JP5822740B2 - Surface light source device - Google Patents

Description

  The present invention relates to a surface light source device including a light guide unit that emits light incident from a plate-shaped end portion from the plate-shaped surface.

  Conventionally, a surface light source device including two light guides is known (Patent Document 1). This surface light source device includes two light guide parts, a first light guide part and a second light guide part, which are divided into substantially the same dimensions by a slit formed in a substantially central part of one light guide plate. Prepare. And each of the 1st light guide part and the 2nd light guide part has guided the light from a light source to the whole surface.

JP 2009-267983 A

  However, in the surface light source device of Patent Document 1, when the first light guide unit and the second light guide unit emit light at the same time, light leaks from the respective end portions of the two light guide units. . The leaked light is incident on the respective light guides to mix each other's light. Thereby, there is a possibility that light of an unintended color at the time of design may be emitted from the surface light source device.

  An object of the present invention is to provide a surface light source device that has a plurality of light guides and can reduce mixing of light even when different light is guided by adjacent light guides. .

  The present invention comprises a plurality of light guide portions that are formed in a plate shape and emit light incident from the outside to the end portion from the plate surface, and a sheet-like semi-translucent member having semi-translucency, A plurality of light guides are arranged side by side, and the semi-translucent member passes between one light guide part and the other light guide part of the adjacent light guide parts among the plurality of light guide parts, It arrange | positions so that the front surface of one light guide part and the rear surface of said other light guide part may be covered.

  According to the present invention, the semi-transparent member is disposed so as to cover the front surface of one light guide portion and the rear surface of the other light guide portion among the adjacent light guide portions. At this time, the translucent member passes between one light guide and the other light guide. That is, the semi-translucent member is located between the end of one light guide and the end of the other light guide.

  Thereby, the light which mutually leaks from the edge part of each light guide part of one light guide part and the other light guide part can be reduced with a semi-transmissive member. As described above, even when a plurality of light guides are provided and different light is guided by the adjacent light guides, mixing of the lights can be reduced.

  In addition, since the semi-transparent member has semi-translucency, light emitted from the front surface of one light guide unit or the rear surface of the other light guide unit is not completely shielded, and the light intensity is Reduce. That is, the light emitted from these light guides can be emitted to the outside. At this time, in the case where light is emitted from the entire region of the surface of the light guide unit, the semi-translucent member is disposed so as to cover the front surface thereof, so that the light intensity of the semi-translucent member is increased. Reduction can be made uniform over substantially the entire area of the surface of the light guide.

  In addition, when the interval between adjacent light guides is narrow, the member for reducing or shielding the light leaking from each other is arranged only between the light guides without covering the surface of each light guide. It is necessary to significantly reduce the size of the member to be formed, and the arrangement itself may be difficult. Even when the interval between the adjacent light guide parts is narrow, if the semi-transparent member is arranged as in the present invention, the semi-transparent member has a thickness between the light guide parts. What is necessary is just to assemble | attach so that a translucent member may be inserted between each light guide part, and what is necessary is just below a space | interval. For this reason, the manufacturing cost of the said surface light source device can be reduced.

  In the present invention, it is preferable that at least a part of the region has translucency, includes a cover that covers the plate surface, and the transmittance of the part of the region is adjusted. The light intensity of the light that has passed through the semi-transparent member is reduced compared to the light emitted from one light guide. Thereby, for example, when the luminous intensity of the light emitted from one light guide unit and the other light guide unit is the same, the region corresponding to one light guide unit in the region of the cover and the other There is a possibility that the brightness differs from the region corresponding to the light guide. At this time, if the luminance setting is different from that required for the surface light source device, the luminance needs to be adjusted. The brightness of each area of the cover can be adjusted by adjusting the transmittance of the cover.

The figure which shows the structure of the surface light source device of 1st Embodiment of this invention. (A) is a figure which shows the light-guide plate and smoke sheet of the surface light source device of FIG. 1, (b) is the II-II line end view of (a). The figure which shows the structure of the surface light source device of 2nd Embodiment. (A) is a figure which shows the structure of the surface light source device of 3rd Embodiment, (b) is a figure which shows the structure of the surface light source device of 4th Embodiment.

[First Embodiment]
A surface light source device according to a first embodiment of the present invention will be described. The surface light source device 1 of the present embodiment is used for small devices such as mobile phones. The surface light source device 1 may be used for any device or apparatus.

  As shown in FIG. 1, the surface light source device 1 includes a black sheet 2, a light source 3, a light guide plate 4, a smoke sheet 5, and a cover 6.

  The black sheet 2 is formed in a sheet shape, and the entire surface is black. The black sheet 2 is provided to make the background color of the surface light source device 1 black. Note that the color of the black sheet 2 is appropriately changed according to the background color set according to the merchantability of the surface light source device 1 or the like. Further, the black sheet 2 may be omitted.

  As shown in FIGS. 1 and 2, the light source 3 includes a first light emitting diode 31 and a second light emitting diode 32. The first light emitting diode 31 is a white diode, and the second light emitting diode 32 is a red diode. Note that these two light emitting diodes 31 and 32 have their emission colors set according to the merchantability of the surface light source device 1, and are not limited to those of the present embodiment, and may be other colors. Further, the light source 3 may be constituted by other light emitters or the like instead of the light emitting diodes. The first light emitting diode 31 and the second light emitting diode 32 are mounted on the mounting substrate 30.

  The mounting board 30 is electrically connected by a connector or the like to a driving board (not shown) on which an electronic circuit for driving the two light emitting diodes 31 and 32 is mounted. The mounting board 30 controls turning on and off of the first light emitting diode 31 and the second light emitting diode 32 based on an external signal or the like.

  The light guide plate 4 is made of a single rectangular plate made of highly transparent acrylic resin. The light guide plate 4 may be made of urethane, polycarbonate, silicon, or the like as long as it has high translucency. The black sheet 2 is formed so that the size thereof is substantially the same as that of the light guide plate 4. The light guide plate 4 has a linear shape with a length slightly shorter than the length in the longitudinal direction of the light guide plate 4 from the one end portion in the short direction toward the other end side in the center portion in the short direction. The slit 4a is formed.

  The light guide plate 4 is divided into two regions of a first light guide part 41 and a second light guide part 42 by a slit 4a. One end of the first light guide 41 is divided from one end of the second light guide 42 by the slit 4 a, and the other end is connected to the other end of the second light guide 42. Thus, the 1st light guide part 41 and the 2nd light guide part 42 are arrange | positioned adjacently.

  The light source 3 is disposed adjacent to the end portions 41a and 42a where the first light guide portion 41 and the second light guide portion 42 are divided from each other. Specifically, the first light emitting diode 31 is disposed adjacent to the end portion of the first light guide portion 41 (hereinafter, this end portion is referred to as a “first incident port”) 41 a, and the second light emitting diode 32 is the first light emitting diode 32. 2 The light guide portion 42 is disposed adjacent to the end portion (hereinafter, this end portion is referred to as a “second incident port”) 42 a.

  Accordingly, when the first light emitting diode 31 is turned on, the light is substantially totally reflected by the end portion or the surface portion of the first light guide portion 41, and the entire traveling direction is the longitudinal direction of the first light guide portion 41. Light is guided to the first light guide 41. Similarly, when the second light emitting diode 32 is turned on, the light is almost totally reflected by the end portion or the surface portion of the second light guide portion 42, and the overall traveling direction is the longitudinal direction of the second light guide portion 42. Light is guided to the second light guide 42.

  Here, each of the 1st light guide part 41 and the 2nd light guide part 42 is equivalent to the light guide part in this invention. Further, “the first light guide portion 41 and the second light guide portion 42 are divided by the slit 4a and arranged adjacent to each other” means that “the plurality of light guide portions are arranged in parallel” in the present invention. It corresponds to that.

  The light guide plate 4 (the first light guide unit 41 and the second light guide unit 42) is disposed so that the rear surface thereof is in contact with the front surface of the black sheet 2. Hereinafter, the rear surface of the first light guide 41 is referred to as a first rear surface 412, and the rear surface of the second light guide 42 is referred to as a second rear surface 422. Further, the surface (that is, the front surface) opposite to the first rear surface 412 of the first light guide portion 41 is referred to as a first front surface 411, and the surface that is opposite to the second rear surface 422 of the second light guide portion 42 (that is, front surface). Is referred to as a second front surface 421.

  Each of the first light guide portion 41 and the second light guide portion 42 was guided to almost the entire surface from the first incident port 41a or the second incident port 42a toward the opposite side (end). A large number of reflecting portions (not shown) that reflect light toward the first front surface 411 or the second front surface 421 are provided. The reflection unit can use various methods generally applied to the light guide plate of the so-called edge light type surface light source device as in this embodiment. In this method, for example, as the reflecting portion, it is known to form irregularities on the acrylic surface or to print reflective dots with white ink or the like on the acrylic surface.

  Thereby, a part of the light incident from the first incident port 41a or the second incident port 42a is reflected by the multiple reflecting portions and is emitted toward the first front surface 411 or the second front surface 421. Therefore, when the first light emitting diode 31 is lit, the light by the lighting guided by the first light guide 41 is emitted from almost the entire front surface 411. Similarly, when the second light emitting diode 32 is lit, the light by the light guided by the second light guide 42 is emitted from almost the entire surface of the second front surface 421.

  Here, the first front surface 411 and the second front surface 421 correspond to the “plate surface” in the present invention. Further, as described above, the first light guide portion 41 and the second light guide portion 42 “emits light from the first front surface 411 or the second front surface 421 by the reflection portion”. This corresponds to “light emitted from the outside to the end portion is emitted from the plate surface”.

  The smoke sheet 5 is a sheet in which black PET (polyethylene terephthalate) having semi-translucency is formed in a rectangular sheet shape. Here, the semi-light-transmitting property means light-transmitting properties as well as light-shielding properties. In the present embodiment, the smoke sheet 5 has a transmissivity (in this specification, the transmissivity indicates a ratio of transmitting light) of 50% (luminous intensity) so as to have semi-translucency. Is halved). That is, when light enters one surface of the smoke sheet 5 and is emitted from the other surface, the light intensity is reduced to some extent by the smoke sheet 5 (halved in this embodiment) and emitted. Note that the transmittance of the smoke sheet 5 is not limited to 50%, but may be set to a suitable value (for example, 20% or 80%) according to the commercial characteristics of the surface light source device 1.

  The length of the smoke sheet 5 in the longitudinal direction is set slightly shorter than the length of the slit 4a. The smoke sheet 5 passes between the first light guide unit 41 and the second light guide unit 42, and passes through the rear surface (first rear surface 412) of the first light guide unit 41 and the front surface (first of the second light guide unit 42). 2 is arranged so as to cover almost the entire area with the front surface 421).

  Here, the smoke sheet 5 corresponds to the “semi-transmissive member” in the present invention. Further, “the smoke sheet 5 is arranged as described above” in the present invention “the translucent member is the one light guide portion of the adjacent light guide portions among the plurality of light guide portions. And the other light guide unit, and is disposed so as to cover the front surface of one light guide unit and the rear surface of the other light guide unit.

  The light guided by the first light guide 41 is almost totally reflected by the end or the surface of the first light guide 41. However, there is a slight amount of light that is transmitted without being reflected by the end portion or the surface portion of the first light guide portion 41 (hereinafter, light that is transmitted without being reflected in this way is referred to as “leakage light”). At this time, of the light guided by the first light guide part 41, the wall part on the slit 4a side (that is, the wall part facing the second light guide part 42; hereinafter referred to as “first wall part”) 41b. Light (hereinafter referred to as “first leakage light”) from the wall 4 on the slit 4a side of the second light guide 42 (ie, the wall facing the first light guide 41. Hereinafter, “second wall”). May be incident on 42b). Then, the white light of the first leakage light (the light emission color of the first light emitting diode 31) is incident on the second light guide 42, and the white light is mixed with the red light from the second front surface 421. There is a risk of light being emitted.

  The same applies to the light guided by the second light guide part 42, and out of the guided light, leaked light from the second wall part 42 b (hereinafter referred to as “second leaked light”). ) May enter the first wall 41b. Then, the red light of the second leakage light (the light emission color of the second light emitting diode 32) is incident on the first light guide 41, and the red light is mixed with the white light from the first front surface 411. There is a risk of light being emitted.

  However, as described above, the smoke sheet 5 is disposed so as to pass between the first light guide portion 41 and the second light guide portion 42. For this reason, each of the first leakage light and the second leakage light is reduced when passing through the smoke sheet 5. That is, by arranging the smoke sheet 5 so as to pass between the first light guide part 41 and the second light guide part 42, the intensity of the first leaked light incident on the second wall part 42 b is changed to the smoke sheet 5. Can be reduced as compared with the conventional one in which the smoke sheet 5 is not disposed, and the luminous intensity of the second leakage light incident on the first wall portion 41b can be reduced as compared with the conventional one in which the smoke sheet 5 is not disposed.

  The cover 6 is formed in a rectangular plate shape. The size of the cover 6 is larger than that of the light guide plate 4. The cover 6 is made of a synthetic resin having high translucency, and the surface thereof is black coated so as to substantially block light. The rear surface of the cover 6 is disposed on the front surface (first front surface 411 and second front surface 421) side of the light guide plate 4 (first light guide unit 41 and second light guide unit 42). The surface light source device 1 is assumed to be seen from the front surface of the cover 6 (surface opposite to the rear surface of the cover 6).

  Hereinafter, a region corresponding to the first front surface 411 in the surface of the cover 6 is referred to as a first region, and a region corresponding to the second front surface 421 in the surface of the cover 6 is referred to as a second region. As shown in FIG. 1, a logo portion (hereinafter referred to as “first logo portion”) in which the front surface and the rear surface of the first region of the cover 6 are not painted black in a shape indicating a character string “ABC”. 61) is formed. In addition, a logo portion (hereinafter referred to as a “second logo portion”) 62 that is not painted black in a shape indicating a character string “DEF” is formed on the front surface and the rear surface of the second region of the cover 6. Has been.

  Since the 1st logo part 61 and the 2nd logo part 62 are not painted black, the surface of the synthetic resin which has high translucency is exposed. That is, the cover 6 receives and emits light only from the first logo portion 61 and the second logo portion 62. Specifically, in the cover 6, the light emitted from the first front surface 411 is emitted only from the first logo portion 61, and the light emitted from the second front surface 421 is emitted only from the second logo portion 62.

  Therefore, when viewed from the front of the cover 6, when the first light emitting diode 31 is lit, the character string “ABC” formed in the first logo portion 61 appears to shine white, When the two light emitting diodes 32 are lit, the character string “DEF” formed in the second logo portion 62 appears to shine red.

  The character strings formed in the first logo portion 61 and the second logo portion 62 are appropriately set according to the application of the surface light source device 1. The shape of the logo portion (61 and 62) may be any shape such as a picture or a symbol in addition to expressing a character string.

  As described above, in the present embodiment, the smoke sheet 5 is disposed in the slit 4 a that divides the first light guide portion 41 and the second light guide portion 42. Specifically, as described above, the smoke sheet 5 passes between the first light guide unit 41 and the second light guide unit 42 and passes between the rear surface of the first light guide unit 41 and the second light guide unit 42. It is arranged so as to cover almost the entire area with the front surface.

  Therefore, the smoke sheet 5 reduces the intensity of the red second leakage light incident on the first wall portion 41b and hence the first light guide portion 41, and also reduces the second wall portion 42b and the second light guide portion 42. The luminous intensity of the incident white first leakage light is reduced. Therefore, the smoke sheet 5 can reduce the influence of the red second leakage light on the light emitted from the first logo portion 61 (white first light emitting diode 31), and the light emitted from the second logo portion 62. It is possible to reduce the influence of white first leakage light on (red second light emitting diode 32).

  As described above, the light guide unit 41 includes the first light guide unit 41 and the second light guide unit 42 which are a plurality of (two) light guide units, and different light (first light emitting diodes) in the adjacent light guide units (41, 42). 31 white light and red light of the second light emitting diode 32) can be mixed with each other.

  In addition, the smoke sheet 5 is disposed so as to cover the rear surface of the first light guide portion 41 and the front surface of the second light guide portion 42 (that is, cover substantially the entire surface of these surfaces).

  The width of the slit 4 a provided in the light guide plate 4 is set according to the positional relationship between the first logo portion 61 and the second logo portion 62. From the viewpoint of design, the surface light source device 1 is often desired to provide a plurality of logo portions that emit light of different colors in close proximity.

  Accordingly, in order to meet such a demand, the slit 4a is formed to be thin. Even when the slit 4a is formed thin, if the smoke sheet 5 is formed thinner than the width of the slit 4a, the smoke sheet 5 is passed through the slit 4a (the first light guide 41 and the second guide). It is possible to pass between the optical part 42).

  Therefore, the smoke sheet 5 passes between the first light guide 41 and the second light guide 42, and the rear surface (first rear surface 412) of the first light guide 41 and the front surface of the second light guide 42. It is only necessary to arrange so as to cover almost the entire area with (the second front surface 421). In other words, the smoke sheet 5 is sandwiched between the rear surface of the first light guide unit 41 and the front surface of the second light guide unit 42.

  When arranged in this way, even if the width of the slit 4a is set to be very small, it is only necessary to pass the smoke sheet 5 so as to be inserted into the slit 4a. Cost can be reduced.

  In addition, the smoke sheet 5 is usually (a sheet made of PET in the present embodiment) and can be formed very thin (for example, 0.05 mm to 1 mm). For this reason, it is very unlikely that the thickness of the smoke sheet 5 is an obstacle to providing a plurality of logo portions that emit light of different colors in close proximity, and various demands regarding the arrangement of the plurality of logo portions. Can respond.

  Further, the smoke sheet 5 is disposed so as to cover almost the entire area of the front surface (second front surface 421) of the second light guide unit 42. Thereby, the reduction of the luminous intensity of the light emitted from the second front surface 421 can be made uniform in the region, and an extreme bias can be prevented from occurring in the luminous intensity of the light emitted from the second logo portion 62. Note that the smoke sheet 5 does not necessarily need to cover almost the entire area of the second front surface 421. For example, in the present embodiment, a portion corresponding to the second logo portion 62 may be covered.

  In addition, the smoke sheet 5 does not shield light (almost completely) and has semi-translucency. This is because in the present embodiment, the light emitted from the second front surface 421 is desired to be emitted upward in FIG. 1 through the smoke sheet 5 and the cover 6. Therefore, instead of the smoke sheet 5 of the present embodiment, when using a sheet that shields light (substantially completely) (hereinafter referred to as “shielding sheet”), like the smoke sheet 5 of the present embodiment, The shielding sheet cannot be disposed so as to cover the second front surface 421.

  In particular, when the distance between the first logo portion 61 and the second logo portion 62 is narrow (that is, when the width of the slit 4a needs to be reduced), the shielding sheet covers the second front surface 421. It is necessary to arrange only between the slits 4a. When the width of the slit 4a is narrow, it is difficult to require a strict arrangement such that the slit 4a is arranged only between the slits 4a in this way, and the manufacturing cost increases even if it can be realized.

  For this reason, since the smoke sheet 5 has semi-translucency as in the present embodiment, it is not necessary to strictly arrange the smoke sheet 5, and the manufacturing cost of the surface light source device 1 can be reduced.

  In the present embodiment, the first logo portion 61 and the second logo portion 62 are not painted black, and the surface of the synthetic resin having high translucency is exposed. Alternatively, the first logo portion 61 and the second logo portion 62 may be configured to be shielded somewhat. Furthermore, when comprised in this way, you may comprise so that the light-shielding property of the 1st logo part 61 and the 2nd logo part 62 may differ. Usually, the luminance of the first logo portion 61 and the second logo portion 62 is set in consideration of the design property or the commercial property of the surface light source device 10.

  For example, the light intensity of the light emitted from the second front surface 421 changes by passing through the smoke sheet 5, and the brightness of the second logo portion 62 is lower than that of the light without the smoke sheet 5. Furthermore, the light intensity emitted from the first front surface 411 and the smoke sheet 5 changes through the cover 6, and the brightness of the first logo portion 61 and the second logo portion 62 changes.

  For this reason, when the luminance of the first logo portion 61 and the second logo portion 62 is not intended, the first logo of the cover 6 is set so that the respective luminances are required. The transmittance of the part 61 and the second logo part 62 is set as appropriate.

  In addition, considering the uniformity or toning of light emitted from the first logo portion 61 and the second logo portion 62, the transmittance of the first logo portion 61 and the second logo portion 62 is partially different. It may be changed. The transmittance can be set by using various generally known methods such as adjusting the darkness of the coating.

  Here, “the first logo portion 61 and the second logo portion 62 of the cover 6” in the present embodiment corresponds to “at least a partial region” in the present invention. In addition, “as described above, the transmittance of the first logo portion 61 and the second logo portion 62 is set” means that “the transmittance of the partial area is adjusted” in the present invention. Equivalent to.

[Second Embodiment]
Next, the surface light source device of 2nd Embodiment of this invention is demonstrated with reference to FIG. The surface light source device 10 of the present embodiment differs from the surface light source device 1 of the first embodiment in the following points. In the surface light source device 1 according to the first embodiment, logo portions (character strings “ABC” and “DEF”) for causing the light to shine are provided on the cover 6 as a first logo portion 61 and a second logo portion 62. In the first embodiment, the first light guide portion 41 and the second light guide portion 42 are provided with a large number of reflecting portions on the entire surface, and light is emitted from almost the entire front surface 411 and the second front surface 421. ing.

  On the other hand, in the surface light source device 10 of the second embodiment, the first light guide unit 41 and the second light guide unit 42 are provided with logo portions (character strings “ABC” and “DEF”) for causing the light to shine. . Specifically, in the second embodiment, the light guided from the first incident port 41 a is reflected toward the first front surface 411 so that the first light guide 41 emits light in the shape of the character string “ABC”. A plurality of reflecting portions (hereinafter referred to as “first logo portion”) 413, and the second light incident portion 42 shines as the shape of the second logo portion (character string “DEF”). A plurality of reflecting portions (hereinafter referred to as “second logo portion”) 423 that reflects light guided from the opening 42 a toward the second front surface 421 is provided.

  As described above, in the second embodiment, unlike the first embodiment, the reflective portion is not arranged so as to emit light from almost the entire surface of the first light guide portion 41 and the second light guide portion 42, and the character is Reflecting portions (first logo portion 413 and second logo portion 423) are provided only to shine as the shape of the rows (“ABC” and “DEF”). Such reflective portions (the first logo portion 413 and the second logo portion 423) are generally applied to the light guide plate of a so-called edge light type surface light source device, such as providing reflective dots, as in the first embodiment. A variety of methods can be used.

  Thereby, a part of the light incident from the first incident port 41 a or the second incident port 42 a is reflected toward the first front surface 411 or the second front surface 421 by being reflected by the first logo portion 413. Therefore, when the first light-emitting diode 31 is lit, the light from the lighting guided by the first light guide unit 41 is light that forms the character string “ABC” from the first front surface 411 (first front surface). Light that can be recognized as shining in the shape of the character string “ABC” when 411 is viewed) is emitted. Similarly, when the second light emitting diode 32 is lit, the light by the lighting guided by the second light guide unit 42 is light that forms the character string “DEF” from the second front surface 421 (second Light that can be recognized as shining in the shape of the character string “DEF” when the front surface 421 is viewed is emitted.

  An area (hereinafter referred to as “first area”) 611 corresponding to the first logo part 413 and an area (hereinafter referred to as “second area”) 621 corresponding to the second logo part 423 of the cover 6 are transparent. It is painted so as to have light properties (except for the first region 611 and the second region 621, which is painted so as not to have translucency). That is, in the second embodiment, the cover 6 emits light only from the first region 611 and the second region 621. Specifically, the light emitted from the first logo portion 413 is emitted from the first region 611, and the light emitted from the second logo portion 423 is emitted from the second region 621. As a result, white light shaped as the character string “ABC” is emitted from the first area 611, and red light shaped as the character string “DEF” is emitted from the second area 621.

  Even when the surface light source device 10 is configured as described above, the smoke sheet 5 is disposed so as to pass between the first light guide 41 and the second light guide 42. For this reason, similarly to the first embodiment, a plurality of (two) light guides, the first light guide part 41 and the second light guide part 42, are provided, and adjacent light guide parts (41, 42). Even when different lights (white light of the first light-emitting diode 31 and red light of the second light-emitting diode 32) are guided, the effect of the present invention that the mixing of the light of each other can be reduced is obtained. .

  Note that the transmittances of the first region 611 and the second region 621 are set in consideration of the design property or the commercial property of the surface light source device 10. For example, when the light emitted from the second logo portion 423 passes through the smoke sheet 5, the light intensity thereof changes, and the luminance of the area corresponding to the second logo portion 423 of the smoke sheet 5 decreases. When the brightness of the area and the brightness of the first logo portion 413 are not intended, the transmittance of the first area 611 and the second area 621 so that the respective brightness becomes the required brightness. Set.

  Such a request is, for example, a request such that the first logo part 413 and the second logo part 423 have the same brightness, or the first logo part 413 has a higher brightness than the second logo part 423. (Or vice versa). Even in such a case, it is possible to meet the request by appropriately setting the transmittances of the first region 611 and the second region 621.

  Further, in consideration of the uniformity or toning of the light emitted from the first region 611 and the second region 621, the transmittance of the first region 611 and the second region 621 may be changed to be partially different. Good. The transmittance can be set by using various generally known methods such as adjusting the darkness of the coating.

  Further, in the present embodiment, the first region 611 and the second region 621 are painted so as to have a transmittance, but are painted in consideration of the design property or the commercial property of the surface light source device 10. Instead, the surface of the synthetic resin having high translucency may be exposed.

  Here, “the first region 611 and the second region 621 of the cover 6” in the present embodiment corresponds to “at least a part of the region” in the present invention. Further, “the transmittance of the first region 611 and the second region 621 is appropriately set as described above” corresponds to “the transmittance of the partial region is adjusted” in the present invention. .

[Third Embodiment]
Next, a surface light source device 11 according to a third embodiment of the present invention will be described with reference to FIG. The surface light source device 11 of the present embodiment differs from the surface light source device 1 of the first embodiment in the following points. The surface light source device 1 of the first embodiment includes the two light guide portions 41 and 42, whereas the surface light source device 11 of the third embodiment includes the five light guide portions 41 to 45. That is, the light guide plate 4 is divided into five light guide parts 41 to 45 of the first light guide part 41 to the fifth light guide part 45 by the four slits 4a to 4d of the first slit 4a to the fourth slit 4d. ing.

  And as the light source 3, adjacent to each entrance 41a-45a of the 1st light guide part 41-the 5th light guide part 45, five light emitting diodes 31- 1 of the 1st light emitting diode 31-the 5th light emitting diode 35 are shown. 35 is arranged. Thereby, each of the 1st light guide part 41-the 5th light guide part 45 transmits the light when a corresponding light emitting diode (31-35) lights up from the entrance (41a-45a) to the other end. The light is guided toward the part.

  Here, in the present embodiment, the first light emitting diode 31, the third light emitting diode 33, and the fifth light emitting diode 35 emit white light, and the second light emitting diode 32 and the fourth light emitting diode 34 emit red light. To do. Note that the colors of the five light-emitting diodes are set according to the merchantability of the surface light source device 11, and for example, all five may be set to different colors.

  Similar to the first embodiment, the cover 6 is made of a synthetic resin having high translucency, and the surface thereof is painted black so as to substantially block light. The cover 6 is provided with five logo parts 61 to 65 including a first logo part 61 to a fifth logo part 65.

  The first logo portion 61 is not painted black in the shape of the character string “ABC”. The first light guide 41 guides the light emitted from the first light emitting diode 31 so that the entire front surface emits light. Accordingly, when the first light emitting diode 31 emits light, the first logo portion 61 looks as if the character string is shining white. The second logo part 62 is not painted black in the shape of the character string “DEF”. The second light guide unit 42 guides the light emitted by the second light emitting diode 32 so that the entire front surface emits light. Therefore, when the second light emitting diode 32 emits light, the second logo portion 62 looks like the character string glows red.

  The third logo portion 63 is not painted black in the shape of the character string “GHI”. The third light guide 43 guides the light emitted by the third light emitting diode 33 so that the entire front surface emits light. Accordingly, when the third light emitting diode 33 emits light, the third logo portion 63 looks like the character string glows white. The fourth logo portion 64 is not painted black on the shape of the character string “JKL”. The fourth light guide 44 guides the light emitted by the fourth light emitting diode 34 so that the entire front surface emits light. Accordingly, when the fourth light emitting diode 34 emits light, the fourth logo portion 64 looks like the character string glows red.

  The fifth logo portion 65 is not painted black on the shape of the character string “MNL”. The fifth light guide unit 45 guides the light emitted by the fifth light emitting diode 35, so that the entire front surface emits light. Accordingly, when the fifth light emitting diode 35 emits light, the fifth logo portion 65 looks as if the character string is shining white.

  The smoke sheet 5 includes a rear surface of the first light guide 41, a front surface of the second light guide 42, a rear surface of the third light guide 43, a front surface of the fourth light guide 44, and a rear surface of the fifth light guide 45. Are arranged so as to cover each.

  Specifically, the smoke sheet 5 passes between the first light guide unit 41 and the second light guide unit 42 which are adjacent light guide units among the plurality of light guide units, and passes through the first light guide unit 41. It arrange | positions so that a rear surface and the front surface of the 2nd light guide part 42 may be covered. As a result, the leakage light between the first light guide 41 and the second light guide 42 is reduced by the smoke sheet 5, and the mutual light (white light and red light) of the two light guides 41 and 42 is reduced. Light) can be reduced. The smoke sheet 5 passes between the second light guide part 42 and the third light guide part 43 which are adjacent light guide parts among the plurality of light guide parts, and the front surface of the second light guide part 42 and the third light guide part 43. It arrange | positions so that the rear surface of the light guide part 43 may be covered. Thereby, the leakage light between the second light guide part 42 and the third light guide part 43 is reduced by the smoke sheet 5, and the mutual light (red light and white light) of the two light guide parts 42, 43 is reduced. Light) can be reduced.

  The smoke sheet 5 passes between the third light guide part 43 and the fourth light guide part 44 which are adjacent light guide parts among the plurality of light guide parts, and the rear surface of the third light guide part 43 and the fourth light guide part 44. It arrange | positions so that the front surface of the light guide part 44 may be covered. Thereby, the leakage light between the third light guide 43 and the fourth light guide 44 is reduced by the smoke sheet 5, and the light (white light and red light) of the two light guides 43 and 44 is reduced. Light) can be reduced. The smoke sheet 5 passes between the fourth light guide part 44 and the fifth light guide part 45 which are adjacent light guide parts among the plurality of light guide parts, and the front surface of the fourth light guide part 44 and the fifth light guide part 44. It arrange | positions so that the rear surface of the light guide part 45 may be covered. Thereby, the leakage light between the fourth light guide 44 and the fifth light guide 45 is reduced by the smoke sheet 5, and the mutual light (red light and white light) of the two light guides 44 and 45 is reduced. Light) can be reduced.

  As described above, the third embodiment also includes the first light guide part 41 to the fifth light guide part 45 which are a plurality of (five) light guide parts, and the adjacent light guide parts (41 and 42). , 42 and 43, 43 and 44, and 44 and 45), the smoke sheet 5 can reduce the mixing of light with each other.

[Fourth Embodiment]
Next, a surface light source device according to a fourth embodiment of the present invention will be described with reference to FIG. Hereinafter, differences between the surface light source device 12 of the fourth embodiment and the surface light source device 11 of the third embodiment will be described.

  In the fourth embodiment, the first light emitting diode 31, the second light emitting diode 32, the fourth light emitting diode 34, and the fifth light emitting diode 35 emit white light, and only the third light emitting diode 33 emits red light. To do. Accordingly, the entire surface of the first light guide 41, the second light guide 42, the fourth light guide 44, and the fifth light guide 45 emits white light, and the third light guide 43 has a red surface. Flashes.

  That is, in the present embodiment, the two light guide portions 42 and 44 of the second light guide portion 42 and the fourth light guide portion 44 arranged on both sides of the third light guide portion 43, and the third light guide portion. What is necessary is just to reduce the leak light between 43.

  As in this embodiment, the five light guide portions 41 to 45 of the first light guide portion 41 to the fifth light guide portion 45 are formed, but the light guided by the adjacent light guide portions has the same color. In this case, in the present invention, these light guide parts are set as one light guide part. This is because, in the present invention, the adjacent light guides that guide the light of the same color have the same color even when the leaked lights are incident on each other. There is no. In such adjacent light guide portions, it is not necessary to arrange the smoke sheet 5 therebetween.

  Thus, the “light guide” in the present invention is a case where the leakage light does not affect each other due to the same color, etc., even when the light guide is actually divided into a plurality of light guides. Is “one light guide”. Hereinafter, the light guides combined into one in this way are referred to as “virtual light guides”. Therefore, “adjacent light guides” in the present invention means “adjacent virtual light guides”.

  In the present embodiment, there are three virtual light guides (first virtual light guide to third virtual light guide). The first virtual light guide unit is a first light guide unit 41 and a second light guide unit 42 that are arranged next to each other and emit white light from each other, and the second virtual light guide unit emits red light. It is the 3rd light guide part 43 to radiate | emit, and a 3rd virtual light guide part is the 4th light guide part 44 and the 5th light guide part 45 which radiate | emit white light mutually while arrange | positioning adjacently.

  The first virtual light guide unit and the second virtual light guide unit are arranged adjacent to each other, and the second virtual light guide unit and the third virtual light guide unit are arranged adjacent to each other.

  Accordingly, the smoke sheet 5 includes the front surfaces of the first light guide 41 and the second light guide 42 (first virtual light guide), the rear surface of the third light guide 43 (second virtual light guide), and the first It arrange | positions so that the front surface of the 4 light guide part 44 and the 5th light guide part 45 (3rd virtual light guide part) may each be covered.

  Specifically, the smoke sheet 5 is a second light guide 42 (first virtual guide) that is an adjacent light guide (virtual light guide) among a plurality of light guides (virtual light guides). A portion of the light section) and the third light guide section 43 (second virtual light guide section), and passes through the first light guide section 41 and the second light guide section 42 (first virtual light guide section). It arrange | positions so that a front surface and the rear surface of the 3rd light guide part 43 (2nd virtual light guide part) may be covered. Thereby, the mutual leakage light is reduced by the smoke sheet 5 between the 2nd light guide part 42 (a part of 1st virtual light guide part) and the 3rd light guide part 43 (2nd virtual light guide part). The mixing of the light (white light and red light) of the two light guides 42 and 43 can be reduced.

  The smoke sheet 5 includes a third light guide 43 (second virtual light guide) that is an adjacent light guide (virtual light guide) among a plurality of light guides (virtual light guide). Passing between the fourth light guide 44 (a part of the third virtual light guide), the rear surface of the third light guide 43 (second virtual light guide), the fourth light guide 44 and the fifth light guide. It arrange | positions so that the front surface of the light guide part 45 (3rd virtual light guide part) may be covered. Thereby, the leakage light between the third light guide 43 (second virtual light guide) and the fourth light guide 44 (part of the third virtual light guide) is reduced by the smoke sheet 5. The mixing of the mutual light (red light and white light) of the two light guide portions 43 and 44 can be reduced.

  As described above, the fourth embodiment also includes a plurality of (three) (virtual) light guides (“41, 42”, “43”, and “44, 45”), which are adjacent to each other. Even when different light is guided by the (virtual) light guides (“41, 42” and “43”, “43” and “44, 45”), the smoke sheet 5 allows the mutual light to pass. Can be reduced.

  In the first to fourth embodiments, the plurality of light guides are configured to be connected at one end thereof, but the present invention is not limited thereto, and each of the plurality of light guides is an independent member. It may be formed. That is, for example, taking the first embodiment as an example, the end portions of the first light guide portion 41 and the second light guide portion 42 opposite to the entrance ports (the first entrance port 41a and the second entrance port 42a) are What is not connected may be sufficient.

  Even in such a case, if a semi-translucent member such as the smoke sheet 5 is disposed so as to pass between the plurality of light guides, the light leaked from each of the plurality of light guides Even if it is incident, the light intensity of the leaked light is reduced. Therefore, even if it has a plurality of light guides and different light is guided by the adjacent light guides, the effect of the present invention that the mixing of the light of each other can be reduced is obtained.

  Further, as shown in the first to fourth embodiments, the number of light guides may be any number as long as it is two or more. In each of the first to fourth embodiments, each light guide unit guides light from one light emitting diode. However, the present invention is not limited thereto, and each light guide unit includes a plurality of light emitting diodes (or other light emitting diodes). Body) light may be guided.

  In the first to fourth embodiments, the light guide unit is configured to emit light from the front surface and not emit light from the rear surface. However, the present invention is not limited to this, and the light guide unit may be configured to emit light from both the front surface and the rear surface.

  Moreover, in the 1st-4th embodiment, although the smoke sheet 5 which is a translucent member was arrange | positioned so that the front surface or rear surface of each light guide part might be covered, the surface which the said smoke sheet 5 covers is, It may be either as long as the adjacent light guides are on the opposite side. That is, for example, in the first embodiment, if the smoke sheet 5 is disposed between the first light guide 41 and the second light guide 42, the front surface of the first light guide 41 (first 1 front surface 411) and the rear surface (second rear surface 422) of the second light guide 42 may be covered.

  Moreover, each light emitting diode used for the light source 3 shown in the first to fourth embodiments has a light color fixed to white or red. As a requirement for the surface light source device, not only the light color is fixed, but there is a case where it is desired to change the light color according to the setting or the time change. In such a case, for example, a three-color light emitting diode may be used as a light source of light guided by each light guide. Even in such a case, the effect of the present invention that the mixing of different light can be reduced is obtained.

  DESCRIPTION OF SYMBOLS 1 ... Surface light source device (surface light source device of 1st Embodiment), 10 ... Surface light source device (surface light source device of 2nd Embodiment), 11 ... Surface light source device (surface light source device of 3rd Embodiment), 12 ... Surface light source device (surface light source device of the fourth embodiment), 4... Light guide plate (a plurality of light guide portions), 41... First light guide portion (light guide portion), 411. ... 1st rear surface (rear surface of the other light guide part), 42 ... 2nd light guide part (light guide part), 421 ... 2nd front surface (plate surface, front surface of one light guide part), 5 ... Smoke sheet ( Semi-translucent member), 6 ... cover.

Claims (2)

A plurality of light guide portions that are formed in a plate shape and emit light from the plate surface that is incident on the end portion from the outside;
A sheet-like semi-translucent member having semi-translucency,
The plurality of light guides are juxtaposed,
The translucent member passes between one light guide portion and the other light guide portion of the adjacent light guide portions among the plurality of light guide portions, and the front surface of the one light guide portion and the other light guide portion. A surface light source device arranged to cover the rear surface of the light guide unit.   The surface light source device according to claim 1, wherein at least a part of the region has a light-transmitting property, includes a cover that covers the plate surface, and the transmittance of the part of the region is adjusted. Surface light source device.