JP2006278096A - Illumination device, electro-optical device, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electro-optical device provided with an illumination device capable of surely and easily adjusting the balance of illumination light at front side and back side and contributing to reduction of the thickness of a portable electronic apparatus. <P>SOLUTION: The electro-optical device 100 is constituted of of a light emitting body 11 integrally composed of a first light emitting element 11a, a second light emitting element 11b, a first light emitting face 11e emitting the light from the first light emitting element, and a second light emitting face 11f emitting the light from the second light emitting element; a first light guide sheet 12 having an end face 12b arranged so as to face the first light emitting face; a second light guide sheet 13 having an end face 13b arranged so as to face the second light emitting face, laid on the first light guide sheet 12; and a light reflection layer 14 arranged between the first light guide sheet and the second light sheet, so as to closely contact with both light guide sheets. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an illumination device, an electro-optical device, and an electronic apparatus, and more particularly to a configuration suitable as an illumination device used for an electro-optical device.

  In general, a backlight is disposed behind the liquid crystal display device, and illumination light of the backlight is emitted as display light by passing through the liquid crystal display device. As the backlight, a light emitter such as an LED (light emitting diode) or a cold cathode tube is disposed on the side, a light guide plate having an end face disposed opposite to the light emitter is provided, and a light reflecting sheet is provided behind the light guide plate. Sidelight type backlights with a large number of are used. In such a backlight, light emitted from the light emitter is introduced into the light guide plate and gradually emitted from the surface of the light guide plate while propagating through the inside of the light guide plate, and substantially along the surface of the light guide plate. It is comprised so that uniform illumination intensity may be obtained.

  By the way, the conventional backlight is configured so that illumination light is emitted only on the side opposite to the side where the light reflecting sheet is disposed. When it is necessary to illuminate both sides of the backlight, such as when configuring a portable electronic device, it is necessary to provide two backlights, which makes it difficult to reduce the thickness. Therefore, a double-sided light emission type backlight including a light guide plate configured to emit light on both sides is known (see, for example, Patent Documents 1 to 4 below).

In addition, as a double-sided light emitter for use in a display device such as a signboard, a linear light emitter is disposed opposite to the end surfaces of two light guide plates laminated with a light reflecting sheet interposed therebetween, and surrounds the end surfaces of the light guide plate and lines. There is known one in which a light reflection plate that collects light of a light emitter on the end face of a light guide plate is installed (see, for example, Patent Document 5 below).
JP 2004-46050 A JP 2004-55528 A JP 2004-87409 A JP 2004-144990 A JP-A-10-187075

  However, it is difficult to ensure the balance of the illumination light emitted to the front and back in the double-sided light emitting backlight having the single light guide plate described above, depending on the shape of the light guide plate and the optical characteristics of the transflective sheet. Since the illuminance of the illumination light changes, the manufacturing cost increases to ensure reproducibility, and it is difficult to adjust the balance of the illumination light on the front and back sides.

  In addition, the double-sided light emitter described above can provide a relatively thin structure for use in a large display device such as a signboard, but a linear light emitter such as a cold cathode tube can be used for a portable display device such as a mobile phone. When it is used for the above, it has an extremely large diameter, and is not a size that can contribute to thinning of the portable electronic device. Therefore, there is a problem that it is difficult to reduce the thickness of the portable electronic device. Further, in this double-sided light emitter, two light guide plates are arranged with a light reflection layer in between. However, since it is difficult to adjust the amount of light introduced from the linear light emitter into the two light guide plates, There is also a problem that it is difficult to adjust the balance of the illumination light.

  Accordingly, the present invention solves the above-described problems, and can be used to reliably and easily balance the illumination light on the front and back sides, as well as an electric device equipped with an illumination device that can contribute to a reduction in the thickness of a portable electronic device. It is to provide an optical device.

  In view of such circumstances, the electro-optical device of the present invention includes a first light emitting element, a second light emitting element, a first light emitting surface that emits light of the first light emitting element, and the second light emitting element. A light emitter integrally including a second light emitting surface for emitting light of the light emitting element, a first light guide sheet having an end face disposed opposite to the first light emitting surface, and the second A second light guide sheet provided with an end face opposed to the light emitting surface and disposed so as to overlap the first light guide sheet; and between the first light guide sheet and the second light guide sheet. And a light reflection layer arranged closely.

  According to this invention, the first light-emitting element and the second light-emitting element are provided in an integrated light-emitting body, and the end surface is disposed so as to face the first light-emitting surface that emits light from the first light-emitting element. The first light guide sheet, the light reflecting layer, and the second light guide sheet having an end face disposed opposite to the second light emitting surface that emits the light of the second light emitting element. Since the lighting device is configured by the laminated structure, the device can be thinned, the lighting system including the first light emitting element and the first light guide sheet, the second light emitting element, and the second light emitting element. Since the illumination system composed of the light guide sheet can be set separately, the front and back illumination states can be adjusted and set independently.

  In this invention, it is preferable that the said 1st light guide sheet and the said 2nd light guide sheet are comprised so that light may be radiate | emitted from the surface facing the surface adjacent to the said light reflection layer. Thus, a double-sided light emitter that emits illumination light from both front and back surfaces can be configured.

  In the present invention, it is preferable that the first light emitting surface and the second light emitting surface are provided side by side on the same plane. According to this, each end surface of the 1st light guide sheet and the 2nd light guide sheet which were arranged by laminating | stacking by providing a 1st light-projection surface and a 2nd light-projection surface along with the same plane. Therefore, the entire apparatus can be made compact.

  In the present invention, it is preferable that the luminance or emission wavelength distribution of the first light emitting element and the second light emitting element are different from each other. According to this, since the brightness | luminance or light emission wavelength distribution of a 1st light emitting element and a 2nd light emitting element differs mutually, the illumination aspect of front and back can be varied according to an illumination object.

  In the present invention, it is preferable that an emission angle distribution of light emitted from the first light emission surface and an emission angle distribution of light emitted from the second light emission surface are different from each other. Since the emission angle distribution of the light emitted from the first light emission surface and the emission angle distribution of the light emitted from the second light emission surface are different from each other, the first light guide sheet and the second light guide are provided. The radiation state of the illumination light of the sheet can be different.

  In the present invention, a height range of the first light exit surface is disposed within a thickness range of the end surface of the first light guide sheet, and a height range of the second light exit surface is the second range. It is preferable that the light guide sheet is disposed within the thickness range of the end face. According to this, the height ranges of the first light emission surface and the second light emission surface are arranged within the thickness ranges of the end surfaces of the corresponding first light guide sheet and second light guide sheet, respectively. Thus, the light emitted from the first light emitting surface and the second light emitting surface can be efficiently incident on the respective end surfaces of the first light guide sheet and the second light guide sheet. Therefore, the light use efficiency of the light emitter can be increased.

  In the present invention, the emission angle distribution of the light emitted from the first light emission surface is biased to the opposite side to the second light guide sheet, and the emission angle distribution of the light emitted from the second light emission surface is It is preferable that the first light guide sheet is biased to the opposite side. According to this, since the emission angle distribution of the light emitted from each light exit surface is biased toward the illumination light emission surface side of each light guide sheet, the propagation of the light entering each light guide sheet Since the direction can be biased toward the emission surface, the light utilization efficiency can be improved as a whole.

  In the present invention, the end surface of the first light guide sheet is inclined toward the second light output surface, and the end surface of the second light guide sheet is inclined toward the first light output surface. Preferably it is. According to this, since the end surface of each light guide sheet is inclined toward the other light exit surface side, the propagation direction of the light incident in each light guide sheet is changed to the emission surface side of each light guide sheet. Therefore, it is possible to increase the light utilization efficiency as a whole.

  In each of the above inventions, the light emitter is preferably an LED having a flat outer surface including the first light emitting surface and the second light emitting surface. According to this, it becomes possible to further reduce the thickness of the device by facilitating the downsizing of the light emitter.

  Moreover, it is preferable that each of the first light guide sheet and the second light guide sheet is made of a resin sheet having a thickness of 350 μm or less. As a result, it is possible to configure a lighting device that is extremely thin as compared with a lighting device using a conventional light guide plate.

  Furthermore, it is preferable that the light reflection layer is formed of a light reflection film. The light reflecting layer can be constituted by a thin film or the like attached to the surface of the first light guide sheet or the second light guide sheet, and the first light guide sheet and the second light guide sheet; Is made up of an independent light-reflecting film, which eliminates the need for film-forming processes such as thin film formation, does not significantly affect assembly operations, and facilitates component management, thus reducing manufacturing costs. In addition, the manufacturing process can be easily managed.

  Moreover, the thickness of the first light guide sheet and the second light guide sheet may be different from each other. In this case, it is possible to control the light quantity balance of the illumination light on both the front and back surfaces by making the thicknesses of the first light guide sheet and the second light guide sheet different.

  Furthermore, it is preferable that a low reflection region having a lower reflectance than the others is provided on a part of the front surface or the back surface of the light reflection layer. According to this, by providing the low reflection region, it is possible to adjust the distribution of light emitted from the surface of the light guide sheet. Here, the low reflection region may have a light absorption surface with a higher light absorption rate than others, or may have a light transmission surface with a higher light transmittance than others. Absent.

  Next, an electro-optical device according to the present invention includes any one of the illumination devices described above and an electro-optical panel arranged above the surface of the first light guide sheet.

  In the present invention, another electro-optical panel may be disposed above the surface of the second light guide sheet. In this case, it is desirable to match the formation region and distribution of the light reflection surface on the second light guide sheet side in the light reflection layer with the display region of another electro-optical panel.

  In the present invention, a light-transmitting operation unit may be disposed above the surface of the second light guide sheet. In this case, it is desirable to match the formation region and distribution of the light reflecting surface on the second light guide sheet side in the light reflecting layer with the shape and arrangement of the light transmissive operation unit.

  In the present invention, the laminated structure of the first light guide sheet, the second light guide sheet, and the light reflecting layer has flexibility, and is installed in a state where at least a partial region of the planar shape is curved. It is preferable. By making the above laminated structure flexible and installing it in a state where at least a part of the planar shape is curved, it becomes possible to install it in an appropriate posture according to the internal structure of the mounted device. Therefore, it is possible to reduce the size and thickness of the mounted equipment. In particular, since the laminated structure is curved so as to avoid other members, the space efficiency at the time of installing the lighting device can be increased, which can greatly contribute to the downsizing and thinning of the mounted equipment. .

  In this invention, it is preferable that the surface layer part of a said 1st light guide sheet or a said 2nd light guide sheet has a light-diffusion function. Since these light guide sheets have a light diffusing function, it is not necessary to separately install a light diffusing plate, so that the electro-optical device can be further reduced in thickness. Here, the light diffusing function can be configured by making the surface, which is the light emitting surface of the light guide sheet, a surface (rough surface) having fine irregularities.

  Next, an electronic apparatus according to an aspect of the invention includes the electro-optical device according to any one of the above, and a control unit that controls the electro-optical device. Examples of the electronic device include a display monitor device and a computer device. In particular, a portable electronic device such as a mobile phone, a portable information terminal, and an electronic watch is preferable.

[First Embodiment]
Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a partial cross-sectional view of a lighting device 10 according to a first embodiment of the present invention, FIG. 2A is a longitudinal cross-sectional view of a light emitter 11, and FIG. 2B is a front view seen from a light emitting direction. is there. The illumination device 10 includes a light emitter 11, a first light guide sheet 12, a second light guide sheet 13, and a light reflection layer 14.

  As shown in FIGS. 1 and 2, the light emitter 11 is a surface-mount type LED (light emitting diode) packaged in a rectangular parallelepiped (cubic) shape, and light emitting elements 11a and 11b each composed of a light emitting diode chip. The light emitting elements 11a and 11b have a package 11c, a transparent resin 11d filled around the light emitting elements 11a and 11b, and light emitting surfaces 11e and 11f from which the transparent resin 11d is exposed. On one outer surface of a rectangular parallelepiped (cube) of the light emitter 11, an opening of the accommodation space of the light emitting element 11a and an opening of the accommodation space of the light emitting element 11b are arranged side by side, and the light emitting elements 11a and 11b are respectively arranged. When the transparent resin 11d is filled in the storage spaces provided in the above, these openings constitute the light emitting surfaces 11e and 11f. That is, in the case of this embodiment, the light emission surfaces 11e and 11f are constituted by the surface of the transparent resin 11d. The light emission surfaces 11e and 11f are flat surfaces (preferably mirror-like smooth surfaces).

  The package 11c is made of a heat-resistant polymer resin (white resin) or the like, and its inner surface functions as a light reflecting surface. That is, it functions as a reflecting mirror that reflects the light emitted from the light emitting element 11a toward the end surface 12b of the light guide sheet 12, and reflects the light emitted from the light emitting element 11b toward the end surface 13b of the light guide sheet 13. It is configured to function as a reflecting mirror. Specifically, the inner surface of the package 11c is a mirror-like smooth surface and includes a concave curved surface facing the end surfaces 12b and 13b. The transparent resin 11d can be an acrylic resin or an epoxy resin. Further, two sets of terminal pairs (not shown) respectively connected to the light emitting elements 11a and 11b are provided on the outer surface of the light emitter 11 other than the light emitting surfaces 11e and 11f, and are separately provided for the light emitting elements 11a and 11b. Is configured so that the light emitting elements 11a and 11b can be controlled independently.

  The light guide sheets 12 and 13 are each composed of a thin sheet such as an acrylic resin. These thicknesses t are preferably 350 μm or less. In particular, it is desirable that the thickness t is in the range of 20 to 250 μm in order to facilitate the manufacture of the sheet and to ensure the light guide characteristics.

  It is preferable that the light guide sheets 12 and 13 substantially transmit light in a wavelength region used as illumination light (for example, light in the visible light region) among the light emitted from the light emitter 11. In other words, it is desirable to be made of a transparent material having a light transmittance of 80% or more, preferably 85% or more with respect to the light in the region.

  Further, the light is emitted from the surface 12a of the light guide sheet 12 (surface opposite to the surface in contact with the light reflection layer 14) and the surface 13a of the light guide sheet 13 (surface opposite to the surface in contact with the light reflection layer 14). It is preferable that the illuminance of the light to be transmitted is substantially uniform over the entire surface. For example, as the light emitting structure, a surface uneven shape, which will be described later, whose distribution density gradually changes from the light emitter 11 side to the opposite side is formed on the surfaces 12a and 13a. This light emitting structure may be provided only on a part of the surfaces 12a and 13a of the light guide sheet 12 and the light guide sheet 13 corresponding to the area where illumination is required.

  An end surface 12 b of the light guide sheet 12 is disposed to face the light emitting surface 11 a of the light emitter 11. Further, the height range of the light emitting surface 11 a is disposed within the thickness range of the end surface 12 b of the light guide sheet 12. On the other hand, the end surface 13 b of the light guide sheet 13 is disposed to face the light emitting surface 11 d of the light emitting body 11. Further, the height range of the light emitting surface 11 b is disposed within the thickness range of the end surface 13 b of the light guide sheet 13. As a result, almost all of the light emitted from the light emitting surface 11a is incident on the end surface 12b of the light guide sheet 12, and almost all of the light emitted from the light emitting surface 11b is incident on the end surface 13b of the light guide sheet 13. It is like that.

  In addition, the light guide sheet 12, the light reflection layer 14, and the light guide sheet 13 are stacked in a state of being in close contact with each other. In the case of this embodiment, the end surfaces 12b and 13b are flat surfaces (preferably mirror-like smooth surfaces). The end faces 12b and 13b may be disposed in close contact with the light emitting surfaces 11e and 11f of the light emitter 11.

  The light reflecting layer 14 may be a thin film deposited on the back surfaces of the light guide sheet 12 and the light guide sheet 13 (the surface opposite to the front surfaces 12a and 13a). It is preferable that the light reflection film is a separate body from the light sheet 13. Examples of the light reflecting film include a metal foil such as an aluminum foil, a laminated film provided with a metal thin film such as aluminum or chromium on a transparent resin film, and a white resin film such as a polyester film. Thus, by making the light reflecting layer 14 a film separate from the light guide sheets 12 and 13, film formation is not necessary, and parts management at the time of manufacture is facilitated, and the assemblability is also hindered. Since it is not given, the manufacturing cost can be reduced.

  In the illumination device 10, light emitted from the light emitter 11 is incident from the end faces 12b and 13b and propagates through the light guide sheet 12 and the light guide sheet 13 to the right side in the figure, and part of the light is a light reflection layer. While being reflected by the surface 14, the light is gradually emitted from the surfaces 12 a and 13 a as illumination light. At this time, a certain degree of dispersibility (uniformity) of illumination light is ensured by the above-described surface irregularities provided on the surfaces 12a and 13a. That is, of the light incident on the light guide sheet 12 and the light guide sheet 13 from the light emitter 11, light having a small angle difference with the surfaces 12a and 13a is totally reflected by the surfaces 12a and 13a. Although not emitted from 12a, 13a, but a light component is emitted as illumination light without being totally reflected by the surface uneven structure, the brightness of the surfaces 12a, 13a is set by appropriately setting the density distribution of the surface uneven structure. It is possible to make the distribution uniform or to set a desired distribution.

  As specific dimensions of the present embodiment, the height of the light emitting surfaces 11e and 11f of the light emitter 11 is about 0.1 to 0.4 mm, and the thickness t of the light guide sheet 12 and the light guide sheet 13 is 100 respectively. It is preferable that the thickness of the light reflecting layer 14 is about 5 to 100 μm.

  Conventionally, since a light guide plate having a thickness of at least about 0.5 to 0.6 mm was used, the thickness of the entire lighting device was limited to about 1.1 to 1.5 mm. In the form, the total thickness can be about 0.25 to 0.8 mm, and the thickness can be significantly reduced as compared with the conventional structure. In particular, since the thickness of a small liquid crystal panel in recent years has become extremely thin at around 1.0 mm, the influence of thinning the lighting device 10 is extremely large.

  Further, as the light emitter 11, a small chip-shaped LED having a thickness of about 0.6 mm is currently available, and it is also possible to have a structure including two light emitting elements. By disposing two light guide sheets having a thickness of about 200 to 300 μm on both sides of the light reflection layer, it is possible to configure a very thin lighting device corresponding to the single LED.

  The light emitter 11 of the present embodiment includes two light emitting elements 11a and 11b arranged side by side in the thickness direction of the light guide sheets 12 and 13 in an integrated package 11c, respectively, and has a two-layer light emitting structure as a whole. Therefore, the light emitted from the independent light emitting elements 11a and 11b can be separately incident on the light guide sheets 12 and 13, respectively. Therefore, since the light quantity incident on the light guide sheets 12 and 13 and the wavelength distribution of light can be set independently, the illumination radiated from the front surface 12a of the light guide sheet 12 and the front surface 13a of the light guide sheet 13 to both the front and back sides. The illuminance and wavelength distribution of light can be set independently. That is, an optimal illumination state can be set according to the illumination objects on the front and back sides.

[Second Embodiment]
Next, referring to FIG. 3, a lighting device 10 ′ according to a second embodiment of the present invention will be described. FIG. 3 is a partial cross-sectional view of this embodiment. In this embodiment, the light emitter 11 and the light reflecting layer 14 are the same as those in the first embodiment, and thus the description thereof is omitted. This embodiment is different from the first embodiment in that the thickness t2 of the light guide sheet 12 'and the thickness t3 of the light guide sheet 13' are different from each other, but other than the light guide sheets 12 'and 13'. Since the configuration is the same as that of the first embodiment, the description thereof is also omitted in these similar points.

  In the illustrated example, the thickness t2 of the light guide sheet 12 'is larger than the thickness t3 of the light guide sheet 13'. The end surface 12b 'of the light guide sheet 12' and the end surface 13b 'of the light guide sheet 13' are disposed to face the light emitting surface 11e and the light emitting surface 11f of the light emitter 11, respectively. The height of the end surface 12b ' Is larger than the height of the end face 13b ′, so that not only the light emitted from the light emitting surface 11e but also the light emitted from the light emitting surface 11f is incident on the inside of the light guide sheet 12 ′. Since only a part of the light emitted from the light exit surface 11f is incident on the inside of 13 ', the amount of light incident on the light guide sheet 12' is the amount of light incident on the light guide sheet 13 '. Bigger than. As a result, the luminance of the surface 12a ′ of the light guide sheet 12 ′ is greater than the luminance of the surface 13a ′ of the light guide sheet 13 ′. That is, the illuminance due to the illumination light emitted upward in the figure is larger (brighter) than the illuminance due to the illumination light emitted downward in the figure.

  As in this embodiment, by making the thickness t2 of the light guide sheet 12 'and the thickness t3 of the light guide sheet 13' different from each other, the luminance or illuminance in the upper and lower directions can be adjusted, The brightness balance or the illuminance balance can be set as appropriate.

  Moreover, in this illuminating device 10 ', since only the first light guide sheet 12' and the second light guide sheet 13 'need only be laminated, different light guide sheets with different thicknesses can be easily replaced. If a plurality of light guide sheets having different thicknesses are prepared in advance, it does not take time to adjust the illuminance balance.

[Third Embodiment]
Next, an illumination device 10 ″ according to a third embodiment of the present invention will be described with reference to FIG. 4. FIG. 4 is a partial cross-sectional view of the illumination device 20. In this embodiment, the light emitter 11 and the light guide. Since the sheets 12 and 13 can be configured in the same manner as in the first embodiment, description thereof will be omitted.

  In the present embodiment, the light reflecting layer 14 'can be made of the same material as in the above embodiments, but in the previous embodiment, the light reflecting layer 14 has a light reflecting surface entirely. On the other hand, a part of the surface of the light reflecting layer 14 ′ (a part of the surface in contact with the light guide sheet 13 in the illustrated example) is a light reflecting surface 14 x provided in another part. A low reflection region 14y having a lower light reflectivity is provided. The low reflection region 14y can be formed of a light absorption surface having a light absorption rate higher than that of the light reflection surface 14x, for example, formed of black resin or the like. As a result, light is less likely to be reflected in the low reflection region 14y than the light reflection surface 14x, and thereby the distribution of illumination light emitted from the surface 13a of the light guide sheet 13 can be changed (increase variation).

  In the present embodiment, the distribution of illumination light is varied by partially changing the light reflectance of the surface of the light reflecting layer 14. As a result, if there are areas that do not require illumination light (areas that interfere with the presence of illumination light) and areas that require illumination light, the illuminance distribution of the illumination device 10 ″ is adjusted to these areas. It becomes possible to control and adjust.

  In addition, as said low reflection area | region 14y, you may form the light absorption surface whose light absorptivity is higher than the light reflection surface 14x as mentioned above, For example, a light transmittance is higher than the light reflection surface 14x. A light transmission surface may be formed. Even in this case, since a certain amount of light can pass between the light guide sheet 12 and the light guide sheet 13 in the low reflection region 14y, the illuminance of the part can be made different from other parts. It becomes possible.

[Fourth Embodiment]
Next, with reference to FIG.5 and FIG.6, 4th Embodiment of the illuminating device based on this invention is described. The illuminating device 20 of this embodiment is the same as the previous embodiment in that it includes the light emitter 21, the light guide sheets 22 and 23, and the light reflecting layer 24, and is the same as described above unless otherwise specified. Since the configuration is provided, description of similar parts is omitted.

  Similarly to the above, the light source 21 has a two-layer structure including light emitting elements 21a and 21b, a package 21c, a transparent resin 21d, and light emitting surfaces 21e and 21f. The light source 21 is different from the light source 11 in that at least one of the emission angle distributions of the light emitted from the light emitting surfaces 21e and 21f of the light emitting elements 21a and 21b is biased in the thickness direction of the light guide sheets 22 and 23. The difference in both emission angle distributions seen in the thickness direction of the light guide sheets 22 and 23 is different from each other.

  More specifically, the emission angle distribution of the light emitted from the light emitting element 21 a from the light exit surface 21 e is biased toward the light guide sheet 22 on the side opposite to the light guide sheet 23. That is, the light emitted from the light emitting surface 21e is configured to have a peak on the side obliquely upward in the figure (on the surface 12a side). The emission angle distribution of the light emitted from the light emitting element 21 b from the light emitting surface 21 f is biased toward the light guide sheet 23 on the side opposite to the light guide sheet 22. That is, the light emitted from the light emitting surface 21f is configured to have a peak on the side which is inclined obliquely downward (surface 13a side) in the figure.

  The deviation of the emission angle distribution described above is caused by the portions 21 s and 21 t provided on the both sides in the thickness direction of the light guide sheets 22 and 23 on the reflective surface (the inner surface of the package 21 c) configured inside the light emitter 21. It is formed by inclining toward the surfaces 22a and 23a. The inclination of the reflective surface portions 21s and 21t may be realized by forming another reflective layer inside the accommodation space of the light emitting elements 21a and 21b.

  As the degree of the deviation of the emission angle, it is preferable that the peak of the emission angle is inclined within the range of 1 to 5 degrees in the thickness direction of the light guide sheets 22 and 23, and particularly 2.5 to 3 It is desirable to incline within a range of 5 degrees. If it is less than 1 degree, the effect of improving the light utilization efficiency due to the bias cannot be obtained, and if it exceeds 5 degrees, the light emitted from the light exit surface is introduced into the light guide sheets 22 and 23. The ratio decreases, and the light utilization efficiency decreases.

  In the present embodiment, the end surface 22b of the light guide sheet 22 disposed to face the light emitting surface 21e is inclined toward the light emitting surface 21f, and the end surface 23b of the light guide sheet 23 disposed to face the light emitting surface 21f. Is inclined toward the light exit surface 21e. The inclination angle in the thickness direction of the end faces 22b and 23b is preferably in the range of 1 to 5 degrees, and more preferably in the range of 2.5 to 3.5 degrees. If the angle is less than 1 degree, the effect of improving the light utilization efficiency due to the inclination cannot be obtained. If the angle exceeds 5 degrees, the ratio of the light emitted from the light exit surface is introduced into the light guide sheets 22 and 23. And the light utilization efficiency decreases.

  In the present embodiment configured as described above, most of the light emitted from the light emitting surfaces 21e and 21f proceeds obliquely toward the surface 22a and 23a toward the light guide sheets 22 and 23, and the end surface 22b. , 23b. Since the end surfaces 22b and 23b are also inclined as described above, the incident light is refracted further toward the surfaces 22a and 23b at the end surfaces 22b and 23b, and enters the light guide sheets 22 and 23. In this way, the path of light incident from the end faces 22b and 23b is biased toward the front surfaces 22a and 23a in the respective light guide sheets 22 and 23 as a whole, so that more light is emitted from the light emitter 21. This component can be used as illumination light emitted from the surfaces 22a and 23a, so that it is possible to increase the light use efficiency of the entire illumination device.

[Fifth Embodiment]
Next, the configuration of the electro-optical device 100 according to the present invention will be described with reference to FIGS. FIG. 7 is a schematic longitudinal sectional view showing a schematic configuration of the present embodiment, and FIG. 8 is a plan layout view of the same embodiment. Although the present embodiment shows an example using the above-described lighting device 10, in reality, any of the lighting devices described above may be used. The electro-optical device 100 includes the above-described illumination device 10, an electro-optical panel 110 disposed on the surface of the light guide sheet 12 of the illumination device 10, and an electro-optical panel 120 disposed on the surface of the light guide sheet 13. And.

  In this embodiment, the electro-optical panel 110 is a liquid crystal panel, in which substrates 111 and 112 are bonded together with a sealing material 113, and a liquid crystal 114 is sealed therebetween. Further, polarizing plates 115 and 116 are disposed on the outer surfaces of the substrates 111 and 112 (the surface opposite to the inner surface facing the liquid crystal 114) by a method such as sticking.

  On the other hand, the electro-optical panel 120 is also a liquid crystal panel, in which substrates 121 and 122 are bonded together with a sealing material 123, and a liquid crystal 124 is sealed therebetween. Further, polarizing plates 125 and 126 are arranged on the outer surfaces of the substrates 121 and 122 by a method such as sticking.

  The electro-optical panel 110 is provided with a substrate overhanging portion 111e in which the substrate 111 extends outward from the outer shape of the substrate 112, and an input terminal (not shown) is formed on the substrate overhanging portion 111e. On the other hand, the flexible wiring board 130 is mounted.

  On the other hand, the electro-optical panel 120 is also provided with a substrate overhanging part 121e in which the substrate 121 projects outward from the outer shape of the substrate 122, and an input terminal (not shown) is formed on the substrate overhanging part 121e. A flexible wiring board 130 is mounted on the input terminal.

  The light emitting body 11 is further mounted on the flexible wiring board 130. In addition, the flexible wiring board 130 is provided with a connection terminal portion 131, and the connection terminal portion 131 is connected to a control circuit or the like of the mounted device. Note that the electro-optical panel 110 and a driving circuit (for example, a liquid crystal driver circuit) for driving the electro-optical panel 120 may be mounted on the flexible wiring board 130, and the driving circuit is provided in a part different from the panel to be flexible. You may make it connect with the wiring board 130. FIG.

  FIG. 8 shows a planar arrangement of the entire apparatus by superimposing a planar structure of each component of the electro-optical device 100. In the illuminating device 10, a plurality of light emitters 11 are arranged along one side of the light guide sheet 12, the light guide sheet 13, and the light reflecting layer 14 that are configured to have a rectangular shape in plan view. In addition, the electro-optical device 110 extends in a wider range than the outer shape of the electro-optical device 120, and the display area 110 </ b> A of the electro-optical device 110 is formed wider than the display area 120 </ b> A of the electro-optical device 120.

  In the present embodiment, as described above, the electro-optical device 110 has a wide display region 110A, whereas the electro-optical device 120 has a display region 120A that is narrower than the display region 110A. When the front and back display areas are different from each other as described above, in the conventional double-sided illumination device using a single light guide plate, the back electro-optical panel 120 is shadowed when the wide display area 110A of the electro-optical panel 110 is viewed. There is a problem that the visibility of the display area 110A deteriorates. However, in the present embodiment, since the light reflection layer 14 is provided in the lighting device 10, even if the sizes of the front and back electro-optical panels are different, they may be optically influenced by the back panel structure. Disappears and does not deteriorate visibility.

  In the present embodiment, the illumination device 10 is required to have an illumination range that covers a wide display area 110A for the electro-optical panel 110, whereas the illumination of the illumination device 10 is applied to the electro-optical panel. The range is narrower than the illumination range for the first electro-optical device 110 (display area 120A). Therefore, on the surface of the light reflecting layer 14 on the light guide sheet 13 side that illuminates the display region 120A, the region corresponding to the display region 120A is a light reflecting surface, and the outside of the region is a light reflecting surface such as a light absorbing surface. It may be a low rate surface. In this case, since the brightness of the illumination device 10 can be reduced in an area outside the illumination range corresponding to the display area 120A, a malfunction of the circuit due to unnecessary light or leakage of light from the inside of the mounted device to the outside. Can be prevented.

[Sixth Embodiment]
Next, the configuration of the electro-optical device 200 according to the present invention will be described with reference to FIGS. 9 and 10. FIG. 9 is a schematic longitudinal sectional view showing a schematic configuration of the present embodiment together with a part of the mounted device, and FIG. 10 is a plan layout view of the same embodiment. In the present embodiment, the case where the above-described illumination device 10 ″ is used is shown, but any of the illumination devices described above may actually be used. The electro-optical device 200 is the above-described illumination device 10. ”And an electro-optical panel 210 disposed on the surface of the light guide sheet 12 of the lighting device 10 ″.

  In this embodiment, the electro-optical panel 210 is a liquid crystal panel, in which substrates 211 and 212 are bonded together with a sealant 213, and a liquid crystal 214 is sealed therebetween. Further, polarizing plates 215 and 216 are disposed on the outer surfaces of the substrates 211 and 212 (the surface opposite to the inner surface facing the liquid crystal 114) by a method such as sticking.

  The electro-optic panel 210 is provided with a substrate overhanging portion 211e in which the substrate 211 projects outward from the outer shape of the substrate 212. The substrate overhanging portion 211e is provided with an input terminal (not shown) and the input terminal. On the other hand, a flexible wiring board 230 is mounted. The light emitting body 11 is mounted on the flexible wiring board 230, and a connection terminal portion 231 is provided.

  The electro-optical device 200 according to this embodiment is mounted on a thin portable electronic device such as a mobile phone described later. A case wall 50 is disposed on one side (the upper side in the drawing) of the mounting position of the electro-optical device 200, and the case wall 50 is fitted and fixed at a position substantially corresponding to the display area 210 </ b> A of the electro-optical panel 210. A display window 51 having a shape and size corresponding to the display area 210A is provided. In addition, a case wall 60 is disposed on the other side (lower side in the drawing) of the mounting position of the electro-optical device 200, and an operation unit made of a transparent or translucent material (resin material or the like) is provided on the case wall 60. (Operation button) 61 is attached in an operable manner.

  In the present embodiment, the surface of the light reflecting layer 14 ′ of the lighting device 10 ″ on the light guide sheet 12 side is a substantially continuous light reflecting surface, but the light reflecting layer 14 ′ on the light guide sheet 13 side. As described above, the light reflection surface 14x and the low reflection region (for example, light absorption surface) 14y having a lower light reflectivity are provided on the surface, which corresponds to the operation unit 61 in the illustrated example. Is provided with a light reflection surface 14x, and a portion corresponding to the portion of the case wall 60 other than the operation portion 61 is a low reflection region 14y.

  Thereby, the light that has entered the light guide sheet 13 and propagated through the light emitted from the light emitter 11 is emitted from the surface of the light guide sheet 13 at a portion corresponding to the light reflecting surface 14x, The position of the operation unit 61 can be notified to the user through the operation unit 61. On the other hand, since it becomes difficult to radiate | emit from the surface of the light guide sheet 13 in the part corresponding to the light absorption surface 14y, illumination light can be reduced in parts other than the operation part 61. FIG.

[Seventh Embodiment]
Next, an electro-optical device 300 according to a seventh embodiment of the invention will be described with reference to FIG. The electro-optical device 300 includes a light emitter 31, a light guide sheet 32, a light guide sheet 33, and a light reflection layer 34, which is basically configured in the same manner as the illumination devices of the first to fourth embodiments. The apparatus 30, the electro-optical panel 310 disposed on the surface of the first light guide sheet 32 of the lighting device 30, and the electro-optical panel 320 disposed on the surface of the light guide sheet 33 of the lighting device 30. Have.

  Each of the electro-optical panel 310 and the electro-optical panel 320 has the same basic structure as that of the fifth embodiment. In the case of this embodiment, the electro-optical panel 310 and the electro-optical panel 320 have a planar shape smaller than the light guide sheet 32 and the light guide 33 of the illumination device 30. The laminated structure of the light guide sheet 32, the light guide sheet 33, and the light reflection layer 34 is planar with these electro-optical panels between the light emitter 31 and the outer edges of the electro-optical panel 310 and the electro-optical panel 320. It has a flat part that does not overlap.

  The light guide sheet 32, the light guide sheet 33, and the light reflecting layer 34 of the present embodiment have flexibility. As a result, as shown in FIG. 11, among the light guide sheet 32, the light guide sheet 33, and the light reflecting layer 34, the electro-optic panel 310 and the planar portion that does not overlap the electro-optic panel 320 in a planar shape are arbitrarily formed. Can be bent. For example, as shown in the drawing, the laminated structure of the light guide sheet 32, the light guide sheet 33, and the light reflecting layer 34 has a height of the end surface portion facing the light emitter 31 and between the electro-optical panel 310 and the electro-optical panel 320. A step Dh can be formed between the height of the portion sandwiched between the two.

  In this case, in the light guide sheet 32 and the light guide sheet 33, light emission for emitting light of the above-described surface concavo-convex structure or the like only to a region overlapping the electro-optic panel 310 and the electro-optic panel 320 in a plane. Provide the structure, and do not provide the above light emitting structure so that the light incident from the light emitter 31 is not emitted from the surface to the outside in the plane portion that does not overlap the electro-optic panel 310 and the electro-optic panel 320 in a plane. Is preferred. As a result, the light incident from the light emitter 31 into the light guide sheet 32 and the light guide sheet 33 is the same as the principle of the optical fiber in the electro-optical panel 310 and the plane portion that does not overlap the electro-optical panel 320 in a plane. The light guide sheet 32 and the electro-optical panel 310 and the electro-optical panel 320 are gradually reached by the light-emitting structure when they reach a region that overlaps with the electro-optical panel 310 and the electro-optical panel 320. The light is emitted from the surface of the light guide sheet 33.

  With the above-described configuration, the storage shape of the electro-optical device 300 can be changed inside various mounted devices such as portable electronic devices, so that the mounted device can be configured compactly. . For example, in the example shown in FIG. 11, due to the presence of the step Dh, other members (circuits, electronic elements, etc.) can be disposed in the region S indicated by the dotted line in the figure, and the light emitter 31 and the flexible body on which the light emitter 31 is mounted. Since the accommodation efficiency can be increased by arranging the wiring board or the like in an empty space where no other member exists, the mounted device can be further reduced in size and thickness.

[Eighth Embodiment]
Next, with reference to FIG. 12, the structure of the light guide sheet and light guide sheet that can be used in each of the embodiments according to the present invention will be described. The light guide sheet 15 shown in FIG. 12A has an inclined surface 15x whose surface orientation toward the inside of the light guide sheet 15 is inclined to the side opposite to the light propagation direction P on the light emitting surface 15a. And the surface uneven | corrugated structure 15S provided with the inclined surface 15y inclined to the propagation direction P side of light is provided.

  Of the surface concavo-convex structure 15S, the inclined surface 15x functions as a light emitting surface for emitting internally propagating light to the outside. Therefore, the uniformity of the illumination light distribution radiated from the surface 15a of the light guide sheet 15 can be ensured by appropriately setting the density of the inclined surface 15x. For example, generally, the amount of light propagating through the inside of the light guide sheet 15 decreases as the distance from the light emitter (not shown) decreases. Therefore, it is preferable to increase the formation density or the area ratio of the inclined surface 15x accordingly.

  On the other hand, the light guide sheet 16 shown in FIG. 12B is provided with a surface uneven structure 16S substantially similar to the light guide sheet 15 on the surface 16a, but the inclined surface 16x has fine surface unevenness. It differs from the above in that it has a rough surface. Thus, since the inclined surface 16x is a rough surface, the uniformity of the illumination light emitted from the surface 16a can be further improved, and variations in illuminance distribution can be suppressed.

  That is, the light guide sheet 16 has not only a light guide function similar to that of the conventional light guide plate, but also a function of a light diffusing plate that is conventionally arranged separately from the light guide plate. This eliminates the need to separately arrange the light diffusing plate, so that the illumination device can be made thinner.

[Ninth Embodiment]
Finally, an embodiment of an electronic apparatus according to the present invention will be described with reference to FIGS. FIG. 13 is a schematic configuration diagram schematically showing the electro-optical device 100 mounted on the electronic apparatus of the present embodiment and its control part, and FIG. 14 is a schematic perspective view showing the appearance of the electronic apparatus of the present embodiment (a). ) And (b).

  As shown in FIG. 13, the electro-optical device 100 includes the illumination device 10 (backlight) described above, and the electro-optical panel 110 and the electro-optical panel 120 disposed on both sides thereof. The electro-optical panel 110 and the electro-optical panel 120 are respectively provided with driving circuits 110D and 120D configured by liquid crystal driver circuits and the like, and the driving circuits 110D and 120D are controlled by the control means 1100 and 1200 to drive. The circuits 110D and 120D are configured to drive the electro-optical panel 110 and the electro-optical panel 120 so that a desired image display is realized.

  The control means 1100 and 1200 include display information output sources 1110 and 1210, display processing circuits 1120 and 1220, power supply circuits 1130 and 1230, and timing generators 1140 and 1240, respectively.

  The display information output sources 1110 and 1210 are a memory composed of a ROM (Read Only Memory), a RAM (Random Access Memory), etc., a storage unit composed of a magnetic recording disk, an optical recording disk, etc., and a tuning that outputs a digital image signal in a synchronized manner. And display information in the form of an image signal of a predetermined format and the like based on various clock signals generated by the timing generators 1140 and 1240. .

  The display information processing circuits 1120 and 1220 include various known circuits such as a serial-parallel conversion circuit, an amplification / inversion circuit, a rotation circuit, a gamma correction circuit, and a clamp circuit, and execute processing of input display information. The image information is supplied to the drive circuits 110D and 120D together with the clock signal CLK. The drive circuits 110D and 120D include a scanning line drive circuit, a data line drive circuit, and an inspection circuit. The power supply circuits 1130 and 1230 supply predetermined voltages to the above-described components.

  In the present embodiment, a control command for the display information output sources 1110 and 1210 is sent from the main control unit 1000 and a control signal for the light emitter 11 is sent. The control content of the light emitter 11 by the main controller 1000 includes on / off control of the light emitter 11 and luminance control.

  As shown in FIG. 14, the electronic device 2000 includes an operation unit 2001 and a display unit 2002, and the operation unit 2001 and the display unit 2002 can be folded together. The display unit 2002 incorporates the electro-optical device 100, the display screen of the electro-optical panel 110 is disposed on the inner surface of the display unit 2002, and the display screen of the electro-optical panel 120 is disposed on the outer surface of the display unit 2002.

  When the electro-optical device 100 is mounted inside the display unit 2002 as in the present embodiment, the thickness of the display unit 2002 is determined by the thickness of the electro-optical device 100. In the electro-optical device 100 of the present embodiment, since the illumination device 10 can be configured to be extremely thin as described above, the electro-optical device 100 can also be thinned, and thereby the thickness of the display unit 2002 can be reduced. In particular, since the thickness of the display unit 2002 is usually about 8 to 12 mm, if the thickness of the lighting device 10 is reduced, for example, about 1 to 2 mm, the influence on the feeling of portability and operation is affected. Big and extremely effective.

  The electro-optical device, the electronic apparatus, or the illumination device of the present invention is not limited to the above-described illustrated examples, and various changes can be made without departing from the scope of the present invention. is there.

The partial cross section figure of the illuminating device of 1st Embodiment. The longitudinal cross-sectional view (a) and front view (b) of the light-emitting body used for the illuminating device of 1st Embodiment. The partial cross section figure of the illuminating device of 2nd Embodiment. The partial cross section figure of the illuminating device of 3rd Embodiment. The partial cross section figure of the illuminating device of 4th Embodiment. The longitudinal cross-sectional view (a) and front view (b) of the light-emitting body of the illuminating device of 4th Embodiment. FIG. 10 is a schematic cross-sectional view of an electro-optical device according to a fifth embodiment. FIG. 10 is a plan layout view of an electro-optical device according to a fifth embodiment. FIG. 10 is a schematic cross-sectional view of an electro-optical device according to a sixth embodiment. FIG. 10 is a plan layout view of an electro-optical device according to a sixth embodiment. FIG. 10 is a schematic cross-sectional view of an electro-optical device according to a seventh embodiment. The fragmentary sectional view (a) of the light guide sheet of 8th Embodiment and the fragmentary sectional view (b) of the modification. The schematic block diagram of the electronic device of 9th Embodiment. The schematic perspective views (a) and (b) of 9th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Illuminating device, 11 ... Luminescent body, 11a, 11b ... Light emitting element, 11e, 11f ... Light emission surface, 12, 13 ... Light guide sheet, 12a, 13a ... Surface, 12b, 13b ... End surface, 14 ... Light reflection layer , 100 ... electro-optical device, 110, 120 ... electro-optical panel, 130 ... flexible wiring board

Claims (14)

A first light emitting element, a second light emitting element, a first light emitting surface that emits light of the first light emitting element, and a second light emitting surface that emits light of the second light emitting element. A light emitter provided integrally;
A first light guide sheet having an end face disposed opposite to the first light exit surface;
A second light guide sheet provided with an end face opposed to the second light emitting surface and arranged to overlap the first light guide sheet;
A light reflecting layer closely disposed between the first light guide sheet and the second light guide sheet;
An illumination device comprising:   The lighting device, wherein the first light guide sheet and the second light guide sheet are configured to emit light from a surface facing a surface adjacent to the light reflection layer.   The lighting device according to claim 1, wherein the first light emission surface and the second light emission surface are provided side by side on the same plane.   4. The illumination device according to claim 1, wherein the first light-emitting element and the second light-emitting element have different luminances or emission wavelength distributions. 5.   The illumination device according to claim 3, wherein an emission angle distribution of light emitted from the first light emission surface and an emission angle distribution of light emitted from the second light emission surface are different from each other. . A height range of the first light exit surface is disposed within a thickness range of the end surface of the first light guide sheet;
6. The illumination according to claim 1, wherein a height range of the second light emitting surface is disposed within a thickness range of the end surface of the second light guide sheet. apparatus. The emission angle distribution of the light emitted from the first light exit surface is biased to the opposite side to the second light guide sheet,
The illumination angle distribution according to any one of claims 1 to 6, wherein an emission angle distribution of light emitted from the second light emission surface is biased to the opposite side to the first light guide sheet. apparatus. The end surface of the first light guide sheet is inclined toward the second light exit surface;
The lighting device according to claim 1, wherein the end surface of the second light guide sheet is inclined toward the first light exit surface.   9. An electro-optical device comprising: the illumination device according to claim 1; and an electro-optical panel disposed above a surface of the first light guide sheet.   The electro-optical device according to claim 9, wherein another electro-optical panel is disposed above the surface of the second light guide sheet.   The electro-optical device according to claim 9, wherein a light-transmitting operation unit is disposed above the surface of the second light guide sheet.   The laminated structure of the first light guide sheet, the second light guide sheet, and the light reflecting layer is flexible, and at least a part of the planar shape is curved so as to avoid other members. The electro-optical device according to claim 9, wherein the electro-optical device is installed.   The electro-optical device according to any one of claims 9 to 12, wherein a surface layer portion of the first light guide sheet or the second light guide sheet has a light diffusing function. An electronic apparatus comprising: the electro-optical device according to claim 9; and a control unit that controls the electro-optical device.

Images