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WO2014188756A1 - Capteur optique et appareil d'affichage - Google Patents

Capteur optique et appareil d'affichage Download PDF

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Publication number
WO2014188756A1
WO2014188756A1 PCT/JP2014/055606 JP2014055606W WO2014188756A1 WO 2014188756 A1 WO2014188756 A1 WO 2014188756A1 JP 2014055606 W JP2014055606 W JP 2014055606W WO 2014188756 A1 WO2014188756 A1 WO 2014188756A1
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WO
WIPO (PCT)
Prior art keywords
light
light receiving
receiving element
optical sensor
photocurrent
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2014/055606
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English (en)
Japanese (ja)
Inventor
井上　高広
佐藤　秀樹
浩一朗 杉本
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sharp Corp
Original Assignee
Sharp Corp
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Filing date
Publication date
Application filed by Sharp Corp filed Critical Sharp Corp
Publication of WO2014188756A1 publication Critical patent/WO2014188756A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/94—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
    • H03K17/941—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated using an optical detector
    • H03K17/943—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated using an optical detector using a plurality of optical emitters or detectors, e.g. keyboard
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/02—Details
    • G01J1/04—Optical or mechanical part supplementary adjustable parts
    • G01J1/0407—Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
    • G01J1/0411—Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings using focussing or collimating elements, i.e. lenses or mirrors; Aberration correction
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/02—Details
    • G01J1/04—Optical or mechanical part supplementary adjustable parts
    • G01J1/0488—Optical or mechanical part supplementary adjustable parts with spectral filtering
    • G01J1/0492—Optical or mechanical part supplementary adjustable parts with spectral filtering using at least two different filters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
    • G01J1/4204—Photometry, e.g. photographic exposure meter using electric radiation detectors with determination of ambient light
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
    • G01J5/0022—Radiation pyrometry, e.g. infrared or optical thermometry for sensing the radiation of moving bodies
    • G01J5/0025—Living bodies
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
    • G01J5/02—Constructional details
    • G01J5/08—Optical arrangements
    • G01J5/0896—Optical arrangements using a light source, e.g. for illuminating a surface
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V8/00—Prospecting or detecting by optical means
    • G01V8/10—Detecting, e.g. by using light barriers
    • G01V8/20—Detecting, e.g. by using light barriers using multiple transmitters or receivers
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/06—Adjustment of display parameters
    • G09G2320/0626—Adjustment of display parameters for control of overall brightness
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/06—Adjustment of display parameters
    • G09G2320/0666—Adjustment of display parameters for control of colour parameters, e.g. colour temperature
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02—Details of power systems and of start or stop of display operation
    • G09G2330/021—Power management, e.g. power saving
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2360/00—Aspects of the architecture of display systems
    • G09G2360/14—Detecting light within display terminals, e.g. using a single or a plurality of photosensors
    • G09G2360/144—Detecting light within display terminals, e.g. using a single or a plurality of photosensors the light being ambient light
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2360/00—Aspects of the architecture of display systems
    • G09G2360/14—Detecting light within display terminals, e.g. using a single or a plurality of photosensors
    • G09G2360/145—Detecting light within display terminals, e.g. using a single or a plurality of photosensors the light originating from the display screen
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/3406—Control of illumination source
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G5/00—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators
    • G09G5/10—Intensity circuits
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K2217/00—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00
    • H03K2217/94—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00 characterised by the way in which the control signal is generated
    • H03K2217/941—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00 characterised by the way in which the control signal is generated using an optical detector
    • H03K2217/94102—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00 characterised by the way in which the control signal is generated using an optical detector characterised by the type of activation
    • H03K2217/94108—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00 characterised by the way in which the control signal is generated using an optical detector characterised by the type of activation making use of reflection

Definitions

  • the present invention relates to an optical sensor used for proximity detection and illuminance measurement.
  • Mobile terminals such as mobile phones and digital cameras use liquid crystal panels as information display devices.
  • a proximity sensor In such a portable terminal, by installing a proximity sensor, there is a demand for detecting a situation where a user brings a face close to the portable terminal, suppressing display on the liquid crystal panel, and reducing power consumption of the portable terminal. is increasing.
  • the above-described mobile terminal is equipped with an illuminance sensor to measure the illuminance of the environment where the liquid crystal panel is used, and to control the amount of light emitted from the backlight included in the liquid crystal panel according to the measurement result.
  • an illuminance sensor to measure the illuminance of the environment where the liquid crystal panel is used, and to control the amount of light emitted from the backlight included in the liquid crystal panel according to the measurement result.
  • FIG. 15 is a circuit diagram showing the main part of the optical sensor according to the prior art described in Patent Document 1.
  • the optical sensor described in Patent Document 1 includes two light receiving elements PD1 and PD2 having different spectral characteristics (spectral sensitivity characteristics) and a current mirror circuit, and receives light via the current mirror circuit.
  • a current ⁇ ⁇ Iin1 obtained by multiplying the amplitude of the photocurrent Iin1 generated by the element PD1 by ⁇ is obtained and subtracted from the photocurrent Iin2 generated by the light receiving element PD2 to obtain a current (Iin2- ⁇ ⁇ Iin1).
  • the spectral characteristic of the photosensor becomes a spectral characteristic that combines the spectral characteristics of the respective light receiving elements.
  • the light receiving element PD1 is disposed so as to be sandwiched between the light receiving elements PD2. Thereby, even when the amount of incident light to the light receiving element is not uniform, the bias of the photocurrent generated from the light receiving element is reduced.
  • FIG. 16 is a plan view showing a main part of a conventional optical sensor described in Patent Document 2.
  • the optical sensor described in Patent Document 2 includes two light receiving elements PD1 and PD2 that are equally distributed in a plane and have different spectral characteristics, and a photocurrent generated from the light receiving element PD1. Then, a current obtained by directly subtracting the photocurrent generated from the light receiving element PD2 is obtained. Thereby, the spectral characteristic of the photosensor becomes a spectral characteristic that combines the spectral characteristics of the respective light receiving elements.
  • the light receiving elements PD1 and PD2 are evenly arranged in a plane, and even if the angle of incident light to the light receiving element is biased, the photocurrent generated from the light receiving element is biased. Reduced.
  • Japanese Patent Publication Japanese Patent Laid-Open No. 2007-73591 (published March 22, 2007)” Japanese Patent Publication “JP 2009-182189 (released on August 13, 2009)”
  • the light sensor reflects the light emitted from the light emitting element to the object and receives the reflected light by the light receiving element, thereby detecting that the object is close.
  • Such an optical sensor may be used by being incorporated in a casing of a mobile terminal, for example.
  • the light emitted from the light emitting element may be reflected by the housing, and the light receiving element may receive the reflected light.
  • the possibility that the light receiving element receives such reflected light as a disturbance is not taken into consideration, and the optical sensor does not reflect the reflected light from the object whose proximity should be detected.
  • the optical sensor does not reflect the reflected light from the object whose proximity should be detected.
  • the reflected light from the body cannot be distinguished and the proximity of the object cannot be detected accurately.
  • the spectral characteristics and the arrangement position of the light receiving element are fixed. Therefore, when the amount of incident light to the light receiving element is not uniform, or the angle of the incident light to the light receiving element is If it is biased, the bias of the photocurrent generated from the light receiving element is not sufficiently reduced.
  • the light sensor is configured such that the light receiving elements PD1 and PD2 are uniformly included in a plane of incidence (lens spot) of the light, but the lens spot is shifted. In this case, the photocurrent generated from the light receiving element is biased.
  • the possibility that the light receiving element receives the light with the lens spot shifted as a disturbance is not sufficiently considered, and the optical sensor accurately determines the illuminance. There is a problem that it cannot be measured.
  • the present invention has been made in view of the above-described problems, and an object of the present invention is to provide an optical sensor capable of suppressing adverse effects caused by disturbance light in proximity detection and illuminance measurement.
  • an optical sensor includes a substrate and measures an amount of received light, and the photosensor is arranged on the substrate and receives photocurrent.
  • FIG. 1 is utilized for illumination intensity measurement. It is a graph which shows the spectral characteristic of the light receiving element when the optical sensor shown in FIG. 1 is utilized for illumination intensity measurement. It is a top view which shows the structure of the principal part of the optical sensor which concerns on other embodiment of this invention. It is a top view which shows the other structure of the principal part of the optical sensor shown in FIG. It is a figure which shows the structure of the modification of the analog-digital conversion part shown in FIG. 9 and FIG. It is a wave form diagram which shows the operation
  • FIG. 12 is a waveform diagram of a digital signal or the like output in proximity detection by the analog-digital conversion unit shown in FIGS.
  • FIG. 1 is a plan view showing a configuration of an optical sensor 1 according to an embodiment of the present invention.
  • the optical sensor 1 includes a light receiving element group PDG and a control unit 10.
  • the light receiving element group PDG includes 16 light receiving elements (PDs 11 to 14, 21 to 24, 31 to 34, 41 to 44) arranged on a substrate (described later in FIG. 4).
  • “light receiving element PD” means any one of the 16 light receiving elements.
  • the configuration is not limited to the configuration illustrated in FIG. 1, and the light receiving element group PDG only needs to include at least two, that is, a plurality of light receiving elements.
  • a region D represents a region on the substrate on which 16 light receiving elements are arranged.
  • the control unit 10 includes a light receiving element selecting unit (light receiving element selecting unit) 11, a spectral characteristic setting unit (spectral characteristic setting unit) 12, and a received light amount calculating unit (received light amount calculating unit) 13.
  • the light sensor measures the amount of light received based on the photocurrent generated from each light receiving element.
  • the directions of the X axis and the Y axis are directions representing a plane in which the region D is widened, and the direction of the Z axis is a normal direction of the light receiving surface of each light receiving element, which are shown in other drawings. Corresponds to the X to Z axis directions.
  • the light receiving element PD will be described in detail.
  • FIG. 2 is a cross-sectional view showing the configuration of the light receiving element PD of the optical sensor 1 shown in FIG.
  • the light receiving element PD has a configuration of P substrate (Psub) -N well (Nwell) -P diffusion (Pdif), and a PN junction between the P substrate (Psub) and the N well (Nwell).
  • the switching unit SWS includes a switch SWa and a switch SWb.
  • the switching unit SWS is connected to the spectral characteristic setting unit 12 (see FIG. 1), and the spectral characteristic setting unit 12 switches ON / OFF of each switch. Thereby, the spectral characteristic setting unit 12 sets the spectral characteristic of the light receiving element PD.
  • the “spectral characteristic of the light receiving element PD” means the relationship between the wavelength of light of a certain amount of light and the magnitude of the input current (photocurrent) Iin that the light receiving element PD receives and generates the light. Further, “setting the spectral characteristics of the light receiving element PD” means that the magnitude of the input current Iin that the light receiving element PD receives and generates light of a certain amount of light with respect to a wavelength included in a predetermined range. It means setting. Below, each element with which light receiving element PD is provided is demonstrated in detail.
  • the infrared light receiving PN junction PDir has infrared spectral characteristics. This is because infrared light included in the light incident on the light receiving element PD propagates to a deeper layer (negative direction of the Z axis) of the light receiving element PD as compared with visible light.
  • the “infrared spectral characteristics” means that the magnitude of the photocurrent generated by the infrared light receiving PN junction PDir receiving and generating a fixed amount of infrared light is the same as that of the infrared light receiving PN junction PDir.
  • the wavelength of the light received by the PN junction PDir for receiving infrared light which is larger than the magnitude of the photocurrent generated by receiving light of light quantity and not infrared light, and the magnitude of the generated photocurrent Means the relationship.
  • the visible light receiving PN junction PDvis has visible spectral characteristics. This is because visible light included in the light incident on the light receiving element PD does not propagate to the deep layer side of the light receiving element PD as much as infrared light.
  • the “visible spectral characteristic” means that the magnitude of the photocurrent generated by the visible light receiving PN junction PDvis receiving and generating a certain amount of visible light is the same as the visible light receiving PN junction PDvis. This means the relationship between the wavelength of light received by the visible light receiving PN junction PDvis and the magnitude of the photocurrent, which is larger than the magnitude of the photocurrent generated by receiving light that is not visible light.
  • the switching unit SWS uses the switch SWa and the switch SWb to switch the connection state between the infrared light receiving PN junction PDir and the visible light receiving PN junction PDvis.
  • the switch SWa is connected between the node N0 and the node N2.
  • the node N0 is connected to the cathode of the visible light receiving PN junction PDvis through the node N1.
  • the node N2 is connected to the anode of the visible light receiving PN junction PDvis. Therefore, when the switch SWa is turned on and the switch SWb is turned off, the potential of the cathode and the anode of the visible light receiving PN junction PDvis becomes the same, so that a photocurrent is generated from the visible light receiving PN junction PDvis. Only the photocurrent generated from the infrared light receiving PN junction PDir is output as the input current Iin to the node N0. Thereby, the spectral characteristics of the light receiving element PD can be changed to infrared spectral characteristics.
  • the “infrared spectral characteristics” means that the magnitude of the input current Iin that the light receiving element PD receives and generates a fixed amount of infrared light is that the light receiving element PD is the light of the constant light amount. This means the relationship between the wavelength of light received by the light receiving element PD and the magnitude of the input current Iin to be generated, which is larger than the magnitude of the input current Iin that is received and generated by the light.
  • the switch SWb is connected between the node N2 and the ground. Therefore, when the switch SWa is turned off and the switch SWb is turned on, a current obtained by adding the photocurrent generated from the visible light receiving PN junction PDvis and the photocurrent generated from the infrared light receiving PN junction PDir. Is output as the input current Iin to the node N0. As a result, the spectral characteristics of the light receiving element PD can be changed from visible to infrared.
  • the “visible to infrared spectral characteristics” means that the magnitude of the input current Iin that is generated when the light receiving element PD receives visible to infrared light with a constant light amount is that the light receiving element PD receives the light with the constant light amount. This means the relationship between the wavelength of light received by the light receiving element PD and the magnitude of the input current Iin to be generated, which is larger than the magnitude of the input current Iin that is received and generated by light that is not visible to infrared light. .
  • visible to infrared light means light included in visible light or infrared light.
  • the light receiving element selection unit 11 selects some of the light receiving elements among the plurality of light receiving elements included in the light receiving element group PDG. Note that the light receiving element selection unit 11 may select a plurality of light receiving elements.
  • the light receiving element selection unit 11 is connected to the received light amount calculation unit 13 and transmits information indicating which light receiving element is the selected light receiving element to the received light amount calculation unit 13.
  • the spectral characteristic setting unit 12 is connected to a switching unit SWS included in the light receiving element PD, and sets the spectral characteristics of 16 light receiving elements included in the light receiving element group PDG.
  • the spectral characteristic setting unit 12 may collectively set the spectral characteristics of a plurality of light receiving elements.
  • the spectral characteristic setting unit 12 is connected to the received light amount calculation unit 13 and transmits information indicating what spectral characteristic the spectral characteristic set in the light receiving element PD is to the received light amount calculation unit 13. .
  • the light receiving element selection unit 11 and the spectral characteristic setting unit 12 are connected to each other, and the spectral characteristic setting unit 12 determines what spectral characteristics are set for the light receiving element selected by the light receiving element selection unit 11. Information indicating whether the light has spectral characteristics is transmitted to the received light amount calculation unit 13.
  • the received light amount calculation unit 13 waits for a photocurrent generated from the light receiving element selected by the light receiving element selection unit 11 and whose spectral characteristics are set by the spectral characteristic setting unit 12, and receives the amount of light received by the optical sensor 1. Calculate
  • optical sensor 1 With the optical sensor 1 having the above-described configuration and the method of measuring the amount of received light using the optical sensor 1, adverse effects caused by light that becomes a disturbance can be suppressed in proximity detection and illuminance measurement.
  • operations when the optical sensor 1 is used for proximity detection and illuminance measurement will be described in order.
  • FIG. 3 is a plan view showing an operation when the optical sensor 1 shown in FIG. 1 is used for proximity detection.
  • the optical sensor 1 includes a light emitting element LED that emits at least infrared light, and an LED drive circuit DC that drives the light emitting element LED.
  • a light emitting diode may be used as the light emitting element LED.
  • the optical sensor 1 may include a plurality of light emitting elements LED.
  • the light receiving element selection unit 11 (see FIG. 1), among the 16 light receiving elements included in the light receiving element group PDG, a part of the light receiving elements (PD13) arranged in the region Da on the light emitting element side of the region D. , 14, 23, 24, 33, 34, 43, 44).
  • the spectral characteristic setting unit 12 (see FIG. 1) sets infrared spectral characteristics as the spectral characteristics of the light receiving element selected by the light receiving element selecting unit 11.
  • the optical sensor 1 is designed so that light enters the range indicated by the light spot S.
  • other light may further enter the range indicated by the light spot Sa due to the cause described later. That is, the light incident on the range indicated by the light spot Sa is light that causes disturbance, and can cause the optical sensor 1 to malfunction.
  • the optical sensor 1 can suppress an adverse effect caused by light that becomes a disturbance in proximity detection.
  • this principle will be described in detail.
  • FIG. 4 is a cross-sectional view showing an operation when the optical sensor 1 shown in FIG. 1 is used for proximity detection.
  • the optical sensor 1 reflects the light emitted from the light emitting element LED to the proximity detection object 41 and receives the reflected light by the light receiving element group PDG arranged on the substrate 21, thereby making the proximity It detects that the detection object 41 is approaching.
  • Such an optical sensor 1 may be used by being incorporated in, for example, a mobile panel housing 31 that is a housing of a mobile terminal. Note that “inside the mobile panel casing 31” means a space on the negative side of the Z axis with respect to the mobile panel casing 31 in FIG.
  • the optical sensor 1 is incorporated in the portable panel casing 31 with a distance d from the portable panel casing 31.
  • the case reflected light emitted from the light emitting element LED and reflected by the portable panel casing 31 enters the light receiving element group PDG, and the light receiving element group PDG is emitted from the light emitting element LED and is a proximity detection object outside the casing.
  • a photocurrent similar to the photocurrent generated when the object reflected light reflected by 41 is incident on the light receiving element may be generated.
  • the conventional optical sensor cannot distinguish between the case reflected light and the object reflected light, and erroneously detects that the proximity detection object 41 is close even if it is not close to the optical sensor.
  • FIG. 5 is a cross-sectional view showing another operation when the optical sensor 1 shown in FIG. 1 is used for proximity detection.
  • the distance da between the optical sensor 1 and the portable panel housing 31 is larger than the distance d shown in FIG. Narrow.
  • the angle ⁇ a formed by the case reflected light with the portable panel case 31 is smaller than the angle ⁇ shown in FIG.
  • the case reflected light shown in FIG. 5 enters the light receiving element group PDG, the case reflected light is further away from the light emitting element LED side in the negative direction of the X axis than the case reflected light shown in FIG. Incident.
  • the optical sensor tends to be used by being incorporated in a smaller portable terminal, the reflected light from the casing may be incident on a position further away from the light emitting element LED side in the negative direction of the X axis. high.
  • the light receiving element selection unit 11 is a part of the 16 light receiving elements included in the light receiving element group PDG that is arranged in the area Da on the light emitting element LED side of the area D.
  • the received light amount calculation unit 13 In order to select the light receiving element (see FIG. 3), that is, the light receiving element that is less likely to receive the case reflected light than other light receiving elements, the received light amount calculation unit 13 (see FIG. 1) In this calculation, the influence of the case reflected light can be suppressed. In other words, the optical sensor 1 adjusts the optical characteristics so as to positively receive object reflected light by selecting some of the 16 light receiving elements arranged in the region D. In addition, it is possible to reduce the received light amount of the case reflected light that becomes noise in the measurement of the received light amount.
  • FIG. 6 is a cross-sectional view showing an operation when the optical sensor 101 according to the comparative example of the optical sensor 1 shown in FIG. 1 is used for proximity detection.
  • the optical sensor 101 is different from the optical sensor 1 in that it includes a shielding object 102.
  • the shield 102 prevents the case reflected light from entering the light receiving element group PDG.
  • the photosensor 1 may not be provided with the shield 102.
  • the configuration according to the comparative example cannot often be employed.
  • the increased cost of incorporating the shielding object 102 into the optical sensor cannot be allowed.
  • the optical sensor 1 may be used in an environment where, for example, visible light emitted from a fluorescent lamp enters the light receiving element PD.
  • the spectral characteristic setting unit 12 sets the infrared spectral characteristic as the spectral characteristic of the light receiving element selected by the light receiving element selection unit 11 (see FIG. 1).
  • the light receiving element suppresses generation of a photocurrent caused by visible light, and selectively receives infrared light emitted from the light emitting element LED (see FIG. 3) to generate a photocurrent. Therefore, the received light amount calculation unit 13 (see FIG. 1) can suppress the influence of visible light in the calculation of the received light amount.
  • the optical sensor 1 is suitable for proximity detection because it can suppress erroneous detection due to visible light.
  • the optical sensor can suppress adverse effects caused by the reflected light from the housing and is suitable for proximity detection.
  • FIG. 7 is a plan view showing an operation when the optical sensor 1 shown in FIG. 1 is used for illuminance measurement.
  • the light receiving element selection unit 11 receives the light received in a part of the region Db near the center of the region D among the 16 light receiving elements included in the light receiving element group PDG.
  • the element (PD22, 23, 32, 33) is selected.
  • the spectral characteristic setting unit 12 selects either the visible to infrared spectral characteristic or the infrared spectral characteristic as the spectral characteristic of the light receiving element selected by the light receiving element selecting unit 11. To do.
  • the received light amount calculation unit 13 see FIG.
  • the spectral characteristic setting unit 12 sets the visible to infrared spectral characteristic. While the infrared spectral characteristic is set by the unit 12, the magnitude of the photocurrent generated from the light receiving element is subtracted to calculate the amount of received light.
  • the optical sensor 1 is designed so that light enters the range indicated by the light spot S.
  • the light may be incident on the range indicated by the light spot Sb. That is, part of the light incident on the range indicated by the light spot Sb is a disturbance light and may cause the optical sensor 1 to malfunction.
  • the optical sensor 1 can suppress an adverse effect caused by the disturbing light in the illuminance measurement.
  • this principle will be described in detail.
  • the optical sensor 1 Normally, the center of gravity (incident center) of the intensity distribution of light (environmental light) incident from the outside of the optical sensor and the center of the light receiving area (light receiving center) into the area where the plurality of light receiving elements are arranged (light receiving area)
  • the optical sensor is designed to match.
  • the optical sensor 1 is designed so that light enters the range indicated by the light spot S shown in FIG.
  • each center may be shifted due to external force acting on the optical sensor or aging deterioration. For this reason, the optical sensor according to the related art may not be able to measure the illuminance of the environment where the optical sensor is placed as designed.
  • the incident center is expected to shift to a position moved in a random direction from the light receiving center, the expected incident center coincides with the light receiving center.
  • the light spot Sb is a part of the vicinity of the center of the region D even when the light is incident on the light spot Sb instead of the light spot S. It is expected to include a partial region Db.
  • the light receiving element selection unit 11 receives a part of the light received in the region Db near the center of the region D among the 16 light receiving elements included in the light receiving element group PDG.
  • the received light amount calculation unit 13 By selecting an element, that is, a light receiving element that is more likely to receive ambient light than other light receiving elements, the received light amount calculation unit 13 (see FIG. 1) The influence of deviation can be suppressed.
  • the optical sensor 1 adjusts the optical characteristics so as to actively receive ambient light by selecting some of the 16 light receiving elements arranged in the region D.
  • FIG. 8 is a graph showing the spectral characteristics of the light receiving element PD when the optical sensor 1 shown in FIG. 1 is used for illuminance measurement.
  • the horizontal axis indicates the wavelength of light incident on the light receiving element PD
  • the vertical axis indicates the amount of light in watts (W) and the photocurrent generated from the light receiving element PD in amperes (A). The ratio of both is shown.
  • W watts
  • A amperes
  • the ratio of both is shown.
  • the infrared spectral characteristic is subtracted by ⁇ times from the visible to infrared spectral characteristic, the spectral characteristic close to the visibility is obtained.
  • the value of ⁇ is selected so as to match the known visibility.
  • “Visibility” means the degree of brightness perceived by a person when the human eye receives light of the wavelength with respect to a wavelength included in a predetermined range.
  • the visual sensitivity takes a maximum value for the wavelength near the center of the visible light wavelength range (about 400 to 700 nm), and takes a smaller value for wavelengths closer to both ends of the range.
  • spectral characteristics close to visual sensitivity means that the spectral characteristics are close to the relationship between the wavelength of light received by the human eye and the degree of brightness that the person perceives visually.
  • the spectral characteristic setting unit 12 sets the visible to infrared spectral characteristic as the spectral characteristic of the light receiving element PD, the light receiving element is visible to infrared. A photocurrent corresponding to the amount of received light is generated. Further, while the spectral characteristic setting unit 12 sets the infrared spectral characteristic as the spectral characteristic of the light receiving element, the light receiving element generates a photocurrent corresponding to the amount of received infrared light.
  • the received light amount calculation unit 13 subtracts the magnitude of the photocurrent according to the amount of received light of infrared light from the magnitude of the photocurrent according to the amount of received light of visible to infrared light.
  • the magnitude of the photocurrent according to the amount of received visible light can be calculated.
  • the optical sensor 1 is suitable for illuminance measurement because it can realize spectral characteristics close to the visibility.
  • the optical sensor 1 can suppress an adverse effect caused by a shift in the incident center of ambient light and is suitable for illuminance measurement.
  • the optical sensor 1 is not limited to the configuration shown in FIG. 2, and the light receiving element PD may include three or more PN junctions having different spectral characteristics. In other words, the light receiving element PD may further include a PN junction other than the infrared light receiving PN junction PDir and the visible light receiving PN junction PDvis.
  • the switching unit SWS may switch the connection state between the PN junctions using three or more switches.
  • three or more PN junctions generate photocurrents corresponding to the amounts of three or more types of light that are included in the light received by the light receiving element PD and have different wavelengths.
  • the received light amount calculation unit 13 can receive a photocurrent corresponding to the amount of light of three or more types from the light receiving element PD.
  • the optical sensor 1 can suppress adverse effects caused by various kinds of light as disturbances in proximity detection and illuminance measurement.
  • the optical sensor 1 further includes a resin sealing portion 22 that seals the light receiving element group PDG.
  • the resin sealing portion 22 is located in a region on the substrate 21 where the light receiving element group PDG is disposed. You may have the lens (lens shape) 23 which condenses light.
  • the lens receives light received by the light sensor in a narrow area.
  • the lens allows the optical sensor to have high directivity with respect to the optical axis direction of the lens.
  • the focal point of the lens is matched with the area. In such a case, it is preferable that the relative positional relationship between the lens and the region where the light is collected is fixed.
  • the light received by the optical sensor 1 is condensed on the light receiving area by the lens 23 and the relative positional relationship between the lens 23 and the light receiving area is fixed, so that the light receiving area is narrowed. Even in this case, the light receiving element PD can accurately receive light.
  • FIG. 9 is a plan view showing a configuration of a main part of an optical sensor 1 according to another embodiment of the present invention.
  • the optical sensor 1 includes an analog-to-digital conversion unit (analog-to-digital conversion means) ADC that converts the magnitude of the photocurrent Ia generated from the light receiving element PD included in the region Da into a digital value ADCOUTa.
  • ADC analog-to-digital conversion unit
  • the controller 10a may be configured by adding an analog-digital converter ADC to the controller 10 (see FIG. 1).
  • the other structure of the optical sensor 1 is the same as that of the optical sensor 1 utilized for the proximity detection shown in FIG.
  • the analog-digital conversion unit ADC can convert the magnitude of the photocurrent Ia corresponding to the amount of light received by each light receiving element PD into a digital value ADCOUTa. That is, the optical sensor 1 can output a digital value representing the amount of received light that can be subjected to desired digital processing in proximity detection.
  • the photocurrent Ia is a photocurrent generated from the light receiving element PD while the infrared spectral characteristic is set by the spectral characteristic setting unit 12.
  • FIG. 10 is a plan view showing another configuration of the main part of the optical sensor 1 shown in FIG.
  • the optical sensor 1 further includes a plurality of analog-digital conversion units (analog-digital conversion means) ADCs that convert the magnitudes of the photocurrents Ib and Ic generated from the light receiving element PD into digital values. May be.
  • a controller 10b is configured by adding two analog-to-digital converters ADC to the controller 10 (see FIG. 1), and the received light amount calculator 13 (see FIG. 1) has a first analog signal.
  • the subtraction between the digital value ADCOUTb output from the digital conversion unit ADC and the digital value ⁇ ⁇ ADCOUTc obtained by multiplying the digital value ADCOUTc output from the second analog-digital conversion unit ADC by ⁇ by a multiplier (not shown) is performed. It may be.
  • the other structure of the optical sensor 1 is the same as that of the optical sensor 1 utilized for the illumination intensity measurement shown in FIG.
  • the magnitudes of the photocurrents Ib and Ic corresponding to the amount of light received by each light receiving element PD can be converted into digital values (ADCOUTb- ⁇ ⁇ ADCOUTc) by the analog-digital conversion unit ADC. That is, the optical sensor 1 can output a digital value representing the amount of received light that can be subjected to desired digital processing in illuminance measurement.
  • the photocurrent Ib is a photocurrent generated from the light receiving element PD while the visible to infrared spectral characteristics are set by the spectral characteristic setting unit 12, and the photocurrent Ic is red by the spectral characteristic setting unit 12. This is a photocurrent generated from the light receiving element PD while the external spectral characteristic is set.
  • FIG. 11 is a diagram illustrating a configuration according to a modification of the analog-digital conversion unit ADC illustrated in FIGS. 9 and 10.
  • the analog-digital conversion unit ADC includes a charging circuit (integrating circuit) 15, a discharging circuit 16, a comparison circuit 17, and a control circuit (output circuit) 18.
  • a charging circuit integrating circuit
  • a discharging circuit a comparison circuit
  • a control circuit output circuit
  • the charging circuit 15 includes an amplifier AMP1 constituting an integrator and a capacitor (integrating capacitor) C1. An amount of electric charge corresponding to the input current Iin is stored in the capacitor C1.
  • the discharge circuit 16 includes a power supply Vdd, a reference current source Iref that generates a reference current IREF for discharging the charge stored in the capacitor C1, and a switch SW2 for switching ON / OFF of discharge.
  • the comparison circuit 17 includes a comparator CMP1 and a switch SW1.
  • the comparator CMP1 compares the output voltage Vsig of the charging circuit 15 with the reference voltage Vref supplied by the reference voltage source V1, and outputs an output signal (pulse signal) comp.
  • the data conversion period in which the input current Iin is converted to the digital value ADCOUT is determined by turning on / off the switch SW1.
  • the switch SW1 when the switch SW1 is turned on, the reference voltage source V1 is connected to the charging circuit 15, the reference voltage Vref is supplied to the capacitor C1, and the capacitor C1 is charged.
  • the comparator CMP1 When the switch SW1 is turned off, the output voltage Vsig of the charging circuit 15 and the reference voltage Vref are compared by the comparator CMP1.
  • the comparison output signal comp is input to the control circuit as a binary pulse signal of “High” and “Low”.
  • An input current Iin that is input while the switch SW1 is OFF is converted to a digital value ADCOUT.
  • the control circuit 18 includes a flip-flop FF and a counter COUNT.
  • the output signal comp of the comparison circuit 17 is latched by the flip-flop FF.
  • the bit stream signal charge is input to the discharge circuit 16 and the counter COUNT, respectively.
  • the counter COUNT counts the number of LOW levels (the number of discharges) of the bit stream signal charge. That is, the counter COUNT counts active pulses. Further, the count result is output as a digital value ADCOUT which is an analog-digital conversion value corresponding to the input current Iin.
  • the switch SW2 of the discharge circuit 16 is turned ON / OFF based on the bit stream signal charge.
  • the switch SW2 of the discharge circuit 16 is turned on, electric charge is stored in the capacitor C1 of the charging circuit 15 by the discharge circuit 16.
  • the switch SW2 is turned off, the charge of the capacitor C1 of the charging circuit 15 is discharged according to the input current Iin.
  • FIG. 12 is a waveform diagram showing an operation of the analog-digital conversion unit ADC shown in FIG.
  • the switch SW2 when a high level signal is input to the switch SW2, the switch SW2 is turned off, and the charge stored in the capacitor C1 of the charging circuit 15 is discharged according to the input current Iin (precharge operation). As a result, the output voltage Vsig of the charging circuit 15 decreases.
  • the output voltage Vsig of the charging circuit 15 and the reference voltage Vref are set in the same manner, the output voltage Vsig of the charging circuit falls below the reference voltage Vref during this period.
  • the switch SW2 When a low level signal is input to the switch SW2, the switch SW2 is turned on, and the capacitor C1 of the charging circuit 15 is charged by the discharging circuit 16 with the electric charge. As a result, the output voltage Vsig of the charging circuit 15 increases. At some point, the output voltage Vsig of the charging circuit 15 exceeds the reference voltage Vref.
  • the output voltage Vsig of the charging circuit 15 and the reference voltage Vref are compared by the comparator CMP1, and when the output voltage Vsig of the charging circuit 15 exceeds the reference voltage Vref, a high level output signal comp is output from the comparator CMP1. .
  • the flip-flop FF latches the output signal comp, and in synchronization with the rise of the next clock signal clk, the high-level bit stream signal charge. Is output.
  • the switch SW2 When the high-level bit stream signal charge is input to the switch SW2, the switch SW2 is turned off, and the charge stored in the capacitor C1 of the charging circuit 15 is discharged. As a result, the output voltage Vsig of the charging circuit 15 decreases. At some point, the output voltage Vsig of the charging circuit 15 falls below the reference voltage Vref. When the output voltage Vsig of the charging circuit 15 falls below the reference voltage Vref, a low level output signal comp is output as an active pulse indicating that the output of the comparator CMP1 is at the active level. Note that the active pulse may be set to either the Low level or the High level, and can be appropriately selected depending on the operation logic of the circuit.
  • the flip-flop FF latches the output signal comp so that the control circuit 18 takes in the output signal comp, and the flip-flop FF A low-level bit stream signal charge is output in synchronization with the rise of the signal clk.
  • the switch SW2 When a low-level bit stream signal charge is input to the switch SW2, the switch SW2 is turned on.
  • the bit stream signal charge is a time-series arrangement of low level signals (active pulses), and the switch SW2 is turned on during the low level period (active pulse period).
  • the analog-digital conversion unit ADC repeats the above operation, and the counter COUNT counts the number of discharges count of the discharge circuit 16 during the period in which the switch SW1 is turned off, that is, the data conversion period t_conv. It becomes possible to output a digital value ADCOUT corresponding to the current Iin.
  • the amount of charge charged by the input current Iin in the data conversion period t_conv is, assuming that the period of the clock signal clk is t_clk.
  • the minimum resolution of the analog-digital conversion unit ADC is determined by (IREF ⁇ t_clk).
  • the integration type analog-to-digital conversion unit ADC can perform analog-to-digital conversion with a wide dynamic range and high resolution. Further, such an integral type analog-digital conversion unit ADC is suitable for an illuminance sensor or a proximity sensor.
  • the analog-to-digital conversion unit ADC uses the current output from each of the above-described sensors as the input current Iin and performs analog-to-digital conversion and uses a digital value, thereby providing a highly accurate color temperature with an inexpensive configuration.
  • the illuminance can be calculated.
  • the input voltage to the non-inverting input terminal of the amplifier AMP1 can be set to 0V.
  • the both-ends voltage (bias voltage) of the above-mentioned PN junction (PDir, PDvis) can be set to 0V. Therefore, it is possible to reduce the dark current of the PN junction, and it is possible to accurately measure even a low light amount. That is, measurement with low sensitivity can be performed accurately.
  • the optical sensor 1 can output a digital value representing the amount of received light that can be subjected to desired digital processing. Further, the optical sensor 1 can accurately measure the amount of received light with low sensitivity.
  • FIG. 13 is a waveform diagram of digital signals and the like output in proximity detection by the analog-to-digital conversion unit ADC shown in FIGS. 9 to 11, and (a) shows a case where the proximity of an object is detected, and (b) FIG. 5 is a diagram illustrating a case where non-adjacent objects are detected.
  • the configuration of the optical sensor 1 is the same as the configuration shown in FIG. Here, if the digital signal DOUT during the period when the light emitting element LED is driven is Data1, and the digital signal DOUT during the period when the light emitting element LED is not driven is Data2, the difference between the data (Data1-Data2) is close. It becomes data.
  • the proximity data (Data 1 -Data 2) exceeds the threshold Data_th of the control circuit, and thus is determined to be close.
  • the proximity data (Data 1 -Data 2) does not exceed the threshold Data_th of the control circuit, and is thus determined as non-proximity.
  • FIG. 14 is a block diagram showing a schematic configuration of a display device 5 according to another embodiment of the present invention.
  • the display device 5 includes the optical sensor 1, a backlight control unit 51, a backlight 52, and a liquid crystal panel 55.
  • the backlight 52 is a light source for irradiating light from the back surface of the liquid crystal panel 55 that displays a screen, and has, for example, a red LED, a green LED, and a blue LED.
  • the optical sensor 1 receives the ambient light of the display device 5 and measures the color component of the ambient light, and outputs a digital signal DOUT to the backlight control unit 51 as a measurement result.
  • the backlight control unit 51 calculates a color component and illuminance by calculating from the digital signal DOUT. Based on the calculated information, the brightness of the red LED, green LED, and blue LED of the backlight 52 is controlled to control the color of the backlight 52 according to the color component of the ambient light or The brightness can be controlled.
  • the backlight control unit 51 controls to increase the luminance of the backlight 52, and when the illuminance of the ambient light is small, the backlight control unit 51 decreases the luminance of the backlight 52. To control. Thereby, the power consumption of the backlight 52 can be suppressed, and the color of the liquid crystal panel 55 can be accurately controlled so as to correspond to the color adaptation of the eyes.
  • the display device 5 can accurately detect the proximity of the surrounding object by the optical sensor 1, the brightness of the backlight 52 can be controlled according to the proximity of the surrounding object.
  • a display device 5 is suitable for a mobile phone or a digital still camera including a display panel such as the liquid crystal panel 55, for example.
  • the signal output from the optical sensor 1 may be converted by the above-described analog-digital conversion unit ADC.
  • the backlight control unit 51 performs the backlight based on the converted output signal.
  • the brightness of the light 52 may be controlled.
  • the display device 5 may be applied to other products and used as a part of an application product (mobile phone, digital camera) 6.
  • the control block (especially the control units 10, 10a, 10b) of the optical sensor 1 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or a CPU (Central Processing Unit). And may be realized by software.
  • control units 10, 10 a, and 10 b include a CPU that executes instructions of a program that is software that realizes each function, and a ROM (Read that records the above program and various data so that the computer (or CPU) can read them. Only Memory) or a storage device (these are referred to as “recording media”), RAM (Random Access Memory) for expanding the program, and the like. And the objective of this invention is achieved when a computer (or CPU) reads the said program from the said recording medium and runs it.
  • a “non-temporary tangible medium” such as a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used.
  • the program may be supplied to the computer via an arbitrary transmission medium (such as a communication network or a broadcast wave) that can transmit the program.
  • a transmission medium such as a communication network or a broadcast wave
  • the present invention can also be realized in the form of a data signal embedded in a carrier wave in which the program is embodied by electronic transmission.
  • the optical sensor 1 is an optical sensor that has a substrate 21 and measures the amount of received light, and is a plurality of light receiving elements (on the substrate) that receive light and generate a photocurrent.
  • Light receiving element group PDG Light receiving element group PDG
  • light receiving element selecting means light receiving element selecting unit 11
  • spectral characteristics for setting the spectral characteristics of the plurality of light receiving elements, respectively.
  • the photocurrent generated from the light receiving element selected by the setting means (spectral characteristic setting unit 12) and the light receiving element selecting means and having the spectral characteristic set by the spectral characteristic setting means is waited, and the amount of received light is calculated.
  • a received light amount calculation means (received light amount calculator 13).
  • the method for measuring the amount of received light includes the substrate 21 and a plurality of light receiving elements (light receiving element group PDG) arranged on the substrate to receive light and generate a photocurrent.
  • a light receiving element arranged at a specific position on the substrate is selected by the light receiving element selecting unit, and light having a specific wavelength is received by the spectral characteristic setting unit.
  • the spectral characteristic of the light receiving element is set so that a larger photocurrent is generated than when light of other wavelengths is received.
  • the received light amount calculation means can receive a photocurrent corresponding to the light amount of light having a specific wavelength, which is light incident on a specific position on the substrate, from the light receiving element.
  • the received light amount calculation means can calculate the received light amount of the photosensor while suppressing the adverse effect of the light incident on the position that causes the disturbance or the light having the wavelength that causes the disturbance.
  • such an optical sensor can be used for proximity detection for detecting an object close to the optical sensor and for illuminance measurement for measuring the illuminance of the environment where the optical sensor is placed.
  • the “spectral characteristic of the light receiving element” means the relationship between the wavelength of light having a certain amount of light and the magnitude of the photocurrent generated by the light receiving element receiving the light.
  • “Setting the spectral characteristics of the light receiving element” means setting the magnitude of the photocurrent that the light receiving element receives and generates a certain amount of light with respect to a wavelength included in a predetermined range. Means.
  • the optical sensor 1 according to aspect 2 of the present invention further includes a light emitting element LED that emits at least infrared light in the above aspect 1, and the light receiving element selection unit includes the light receiving element on the substrate among the plurality of light receiving elements. Select a part of the light receiving elements (PD13, 14, 23, 24, 33, 34, 43, 44) arranged on the light emitting element side of the region D where the plurality of light receiving elements are arranged, and set the spectral characteristics
  • the means may set an infrared spectral characteristic as the spectral characteristic of the light receiving element selected by the light receiving element selecting means.
  • the light sensor reflects the light emitted from the light emitting element to the object and receives the reflected light by the light receiving element, thereby detecting that the object is close.
  • Such an optical sensor may be used by being incorporated in a housing such as a portable terminal.
  • the case reflected light emitted from the light emitting element and reflected by the casing enters the light receiving element, and the light receiving element receives the object reflected light emitted from the light emitting element and reflected by an object outside the casing.
  • a photocurrent similar to the photocurrent generated when the light enters the light source is generated.
  • the optical sensor cannot distinguish between the case reflected light and the object reflected light, and erroneously detects that the object is close even if it is not close to the optical sensor.
  • the light receiving element selection unit includes a part of the plurality of light receiving elements disposed on the light emitting element side of the region where the plurality of light receiving elements are disposed on the substrate, that is, another light receiving element Therefore, the light receiving amount calculation unit can suppress the influence of the case reflected light in the calculation of the amount of received light.
  • the optical sensor adjusts the optical characteristics so as to positively receive object reflected light by selecting some of the light receiving elements arranged in the light receiving region, It is possible to reduce the received light amount of the case reflected light that becomes noise in the measurement of the received light amount.
  • the spectral characteristic setting unit sets the infrared spectral characteristic as the spectral characteristic of the light receiving element selected by the light receiving element selecting unit. Therefore, the light receiving element suppresses generation of a photocurrent caused by visible light, and selectively receives infrared light emitted from the light emitting element to generate a photocurrent. Therefore, the received light amount calculation means can suppress the influence of visible light in calculating the received light amount. In this way, the optical sensor is suitable for proximity detection because it can suppress erroneous detection due to visible light.
  • the optical sensor can suppress adverse effects caused by the reflected light from the housing and is suitable for proximity detection.
  • the “infrared spectral characteristics” means that the magnitude of the photocurrent generated when the light receiving element receives a fixed amount of infrared light is light that the light receiving element is not the infrared light.
  • the light receiving element selection unit is configured such that, among the plurality of light receiving elements, the region D in which the plurality of light receiving elements on the substrate are arranged. A part of the light receiving elements (PD22, 23, 32, 33) arranged in the vicinity of the center is selected, and the spectral characteristic setting means has visible to red as the spectral characteristics of the light receiving elements selected by the light receiving element selecting means. Either the spectral characteristic of the outside or the spectral characteristic of infrared is selected, and the received light amount calculating means is configured to receive from the light receiving element while the visible to infrared spectral characteristics are set by the spectral characteristic setting means. Calculate the amount of received light by subtracting the magnitude of the photocurrent generated from the light receiving element while the infrared spectral characteristics are set by the spectral characteristic setting means from the magnitude of the generated photocurrent. Also good.
  • the optical sensor is designed to match.
  • each center may be shifted due to external force acting on the optical sensor or aging deterioration. For this reason, the optical sensor may not be able to measure the illuminance of the environment where the optical sensor is placed as designed.
  • the incident center is expected to shift to a position moved in a random direction from the light receiving center, the expected incident center coincides with the light receiving center.
  • the received light amount calculation means can suppress the influence of the deviation of the incident center in the calculation of the received light amount.
  • the optical sensor adjusts the optical characteristics so as to actively receive ambient light by selecting some of the light receiving elements arranged in the light receiving region, and receives the light. It is possible to reduce variation in sensitivity representing the amount of received light that is actually output as a measurement result by the optical sensor with respect to the amount of received light.
  • the spectral characteristic setting unit sets the visible to infrared spectral characteristic as the spectral characteristic of the light receiving element
  • the light receiving element generates a photocurrent corresponding to the amount of received visible to infrared light.
  • the spectral characteristic setting means sets the infrared spectral characteristic as the spectral characteristic of the light receiving element
  • the light receiving element generates a photocurrent corresponding to the amount of received infrared light.
  • the received light amount calculation means subtracts the magnitude of the photocurrent according to the amount of received infrared light from the magnitude of the photocurrent according to the amount of received visible to infrared light, thereby receiving visible light.
  • the magnitude of the photocurrent according to the quantity can be calculated.
  • the optical sensor is suitable for illuminance measurement because it can realize spectral characteristics close to the visibility.
  • the optical sensor can suppress adverse effects caused by the deviation of the incident center of the ambient light and is suitable for illuminance measurement.
  • visible to infrared spectral characteristics means that the magnitude of the photocurrent generated when the light receiving element receives visible to infrared light with a certain amount of light is visible when the light receiving element is the light with the certain amount of light. It means the relationship between the wavelength of light received by the light receiving element and the magnitude of the photocurrent to be generated, which is larger than the magnitude of the photocurrent that is received and generated by light that is not infrared light.
  • visible to infrared light means light included in visible light or infrared light.
  • “Visibility” means the degree of brightness that a person's eyes perceive when light of the wavelength is received by a person's eyes with respect to wavelengths within a predetermined range.
  • the visual sensitivity takes a maximum value for the wavelength near the center of the visible light wavelength range (about 400 to 700 nm), and takes a smaller value for wavelengths closer to both ends of the range.
  • spectral characteristics close to visual sensitivity means that the spectral characteristics are close to the relationship between the wavelength of light received by the human eye and the degree of brightness that the person perceives visually.
  • each light receiving element may include an infrared light receiving PN junction PDir having infrared spectral characteristics. .
  • the received light amount calculating means A photocurrent corresponding to the amount of light can be received from the light receiving element.
  • the optical sensor can suppress adverse effects caused by infrared light that becomes a disturbance in proximity detection and illuminance measurement.
  • each light receiving element may include a visible light receiving PN junction PDvis having visible spectral characteristics.
  • the PN junction for receiving visible light generates a photocurrent corresponding to the amount of visible light contained in the light received by the light receiving element, so that the received light amount calculation means corresponds to the amount of visible light.
  • the received photocurrent can be received from the light receiving element.
  • the optical sensor can suppress an adverse effect caused by visible light that is a disturbance in proximity detection and illuminance measurement.
  • “Visible spectral characteristics” refers to the magnitude of the photocurrent generated when a light receiving element receives a certain amount of visible light, and the light receiving element receives light that is a certain amount of light but not visible light. It means the relationship between the wavelength of light received by the light receiving element and the magnitude of the photocurrent, which is larger than the magnitude of the photocurrent to be generated.
  • each light receiving element may include three or more PN junctions having different spectral characteristics.
  • the three or more PN junctions generate light currents corresponding to the light amounts of three or more types of light that are included in the light received by the light receiving element and have different wavelengths.
  • the received light amount calculation means can receive a photocurrent corresponding to the amount of light of three or more types from the light receiving element.
  • the optical sensor can suppress adverse effects caused by various kinds of light as disturbances in proximity detection and illuminance measurement.
  • the optical sensor 1 according to Aspect 7 of the present invention further includes a resin sealing portion 22 that seals the plurality of light receiving elements in any one of the Aspects 1 to 6, and the resin sealing portion includes the above-described resin sealing portion.
  • the light received by the light sensor is condensed in a narrow area by a lens or the like.
  • the focal point of the lens is matched with the area. In such a case, it is preferable that the relative positional relationship between the lens and the region where the light is collected is fixed.
  • the light received by the optical sensor is focused on the light receiving region by the lens shape, and the relative positional relationship between the lens shape and the light receiving region is fixed, so the light receiving region is narrowed. Even in this case, the light receiving element can accurately receive light.
  • the optical sensor 1 according to aspect 8 of the present invention is the optical sensor 1 according to any one of the aspects 1 to 7, wherein analog-digital conversion means (analog-digital conversion unit ADC) for converting the magnitude of the photocurrent into a digital value is provided. Furthermore, you may provide.
  • analog-digital conversion means analog-digital conversion unit ADC
  • the magnitude of the photocurrent corresponding to the amount of light received by the light receiving element can be converted into a digital value by the analog-digital conversion means. That is, the optical sensor can output a digital value representing the amount of received light that can be subjected to desired digital processing.
  • the optical sensor 1 according to Aspect 9 of the present invention includes, in any one of the Aspects 1 to 7, an integration capacitor (capacitor C1) that stores charges according to the magnitude of the photocurrent, and the integration capacitor stores the integration capacitor.
  • An integration circuit (charging circuit 15) that outputs a voltage corresponding to the amount of charge and the output voltage Vsig of the integration circuit and the reference voltage Vref are compared with each other, and the comparison result is expressed as a binary pulse signal (output).
  • a comparator circuit 17 that outputs the signal as a signal comp
  • a flip-flop FF that takes the pulse signal in synchronization with the clock signal clk and outputs the bit stream signal charge
  • a counter COUNT that counts the active pulses of the bit stream signal.
  • an output circuit (control circuit 18) for outputting a count result by the counter as a digital value.
  • the total length of the active pulse period corresponds to the magnitude of the photocurrent.
  • the output pulse current of the output circuit is integrated (that is, averaged) by the integration circuit, so that a digital value indicating the magnitude of the photocurrent is obtained.
  • the photosensor can convert the magnitude of the photocurrent corresponding to the amount of light received by the light receiving element into a digital value.
  • the optical sensor can output a digital value representing the amount of received light that can be processed in a desired manner.
  • the integration circuit can set the input voltage to the non-inverting input terminal of the amplifier to 0 V when outputting a voltage corresponding to the amount of charge stored in the integration capacitor using the amplifier.
  • the bias voltage of the light receiving element becomes 0V, and the light receiving element can reduce the dark current compared to the case where the bias voltage is not 0V. That is, the optical sensor can accurately measure the received light amount even when the received light amount is low and the photocurrent generated from the light receiving element is small. In other words, the optical sensor can accurately measure the amount of received light with low sensitivity.
  • the optical sensor 1 is the light sensor 1 according to any one of the aspects 1 to 9 generated from the two light emitting elements arranged at different positions on the substrate and the plurality of light receiving elements.
  • the center of gravity calculating means for calculating the center of gravity of the intensity distribution of the light incident on the region where the plurality of light receiving elements are arranged on the substrate, and while the first light emitting element emits light
  • a comparing means for comparing a distance between the center of gravity calculated by the center of gravity calculating means and the center of gravity calculated by the center of gravity calculating means while the second light emitting element emits light with a predetermined threshold;
  • a signal output means for outputting a signal indicating that the amount of received light measured by the optical sensor may not be a correct value when the distance exceeds the threshold value in the comparison result of the comparison means; May be.
  • the light emitted from the two light emitting elements may be reflected by the housing and enter the light receiving region.
  • each case reflected light is incident on different areas of the light receiving area.
  • the center-of-gravity calculating unit calculates the incident center of each case reflected light, and the comparing unit compares the distance between the incident centers (distance between incident centers) with a predetermined threshold.
  • the optical sensor determines whether the case reflected light is incident on the light receiving area. Can be notified.
  • the optical sensor can notify the outside whether or not the measured amount of received light is a correct value.
  • the optical sensor since the optical sensor includes at least two light emitting elements, measurement of the amount of received light can be continued using another light emitting element even if one light emitting element is broken.
  • the number of light-emitting elements included in the optical sensor is not limited to two, and may be three or more.
  • a display device includes a liquid crystal panel 55 that displays a screen, a backlight 52 that irradiates light to the liquid crystal panel, a backlight control unit 51 that controls the luminance of the backlight, and the aspect described above. 1 to 9, and the backlight control unit may control the luminance of the backlight based on a signal output from the optical sensor.
  • the display device since the display device includes the optical sensor that can accurately detect the proximity of the surrounding object, the luminance of the backlight can be controlled according to the proximity of the surrounding object.
  • the display device since the display device includes an optical sensor that can accurately detect the color component (illuminance information) of the ambient light, the brightness of the screen can be accurately controlled according to the illuminance of the ambient light. .
  • the backlight control unit may control the luminance of the backlight based on the digital value.
  • the optical sensor according to each aspect of the present invention may be realized by a computer.
  • the optical sensor is realized by the computer by operating the computer as each unit included in the optical sensor.
  • a control program and a computer-readable recording medium on which the control program is recorded also fall within the scope of the present invention.
  • the present invention can also be used to control the brightness of a backlight provided in a mobile phone or a digital camera.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Computer Hardware Design (AREA)
  • Theoretical Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)

Abstract

Selon la présente invention, afin de proposer un capteur optique dans lequel des effets négatifs dus à une lumière considérée comme une perturbation peuvent être supprimés à proximité d'une détection et d'une mesure d'éclairage, un capteur (1) optique comprend: un groupe (PDG) d'éléments de réception de lumière comprenant une pluralité d'éléments de réception de lumière, qui reçoivent une lumière et génèrent un photo-courant ; une unité (11) de sélection d'élément de réception de lumière qui sélectionne un élément de réception de lumière ; une unité (12) de réglage de caractéristique spectroscopique qui règle des caractéristiques spectroscopiques des éléments de réception de lumière ; et une unité (13) de calcul de quantité de réception de lumière, qui reçoit le photo-courant généré au moyen de l'élément de réception de lumière, et calcule une quantité de réception de lumière.
PCT/JP2014/055606 2013-05-22 2014-03-05 Capteur optique et appareil d'affichage Ceased WO2014188756A1 (fr)

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JP2013108345 2013-05-22
JP2013-108345 2013-05-22

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WO2016167259A1 (fr) * 2015-04-15 2016-10-20 シャープ株式会社 Circuit de capteur
JP2017005428A (ja) * 2015-06-08 2017-01-05 ローム株式会社 近接センサ
WO2017094278A1 (fr) * 2015-11-30 2017-06-08 シャープ株式会社 Photodétecteur
CN113407068A (zh) * 2020-03-16 2021-09-17 罗姆股份有限公司 受光ic、非接触式传感器及电子设备
WO2023042304A1 (fr) * 2021-09-15 2023-03-23 日本電気株式会社 Dispositif de commande de réception, procédé de commande de réception et support d'enregistrement
DE112019005636B4 (de) * 2018-11-12 2025-04-30 Sony Semiconductor Solutions Corporation Optisches modul und abstandsmessvorrichtung

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JPWO2016167259A1 (ja) * 2015-04-15 2017-11-24 シャープ株式会社 センサ回路
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DE112019005636B4 (de) * 2018-11-12 2025-04-30 Sony Semiconductor Solutions Corporation Optisches modul und abstandsmessvorrichtung
CN113407068A (zh) * 2020-03-16 2021-09-17 罗姆股份有限公司 受光ic、非接触式传感器及电子设备
CN113407068B (zh) * 2020-03-16 2023-12-05 罗姆股份有限公司 受光ic、非接触式传感器及电子设备
WO2023042304A1 (fr) * 2021-09-15 2023-03-23 日本電気株式会社 Dispositif de commande de réception, procédé de commande de réception et support d'enregistrement
JPWO2023042304A1 (fr) * 2021-09-15 2023-03-23
JP7673815B2 (ja) 2021-09-15 2025-05-09 日本電気株式会社 受信制御装置、受光装置、通信装置、受信制御方法、およびプログラム

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