JP5462055B2 - Information input / output device and electronic device - Google Patents

Description

The present invention relates to information input device and an electronic apparatus capable of performing information input by contact or proximity of an object.

  In recent years, optical information input devices (touch sensors) that detect the position of an object using an optical sensor have been developed. This touch sensor has, for example, a light source for illuminating a nearby object and a panel in which optical sensors are arranged in a matrix, and detects the reflected light from the adjacent object by the optical sensor, thereby detecting the object. Has been made.

  Such an optical touch sensor can be easily mounted on a display device such as a liquid crystal display or an organic EL display. For example, a liquid crystal display generally includes a liquid crystal display panel in which a liquid crystal layer is sealed between a driving substrate having a thin film transistor (TFT) and a counter substrate, and a backlight for illuminating the liquid crystal display panel. ing. When such an optical touch sensor is mounted on such a liquid crystal display, the optical sensor is disposed on the same layer as the TFT on the driving substrate, for example, and image display light from the liquid crystal display panel is used. A nearby object can be illuminated. Therefore, a touch sensor built-in display can be realized without increasing the thickness of the entire apparatus and at low cost.

  However, since the amount of light emitted from the liquid crystal display panel differs for each display image, when the object is illuminated using the image display light as described above, the amount of illumination light on the object changes for each display image, and the optical sensor Variations in the amount of light reaching the surface. In other words, since the amount of illumination light on the object depends on the display image, there is a problem that a sufficient amount of light for detection cannot be obtained and good detection accuracy cannot be ensured.

  Therefore, a method has been proposed in which an infrared LED is disposed as a light source for object detection separately from a light source for image display (for example, a white LED (Light Emitting Diode)) (see, for example, Patent Document 1). In Patent Document 1, a white LED and an infrared LED are provided on the side surface of the light guide plate, and each light is incident on the light guide plate to perform surface light emission. At the time of object detection, by turning on the infrared LED, the object can be illuminated with a sufficient and constant light quantity without depending on the display image.

JP 2008-146165 A

  However, since the LED has low light emission efficiency, a large amount of power is consumed to obtain the amount of illumination light necessary for object detection. In addition, there is a problem that a desired detection signal cannot be obtained due to the influence of external light such as ambient light, and thus good detection accuracy cannot be ensured.

The present invention has been made in view of the above problems, its object is to provide while maintaining excellent detection accuracy, the information input-output device and an electronic apparatus capable of reducing power consumption .

Information Input Output device of the present invention includes a laser device that emits non-visible light, a light emitting diode which emits visible light, a light guide plate to perform a surface emission based on the light emitted from the laser element and the light-emitting diodes, the A laser element and a light emitting diode, comprising: a light source section; and an input / output panel that transmits light emitted from the light source section and has a display element and a light receiving element having a light receiving sensitivity in an oscillation wavelength region of the laser element. Are arranged to face a part of the light guide plate, the surface of the light guide plate facing the laser element has one or a plurality of recesses, and the surface of the light guide plate facing the light emitting diode is flat. Is.

Further, the information input and output apparatus of the present invention includes a laser device that emits non-visible light, a light emitting diode which emits visible light, a light guide plate to perform a surface emission based on the light emitted from the laser element and the light-emitting diodes, the An input / output panel having a display element and a light receiving element having a light receiving sensitivity in an oscillation wavelength region of the laser element. The light emitting diode is embedded in a part of the light plate and is disposed to face the other part of the light guide plate .

Electronic device of the present invention has an information input output device of the present invention.

The information input and output device and an electronic apparatus of the present invention, emitted from the laser element of the light source, the light transmitted through the input and output panel illuminates an object in proximity to the input output panel. Since the light receiving element has light receiving sensitivity in the oscillation wavelength range of the laser element, the light receiving element acquires an object detection signal based on the laser beam.

According to information input and output device and an electronic apparatus of the present invention comprises a laser device light source unit emits invisible light, the light receiving element provided in the input and output panel is light-receiving sensitivity to the oscillation wavelength region of the laser element Therefore, it is possible to detect an object using a laser element. That is, object detection can be performed without using (or driving) a light emitting diode that requires a large amount of power consumption. In addition, by using a laser element, an extremely high output can be obtained as compared with external light, so that the influence of external light can be reduced to a negligible level. Therefore, it is possible to reduce power consumption while ensuring good detection accuracy.

1 is a block diagram illustrating a schematic configuration of an information input / output device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a schematic configuration of an input / output panel and a backlight illustrated in FIG. 1. FIG. 3 is a cross-sectional view illustrating a stacked structure of the photosensor illustrated in FIG. 2. It is a characteristic view showing the relationship between the light reception wavelength and the reflectance in each case where the film thickness of the silicon nitride film shown in FIG. 3 is changed. FIG. 3 is a perspective view illustrating a schematic configuration of the backlight illustrated in FIG. 2. It is a characteristic view showing the relationship between the electric current and output in a laser and LED. It is a characteristic view showing the relationship between the oscillation wavelength (light emission wavelength) and output in a laser and LED. FIG. 5 is a characteristic diagram showing a relationship between a light receiving wavelength and a sensor output in each case where the film thickness of the silicon nitride film shown in FIG. 4 is changed. It is a schematic diagram for demonstrating the optical system used in the case of the characteristic evaluation shown in FIG. It is a perspective view showing schematic structure of the backlight which concerns on a modification. It is a perspective view showing the external appearance of the application example 1 of the information input / output device of this invention. (A) is a perspective view showing the external appearance seen from the front side of the application example 2, (B) is a perspective view showing the external appearance seen from the back side. 12 is a perspective view illustrating an appearance of application example 3. FIG. 14 is a perspective view illustrating an appearance of application example 4. FIG. (A) is a front view of the application example 5 in an open state, (B) is a side view thereof, (C) is a front view in a closed state, (D) is a left side view, and (E) is a right side view, (F) is a top view and (G) is a bottom view.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The description will be given in the following order.

1. Embodiment (example in which a white LED for image display and an infrared laser for object detection are arranged on the light incident surface of a light guide plate)
2. Modified example (example in which laser is embedded in light guide plate by insert molding)
3. Application examples 1-5 (application examples for electronic devices)

<Embodiment>
[Overall Configuration of Information Input / Output Device 1]
FIG. 1 shows a schematic configuration of an information input / output device (information input / output device 1) according to an embodiment of the present invention. FIG. 2 illustrates a cross-sectional configuration of the input / output panel 10 and the backlight 110. The information input / output device 1 is a so-called touch sensor built-in display that inputs information using, for example, a finger or a stylus. The information input / output device 1 includes an input / output panel 10, a display signal processing unit 12, a received light signal processing unit 13, and an image processing unit 14. A backlight 110 (FIG. Not shown). These display signal processing unit 12, received light signal processing unit 13, image processing unit 14 and backlight 110 are each controlled by a control unit (not shown).

(Backlight 110)
The backlight 110 includes, for example, an illumination light source 110A and a light guide plate 110B that performs surface light emission based on light emitted from the illumination light source 110A. The illumination light source 110A includes an LED (Light Emitting Diode) chip and a laser chip, details of which will be described later. Accordingly, in the backlight 110, the LED light and the laser light are respectively incident on the same light guide plate 110A and emitted from the same light emitting surface. The detailed configuration of the backlight 110 will be described later.

(Input / output panel 10)
The input / output panel 10 is a liquid crystal display panel in which a plurality of pixels 11 are arranged in a matrix, and each pixel 11 includes a display element CW and a light receiving element CR. The display element CW is a liquid crystal element that displays an image using illumination light from the backlight 110 (visible light from an LED 110A1 described later). The light receiving element CR is a light receiving element that includes a photo sensor 114B described later, and outputs light received based on illumination light from the backlight 110 (invisible light from a laser 110A2 described later) as an electrical signal. Here, each pixel 11 has one display element CW and one light receiving element CR. However, not all the pixels 11 need to have the light receiving element CR, and the light receiving elements CR are thinned and provided. Also good. Detailed configurations of the input / output panel 10 and the backlight 110 will be described later.

(Display signal processing unit 12)
The display signal processing unit 12 is a circuit that drives the input / output panel 10 so as to perform an image display operation and a light receiving operation based on display data. For example, the display signal holding control unit 40, the display-side scanner 41, and the display signal driver 42. And a light receiving side scanner 43. The display signal holding control unit 40 stores and holds the display signal output from the display signal generating unit 44 in a field memory such as an SRAM (Static Random Access Memory), and also displays the display side scanner 41 and the display signal driver 42. The operation of the light receiving side scanner 43 is also controlled. Specifically, a display timing control signal is output to the display-side scanner 41, and a light-receiving timing control signal is output to the light-receiving side scanner 43. The display signal driver 42 outputs one horizontal signal based on the display signal held in the field memory. The display signal for the line is output. Thereby, the line sequential display operation and the light receiving operation are performed in the input / output panel.

  The display-side scanner 41 has a function of selecting the display element CW to be driven in accordance with the display timing control signal CTL1 output from the display signal holding control unit 40. Specifically, a display selection signal is supplied via a display gate line connected to each pixel 11 of the input / output panel 10 to control the display element selection switch. That is, when a voltage that turns on the display element selection switch of a pixel 11 is applied by the display selection signal, the pixel 11 performs a display operation with a luminance corresponding to the voltage supplied from the display signal driver 42. It is like that.

  The display signal driver 42 has a function of supplying display data to the display element CW to be driven in accordance with a display signal for one horizontal line output from the display signal holding control unit 40. Specifically, a voltage corresponding to display data is supplied to the pixel 11 selected by the display-side scanner 41 through a data supply line connected to each pixel 11 of the input / output panel 10.

  The light receiving side scanner 43 has a function of selecting the light receiving element CR to be driven in accordance with the light receiving timing control signal CTL2 output from the display signal holding control unit 40. Specifically, a light receiving selection signal is supplied via a light receiving gate line connected to each pixel 11 of the input / output panel 10 to control the light receiving element selection switch. That is, similar to the operation of the display-side scanner 41 described above, when a voltage that turns on the light-receiving element selection switch of a certain pixel 11 is applied by the light-receiving selection signal, the light-receiving signal detected from the pixel 11 is received. It is output to the signal receiver 45. The light receiving side scanner 43 outputs a light receiving block control signal CTL3 to the light receiving signal receiver 45 and the light receiving signal holding unit 46, and has a function of controlling the blocks contributing to the light receiving operation. In the present embodiment, the display gate line and the light receiving gate line are separately connected to the respective pixels 11, and the display side scanner 41 and the light receiving side scanner 43 can operate independently of each other. ing.

(Light reception signal processing unit 13)
The light reception signal processing unit 13 takes in a light reception signal from the light reception element CR and performs signal amplification, filter processing, and the like, and includes, for example, a light reception signal receiver 45 and a light reception signal holding unit 46.

  The light receiving signal receiver 45 has a function of acquiring a light receiving signal for one horizontal line output from each light receiving element CR in accordance with the light receiving block control signal CTL3 output from the light receiving side scanner 43. The light reception signal for one horizontal line acquired by the light reception signal receiver 45 is output to the light reception signal holding unit 46.

  The light reception signal holding unit 46 stores and holds the light reception signal output from the light reception signal receiver 45 in a field memory such as an SRAM in accordance with the light reception block control signal CTL3 output from the light reception side scanner 43. . The data of the received light signal stored in the received light signal holding unit 46 is output to the image processing unit 14. The received light signal holding unit 46 may be formed of a storage element other than the memory. For example, the received light signal may be held in the capacitive element as analog data (charge).

(Image processing unit 14)
The image processing unit 14 is a circuit that captures captured image data from the received light signal processing unit 13 and performs predetermined image processing to detect information (object information) on the position of the object. Specifically, the image processing unit 14 performs processing such as binarization, isolated point removal, and labeling on the captured image data, and calculates the position coordinates and area of the proximity object.

  Hereinafter, detailed configurations of the input / output panel 10 and the backlight 110 will be described.

[Detailed Configuration of Input / Output Panel 10]
As shown in FIG. 2, the input / output panel 10 has a liquid crystal layer 117 sandwiched between the driving substrate 113 and the counter substrate 120, and a polarizing plate 112 is disposed outside the driving substrate 113 and the counter substrate 120. And a polarizing plate 121 are bonded together. A planarizing film 115 is formed on the driving substrate 113 so as to cover the surface of the driving substrate 113, and the pixel electrode 116 is disposed on the planarizing film 115. On the liquid crystal layer 15 side of the counter substrate 120, a counter electrode 118 is disposed over almost the entire effective display area. Between the counter electrode 118 and the counter substrate 120, for example, red (R), green (G ), A color filter layer 119 including filters of the three primary colors of blue (B) is provided. The pixel electrode 116 and the counter electrode 118 are made of a transparent conductive film such as ITO (indium tin oxide), for example, and an alignment film (not shown) is formed on each of these surfaces (surface on the liquid crystal layer 117 side). The liquid crystal layer 117 includes liquid crystal in various display modes such as a VA (Vertical Alignment) mode, a TN (Twisted Nematic) mode, and an IPS (In-Plane Switching) mode. The polarizing plate 112 and the polarizing plate 121 are arranged in a crossed Nicols state, for example, so that light from the backlight 110 is blocked when no voltage is applied (off state) and transmitted when the voltage is applied (on state). It has become. The cover 122 protects the surface of the input / output panel 10 and serves as a contact surface for an object such as a finger.

  The drive substrate 113 is, for example, a drive circuit for driving the pixels 11 on a glass substrate, for example, the display signal processing unit 12 and the light reception signal processing unit 13 described above. These drive circuits are connected to the respective pixel electrodes 116 through wiring such as gate lines and TFTs (thin film transistors) (both not shown). On the driving substrate 113, photosensors 114 as light receiving elements CR are arranged in a matrix for each pixel 11, for example.

(Photo sensor 114)
FIG. 3 illustrates an example of a layer structure of the photosensor 114. In the photosensor 114, a dielectric film 1145 having a low refractive index is sandwiched between a polycrystalline silicon (polysilicon) layer 1143 having a high refractive index and an amorphous silicon (amorphous silicon) layer 1146 having a high refractive index. It is a thing. A reflective film 1144 made of, for example, molybdenum is formed between the polycrystalline silicon layer 1143 and the dielectric film 1145, and a light absorption layer 1147 made of, for example, SiO is formed on the light incident side of the amorphous silicon layer 1146. Is formed. For example, insulating films 1141 and 1142 (for example, SiO ₂ and SiN) are stacked on the back surface of the polycrystalline silicon layer 1143 (surface opposite to the reflective film 1144) to ensure insulation with the transistor, for example. Yes.

  In the photosensor 114, a resonant structure (cavity structure) having an optical confinement effect is realized by the laminated structure as described above. That is, in the photosensor 114, the incident light L is repeatedly reflected and interfered between the interface C1 between the dielectric film 1145 and the amorphous silicon layer 1146 and the interface C2 between the dielectric film 1145 and the reflective film 1144. As a result, light is confined in the dielectric film 1145. Due to this light confinement effect, the light receiving sensitivity of the photosensor 114 can be increased. In the present embodiment, the light receiving sensitivity of the photosensor 114 is increased in the oscillation wavelength region of a laser 110A2 described later.

  Here, FIG. 4 shows the wavelength (nm) of the incident light L when the thickness of the dielectric film 1145 made of silicon nitride (SiN: refractive index 1.52) is changed in increments of 25 nm in the range of 150 nm to 275 nm. The relationship of the reflectance (%) with respect to is shown. At this time, the thickness of the polycrystalline silicon layer 1143 was 43 nm (refractive index: 3.67), and the thickness of the amorphous silicon layer 1146 was 53 nm (refractive index: 4.0). As shown in FIG. 4, it can be seen that the light receiving wavelength region changes due to the change in the thickness of the dielectric film 1145. That is, the light reception wavelength range in the photosensor 114 depends on the film thickness of the dielectric film 1145. Therefore, in the present embodiment, for example, when the oscillation wavelength region of the laser 110A2 is in the vicinity of 850 nm, the film thickness (200 nm in this case) of the dielectric film 1145 exhibiting the highest reflectance with respect to the wavelength 850 nm. Selected. As described above, the photosensor 114 has a resonance structure having the above-described optical confinement effect, and by optimizing the film thickness of the dielectric film 1145, the light receiving sensitivity of the photosensor 114 can be set to a desired wavelength range (laser 110A2). In the oscillation wavelength region).

  As described above, it is desirable that the photosensor 114 has higher light receiving sensitivity (than other wavelength regions) in the oscillation wavelength region (for example, near 850 nm) of the laser 110A2. This is because the influence of light in a wavelength region other than the oscillation wavelength region of the laser 110A2, such as external light, can be reduced.

  The optical functional layer 111 is inserted between the light incident side of the input / output panel 10 as described above, that is, between the input / output panel 10 and the backlight 110. The optical functional layer 111 is formed by laminating various optical sheets such as a diffusion sheet, a diffusion plate, and a prism sheet. With such an optical function layer 111, light emitted from the backlight 110 can be extracted to the input / output panel 10 side as uniform and uniform illumination light.

[Detailed Configuration of Backlight 110]
5A and 5B show the configuration of the backlight 110, where FIG. 5A shows the overall configuration, and FIG. 5B shows an enlarged view of the vicinity of the facing surface between the light guide plate 110B and the laser 110A2. The backlight 110, for example, causes the incident light from the illumination light source 110A provided on the side surface of the light guide plate 110B to be totally reflected inside, and then emits the illumination light L ₀ from the upper surface (surface emission), for example.

The light guide plate 110B is a flat plate-like member having a rectangular planar shape, for example, and made of a transparent resin material such as polycarbonate or acrylic. An illumination light source 110A is provided on the side surface of the light guide plate 110B, and the upper surface is a light emitting surface. A plurality of grooves are formed on the bottom surface of the light guide plate 110B opposite to the light emitting surface (groove pattern 110B1), and the groove pattern 110B1 defines the total reflection condition of light propagating through the light guide plate 110B by total reflection. It is broken and emitted as illumination light L ₀ from the upper surface.

  The illumination light source 110A includes, for example, an LED 110A1 and a laser 110A2. The LED 110A1 is an LED chip that emits visible light, and is a light source for image display. This LED 110A1 is, for example, a white LED. As the white LED, for example, a combination of LED chips of three colors of a red LED, a green LED, and a blue LED and realizing a pseudo white color by mixing these colors can be cited. Alternatively, for example, a YAG phosphor may be applied to the package portion of the blue LED, and a pseudo white color may be realized by color mixture generated by color conversion of blue light.

  The laser 110A2 is a laser diode chip that emits invisible light, and is a light source for object detection. The laser 110A2 is, for example, an infrared laser that emits light having a wavelength of 780 nm to 1000 nm, specifically, 850 nm. Examples of such a laser 110A2 include AlGaAs, InGaAs, InP, and GaInAsNP semiconductor lasers.

  These LEDs 110A1 and laser 110A2 are arranged such that their emission surfaces (emission surfaces) face the side surfaces of the light guide plate 110B. However, in the present embodiment, prism processing is performed only on the surface (light incident surface) facing the laser 110A2 of the light guide plate 110B so as to increase the radiation angle of incident light.

  For example, as shown in FIG. 5B, a plurality of (here, three) recesses 110B2 are formed on the surface of the light guide plate 110B facing the laser 110A2. Recess 110B2 has, for example, a surface shape curved in a semi-cylindrical shape. The emission angle of the laser beam is generally as narrow as about 20 ° to 30 °. However, by providing such a recess 110B2, the laser beam can be refracted and incident on the light guide plate 110B with a large emission angle. Thereby, since light rays are dispersed in a wide range in the light guide plate 110B, uniform surface light emission is easily obtained. The region between the light guide plate 110B and the laser 110A2 may be a gap (air) or may be filled with an adhesive layer. That is, the laser 110A2 may be placed only on the side surface side of the light guide plate 110B, or may be in close contact with the side surface by, for example, an adhesive layer. The surface shape of the recess 110B2 is not limited to the semi-cylindrical curved surface as described above as long as the radiation angle of the laser beam can be enlarged. For example, a hemispherical shape or a triangular prism shape may be used.

  On the other hand, the surface (light incident surface) facing the LED 110A1 of the light guide plate 110B is not subjected to such processing and is a flat surface. Since LED light generally has a half-value angle of about 120 °, the LED light easily spreads in all directions. For this reason, it is desirable that the LED 110A1 is provided in close contact with the light guide plate 110B so that the LED light is reliably incident into the light guide plate 110B.

  Such a backlight 110 can be formed as follows, for example. That is, first, after forming a light guide plate 110B by molding a resin material into a flat plate shape by an injection molding method, for example, a groove pattern 110B1 is formed on the bottom surface of the light guide plate 110B, and a part of the side surface (a surface facing the laser 110A2) Each of the recesses 110B2 is formed by cutting, for example. The laser 110A2 is disposed to face the concave portion 110B2 on the side surface of the light guide plate 110B formed in this manner, and the LED 110A1 is disposed to face the flat surface of the side surface. If necessary, the light guide plate 110B and the LEDs 110A1, and the light guide plate 110B and the laser 110A2 are bonded to each other.

[Operation and effect of information input / output device 1]
(Display operation)
In the information input / output device 1, when display data is input from the outside to the display signal processing unit 12, the display signal processing unit 12 drives the input / output panel 10 based on the display data. As a result, the input / output panel 10 performs image display by the display element CW using the illumination light from the backlight 110. Here, the backlight 110 includes an LED 110A1 that emits visible light and a laser 110A2 that emits invisible light. When an image is displayed, the LED 110A1 is turned on to illuminate the input / output panel 10.

(Detection operation)
On the other hand, when the display signal processing unit 12 drives the input / output panel 10 to receive light, the input / output panel 10 receives light by the light receiving element CR (photosensor 114) using the illumination light from the backlight 110 (detection operation). ) Is performed. However, during this light receiving operation, the laser 110A2 is turned on in the backlight 110. At this time, when an object such as a finger is in contact with or close to the input screen of the input / output panel 10 (the surface of the cover 122), the object is illuminated by illumination light from the backlight 110 (illumination light based on laser light). Is done. Since the photosensor 114 has light reception sensitivity in the oscillation wavelength region of the laser 110A2, a light reception signal of an object based on the laser light can be obtained. Thus, in the present embodiment, a detection operation using the laser 110A2 is possible.

  Here, FIG. 6 shows the relationship between the current (mA) and the output (μW) of the infrared laser and infrared LED, respectively. As described above, the infrared laser can obtain a larger amount of light (output) with less current than the infrared LED. For example, when each is driven at 10 mA, the infrared laser can suppress the required power to about 1/2 to 1/3 or less of the infrared LED.

By the way, the oscillation wavelength range of the laser is narrower than the emission wavelength range of the LED. For example, FIG. 7 shows the relationship between the wavelength (nm) and the output (μW / cm ² / nm) in a laser and LED each having an oscillation (emission) peak near 850 nm. However, the drive current was 5 mA. As described above, the output of the laser is concentrated in the vicinity of 850 nm, whereas the output of the LED is distributed in a relatively wide range of about 800 nm to 900 nm. In this embodiment, since the photosensor 114 has a resonance structure having a light confinement effect, as described above, the light receiving sensitivity in the oscillation wavelength region of the laser 110A2, for example, around 850 nm can be increased. For this reason, for example, the above laser beam having an oscillation peak at 850 nm can be efficiently received. Therefore, it is possible to obtain a light amount necessary for detection with smaller electric power. Further, since the laser light has an overwhelmingly higher output than ambient light such as external light, it is possible to reduce the laser light so that the influence of external light can be substantially ignored.

  In addition, since the laser 110A2 can obtain a larger output than the LED, a sufficient amount of detected light can be ensured without always turning on the laser 110A2 when detecting an object. That is, in the backlight 110, the laser 110 </ b> A <b> 2 may be intermittently driven in time by alternately performing a lighting operation and a light-off operation with a predetermined duty. By setting the lighting time to a shorter time than the light-off time, not only can power consumption be reduced and the influence of external light can be reduced, but also the generation of pseudo signals can be suppressed, for example, when detecting fast-moving objects. can do. This is because the light reception timing is thinned out in time, so that it becomes easy to capture a certain moment of an object that is continuously moving and it is easy to recognize it as a stationary object.

  FIG. 8 shows a prototype of the input / output panel 10 as described above and the output from the photosensor 114 measured. In the measurement, as shown in FIG. 9, the input / output panel 10 was irradiated with light using a Xe lamp, and the wavelength was changed. Further, as the photosensor 114, the film thickness B of the dielectric film 1145 (SiN) in the resonance structure shown in FIG. 3 was set to 200 nm, 225 nm, 250 nm, and 275 nm, respectively. Also in this case, the sensor output (light receiving sensitivity) was highest in the vicinity of 850 nm in an example in which the film thickness B of SiN was 200 nm. However, “REF” in FIG. 8 represents an output from a general photosensor having no resonance structure (that is, a structure without the dielectric film 1145 and the amorphous silicon layer 1146).

  The received light signal processing unit 13 performs processing such as amplification on the received light signal thus obtained, generates a captured image, and outputs the captured image to the image processing unit 14. The image processing unit 14 performs binarization processing, isolated point removal processing, labeling processing, and the like on the captured image input from the light reception signal processing unit 13 to obtain object information such as the position coordinates and area of the object. To do. As described above, the input / output panel 10 performs image display and object detection.

  As described above, in this embodiment, the backlight 110 includes the laser 110A2 that emits invisible light (for example, infrared light), and the photosensor 114 provided in the input / output panel 10 includes the oscillation wavelength of the laser 110A2. Since the region has light receiving sensitivity, it is possible to detect an object using the laser 110A2. That is, object detection can be performed without using (or driving) an LED that requires a large amount of power consumption. Further, since the laser light has an overwhelmingly higher output than ambient light such as external light, it is possible to reduce the laser light so that the influence of external light can be substantially ignored. Therefore, it is possible to reduce power consumption while ensuring good detection accuracy.

<Modification>
Hereinafter, modifications of the backlight 110 according to the above embodiment will be described. In addition, the same code | symbol is attached | subjected about the component similar to the said embodiment, and description is abbreviate | omitted suitably.

10A and 10B show a configuration of a backlight (backlight 130) according to a modified example. FIG. 10A is an overall configuration, and FIG. 10B is an enlarged view of the vicinity of the facing surface between the light guide plate 110B and the illumination light source 110A. Is. The backlight 130 is provided with an illumination light source 110A including an LED 110A1 and a laser 110A2 on the side surface of the light guide plate 110B, as in the backlight 110 of the above embodiment, and the LED light and the laser light are guided in the same way. The light enters the optical plate 110B and is emitted as illumination light L ₀ from the upper surface.

  However, in this modification, the laser 110A2 is embedded in a part of the side surface of the light guide plate 110B. For example, as shown in FIG. 5B, a part of the side surface of the light guide plate 110B protrudes (protrusion 110B3), and a laser 110A2 is provided in the protrusion 110B3. On the other hand, the LED 110A1 is disposed, for example, facing a part of the side surface of the light guide plate 110B, and is in close contact with the light guide plate 110B and the adhesive layer 131.

  Such a backlight 130 can be formed as follows, for example. That is, first, when the light guide plate 110B is formed by molding a resin material into a flat plate shape by, for example, injection molding, the laser 110A2 is embedded by the following insert molding method. For example, in an injection molding machine, a molten resin material is poured into a cavity (mold) and then cooled and solidified to form a flat plate. Before the resin material is poured into the cavity, the laser 110A2 is placed in the cavity in advance. Insert it in. The light guide plate 110B in which the laser 110A2 is embedded can be formed by pouring and solidifying the resin material after the laser 110A2 is inserted. Thereafter, the LEDs 110A1 are arranged facing each other on the flat side surface of the light guide plate 110B, and the light guide plate 110B and the LEDs 110A1 are adhered to each other by the adhesive layer 131.

  Also in the backlight 130 of this modification, the LED 110A1 is turned on when an image is displayed, and the laser 110A2 is turned on when an object is detected, thereby exhibiting the same function as the backlight 110 of the above embodiment. However, in this modification, the laser 110A2 is embedded in a part of the light guide plate 110B, and no interface exists between the laser 110A2 and the light guide plate 110B. Therefore, optical loss due to the interface can be eliminated. Further, as described above, since the emission angle of the laser light is as narrow as 20 ° to 30 °, unlike the LED light described later, the light does not escape outside the light guide plate even if there is no interface. Further, by embedding the laser 110A2 in the light guide plate 110B by insert molding, the light guide plate 110B can be collectively formed and the laser 110A2 can be attached in a batch, thereby simplifying the manufacturing process.

  On the other hand, the LED 110A1 is disposed to face the side surface of the light guide plate 110B, and there is an interface with the light guide plate 110B. As described above, since LED light has a wide radiation angle, if it is buried in the light guide plate 110B to eliminate the interface, the LED light is emitted from the LED 110A1 in all directions in the light guide plate 110B. It becomes. Therefore, only a part of the light emitted from the LED 110A1 satisfies the total reflection condition, and most of the light escapes from the light guide plate 110B. Therefore, if there is an interface between the LED 110A1 and the light guide plate 110B, the light once incident on the light guide plate through this interface satisfies the total reflection condition, and therefore there is no loss of light after the incidence. However, in the stage before being incident on the light guide plate 110B, light loss is likely to occur due to the spread of the LED light. Therefore, it is desirable that the LED 110A1 and the light guide plate 110B be in close contact with the adhesive layer 131 or the like.

<Application example>
Next, application examples of the information input / output device described in the above embodiment will be described with reference to FIGS. The information input / output device can be applied to electronic devices in various fields such as television devices, digital cameras, notebook personal computers, portable terminal devices such as mobile phones, and video cameras. In other words, the information input / output device can be applied to electronic devices in various fields that display an externally input video signal or an internally generated video signal as an image or video.

(Application example 1)
FIG. 11 shows the appearance of a television device. This television apparatus has, for example, a video display screen unit 510 including a front panel 511 and a filter glass 512, and this video display screen unit 510 corresponds to the information input / output device according to the above embodiment.

(Application example 2)
FIG. 12 shows the appearance of a digital camera. The digital camera includes, for example, a flash light emitting unit 521, a display unit 522, a menu switch 523, and a shutter button 524, and the display unit 522 corresponds to the information input / output device according to the above embodiment. .

(Application example 3)
FIG. 13 shows the appearance of a notebook personal computer. The notebook personal computer has, for example, a main body 531, a keyboard 532 for inputting characters and the like, and a display unit 533 for displaying an image, and the display unit 533 includes the information input unit according to the above embodiment. It corresponds to an output device.

(Application example 4)
FIG. 14 shows the appearance of the video camera. This video camera includes, for example, a main body 541, a subject shooting lens 542 provided on the front side surface of the main body 541, a start / stop switch 543 at the time of shooting, and a display 544. The display unit 544 corresponds to the information input / output device according to the above embodiment.

(Application example 5)
FIG. 15 shows the appearance of a mobile phone. For example, the mobile phone is obtained by connecting an upper housing 710 and a lower housing 720 with a connecting portion (hinge portion) 730, and includes a display 740, a sub-display 750, a picture light 760, and a camera 770. Yes. The display 740 or the sub-display 750 corresponds to the information input / output device according to the above embodiment.

  Although the present invention has been described with the embodiment, the modification, and the application example, the present invention is not limited to the embodiment and the like, and various modifications are possible. For example, in the above-described embodiment and the like, the example in which one laser and one LED are disposed on the side surface of the light guide plate as the backlight is described as an example, but the configuration of the backlight is not limited thereto. For example, a plurality of lasers and LEDs may be arranged, or these may be arranged on different side surfaces of the light guide plate.

  In the above-described embodiments, the information input / output device including the input / output panel in which the display function and the detection function (light receiving function) are integrated has been described as an example. However, the present invention is not limited to this. For example, the present invention can be applied to an information input / output device in which a touch sensor is externally attached to a display device. In addition, the present invention does not necessarily have a display function (display element). That is, the present invention can be applied to an information input device (imaging device) including an input panel having only a detection function (light receiving element). Further, such an input panel and an output panel (display panel) having a display function may be provided separately.

  DESCRIPTION OF SYMBOLS 1 ... Information input / output device, 10 ... Input / output panel, 11 ... Pixel, CW ... Display element, CR ... Light receiving element, 12 ... Display signal processing part, 13 ... Light receiving signal processing part, 14 ... Image processing part, 110 ... Back 110A1 ... LED, 110A2 ... laser, 110B ... light guide plate, 111 ... optical functional layer, 112,121 ... polarizing plate, 113 ... drive substrate, 114 ... photosensor, 115 ... flattening film, 116 ... Pixel electrode, 117 ... Liquid crystal layer, 118 ... Counter electrode, 119 ... Color filter layer, 120 ... Counter substrate.

Claims (9)

A light source unit having a laser element that emits invisible light, a light emitting diode that emits visible light, and a light guide plate that performs surface emission based on the light emitted from the laser element and the light emitting diode;
An input / output panel that transmits light emitted from the light source unit and includes a display element and a light receiving element having light receiving sensitivity in an oscillation wavelength region of the laser element;
With
Each of the laser element and the light emitting diode is disposed to face a part of the light guide plate,
The surface of the light guide plate facing the laser element has one or a plurality of dents,
The surface of the light guide plate facing the light emitting diode is flat.
Information input / output device. A light source unit having a laser element that emits invisible light, a light emitting diode that emits visible light, and a light guide plate that performs surface emission based on the light emitted from the laser element and the light emitting diode;
An input / output panel that transmits light emitted from the light source unit and includes a display element and a light receiving element having light receiving sensitivity in an oscillation wavelength region of the laser element;
With
The laser element is embedded in a part of the light guide plate,
The light emitting diode is disposed to face another part of the light guide plate.
Information input / output device. The laser element is an infrared laser;
The light emitting diode is a white light emitting diode.
The information input / output device according to claim 1. The peak of the oscillation wavelength of the laser element is in the vicinity of 850 nm.
The information input / output device according to claim 3. The light receiving element has a resonance structure having a light confinement effect.
The information input / output device according to any one of claims 1 to 4. The light receiving element, as the resonance structure,
A dielectric film having a low refractive index;
Each of them has a high refractive index, and a polycrystalline silicon film and an amorphous silicon film provided with the dielectric film interposed therebetween,
A reflective film provided between the polycrystalline silicon film and the dielectric film;
including
The information input / output device according to claim 5. A control unit for controlling the light emission operation of the light source unit;
The control unit intermittently drives the laser element in time.
The information input / output device according to claim 1. A light source unit having a laser element that emits invisible light, a light emitting diode that emits visible light, and a light guide plate that performs surface emission based on the light emitted from the laser element and the light emitting diode;
An input / output panel that transmits light emitted from the light source unit and includes a display element and a light receiving element having light receiving sensitivity in an oscillation wavelength region of the laser element;
With
Each of the laser element and the light emitting diode is disposed to face a part of the light guide plate,
The surface of the light guide plate facing the laser element has one or a plurality of dents,
The surface of the light guide plate facing the light emitting diode is flat.
An electronic device equipped with an information input / output device. A light source unit having a laser element that emits invisible light, a light emitting diode that emits visible light, and a light guide plate that performs surface emission based on the light emitted from the laser element and the light emitting diode;
An input / output panel that transmits light emitted from the light source unit and includes a display element and a light receiving element having light receiving sensitivity in an oscillation wavelength region of the laser element;
With
The laser element is embedded in a part of the light guide plate,
The light emitting diode is disposed to face another part of the light guide plate.
An electronic device equipped with an information input / output device.

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