JP2013200490A - Illumination device and electronic apparatus - Google Patents

Abstract

A high-performance illumination device capable of realizing a ring-shaped light emitting region and an electronic apparatus having such an illumination device are provided.
One surface of a light guide plate has a flat light guide plate, and a plurality of light sources that are arranged so that a light emitting surface faces the side surface of the light guide plate and enters light into the light guide plate from the side surface The light guide plate is disposed so as to surround the central portion, and a prism is formed that reflects light emitted from a plurality of light sources and propagates through the light guide plate and exits from the other surface of the light guide plate. Each of the plurality of light sources is formed such that light emitted from the light source is emitted from the other surface in a region facing the light source across the central portion of the light guide plate.
[Selection] Figure 1

Description

  Various illumination devices are used in electronic devices for various purposes. For example, in a portable information terminal such as a cellular phone, an illumination device that generates various light emission patterns is used as an interface for notifying a user of an incoming call or e-mail. The illumination device is also considered as a part of the device design. In addition to an interface function for notifying incoming calls, the illumination device also exhibits a decorative effect by illuminating a part of the exterior.

JP 2002-208308 A JP 2003-057448 A JP 2003-262734 A JP 2003-308752 A International Publication No. 2007/020820 Pamphlet

  An illumination device mounted on an electronic device is required to have various shapes of light emitting regions according to the function and structure of the electronic device. In addition, from the viewpoint of improving the decorative effect and the like, it is desired to have a uniform light emission distribution without a dark portion and to have high light incident efficiency and high luminance.

  An object of the present invention is to provide a high-performance illumination device capable of realizing a ring-shaped light emitting region, and an electronic apparatus equipped with such an illumination device.

  According to an embodiment of the present invention, there is provided a flat light guide plate and a plurality of light sources that are arranged such that a light emitting surface faces the side surface of the light guide plate and that allows light to enter the light guide plate from the side surface. The light guide plate is disposed on one surface of the light guide plate so as to surround a central portion of the light guide plate, reflects light emitted from the plurality of light sources and propagates through the light guide plate, and reflects the other light of the light guide plate. A prism that emits from the surface is formed, and the prism opposes the light emitted from the light source to each of the plurality of light sources across the central portion of the light guide plate. An illumination device is provided which is shaped to emit from the other surface in the region.

  Further, according to another aspect of the embodiment, a plurality of light sources that are arranged so that a light emitting surface is opposed to a flat light guide plate and a side surface of the light guide plate, and light enters the light guide plate from the side surface The light guide plate is disposed on one surface of the light guide plate so as to surround a central portion of the light guide plate, and reflects light emitted from the plurality of light sources and propagating through the light guide plate. A prism that is emitted from the other surface of the light source, and the prism emits the light emitted from the light source to each of the plurality of light sources with the central portion of the light guide plate interposed therebetween. There is provided an electronic apparatus having an illumination device that is formed so as to emit light from the other surface in a region facing the light source, and a control device that controls the light source of the illumination device.

  According to the disclosed illumination device and electronic device, it is possible to realize a high-luminance illumination device having a ring-shaped light emitting region, high in-plane uniformity of light emission luminance, and an electronic device having such an illumination device. Can do.

1A and 1B are a plan view and a schematic sectional view showing the structure of an illumination apparatus according to the first embodiment. FIG. 2 is a schematic sectional view (No. 1) showing the structure of the groove of the prism formed in the light guide plate. FIG. 3 is a schematic cross-sectional view (part 2) showing the structure of the groove of the prism formed in the light guide plate. FIG. 4 is a schematic sectional view (No. 3) showing the structure of the groove of the prism formed in the light guide plate. FIG. 5 is a schematic sectional view (No. 4) showing the structure of the groove of the prism formed in the light guide plate. FIG. 6 is a diagram showing the effect of the illumination device according to the first embodiment. FIG. 7 is a graph (part 1) showing the alignment characteristics of a general LED. FIG. 8 is a graph (part 2) showing the orientation characteristics of a general LED. FIG. 9 is a graph (No. 3) showing the alignment characteristics of a general LED. FIG. 10 is a perspective view (No. 1) showing the structure of the lens sheet. FIG. 11 is a perspective view (No. 2) showing the structure of the lens sheet. FIG. 12 is a perspective view (No. 3) showing the structure of the lens sheet. FIG. 13 is a schematic diagram (part 1) illustrating the structure of an illumination apparatus according to a comparative example. FIG. 14 is a schematic diagram (part 2) illustrating the structure of an illumination device according to a comparative example. FIG. 15 is a schematic diagram (part 3) illustrating the structure of an illumination apparatus according to a comparative example. FIG. 16 is a plan view showing the structure of the illumination device according to the second embodiment. FIG. 17 is a plan view (part 1) showing the structure of the illumination device according to the third embodiment. FIG. 18 is a plan view (part 2) showing the structure of the illumination device according to the third embodiment. FIG. 19 is a plan view (part 3) illustrating the structure of the illumination device according to the third embodiment. FIG. 20 is a diagram (part 1) for explaining the influence of the shape of the inner surface of the opening of the light guide plate. FIG. 21 is a diagram (part 2) for explaining the influence of the shape of the inner surface of the opening of the light guide plate. FIG. 22 is a perspective view (No. 1) showing the structure of the electronic apparatus according to the fourth embodiment. FIG. 23 is a perspective view (No. 2) showing the structure of the electronic apparatus according to the fourth embodiment. FIG. 24 is a perspective view (No. 3) showing the structure of the electronic device according to the fourth embodiment. FIG. 25 is a diagram (part 1) illustrating the operation of the electronic device according to the fourth embodiment. FIG. 26 is a diagram (part 2) illustrating the operation of the electronic device according to the fourth embodiment. FIG. 27 is a schematic diagram (part 1) illustrating the structure of an electronic apparatus according to the fifth embodiment. FIG. 28 is a schematic diagram (part 2) illustrating the structure of the electronic apparatus according to the fifth embodiment. FIG. 29 is a schematic diagram (part 3) illustrating the structure of the electronic apparatus according to the fifth embodiment. FIG. 30 is a schematic diagram (part 4) illustrating the structure of the electronic device according to the fifth embodiment.

[First Embodiment]
The illumination device according to the first embodiment will be described with reference to FIGS.

  FIG. 1 is a plan view and a schematic sectional view showing the structure of the illumination apparatus according to the present embodiment. 2 to 5 are schematic sectional views showing the structure of the grooves of the prism formed on the light guide plate. FIG. 6 is a diagram illustrating the effect of the illumination device according to the present embodiment. 7 to 9 are graphs showing alignment characteristics of general LEDs. 10 to 12 are perspective views showing the structure of the lens sheet.

  First, the structure of the illumination device according to the present embodiment will be described with reference to FIGS. 1A is a plan view of the illumination apparatus according to the present embodiment, and FIG. 1B is a cross-sectional view taken along the line AA ′ of FIG.

  As shown in FIG. 1A and FIG. 1B, the illumination device 10 according to the present embodiment includes a flat light guide plate 20, a plurality of LEDs 30 arranged around the light guide plate 20, and the light guide plate 20. And a lens sheet 40 disposed on the top.

  The light guide plate 20 is a plate-like body made of a material that transmits visible light, such as an acrylic resin, and has two opposing surfaces and a side surface of the outer peripheral portion. The planar shape of the light guide plate 20 is circular, for example, as shown in FIG.

  A prism 24 is provided on the surface of the light guide plate 20 opposite to the side on which the lens sheet 40 is disposed. The prism 24 is formed by a plurality of circular grooves 26 provided concentrically on the surface of the light guide plate 20. The groove 26 is drawn with a dotted line in the drawing, but is not provided intermittently, but is a continuous groove that goes around.

  For example, as shown in FIG. 2, the groove 26 is located on the center side of the light guide plate 20 and has a slope 26 a having an inclination of θ1 with respect to the surface of the light guide plate 20, and is located on the outer peripheral side of the light guide plate 20. It is a V-shaped groove having an inclined surface 26b whose inclination with respect to the surface is θ2. The center of the light guide plate 20 is the center point of a concentric circle that describes the plurality of grooves 26 of the prism 24.

  The slope θ1 of the slope 26a is such that when light propagating in the light guide plate 20 is reflected by the slope 26a, the reflected light is incident on the surface of the light guide plate 20 at an angle larger than the total reflection critical angle. The light is emitted from the light guide plate 20 (see the light beam 28a in FIG. 2).

  On the other hand, the slope θ2 of the inclined surface 26b is such that when the light propagating in the light guide plate 20 is reflected by the inclined surface 26b, the reflected light is smaller than the total reflection critical angle with respect to the surface of the light guide plate 20. It is set so as to enter and return into the light guide plate 20 (see the light beam 28b in FIG. 2).

  The LEDs 30 are arranged at equal intervals along the side surface of the light guide plate 20 so that the normal direction of the light emitting surface faces the center point of a concentric circle that describes the plurality of grooves 26 of the prism 24. Thereby, the light emitted from the LED 30 is introduced into the light guide plate 20 from the side surface of the light guide plate 20.

  As shown in FIG. 1A, for example, six LEDs 30 are arranged at equal intervals on the side surface of the light guide plate 20. The normal directions of the light emitting surfaces of adjacent LEDs 30 form an angle of 60 degrees with each other. The arrangement interval of the LEDs 30 is desirably uniform from the viewpoint of improving the in-plane uniformity of the emission intensity. The number of LEDs 30 can be appropriately selected according to the size of the light guide plate 20 and the LEDs 30 so that the light emission intensity is uniform in the surface.

  The LED 30 is not particularly limited, and may be a single color LED or an RGB integrated LED. In the present embodiment, an LED is described as an example of a typical light source, but the light source to be used is not limited to the LED. For example, a small lamp, an organic electroluminescence (EL) element, or the like may be used instead of the LED.

  A control device (not shown) is connected to each LED 30. This control device turns on / off the LED 30 and controls the emission color when an RGB integrated LED is used. The light emission timing and light emission color of each LED 30 can be controlled by the control device. The plurality of LEDs 30 may be collectively controlled or individually controlled. In addition, the timing of light emission / extinguishment may be controlled such that the plurality of LEDs 30 are sequentially turned on / off.

  The light emitted from the LED 30 is introduced into the light guide plate 20 from the side surface of the light guide plate 20. In FIG. 3, when focusing on the light incident on the light guide plate 20 from the left LED 30, the slope 26 a of the groove 26 of the prism 24 located on the LED 30 side from the center of the light guide plate 20 is centered from the side surface of the light guide plate 20. It becomes a shade against the light going to. For this reason, the light traveling toward the center of the light guide plate 20 is incident on the slope 26b of the groove 26 of the prism 24, but is not incident on the slope 26a.

  Of the light incident on the slope 26b of the groove 26 of the prism 24, light satisfying the total reflection condition is reflected by the slope 26b. The slope [theta] 2 of the slope 26b is set so that the reflected light is incident on the surface of the light guide plate 20 at an angle smaller than the total reflection critical angle, and therefore is not emitted outside the light guide plate 20. . Thereby, the light introduced into the light guide plate 20 propagates through the light guide plate 20 while repeating total reflection on the opposing surface of the light guide plate 20.

  In the prism 24 located farther from the LED 30 than the central region of the light guide plate 20, the slope 26 a of the groove 26 is located on the LED 30 side. For this reason, when the light propagating in the light guide plate 20 exceeds the central region of the light guide plate 20, the light propagating in the light guide plate 20 can enter the inclined surface 26 a of the groove 26 of the prism 24.

  Of the light incident on the inclined surface 26a of the groove 26 of the prism 24 in the process of propagating through the light guide plate 20, light rays that satisfy the total reflection condition with respect to the inclined surface 26a are totally reflected by the inclined surface 26a. Of the light totally reflected by the inclined surface 26a of the groove 26, light incident on the surface of the light guide plate 20 at an angle larger than the total reflection critical angle is emitted from the surface side opposite to the prism 24 forming surface. The Of the light emitted from the surface side of the light guide plate 20, only the light incident on the human eye can be felt bright by the person and becomes effective light.

  On the other hand, a light ray that does not satisfy the total reflection condition with respect to the inclined surface 26a of the groove 26 (for example, the light ray 28b, represented by a dotted line in FIG. 2) is transmitted through the inclined surface 26a of the groove 26 to form the prism 24 of the light guide plate 20. It is emitted from the surface side and does not become effective light. In addition, even if the light is emitted from the surface opposite to the surface on which the prism 24 is formed, the person cannot perceive light that does not enter the human eye, so it is as effective as light that does not satisfy the total reflection condition. It will not be light.

  Even if light is emitted from the surface of the light guide plate 20, the position of the light guide plate where the light enters the human eye is bright, and the position of the light guide plate 20 where the light does not enter the human eye feels dark. From the viewpoint of more light out of the light propagating through the light guide plate 20 satisfying the total reflection condition, exiting from the surface of the light guide plate, and entering the human eye, the slope 26a of the groove 26 with respect to the surface of the light guide plate 20 It is desirable to set the inclination θ1 to an angle of 40 to 50 degrees. By setting the slope θ1 of the inclined surface 26a of the prism 24 to an angle of 40 to 50 degrees, light propagating in the light guide plate 20 within an angle range within ± 10 degrees with respect to the horizontal direction can be transmitted in the vertical direction of the light guide plate 20. Can be reflected at an angle within about ± 10 degrees and emitted outside the light guide plate 20.

  Since the prism 24 of the illumination device according to the present embodiment can adjust the emission angle from the light guide plate 20 by appropriately setting the slope θ1 of the slope 26a of the groove 26, it can direct light directly to the viewer. It is possible to have an efficient optical configuration.

  As the prism 24, for example, as shown in FIG. 4, a structure in which a plurality of grooves 26 are arranged so that the inclined surface 26b of the groove 26 and the inclined surface 26a of the adjacent groove 26 are in contact with each other can be considered.

  In the case of such a prism 24, the slope θ1 of the slope 26a of the groove 26 is set to 42 degrees, the slope θ2 of the slope 26b is set to 2 degrees, and the pitch P between the grooves 26 is set to 0.2 mm, for example. The depth D in this case is defined by the inclinations θ1 and θ2 and the pitch P, and is about 0.007 mm.

  For example, as shown in FIG. 5, a region parallel to the surface of the light guide plate 20 may be provided between the adjacent grooves 26.

  In the prism 24 of FIGS. 4 and 5, the same effect can be obtained by setting the slope θ1 to about 41 to 46 degrees and the slope θ2 to about 1 to 5 degrees.

  Since the light emitted from the LED 30 propagates while spreading in the lateral direction, the intensity of the light emitted from the LED 30 becomes brighter as it is closer to the LED 30 and becomes darker as it is farther away.

  In the prism shown in FIGS. 4 and 5, light inclined by about 1.5 degrees from the horizontal is reflected by the prism 24 and is emitted from the light guide plate 20 at a substantially vertical angle. By reducing the slope θ2 of the slope 26b, even if light inclined by about 1.5 degrees from the horizontal among the light from the LED 30 is reflected by the slope 26a of the first groove 26, the light at that angle disappears. Light at other angles is affected by the inclined surface 26b having the inclination θ2, and is generated one after another as it propagates. Therefore, by reducing the inclination θ2, the angle of light propagating in the light guide plate 20 is affected, and the distribution can be made uniform.

  In order to cancel out the in-plane distribution of brightness and achieve in-plane uniformity, the structure of the prism 24 may be changed as appropriate.

  For example, since the brightness is high near the LED 30, the pitch P can be set large, and the brightness decreases as the distance from the LED 30 decreases, so the pitch P can be reduced to compensate for this. If the pitch P is larger than 0.2 mm, the interval between the prisms 24 can be resolved when a person looks at the light emitting surface, and the reflection portion and the non-prism portion by the prism 24 appear to be a striped pattern. End up. From this point of view, the pitch P of the grooves 26 is preferably set to 0.2 mm or less.

  Instead of changing the pitch P of the grooves 26, the depth D of the grooves 26 may be changed. The deeper the groove 26, that is, the larger the area of the inclined surface 26a of the groove 26, the more light is reflected. Therefore, since the brightness is high near the LED 30, the depth D of the groove 26 is set shallow, and the brightness decreases as the distance from the LED 30 decreases. Therefore, the depth D of the groove 26 can be increased to compensate for this.

  As described above, in the illumination device according to the present embodiment, the light emitted from each LED 30 is emitted from the light guide plate 20 in a region facing the LED 30 with the central portion of the light guide plate 20 interposed therebetween. In addition, a prism 24 is formed. Moreover, the prism 24 is formed with respect to each of LED30 so that the light emitted from LED30 may be radiate | emitted from the light guide plate 20 in the area | region between LED30 and the center part of a light guide plate. This is to improve the in-plane uniformity of the emission intensity.

  As shown in FIG. 6, a dark portion 32 where light from these LEDs 30 is not directly incident exists in a region between the LEDs 30. In this case, when the light from the LED 30 is reflected by the prism 24 region closer to the LED 30 and is emitted from the light guide plate 20, the brightness is close to the LED 30 and the brightness is high, so the difference in brightness from the dark portion 32 increases. Light from an LED (not shown) disposed on the opposite side surface of the light guide plate 20 is incident on the dark portion 32, but this is insufficient to eliminate the difference in brightness between locations away from the light source.

  On the other hand, in the illumination device according to the present embodiment, light is not emitted from the light guide plate 20 in the prism 24 region on the side close to the LED 30, so that there is no difference in brightness from the dark portion 32. Thereby, the in-plane uniformity of emitted light intensity can be improved. Moreover, since the light from the LEDs 30 arranged on the opposite side surface spreads more and reaches the prism 24 region, the number of LEDs 30 arranged around the light guide plate 20 can be reduced. As a result, the number of parts can be reduced, and cost and power consumption can be reduced.

  7 and 8 are graphs showing alignment characteristics of general LEDs. FIG. 7 is a polar coordinate graph showing the relationship between the angle and emission intensity in air, and FIG. 8 is a two-dimensional graph showing the relationship between the emission intensity and angle in air and in the light guide plate. In these graphs, the angle represents an angle inclined from the normal direction of the light emitting surface of the LED. The emission intensity represents a value normalized by the emission intensity in the normal direction.

  When light emitted from the LED 30 enters the light guide plate 20 from the air, the orientation characteristics change due to the influence of the difference in refractive index. For example, as shown in FIG. 8, when the refractive index of the constituent material of the light guide plate 20 is 1.49 (acrylic resin), the angle when the emission intensity is 0.5 is about 54 degrees in the air. On the other hand, it is about 32 degrees in the light guide plate.

  Here, the light guide plate 20 having a thickness of 0.5 mm has a 4 mm wide ring shape in which grooves 26 having an inclination θ1 of the inclined surface 26a of 42 degrees and an inclination θ2 of the inclined surface 26b of 2 degrees are arranged at a pitch of 0.2 mm. Assume that the prism 24 is provided.

  The number of times the light incident on the light guide plate 20 is reflected by the inclined surface 26b of the prism 24 when passing through the front prism 24 region is 1 to 4 times depending on the angle when entering the light guide plate 20. As shown in FIG. 7, light having an incident angle of about 17 degrees or less is reflected once while passing through the prism 24. Light having an incident angle of about 17 degrees to about 28 degrees is reflected twice while passing through the prism 24. Light having an incident angle of about 28 degrees to about 38 degrees is reflected three times while passing through the prism 24. Light having an incident angle of 38 degrees or more is reflected four times when passing through the prism 24.

  On the other hand, when the light is reflected by the inclined surface 26b of the prism 24, the angle formed with respect to the surface of the light guide plate 20 gradually increases due to modulation by the inclination θ2 of the inclined surface 26b. As a result, light having an incident angle of about 36 degrees or more exceeds the total reflection critical angle by three reflections by the inclined surface 26b, and is emitted from the light guide plate 20.

  However, as shown in FIG. 8, the ratio of the light emitted from the light guide plate 20 is about 6% of the total light, and the remaining 94% of the light propagates to the rear prism 24 region. can do.

  The lens sheet 40 is not particularly limited, but it is desirable that the lens sheet 40 diverges after once condensing light. By providing the lens sheet 40 that condenses the light once condensed, the visible range of the light emitted from the light guide plate 20 can be expanded, and the entire light emitting region can be recognized by human eyes.

  As such a lens sheet, a lens array sheet in which a plurality of lens structures are periodically arranged can be applied. For example, as shown in FIG. 10, a microlens array sheet in which spherical microlenses 42a are arranged in a lattice shape can be applied. Alternatively, for example, as shown in FIG. 11, a lens sheet obtained by bonding two lenticular lens sheets in which a plurality of cylindrical lenses 42b are arranged in parallel so that the cylindrical lenses 42b intersect each other may be applied. it can.

  Alternatively, a light diffusion sheet may be applied as the lens sheet 40. As the light diffusing sheet, for example, as shown in FIG. 12, a material in which a diffusing material 42c for diffusing light is put in the material, a material having irregularities on the surface, an opaque member such as milky white, etc. can be applied. it can. Strictly speaking, the light diffusing sheet does not exhibit a lens effect, but it is handled and traded as the same kind of material as the lens sheet in the market. In this specification, the term “lens sheet” includes a light diffusion sheet.

  Note that the lens sheet 40 is arranged to increase visibility, and is not necessarily arranged when sufficient visibility can be obtained without the lens sheet 40.

  In the illumination device according to the present embodiment, light incident from the side surface of the light guide plate 20 is emitted from the surface of the light guide plate 20. This is because the optical path length of the light emitted from the LED 30 is lengthened to increase the spread.

  As another illumination device, for example, a structure as shown in FIGS. 13 and 14 can be considered. 13 (a) and 14 (a) are cross-sectional views showing the cross-sectional structure of the illumination device, and FIGS. 13 (b) and 14 (b) are views of an electronic component equipped with the illumination device as viewed from the outside. It is a top view which shows the light emission state.

  The illumination device of FIG. 13 is one in which the light emitting surface of the LED 30 is arranged in contact with the inside of the exterior component 50 of the electronic device. The light emitted from the LED 30 is emitted after propagating through the exterior component 50. In the case of this illumination device, the light emitted from the LED 30 spreads in the lateral direction in the process of propagating through the exterior component 50. However, as the exterior component 50 becomes thinner as the electronic equipment becomes smaller and thinner, the lateral spread cannot be sufficiently obtained. As a result, when viewed from the surface side of the exterior component, for example, as shown in FIG.

  The illuminating device of FIG. 14 is an example in which the RGB integrated LED 30 is used in the same structure as the illuminating device of FIG. When an RGB integrated LED is used as the LED 30, for example, as shown in FIGS. 14A and 14B, the light of each color is emitted from the exterior component 50 before being sufficiently mixed. . As a result, a desired color expression becomes difficult.

  On the other hand, in the illumination device according to the present embodiment, the light emitted from the LED 30 propagates in a direction parallel to the surface of the light guide plate 20, and then the light reflected by the prism 24 is perpendicular to the surface of the light guide plate 20. Emits in the direction. For this reason, compared with the illumination apparatus of FIG.13 and FIG.14, the distance until the light emitted from LED30 is radiate | emitted from the light-guide plate 20 becomes long.

  Therefore, the light emitted from the LED 30 can be sufficiently spread before being emitted from the light guide plate 20, and uneven distribution of light emission intensity can be prevented. Further, in the case where the RGB integrated LED 30 is used, the light of each color can be sufficiently mixed before being emitted from the light guide plate 20, and a desired color expression can be achieved.

  Further, as another illumination device, for example, a structure as shown in FIG. 15 is conceivable. In the illumination device of FIG. 15, an opening 22 is provided in a ring-shaped light guide plate 20, and an LED 30 is disposed on the inner surface of the opening 22. In this illumination device, since the LEDs 30 are arranged in the openings 22 of the light guide plate 20, the arrangement of the LEDs 30 becomes more difficult as the ring-shaped light emitting area is reduced in size. The general RGB integrated LED 30 has a size of about 4 mm, and the inner diameter of the ring cannot be made smaller than this.

  On the other hand, in the illumination device according to the present embodiment, since the LEDs 30 are arranged around the light guide plate 20, the size and arrangement of the LEDs 30 do not affect the downsizing of the ring.

  Thus, according to the present embodiment, it is possible to realize a ring-shaped illumination device that has high in-plane uniformity of light emission luminance and little color unevenness.

[Second Embodiment]
An illumination device according to the second embodiment will be described with reference to FIG. Constituent elements similar to those of the illumination apparatus according to the first embodiment shown in FIGS. 1 to 12 are denoted by the same reference numerals, and description thereof is omitted or simplified.

  FIG. 16 is a plan view showing the structure of the illumination device according to the present embodiment.

  In the illumination device according to the first embodiment, the prism 24 is formed by the plurality of concentric grooves 26 provided on the surface of the light guide plate 20 as described above.

  On the other hand, in the illumination device 10 according to the present embodiment, as shown in FIG. 16, the prism 24 is formed by one groove 26 drawn in a spiral shape. The method of setting parameters such as the pitch P and depth D of the grooves 26, the slope θ1 of the slope 26a, and the slope θ2 of the slope 26b is the same as in the first embodiment. In addition, the other configuration of the illumination device excluding the groove 26 is the same as that of the illumination device according to the first embodiment.

  In the manufacture of the light guide plate 20 having the prism 24, the groove 26 is formed by cutting the light guide plate 20 using a cutting tool such as a cutting tool. When a cutting tool is inserted into the plane of the light guide plate 20, burrs are generated at the first insertion portion, and this portion becomes a singular point, and light noise is generated. As the number of the grooves 26 increases, the portion into which the cutting tool is inserted increases, and burrs are generated by that number, and noise increases.

  Therefore, in the illumination device 10 according to the present embodiment, instead of forming the plurality of grooves 26, one groove 26 is formed in a spiral shape so that a one-stroke-like cutting process can be performed, and the cutting tool insertion point is determined. One place. As a result, it is possible to greatly reduce the portion where burrs are generated and minimize the noise. Thereby, the in-plane uniformity of the light emission luminance can be further improved, and the occurrence of uneven color can be further suppressed.

  Thus, according to the present embodiment, it is possible to realize a ring-shaped illumination device that has high in-plane uniformity of light emission luminance and little color unevenness.

[Third Embodiment]
An illumination apparatus according to the third embodiment will be described with reference to FIGS. Constituent elements similar to those of the illumination device according to the first and second embodiments shown in FIGS. 1 to 16 are denoted by the same reference numerals, and description thereof is omitted or simplified.

  17 to 19 are plan views showing the structure of the illumination device according to the present embodiment. 20 and 21 are diagrams for explaining the influence of the shape of the side surface of the light guide plate.

  In the illumination device according to the first and second embodiments, as described above, the planar shape of the light guide plate 20 is circular.

  On the other hand, in the illumination device 10 according to the present embodiment, as shown in FIGS. 17 to 19, the planar shape of the light guide 20 is a polygonal shape, and the light emitting surface of the LED 30 and the inner side surface of the light guide plate 20 are parallel. It is arranged to be. FIG. 17 is an example in which the outer shape of the light guide plate 20 is a rectangle, and the LEDs 30 are arranged on each side of the rectangle. FIG. 18 shows an example in which the outer shape of the light guide plate 20 is a pentagon, and the LEDs 30 are arranged on each side of the pentagon. FIG. 19 shows an example in which the outer shape of the light guide plate 20 is a hexagon, and the LEDs 30 are arranged on each side of the hexagon.

  Even when there are as few as four LEDs 30, for example, there is a distance from the LED 30 to the prism 24, so that light can be sufficiently spread and a gentle distribution can be obtained. For example, when there are as many as 30 LEDs 30, it is possible that light emitted from adjacent LEDs 30 may be mixed, but gradation is applied due to the mixed color, and a gentle color change can be realized. The number of LEDs 30 can be appropriately selected according to the structure and design requirements of the electronic device to which the illumination device is applied.

  The light guide plate 20 may be formed by a polygon having a number of corners corresponding to the number of LEDs 30 or may be formed by a polygon having a larger number of strokes than the number of LEDs 30. For example, the LEDs 30 may be arranged on only four of the eight sides of the octagonal light guide plate 20. Further, the outer shape of the light guide plate 20 is not necessarily a regular polygon.

  When the side surface of the light guide plate 20 is a curved line such as an arc, the distance between the LED 30 and the light guide plate 20 at the center portion and the end portion of the LED 30 as shown in FIGS. 20 (b) and 20 (c). Is different. In the central part where the distance between the LED 30 and the light guide plate 20 is short, there is little leakage of the diverging light, and there is much incident light, whereas in the end part where the distance between the LED 30 and the light guiding plate 20 is far, the diverging light There are many leaks and less incident light. As a result, it causes illumination and uneven brightness of illumination light. Also, for the strongest light that is in the normal direction of the LED 30, the light from the center part enters the light guide plate 20 perpendicularly, but the incident angle of the light from the end part changes by the curvature of the arc, Incidence efficiency is reduced by the amount of reflection loss (see FIG. 20A).

  On the other hand, the outer shape of the light guide plate 20 is a polygonal shape, and the light emitting surface of the LED 30 and the side surface of the light guide plate 20 are made parallel, so that the distance between the LED 30 and the light guide plate 20 is as shown in FIG. As shown in FIG. 21 (c), the central portion and the end portion are the same. Further, the incident angle of light to the light guide plate 20 is also the same at the center and at the end as shown in FIG. Thereby, the light leakage loss by the place and the variation in the light incident efficiency can be reduced, and the cause of the uneven brightness can be eliminated.

  In addition, by aligning the light emitting surface of the LED 30 and the inner surface of the light guide plate 20, the positioning between the light guide plate 20 and the LED 30 when the LED 30 is disposed is compared with the case where the opening 22 is arcuate. There is also an effect that it is possible to easily.

  Thus, according to the present embodiment, according to the present embodiment, it is possible to realize a ring-shaped illumination device that has high in-plane uniformity of light emission luminance and little color unevenness.

[Fourth Embodiment]
An electronic apparatus according to the fourth embodiment will be described with reference to FIGS. Constituent elements similar to those of the illumination device according to the first to third embodiments shown in FIGS. 1 to 21 are denoted by the same reference numerals, and description thereof is omitted or simplified.

  22 to 24 are perspective views showing the structure of the electronic apparatus according to the present embodiment. 25 and 26 are flowcharts for explaining the operation of the electronic apparatus according to the present embodiment.

  In the present embodiment, a mobile phone to which the illumination device according to the first to third embodiments is applied is shown as an example of an electronic device to which the illumination device according to the first to third embodiments is applied.

  A cellular phone 80 shown in FIG. 22 includes a first casing 82 and a second casing 84, and the first casing 82 and the second casing 84 are formed to be foldable. FIG. 22 shows a state in which the mobile phone 80 is opened, and FIGS. 23 and 24 show a state in which the mobile phone 80 is closed.

  As shown in FIG. 22, the first casing 82 is provided with an operation unit 86 having an input device including a character input key, a numeric keypad, a cross key, a determination key, and other function keys. The second housing 84 is provided with a display unit 88 for displaying predetermined information. As shown in FIG. 23 or FIG. 24, a light emitting unit 90 is provided on the back surface of the second housing 84. The light emitting unit 90 is not particularly limited, and is for visually informing an incoming call or e-mail, for example. The light emitting unit 90 may be disposed on the operation unit 86 or the display unit 88.

  A cellular phone 80 shown in FIGS. 23 and 24 is an example in which the illumination device 10 according to any one of the first to third embodiments is applied as the light emitting unit 90.

  For example, in the illumination device 10 according to the first embodiment shown in FIG. 1, various lighting patterns can be displayed on the light emitting unit 90 as shown in FIG. 23 by arbitrarily combining the emission colors of the six LEDs 30. . Moreover, the lighting pattern of the light emission part 90 can also be dynamically changed by arbitrarily combining the light emission timings of the six LEDs 30. In addition, as shown in FIG. 24, an accessory can be arranged in the light emitting unit 90 and the illumination device 10 can illuminate the accessory.

  The light emitting unit 90 of the mobile phone 80 can be used as, for example, an interface for notifying incoming calls and emails and alerts. Also, if the personal information registered in the address book and the lighting pattern are associated in advance, in addition to the function for notifying incoming calls and emails, it is possible to visually inform the originator of the phone and the sender of the email. Can also be used.

  Such a function can be realized by using, for example, a control device that performs processing as shown in FIGS.

  FIG. 25 is an example of the control device 60 for visually informing the call originator and the e-mail sender.

  First, the receiver 62 receives information such as a phone call and an e-mail.

  Next, the sender determination unit 64 compares the received information with the information registered in the address book to determine the originator of the telephone and the sender of the e-mail.

  Next, the lighting pattern information associated with the determined transmission source / transmission source is obtained from the database 66, and the LED control device 68 is driven based on the obtained lighting pattern information.

  As a result, the plurality of LEDs 30 of the illumination device 10 can be turned on in a predetermined lighting pattern, and the user of the mobile phone 80 can be notified visually of the incoming call and the incoming call destination.

  FIG. 26 is an example of a control device 60 for visually informing an alert.

  First, predetermined alert information is stored in the alert information storage unit 70 by the user of the mobile phone 80 or the like. As the alert information, for example, there is alert information for notifying the user of a predetermined time.

  Next, the alert necessity determination unit 72 compares the current time with the alert information stored in the alert information storage unit 70 to determine whether or not an alert needs to be generated.

  When the current time matches the alert information stored in the alert information storage unit 70, the lighting pattern information is obtained from the database 66, and the LED control device 68 is driven based on the obtained lighting pattern information.

  Thereby, the plurality of LEDs 30 of the illumination device 10 can be turned on in a predetermined lighting pattern, and an alert can be visually notified to the user of the mobile phone 80.

  By using the illumination device of the first to fourth embodiments for the light emitting unit 90 of the mobile phone 80, various lighting patterns that emit light in a ring shape can be realized. In addition, since the illumination devices of the first to third embodiments have high in-plane uniformity of light emission luminance and little color unevenness, it is possible to obtain a visually beautiful lighting pattern.

  In addition, the illumination devices according to the first to fourth embodiments are configured such that light emitted from the LEDs 30 is incident from the side surface of the light guide plate 20 and is emitted to the front surface side of the light guide plate 20, and the thickness of the illumination device can be reduced. There are also benefits. Accordingly, it is possible to reduce the size and thickness of an electronic device equipped with an illumination device.

  As described above, according to the present embodiment, various lighting patterns with uniform light emission luminance and little color unevenness can be displayed on the exterior portion of the electronic device, and the role and design as an interface can be improved. it can. In addition, it is possible to reduce the size and thickness of an electronic device equipped with an illumination device.

[Fifth Embodiment]
An electronic apparatus according to the fifth embodiment will be described with reference to FIGS. The same components as those of the illumination device according to the first to third embodiments shown in FIGS. 1 to 21 and the electronic device according to the fourth embodiment shown in FIGS. 22 to 26 are denoted by the same reference numerals, and description thereof is omitted. Keep it concise.

  FIG. 27 to FIG. 30 are schematic views showing how the illumination device is mounted on an electronic device.

  In the present embodiment, a mounting form when the illumination device of the first to third embodiments is mounted on an electronic device will be described.

  The method of mounting the illumination device of the first to third embodiments on an electronic device is not particularly limited, but various modes as shown in FIGS. 25 to 28, for example, are conceivable.

  In the method shown in FIG. 27, the component 50 of the electronic device and the light guide plate 20 are integrally formed. The exterior part of the part which forms the light-guide plate 20 is thickened, and LED30 is arrange | positioned in a level | step difference part. By integrally forming the exterior component 50 and the light guide plate 20, there is no positional deviation between the exterior component 50 and the light guide plate 20, and there is an effect that the number of components can be reduced. The LED 30 may be fixed to the exterior component 50 in which the light guide plate 20 is integrally formed, or may be formed on a circuit board disposed to face the exterior component 50. Such a mounting method is applicable, for example, as an exterior part of the second casing 84 of the mobile phone 80 shown in FIG.

  The second housing 84 shown in FIG. 23 uses the exterior component 50 shown in FIG. 27 and can have a structure as shown in FIG. 28, for example.

  A liquid crystal display device 94 and a predetermined mounting component 96 are mounted on one surface (the lower side in the drawing) of the circuit board 92. A predetermined mounting component 96 and the LED 30 are mounted on the other surface (upper side in the drawing) of the circuit board 92. The mounting component 96 includes, for example, components that form the control device 60. The circuit board 92 is contained in a second housing 84 formed by an exterior component 50 and an exterior component 98 that are integrally formed with the light guide plate 20. If the space between the exterior component 50 and the exterior component 98 is sealed with an adhesive 100 such as a tape, a housing that also serves as a water-stop cover can be formed. The LEDs 30 formed on the circuit board 92 are arranged so as to be positioned in the opening 22 of the light guide plate 20, and the illumination device 10 is formed by a combination of the circuit board 92 and the exterior component 50.

  When the exterior component 50 and the light guide plate 20 are integrally formed, a diffusion material may be mixed in the material so that the exterior component 50 has the same effect as the lens sheet (diffusion sheet).

  When the exterior component 50 and the light guide plate 20 are integrally formed, a diffusion material may be mixed in the material so that the exterior component 50 has the same effect as the lens sheet (diffusion sheet). In this case, for example, as shown in FIG. 29 (a), a diffusion material may be mixed in the entire exterior part. For example, as shown in FIG. 29 (b), the light guide plate 20 portion is transparent by two-color molding. It is good also as a material and the part used as an original case is good also as a material containing a diffusing material.

  The method shown in FIG. 30 is an example in which an exterior cover 52 is provided so as to cover the exterior component 50 shown in FIG. If the accessory 54 is fitted on the illumination device 10 of the exterior cover 52, the accessory 54 can be illuminated by the illumination device 10. At this time, a recess 56 may be formed on the surface of the exterior component 50 to suppress interference of the accessory 54. Such a mounting method can be applied as an exterior component of the second housing 84 of the mobile phone 80 shown in FIG. 24, for example.

[Modified Embodiment]
The present invention is not limited to the above embodiment, and various modifications are possible.

  For example, in the first to third embodiments, the illumination device using the ring-shaped band region as the light-emitting region has been described. However, the entire ring-shaped band region does not necessarily have to be the light-emitting region. In the illumination device according to the above-described embodiment, since the portion where the prism 24 is provided is a light emitting region, only a specific region of the ring-shaped belt region is selectively selected by appropriately selecting a region where the prism 24 is formed. It can also emit light.

  For example, only a region having a predetermined angle in the ring-shaped band region can emit light, or a pattern of a plurality of rings forming concentric circles can be emitted. In the case where light is emitted only in a predetermined angle region, the number of LEDs 30 may be reduced.

  In the first to third embodiments, the illumination device having the ring-shaped light emitting region is shown. However, the inner diameter of the ring-shaped prism 24 may be reduced to form a circular light emitting region.

  In the first embodiment, the prism 24 having the plurality of circular grooves 26 is used. In the second and third embodiments, the prism 24 having the spiral grooves 26 is used. However, the grooves 26 forming the prism 24 are used. Is not necessarily formed so as to draw a perfect circle. For example, a groove formed to draw an ellipse ring or spiral may be used.

  In the fourth and fifth embodiments, the illumination device according to the first to third embodiments is applied to a mobile phone. However, the present invention is widely applicable not only to mobile phones but also to various electronic devices that require an illumination device. Can be applied.

  Further, the structures and constituent materials of the illumination device and the electronic device described in the above embodiment are merely examples, and can be appropriately modified or changed according to technical common sense of those skilled in the art.

  Regarding the above embodiment, the following additional notes are disclosed.

(Appendix 1) A flat light guide plate;
A plurality of light sources that are arranged such that a light emitting surface faces the side surface of the light guide plate, and incident light into the light guide plate from the side surface;
The light guide plate is disposed on one surface of the light guide plate so as to surround a central portion of the light guide plate, reflects light emitted from the plurality of light sources and propagates through the light guide plate, and is reflected from the other surface of the light guide plate. An outgoing prism is formed,
The prism emits the light emitted from the light source to each of the plurality of light sources from the other surface in a region facing the light source across the central portion of the light guide plate. An illumination device characterized by being formed.

(Supplementary note 2) In the illumination device according to supplementary note 1,
The prism does not emit the light emitted from the light source to each of the plurality of light sources from the other surface in a region between the light source and the central portion of the light guide plate. An illumination device characterized by being formed.

(Supplementary note 3) In the illumination device according to supplementary note 1 or 2,
The prism includes a plurality of ring-shaped grooves arranged concentrically.

(Appendix 4) In the illumination device according to Appendix 1 or 2,
The prism has a spiral groove. An illumination device, wherein:

(Appendix 5) In the illumination device according to Appendix 3 or 4,
The groove is formed by a V-shaped groove having a first slope located on the side surface side of the light guide plate and a second slope located on the center portion side of the light guide plate. Illumination device characterized.

(Supplementary note 6) In the illumination device according to supplementary note 5,
The angle formed between the one surface of the light guide plate and the first inclined surface is 1 to 5 degrees, and the angle formed between the one surface of the light guide plate and the second inclined surface is 41 degrees to 46. It is an illumination device characterized by the degree.

(Appendix 7) In the illumination device according to any one of appendices 3 to 6,
The illumination device is characterized in that the pitch between the grooves becomes narrower as the distance from the light source increases.

(Appendix 8) In the illumination device according to any one of appendices 3 to 7,
The illumination device is characterized in that the depth of the groove increases as the distance from the light source increases.

(Appendix 9) In the illumination device according to any one of appendices 3 to 8,
The pitch between the said grooves is 0.2 mm or less. The illumination apparatus characterized by the above-mentioned.

(Appendix 10) In the illumination device according to any one of appendices 1 to 9,
The light guide plate has a polygonal shape with a number of corners corresponding to the number of the plurality of light sources.

(Appendix 11) In the illumination device according to any one of appendices 1 to 10,
The illumination device, wherein the side surface of the light guide facing the light emitting surface of the light source is flat.

(Supplementary note 12) In the illumination device according to any one of supplementary notes 1 to 11,
An illumination device further comprising a lens sheet disposed on the other surface side of the light guide plate.

(Supplementary note 13) In the illumination device according to supplementary note 12,
The illumination device according to claim 1, wherein the lens sheet is a lens array sheet in which a plurality of spherical lenses are arranged in a lattice shape.

(Supplementary note 14) In the illumination device according to supplementary note 12,
The illumination device according to claim 1, wherein the lens sheet is obtained by bonding two lenticular lens sheets in which a plurality of cylindrical lenses are arranged in parallel so that the cylindrical lenses intersect each other.

(Supplementary note 15) In the illumination device according to supplementary note 12,
The illumination device, wherein the lens sheet is a light diffusion sheet including a diffusion material that diffuses light.

(Supplementary Note 16) The light guide plate includes a flat light guide plate, and a plurality of light sources that are arranged so that a light emitting surface faces the side surface of the light guide plate and allows light to enter the light guide plate from the side surface. A prism that is disposed on one surface of the light guide plate so as to surround a central portion of the light guide plate, reflects light emitted from the plurality of light sources and propagates through the light guide plate, and is emitted from the other surface of the light guide plate The prism is configured such that, for each of the plurality of light sources, the light emitted from the light source is transmitted to the other light source in a region facing the light source across the central portion of the light guide plate. An illumination device formed to emit from the surface;
An electronic apparatus comprising: a control device that controls the light source of the illumination device.

(Supplementary Note 17) In the electronic device according to Supplementary Note 16,
The plurality of light sources are formed on a circuit board on which the control device is formed,
The electronic device, wherein the light guide plate is disposed on the circuit board on which the plurality of light sources are formed.

(Supplementary note 18) In the electronic device according to supplementary note 16 or 17,
The said light guide plate is integrally formed with exterior components. The electronic device characterized by the above-mentioned.

(Supplementary note 19) In the electronic device according to supplementary note 18,
The exterior component includes a diffusing material that diffuses light.

DESCRIPTION OF SYMBOLS 10 ... Illumination apparatus 20 ... Light guide plate 22 ... Opening part 24 ... Prism 26 ... Grooves 26a, 26b ... Slope 28 ... Light beam 30 ... LED
40 ... Lens sheet 42a ... Micro lens 42b ... Cylindrical lens 42c ... Diffusion material 50, 98 ... Exterior component 52 ... Exterior cover 54 ... Accessory 56 ... Recess 60 ... Control device 62 ... Receiver 64 ... Transmission source determination unit 66 ... Database 68 ... LED control device 70 ... alert information storage unit 72 ... alert necessity determination unit 80 ... mobile phone 82 ... first housing 84 ... second housing 86 ... operation unit 88 ... display unit 90 ... light emitting unit 92 ... circuit board 94 ... Liquid crystal display device 96 ... Mounting component 100 ... Adhesive material

  The present invention relates to an illumination device and an electronic apparatus including the illumination device.

  Various illumination devices are used in electronic devices for various purposes. For example, in a portable information terminal such as a cellular phone, an illumination device that generates various light emission patterns is used as an interface for notifying a user of an incoming call or e-mail. The illumination device is also considered as a part of the device design. In addition to an interface function for notifying incoming calls, the illumination device also exhibits a decorative effect by illuminating a part of the exterior.

JP 2002-208308 A JP 2003-057448 A JP 2003-262734 A JP 2003-308752 A International Publication No. 2007/020820 Pamphlet

  An illumination device mounted on an electronic device is required to have various shapes of light emitting regions according to the function and structure of the electronic device. In addition, from the viewpoint of improving the decorative effect and the like, it is desired to have a uniform light emission distribution without a dark portion and to have high light incident efficiency and high luminance.

  An object of the present invention is to provide a high-performance illumination device capable of realizing a ring-shaped light emitting region, and an electronic apparatus equipped with such an illumination device.

  According to an embodiment of the present invention, there is provided a flat light guide plate and a plurality of light sources that are arranged such that a light emitting surface faces the side surface of the light guide plate and that allows light to enter the light guide plate from the side surface. The light guide plate is disposed on one surface of the light guide plate so as to surround a central portion of the light guide plate, reflects light emitted from the plurality of light sources and propagates through the light guide plate, and reflects the other light of the light guide plate. A prism that emits from the surface is formed, and the prism opposes the light emitted from the light source to each of the plurality of light sources across the central portion of the light guide plate. An illumination device is provided which is shaped to emit from the other surface in the region.

  Further, according to another aspect of the embodiment, a plurality of light sources that are arranged so that a light emitting surface is opposed to a flat light guide plate and a side surface of the light guide plate, and light enters the light guide plate from the side surface The light guide plate is disposed on one surface of the light guide plate so as to surround a central portion of the light guide plate, and reflects light emitted from the plurality of light sources and propagating through the light guide plate. A prism that is emitted from the other surface of the light source, and the prism emits the light emitted from the light source to each of the plurality of light sources with the central portion of the light guide plate interposed therebetween. There is provided an electronic apparatus having an illumination device that is formed so as to emit light from the other surface in a region facing the light source, and a control device that controls the light source of the illumination device.

  According to the disclosed illumination device and electronic device, it is possible to realize a high-luminance illumination device having a ring-shaped light emitting region, high in-plane uniformity of light emission luminance, and an electronic device having such an illumination device. Can do.

1A and 1B are a plan view and a schematic sectional view showing the structure of an illumination apparatus according to the first embodiment. FIG. 2 is a schematic sectional view (No. 1) showing the structure of the groove of the prism formed in the light guide plate. FIG. 3 is a schematic cross-sectional view (part 2) showing the structure of the groove of the prism formed in the light guide plate. FIG. 4 is a schematic sectional view (No. 3) showing the structure of the groove of the prism formed in the light guide plate. FIG. 5 is a schematic sectional view (No. 4) showing the structure of the groove of the prism formed in the light guide plate. FIG. 6 is a diagram showing the effect of the illumination device according to the first embodiment. FIG. 7 is a graph (part 1) showing the alignment characteristics of a general LED. FIG. 8 is a graph (part 2) showing the orientation characteristics of a general LED. FIG. 9 is a graph (No. 3) showing the alignment characteristics of a general LED. FIG. 10 is a perspective view (No. 1) showing the structure of the lens sheet. FIG. 11 is a perspective view (No. 2) showing the structure of the lens sheet. FIG. 12 is a perspective view (No. 3) showing the structure of the lens sheet. FIG. 13 is a schematic diagram (part 1) illustrating the structure of an illumination apparatus according to a comparative example. FIG. 14 is a schematic diagram (part 2) illustrating the structure of an illumination device according to a comparative example. FIG. 15 is a schematic diagram (part 3) illustrating the structure of an illumination apparatus according to a comparative example. FIG. 16 is a plan view showing the structure of the illumination device according to the second embodiment. FIG. 17 is a plan view (part 1) showing the structure of the illumination device according to the third embodiment. FIG. 18 is a plan view (part 2) showing the structure of the illumination device according to the third embodiment. FIG. 19 is a plan view (part 3) illustrating the structure of the illumination device according to the third embodiment. FIG. 20 is a diagram (part 1) for explaining the influence of the shape of the inner surface of the opening of the light guide plate. FIG. 21 is a diagram (part 2) for explaining the influence of the shape of the inner surface of the opening of the light guide plate. FIG. 22 is a perspective view (No. 1) showing the structure of the electronic apparatus according to the fourth embodiment. FIG. 23 is a perspective view (No. 2) showing the structure of the electronic apparatus according to the fourth embodiment. FIG. 24 is a perspective view (No. 3) showing the structure of the electronic device according to the fourth embodiment. FIG. 25 is a diagram (part 1) illustrating the operation of the electronic device according to the fourth embodiment. FIG. 26 is a diagram (part 2) illustrating the operation of the electronic device according to the fourth embodiment. FIG. 27 is a schematic diagram (part 1) illustrating the structure of an electronic apparatus according to the fifth embodiment. FIG. 28 is a schematic diagram (part 2) illustrating the structure of the electronic apparatus according to the fifth embodiment. FIG. 29 is a schematic diagram (part 3) illustrating the structure of the electronic apparatus according to the fifth embodiment. FIG. 30 is a schematic diagram (part 4) illustrating the structure of the electronic device according to the fifth embodiment.

[First Embodiment]
The illumination device according to the first embodiment will be described with reference to FIGS.

  FIG. 1 is a plan view and a schematic sectional view showing the structure of the illumination apparatus according to the present embodiment. 2 to 5 are schematic sectional views showing the structure of the grooves of the prism formed on the light guide plate. FIG. 6 is a diagram illustrating the effect of the illumination device according to the present embodiment. 7 to 9 are graphs showing alignment characteristics of general LEDs. 10 to 12 are perspective views showing the structure of the lens sheet.

  First, the structure of the illumination device according to the present embodiment will be described with reference to FIGS. 1A is a plan view of the illumination apparatus according to the present embodiment, and FIG. 1B is a cross-sectional view taken along the line AA ′ of FIG.

  As shown in FIG. 1A and FIG. 1B, the illumination device 10 according to the present embodiment includes a flat light guide plate 20, a plurality of LEDs 30 arranged around the light guide plate 20, and the light guide plate 20. And a lens sheet 40 disposed on the top.

  The light guide plate 20 is a plate-like body made of a material that transmits visible light, such as an acrylic resin, and has two opposing surfaces and a side surface of the outer peripheral portion. The planar shape of the light guide plate 20 is circular, for example, as shown in FIG.

  A prism 24 is provided on the surface of the light guide plate 20 opposite to the side on which the lens sheet 40 is disposed. The prism 24 is formed by a plurality of circular grooves 26 provided concentrically on the surface of the light guide plate 20. The groove 26 is drawn with a dotted line in the drawing, but is not provided intermittently, but is a continuous groove that goes around.

  For example, as shown in FIG. 2, the groove 26 is located on the center side of the light guide plate 20 and has a slope 26 a having an inclination of θ1 with respect to the surface of the light guide plate 20, and is located on the outer peripheral side of the light guide plate 20. It is a V-shaped groove having an inclined surface 26b whose inclination with respect to the surface is θ2. The center of the light guide plate 20 is the center point of a concentric circle that describes the plurality of grooves 26 of the prism 24.

  The slope θ1 of the slope 26a is such that when light propagating in the light guide plate 20 is reflected by the slope 26a, the reflected light is incident on the surface of the light guide plate 20 at an angle larger than the total reflection critical angle. The light is emitted from the light guide plate 20 (see the light beam 28a in FIG. 2).

  On the other hand, the slope θ2 of the inclined surface 26b is such that when the light propagating in the light guide plate 20 is reflected by the inclined surface 26b, the reflected light is smaller than the total reflection critical angle with respect to the surface of the light guide plate 20. It is set so as to enter and return into the light guide plate 20 (see the light beam 28b in FIG. 2).

  The LEDs 30 are arranged at equal intervals along the side surface of the light guide plate 20 so that the normal direction of the light emitting surface faces the center point of a concentric circle that describes the plurality of grooves 26 of the prism 24. Thereby, the light emitted from the LED 30 is introduced into the light guide plate 20 from the side surface of the light guide plate 20.

  As shown in FIG. 1A, for example, six LEDs 30 are arranged at equal intervals on the side surface of the light guide plate 20. The normal directions of the light emitting surfaces of adjacent LEDs 30 form an angle of 60 degrees with each other. The arrangement interval of the LEDs 30 is desirably uniform from the viewpoint of improving the in-plane uniformity of the emission intensity. The number of LEDs 30 can be appropriately selected according to the size of the light guide plate 20 and the LEDs 30 so that the light emission intensity is uniform in the surface.

  The LED 30 is not particularly limited, and may be a single color LED or an RGB integrated LED. In the present embodiment, an LED is described as an example of a typical light source, but the light source to be used is not limited to the LED. For example, a small lamp, an organic electroluminescence (EL) element, or the like may be used instead of the LED.

  A control device (not shown) is connected to each LED 30. This control device turns on / off the LED 30 and controls the emission color when an RGB integrated LED is used. The light emission timing and light emission color of each LED 30 can be controlled by the control device. The plurality of LEDs 30 may be collectively controlled or individually controlled. In addition, the timing of light emission / extinguishment may be controlled such that the plurality of LEDs 30 are sequentially turned on / off.

  The light emitted from the LED 30 is introduced into the light guide plate 20 from the side surface of the light guide plate 20. In FIG. 3, when focusing on the light incident on the light guide plate 20 from the left LED 30, the slope 26 a of the groove 26 of the prism 24 located on the LED 30 side from the center of the light guide plate 20 is centered from the side surface of the light guide plate 20. It becomes a shade against the light going to. For this reason, the light traveling toward the center of the light guide plate 20 is incident on the slope 26b of the groove 26 of the prism 24, but is not incident on the slope 26a.

  Of the light incident on the slope 26b of the groove 26 of the prism 24, light satisfying the total reflection condition is reflected by the slope 26b. The slope [theta] 2 of the slope 26b is set so that the reflected light is incident on the surface of the light guide plate 20 at an angle smaller than the total reflection critical angle, and therefore is not emitted outside the light guide plate 20. . Thereby, the light introduced into the light guide plate 20 propagates through the light guide plate 20 while repeating total reflection on the opposing surface of the light guide plate 20.

  In the prism 24 located farther from the LED 30 than the central region of the light guide plate 20, the slope 26 a of the groove 26 is located on the LED 30 side. For this reason, when the light propagating in the light guide plate 20 exceeds the central region of the light guide plate 20, the light propagating in the light guide plate 20 can enter the inclined surface 26 a of the groove 26 of the prism 24.

  Of the light incident on the inclined surface 26a of the groove 26 of the prism 24 in the process of propagating through the light guide plate 20, light rays that satisfy the total reflection condition with respect to the inclined surface 26a are totally reflected by the inclined surface 26a. Of the light totally reflected by the inclined surface 26a of the groove 26, light incident on the surface of the light guide plate 20 at an angle larger than the total reflection critical angle is emitted from the surface side opposite to the prism 24 forming surface. The Of the light emitted from the surface side of the light guide plate 20, only the light incident on the human eye can be felt bright by the person and becomes effective light.

  On the other hand, a light ray that does not satisfy the total reflection condition with respect to the inclined surface 26a of the groove 26 (for example, the light ray 28b, represented by a dotted line in FIG. 2) is transmitted through the inclined surface 26a of the groove 26 to form the prism 24 of the light guide plate 20. It is emitted from the surface side and does not become effective light. In addition, even if the light is emitted from the surface opposite to the surface on which the prism 24 is formed, the person cannot perceive light that does not enter the human eye, so it is as effective as light that does not satisfy the total reflection condition. It will not be light.

  Even if light is emitted from the surface of the light guide plate 20, the position of the light guide plate where the light enters the human eye is bright, and the position of the light guide plate 20 where the light does not enter the human eye feels dark. From the viewpoint of more light out of the light propagating through the light guide plate 20 satisfying the total reflection condition, exiting from the surface of the light guide plate, and entering the human eye, the slope 26a of the groove 26 with respect to the surface of the light guide plate 20 It is desirable to set the inclination θ1 to an angle of 40 to 50 degrees. By setting the slope θ1 of the inclined surface 26a of the prism 24 to an angle of 40 to 50 degrees, light propagating in the light guide plate 20 within an angle range within ± 10 degrees with respect to the horizontal direction can be transmitted in the vertical direction of the light guide plate 20. Can be reflected at an angle within about ± 10 degrees and emitted outside the light guide plate 20.

  Since the prism 24 of the illumination device according to the present embodiment can adjust the emission angle from the light guide plate 20 by appropriately setting the slope θ1 of the slope 26a of the groove 26, it can direct light directly to the viewer. It is possible to have an efficient optical configuration.

  As the prism 24, for example, as shown in FIG. 4, a structure in which a plurality of grooves 26 are arranged so that the inclined surface 26b of the groove 26 and the inclined surface 26a of the adjacent groove 26 are in contact with each other can be considered.

  In the case of such a prism 24, the slope θ1 of the slope 26a of the groove 26 is set to 42 degrees, the slope θ2 of the slope 26b is set to 2 degrees, and the pitch P between the grooves 26 is set to 0.2 mm, for example. The depth D in this case is defined by the inclinations θ1 and θ2 and the pitch P, and is about 0.007 mm.

  For example, as shown in FIG. 5, a region parallel to the surface of the light guide plate 20 may be provided between the adjacent grooves 26.

  In the prism 24 of FIGS. 4 and 5, the same effect can be obtained by setting the slope θ1 to about 41 to 46 degrees and the slope θ2 to about 1 to 5 degrees.

  Since the light emitted from the LED 30 propagates while spreading in the lateral direction, the intensity of the light emitted from the LED 30 becomes brighter as it is closer to the LED 30 and becomes darker as it is farther away.

  In the prism shown in FIGS. 4 and 5, light inclined by about 1.5 degrees from the horizontal is reflected by the prism 24 and is emitted from the light guide plate 20 at a substantially vertical angle. By reducing the slope θ2 of the slope 26b, even if light inclined by about 1.5 degrees from the horizontal among the light from the LED 30 is reflected by the slope 26a of the first groove 26, the light at that angle disappears. Light at other angles is affected by the inclined surface 26b having the inclination θ2, and is generated one after another as it propagates. Therefore, by reducing the inclination θ2, the angle of light propagating in the light guide plate 20 is affected, and the distribution can be made uniform.

  In order to cancel out the in-plane distribution of brightness and achieve in-plane uniformity, the structure of the prism 24 may be changed as appropriate.

  For example, since the brightness is high near the LED 30, the pitch P can be set large, and the brightness decreases as the distance from the LED 30 decreases, so the pitch P can be reduced to compensate for this. If the pitch P is larger than 0.2 mm, the interval between the prisms 24 can be resolved when a person looks at the light emitting surface, and the reflection portion and the non-prism portion by the prism 24 appear to be a striped pattern. End up. From this point of view, the pitch P of the grooves 26 is preferably set to 0.2 mm or less.

  Instead of changing the pitch P of the grooves 26, the depth D of the grooves 26 may be changed. The deeper the groove 26, that is, the larger the area of the inclined surface 26a of the groove 26, the more light is reflected. Therefore, since the brightness is high near the LED 30, the depth D of the groove 26 is set shallow, and the brightness decreases as the distance from the LED 30 decreases. Therefore, the depth D of the groove 26 can be increased to compensate for this.

  As described above, in the illumination device according to the present embodiment, the light emitted from each LED 30 is emitted from the light guide plate 20 in a region facing the LED 30 with the central portion of the light guide plate 20 interposed therebetween. In addition, a prism 24 is formed. Moreover, the prism 24 is formed with respect to each of LED30 so that the light emitted from LED30 may be radiate | emitted from the light guide plate 20 in the area | region between LED30 and the center part of a light guide plate. This is to improve the in-plane uniformity of the emission intensity.

  As shown in FIG. 6, a dark portion 32 where light from these LEDs 30 is not directly incident exists in a region between the LEDs 30. In this case, when the light from the LED 30 is reflected by the prism 24 region closer to the LED 30 and is emitted from the light guide plate 20, the brightness is close to the LED 30 and the brightness is high, so the difference in brightness from the dark portion 32 increases. Light from an LED (not shown) disposed on the opposite side surface of the light guide plate 20 is incident on the dark portion 32, but this is insufficient to eliminate the difference in brightness between locations away from the light source.

  On the other hand, in the illumination device according to the present embodiment, light is not emitted from the light guide plate 20 in the prism 24 region on the side close to the LED 30, so that there is no difference in brightness from the dark portion 32. Thereby, the in-plane uniformity of emitted light intensity can be improved. Moreover, since the light from the LEDs 30 arranged on the opposite side surface spreads more and reaches the prism 24 region, the number of LEDs 30 arranged around the light guide plate 20 can be reduced. As a result, the number of parts can be reduced, and cost and power consumption can be reduced.

  7 and 8 are graphs showing alignment characteristics of general LEDs. FIG. 7 is a polar coordinate graph showing the relationship between the angle and emission intensity in air, and FIG. 8 is a two-dimensional graph showing the relationship between the emission intensity and angle in air and in the light guide plate. In these graphs, the angle represents an angle inclined from the normal direction of the light emitting surface of the LED. The emission intensity represents a value normalized by the emission intensity in the normal direction.

  When light emitted from the LED 30 enters the light guide plate 20 from the air, the orientation characteristics change due to the influence of the difference in refractive index. For example, as shown in FIG. 8, when the refractive index of the constituent material of the light guide plate 20 is 1.49 (acrylic resin), the angle when the emission intensity is 0.5 is about 54 degrees in the air. On the other hand, it is about 32 degrees in the light guide plate.

  Here, the light guide plate 20 having a thickness of 0.5 mm has a 4 mm wide ring shape in which grooves 26 having an inclination θ1 of the inclined surface 26a of 42 degrees and an inclination θ2 of the inclined surface 26b of 2 degrees are arranged at a pitch of 0.2 mm. Assume that the prism 24 is provided.

  The number of times the light incident on the light guide plate 20 is reflected by the inclined surface 26b of the prism 24 when passing through the front prism 24 region is 1 to 4 times depending on the angle when entering the light guide plate 20. As shown in FIG. 7, light having an incident angle of about 17 degrees or less is reflected once while passing through the prism 24. Light having an incident angle of about 17 degrees to about 28 degrees is reflected twice while passing through the prism 24. Light having an incident angle of about 28 degrees to about 38 degrees is reflected three times while passing through the prism 24. Light having an incident angle of 38 degrees or more is reflected four times when passing through the prism 24.

  On the other hand, when the light is reflected by the inclined surface 26b of the prism 24, the angle formed with respect to the surface of the light guide plate 20 gradually increases due to modulation by the inclination θ2 of the inclined surface 26b. As a result, light having an incident angle of about 36 degrees or more exceeds the total reflection critical angle by three reflections by the inclined surface 26b, and is emitted from the light guide plate 20.

  However, as shown in FIG. 8, the ratio of the light emitted from the light guide plate 20 is about 6% of the total light, and the remaining 94% of the light propagates to the rear prism 24 region. can do.

  The lens sheet 40 is not particularly limited, but it is desirable that the lens sheet 40 diverges after once condensing light. By providing the lens sheet 40 that condenses the light once condensed, the visible range of the light emitted from the light guide plate 20 can be expanded, and the entire light emitting region can be recognized by human eyes.

  As such a lens sheet, a lens array sheet in which a plurality of lens structures are periodically arranged can be applied. For example, as shown in FIG. 10, a microlens array sheet in which spherical microlenses 42a are arranged in a lattice shape can be applied. Alternatively, for example, as shown in FIG. 11, a lens sheet obtained by bonding two lenticular lens sheets in which a plurality of cylindrical lenses 42b are arranged in parallel so that the cylindrical lenses 42b intersect each other may be applied. it can.

  Alternatively, a light diffusion sheet may be applied as the lens sheet 40. As the light diffusing sheet, for example, as shown in FIG. 12, a material in which a diffusing material 42c for diffusing light is put in the material, a material having irregularities on the surface, an opaque member such as milky white, etc. can be applied. it can. Strictly speaking, the light diffusing sheet does not exhibit a lens effect, but it is handled and traded as the same kind of material as the lens sheet in the market. In this specification, the term “lens sheet” includes a light diffusion sheet.

  Note that the lens sheet 40 is arranged to increase visibility, and is not necessarily arranged when sufficient visibility can be obtained without the lens sheet 40.

  In the illumination device according to the present embodiment, light incident from the side surface of the light guide plate 20 is emitted from the surface of the light guide plate 20. This is because the optical path length of the light emitted from the LED 30 is lengthened to increase the spread.

  As another illumination device, for example, a structure as shown in FIGS. 13 and 14 can be considered. 13 (a) and 14 (a) are cross-sectional views showing the cross-sectional structure of the illumination device, and FIGS. 13 (b) and 14 (b) are views of an electronic component equipped with the illumination device as viewed from the outside. It is a top view which shows the light emission state.

  The illumination device of FIG. 13 is one in which the light emitting surface of the LED 30 is arranged in contact with the inside of the exterior component 50 of the electronic device. The light emitted from the LED 30 is emitted after propagating through the exterior component 50. In the case of this illumination device, the light emitted from the LED 30 spreads in the lateral direction in the process of propagating through the exterior component 50. However, as the exterior component 50 becomes thinner as the electronic equipment becomes smaller and thinner, the lateral spread cannot be sufficiently obtained. As a result, when viewed from the surface side of the exterior component, for example, as shown in FIG.

  The illuminating device of FIG. 14 is an example in which the RGB integrated LED 30 is used in the same structure as the illuminating device of FIG. When an RGB integrated LED is used as the LED 30, for example, as shown in FIGS. 14A and 14B, the light of each color is emitted from the exterior component 50 before being sufficiently mixed. . As a result, a desired color expression becomes difficult.

  On the other hand, in the illumination device according to the present embodiment, the light emitted from the LED 30 propagates in a direction parallel to the surface of the light guide plate 20, and then the light reflected by the prism 24 is perpendicular to the surface of the light guide plate 20. Emits in the direction. For this reason, compared with the illumination apparatus of FIG.13 and FIG.14, the distance until the light emitted from LED30 is radiate | emitted from the light-guide plate 20 becomes long.

  Therefore, the light emitted from the LED 30 can be sufficiently spread before being emitted from the light guide plate 20, and uneven distribution of light emission intensity can be prevented. Further, in the case where the RGB integrated LED 30 is used, the light of each color can be sufficiently mixed before being emitted from the light guide plate 20, and a desired color expression can be achieved.

  Further, as another illumination device, for example, a structure as shown in FIG. 15 is conceivable. In the illumination device of FIG. 15, an opening 22 is provided in a ring-shaped light guide plate 20, and an LED 30 is disposed on the inner surface of the opening 22. In this illumination device, since the LEDs 30 are arranged in the openings 22 of the light guide plate 20, the arrangement of the LEDs 30 becomes more difficult as the ring-shaped light emitting area is reduced in size. The general RGB integrated LED 30 has a size of about 4 mm, and the inner diameter of the ring cannot be made smaller than this.

  On the other hand, in the illumination device according to the present embodiment, since the LEDs 30 are arranged around the light guide plate 20, the size and arrangement of the LEDs 30 do not affect the downsizing of the ring.

  Thus, according to the present embodiment, it is possible to realize a ring-shaped illumination device that has high in-plane uniformity of light emission luminance and little color unevenness.

[Second Embodiment]
An illumination device according to the second embodiment will be described with reference to FIG. Constituent elements similar to those of the illumination apparatus according to the first embodiment shown in FIGS. 1 to 12 are denoted by the same reference numerals, and description thereof is omitted or simplified.

  FIG. 16 is a plan view showing the structure of the illumination device according to the present embodiment.

  In the illumination device according to the first embodiment, the prism 24 is formed by the plurality of concentric grooves 26 provided on the surface of the light guide plate 20 as described above.

  On the other hand, in the illumination device 10 according to the present embodiment, as shown in FIG. 16, the prism 24 is formed by one groove 26 drawn in a spiral shape. The method of setting parameters such as the pitch P and depth D of the grooves 26, the slope θ1 of the slope 26a, and the slope θ2 of the slope 26b is the same as in the first embodiment. In addition, the other configuration of the illumination device excluding the groove 26 is the same as that of the illumination device according to the first embodiment.

  In the manufacture of the light guide plate 20 having the prism 24, the groove 26 is formed by cutting the light guide plate 20 using a cutting tool such as a cutting tool. When a cutting tool is inserted into the plane of the light guide plate 20, burrs are generated at the first insertion portion, and this portion becomes a singular point, and light noise is generated. As the number of the grooves 26 increases, the portion into which the cutting tool is inserted increases, and burrs are generated by that number, and noise increases.

  Therefore, in the illumination device 10 according to the present embodiment, instead of forming the plurality of grooves 26, one groove 26 is formed in a spiral shape so that a one-stroke-like cutting process can be performed, and the cutting tool insertion point is determined. One place. As a result, it is possible to greatly reduce the portion where burrs are generated and minimize the noise. Thereby, the in-plane uniformity of the light emission luminance can be further improved, and the occurrence of uneven color can be further suppressed.

  Thus, according to the present embodiment, it is possible to realize a ring-shaped illumination device that has high in-plane uniformity of light emission luminance and little color unevenness.

[Third Embodiment]
An illumination apparatus according to the third embodiment will be described with reference to FIGS. Constituent elements similar to those of the illumination device according to the first and second embodiments shown in FIGS.

  17 to 19 are plan views showing the structure of the illumination device according to the present embodiment. 20 and 21 are diagrams for explaining the influence of the shape of the side surface of the light guide plate.

  In the illumination device according to the first and second embodiments, as described above, the planar shape of the light guide plate 20 is circular.

  On the other hand, in the illumination device 10 according to the present embodiment, as shown in FIGS. 17 to 19, the planar shape of the light guide 20 is a polygonal shape, and the light emitting surface of the LED 30 and the inner side surface of the light guide plate 20 are parallel. It is arranged to be. FIG. 17 is an example in which the outer shape of the light guide plate 20 is a rectangle, and the LEDs 30 are arranged on each side of the rectangle. FIG. 18 shows an example in which the outer shape of the light guide plate 20 is a pentagon, and the LEDs 30 are arranged on each side of the pentagon. FIG. 19 shows an example in which the outer shape of the light guide plate 20 is a hexagon, and the LEDs 30 are arranged on each side of the hexagon.

  Even when there are as few as four LEDs 30, for example, there is a distance from the LED 30 to the prism 24, so that light can be sufficiently spread and a gentle distribution can be obtained. For example, when there are as many as 30 LEDs 30, it is possible that light emitted from adjacent LEDs 30 may be mixed, but gradation is applied due to the mixed color, and a gentle color change can be realized. The number of LEDs 30 can be appropriately selected according to the structure and design requirements of the electronic device to which the illumination device is applied.

  The light guide plate 20 may be formed by a polygon having a number of corners corresponding to the number of LEDs 30 or may be formed by a polygon having a larger number of strokes than the number of LEDs 30. For example, the LEDs 30 may be arranged on only four of the eight sides of the octagonal light guide plate 20. Further, the outer shape of the light guide plate 20 is not necessarily a regular polygon.

  When the side surface of the light guide plate 20 is a curved line such as an arc, the distance between the LED 30 and the light guide plate 20 at the center portion and the end portion of the LED 30 as shown in FIGS. 20 (b) and 20 (c). Is different. In the central part where the distance between the LED 30 and the light guide plate 20 is short, there is little leakage of the diverging light, and there is much incident light, whereas in the end part where the distance between the LED 30 and the light guiding plate 20 is far, the diverging light There are many leaks and less incident light. As a result, it causes illumination and uneven brightness of illumination light. Also, for the strongest light that is in the normal direction of the LED 30, the light from the center part enters the light guide plate 20 perpendicularly, but the incident angle of the light from the end part changes by the curvature of the arc, Incidence efficiency is reduced by the amount of reflection loss (see FIG. 20A).

  On the other hand, the outer shape of the light guide plate 20 is a polygonal shape, and the light emitting surface of the LED 30 and the side surface of the light guide plate 20 are made parallel, so that the distance between the LED 30 and the light guide plate 20 is as shown in FIG. As shown in FIG. 21 (c), the central portion and the end portion are the same. Further, the incident angle of light to the light guide plate 20 is also the same at the center and at the end as shown in FIG. Thereby, the light leakage loss by the place and the variation in the light incident efficiency can be reduced, and the cause of the uneven brightness can be eliminated.

  In addition, by aligning the light emitting surface of the LED 30 and the inner surface of the light guide plate 20, the positioning between the light guide plate 20 and the LED 30 when the LED 30 is disposed is compared with the case where the opening 22 is arcuate. There is also an effect that it is possible to easily.

  Thus, according to the present embodiment, according to the present embodiment, it is possible to realize a ring-shaped illumination device that has high in-plane uniformity of light emission luminance and little color unevenness.

[Fourth Embodiment]
An electronic apparatus according to the fourth embodiment will be described with reference to FIGS. Constituent elements similar to those of the illumination device according to the first to third embodiments shown in FIGS. 1 to 21 are denoted by the same reference numerals, and description thereof is omitted or simplified.

  22 to 24 are perspective views showing the structure of the electronic apparatus according to the present embodiment. 25 and 26 are flowcharts for explaining the operation of the electronic apparatus according to the present embodiment.

  In the present embodiment, a mobile phone to which the illumination device according to the first to third embodiments is applied is shown as an example of an electronic device to which the illumination device according to the first to third embodiments is applied.

  A cellular phone 80 shown in FIG. 22 includes a first casing 82 and a second casing 84, and the first casing 82 and the second casing 84 are formed to be foldable. FIG. 22 shows a state in which the mobile phone 80 is opened, and FIGS. 23 and 24 show a state in which the mobile phone 80 is closed.

  As shown in FIG. 22, the first casing 82 is provided with an operation unit 86 having an input device including a character input key, a numeric keypad, a cross key, a determination key, and other function keys. The second housing 84 is provided with a display unit 88 for displaying predetermined information. As shown in FIG. 23 or FIG. 24, a light emitting unit 90 is provided on the back surface of the second housing 84. The light emitting unit 90 is not particularly limited, and is for visually informing an incoming call or e-mail, for example. The light emitting unit 90 may be disposed on the operation unit 86 or the display unit 88.

  A cellular phone 80 shown in FIGS. 23 and 24 is an example in which the illumination device 10 according to any one of the first to third embodiments is applied as the light emitting unit 90.

  For example, in the illumination device 10 according to the first embodiment shown in FIG. 1, various lighting patterns can be displayed on the light emitting unit 90 as shown in FIG. 23 by arbitrarily combining the emission colors of the six LEDs 30. . Moreover, the lighting pattern of the light emission part 90 can also be dynamically changed by arbitrarily combining the light emission timings of the six LEDs 30. In addition, as shown in FIG. 24, an accessory can be arranged in the light emitting unit 90 and the illumination device 10 can illuminate the accessory.

  The light emitting unit 90 of the mobile phone 80 can be used as, for example, an interface for notifying incoming calls and emails and alerts. Also, if the personal information registered in the address book and the lighting pattern are associated in advance, in addition to the function for notifying incoming calls and emails, it is possible to visually inform the originator of the phone and the sender of the email. Can also be used.

  Such a function can be realized by using, for example, a control device that performs processing as shown in FIGS.

  FIG. 25 is an example of the control device 60 for visually informing the call originator and the e-mail sender.

  First, the receiver 62 receives information such as a phone call and an e-mail.

  Next, the sender determination unit 64 compares the received information with the information registered in the address book to determine the originator of the telephone and the sender of the e-mail.

  Next, the lighting pattern information associated with the determined transmission source / transmission source is obtained from the database 66, and the LED control device 68 is driven based on the obtained lighting pattern information.

  As a result, the plurality of LEDs 30 of the illumination device 10 can be turned on in a predetermined lighting pattern, and the user of the mobile phone 80 can be notified visually of the incoming call and the incoming call destination.

  FIG. 26 is an example of a control device 60 for visually informing an alert.

  First, predetermined alert information is stored in the alert information storage unit 70 by the user of the mobile phone 80 or the like. As the alert information, for example, there is alert information for notifying the user of a predetermined time.

  Next, the alert necessity determination unit 72 compares the current time with the alert information stored in the alert information storage unit 70 to determine whether or not an alert needs to be generated.

  When the current time matches the alert information stored in the alert information storage unit 70, the lighting pattern information is obtained from the database 66, and the LED control device 68 is driven based on the obtained lighting pattern information.

  Thereby, the plurality of LEDs 30 of the illumination device 10 can be turned on in a predetermined lighting pattern, and an alert can be visually notified to the user of the mobile phone 80.

  By using the illumination device of the first to fourth embodiments for the light emitting unit 90 of the mobile phone 80, various lighting patterns that emit light in a ring shape can be realized. In addition, since the illumination devices of the first to third embodiments have high in-plane uniformity of light emission luminance and little color unevenness, it is possible to obtain a visually beautiful lighting pattern.

  In addition, the illumination devices according to the first to fourth embodiments are configured such that light emitted from the LEDs 30 is incident from the side surface of the light guide plate 20 and is emitted to the front surface side of the light guide plate 20, and the thickness of the illumination device can be reduced. There are also benefits. Accordingly, it is possible to reduce the size and thickness of an electronic device equipped with an illumination device.

  As described above, according to the present embodiment, various lighting patterns with uniform light emission luminance and little color unevenness can be displayed on the exterior portion of the electronic device, and the role and design as an interface can be improved. it can. In addition, it is possible to reduce the size and thickness of an electronic device equipped with an illumination device.

[Fifth Embodiment]
An electronic apparatus according to the fifth embodiment will be described with reference to FIGS. The same components as those of the illumination device according to the first to third embodiments shown in FIGS. 1 to 21 and the electronic device according to the fourth embodiment shown in FIGS. 22 to 26 are denoted by the same reference numerals, and description thereof is omitted. Keep it concise.

  FIG. 27 to FIG. 30 are schematic views showing how the illumination device is mounted on an electronic device.

  In the present embodiment, a mounting form when the illumination device of the first to third embodiments is mounted on an electronic device will be described.

  The method of mounting the illumination device of the first to third embodiments on an electronic device is not particularly limited, but various modes as shown in FIGS. 25 to 28, for example, are conceivable.

  In the method shown in FIG. 27, the component 50 of the electronic device and the light guide plate 20 are integrally formed. The exterior part of the part which forms the light-guide plate 20 is thickened, and LED30 is arrange | positioned in a level | step difference part. By integrally forming the exterior component 50 and the light guide plate 20, there is no positional deviation between the exterior component 50 and the light guide plate 20, and there is an effect that the number of components can be reduced. The LED 30 may be fixed to the exterior component 50 in which the light guide plate 20 is integrally formed, or may be formed on a circuit board disposed to face the exterior component 50. Such a mounting method is applicable, for example, as an exterior part of the second casing 84 of the mobile phone 80 shown in FIG.

  The second housing 84 shown in FIG. 23 uses the exterior component 50 shown in FIG. 27 and can have a structure as shown in FIG. 28, for example.

  A liquid crystal display device 94 and a predetermined mounting component 96 are mounted on one surface (the lower side in the drawing) of the circuit board 92. A predetermined mounting component 96 and the LED 30 are mounted on the other surface (upper side in the drawing) of the circuit board 92. The mounting component 96 includes, for example, components that form the control device 60. The circuit board 92 is contained in a second housing 84 formed by an exterior component 50 and an exterior component 98 that are integrally formed with the light guide plate 20. If the space between the exterior component 50 and the exterior component 98 is sealed with an adhesive 100 such as a tape, a housing that also serves as a water-stop cover can be formed. The LEDs 30 formed on the circuit board 92 are arranged so as to be positioned in the opening 22 of the light guide plate 20, and the illumination device 10 is formed by a combination of the circuit board 92 and the exterior component 50.

  When the exterior component 50 and the light guide plate 20 are integrally formed, a diffusion material may be mixed in the material so that the exterior component 50 has the same effect as the lens sheet (diffusion sheet).

  When the exterior component 50 and the light guide plate 20 are integrally formed, a diffusion material may be mixed in the material so that the exterior component 50 has the same effect as the lens sheet (diffusion sheet). In this case, for example, as shown in FIG. 29 (a), a diffusion material may be mixed in the entire exterior part. For example, as shown in FIG. 29 (b), the light guide plate 20 portion is transparent by two-color molding. It is good also as a material and the part used as an original case is good also as a material containing a diffusing material.

  The method shown in FIG. 30 is an example in which an exterior cover 52 is provided so as to cover the exterior component 50 shown in FIG. If the accessory 54 is fitted on the illumination device 10 of the exterior cover 52, the accessory 54 can be illuminated by the illumination device 10. At this time, a recess 56 may be formed on the surface of the exterior component 50 to suppress interference of the accessory 54. Such a mounting method can be applied as an exterior component of the second housing 84 of the mobile phone 80 shown in FIG. 24, for example.

[Modified Embodiment]
The present invention is not limited to the above embodiment, and various modifications are possible.

  For example, in the first to third embodiments, the illumination device using the ring-shaped band region as the light-emitting region has been described. However, the entire ring-shaped band region does not necessarily have to be the light-emitting region. In the illumination device according to the above-described embodiment, since the portion where the prism 24 is provided is a light emitting region, only a specific region of the ring-shaped belt region is selectively selected by appropriately selecting a region where the prism 24 is formed. It can also emit light.

  For example, only a region having a predetermined angle in the ring-shaped band region can emit light, or a pattern of a plurality of rings forming concentric circles can be emitted. In the case where light is emitted only in a predetermined angle region, the number of LEDs 30 may be reduced.

  In the first to third embodiments, the illumination device having the ring-shaped light emitting region is shown. However, the inner diameter of the ring-shaped prism 24 may be reduced to form a circular light emitting region.

  In the first embodiment, the prism 24 having the plurality of circular grooves 26 is used. In the second and third embodiments, the prism 24 having the spiral grooves 26 is used. However, the grooves 26 forming the prism 24 are used. Is not necessarily formed so as to draw a perfect circle. For example, a groove formed to draw an ellipse ring or spiral may be used.

  In the fourth and fifth embodiments, the illumination device according to the first to third embodiments is applied to a mobile phone. However, the present invention is widely applicable not only to mobile phones but also to various electronic devices that require an illumination device. Can be applied.

  Further, the structures and constituent materials of the illumination device and the electronic device described in the above embodiment are merely examples, and can be appropriately modified or changed according to technical common sense of those skilled in the art.

  Regarding the above embodiment, the following additional notes are disclosed.

(Appendix 1) A flat light guide plate;
A plurality of light sources that are arranged such that a light emitting surface faces the side surface of the light guide plate, and incident light into the light guide plate from the side surface;
The light guide plate is disposed on one surface of the light guide plate so as to surround a central portion of the light guide plate, reflects light emitted from the plurality of light sources and propagates through the light guide plate, and is reflected from the other surface of the light guide plate. An outgoing prism is formed,
The prism emits the light emitted from the light source to each of the plurality of light sources from the other surface in a region facing the light source across the central portion of the light guide plate. An illumination device characterized by being formed.

(Supplementary note 2) In the illumination device according to supplementary note 1,
The prism does not emit the light emitted from the light source to each of the plurality of light sources from the other surface in a region between the light source and the central portion of the light guide plate. An illumination device characterized by being formed.

(Supplementary note 3) In the illumination device according to supplementary note 1 or 2,
The prism includes a plurality of ring-shaped grooves arranged concentrically.

(Appendix 4) In the illumination device according to Appendix 1 or 2,
The prism has a spiral groove. An illumination device, wherein:

(Appendix 5) In the illumination device according to Appendix 3 or 4,
The groove is formed by a V-shaped groove having a first slope located on the side surface side of the light guide plate and a second slope located on the center portion side of the light guide plate. Illumination device characterized.

(Supplementary note 6) In the illumination device according to supplementary note 5,
The angle formed between the one surface of the light guide plate and the first inclined surface is 1 to 5 degrees, and the angle formed between the one surface of the light guide plate and the second inclined surface is 41 degrees to 46. It is an illumination device characterized by the degree.

(Appendix 7) In the illumination device according to any one of appendices 3 to 6,
The illumination device is characterized in that the pitch between the grooves becomes narrower as the distance from the light source increases.

(Appendix 8) In the illumination device according to any one of appendices 3 to 7,
The illumination device is characterized in that the depth of the groove increases as the distance from the light source increases.

(Appendix 9) In the illumination device according to any one of appendices 3 to 8,
The pitch between the said grooves is 0.2 mm or less. The illumination apparatus characterized by the above-mentioned.

(Appendix 10) In the illumination device according to any one of appendices 1 to 9,
The light guide plate has a polygonal shape with a number of corners corresponding to the number of the plurality of light sources.

(Appendix 11) In the illumination device according to any one of appendices 1 to 10,
The illumination device, wherein the side surface of the light guide facing the light emitting surface of the light source is flat.

(Supplementary note 12) In the illumination device according to any one of supplementary notes 1 to 11,
An illumination device further comprising a lens sheet disposed on the other surface side of the light guide plate.

(Supplementary note 13) In the illumination device according to supplementary note 12,
The illumination device according to claim 1, wherein the lens sheet is a lens array sheet in which a plurality of spherical lenses are arranged in a lattice shape.

(Supplementary note 14) In the illumination device according to supplementary note 12,
The illumination device according to claim 1, wherein the lens sheet is obtained by bonding two lenticular lens sheets in which a plurality of cylindrical lenses are arranged in parallel so that the cylindrical lenses intersect each other.

(Supplementary note 15) In the illumination device according to supplementary note 12,
The illumination device, wherein the lens sheet is a light diffusion sheet including a diffusion material that diffuses light.

(Supplementary Note 16) The light guide plate includes a flat light guide plate, and a plurality of light sources that are arranged so that a light emitting surface faces the side surface of the light guide plate and allows light to enter the light guide plate from the side surface. A prism that is disposed on one surface of the light guide plate so as to surround a central portion of the light guide plate, reflects light emitted from the plurality of light sources and propagates through the light guide plate, and is emitted from the other surface of the light guide plate The prism is configured such that, for each of the plurality of light sources, the light emitted from the light source is transmitted to the other light source in a region facing the light source across the central portion of the light guide plate. An illumination device formed to emit from the surface;
An electronic apparatus comprising: a control device that controls the light source of the illumination device.

(Supplementary Note 17) In the electronic device according to Supplementary Note 16,
The plurality of light sources are formed on a circuit board on which the control device is formed,
The electronic device, wherein the light guide plate is disposed on the circuit board on which the plurality of light sources are formed.

(Supplementary note 18) In the electronic device according to supplementary note 16 or 17,
The said light guide plate is integrally formed with exterior components. The electronic device characterized by the above-mentioned.

(Supplementary note 19) In the electronic device according to supplementary note 18,
The exterior component includes a diffusing material that diffuses light.

DESCRIPTION OF SYMBOLS 10 ... Illumination apparatus 20 ... Light guide plate 22 ... Opening part 24 ... Prism 26 ... Grooves 26a, 26b ... Slope 28 ... Light beam 30 ... LED
40 ... Lens sheet 42a ... Micro lens 42b ... Cylindrical lens 42c ... Diffusion material 50, 98 ... Exterior component 52 ... Exterior cover 54 ... Accessory 56 ... Recess 60 ... Control device 62 ... Receiver 64 ... Transmission source determination unit 66 ... Database 68 ... LED control device 70 ... alert information storage unit 72 ... alert necessity determination unit 80 ... mobile phone 82 ... first housing 84 ... second housing 86 ... operation unit 88 ... display unit 90 ... light emitting unit 92 ... circuit board 94 ... Liquid crystal display device 96 ... Mounting component 100 ... Adhesive material

Claims (15)

A flat light guide plate;
A plurality of light sources that are arranged such that a light emitting surface faces the side surface of the light guide plate, and incident light into the light guide plate from the side surface;
The light guide plate is disposed on one surface of the light guide plate so as to surround a central portion of the light guide plate, reflects light emitted from the plurality of light sources and propagates through the light guide plate, and is reflected from the other surface of the light guide plate. An outgoing prism is formed,
The prism emits the light emitted from the light source to each of the plurality of light sources from the other surface in a region facing the light source across the central portion of the light guide plate. An illumination device characterized by being formed. The illumination device according to claim 1,
The prism does not emit the light emitted from the light source to each of the plurality of light sources from the other surface in a region between the light source and the central portion of the light guide plate. An illumination device characterized by being formed. The illumination device according to claim 1 or 2,
The prism includes a plurality of ring-shaped grooves arranged concentrically. The illumination device according to claim 1 or 2,
The prism has a spiral groove. An illumination device, wherein: The illumination device according to claim 3 or 4,
The groove is formed by a V-shaped groove having a first slope located on the side surface side of the light guide plate and a second slope located on the center portion side of the light guide plate. Illumination device characterized. The illumination device according to claim 5, wherein
The angle formed between the one surface of the light guide plate and the first inclined surface is 1 to 5 degrees, and the angle formed between the one surface of the light guide plate and the second inclined surface is 41 degrees to 46. It is an illumination device characterized by the degree. The illumination device according to any one of claims 3 to 6,
The illumination device is characterized in that the pitch between the grooves becomes narrower as the distance from the light source increases. The illumination device according to any one of claims 3 to 7,
The illumination device is characterized in that the depth of the groove increases as the distance from the light source increases. The illumination device according to any one of claims 3 to 8,
The pitch between the said grooves is 0.2 mm or less. The illumination apparatus characterized by the above-mentioned. The illumination device according to any one of claims 1 to 9,
The illumination device, wherein the side surface of the light guide facing the light emitting surface of the light source is flat. The illumination device according to any one of claims 1 to 10,
An illumination device further comprising a lens sheet disposed on the other surface side of the light guide plate. One surface of the light guide plate, comprising: a flat light guide plate; and a plurality of light sources that are arranged such that a light emitting surface faces the side surface of the light guide plate, and inject light into the light guide plate from the side surface And a prism that is disposed so as to surround a central portion of the light guide plate, reflects light emitted from the plurality of light sources and propagates through the light guide plate, and is emitted from the other surface of the light guide plate. The prism emits the light emitted from the light source to each of the plurality of light sources from the other surface in a region facing the light source across the central portion of the light guide plate. The illumination device being formed, and
An electronic apparatus comprising: a control device that controls the light source of the illumination device. The electronic device according to claim 12, wherein
The plurality of light sources are formed on a circuit board on which the control device is formed,
The electronic device, wherein the light guide plate is disposed on the circuit board on which the plurality of light sources are formed. The electronic device according to claim 12 or 13,
The said light guide plate is integrally formed with exterior components. The electronic device characterized by the above-mentioned. The electronic device according to claim 14, wherein
The exterior component includes a diffusing material that diffuses light.

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