again from the incident side end surface 311. A large number of optical fibers 4 are routed on the side of the light guide plate 31 as reuse light guide members. That is, the multiple optical fibers 4 are routed so that the incident-side end 41 is disposed on the opposite-side end surface 311 of the light guide plate 31, while the emission-side end 42 is positioned on the incident-side end surface 311. ing.

  In arranging the optical fiber 4 in this way, in this embodiment, as shown in FIG. 4, the incident-side end holding portion in which the incident-side end 41 of the optical fiber 4 is inserted into the opposite end surface 312 of the light guide plate 31. In the state where the hole 313 is formed and the incident side end 41 of the optical fiber 4 is inserted into the incident side end holding hole 313, a silver paste 46 as a reflective adhesive is provided on the opposite end surface 312. It has been applied. The region where the silver paste 46 is applied is the entire surface of the opposite end surface 312 and the outer peripheral surface of the incident side end portion 41 of the optical fiber 4 as shown by the slanting line to the right in FIG. The light guide plate 31 is fixed with a silver paste 46. In addition, the outer peripheral surface of the incident side end 41 of the optical fiber 4 is in a state of being coated with a silver paste 46.

  Here, the incident side end holding hole 313 extends in parallel with the central optical axis of the LED 333. The insertion length of the incident side end 41 of the optical fiber 4 into the light guide plate 31 is, for example, several mm to several tens mm, and the incident side end 41 of the optical fiber 4 emits light from the light guide plate 31. Of the surface 315, the amount of emitted light is substantially uniform and is located outside the effective light emitting area 310 that is actually used for display on the electro-optical device 1.

  On the other hand, as shown in FIG. 5, on the incident side end surface 311 of the light guide plate 31, the emission side end portion into which the emission side end portion 42 of the optical fiber 4 is inserted between the positions where the LEDs 333 are arranged. In the state where the holding hole 314 is formed and the emission side end 42 of the optical fiber 4 is inserted into the emission side end holding hole 314, the incident side end face 311 is molded with an insulating adhesive 47. The region molded with the insulating adhesive 47 includes the LED 333 as well as the output side end portion 42 of the optical fiber 4 as shown by a one-dot chain line in FIG. Is within the range that can be completely molded.

  In this manner, if the LED 333 is molded with the insulating adhesive 47, there is no possibility of short circuit, and even when an impact is applied, the position and displacement of the LED 333 can be prevented.

  Here, the emission side end holding hole 314 extends parallel to the central optical axis of the LED 333. The insertion length of the emission side end portion 42 of the optical fiber 4 into the light guide plate 31 is several mm to several tens mm, and the emission side end portion 42 of the optical fiber 4 is located outside the effective light emitting area 310.

(Operation of this form, main effect)
In the electro-optical device 1 configured as described above, when the LED 333 is turned on by the surface light source unit 3, the light emitted from the LED 333 enters the light guide plate 31, and as indicated by an arrow L 1, Alternatively, the light travels in the light guide plate 31 while being repeatedly reflected by the reflection sheet 35, and is emitted toward the light emission surface 315 (the sheet-like optical component 37 side) that is the upper surface of the light guide plate 31. The light incident on the sheet-like optical component 37 is subjected to an action such as a scattering pattern formed on the light guide plate 31 itself or a light scattering property imparted by the sheet-like optical component 37, and then applied to the electro-optical panel 5. Emitted. On the other hand, in the electro-optical panel 5, the alignment state of the liquid crystal is controlled for each pixel by an image signal applied to the pixel electrode. For example, when the electro-optical panel 5 is configured in the TN mode, the liquid crystal is twisted and oriented at an angle of 90 ° between the substrates, and such twisted orientation is released by applying an electric field to the liquid crystal between the substrates. . Accordingly, the alignment state of the liquid crystal can be controlled for each pixel depending on whether or not an electric field is applied between the substrates.

  Therefore, in the electro-optical panel 5, the light emitted from the surface light source unit 3 is aligned with predetermined linearly polarized light by the lower polarizing plate 61 on the incident side, and then enters the liquid crystal layer and passes through a certain region. The linearly polarized light that is transmitted is emitted with the transmission polarization axis twisted, while the linearly polarized light that has passed through the other region is emitted without the transmission polarization axis being twisted. For this reason, if the lower polarizing plate 61 on the incident side and the upper polarizing plate 62 on the outgoing side are arranged so that their transmission polarization axes are orthogonal to each other (normally white), they are arranged on the outgoing side of the electro-optical panel 5. Further, only the linearly polarized light whose transmission polarization axis is twisted by the liquid crystal passes through the upper polarizing plate 62. On the other hand, if the upper polarizing plate 62 on the output side is arranged so that the transmission side polarization axis is parallel to the lower polarizing plate 61 on the incident side (normally black), it is arranged on the output side of the electro-optical panel 5. Only the linearly polarized light that does not twist the transmission polarization axis by the liquid crystal passes through the upper polarizing plate 62. Therefore, arbitrary information can be displayed by controlling the alignment state of the liquid crystal for each pixel.

  In this embodiment, the light leaking from the opposite end surface 312 of the light guide plate 31 is guided to the incident side end surface 312 of the light guide plate 31 by the optical fiber 4 and again from the incident side end surface 311 as indicated by an arrow L2. Since it is incident on the light guide plate 31, the light use efficiency is high.

  Moreover, the optical fiber 4 causes the light leaking from the opposite end surface 312 of the light guide plate 31 to enter again from the incident side end surface 312 of the light guide plate 31. Therefore, the light incident on the light guide plate 31 again by the optical fiber 4 is incident on the light guide plate 31 in the same manner as the light (indicated by the arrow L1) directly incident on the light guide plate 31 from the LED 333, as indicated by the arrow L3. From the side end face 312 to the opposite end face 312. For this reason, even when a scattering pattern for the light incident on the light guide plate 31 directly from the LED 333 is formed on the front surface side or the back surface side of the light guide plate 3, the light incident on the light guide plate 31 again by the optical fiber 4 is The light is emitted uniformly from the light exit surface 315. Therefore, the light leaking from the opposite end surface facing the incident side end surface 311 of the light guide plate 31 can be reused without causing luminance unevenness, and the light utilization efficiency can be improved. In other words, since the driving voltage of the LED 333 can be lowered accordingly, the power consumption can be reduced.

  In addition, since the outer peripheral surface of the incident side end 41 of the optical fiber 4 is coated with the silver paste 46, light leakage from the outer peripheral surface of the incident side end 41 of the optical fiber 4 can be prevented. it can.

  Furthermore, with respect to the optical fiber 4, light can be re-incident at a position and orientation that can eliminate luminance unevenness that occurs when the optical fiber 4 is not used, and thus when a point light source such as an LED 333 is used as a point light source Therefore, it is possible to completely eliminate the uneven brightness. That is, between the positions where the LEDs 333 are disposed is a portion where the amount of light from the LEDs 333 is small, and if the emission side end portion 42 of the optical fiber 4 is disposed between the positions where the LEDs 333 are disposed, the luminance unevenness is eliminated. it can. In addition, since the exit-side end holding hole 314 has an inner diameter larger than the outer diameter of the optical fiber 4, the exit of the optical fiber 4 in the direction in which the luminance unevenness can be eliminated inside the exit-side end holding hole 314. The side end 42 can also be directed.

  In addition, since the emission side end portion 42 of the optical fiber 4 is located outside the effective light emitting area 310, light is emitted from the optical fiber 4 in a spot manner to a region where the amount of emitted light is significantly reduced. Even in such a case, the dark portion is not formed by the optical fiber 4.

  As described above, according to the present embodiment, luminance unevenness or the like when using a point light source such as the LED 333 can be eliminated. Therefore, even when the LED 333 that requires a low driving voltage is used as the light source, the image displayed on the electro-optical device 1 High quality. Therefore, the electro-optical device 1 according to this embodiment can display high-quality images even in battery-powered electronic devices such as a mobile phone, a personal digital assistant, and a mobile computer.

(Other embodiments)
In the above embodiment, both the incident side end 41 and the emission side end 42 of the optical fiber 4 are inserted into the light guide plate 31, but the opposite end surface 312 and the incident side end surface 311 of the light guide plate 31. You may employ | adopt the structure which opposes.

  Moreover, in the said form, although the optical fiber 4 was routed by the side of the light-guide plate 31, the structure routed by the back surface side may be employ | adopted.

  Moreover, in the said form, although the optical fiber 4 was arrange | positioned in 1 row, you may employ | adopt the structure arranged in 2 or more rows.

  In the present invention, the light leaking from the opposite end surface of the light guide plate is incident again on the light guide plate by the reuse light guide member, so that the light use efficiency is high. In addition, the reuse light guide member makes light leaking from the opposite end face of the light guide plate enter again from the incident end face of the light guide plate. For example, the light guide member is incident on the front side or the back side of the light guide plate. Even when a scattering pattern composed of unevenness or a coating film is formed to make the in-plane light quantity distribution of light incident from the side end face and emitted from the light exit surface uniform, it is emitted uniformly from the light exit surface. The Therefore, the light leaking from the opposite end surface facing the incident side end surface of the light guide plate can be reused without causing uneven brightness, and the light utilization efficiency can be improved. In other words, since the driving voltage of the light source can be lowered accordingly, the power consumption can be reduced. Furthermore, the light guide member for reuse can be re-incident on the incident side side end surface at a position and orientation where luminance unevenness that occurs when the reuse light guide member is not used can be eliminated. Luminance unevenness that tends to occur when a light source is used can be eliminated.

1 is an exploded perspective view showing an overall configuration of a backlit electro-optical device to which the present invention is applied. FIG. 2 is a cross-sectional view illustrating a configuration of a main part of the electro-optical device with a backlight illustrated in FIG. 1. It is a top view which shows the positional relationship of the light-guide plate and optical fiber of the surface light source unit shown in FIG. It is explanatory drawing of the other side end surface vicinity of the light-guide plate used for the surface light source unit shown in FIG. It is explanatory drawing of the incident side end surface vicinity of the light-guide plate used for the surface light source unit shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electro-optic device, 3 surface light source unit (backlight apparatus), 4 optical fiber (reuse light guide member), 5 electro-optic panel, 31 light guide plate, 33 light source part, 41 incident side edge part of optical fiber, 42 End portion of optical fiber, 46 silver paste (adhesive with reflectivity), 47 insulating adhesive, 51 TFT array substrate, 52 counter substrate, 310 effective light emitting area, 311 incident side end surface of light guide plate, 312 Opposite side end face of light guide plate, 313 Incident side end holding hole, 314 Outgoing side end holding hole, 315 Light emitting face of light guide plate, 330 LED mounting substrate, 333 Chip type LED (point light source)

Claims (13)

In a surface light source unit that has at least a light guide plate and a light source that causes light to enter the light guide plate from an incident side end surface of the light guide plate, and emits light from a light output surface located on the surface side of the light guide plate ,
The surface light source unit further includes a reuse light guide member that causes light leaking from the opposite end surface facing the incident side end surface to enter again from the incident side end surface.   2. The surface or back side of the light guide plate according to claim 1, comprising unevenness or a coating film for uniformizing in-plane light quantity distribution of light incident from the incident side end face and emitted from the light exit surface. A surface light source unit comprising a scattering pattern.   3. The reuse light guide member according to claim 1, wherein the reuse light guide member recycles light to a position and direction that can eliminate luminance unevenness that occurs when the reuse light guide member is not used on the incident side end face. A surface light source unit characterized by being incident.   4. The surface light source unit according to claim 1, wherein the reuse light guide member is a plurality of optical fibers.   5. The surface light source unit according to claim 4, wherein the light source is a point light source.   6. The surface light source unit according to claim 4, wherein an incident side end holding hole into which an incident side end of the optical fiber is inserted is formed on the opposite end surface of the light guide plate.   In Claim 6, the said incident side edge part of the said optical fiber has the outer peripheral surface fixed to the said light-guide plate with the adhesive agent provided with reflectivity in the state inserted in the said incident side edge part holding hole. A characteristic surface light source unit.   8. The surface according to claim 4, wherein an exit-side end holding hole into which an exit-side end of the optical fiber is inserted is formed in the entrance-side end surface of the light guide plate. 9. Light source unit.   9. The surface light source according to claim 8, wherein the output side end portion of the optical fiber is fixed to the light guide plate with an insulating adhesive while being inserted into the output side end holding hole. unit.   The surface light source unit according to claim 9, wherein the light source is also fixed to the light guide plate by the insulating adhesive.   11. The surface light source unit according to claim 4, wherein an end portion of the optical fiber is inserted into the light guide plate, and the end portion is outside an effective light emitting area. For the surface light source unit defined in any one of claims 1 to 11, an electro-optic panel is disposed on the light emitting surface side of the light guide plate,
The electro-optical device, wherein the surface light source unit is used as a backlight device for the electro-optical panel.   An electronic apparatus using the electro-optical device defined in claim 12.

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