JP6523014B2 - Proximity sensor device - Google Patents

Description

  The present invention relates to a proximity sensor device that detects proximity of a detection object such as a human finger by light such as infrared light, and in particular, to activate screen display when a human finger or the like approaches, an icon on the display surface, touch button The present invention relates to a proximity sensor device that is applied to a display device or the like that performs display driving such as displaying a hidden display unit such as, or switching a still image display to a moving image display.

  Conventionally, for example, in a liquid crystal display (LCD) used for a navigation system of a car, a tablet terminal, a smartphone, etc., a finger of a person is close to a display screen to operate a touch panel or the like provided on the LCD. In some cases, a proximity sensor device is provided to activate the screen display, display a hidden display unit such as an icon or touch button on the display surface, or switch the still image display to a moving image display. is there. As this proximity sensor device, there are a capacitance proximity sensor device, an inductance proximity sensor device, an infrared proximity sensor device, and the like.

One example of the LCD provided with the infrared proximity sensor device is shown in FIGS. 6 (a) and 6 (b). The LCDs shown in FIGS. 6 (a) and 6 (b) have the configuration previously proposed by the applicant of the present invention (Japanese Patent Application No. 2014-57418).
FIG. 6A is a front view of the LCD, and FIG. 6B is a cross-sectional view of the LCD. This LCD has a liquid crystal display panel 22 provided at the left and right ends with an infrared detection unit 26 for detecting an object to be detected 29 such as a finger of a person approaching the display surface 22a, a glass covering the display surface 22a and the infrared detection unit 26 A transparent member 21 made of a plate, a plastic plate or the like, a frame 23 made of a plastic having an opening for inserting the liquid crystal display panel 22, a plastic provided on the opposite display surface 22b side of the liquid crystal display panel 22 And a protection member 25 consisting of The infrared detection unit 26 includes the infrared light receiving element 26b and the infrared light emitting element 26a having a larger number than that, and is inclined so that the infrared light emitting element 26a is directed to the normal h direction of the central portion of the display surface 22a. Is installed. With this configuration, there is no occurrence of EMI (Electromagnetic Interference) in the surrounding electronic parts, circuit wiring, etc., and conversely, there is no EMI from the surrounding electronic parts, circuit wiring etc., and the display surface 22a of the liquid crystal display panel 22. The object to be detected 29 such as the hand of a person or the like who is laterally separated from the installation position of the infrared detection unit 26 can be favorably detected.

  The infrared detection unit 26 is covered by the transparent member 21. However, the portion covering the infrared detection unit 26 of the transparent member 21 is, for example, a light shielding layer of a color shade such as black which transmits infrared light but not visible light. A member is provided, and a portion corresponding to the display surface 22a of the transparent member 1 is transparent for transmitting visible light. Further, the infrared detection unit 26 is installed, for example, on the overhang member 28 attached to the end of the non-display surface 22 b of the liquid crystal display panel 22 by means of adhesion with an adhesive, screwing, or the like. The overhang member 28 is attached to the opposite display surface 22 b of the liquid crystal display panel 22 by a double-sided adhesive tape such as a transparent adhesive or a highly transparent adhesive transfer tape (Optically Clear Adhesive Tape (OCA)). Further, in the overhang member 28, for example, a portion projecting from the opposite display surface 22 b of the liquid crystal display panel 22 is inclined toward the central portion of the display surface 22 a, and the infrared detection unit 26 is installed in that portion . Further, as shown in FIG. 6B, the transparent member 21, the liquid crystal display panel 22, and the frame 23 having an opening for fitting the liquid crystal display panel 22 from the viewer side, the backlight 24, and the backlight 24 are fixed. A metal frame 24a made of aluminum or the like, and a protection member 25 are disposed. The metal frame 24 a is fitted to the frame 23 and fixed by means such as screwing, and the protective member 25 is fixed to the frame 23 by means such as screwing. Reference numeral 27 denotes a conductor plate for grounding or the like, which is provided on the main surface of the backlight 24 opposite to the liquid crystal display panel 22 and made of aluminum (Al) or the like.

  The radiation direction of the infrared light of the infrared light emitting element 26a is a predetermined angle range including an angle θ of 45 ° between the radiation axis (radial central axis) Ac and the display surface 22a and the outer major surface of the transparent member 21. It is configured to be able to effectively detect an object to be detected 29 such as a hand of a person who is laterally separated from the installation position of the infrared detection unit 26 at a certain distance (about 10 cm) from the central part of the display surface 22a There is.

  Further, as an example of a conventional detection device using light in the near-infrared wavelength range, there is one disclosed in Patent Document 1, and an object such as a human face is detected using light in the near-infrared wavelength range A part discrimination apparatus and a sex determination apparatus of an object to be discriminated have been proposed. This device emits light in the near-infrared wavelength range to the object and illuminates with light in the near-infrared wavelength range the pixel value of the image of the object taken and the state in which the light is not illuminated By calculating the difference with the pixel value of the image of the target object, the influence of disturbance light is eliminated. Then, based on the calculated difference, each region of the object, for example, the driver's skin, hair, eyeball, is discriminated to detect the face area, and a part of the face area, for example, a pixel of the eyebrow between the nose and the mouth The occupancy rate of the pixel having the value is determined, and the gender is determined from the result. That is, by calculating the difference between the irradiation detection value obtained when the object is illuminated with light in the near infrared wavelength range and the non-irradiation detection value obtained when the object is not irradiating light, It is intended to remove the influence of ambient light and other disturbance light.

JP, 2008-27242, A

  However, by calculating the difference between the detection value at the time of irradiation and the detection value at the time of non-irradiation, in a detection device of a method of removing the influence of disturbance light such as ambient light, a very bright environment such as direct light of sunlight When light enters the infrared light receiving element and is received, even if the reflected infrared light from the detection object is also received at the same time, the reflected infrared light is only about several% of the intensity of the infrared light emitted from the infrared light emitting element 26a. The detection signal of the reflected infrared light may be buried in the environment detection signal of the ambient light, which may make it difficult to detect the detection subject.

  Therefore, in order to reliably detect the reflected infrared radiation from the detection target 29, a detection signal obtained by converting the reflected infrared radiation into an electrical signal by the infrared light receiving element 26b, and a reference signal (base A method of calculating the difference with the signal) and comparing the difference with a predetermined threshold may be employed. However, even when there is no detected object such as a human finger in front of the display device, environmental light including direct light such as sunlight is received by the infrared light receiving element 26b. In the case of bright light such as light, as shown in FIG. 7A, a large detection signal 31 similar to that in the case of detecting the detection target 29 is obtained. When a difference ΔS between the detection signal 31 and a reference signal 32 obtained by delaying the detection signal 31 by a predetermined time is taken, an erroneous detection as if the detection target 29 was detected occurred. Similarly, even if there is no detected object 29 such as a human finger in front of the display, if the ambient light is slightly dark, such as repeating light and dark, for example, if the shade is moved during fine weather For example, a pulsating detection signal 33 as shown in FIG. 7 (b) is obtained. When a difference ΔS between the detection signal 33 and a reference signal 34 obtained by delaying the detection signal 33 by a predetermined time is taken, an erroneous detection as if the detection target 29 was detected occurred.

  Therefore, the present invention has been completed in view of the above-mentioned conventional problems, and its object is to detect a false detection of an object even when environmental light including infrared rays of sunlight is received. It is providing the proximity sensor device which can be prevented.

In the proximity sensor device of the present invention, a light detection unit having a light emitting element and a light receiving element, a detection signal processing unit for detecting the proximity of the detection object based on a detection signal of the light receiving element, and the light emitting element emitting light A first detection state in which the light receiving element is in a light receiving state, and a second detection state in which the light receiving element is in a light receiving state for detecting environmental light while the light emitting element is in a non-light emitting state; A detection control unit that controls to repeat alternately and an illuminance sensor are provided, and the detection signal processing unit is configured to delay the detection signal and the detection signal for a predetermined time in the first detection state. The proximity or non-proximity of the object to be detected is detected by comparing the difference with the reference signal with the first threshold, and the ambient light is detected as the light receiving element and the illuminance sensor in the second detection state. Therefore, it is a proximity sensor device which acquires the 1st environmental light signal detected by the light receiving element when detecting, and the 2nd environmental light signal detected by the illumination intensity sensor, and the detection signal processing unit further comprises: When the ambient light signal of No. 2 is less than or equal to the second threshold, the first variation component of the first ambient light signal is superimposed on the reference signal in the first detection state, and the difference from the detection signal is calculated. And detecting the proximity or non-proximity of the detection target by comparing the difference with the first threshold, and the second environment light signal exceeds the second threshold, the first environment A third ambient light signal in which a signal of a predetermined intensity is added to the light signal is generated, and a second fluctuation component of the third ambient light signal is superimposed on the reference signal in the first detection state to perform the detection. Take the difference from the signal, the difference Wherein by comparing the said first threshold value is configured to detect the proximity or non-proximity detection object.

  In the proximity sensor device of the present invention, preferably, the signal of the predetermined intensity is 5% to 100% of the intensity of the second ambient light signal.

  In the proximity sensor device of the present invention, preferably, the reference signal is a delay signal formed by delaying the detection signal by 100 msec to 500 msec.

  In the proximity sensor device of the present invention, preferably, the first fluctuation component is acquired when the first ambient light signal and the ambient light are not detected by the light receiving element in the second detection state. The second variation component is a second difference signal between the third ambient light signal and the non-detection signal.

  In the proximity sensor device of the present invention, preferably, when the ambient light contains an infrared ray, the light emitting element emits an infrared ray, and the light receiving element detects an infrared ray.

In the proximity sensor device of the present invention, a light detection unit having a light emitting element and a light receiving element, a detection signal processing unit for detecting proximity of an object to be detected based on a detection signal of the light receiving element, Control is performed so that the first detection state in which the light receiving element is in the light receiving state and the second detection state in which the light receiving element is in the light receiving state in order to detect environmental light while alternately emitting light. Detection signal control unit and an illuminance sensor, and the detection signal processing unit is configured to detect a difference between a detection signal and a reference signal formed by delaying the detection signal for a predetermined time in the first detection state and a first threshold value. And detecting the proximity or non-proximity of the detection object, and detecting the ambient light by the light receiving element and the illuminance sensor in the second detection state, the first ambient light signal detected by the light receiving element And a proximity sensor device that acquires a second ambient light signal detected by the illumination sensor, and the detection signal processing unit further detects the first ambient light when the second ambient light signal is less than or equal to a second threshold. The first fluctuation component of the signal is superimposed on the reference signal in the first detection state, the difference from the detection signal is taken, and the proximity or non-proximity of the detection subject is determined by comparing the difference with the first threshold. If the second ambient light signal exceeds the second threshold, a third ambient light signal is generated by adding a signal of a predetermined intensity to the first ambient light signal, and the third ambient light signal is generated. A configuration for detecting proximity or non-proximity of an object to be detected by superimposing the two fluctuation components on the reference signal in the first detection state, taking the difference from the detection signal, and comparing the difference with the first threshold. Therefore, the following effects can be obtained. That is, in the second detection state, since the light emitting element is in the non-emission state, the detection signal should not be obtained whether the detection object is present or absent in the detectable region space, When ambient light is detected in the second detection state, an ambient light signal is generated in the first and second detection states as an erroneous signal as if the object to be detected was detected. Then, using the illuminance sensor, if the illuminance is less than a predetermined reference, that is, if the second ambient light signal detected by the illuminance sensor is less than or equal to the second threshold, the first of the first ambient light signal When the fluctuation component of is superimposed on the reference signal in the first detection state and the difference from the detection signal is taken, the difference becomes smaller than the first threshold, so that the influence of the ambient light signal can be eliminated. When the illuminance exceeds a predetermined reference, that is, when the second ambient light signal detected by the illuminance sensor exceeds the second threshold, a third signal obtained by adding a signal of a predetermined intensity to the first ambient light signal When the ambient light signal is generated, and the second fluctuation component of the third ambient light signal is superimposed on the reference signal in the first detection state and the difference from the detection signal is taken, the difference is approximately 0 level or less As a result, the influence of the ambient light signal can be reliably eliminated.

  The proximity sensor device of the present invention is a third environment in which the signal of the predetermined intensity is added to the first ambient light signal when the signal of the predetermined intensity is 5% to 100% of the intensity of the second ambient light signal. When the light signal is generated and the second fluctuation component of the third ambient light signal is superimposed on the reference signal in the first detection state and the difference with the detection signal is taken, the difference is made to be approximately 0 level or less You can do it for sure.

  Further, in the proximity sensor device of the present invention, when the reference signal is a delay signal formed by delaying the detection signal by 100 msec to 500 msec, the proximity of the detection subject is detected by the difference between the detection signal and the reference signal and the first threshold. It is suitable for

  Further, in the proximity sensor device of the present invention, the first fluctuation component may be a first ambient light signal and a non-detection signal obtained when the ambient light is not detected by the light receiving element in the second detection state. If the difference signal is 1 and the second variation component is the second difference signal between the third ambient light signal and the non-detection signal, the first variation component and the second variation component can be reliably obtained. It can be extracted.

  In the proximity sensor device of the present invention, the light emitting element emits infrared light when ambient light contains infrared light, and the light receiving element detects infrared light, thereby eliminating the influence of sunlight including infrared light and the like. It is possible to prevent false detection of That is, the proximity sensor device can detect a human hand or the like that is a good reflector of infrared light, and can eliminate the influence of sunlight, illumination light and the like that cause the largest environmental light signal.

1 (a) and 1 (b) show an example of the embodiment of the proximity sensor device of the present invention, and FIG. 1 (a) is a block diagram of a basic configuration of the proximity sensor device, and FIG. It is a timing chart which shows the light emission timing of the light emitting element in a unit, and the light reception timing of a light receiving element. FIG. 2 shows another example of the embodiment of the proximity sensor device of the present invention, and is a timing chart showing the light emission timing of the light emitting element and the light reception timing of the light receiving element for two light detection units. FIGS. 3 (a) to 3 (c) show another example of the embodiment of the proximity sensor device of the present invention, and FIG. 3 (a) shows the difference between the detection signal and the reference signal in the first detection state. (B) is a graph showing the second fluctuation component of the third ambient light signal detected in the second detection state, and (c) is a graph showing the second fluctuation component of the third ambient light signal. It is a graph which shows superimposing on the reference signal in a 1st detection state, and taking a difference with a detection signal. 4 (a) to 4 (c) show another example of the embodiment of the proximity sensor device of the present invention, and (a) shows the difference between the detection signal and the reference signal in the first detection state. (B) is a graph showing the first variation of the first ambient light signal detected in the second detection state, (c) is a standard for the first fluctuation component in the first detection state It is a graph which shows superimposing on a signal and taking a difference with a detection signal. 5 (a) to 5 (c) show another example of the embodiment of the proximity sensor device of the present invention, and (a) shows the difference between the detection signal and the reference signal in the first detection state. (B) is a graph showing the first fluctuation component of the first ambient light signal detected in the second detection state, and (c) is a graph showing the first fluctuation component as the reference in the first detection state It is a graph which shows superimposing on a signal and taking a difference with a detection signal. 6 (a) and 6 (b) show a liquid crystal display device provided with a conventional infrared proximity sensor device, wherein (a) is a front view of the liquid crystal display device, and (b) is a sectional view of the liquid crystal display device. It is. FIGS. 7A and 7B show detection signals obtained by the conventional infrared proximity sensor device, and FIG. 7A shows the detection signal and the reference signal when bright ambient light is received by the infrared light receiving element. FIG. 8B is a graph showing that the difference between the detection signal and the reference signal is taken when the ambient light that repeats the light and dark by the infrared light receiving element is received.

  Hereinafter, an embodiment of a proximity sensor device of the present invention will be described with reference to the drawings. However, each drawing referred to below shows main constituent members and the like of the proximity sensor device of the present invention. Therefore, the proximity sensor device of the present invention may be provided with known components such as a circuit board, a wiring conductor, a control IC, an LSI, etc. which are not shown in the figure.

  1 to 5 show various examples of the embodiment of the proximity sensor device of the present invention, and as shown in these figures, the proximity sensor device of the present invention comprises the light emitting element 2 and the light receiving element 3. A detection signal processing unit that detects the proximity of the detection subject 4 based on the detection signals of the light detection unit 1 and the light receiving element 3 that receives the reflected light of the detection subject 4 that reflects the light emitted from the light emitting element 2 5 and a first detection state in which the light emitting element 2 is in a light emitting state and the light receiving element 3 is in a light receiving state, and in order to detect environmental light while the light emitting element 2 is in a non light emitting state The detection control unit 6 performs control so as to alternately repeat the second detection state, which is the second detection state, and the illuminance sensor 8. The detection signal processing unit 5 detects the detection signal 11 (the first detection state) 13) difference between reference signal 12 (14) When the proximity or non-proximity of the detection subject 4 is detected by comparing ΔS1 with the first threshold, and the ambient light 7 is detected by the light reception element 3 and the illuminance sensor 8 in the second detection state, the light reception element 3 A proximity sensor device for acquiring a first ambient light signal detected by the second ambient light signal detected by the illumination sensor and the second ambient light signal detected by the illumination sensor, and the detection signal processing unit 5 further includes a second threshold for the second ambient light signal. If not, the first variation component 13a of the first ambient light signal is superimposed on the reference signal 14 in the first detection state, and the difference ΔS2 with the detection signal 13 is taken, and the difference ΔS2 and the first threshold To detect the proximity or non-proximity of the detection subject 4 and compare the second ambient light signal with the second threshold, a signal 11b having a predetermined intensity added to the first ambient light signal. Generate 3 ambient light signals, By superimposing the second fluctuation component 11c of the ambient light signal No. 3 on the reference signal 12 in the first detection state, taking the difference ΔS3 with the detection signal 11, and comparing the difference ΔS3 with the first threshold value The configuration is such that proximity or non-proximity of the detection subject 4 is detected. With this configuration, the following effects can be obtained. That is, in the second detection state, since the light emitting element 2 is in the non-light emitting state, the detection signal 11 (13) can be obtained regardless of whether the object 4 is present or not in the detectable region space. Although it should not be, when ambient light 7 is received in the second detection state, the ambient light signal as a false signal as if the detected object 4 was detected is in the first and second detection states. Occur. Then, when the illuminance is equal to or less than a predetermined reference by using the illuminance sensor 8, that is, when the second ambient light signal detected by the illuminance sensor 8 is equal to or less than the second threshold, When the first fluctuation component 13a is superimposed on the reference signal 14 in the first detection state and the difference ΔS2 with the detection signal 13 is taken, the difference ΔS2 becomes smaller than the first threshold, so the influence of the ambient light signal Can be eliminated. In addition, when the illuminance exceeds a predetermined reference, that is, when the second ambient light signal detected by the illuminance sensor 8 exceeds the second threshold, a signal 11b having a predetermined intensity added to the first ambient light signal When an ambient light signal of No. 3 is generated and the second variation component 11c of the third ambient light signal is superimposed on the reference signal 12 in the first detection state and the difference .DELTA.S3 with the detection signal 11 is taken, the difference Since .DELTA.S3 can be reduced to about 0 level or less, the influence of the ambient light signal can be reliably eliminated.

  In the proximity sensor device of the present invention, the ambient light 7 is not light emitted from the light emitting element 2 but light detected as an ambient light signal which is a noise signal from the ambient environment of the proximity sensor device to the light receiving element 3. The ambient light 7 may be any light that can be detected by the light receiving element 3 and, for example, light with a wavelength of about 400 nm to about 750 nm for visible light and a wavelength of about 750 nm to about 1400 nm for infrared light It is infrared rays etc. Further, the ambient light 7 may include light of various wavelengths and frequencies such as ultraviolet light, visible light and infrared light, among which a proximity sensor device for detecting infrared light by the light receiving element 3 or a visible light receiving element As a proximity sensor device etc. which detect by 3, various detection forms can be taken.

  In the proximity sensor device of the present invention, the signal 11b of the predetermined intensity is preferably 5% to 100% of the intensity of the second ambient light signal. In this case, a third ambient light signal in which a signal 11b of a predetermined intensity is added to the first ambient light signal is generated, and the second variation component 11c of the third ambient light signal is used as a reference in the first detection state. If the difference ΔS3 between the reference signal 12a superimposed on the signal 12 and the detection signal 11 is taken, it is possible to ensure that the difference ΔS3 is about 0 level or less. When the intensity of the signal 11b exceeds the second ambient light signal 100%, the difference ΔS3 tends to be negative, so it is not always necessary to set it so as to exceed 100%.

  In the proximity sensor device of the present invention, the light emitting element 2 comprises an infrared light emitting diode (IR-LED) or the like, and the light receiving element 3 comprises a photodiode (PD) or the like. The light emitting element 2 has a driving current of, for example, 200 mA at the time of light emission and a driving current of at the time of non-light emission of, for example, 0 mA. As shown in FIG. 1B, the light emitting element 2 is driven at 200 mA in the first detection state, and the light emitting element 2 is driven at 0 mA in the second detection state. The light emission period and the non-light emission period of the light emitting element 2 are respectively set to about 8 msec (milliseconds). The light receiving period of the light receiving element 3 is also set to about 8 msec in synchronization with the light emitting period and the non-light emitting period of the light emitting element 2. Further, a reference signal (base signal) 12 (14) consisting of a delay signal obtained by delaying the detection signal 11 (13) for a predetermined time is preferably generated by delaying the detection signal 11 (13) by about 100 msec to 500 msec. Ru. In this case, the time for which the human hand approaches the proximity area is about 100 msec to 500 msec, which corresponds to the rising part of the detection signal 11, and the detection signal 11 is about 100 msec to 500 msec for the rising part. When the differences ΔS1 to ΔS3 between the reference signal 12 and the reference signal 12 are taken, the differences ΔS1 to ΔS3 can be increased. Further, since the signal from the rising portion of the detection signal 11 often lasts for a long time when the human hand approaches the proximity region, there is no change like the rising portion or the signal tends to be small. More preferably, 200 msec to 300 msec are preferable. In addition, the difference ΔS1 to ΔS3 between the detection signal 11 (13) and the reference signal 12 (14) and the first threshold value are suitable for detecting the proximity of the object 4 to be detected. That is, when the detection target 4 is near the detection limit, for example, in the case of the LCD shown in FIG. 6, the difference .DELTA.S1 when it is about 10 cm away from the outer surface of the transparent member 21 in the direction perpendicular thereto. The signal level can be set to be approximately equal to the first threshold value ΔS3.

  Further, the differences ΔS1 to ΔS3 are always taken, and it is determined that the detection subject 4 exists in the detectable area space at the moment when it exceeds the first threshold.

  Further, in the proximity sensor device of the present invention, the first fluctuation component 11 a is a non-detection signal obtained when the light receiving element 3 does not detect the first ambient light signal and the ambient light 7 in the second detection state. Preferably, the second variation component 11c is a second difference signal between the third ambient light signal and the non-detection signal. In this case, the first fluctuation component 11a and the second fluctuation component 11c can be reliably extracted.

  The first detection state is for detecting the detection subject 4, and when the detection subject 4 does not exist in the detectable area space and there is no ambient light 7 (case 1), the light receiving element 3 Since no light is received, a detection signal and an ambient light signal can not be obtained. When the detection subject 4 is present in the detectable area space and there is no ambient light 7 (case 2), the reflected light of the detection subject 4 is received by the light receiving element 3 to obtain a detection signal. When the detection subject 4 does not exist in the detectable area space and there is ambient light 7 (case 3), the light receiving element 3 receives the ambient light 7 and an ambient light signal is obtained. Further, when the detection subject 4 is present in the detectable area space and there is the ambient light 7 (case 4), a detection signal and an ambient light signal by the reflected light of the detection subject 4 can be obtained.

  The second detection state is for detecting (sampling) an ambient light signal, and it does not matter whether the object 4 is present in the detectable area space. When the ambient light 7 is not present (cases 1 and 2), the ambient light signal can not be obtained, and a signal of about 0 level or less can be obtained. When the ambient light 7 is present (cases 3 and 4), an ambient light signal is obtained.

  In Case 1, there is no detection signal 11 in the first detection state shown in FIG. 3A, and there is no fluctuation component 11a of the ambient light signal in the second detection state shown in FIG. 3B. It can be specified that the detection subject 4 does not exist in the detectable area space.

  In Case 2, the detection signal 11 in the first detection state shown in FIG. 3A is present, and there is no fluctuation component 11a of the ambient light signal in the second detection state shown in FIG. 3B. A signal level ΔS1 larger than the first threshold shown in FIG. 3A is obtained, and the presence of the detection subject 4 in the detectable region space can be identified.

  In the case 3, when the ambient light 7 is bright light such as direct light of sunlight, a first ambient light signal similar to the detection signal 11 in the first detection state shown in FIG. 3A. Is obtained. Also, in this case, the case corresponds to the case where the illuminance detected by the illuminance sensor 8 exceeds a predetermined reference, that is, the case where the second ambient light signal detected by the illuminance sensor 8 exceeds the second threshold. Note that the second threshold is set to, for example, a signal strength that is greater than one and twenty times lower than the first threshold. Then, a third ambient light signal is generated by adding a signal 11b of a predetermined intensity (for example, about 10% of the signal intensity of the second ambient light signal) to the first ambient light signal, as shown in FIG. As shown, the second fluctuation component 11c obtained by subtracting the non-detection signal from the third ambient light signal is superimposed on the reference signal 12 in the first detection state to obtain a difference ΔS3 with the detection signal 11. As a result, as shown in FIG. 3C, the difference .DELTA.S3 can be made approximately equal to or less than 0 level, so that the influence of the ambient light signal can be reliably eliminated. And it can specify that the to-be-detected body 4 does not exist in a detectable area | region space.

  In the case 3, when the ambient light 7 repeats light and dark, a first ambient light signal similar to the pulsating detection signal 13 in the first detection state shown in FIG. 4A is obtained. Further, in this case, the case corresponds to the case where the illuminance detected by the illuminance sensor 8 is less than a predetermined reference, ie, the case where the second ambient light signal detected by the illuminance sensor 8 is less than the second threshold. Then, as shown in FIG. 4B, the first fluctuation component 13a obtained by subtracting the non-detection signal from the pulsating first ambient light signal is superimposed on the reference signal 14 in the first detection state and detected. The difference ΔS2 with the signal 13 is taken. As a result, as shown in FIG. 4C, since the difference ΔS2 can be made smaller than the first threshold value, the influence of the ambient light signal can be reliably eliminated. And it can specify that the to-be-detected body 4 does not exist in a detectable area | region space.

  In case 4, when the ambient light 7 is bright, a detection signal obtained by adding a first ambient light signal having a similar waveform to the detection signal 11 in the first detection state shown in FIG. 3A is obtained. Then, as shown in FIG. 3B, a third ambient light signal obtained by adding a signal 11b of a predetermined intensity (for example, about 10% of the signal intensity of the second ambient light signal) to the first ambient light signal is obtained. A second fluctuation component 11c generated by subtracting the non-detection signal from the third ambient light signal is superimposed on the reference signal 12 in the first detection state to obtain a difference ΔS3 with the detection signal 11. Since the difference ΔS3 results in a signal level larger than the first threshold value, it can be identified that the object 4 is present in the detectable area space.

  Further, in the case 4, when the ambient light 7 repeats light and dark, the pulsating first ambient light signal shown in FIG. 4A is added to the detection signal 11 in the first detection state shown in FIG. The added detection signal, that is, the detection signal 15 shown in FIG. 5A is obtained. Further, there is a first fluctuation component 15a of the pulsating type first ambient light signal in the second detection state shown in FIG. 5 (b). Then, as shown in FIG. 5C, the detection signal 11 shown in FIG. 3C is obtained by adding the first ambient light signal of the pulsating type shown in FIG. The difference .DELTA.S2 with the reference signal 16a obtained by superimposing the first fluctuation component 15a of the pulsating first ambient light signal shown in FIG. Since this difference ΔS2 results in a signal level larger than the first threshold value, it can be specified that the detection subject 4 is present in the detectable area space.

  The embodiments of the present invention are summarized below. First, the detection signal of the light receiving element 3 in the first detection state is PS (1), the detection signal of the light receiving element 3 in the second detection state is PS (2), and fluctuation components of PS (2) (first environment A first fluctuation component) obtained by subtracting the non-detection signal from the light signal is ΔPS (2), and the reference signal is BS (1). For example, ΔPS (2) can be obtained by taking an average value of PS (2) in a certain period and taking a difference between the average value of a certain period and the average value of the previous period. Then, a noise superimposed reference signal BSP (2) is generated by superposing ΔPS (2) on BS (1), and a difference ΔS2 between PS (1) and BSP (2) is obtained. At this time, when the second ambient light signal detected by the illuminance sensor is equal to or less than the second threshold, the difference ΔS2 = PS (1) −BSP (2). Then, assuming that the first threshold is Pth, it is determined that the detection subject 4 is close and in the detectable area space if PS (1) -BSP (2) = ΔS2> Pth. If ΔS2 ≦ Pth, it is determined that the detection target 4 is not in proximity and is not in the detectable area space.

  When the second ambient light signal detected by the illuminance sensor exceeds the second threshold, a signal Sk of a predetermined intensity is added to ΔPS (2) to generate a second fluctuation component ΔPS (2) + Sk, and BS (BS (2) A noise superimposed reference signal BSP (2) + Sk in which ΔPS (2) + Sk is superimposed on 1) is generated, and a difference ΔS3 between PS (1) and BSP (2) + Sk is obtained. Therefore, the difference ΔS3 = PS (1) − (BSP (2) + Sk). Then, assuming that the first threshold is Pth, it is determined that the detection object 4 is close and in the detectable area space if PS (1)-(BSP (2) + Sk) = ΔS3> Pth. If ΔS3 ≦ Pth, it is determined that the detection target 4 is not in proximity and is not in the detectable area space.

  In the case of the LCD shown in FIG. 6, the detectable area space corresponds to the space from the outer surface of the transparent member 21 to a position approximately 10 cm away in the direction perpendicular thereto. Therefore, the first threshold Pth corresponds to the signal level when light of illuminance of about 20 lx (lux) is received, and in the case of the LCD shown in FIG. 6, from the outer surface of the transparent member 21 to the direction perpendicular thereto. The detection signal level in the case where the detection object 4 such as a human hand is present at a position approximately 10 cm away from the

  Further, as shown in FIG. 6A, when there are two light detection units, as shown in FIG. 2, when one light detection unit is in the first detection state, the other light detection unit is the second one. It is preferable to control to be in the detection state. In this case, the light emitted from the light emitting element 2a (2b) of one light detection unit is not easily received by the light receiving element 3b (3a) of the other light detection unit, and the detection accuracy of each light detection unit is high Can be maintained.

  In the proximity sensor device of the present invention, when the ambient light 7 includes an infrared ray, the light emitting element 2 preferably emits an infrared ray, and the light receiving element 3 preferably detects an infrared ray. In this case, the influence of environmental light 7 such as sunlight including infrared rays can be eliminated to prevent erroneous detection of the detection subject 4. That is, the proximity sensor device can detect human hands and the like that are good reflectors of infrared rays, and eliminate the influence of ambient light 7 such as sunlight and illumination light which causes the largest ambient light signal. it can. In addition, as infrared rays, near infrared rays having a wavelength of about 750 nm to about 1,400 nm are preferable because they are easily reflected by human hands or the like.

  The proximity sensor device of the present invention is applicable to a display device, and as shown in FIG. 6, the display device comprises the proximity sensor device of the present invention, and a plurality of light detection units 1 are mutually connected around the display surface. It is the structure provided with a space | interval. According to this configuration, it is possible to prevent erroneous detection of the detection subject 4 and to improve detection sensitivity of the detection subject 4 and to specify the position of the detection subject 4 with high accuracy. For example, it is preferable that the light detection units 1 be located around the display surface of a display device such as an LCD and at both left and right ends thereof, and that they be at symmetrical positions with respect to the longitudinal center line of the display surface. In this case, it is advantageous to specify the lateral position of the display surface of the detection subject 4. In addition, it is preferable that the light detection unit 1 be provided around the display surface and at both left and right ends thereof and further at at least one of the upper and lower ends. In this case, it is advantageous to specify the position in the plane of the display surface of the detection subject 4.

  In addition, since the display device includes the proximity sensor device of the present invention, the screen display is activated when a finger or the like of a person approaches the display surface. Display operation can be performed such as displaying a hidden operation unit, switching still image display to moving image display, or setting screen display to a plurality of screen displays. Furthermore, by using a hologram or the like, an operation unit such as an icon or a touch button can be displayed in the space in front of the display surface.

  One example of the display device is the LCD shown in FIG. 6, and the LCD has the following configuration. In the LCD, an array side substrate made of a glass substrate or the like on which a large number of pixel portions including TFTs are formed and a color filter side substrate made of a glass substrate or the like on which a color filter and a black matrix are formed face each other. The substrates are laminated at predetermined intervals, and liquid crystal is filled and sealed between the substrates to produce the liquid crystal. Also, in general, the color filter side substrate is a liquid crystal between the pixel electrode and the entire surface on the side opposite to the pixel portion consisting of the pixel electrode consisting of a transparent electrode such as TFT and ITO, that is, the liquid crystal side. A common electrode is formed to form a vertical electric field applied to the In the case of an IPS (In-Plane Switching) LCD, this common electrode is formed in the same plane as the pixel electrode in the pixel portion of the array side substrate to generate a horizontal electric field (horizontal electric field). Further, in the case of an FFS (Fringe Field Switching) LCD, the common electrode is formed on the pixel portion of the array side substrate with an insulating layer interposed above or below the pixel electrode to generate an edge electric field (fringe electric field). It will In addition, red (R), green (G), and blue (B) color filters corresponding to each pixel portion are formed on the liquid crystal side surface of the color filter side substrate, and light passing through each pixel portion is formed. A black matrix is formed to surround the outer periphery of the color filter to prevent the two from interfering with each other. An overcoat layer is formed to cover the color filter, and a common electrode is formed on the overcoat layer. Further, the entire periphery of the edge of the surface on the liquid crystal side of the array side substrate and the entire periphery of the edge of the surface on the liquid crystal side of the color filter side substrate are bonded by a sealing member made of silicone resin, epoxy resin, synthetic rubber , Is sealed. Further, in a portion of the surface on the liquid crystal side of the array side substrate that protrudes outside from the sealing member, a gate signal line drive circuit element composed of IC, LSI, etc., and a semiconductor element as an image signal line drive circuit element A flexible printed circuit (FPC), which is mounted by a mounting method such as a chip on glass method, and further inputs and outputs a drive signal and a control signal to the semiconductor element from the outside, is disposed at an end of the projecting portion. . In addition, a transparent protective substrate called a cover glass is provided on the display-side surface of the color filter side substrate via an OCA or the like.

  The display device is not limited to the LCD, and an organic EL (Electro Luminescence) device, an inorganic EL device, a plasma display, an FED (Field Emitting Display), an SED (Surface-conduction Electron-emitter Display), a GLV (Grading Light Valve) These include a PDP (Plasma Display) device, an electronic paper display, a DMD (Digital micro Mirror Device), a piezoelectric ceramic display, an LED display, and the like. Furthermore, electronic devices having these display devices include car route guidance systems (car navigation systems), ship route guidance systems, aircraft route guidance systems, smart phone terminals, mobile phones, tablet terminals, personal digital assistants (PDAs), videos Camera, digital still camera, electronic notebook, electronic book, electronic dictionary, computer, personal computer, copier, terminal device of game machine, television, commodity display tag, price display tag, industrial programmable display, car audio, Digital audio player, fax machine, printer, automated teller machine (ATM), vending machine, head-up display device, projector device, digital display watch, smart watch, head-mounted image Display device (Head Mounted Display device: HMD), and the like.

  The proximity sensor device of the present invention is not limited to the above embodiment, but may include appropriate design changes and improvements.

DESCRIPTION OF SYMBOLS 1 light detection unit 2 light emitting element 3 light receiving element 4 to-be-detected body 5 detection signal processing part 6 detection control part 7 ambient light 8 illuminance sensor 11 detection signal 12 reference signal 11a, 13a 1st fluctuation based on a 1st environmental light signal Component 11 b Signal 12 a of predetermined intensity Reference signal on which the second fluctuation component based on the third ambient light signal is superimposed

Claims (5)

A light detection unit having a light emitting element and a light receiving element, a detection signal processing unit for detecting the proximity of an object to be detected based on a detection signal of the light receiving element, the light emitting element is in a light emitting state, and the light receiving element is in a light receiving state Control for alternately repeating a first detection state which is the second light detection state in which the light emitting element is in the non-light emission state and the light receiving element is in the light reception state to detect the ambient light Unit and an illuminance sensor, wherein the detection signal processing unit is configured to calculate a first difference between a difference between the detection signal and a reference signal formed by delaying the detection signal for a predetermined time in the first detection state. When the proximity or non-proximity of the object to be detected is detected by comparison with a threshold, and the ambient light is detected by the light receiving element and the illuminance sensor in the second detection state A proximity sensor device for acquiring a first ambient light signal detected by a child and a second ambient light signal detected by the illuminance sensor, wherein the detection signal processing unit further comprises: When it is not more than the threshold of 2, the first fluctuation component of the first ambient light signal is superimposed on the reference signal in the first detection state, and the difference with the detection signal is obtained, and the difference and the second The proximity or non-proximity of the detection target is detected by comparing the threshold with one, and when the second ambient light signal exceeds the second threshold, a signal of a predetermined intensity in the first ambient light signal. To generate a third ambient light signal, superimposing a second fluctuation component of the third ambient light signal on the reference signal in the first detection state, and calculating a difference from the detection signal. Comparing the difference with the first threshold Proximity sensor device for detecting the proximity or non-proximity of the object to be detected by the.
  The proximity sensor device according to claim 1, wherein the signal of the predetermined intensity is 5% to 100% of the intensity of the second ambient light signal.   The proximity sensor device according to claim 1, wherein the reference signal is a delay signal obtained by delaying the detection signal by 100 msec to 500 msec.   The first variation component is a first difference signal between the first ambient light signal and the non-detection signal obtained when the ambient light is not detected by the light receiving element in the second detection state. The proximity sensor device according to any one of claims 1 to 3, wherein the second fluctuation component is a second difference signal between the third ambient light signal and the non-detection signal.   The proximity sensor device according to any one of claims 1 to 4, wherein when the ambient light includes infrared light, the light emitting element emits infrared light and the light receiving element detects infrared light.