JP5161134B2 - Light guide member and electronic device - Google Patents

Description

  The present invention relates to a suitable light guide member used for an illumination member such as an electronic device and an electronic device equipped with the light guide member.

  In recent years, in electronic devices such as mobile phones and portable information terminal devices, it has been required to improve the visibility of the display unit and / or the input unit of the electronic device in a dark place. Further, a plurality of applications are often incorporated in one electronic device, and it is desired that the display unit and / or the input unit can be easily identified for each application.

  Conventionally, as a light guide member used for illuminating an electronic device or the like, mainly a direct type system in which a light source is disposed directly under a display surface to be illuminated, and a side surface or a peripheral portion of a flat light guide plate An edge light type is known in which light is introduced from the light source to diffuse the light in the light guide plate and supplies the light to the display surface. In particular, the edge light method is widely used because the electronic device can be thinned. In the case of an edge light type light guide member, generally, for example, as disclosed in Patent Document 1, light is diffused on one wide surface of a substantially rectangular parallelepiped light guide made of a transparent plastic member or the like. In a planar light source unit for a panel having a light source close to the side surface of the light guide, a point light source is disposed close to the side edge of at least one corner of the light guide It has been known.

  On the other hand, when a plurality of applications are incorporated in one electronic device, the following light guide member has been proposed in order to easily determine the display unit and / or the input unit for each application. For example, a plurality of light emitting diodes (hereinafter referred to as LEDs) that emit different colors are arranged at desired positions on the circuit board, and two light guide plates for guiding the light of the different colors are stacked and mounted. Furthermore, in order to guide only the LED light having a desired color to each light guide plate, the end face of the light guide plate that does not need to guide the light of the LED having a desired color tone is light-shielded. In such an illuminating member, each of the light guide plate layers for guiding a desired color tone can refract and guide the light to a desired illuminating portion of the light guide plate, and illuminate the display surface above it.

JP 11-306831 A (Claims etc.)

  However, the conventional light guide member has the following problems. Today, there is a demand for further thinning of electronic equipment, and the thickness of members constituting the electronic equipment is required to be extremely thin. For this reason, in the case of an electronic device in which the display unit and / or the input unit can be identified for each application, a light-transmitting member having a thickness of 0.125 mm or more and 0.25 mm or less is suitable as the light guide plate. Moreover, the chip thickness of the illumination part of LED is 0.4 mm or more and 0.8 mm or less. In order to obtain the maximum light guide effect, it is necessary to arrange the position of the end face of the light guide plate at the highest luminance position of the LED. For this reason, when a thin light-guide plate is used, there exists a problem which cannot fully guide the light from LED. On the other hand, if the thickness of the light guide plate includes the position of the portion with the highest luminance of the LED in order to enhance the light guide effect, there is a problem that the overall thickness of the electronic device is increased. Further, it is necessary to guide only light having a desired color to each light guide plate, and it is necessary to shield an end face of the light guide plate that does not need to guide light from an LED that emits light of a specific color tone. For this reason, there also exists a problem of causing the increase of a manufacturing process, the difficulty of a process, and the raise of the manufacturing cost accompanying them.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is a thin light guide member capable of high-luminance multicolor illumination and a light guide thereof. An object of the present invention is to provide an electronic device equipped with a member.

  In order to achieve the above object, the present invention is a light guide member that is disposed opposite to a display unit or input unit to be illuminated, receives light from a plurality of light sources, guides the light into the inside, and illuminates the display unit or input unit The light guide member is formed by laminating at least two light guide plates, and each light guide plate includes a light receiving portion that receives light from a specific light source on an end surface of each light guide plate. At least one of the light guide plates is a light guide member that is bent in the thickness direction of the light guide member so that the light receiving portion of each light guide plate approaches the height of the light emission position of a specific light source.

  By setting it as the above light guide members, it becomes a thin light guide member which enables high-intensity multicolor illumination. In other words, at least one of the light guide plates is bent in the thickness direction of the light guide member so that the light receiving portion of each light guide plate approaches the height of the light emission position of the specific light source. Even if the light plate is used, the position of the light receiving portion of each light guide plate can be matched with the highest luminance position of the LED. As a result, the light from the LED can be sufficiently guided, and the electronic device equipped with the light guide member can be thinned. Moreover, since only the LED light which has a desired color can be guided to the light-receiving part of each light-guide plate, it is not necessary to light-shield the end surface of light-guide plates other than the vicinity of LED which has a desired color tone.

  In another invention, in addition to the above-described invention, at least one of the light guide plates has a cutout portion that is cut away in a direction away from the light source that does not require light guide. The light guide plates other than the two light guide plates have a convex portion bent so as to enter the cutout portion in the thickness direction of the light guide member, and the light receiving portion of the light emitting position of the light source that needs to be guided The light guide member is close to the height.

  By setting it as such a light guide member, the light from a specific light source can be received efficiently.

  In addition to the above-described invention, another invention is a light guide member having a shape in which the convex portion is gradually inclined toward the opposite direction from the opening of the notch.

  By using such a light guide member, the light guide plate can be molded without being damaged or damaged. Therefore, it is difficult for light guides to occur.

  In another invention, in addition to the above-described invention, the light guide plate is a light guide member provided with a plurality of light scattering portions inside the light receiving portion along the traveling direction of light from the light source.

  For this reason, a portion where light from the light source is insufficient or a portion where light is particularly desired to be emitted can be partially emphasized by the polarization of light.

  In another invention, in addition to the above-mentioned invention, the light scattering portion has a plurality of convex bodies that polarize received light toward the display section or the input section, and the plurality of convex bodies as the distance from the light source increases. The light guide member has a higher density.

  For this reason, the luminance variation of the light by the distance from the light source can be made uniform.

  Another invention is an electronic device in which the light guide member according to any one of claims 1 to 5 is mounted.

  For this reason, the electronic device is thin and capable of high-luminance multicolor illumination.

  According to the present invention, it is possible to provide a thin light guide member capable of high-luminance multicolor illumination and an electronic device equipped with the light guide member.

It is a perspective view which shows a part of internal structure of a mobile telephone (one form of electronic device) provided with the light guide member which concerns on embodiment of this invention. It is an expansion perspective view which expands and shows the structure of the area | region A shown with the dashed-dotted line of FIG. It is CC sectional view taken on the line of the area | region A shown in FIG. It is an expansion perspective view which expands and shows the structure of the area | region B shown by the dashed-dotted line of FIG. FIG. 6 is a cross-sectional view taken along a line DD in a region B illustrated in FIG. 4. It is a top view which shows simply the form of the light-scattering part formed in each light-guide plate main-body part of a 1st light-guide plate and a 2nd light-guide plate.

  Hereinafter, preferred embodiments of a light guide member according to the present invention and an electronic apparatus equipped with the light guide member will be described in detail with reference to the drawings. However, the present invention is not limited to the preferred embodiments described below.

  FIG. 1 is a perspective view showing a part of an internal configuration of a mobile phone (one form of electronic equipment) 1 including a light guide member 10 according to an embodiment of the present invention. FIG. 2 is an enlarged perspective view showing an enlarged configuration of a region A indicated by a one-dot chain line in FIG. FIG. 3 is a cross-sectional view taken along line CC of region A shown in FIG. FIG. 4 is an enlarged perspective view showing an enlarged configuration of a region B indicated by a one-dot chain line in FIG. FIG. 5 is a cross-sectional view taken along the line DD of the region B shown in FIG.

  As shown in FIG. 1, the mobile phone 1 includes a light guide member 10, a circuit board (hereinafter referred to as “substrate”) 2 disposed on the back surface thereof, and one end face of the light guide member 10 in the vicinity. Arranged mainly on the substrate 2 are two LEDs (one type of light source) 5a and 5b (collectively referred to as “LED5”) that emit light of different colors. In this embodiment, the LED 5a is a light source that emits red light, and the LED 5b is a light source that emits blue light. The two LEDs 5a and 5b may be arranged side by side along only one end face as shown in FIG. 1, or may be arranged on the other end face. Two or more LEDs 5 may be arranged on one end surface.

  2 and 3, the light guide member 10 includes a first light guide plate (one of the two light guide plates) 15 and a second light guide plate (of the two light guide plates). The other light guide plate 16) is laminated. The first light guide plate 15 includes a light guide plate main body portion 17 having a light scattering portion 20 and a light receiving portion (first light receiving portion) 18 provided on one end surface of the light guide plate main body portion 17. Further, the second light guide plate 16 is formed with a first cutout portion 25 cutout in a direction away from the LED 5a. The 1st light-receiving part 18 is facing LED5a at the height substantially the same as the height of the light emission part of LED5a. On the other hand, by providing the 1st notch part 25, while the end surface of the 2nd light guide plate 16 facing LED5a arrange | positioned at the board | substrate 2 leaves | separates from LED5a, the height of the end surface of the 2nd light guide plate 16 is LED5a. It faces the LED 5a at a position lower than the height of the light emitting portion. For this reason, the red light from the LED 5 a is more likely to enter the first light guide plate 15 than the second light guide plate 16.

  As shown in FIGS. 4 and 5, the second light guide plate 16 constituting the light guide member 10 is provided on the light guide plate main body portion 17 including the light scattering portion 20 and one end surface of the light guide plate main body portion 17. Light receiving portion (second light receiving portion) 19. The first light guide plate 15 that does not need to receive light from the LED 5b has a second cutout portion 26 that is cut away in a direction away from the LED 5b on the end surface facing the LED 5b, and receives light from the LED 5b. The second light guide plate 16 that needs to be formed has a convex portion 21 that is bent so as to enter the second cutout portion 26 in the thickness direction of the light guide member 10. The second light receiving portion 19 is on the end face of the convex portion 21 and faces the LED 5b at substantially the same height as the light emitting portion of the LED 5b disposed in the second cutout portion 26. The convex portion 21 has a shape that gradually inclines downward from the opening of the second cutout portion 26 in the opposite direction.

  As described above, the light guide member 10 is formed by laminating the thin plate-like first light guide plate 15 and the second light guide plate 16, and each LED 5 a is provided on each of the first light guide plate 15 and the second light guide plate 16. , 5b and the first light receiving portion 18 and the second light receiving portion 19 so as to be the same height as the light emitting portion, the first light guide plate 15 for guiding the light of the LEDs 5a, 5b and the first light guide plate 15 2 can be incident on the light guide plate 16. As a result, it is possible to reduce the thickness of the mobile phone 1 on which the light guide member 10 is mounted. Further, the first light guide plate 15 and the second light guide plate 16 can receive only light of a desired color from a plurality of light sources and guide the light into the respective interiors to illuminate the display unit or the input unit with high luminance.

  The first light guide plate 15 and the second light guide plate 16 are preferably translucent members made of polycarbonate resin (PC). However, the first light guide plate 15 and the second light guide plate 16 are made of resin other than polycarbonate resin (PC), for example, polyethylene terephthalate resin (PET), polypropylene resin (PP), polymethyl methacrylate resin (PMMA), benzyl methacrylate resin. MS resin, acrylic resin, or optically transparent resin such as cycloolefin polymer (COP) may be used. Furthermore, scattering particles for scattering light may be kneaded and dispersed in the above-described translucent resin. As the scattering particles, thin cone, silica, zirconia, dielectric polymer and the like can be suitably used. By including such scattering particles in the first light guide plate 15 and the second light guide plate 16, the light from the LEDs 5 can be uniformly guided with little luminance unevenness.

  Moreover, it is more preferable that the first light guide plate 15 and the second light guide plate 16 are formed from the flexible resin material. For this reason, since the light guide member 10 formed by laminating the first light guide plate 15 and the second light guide plate 16 can be easily processed, a display unit and / or an input unit (not shown) having a curved shape. ) Can be freely deformed and arranged. As a result, the light guide member 10 can be in close contact with the display unit or the input unit, and can be illuminated uniformly.

  Moreover, the manufacturing method of the 1st light-guide plate 15 and the 2nd light-guide plate 16 is not restrict | limited in particular, A well-known technique can be used. For example, the scattering particles are uniformly dispersed in the raw material of the transparent resin in advance, and manufactured by cast molding, extrusion molding, injection molding, press molding or the like using such a raw material.

  A suitable thickness of the first light guide plate 15 and the second light guide plate 16 is in the range of 0.05 mm to 0.3 mm, and a particularly preferable thickness is in the range of 0.1 mm to 0.2 mm. When the thickness of the first light guide plate 15 and the second light guide plate 16 is 0.05 mm or more, the first light guide plate 15 is heated when the first light guide plate 15 and the second light guide plate 16 are heated and drawn. 15 and the second light guide plate 16 can be prevented from being broken. Moreover, when the thickness of the 1st light guide plate 15 and the 2nd light guide plate 16 is 0.3 mm or less, the light guide member 10 can be made thinner.

  FIG. 6 is a plan view schematically showing the form of the light scattering portion 20 formed in each light guide plate main body portion 17 of the first light guide plate 15 and the second light guide plate 16.

  The light scattering unit 20 is configured to uniformly illuminate a display unit or an input unit (not shown) on the surface side of the light guide plate body 17 of each of the first light guide plate 15 and the second light guide plate 16. is there. In the embodiment of the present invention, as shown in FIG. 6, the light scattering portion 20 is composed of a plurality of convex bodies, for example, scattering dots, and is provided along the traveling direction of light from the LED 5, As the distance from the LED 5 increases, the density of scattered dots increases. However, a large number of minute protrusions or the like may be arranged instead of the scattering dots. As a method of forming the light scattering portion 20, a known method can be used. For example, a method of previously forming a convex body constituting the light scattering portion 20 on the surface of the light guide plate main body portion 17 or the light guide member 10. A method of printing a convex body in a subsequent process can be used.

  In the mobile phone 1 including the light guide member 10 according to the embodiment of the present invention, light of different colors from the plurality of LEDs 5a and 5b is applied to one end surfaces of the first light guide plate 15 and the second light guide plate 16, respectively. The first light receiving unit 18 and the second light receiving unit 19 that are provided receive the light and guide it to the inside thereof, thereby illuminating the display unit or the input unit to be illuminated. For this reason, even when a plurality of applications are incorporated in one electronic device, the display unit or the input unit can be easily determined for each application by changing the illumination color. At that time, the first light guide plate 15 and the second light guide plate 16 constituting the light guide member 10 are formed of a flexible resin material, so that the light guide member 10 can be easily deformed. ing. For this reason, it can be disposed in close contact with the back surface of the display unit or the input unit of the electronic device. Further, since the light scattering portion 20 is formed on the surface of the light guide plate main body portion 17 of each of the first light guide plate 15 and the second light guide plate 16, the light quantity of the LED 5 is insufficient, light reception leakage or attenuation due to the distance from the LED 5. The luminance can be increased by reinforcement, and thus the display unit or the input unit can be brightly illuminated.

  Next, an outline of a manufacturing process until the light guide member 10 and the LED 5 according to the present embodiment are arranged on the substrate 2 will be described.

  First, a film of polycarbonate resin (manufactured by Mitsubishi Plastics) having a thickness of 0.125 mm is prepared. Next, the polycarbonate film is placed in a concave mold of a molding die. Subsequently, the convex mold having the convex part and the concave mold are closed, and at a temperature of 110 ° C. for 40 seconds, the predetermined part on one side of the polycarbonate film is squeezed so that the height is 0.4 mm. Perform molding. Moreover, the 1st notch part 25 is formed using a punching die. As a result, the 2nd light guide plate 16 provided with the light guide plate main-body part 17, the 2nd light-receiving part 19 which has a desired shape, and the 1st notch part 25 is obtained.

  Next, after a similar polycarbonate film prepared separately is drawn, the second notch 26 is formed using a punching die. Accordingly, the first light guide plate 15 including the light guide plate main body portion 17, the first light receiving portion 18 having a desired shape, and the second notch portion 26 is obtained. Then, in the 1st light guide plate 15 and the 2nd light guide plate 16 shape | molded separately, white dot printing is given to the surface of each light guide plate main-body part 17, and the light-scattering part 20 is formed. Next, the light guide member 10 is obtained by combining the first light guide plate 15 and the second light guide plate 16. Finally, the light guide member 10 and the LEDs 5a and 5b are fixed on the substrate 2 so that the LEDs 5a and 5b are close to the light receiving portions of the light guide member 10, respectively. As a result, in the light guide member 10, the first light receiving unit 18 and the second light receiving unit 19 of the first light guide plate 15 and the second light guide plate 16 are respectively connected to the specific LEDs 5 a and LEDs 5 b arranged on the substrate 2. It becomes almost the same height as the light emitting part.

  The light guide member 10 according to the embodiment of the present invention and the mobile phone 1 equipped with the light guide member 10 have been described above. However, the light guide member according to the present invention and the electronic device equipped with the light guide member are described above. The present invention is not limited to this embodiment, and various modifications can be made.

  The shape, height, arrangement, or number of the first light receiving unit 18 and the second light receiving unit 19 are appropriately changed according to the thickness of the light guide plate used, the shape and height of the LED 5, or the function of the required electronic device. Is possible. For example, when a thin light guide plate is employed, a form in which the first light receiving portion of the first light guide plate is bent in the thickness direction of the light guide member 10 so as to be the height of the light emitting position of the LED 5 is formed. Also good.

  Further, two or more (for example, three) light guide plates are laminated to constitute the light guide member 10, and in addition to the LED 5a that emits red light and the LED 5b that emits blue light, the LED 5 that emits green light is a substrate. Or may be arranged.

  The present invention can be used in industries that manufacture or use illumination members used in electronic equipment.

1 ... Mobile phone (electronic equipment)
2 ... Substrate 5 ... LED (light source)
5a ... LED (light source)
5b ... LED (light source)
DESCRIPTION OF SYMBOLS 10 ... Light guide member 15 ... 1st light guide plate 16 ... 2nd light guide plate 17 ... Light guide plate main-body part 18 ... 1st light-receiving part 19 ... 2nd light-receiving part 20 ... Light-scattering part 21 ... Convex part 25 ... 1st notch Part (notch)
26 ... 2nd notch part (notch part)

Claims (5)

A light guide member that is disposed opposite to a display unit or input unit to be illuminated, receives light from a plurality of light sources, guides the light into the inside, and illuminates the display unit or input unit,
The light guide member is configured by laminating at least two light guide plates,
Each of the light guide plates includes a light receiving portion that receives light from the specific light source on an end surface of the light guide plate.
At least one of the light guide plates is bent in the thickness direction of the light guide member so that the light receiving portion of each light guide plate approaches the height of the light emission position of the specific light source ,
At least one light guide plate of the light guide plates has a notch cut out in a direction away from the light source that does not need to be guided to the light guide plate,
A light guide plate other than the at least one light guide plate has a convex portion bent so as to enter the notch portion in the thickness direction of the light guide member, and the light receiving portion requires a light guide. A light guide member that is close to the height of the light emitting position . The light guide member according to claim 1, wherein the convex portion has a shape that gradually inclines in the opposite direction from the opening of the cutout portion. The light guide member according to claim 1, wherein the light guide plate includes a plurality of light scattering portions inward of the light receiving portion along a traveling direction of light from the light source. The light scattering section has a plurality of convex bodies that polarize received light toward the display section or the input section, and the density of the plurality of convex bodies increases as the distance from the light source increases. The light guide member according to claim 3. An electronic apparatus comprising the light guide member according to any one of claims 1 to 4.

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