JP2007206449A - Light-emitting device with sensor function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a light-emitting device function as a sensor, while exhibiting the display capability of a display. <P>SOLUTION: The light emitting device has a light reception detecting circuit 40 which generates a light reception signal with a photoelectromotive force, when a semiconductor light-emitting element receives light to generate the photoelectromotive force. An illumination control circuit 30 has a sensor input 26 for inputting a light reception signal of the semiconductor light-emitting element. The illumination control circuit 30 can switch an illumination mode, wherein the semiconductor light emitting element is turned on and a sensor mode, wherein the semiconductor light-emitting element is turned off and function as a sensor is made effective in a time-division manner. In the illumination mode, a turn-on circuit 20 is driven to supply electric power to the semiconductor light-emitting element, which is made to illuminate. While in the sensor mode, the turn-on circuit 20 stops supplying the electric power to the semiconductor light-emitting element; and when the light reception detecting circuit 40 generates the light reception signal generated as the semiconductor light-emitting element receives light and generates electromotive force, that is detected through the sensor input 26, to detect the light reception state being entered. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light emitting device with a sensor function in which a sensor function for detecting light or the like is added to a light emitting device composed of semiconductor light emitting elements such as LEDs.

  A light-emitting device using a semiconductor element as a light-emitting element emits light with a small color, high power efficiency, and vivid colors. In addition, a light emitting element which is a semiconductor element does not have a concern about a broken ball. Further, it has excellent initial driving characteristics and is strong against vibration and repeated on / off lighting. Because of such excellent characteristics, light-emitting devices using semiconductor light-emitting elements such as light-emitting diodes (LEDs) and laser diodes (LDs) are used as various light sources. Applications include general lighting, displays, liquid crystal backlights, and the like. For example, a dot matrix LED display in which LEDs are arranged in a dot matrix is used for a full color display, an electric bulletin board, and the like.

  Contrary to the light emitting element, a light receiving element for detecting light has been developed, and it is utilized that an optical sensor is constituted by a photodiode (PD) or the like. The light receiving element detects incident light as a photocurrent, detects light and detects its intensity.

  Conventionally, in order to give such a display a sensor function, it has been necessary to arrange a light receiving element such as a PD in addition to a light emitting element such as an LED. In order to add a sensor function to the entire surface of the display, it is necessary to arrange PDs in a matrix as well as LEDs. However, when the LED and the PD are mounted at the same time, there is a problem that the display becomes larger because the mounting area increases. In addition to the LED, wiring for driving the PD is also required, which complicates the configuration and increases the manufacturing cost.

On the other hand, both LED and PD are basically semiconductors having a pn junction. For this reason, when light is irradiated to the pn junction of the LED, a photovoltaic force is generated in a direction in which the pn junction is biased in the forward direction. Utilizing this property, a line sensor device using an LED as a light receiving element as well as a light emitting element has been developed (see Patent Document 1). As a result, space efficiency is good and cost reduction can be realized. However, the line sensor has a drawback that the information that can be displayed is limited and the application is limited. In the above technique, since the light receiving element and the light emitting element are arranged in parallel to receive light, the LED cannot be used to function as a sensor while displaying.
JP 2001-197253 A

  The present invention has been made to solve such problems. A main object of the present invention is to provide a light emitting device capable of functioning as a sensor while exhibiting the display capability of a display.

  In order to achieve the above object, a first light emitting device with a sensor function according to the present invention includes a display unit in which a plurality of semiconductor light emitting elements are arranged vertically and horizontally in a predetermined pattern, and the semiconductor light emitting element of the display unit emits light. And a lighting control circuit capable of controlling lighting / extinguishing of the semiconductor light emitting element by controlling the lighting circuit. The light emitting device with a sensor function further includes a light reception detection circuit that generates a light reception signal generated by the photovoltaic power when the semiconductor light emitting element receives light and generates photovoltaic power. The lighting control circuit includes a sensor input for inputting different received light signals in the lighting period and the extinguishing period of the semiconductor light emitting element. The sensor input is electrically connected to the light reception detection circuit. The lighting control circuit can be switched in time division between a lighting mode in which the semiconductor light emitting element is turned on and a sensor mode in which the semiconductor light emitting element is turned off to function as a sensor. In the lighting mode, the lighting circuit is driven to the semiconductor light emitting element. In the sensor mode, the power supply from the lighting circuit to the semiconductor light-emitting element is stopped, and the light-receiving signal generated when the semiconductor light-emitting element receives light and generates photovoltaic power is detected. When the circuit is generated, it is configured to be able to detect that it is in a light receiving state by detecting this by sensor input. Accordingly, since the semiconductor light emitting element can be used for both lighting and sensor, high functionality can be realized at low cost and with a simple configuration without increasing the size of the display unit.

  In the second light emitting device with a sensor function, the light receiving detection circuit includes an amplifying circuit for amplifying a light receiving signal generated by the photovoltaic power when the semiconductor light emitting element receives light to generate the photovoltaic power. As a result, even if the received light signal detected by the semiconductor light emitting element is weak, it can be detected, and more accurate detection can be realized.

  Furthermore, in the third light emitting device with a sensor function, the lighting control circuit switches between the lighting mode and the sensor mode at a speed at which the human eye does not sense the blinking of the semiconductor light emitting element. Accordingly, the display unit can emit light and function as a sensor.

  Furthermore, in the light emitting device with a fourth sensor function, the lighting control circuit switches between the lighting mode and the sensor mode at a cycle of 100 Hz or more. Accordingly, the display unit can emit light and function as a sensor.

  Furthermore, in the fifth light emitting device with a sensor function, the semiconductor light emitting element can emit light in a plurality of different emission colors. Thereby, light of different colors can be detected in the light receiving mode and can be used for color detection.

  Furthermore, in the sixth light emitting device with a sensor function, the display unit has semiconductor light emitting elements arranged in a matrix. Thereby, a sensor function can be realized without providing a light receiving element such as a PD in the matrix display, and high-definition images and videos can be displayed by mounting LED chips at high density.

  Furthermore, in the seventh light emitting device with a sensor function, the semiconductor light emitting element is a light emitting diode. Light-emitting diodes are easy to obtain, have a long life, are resistant to mechanical vibrations, and can realize reliability and low cost.

  Furthermore, an eighth light emitting device with a sensor function includes a display unit in which a plurality of semiconductor light emitting elements are arranged vertically and horizontally in a predetermined pattern, and a lighting circuit capable of supplying drive power for causing the semiconductor light emitting elements of the display unit to emit light. And a lighting control circuit capable of controlling the lighting circuit to control turning on / off of the semiconductor light emitting element, wherein the lighting control circuit turns on / off the semiconductor light emitting element in a time-sharing manner. And a sensor input for inputting different received light signals between the lighting period and the extinguishing period of the semiconductor light emitting element, and the light emitting device with sensor function further includes the semiconductor light emitting element in the extinguishing period of one semiconductor light emitting element. When receiving a photoelectromotive force by receiving light, an amplification circuit for amplifying a received light signal generated by the photovoltaic power is provided, and the amplification circuit is electrically connected to the sensor input. In the lighting period, the semiconductor light-emitting element is driven in the lighting mode to drive the lighting circuit to supply power to the semiconductor light-emitting element so that the semiconductor light-emitting element is turned on. At the same time, when the semiconductor light emitting element receives light to generate photovoltaic power, the light receiving signal generated is amplified by an amplifier circuit and input to a sensor input so that the light receiving state can be detected. Accordingly, since the semiconductor light emitting element can be used for both lighting and sensor, high functionality can be realized at low cost and with a simple configuration without increasing the size of the display unit.

  Furthermore, in the ninth light emitting device with a sensor function, the display unit is a display for a shooting game. Thereby, a display for a shooting game can be configured at low cost.

  Furthermore, in the tenth light emitting device with a sensor function, the display unit is a display for clay shooting. Thereby, the display for clay shooting can be configured at low cost.

  Furthermore, in the eleventh light emitting device with sensor function, the display unit is a display for inputting handwritten characters. Thereby, a display for inputting handwritten characters can be configured at low cost.

  Furthermore, in the twelfth light emitting device with a sensor function, the display unit is a display for a touch panel. Thereby, the display for touch panels can be comprised at low cost.

  According to the light emitting device with a sensor function of the present invention, a semiconductor light emitting element can be used for both lighting and a sensor. In particular, since it is not necessary to provide a light receiving element such as a PD, the circuit configuration can be simplified at a low cost, and the mounting efficiency on the display surface can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a light emitting device with a sensor function for embodying the technical idea of the present invention, and the present invention does not specify the light emitting device with a sensor function as the following. Further, the present specification by no means specifies the members shown in the claims to the members of the embodiments. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the embodiments are not intended to limit the scope of the present invention unless otherwise specified, and are merely explanations. It's just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing.
(LED power generation)

  In addition to emitting light when energized, the LED also has power generation characteristics that generate an electromotive force when the LED is irradiated with light. Although this electromotive force is generally weak, it can be used as an optical sensor for measuring the intensity of light by amplifying it with an amplifier circuit.

  The power generation action of the LED will be described in detail with reference to FIG. FIG. 1 is a graph showing the voltage-current characteristics of an LED. When a general pn junction diode is irradiated with light having energy larger than the band gap energy, electrons in the valence band are excited to the conduction band, leaving holes in the original valence band. Thus, the pn junction diode has an effect of generating electricity by light irradiation. An LED is also a kind of pn junction diode, and thus has a power generation effect. However, since the light emission effect and the power generation effect are contradictory, the power generation effect, particularly the generated current value is small. Therefore, the sensitivity is lower than that of a light receiving element such as a PD, which is insufficient for applications such as measuring the amount of light received and measuring the intensity. However, it has practically sufficient performance for applications that only determine the presence or absence of incident light. The present invention intends to add a simple sensor function by utilizing such characteristics of a semiconductor light emitting element.

  Specifically, the voltage-current characteristic of the LED shifts downward as shown in FIG. 1 when the LED is irradiated with light. FIG. 1 shows that in the case of a red LED (Toshiba: TLRH190P), the open-circuit voltage is 1.3 to 1.4 (V) and the short-circuit current is in the reverse direction and is in the order of microamperes. LED emission and power generation occur simultaneously. However, in this example, the change in current when light is emitted when the LED emits light is compared to 20 mA when there is no light irradiation, and 19.9 mA when there is light irradiation. It is difficult to accurately detect the received light. In other words, in order for the LED to function as a sensor, it is preferable to turn off the LED. For this reason, in this embodiment, a short extinction period is provided during lighting, and the lighting / sensor function is switched in a time-sharing manner so that the sensor operates during this period.

In addition, the power generation effect is larger as the LED is larger in size, and the resin that covers the LED is more excellent in the transparent type than in the colored type. The wavelength sensitivity characteristic is high in sensitivity to light having a wavelength to emit light. FIG. 2 shows the results of measuring the wavelength dependence of the short circuit current. The LED used was TLRH190P (red LED) manufactured by Toshiba. As shown in this figure, the normalized short-circuit current and the light emission intensity have substantially the same peak wavelength, which confirms that the light emission peak wavelength and the light receiving sensitivity are substantially equal.
(Embodiment 1)

The present invention realizes a light emitting device with a sensor function by utilizing the above properties. Next, as Embodiment 1 of the present invention, a laser shooting competition target LED display will be described based on a perspective view of the display shown in FIG. 3 and a circuit diagram shown in FIG. The light emitting device 100 with a sensor function shown in these drawings includes a display unit 10 in which a plurality of semiconductor light emitting elements are arranged, a lighting circuit 20 that supplies driving power to the semiconductor light emitting elements, and a lighting control circuit 30 that controls the lighting circuit 20. And a light receiving detection circuit 40 for generating a light receiving signal generated when the semiconductor light emitting element receives light.
(Display unit 10)

  The display unit 10 has a plurality of semiconductor light emitting elements arranged in a predetermined pattern. In this example, LEDs are arranged two-dimensionally in a matrix. The display which draws a pattern is comprised by lighting each LED. The LED arrangement pattern may be a zigzag pattern (offset pattern), a spiral pattern, a concentric pattern, or the like, depending on the display application.

In addition, a color display can be configured by using a plurality of emission colors for the LEDs constituting the pixels of the display. In particular, if an LED capable of emitting light in RGB is used, a display capable of full color display can be obtained. In this example, an LED display for a laser shooting competition target is configured. The moving image on the LED display is laser-shot and if hit, the hit is notified by a change in sound and moving image. Moreover, it can be applied not only to a laser shooting competition but also to a shooting game.
(Semiconductor light emitting device)

  As the semiconductor light emitting element, an LED, an LD (semiconductor laser), or the like can be used. These semiconductor light emitting devices have the advantage that the linearity of the output with respect to the input is good, the efficiency is excellent, and the long life can be used stably. In particular, LEDs are preferable because they are inexpensive and readily available. Further, as the semiconductor light emitting element, a surface mount type (SMD) can be suitably used in addition to a bullet type (lamp type). In the example of FIG. 3 and the like, the LEDs are displayed in a circular shape for convenience, but it goes without saying that the shape of the LED chip may be rectangular.

Examples of the material of the semiconductor light emitting device include various semiconductors such as BN, SiC, ZnSe, GaN, InGaN, InAlGaN, AlGaN, BAlGaN, and BInAlGaN. Similarly, these elements may contain Si, Zn, or the like as an impurity element to serve as a light emission center. As a material of the light emitting layer, a nitride semiconductor (for example, a nitride semiconductor containing Al or Ga, a nitride semiconductor containing In or Ga, In _X Al _Y Ga _1-XY N (0 <X <1, 0 <Y < 1, X + Y ≦ 1), etc. The semiconductor structure is preferably a homostructure having a MIS junction, PIN junction or pn junction, heterostructure, or double hetero structure. The emission wavelength can be selected in various ways depending on the material and its mixed crystal ratio, and the output can be increased by adopting a single quantum well structure or a multiple quantum well structure in which the semiconductor active layer is formed in a thin film that produces a quantum effect. It can also be improved.
(Lighting circuit 20 and lighting control circuit 30)

The lighting circuit 20 supplies driving power for causing the semiconductor light emitting element of the display unit 10 to emit light. Here, a constant current source for current-driving the LED is provided. The lighting control circuit 30 controls the lighting circuit 20 to control ON / OFF of the semiconductor light emitting element and the duty ratio. PWM or PAM can be used for lighting control. The lighting circuit 20 and the lighting control circuit 30 can be integrated. Furthermore, the lighting control circuit 30 can also control lighting for each LED constituting the pixels of the display so that not only characters, figures, or still images but also moving images are displayed on the display. For this reason, an image display circuit 50 for displaying image information on a display may be provided. Alternatively, the display unit 10 can be used as a display as well as a display. It can also function as intelligent lighting that can adjust and change the color and brightness of the lighting. Such control can also be performed by the lighting control circuit 30.
(Lighting mode / sensor mode)

The lighting control circuit 30 can switch between a lighting mode in which the semiconductor light emitting element is turned on and a sensor mode in which the semiconductor light emitting element is turned off to function as a sensor in a time division manner. In the lighting mode, the lighting circuit 20 is driven to supply power to the semiconductor light emitting element to light it. In the sensor mode, the power supply from the lighting circuit 20 to the semiconductor light emitting element is stopped, and when the light reception detection circuit 40 generates a light reception signal generated when the semiconductor light emitting element receives light and generates photovoltaic power, This can be detected by the input 26 to detect that it is in a light receiving state. Further, the lighting control circuit 30 includes a sensor input 26 for inputting different received light signals between the lighting period and the extinguishing period of the semiconductor light emitting element.
(Light reception detection circuit 40)

The light reception detection circuit 40 generates a light reception signal generated by the photovoltaic power when the semiconductor light emitting element receives light and generates photovoltaic power. Further, the received light detection circuit 40 is electrically connected to the sensor input 26 of the controller 22 in order to transmit the generated received light signal to the controller 22 described later. The light receiving detection circuit 40 includes an amplifying circuit 42 for amplifying a light receiving signal generated by the photoelectromotive force when the semiconductor light emitting element receives light. This allows the amplified signal to be input to the sensor input 26.
(Circuit configuration)

  The operation principle of the lighting mode and the sensor mode will be described based on the circuit diagrams of FIGS. FIG. 5 shows a state in which one LED 12 is driven to be lit, and FIG. 6 shows a state in which this is operated as a sensor. The circuits shown in these drawings include an LED 12, a controller 22 as a lighting circuit and a lighting control circuit for driving the LED 12, and a transistor 44 as a light receiving detection circuit and an amplifier circuit. The controller 22 can use a microcomputer such as a PIC. In this example, a PIC16F84A manufactured by Microchip Technology Inc. was used.

The LED 12 has a cathode side connected to the ground side and an anode side connected to the I / O terminal 24 of the controller 22 via a protective resistor. The I / O terminal 24 of the controller 22 can be switched between input and output, and the current for driving the LED 12 can be supplied by setting the I / O terminal 24 to output. Further, the collector side of the transistor 44 is connected to the sensor input 26 of the controller 22. The emitter of the transistor 44 is grounded, and the base is connected to the anode side of the LED 12 via a protective resistor. More collector, a constant voltage of V _cc (for example, 5V) is applied via a protective resistor.

  In the lighting mode, by setting the I / O terminal 24 to HIGH, the current supplied from the I / O terminal 24 flows through the LED 12 as shown in FIG. At this time, since the transistor 44 is turned off, the sensor input 26 remains HIGH.

  On the other hand, in the sensor mode, when the I / O terminal 24 of the controller 22 is input and set to LOW, power is not supplied to the LED 12 and the LED 12 is turned off. During this time, when light enters the LED 12, a photovoltaic force is generated, and a reverse current flows from the cathode to the anode. Since the reverse current is a weak electrical signal, the transistor 44 is used to amplify it. Specifically, the current branched from the anode is supplied to the base side of the transistor 44, so that the transistor 44 is turned on. As a result, the collector potential drops below 5V due to the voltage drop, and the sensor input 26 Switches from HIGH to LOW. As described above, when light reception is detected by the LED 12, the sensor input 26 changes from HIGH to LOW. Therefore, this change can be detected to detect the light reception state. For example, it is possible to detect that light has entered, or to detect that light has been blocked, and to perform various controls using the sensor input 26 as a trigger.

For example, every time the light shielding is detected, the LED is turned on / off in a toggle shape. Alternatively, the displayed image or moving image can be changed. In order to increase the current amplification factor, a Darlington amplifier using a plurality of transistors connected in Darlington to form an emitter follower direct-coupled current amplifier can be used.
(Time division)

  By switching between the lighting mode and the sensor mode at high speed, it is possible to make the human eye appear to be constantly lit without being aware of the extinguishing period. This makes it possible to cause the sensor operation to function in the background and perform necessary processing. The switching speed is set to a frequency at which human eyes do not notice blinking, for example, 100 Hz or more, preferably 1 kHz or more. For this reason, the lighting control circuit 30 has a configuration capable of driving the LEDs in this cycle. By operating at a high frequency, the transformer can be miniaturized and the circuit can be miniaturized.

Switching between the lighting mode and the sensor mode is performed by the lighting control circuit 30. The manner in which the lighting control circuit 30 switches between the lighting mode and the sensor mode will be described based on the timing chart of FIG. FIG. 7 shows the lighting timing of the LED and the input timing of the received light signal. As shown in this figure, the LED receives a drive signal from the lighting circuit 20 at a period T. The amount of light can be controlled by controlling the pulse width of the lighting period t _{on by} PWM control. On the other hand, the LED functions as a light receiving element during the extinguishing period t _off . When a light reception signal is detected during the t _off period, the light reception signal amplified by the amplifier circuit 42 is sent to the lighting control circuit 30 to detect light reception.
(LED display for laser shooting competition targets)

Laser shooting competition uses a laser rifle 60 that uses laser light instead of bullets. As this target (target), a target-like display has been conventionally used as a shooting target. However, since the light receiving element and the light emitting element are arranged, there is a problem that the display becomes large. On the other hand, in this embodiment, as shown in FIG. 3, a display in which only LEDs are arranged in a matrix is used, and these LEDs are also used as sensors in a time-sharing manner, thereby arranging individual light receiving elements. The target can be constructed without any problem, and a compact and efficient mounting target can be constructed. This LED display displays a moving image simulating clay as a target pattern for shooting. By switching the lighting mode and the sensor mode at a cycle of, for example, 1 kHz, the display appears to the athlete's eyes as a moving image is always displayed. Athletes aim at this moving image and irradiate a directional beam such as a beam rifle. The light irradiation time is longer than one cycle of the sensor mode of the display. Thereby, irradiation of a light beam can be detected in the sensor mode of the display. It is determined that the shooting has failed when the LED in which light is detected among the LEDs constituting the display is not included in the pixel displaying the target pattern. On the other hand, if it corresponds to a pixel, it is determined that it has been hit, and necessary processing is performed. For example, the image is changed to a moving image in which the clay is destroyed, and “hit” is displayed on the screen. Also, by providing an audio output circuit, it is possible to output a clay breaking sound from the speaker at the same time as the hit. Thereby, virtual shooting can be reproduced. In terms of processing, using the input signal of the sensor input 26 as a trigger, an interrupt for outputting a hit sound or image to the audio output circuit or the image display circuit 50 is performed. Further, the image display circuit 50 can display the target object pattern by changing the speed or image of the target object for each level.
(shooting game)

The same configuration is not limited to laser shooting competitions, and can be used for, for example, shooting games. For example, by applying this embodiment as a display for an arcade game, an image can be displayed on the display and a function for detecting the irradiation position of a light beam from a gun that irradiates a laser beam can be provided. realizable.
(Embodiment 2)

Next, as Embodiment 2, an example applied to a handwriting input display will be described with reference to FIG. In contrast to the above, the display unit 210 shown in FIG. That is, when the user traces the display surface with a finger or the like, it is detected that the LED in that portion has been blocked from outside light, and the LED is turned on. Moreover, you may turn off instead of lighting. Alternatively, the lighting color can be changed, or the display can be changed from being constantly lit to blinking. In this way, the part instructed by the user in the display can be changed to a display different from the others. Therefore, as shown in FIG. 8, when the user continuously traces on the display, the locus can be displayed. Using this, handwritten input can be realized. It can also be used as a touch panel.
(Embodiment 3)

  Furthermore, as Embodiment 3, an example in which the present invention is applied to a color identification device that performs color discrimination will be described with reference to FIG. The color identification device includes a plurality of LEDs 312 that can emit light of different colors, a lighting circuit 320 for causing them to emit light, a light reception detection circuit 340 for causing each LED 312 to function as a light receiving element, and a light reception signal from each LED 312. And a processing circuit 330 for specifying the color of the object W by signal processing.

  The operation principle of this color identification device will be described. When the object W is irradiated with white light, light having a wavelength corresponding to the color of the object W is reflected. Therefore, if this wavelength is detected by the LED 312 for each color component as shown in FIG. Color information. Here, a type capable of emitting light for each of RGB is used as the LED 312. The LED 312 can be used in a single package in which LED chips that emit light in R, G, and B are incorporated, or in combination with separate R, G, and B LED chips. As described above, the characteristics of the light emission color and the light reception wavelength of the LED are substantially the same. Therefore, red, green, and blue LEDs can be used as light-receiving elements having wavelength dependency corresponding to the respective colors due to the difference in band gaps. Therefore, the color of the object W can be determined by measuring each received signal, analyzing the magnitudes of the three types of RGB signals, and comparing them with the reference data. In this way, the present invention is not limited to use as a display, but can also be used as a light receiving element or an imaging element, and can realize functions similar to those of a CCD or CMOS. In particular, it can be suitably used for a device such as a digital camera or a camera-equipped mobile phone in which a light emitter such as a flash and an image pickup device for photographing images and moving images are provided.

  Further, since this color identification device can use an LED as a light source, it is of a built-in light source and can be used at night. Furthermore, the influence on the surroundings can be minimized by narrowing the width of the irradiation pulse.

  In order to improve the measurement accuracy, the irradiation light is preferably pulsed. In addition, the light emitting side LED and the light receiving side LED are switched at short intervals, the measurement results are compared with each other, and if a large difference occurs, the measurement is repeated. By introducing a reversible process of measurement, the “probability” of color identification can be improved. In this way, the degree of utilization as an image-capturing element capable of color identification instead of a CCD or the like is increased.

Furthermore, it can be used not only for color information of the object W but also for identifying the surface shape. As shown in FIG. 11, by arranging a plurality of LEDs spatially separated from each other, each LED can be used as a light receiving element, and the color and surface shape of the object W can be identified by analyzing each signal. become.
(Embodiment 4)

  Furthermore, as Embodiment 4, an example applied to a surface shape measuring apparatus will be described with reference to FIG. The surface shape measuring apparatus shown in this figure is detected by an LED board 14 in which LEDs are two-dimensionally arranged, a lighting circuit 420 for lighting each LED, a light receiving detection circuit 440 that functions as a light receiving element, and a light receiving detection circuit 440. A data storage circuit 470 for collecting the received light reception signals, and a processing circuit 430 for processing the data stored in the data storage circuit 470. The LED board 14 arranges each LED two-dimensionally at equal intervals, as shown in FIG. During operation, the LEDs on the LED board 14 are lit in order at appropriate time intervals. At this time, the spatial distribution of the reflected light is obtained by causing the unlit LED to function as a light receiving element. Based on this spatial distribution, the surface shape of the object to be measured can be analyzed without contact.

  Furthermore, at this time, the measurement accuracy can be improved by setting the LED drive pulse to at least two levels, causing each LED to emit light in two stages, and using the difference between the received light signals as data. Since this surface shape measuring device does not require the use of a light receiving PD separately, the arrangement interval of the LEDs can be reduced, and a measuring device with high measurement accuracy and low cost can be realized. Further, when it is desired to measure a large object W, a driving device 580 for moving the object W can be added as shown in FIG. In the example of this figure, an XY movement stage for placing the object W and moving it to the XY plane is provided.

  The light emitting device with sensor function of the present invention is a handwritten input type LED display or touch panel in which the LED of the part touched with a finger is turned on / off, a target for laser shooting competition using a laser beam instead of a real bullet, a display for a shooting game, It can be suitably applied to objects, toys, etc. using LEDs.

It is a graph which shows the voltage-current characteristic of LED. It is a graph which shows the light emission wavelength and absorption wavelength of LED. It is a perspective view which shows the LED display for laser shooting competition targets which concerns on Embodiment 1 of this invention. It is a circuit diagram of the LED display for laser shooting competition targets shown in FIG. It is a circuit diagram which shows the lighting state of LED which comprises the LED display of FIG. It is a circuit diagram which shows the light reception state of LED which comprises the LED display of FIG. It is a timing chart which shows the mode of switching to lighting mode and sensor mode. It is a perspective view which shows the display for handwriting input which concerns on Embodiment 2 of this invention. It is a block diagram which shows the color identification apparatus which concerns on Embodiment 3 of this invention. It is a wave form diagram which shows the pulse of irradiation light, and the light reception signal of each LED of RGB which received this. It is a schematic diagram which shows the state which identifies the surface shape of a target object. It is a block diagram which shows the surface shape measuring apparatus which concerns on Embodiment 4 of this invention. It is a schematic diagram which shows the two-dimensional arrangement | sequence of LED of an LED board. It is a block diagram which shows the surface shape measuring apparatus which added the drive device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Light-emitting device with a sensor function 10, 210 ... Display part 12, 312 ... LED
DESCRIPTION OF SYMBOLS 14 ... LED board 20, 320, 420 ... Lighting circuit 22 ... Controller 24 ... I / O terminal 26 ... Sensor input 30 ... Lighting control circuit 40, 340, 440 ... Light reception detection circuit 42 ... Amplifying circuit 44 ... Transistor 50 ... Image display Circuit 60 ... Laser rifle 330, 430 ... Processing circuit 470 ... Data storage circuit 580 ... Drive device W ... Object

Claims (12)

A display unit in which a plurality of semiconductor light emitting elements are arranged vertically and horizontally in a predetermined pattern;
A lighting circuit capable of supplying driving power for causing the semiconductor light emitting element of the display unit to emit light;
A light emitting device with a sensor function comprising a lighting control circuit capable of controlling lighting / extinguishing of a semiconductor light emitting element by controlling the lighting circuit;
Furthermore, when the semiconductor light emitting element receives light to generate photovoltaic power, the semiconductor light emitting element includes a light receiving detection circuit that generates a light receiving signal generated by the photovoltaic power,
The lighting control circuit includes a sensor input for inputting different received light signals in the lighting period and the extinguishing period of the semiconductor light emitting element,
The sensor input is electrically connected to the light reception detection circuit,
The lighting control circuit can be switched in time division between a lighting mode for lighting the semiconductor light emitting element and a sensor mode for turning off and functioning as a sensor,
In the lighting mode, the lighting circuit is driven to supply power to the semiconductor light emitting element to light it,
In the sensor mode, when the light reception detection circuit generates a light reception signal generated by stopping the power supply from the lighting circuit to the semiconductor light emitting element and receiving light by the semiconductor light emitting element, A light emitting device with a sensor function, wherein the light emitting device is configured to be able to detect the light receiving state by detecting the sensor input. The light emitting device with sensor function according to claim 1,
The light receiving device with a sensor function, wherein the light receiving detection circuit includes an amplifying circuit for amplifying a light receiving signal generated by the photovoltaic power when the semiconductor light emitting element receives light and generates photovoltaic power. The light emitting device with sensor function according to claim 1 or 2,
The light-emitting device with a sensor function, wherein the lighting control circuit switches between a lighting mode and a sensor mode at a speed at which human eyes do not sense blinking of a semiconductor light-emitting element. A light emitting device with a sensor function according to any one of claims 1 to 3,
The light-emitting device with a sensor function, wherein the lighting control circuit switches between a lighting mode and a sensor mode at a cycle of 100 Hz or more. A light emitting device with a sensor function according to any one of claims 1 to 4,
The light emitting device with a sensor function, wherein the semiconductor light emitting element can emit light in a plurality of different emission colors. A light emitting device with a sensor function according to any one of claims 1 to 5,
The light emitting device with a sensor function, wherein the display section includes the semiconductor light emitting elements arranged in a matrix. A light emitting device with a sensor function according to any one of claims 1 to 6,
The light emitting device with a sensor function, wherein the semiconductor light emitting element is a light emitting diode. A display unit in which a plurality of semiconductor light emitting elements are arranged vertically and horizontally in a predetermined pattern;
A lighting circuit capable of supplying driving power for causing the semiconductor light emitting element of the display unit to emit light;
A lighting control circuit capable of controlling lighting / extinguishing of the semiconductor light emitting element by controlling the lighting circuit;
A light emitting device with a sensor function comprising:
The lighting control circuit includes a sensor input for controlling lighting / extinguishing of the semiconductor light emitting element in a time-sharing manner, and for inputting different received light signals in the lighting period and the extinguishing period of the semiconductor light emitting element,
The light emitting device with sensor function further includes
When the semiconductor light emitting element receives light and generates photovoltaic power during the extinguishing period of one semiconductor light emitting element, the semiconductor light emitting element includes an amplification circuit for amplifying a received light signal generated by the photovoltaic power,
The amplifier circuit is electrically connected to the sensor input;
The lighting control circuit is
In the lighting period, the semiconductor light emitting element is driven in the lighting mode to drive the lighting circuit to supply power to the semiconductor light emitting element to light it,
In the extinguishing period, the semiconductor light emitting element is set in the sensor mode to stop power supply, and when the semiconductor light emitting element receives light and generates photovoltaic power, the light receiving signal generated is amplified by the amplifier circuit, A light emitting device with a sensor function, wherein a light receiving state can be detected by inputting to a sensor input. A light emitting device with a sensor function according to any one of claims 1 to 8,
The light emitting device with a sensor function, wherein the display unit is a display for a shooting game. A light emitting device with a sensor function according to any one of claims 1 to 8,
A light emitting device with a sensor function, wherein the display unit is a display for clay shooting. A light emitting device with a sensor function according to any one of claims 1 to 8,
The light emitting device with a sensor function, wherein the display unit is a display for inputting handwritten characters. A light emitting device with a sensor function according to any one of claims 1 to 8,
The light emitting device with a sensor function, wherein the display unit is a display for a touch panel.

Images