JP2007047352A - Lighting device, display device, and data transfer method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for suppressing a rise in manufacturing cost by suppressing an increase in the number of components, and suppressing the number of wires and wire lengths, improving reliability, eliminating unnecessary radiation or reducing radiation noise and so on. <P>SOLUTION: A lighting device 110 of the present invention includes a light emitting element 111, a light guide body 112 which guides light emitted by the light emitting element 111 to project illumination light, a light emission control circuit 110X which performs modulation control while making the light emission type of the light emitting device 111 correspond to an input signal X1, a photodetector 116 which detects the light emitted by the light emitting element 111 and outputs a detection signal, and a receiving circuit 110Y which outputs an output signal X4 corresponding to the input signal X1 based upon the detection signal Y1 of the photodetector 116. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an illuminating device, a display device, and a data transfer method, and more particularly to a configuration of an illuminating device suitable for the case of being configured as a backlight unit of a liquid crystal display device.

  In general, a liquid crystal display device independently controls the light transmittance of each of a plurality of pixels by supplying predetermined potentials to signal electrodes and scanning electrodes formed on a liquid crystal display panel, thereby producing a desired image. It is configured so that it can be displayed.

  In recent years, with the increase in the number of pixels associated with higher definition of the liquid crystal display panel, the number of lines and the length of the wiring have increased, and the data transmission rate has been increasing. The unnecessary radiation from the wiring board (inverter, etc.) increases, and it is necessary to take measures such as the installation of filters and shielding materials in order to reduce this unnecessary radiation, which increases the manufacturing cost. is there.

Therefore, there is known a method of reducing unnecessary radiation of electromagnetic waves by supplying display data signals or the like using light signal transmission instead of supplying them via electric wires (wiring) (for example, the following) Patent Document 1). In this method, by using light for data transmission to a voltage applying element that supplies a driving potential, the above-described unnecessary radiation can be reduced and the number of wiring connection points can be reduced, so that highly reliable signal transmission can be realized. It is said that an effect is obtained.
Japanese Patent Laid-Open No. 2001-21913

  However, in the signal transmission using light described above, it is necessary to newly provide a light emitting means including a driver and a light emitting element, and it is necessary to configure a light guide for guiding light from the light emitting means to each voltage applying element. In this light guide path, it is necessary to provide a light guide path having a complicated optical structure for branching light in order to supply light to each of the plurality of voltage applying elements. For this reason, the number of parts increases and the structure becomes complicated, and there is a problem that the manufacturing cost increases.

  Therefore, the present invention can suppress an increase in manufacturing cost by suppressing an increase in the number of components, and also suppress the number of wires and wiring length, improve reliability, reduce unnecessary radiation, or reduce radiation noise. It is to provide a technology capable of achieving the above.

  In view of such circumstances, the illumination device of the present invention includes a light emitting element, a light guide that guides light emitted from the light emitting element and emits illumination light, and a light emitting mode of the light emitting element based on an input signal. A light emission control circuit that performs modulation control, a photodetector that detects light emitted from the light emitting element and outputs a detection signal, and an output signal corresponding to the input signal based on the detection signal of the photodetector And a receiving circuit for outputting.

  According to the present invention, the light emission mode of the light emitting element that emits light for forming the illumination light of the illumination device is modulated and controlled by the light emission control circuit in accordance with the input signal, and this light is detected by the photodetector. Since it is not necessary to provide a new light emitting element separately by obtaining the output signal in the receiving circuit, the number of wirings and the wiring length are reduced by light transmission, the reliability is improved, unnecessary radiation is reduced, or radiation noise is generated. It is possible to enjoy the advantages such as the reduction of the number of parts, and at the same time, it is possible to reduce the number of parts, the manufacturing cost, or the miniaturization.

  In this invention, it is preferable that the said photodetector is comprised so that the light guide | induced by the said light guide may be detected. According to this, since at least a part of the light guide path from the light emitting element to the light detector can be configured by the light guide, further reduction in the number of parts and miniaturization can be achieved.

  In the present invention, the light guide has a light incident surface on which light emitted from the light emitting element is incident and a light output surface that emits the illumination light, and the light is propagated to the inside while propagating the incident light. The illumination light is preferably emitted from the emission surface. According to this, by using the light guide configured to propagate the light inside, the illumination light emitted from the light exit surface is hardly affected, and the light is appropriately positioned with respect to the light guide. A detector can be arranged to detect light.

  In this invention, it is preferable that the said photodetector is opposingly arranged by the surface of the said light guide other than the said light-projection surface. According to this, it can comprise so that the illumination light radiate | emitted from a light guide body may be hardly influenced, and it is radiate | emitted from a light guide body by arrange | positioning a photodetector facing the surface of a light guide body. Since light can be directly detected, detection sensitivity can be increased. In addition, since it is not necessary to separately provide a light guide path for optical transmission, the number of parts can be further reduced and the size can be reduced.

  In the present invention, each of the light emitting elements emits light in a plurality of wavelength regions that are independently modulated and controlled, and the photodetector independently detects the amount of light in the plurality of wavelength regions, and the light emission The control circuit modulates and independently modulates the light emission modes of the light in the plurality of wavelength ranges emitted from the light emitting element, and the reception circuit detects the detection signal for each of the plurality of wavelength ranges of the photodetector. It is preferable to treat each of these. According to this, since optical transmission can be performed in parallel in each of a plurality of wavelength ranges, the transmission capacity can be increased.

  Next, a display device of the present invention includes the illumination device according to any one of the above and a display body illuminated by the illumination device. In this display device, light transmission can be performed by using the configuration of the lighting device, so that the advantages such as suppression of the number of wires and wiring length, improvement of reliability, reduction of unnecessary radiation, and the like by light transmission can be enjoyed. At the same time, the number of parts, the manufacturing cost, or the size can be reduced.

  In the present invention, it is preferable that the display body is an electro-optical device having a predetermined frame frequency, and a modulation frequency of a light emission mode of the light emitting element is larger than the frame frequency. According to this, by having a modulation frequency larger than the frame frequency of the electro-optical device, it is possible to reduce the influence on the display mode due to the variation of the illumination light of the illumination device. In particular, in order to eliminate the influence on the display quality, it is desirable to set so that the modulation frequency and the frame frequency do not interfere with each other.

  Next, the data transfer method of the present invention is parallel to performing illumination by using a lighting device including a light emitting element and a light guide structure that guides light emitted from the light emitting element to form illumination light. The data transmission is performed by modulating the light emission mode of the light emitting element according to an input signal, detecting the modulated light, and outputting an output signal corresponding to the input signal. To do.

  According to the present invention, it is not necessary to separately provide a new light emitting element, so that the advantages such as suppression of the number of wirings and wiring length by optical transmission, improvement of reliability, reduction of unnecessary radiation, and reduction of radiation noise can be enjoyed. At the same time, the number of parts, the manufacturing cost, or the size can be reduced.

  In the present invention, the light emission mode of the light emitting element is independently modulated for each of a plurality of wavelength ranges, and light detection and processing is performed for each of the plurality of wavelength ranges, thereby transferring data in parallel in the plurality of wavelength ranges. It is preferable to carry out. According to this, since optical transmission can be performed in parallel in each of a plurality of wavelength ranges, the transmission capacity can be increased.

[First Embodiment]
Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic cross-sectional view illustrating an example of a usage mode of the illumination device according to the first embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of the illumination device according to the first embodiment.

  The illumination device 110 according to the present embodiment includes a light emitting element 111 and a light guide plate 112. The light emitting element 111 is not particularly limited as long as it is a light source capable of controlling brightness such as an LED (light emitting diode). The light guide plate 112 is a plate-like body made of a transparent material such as acrylic resin. Here, the light emitted from the light emitting element 111 is incident on the light incident surface (end surface) 112a of the light guide plate 112 and propagates in the right direction in the drawing while traveling through the light guide plate 112 in the right direction in the figure. It comes out from. On the surface (lower surface) opposite to the light emitting surface 112b of the light guide plate 112, a reflecting plate 113 made of a white polycarbonate sheet or the like is disposed. A light diffusing plate 114 and a light collecting plate 115 are sequentially arranged on the light emitting surface 112b.

  In addition, a photodetector 116 made of a photodiode or the like is disposed on the end face of the illumination device 110. The photodetector 116 is configured to receive light propagating through the light guide plate 112 and output a detection signal corresponding to the amount of received light. The light detector 116 can be disposed at any position as long as it can detect light propagating through the light guide plate 112. However, as shown in the illustrated example, it is preferable that the light guide plate 112 is disposed to face the surface other than the light emitting surface 112b. In this way, the emission state of the illumination light emitted from the light guide plate 112 is hardly affected, and it is easy to secure an arrangement space for the photodetector 116 without increasing the size of the illumination device 110.

  As shown in FIG. 1, when configuring the display device 100, the electro-optical panel 120 is disposed at the tip of the light emitting surface 112 of the illumination device 110. In the illustrated example, the electro-optical panel 120 is a liquid crystal display body, in which transparent substrates 121 and 122 made of glass or the like are bonded together with a sealing material 123 and a liquid crystal 124 is sealed between the transparent substrates 121 and 122.

  A plurality of transparent electrodes 121 a are formed on the inner surface of the transparent substrate 121, and a plurality of transparent electrodes 122 a are also formed on the inner surface of the transparent substrate 122. A region where the transparent electrodes 121a and 122a face each other constitutes a pixel whose transmittance can be controlled independently. For example, when adopting a liquid crystal display mode such as TN or STN, the polarizing plates 125 and 126 are disposed on the outer surfaces of the transparent substrates 121 and 122.

  The electro-optical panel 120 is provided with a drive circuit 127 for supplying a drive potential to the transparent electrodes 121a and 122a. In the illustrated example, the drive circuit 127 is mounted on the transparent substrate 121. However, even if the drive circuit 127 is mounted on a wiring substrate (not shown) such as a flexible substrate connected to the electro-optical panel 120. Good.

  The electro-optical panel 120 is configured to receive illumination light emitted from the illumination device 110 and transmit the illumination light with a predetermined transmittance for each of the pixels to realize a desired display mode. The driving method of the electro-optical panel 120 may be static driving or active matrix driving. Usually, the frame frequency during display driving is about 60 to 70 Hz, and the driving circuit 127 supplies a driving potential to the transparent electrodes 121a and 122a according to this frame frequency.

  As shown in FIG. 2, the illumination device 110 generates an output signal in response to a light emission control circuit 110X that modulates and controls a light emission mode of the light emitting element 111 based on an input signal, and a detection signal of the photodetector 116. And a receiving circuit 110Y.

  The light emission control circuit 110X is based on the control signal X3, the data forming means 110A that forms the transmission data X2 based on the input signal X1, the control signal forming means 110B that forms the control signal X3 based on the transmission data X2, and the like. And a light emission driving means (light emitting element driving circuit) 110C for outputting a driving signal X4 for driving the light emitting element 111.

  For example, transmission data X2 to be transmitted by optical transmission is formed as “0” (off) and “1” (on) serial data (rectangular wave representing binary data) according to the signal mode of the input signal X1. A control signal X3 is formed based on the transmission data X2, and a drive signal (drive voltage or the like) X4 for the light emitting element 111 is further generated therefrom.

  The modulation frequency of the drive signal X4 at this time is preferably larger than the frame frequency, but it is desirable to adjust the frequency so as not to interfere with each other. Specifically, adjustment may be made so that the period of the modulation frequency and the frame frequency does not become an integral multiple.

  Note that the above configuration is merely an example of a light emission control circuit, and the light emission control circuit only needs to perform modulation control of a light emission mode according to the input signal X1, and is not limited to the above configuration. For example, the input signal X1 may be amplified as it is to drive the light emitting element 111, or the transmission data X1 may be directly applied to the light emitting element 111 and driven.

  When the light emitting element 111 is driven by the drive signal X4, light emitted from the light emitting element 111 (for example, light blinking at high speed) enters the light guide plate 112 and propagates through the light as described above. A part of this light is detected by the photodetector 116 although it is emitted from the emission surface 112b. Since the detection signal Y1 of the photodetector 116 has undergone modulation corresponding to the control signal X3, a demodulation signal Y2 is formed based on the detection signal Y1, and the transmission data is generated based on the demodulation signal Y2. Reception data Y3 corresponding to X2 can be generated. In the illustrated example, the receiving circuit 110Y extracts a modulation component from the detection signal Y1 to form a demodulated signal Y2, and forms received data Y3 corresponding to the transmission data X2 based on the demodulated signal Y2. Data generation means 110E for generating data, and output signal formation means 110F for forming an output signal corresponding to a transfer destination circuit or the like based on the received data Y3.

  Note that this configuration is only an example of a receiving circuit, and the receiving circuit is only required to be able to obtain an output corresponding to the input signal based on the detection signal of the photodetector 116, and is not limited to the above configuration. It is not something. For example, the demodulated signal Y2 and the received data Y3 may be output as output signals as they are.

  In the example of the usage mode of FIG. 1, the drive circuit 127 of the electro-optical panel 120 is controlled based on the detection signal of the photodetector 116. In this case, since the control signal of the drive circuit 127 can be transferred to the drive circuit 127 by optical transmission, even if the control signal has a higher frequency due to high definition of the electro-optical panel 120, generation of radiation noise is generated. Can be suppressed, and no countermeasures are required.

  According to the embodiment described above, since the light emitting element 111 used as the light source of the illumination device 110 is used as the light source for data transfer, it is not necessary to newly provide a light emitting element for data transmission, and the number of parts can be reduced. Thus, the manufacturing cost can be reduced and the size can be reduced. In particular, since the light guided by the light guide plate 112 of the illumination device 110 is directly detected by the photodetector 116, there is no need to newly form a light guide for data transmission. This is more convenient for cost reduction and miniaturization.

  In addition, by performing data transfer by light using the light emitting element 111 and the photodetector 116, the number of wirings and the wiring length can be reduced, so that reliability is improved, unnecessary radiation is reduced, or radiation noise is reduced. Reduction can be achieved.

  Furthermore, since a non-contact transmission path is configured at least in part by using optical transmission type data transfer, the number of electrical connection points is also reduced, so that high reliability can be easily ensured. it can. In particular, since the light emitting element 111 and the photodetector 116 are arranged on the opposite sides of the light guide plate 112, it is sufficient to prevent downsizing of the apparatus without additional light guide members. Since an optical transmission line with a short distance can be secured, the effect of reducing unnecessary radiation or the effect of reducing radiation noise can be enhanced by effectively using the length of the optical transmission line.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIG. In this 2nd Embodiment, the same code | symbol is attached | subjected to the part similar to the said 1st Embodiment, and those description is abbreviate | omitted. FIG. 3 is a schematic configuration diagram showing the overall configuration of the illumination device 110 ′.

  This embodiment is the same as the first embodiment in that the light emission control circuit 110X ′ and the reception circuit 110Y ′ are provided, but the functions of the light emission control circuit 110X ′ and the reception circuit 110Y ′ are the first embodiment. Different from that of form.

  In the light emission control circuit 110X ′ of the present embodiment, control signals X3r, X3g, and X3b in a plurality of wavelength regions are formed based on the input signal X1, and light emission that emits light in a plurality of wavelength regions by these control signals, respectively. Light emission drive means 110Cr, 110Cg, 110Cb for driving the elements 111R, 111G, 111B are controlled.

  As a specific configuration of the light emission control circuit 110X ′, for example, the light emission control circuit 110X ′ includes the data forming unit 110A similar to the first embodiment that converts the transmission data X2 based on the input signal X1, but unlike the first embodiment, Control signal forming means 110B ′ for converting the transmission data X2 into control signals X3r, X3g, and X3b corresponding to a plurality of wavelength ranges in parallel is provided. These control signals X3r, X3g, and X3b are signals for transmitting the transmission data X2 in parallel by optical transmission. The light emission drive means 110Cr, 110Cg, and 110Cb receive the control signals X3r, X3g, and X3b, respectively, and output the drive signals X4r, X4g, and X4b, respectively, and each of the light emitting elements 111R, 111G, and 111B has a predetermined light emission mode. Can be driven independently.

  The plurality of wavelength ranges need only be different from each other so that transfer data can be identified independently of each other, and any wavelength range can be used. For example, it may be a plurality of wavelength regions separated from each other, or may be a plurality of wavelength regions partially overlapping each other. In the present embodiment, the light emitting element 111R emits red light, the light emitting element 111G emits green light, and the light emitting element 111B emits blue light. As the illumination device 110 ′, illumination light having a predetermined wavelength distribution (for example, white) is formed by synthesizing all the light from the light emitting elements 111R, 111G, and 111B. As described above, when the light of R, G, and B colors is combined into white light, the white point may be shifted depending on the degree of modulation of the data of each color. It is desirable to adjust the light emission luminance and pulse width of each light emitting element according to the ratio of on and off so that the white point does not shift.

  The light emitting elements 111R, 111G, and 111B have different emission wavelength ranges, but a light emitting element that integrally includes a light emitting portion that emits a plurality of different emission wavelength ranges may be used. In any case, it is only necessary that the light emission mode can be controlled for each of a plurality of wavelength ranges as a result.

  The light emitted from the light emitting elements 111R, 111G, and 111B propagates through the light guide plate 112 and is then detected by the photodetector 116 ′. At this time, the photodetector 116 ′ is configured to detect the amount of received light for each of the plurality of wavelength ranges. For example, one having a plurality of different light detection units capable of separately detecting a plurality of wavelength regions, or a single light detection unit, but a wavelength region to be detected by controlling the light detection unit It is configured to be able to change (or scan) temporarily. Furthermore, although different from the illustrated example, a plurality of photodetectors for separately detecting a plurality of wavelength ranges may be provided.

  It is most preferable that the plurality of light detection units have detection sensitivities at the peak positions of the wavelength distribution of the plurality of light emitting elements (light emitting units), but the light emission modes in the plurality of wavelength regions can be distinguished from each other. As long as it is configured in this way, it is not limited to such a configuration.

  The detection signals Y1r, Y1g, Y1b of the photodetector 116 ′ are processed in parallel in at least a part of the processing steps by the receiving circuit 110Y ′, and finally an output signal Y4 is output. Specifically, each of the detection signals Y1r, Y1g, Y1b is processed in parallel in the signal demodulation means 110Dr, 110Dg, 110Db to form demodulated signals Y2r, Y2g, Y2b. Further, the data generation means 110E ′ forms the reception data Y3 based on the demodulated signals Y2r, Y2g, Y2b, and finally the output signal formation means 110F generates the output signal Y4.

  Note that, depending on the configuration of the output destination, the reception data Y3 and the output signal Y4 may be output in parallel for each of a plurality of wavelength ranges. For example, when transferring multiple signals that are input / output separately such as video data and control signal, video data and audio data, etc., output from the input signal using light of different wavelength range It is conceivable to process the signals separately in parallel.

  In this embodiment, since optical transmission can be performed in parallel in a plurality of wavelength ranges, high-speed data transfer / data processing by parallel data processing becomes possible. In the present embodiment, the data for three channels is transferred in the R, G, and B wavelength regions. However, if the emission color of the light emitting element and the light receiving sensitivity of the photodetector correspond to each other, It goes without saying that wavelength regions may be used, and the number of wavelength regions may be increased to increase the number of channels.

  In this embodiment, in addition to the effects of the first embodiment, parallel processing by optical transmission is possible, so that multi-channel data transfer can be performed at high speed. In particular, since data transfer is performed in parallel using a plurality of wavelength regions, the separation and detection of light is easy, and the number of channels can be easily increased.

[Third Embodiment]
Next, a third embodiment of the lighting device according to the present invention will be described with reference to FIG. In this embodiment, since the part which is not illustrated can employ | adopt the structure of the said 1st Embodiment or 2nd Embodiment, those description is abbreviate | omitted. FIG. 4 is a schematic plan view showing a planar structure of the illumination device in the present embodiment.

  In this embodiment, each component of the lighting device, for example, the light emitting element 111 and the light guide plate 112 are disposed and positioned inside a case 117 made of synthetic resin or the like. In addition, an opening 117a is formed in a part of the case 117 facing the light guide plate 112, and the photodetector 116 is disposed to face the surface of the light guide plate 112 through the opening 117a. Here, the photodetector 116 is preferably disposed to face a surface other than the light emitting surface 112b, for example, an end surface 112c on the opposite side of the light incident surface 112a as shown.

  Note that the light detector 116 is preferably fixed to the lighting device by a method such as fitting to the case 117. In particular, if the photodetector 116 is fitted and fixed to the opening 117a of the case 117, the photodetector 116 can be fixed to the illumination device without increasing the number of components.

[Fourth Embodiment]
Next, with reference to FIG. 5, 4th Embodiment of the illuminating device based on this invention is described. Also in this embodiment, since the part which is not illustrated can employ | adopt the structure of the said 1st Embodiment or 2nd Embodiment, those description is abbreviate | omitted. FIG. 5 is a schematic plan view showing a planar structure of the illumination device in the present embodiment.

  In this embodiment, each component of the lighting device, for example, the light emitting element 111 and the light guide plate 112 are disposed and positioned inside a case 118 made of synthetic resin or the like. In addition, an opening 118a is formed in a part of the case 118 facing the light guide plate 112 ′, and the photodetector 116 is disposed to face the surface of the light guide plate 112 through the opening 118a.

  In the present embodiment, the portion facing the opening 118a of the light guide plate 112 ′ is a protruding portion 112x protruding outward, and the photodetector 116 is disposed opposite to the surface of the protruding portion 112x. With this configuration, the position of the photodetector 116 can be set without being restricted by the positions of the light guide plate 112 ′ and the case 118.

  In addition, the formation position and shape of the protrusion 112x are arbitrary, and can be appropriately configured according to the light detection position. In contrast to the above, a recess may be formed in a part of the light guide plate 112 ′, and the photodetector 116 may be disposed in the recess. In this case, the lighting device can be configured more compactly.

[Fifth Embodiment]
Next, a fifth embodiment according to the present invention will be described with reference to FIG. Also in this embodiment, since the part which is not illustrated can employ | adopt the structure of the said 1st Embodiment or 2nd Embodiment, those description is abbreviate | omitted. FIG. 6 is a schematic longitudinal sectional view showing a detailed structure of the lighting device in the present embodiment.

  In the present embodiment, the light guide plate 112 ″ includes an inclined surface portion 112c ″ that is inclined with respect to the light propagation direction (right direction in the drawing) on the surface (end surface) other than the light emitting surface 112b ″. This inclined surface portion 112c. ″ Has the function of refracting and reflecting the light propagating through the light guide plate 112 ″, so that the light detectors 116, 116 ″ are opposed to each other in a direction different from the light propagation direction of the light guide plate 112 ″. It becomes possible to detect light.

  For example, the photodetector 116 indicated by the solid line in the figure is disposed so as to face the inclined surface portion 112c ″ and can detect light that is refracted and emitted to the outside at the inclined surface portion 112c ″. Further, the photodetector 116 ″ indicated by a dotted line in the figure is disposed opposite to the surface of the light guide plate 112 ″ that is diagonally opposed to the inclined surface portion 112c ″ via the inside of the light guide plate 112 ″, and the light guide plate is disposed at the inclined surface portion 112c ″. The light reflected from the inside of 112 ″ and emitted from the surface can be detected.

  The illustrated solid line light detector 116 and the illustrated dotted line light detector 116 ″ correspond to the total reflection angle determined by the inclination angle of the inclined surface portion 112c ″ and the light refractive index of the light guide plate 112 ″, and the like. It can be properly used according to the emission characteristics of 112 ″ internal propagation light.

[Sixth Embodiment]
Next, a sixth embodiment according to the present invention will be described with reference to FIG. Also in this embodiment, since the part which is not illustrated can employ | adopt the structure of the said 1st Embodiment or 2nd Embodiment, those description is abbreviate | omitted. FIG. 7 is a schematic plan view showing a planar structure of the illumination device in the present embodiment.

  In the present embodiment, a first light guide plate 112A and a second light guide plate 112B arranged to face the first light guide plate 112A are provided, and the light emitting elements 111R, 111G, and 111B (integrally capable of independently controlling a plurality of wavelength regions). The light emitted from the first light guide plate 112A is emitted toward the second light guide plate 112B while the light incident on the second light guide plate 112B is transmitted through the first light guide plate 112B. The light is emitted from the emission surface 112Bb.

  The first light guide plate 112A is disposed opposite to the light incident surface (end surface) 112Aa, and the light output surface (side surface) 112Ab of the first light guide plate 112A is disposed opposite to the light incident surface (end surface) 112Ba. Has been. Here, the light emitting surface 112Ab of the first light guide plate 112A extends in the width direction of the light incident surface 112Ba of the second light guide plate 112B, and the light emitted from the light emitting elements 111R, 111G, and 111B is inside the first light guide plate 112A. Is emitted from the light emitting surface 112Ba while propagating in the width direction of the second light guide plate 112B, and this emitted light is configured to be substantially uniformly incident on the entire light incident surface 112Ba of the second light guide plate 112B. Yes. Further, the light incident on the second light guide plate 112B is emitted from the light exit surface 112Bb while propagating.

  In the present embodiment, the photodetector 116 is disposed to face the end surface 112Ac on the opposite side of the light incident surface 112Aa of the first light guide plate 112A. Of the light propagating through the first light guide plate 112A, light that has not been emitted from the light exit surface 112Ab is emitted from the end surface 112Ac and received by the photodetector 116.

  In this way, although the light guide structure itself is slightly complicated, it is possible to further reduce the influence on the illumination light emitted from the light exit surface 112Bb of the second light guide plate 112B while reliably performing light transmission. An effect is obtained.

[Seventh Embodiment]
Next, a seventh embodiment according to the present invention will be described with reference to FIG. Also in this embodiment, since the part which is not illustrated can employ | adopt the structure of the said 1st Embodiment or 2nd Embodiment, those description is abbreviate | omitted. FIG. 8 is a schematic plan view showing a planar structure of the illumination device in the present embodiment.

  In the present embodiment, the light emitting element 111 and the light guide plate 112 are positioned and held inside the case 119. The inner surface of the case 119 is disposed opposite to the end surface of the light guide plate 112 other than the light incident surface 112a, and is configured to reflect the light emitted from the end surface and return it to the inside of the light guide plate 112 again. For example, when the illuminating device emits white illumination light, the case 119 is made of white resin or the like, so that the light can be efficiently reflected and a decrease in the light use efficiency can be prevented.

  The photodetector 116 of the present embodiment is disposed on the light emitting element 111 side with respect to the light guide plate 112, and is disposed to face the surface of the light guide plate 112 on the light emitting element 111 side, that is, the light incident surface 112 a. With this configuration, the light emitted from the light emitting element 111 enters the light guide plate 112 from the light incident surface 112a, and the opposite end surface 112c or the inner surface of the case 119 disposed outside the end surface 112c. The light is reflected, propagates in the light guide plate 112 in the opposite direction again, exits from the light incident surface 112a, and is detected by the photodetector 116.

  The photodetector 116 of the present embodiment is disposed on the light emitting element 111 side of the light guide plate 112, but the above configuration is only an example, and light propagates in an arbitrary direction inside the light guide plate 112. If there is, the light can be detected by disposing the light guide plate 112 so as to face an arbitrary surface portion. In particular, as in the above example, although the amount of light is large or small, when the light propagation direction of the light guide plate 112 is randomly generated by the reflection plate such as the case 119, the position of the photodetector 116 is determined. There are almost no restrictions on. However, if the photodetector 116 is disposed on the light emitting surface 112b of the light guide plate 112, the illumination range by the illumination device is restricted, or the planar size of the illumination device needs to be increased. It is desirable that the light guide plate 112 is disposed to face the surface other than the light exit surface 112b.

[Electronics]
Finally, an example of an electronic device on which the display device 100 including the lighting device of each of the above embodiments is mounted will be described with reference to FIGS.

  FIG. 9 shows a notebook personal computer which is an embodiment of the electronic apparatus according to the present invention. The personal computer 200 includes a main body unit 201 including a plurality of operation buttons 201a and other operation devices 201b, and a display unit 202 connected to the main body unit 201 and including a display screen 202a. In the case of the illustrated example, the main body unit 201 and the display unit 202 are configured to be openable and closable. The above-described display device (liquid crystal display device) 100 is built in the display unit 202, and a desired display image is displayed on the display screen 202a. In this case, a display control circuit for controlling the display device 100 is provided inside the personal computer 200. The display control circuit is configured to send a video signal and other input data and a predetermined control signal to the display device 100 to determine its operation mode.

  FIG. 10 shows a mobile phone which is another embodiment of the electronic apparatus according to the invention. A cellular phone 300 shown here includes an operation unit 301 including a plurality of operation buttons 301a and 301b and a mouthpiece, and a display unit 302 including a display screen 302a and a mouthpiece. The display device 100 is incorporated inside. The display image formed by the display device 100 can be viewed on the display screen 302a of the display unit 302. In this case, a display control circuit for controlling the display device 100 is provided inside the mobile phone 300. The display control circuit is configured to send a video signal and other input data and a predetermined control signal to the display device 100 to determine its operation mode.

  As shown in FIGS. 9 and 10, in an electronic device in which two components are configured to be foldable, data transmission of an optical transmission method is performed from one component to the other component. Can do. If it does in this way, the effect that the number of wiring passed through the hinge part which implement | achieves a folding structure can be reduced is acquired.

  As described above, according to the present invention, data transmission of an optical transmission method can be performed using a light emitting element of a lighting device, but transfer data and communication contents by the optical transmission method are not limited at all. In addition to various display signals used for display driving of the electro-optical panel in the above display device (electro-optical device), not only audio signals used for driving separately arranged speakers, portable information terminals, computer equipment, etc. It can be used to transmit arbitrary information such as various data and control signals.

The schematic block diagram of the display apparatus for showing the utilization aspect of the illuminating device of 1st Embodiment. The schematic structure block diagram which shows the whole structure of the illuminating device of 1st Embodiment. The schematic block diagram which shows the whole structure of the illuminating device of 2nd Embodiment. The schematic plan view which shows the principal part of the illuminating device of 3rd Embodiment. The schematic plan view which shows the principal part of the illuminating device of 4th Embodiment. The schematic longitudinal cross-sectional view which shows the detail of the illuminating device of 5th Embodiment. The schematic plan view which shows the principal part of the illuminating device of 6th Embodiment. The schematic plan view which shows the principal part of the illuminating device of 7th Embodiment. FIG. 6 is a schematic perspective view illustrating a configuration example of an electronic device equipped with a display device. The schematic perspective view which shows the other structural example of the electronic device carrying a display apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Display apparatus, 110 ... Illuminating device, 111 ... Light emitting element, 112 ... Light guide plate, 113 ... Reflecting plate, 116 ... Photo detector, 110X ... Light emission control circuit, 110A ... Transmission data formation means, 110B ... Control signal formation means , 110C ... light emission drive means, 110Y ... reception circuit, 110D ... signal demodulation means, 110E ... data generation means, 110F ... output force signal formation means, 112 ... electro-optical panel

Claims (9)

A light emitting element;
A light guide that guides light emitted from the light emitting element and emits illumination light; and
A light emission control circuit that modulates and controls the light emission mode of the light emitting element based on an input signal;
A photodetector that detects light emitted from the light emitting element and outputs a detection signal;
A receiving circuit that outputs an output signal corresponding to the input signal based on the detection signal of the photodetector;
An illumination device comprising:   The illumination device according to claim 1, wherein the light detector is configured to detect light guided by the light guide.   The light guide has a light incident surface on which light emitted from the light emitting element is incident and a light output surface that emits the illumination light, and the light guide from the light output surface while propagating incident light to the inside. The illumination device according to claim 1, wherein the illumination device emits illumination light.   The lighting device according to claim 3, wherein the photodetector is disposed opposite to a surface of the light guide body other than the light emitting surface.   The light emitting elements each emit light in a plurality of wavelength regions that are independently modulated and controlled, the photodetector independently detects the light amounts of light in the plurality of wavelength regions, and the light emission control circuit The light emission modes of the plurality of wavelength regions emitted from the light emitting elements are modulated and controlled independently in parallel, and the receiving circuit processes the detection signals for the plurality of wavelength regions of the photodetector, respectively. The lighting device according to any one of claims 1 to 4, wherein   A display device comprising: the illumination device according to claim 1; and a display body illuminated by the illumination device.   The display device according to claim 6, wherein the display body is an electro-optical panel driven at a predetermined frame frequency, and a modulation frequency of a light emission mode of the light emitting element is higher than the frame frequency.   The light emitting mode of the light emitting element is input in parallel with the illumination by using a lighting device including a light emitting element and a light guide that guides light emitted from the light emitting element to form illumination light. A data transfer method, wherein data transfer is performed by modulating a signal corresponding to a signal, detecting the modulated light, and outputting an output signal corresponding to the input signal. The light emitting mode of the light emitting element is independently modulated for each of a plurality of wavelength regions, and light detection and processing are performed for each of the plurality of wavelength regions, thereby performing data transfer in parallel in the plurality of wavelength regions. The data transfer method according to claim 8.

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