JP2010199706A - Proximity sensor with illuminance detection function and electronic device - Google Patents

Abstract

Provided is a proximity sensor with an illuminance detection function capable of reducing power consumption without impairing the accuracy of detecting the proximity state of an object to be detected.
An illuminance determination circuit 23 determines whether or not the illuminance detected by the illuminance sensor 13 exceeds a first illuminance threshold. When the illuminance determination circuit 23 determines that the illuminance exceeds the first illuminance threshold, the control circuit 21 controls the light emitting element 11 so that the light emitting element 11 stops emitting light.
[Selection] Figure 2

Description

  The present invention relates to a proximity sensor with an illuminance detection function and an electronic device.

  In general, the optical proximity sensor has a hygienic merit as a non-contact switch, and thus has been used for switches of sanitary equipment such as automatic water washing. Recently, in order to reduce power consumption of mobile phones, optical proximity sensors have been mounted on mobile phones. In other words, when the incoming call is received, it is detected that the speakerphone of the mobile phone is brought close to the ear, and the liquid crystal backlight is turned off to reduce wasteful power consumption.

  Conventionally, as an optical proximity sensor, for example, as shown in Japanese Patent Laid-Open Nos. 11-354832, 2002-84177, and 2007-52928, a light emitting element that emits light and a light receiving device. The light emitting element and the light receiving element are each molded with a primary molding resin. In addition, in order to prevent light emitted from the light emitting element from being directly received by the light receiving element, the light emitting element and the light receiving element are optically separated by a secondary mold resin having a light shielding property.

  Here, when the detected object is in the proximity state, the light emitted from the light emitting element is reflected by the detected object, and the reflected light is received by the light receiving element. When the object to be detected is not in the proximity state, the light emitted from the light emitting element diffuses and is not received by the light receiving element. Thus, the proximity state of the detection object can be detected by measuring the amount of light received by the light receiving element.

Japanese Patent Laid-Open No. 11-354832 JP 2002-84177 A JP 2007-52928 A

  However, in the conventional optical proximity sensor described above, in order to detect the proximity state of the object to be detected, the light is always emitted from the light emitting element, and thus the power of the optical proximity sensor itself is wasted. was there.

  Accordingly, an object of the present invention is to provide a proximity sensor with an illuminance detection function that can reduce power consumption without impairing the accuracy of detecting the proximity state of an object to be detected.

In order to solve the above problems, the proximity sensor with illuminance detection function of the present invention is
A light emitting element that emits light;
A light receiving element that receives reflected light from an object to be detected of light emitted by the light emitting element;
A received light amount determination circuit that determines whether the amount of reflected light received by the light receiving element exceeds a determination threshold;
An illuminance sensor that detects the illuminance around the
An illuminance determination circuit that determines whether the illuminance detected by the illuminance sensor exceeds a first illuminance threshold;
The light emitting element stops emitting light when receiving the outputs of the received light amount determination circuit and the illuminance determination circuit and when the illuminance determination circuit determines that the illuminance exceeds a first illuminance threshold. And a control circuit for controlling the light emitting element.

  According to the proximity sensor with illuminance detection function of the present invention, the received light amount determination circuit determines whether or not the amount of reflected light received by the light receiving element exceeds a determination threshold, and the amount of reflected light is determined by the determination threshold. Is exceeded, it is determined that the detected object is in proximity to the proximity sensor.

  The illuminance determination circuit determines whether or not the illuminance detected by the illuminance sensor exceeds the first illuminance threshold, and when the illuminance exceeds the first illuminance threshold, Judge that it is bright. That is, when the surroundings are sufficiently bright and the object to be detected is not in the proximity state, it is detected by the illumination determination circuit that the ambient illumination is bright. When it is detected that the illuminance determination circuit is sufficiently bright, it is possible to detect that the detected object is not in proximity without emitting light from the light emitting element.

  The control circuit receives the outputs of the received light amount determination circuit and the illuminance determination circuit, and when the illuminance determination circuit determines that the illuminance exceeds the first illuminance threshold, the light emitting element stops emitting light. Thus, since the light emitting element is controlled, when the surroundings are sufficiently bright, the object to be detected is not in the proximity state, and it is not necessary to radiate light from the light emitting element, and the power consumption of the proximity sensor can be reduced.

In the proximity sensor with an illuminance detection function of one embodiment,
The control circuit is
While controlling the light emitting element so that the light emitting element emits pulses at a constant period,
The illuminance sensor so that the illuminance sensor detects illuminance when the illuminance sensor stops emitting light while the illuminance sensor emits light, while the illuminance sensor detects illuminance when the light emitting element does not emit light. To control.

  According to the proximity sensor with an illuminance detection function of this embodiment, since the control circuit causes the light emitting element to emit light in a constant cycle, the pulse light emission period of the light emitting element is sufficiently short relative to the moving speed of the detected object. In this case, the power consumption of the proximity sensor can be reduced without impairing the accuracy of detecting the proximity state of the detected object, compared to when the light emitting element continuously emits light.

  In addition, the control circuit stops the detection of the illuminance when the light emitting element is emitting light, while the illuminance sensor detects the illuminance when the light emitting element is not emitting light. Since the illuminance sensor is controlled, the illuminance sensor stops detecting the illuminance while the light emitting element emits light, so that the reflected light from the detected object is received by the illuminance sensor and the ambient illuminance is detected. And the power consumption of the illuminance sensor can be reduced.

In the proximity sensor with an illuminance detection function of one embodiment,
When the illuminance determination circuit determines that the illuminance detected by the illuminance sensor is equal to or less than a second illuminance threshold smaller than the first illuminance threshold,
The control circuit controls the light emitting element so as to lower the emission intensity of light emitted from the light emitting element, and controls the received light amount determination circuit so as to lower the determination threshold.

  According to the proximity sensor with an illuminance detection function of this embodiment, when the illuminance determination circuit determines that the illuminance is equal to or less than the second illuminance threshold, the proximity sensor is determined to be dark. In other words, if the surroundings are sufficiently dark, or the surroundings are bright and the object to be detected is in close proximity and the ambient light is in a position that prevents it from being received by the illuminance sensor, the illuminance determination circuit Is detected to be dark.

  When the surroundings are dark, the amount of reflected light from the object to be detected is relatively large relative to the amount of ambient light, so the control circuit lowers the emission intensity of light emitted from the light emitting element and lowers the determination threshold. Thus, the power consumption of the proximity sensor can be reduced without impairing the accuracy of detecting the proximity state of the detected object.

In the proximity sensor with an illuminance detection function of one embodiment,
The illuminance determination circuit determines that the illuminance detected by the illuminance sensor is equal to or less than a second illuminance threshold smaller than the first illuminance threshold, and the received light amount determination circuit receives the light receiving element. When it is determined that the amount of reflected light exceeds the determination threshold,
The control circuit controls the light emitting element so as to shorten a light emission period of pulse light emission of the light emitting element.

  According to the proximity sensor with an illuminance detection function of this embodiment, when the illuminance determination circuit determines that the illuminance is equal to or less than the second illuminance threshold, the proximity sensor is determined to be dark. When the received light amount determination circuit determines that the amount of reflected light exceeds the determination threshold, it determines that the detected object is in proximity to the proximity sensor.

  When the surroundings are dark and the object to be detected is in the proximity state, the control circuit can reduce power consumption by controlling the light emitting element so as to shorten the light emission period of the pulse light emission of the light emitting element. it can. At this time, since the ambient illuminance is dark, the SN is maintained even if the light emission period of the pulse light emission is shortened. Therefore, the power consumption of the proximity sensor can be reduced without impairing the accuracy of detecting the proximity state of the detected object.

In the proximity sensor with an illuminance detection function of one embodiment,
When the illuminance determination circuit determines that the illuminance detected by the illuminance sensor does not change within a certain time,
The control circuit controls the light emitting element such that the light emitting element stops emitting light.

  According to the proximity sensor with an illuminance detection function of this embodiment, when the illuminance determination circuit determines that the illuminance detected by the illuminance sensor does not change within a certain period of time, the detected object is in the proximity or separation state. Is determined to be held.

  Then, at this time, the control circuit controls the light emitting element so that the light emitting element stops emitting light, so that the accuracy of detecting the proximity state of the detected object is not impaired, and the proximity sensor consumption is reduced. Electric power can be reduced.

  On the other hand, when the illuminance determination circuit determines that the illuminance detected by the illuminance sensor has changed within a certain period of time, it is determined that the detected object has moved to either a proximity state or a separation state. At this time, the control circuit emits light from the light emitting element by controlling the light emitting element so that the light emitting element starts emitting light.

In the proximity sensor with an illuminance detection function of one embodiment,
When the illuminance determination circuit determines that the illuminance detected by the illuminance sensor does not change within a certain time,
The control circuit controls the light emitting element so as to lower the emission intensity of light emitted from the light emitting element, and controls the received light amount determination circuit so as to lower the determination threshold.

  According to the proximity sensor with an illuminance detection function of this embodiment, when the illuminance determination circuit determines that the illuminance detected by the illuminance sensor does not change within a certain period of time, the detected object is in the proximity or separation state. Is determined to be held.

  At this time, the control circuit controls the light emitting element so as to reduce the emission intensity of the light emitted from the light emitting element, and reduces the determination threshold value so as to reduce the determination threshold value. By controlling, power consumption of the proximity sensor can be reduced without impairing the accuracy of detecting the proximity state of the detected object.

  On the other hand, when the illuminance determination circuit determines that the illuminance detected by the illuminance sensor has changed within a certain period of time, it is determined that the detected object has moved to either a proximity state or a separation state. At this time, the control circuit controls the light emitting element so as to restore (increase) the radiation intensity of light emitted by the light emitting element, and restores (increases) the determination threshold value. Controls the received light amount determination circuit.

In the proximity sensor with an illuminance detection function of one embodiment,
The illuminance determination circuit determines that the illuminance detected by the illuminance sensor does not change within a certain time, and the received light amount determination circuit determines that the amount of reflected light received by the light receiving element exceeds the determination threshold. When it is determined that
The control circuit controls the light emitting element so as to shorten a light emission period of pulse light emission of the light emitting element.

  According to the proximity sensor with an illuminance detection function of this embodiment, when the illuminance determination circuit determines that the illuminance detected by the illuminance sensor does not change within a certain period of time, the detected object is in the proximity or separation state. Is determined to be held. When the received light amount determination circuit determines that the amount of reflected light exceeds the determination threshold, it determines that the detected object is in proximity to the proximity sensor.

  When the object to be detected is in the proximity state, the control circuit can reduce power consumption by controlling the light emitting element so as to shorten the light emission period of the pulse light emission of the light emitting element. . At this time, since the ambient illuminance is dark, the SN is maintained even if the light emission period of the pulse light emission is shortened. Therefore, the power consumption of the proximity sensor can be reduced without impairing the accuracy of detecting the proximity state of the detected object.

  Moreover, in the proximity sensor with an illuminance detection function according to one embodiment, the light emitted from the light emitting element is infrared light.

  According to the proximity sensor with an illuminance detection function of this embodiment, since the light emitted from the light emitting element is infrared light, the wavelength region of the light received by the illuminance sensor is changed to visible light from the light emitting element. It is possible to prevent the emitted light from being received by the illuminance sensor and erroneously detecting the ambient illuminance.

  Furthermore, in an environment where the amount of infrared light is relatively small compared to the amount of visible light, such as under a fluorescent lamp, the influence of disturbance light on the proximity sensor can be reduced. Further, when the proximity sensor is operated, it can be made inconspicuous in appearance.

  An electronic apparatus according to the present invention includes the proximity sensor with an illuminance detection function.

  According to the electronic device of the present invention, since the proximity sensor with the illuminance detection function is provided, the power consumption of the electronic device can be reduced by using the proximity sensor with low power consumption.

  In the electronic apparatus according to an embodiment, the illuminance information obtained from the illuminance sensor is obtained when the received light amount determination circuit determines that the amount of reflected light received by the light receiving element exceeds the determination threshold. ignore.

  According to the electronic apparatus of this embodiment, when the received light amount determination circuit determines that the amount of reflected light exceeds the determination threshold, it determines that the detected object is in the proximity state of the electronic apparatus.

  For example, when this electronic device is a device that reduces power consumption by adjusting the luminance of the backlight of the liquid crystal monitor according to the ambient illuminance detected by the illuminance sensor, the detected object is in the proximity state When the ambient light is in a positional relationship that prevents the ambient light from being received by the illuminance sensor, it is possible to prevent erroneous detection that the ambient illuminance is dark by ignoring the illuminance information obtained from the illuminance sensor.

  That is, even when the illuminance determination circuit detects that the ambient illuminance is dark, if the detected object is in the proximity state, the luminance of the backlight is not increased unnecessarily, and the power consumption of the electronic device increases. Can be prevented.

  In the electronic device according to an embodiment, when the illuminance determination circuit determines that the illuminance detected by the illuminance sensor exceeds a first illuminance threshold, information on reflected light obtained from the light receiving element is obtained. ignore.

  According to the electronic device of this embodiment, when the illuminance determination circuit determines that the illuminance detected by the illuminance sensor exceeds the first illuminance threshold, the surroundings of the electronic device are determined to be bright.

  When the object to be detected is not in the proximity state, even if the ambient illuminance is sufficiently bright and ambient light is received by the light receiving element, the illuminance determination circuit detects that the ambient illuminance is sufficiently bright and By ignoring the information of the obtained reflected light, it is possible to prevent erroneous detection of the proximity state of the detected object.

  According to the proximity sensor with an illuminance detection function of the present invention, the control circuit receives the outputs of the received light amount determination circuit and the illuminance determination circuit, and the illuminance determination circuit determines that the illuminance exceeds the first illuminance threshold value. In some cases, since the light emitting element is controlled so that the light emitting element stops emitting light, the power consumption of the proximity sensor can be reduced without impairing the accuracy of detecting the proximity state of the detected object.

  According to the electronic device of the present invention, since the proximity sensor with the illuminance detection function is provided, the power consumption of the electronic device can be reduced.

It is a simplified lineblock diagram showing a 1st embodiment of a proximity sensor with an illuminance detection function of the present invention. The block diagram of a proximity sensor with an illuminance detection function is shown. It is a graph which shows 2nd Embodiment of the proximity sensor with an illumination intensity detection function of this invention, and shows the operation timing of a proximity sensor. It is a graph which shows 3rd Embodiment of the proximity sensor with an illumination intensity detection function of this invention, and shows the operation timing of a proximity sensor. It is a graph which shows 4th Embodiment of the proximity sensor with an illumination intensity detection function of this invention, and shows the operation timing of a proximity sensor. It is a graph which shows 5th Embodiment of the proximity sensor with an illumination intensity detection function of this invention, and shows the operation timing of a proximity sensor. It is a graph which shows the operation timing of a proximity sensor while showing 6th Embodiment of the proximity sensor with an illumination intensity detection function of this invention. It is a graph which shows the operation timing of a proximity sensor while showing 7th Embodiment of the proximity sensor with an illumination intensity detection function of this invention. It is a perspective view which shows the mobile telephone as an electronic device of this invention. It is a front view which shows the digital camera as an electronic device of this invention. It is a perspective view which shows the other mobile telephone as an electronic device of this invention. It is explanatory drawing explaining an effect | action of the electronic device of this invention. It is a flowchart which shows operation | movement of the proximity sensor with another illumination intensity detection function of this invention. It is a flowchart which shows operation | movement of the proximity sensor with another illumination intensity detection function of this invention. It is a flowchart which shows operation | movement of the proximity sensor with another illumination intensity detection function of this invention. It is a flowchart which shows operation | movement of the proximity sensor with another illumination intensity detection function of this invention.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

(First embodiment)
FIG. 1 shows a simplified configuration diagram as an embodiment of a proximity sensor with an illuminance detection function of the present invention. As shown in FIG. 1, the proximity sensor 10 includes a light emitting element 11 that emits light, a light receiving element 12 that receives light, and an illuminance sensor 13 that detects ambient illuminance.

  The light emitting element 11, the light receiving element 12, and the illuminance sensor 13 are attached to the same surface of the substrate 14 at intervals. The light emitting element 11, the light receiving element 12, and the illuminance sensor 13 are oriented in the same direction.

  The light emitting element 11, the light receiving element 12, and the illuminance sensor 13 are each molded with a primary mold resin 15.

  Between the light emitting element 11, the light receiving element 12, and the illuminance sensor 13, a secondary mold resin 16 having a light shielding property is provided. The secondary mold resin 16 optically separates the light emitting element 11, the light receiving element 12, and the illuminance sensor 13, and the light emitted from the light emitting element 11 is directly received by the light receiving element 12 and the illuminance sensor 13. prevent.

  In order to reduce the influence of the light receiving element 12 receiving ambient light, the wavelength region of the light received by the light receiving element 12 is matched with the wavelength region of the light emitted from the light emitting element 11 in the primary mold resin. It is desirable to mix a dye or the like that absorbs light outside the specific wavelength region into a portion of the light receiving element 12 that is molded, or to introduce a band-pass filter into the receiving circuit.

  The wavelength region of the light received by the illuminance sensor 13 is a visible light region, and the illuminance sensor 13 of the primary mold resin 15 is used in order to reduce the influence caused by receiving the light emitted from the light emitting element 11. It is desirable to mix a material that absorbs only light in the wavelength region emitted from the light emitting element 11 into the portion where the material is molded.

  As shown in FIG. 2, when the detected object 20 is in proximity to the proximity sensor 10, the emitted light 24 emitted by the light emitting element 11 is reflected by the detected object 20 and reflected light 25 from the detected object 20. Is received by the light receiving element 12.

  The light receiving element 12 generates a current S 1 corresponding to the amount of reflected light 25 and inputs the current S 1 to the received light amount determination circuit 22. The received light amount determination circuit 22 determines whether or not the light amount of the reflected light 25 received by the light receiving element 12 exceeds a determination threshold value.

  That is, the received light amount determination circuit 22 compares a preset determination threshold value with the current value S1, and if the current value S1 exceeds the determination threshold value, the received light amount determination circuit 22 sends the high level signal S2 to the control circuit 21. Enter. The high level signal S2 means that the detected object 20 is in proximity to the proximity sensor 10.

  On the other hand, when the received light amount determination circuit 22 determines that the amount of the reflected light 25 is less than or equal to the determination threshold, the received light amount determination circuit 22 inputs a low level signal to the control circuit 21. The low level signal means that the detected object 20 is not in proximity to the proximity sensor 10.

  Here, when the surroundings are sufficiently bright, the ambient light 26 is blocked by the detected object 20 and is not received by the illuminance sensor 13.

  When the detected object 20 is not in proximity to the proximity sensor 10, the emitted light 24 emitted from the light emitting element 11 is diffused, and the emitted light 24 is not received by the light receiving element 12. However, if the surroundings are sufficiently bright here, the ambient light 26 is received by the light receiving element 12 and the illuminance sensor 13.

  The illuminance sensor 13 generates a current S 3 corresponding to the amount of ambient light 26 and inputs the current S 3 to the illuminance determination circuit 23. The illuminance determination circuit 23 determines whether the illuminance detected by the illuminance sensor 13 exceeds a first illuminance threshold.

  That is, the illuminance determination circuit 23 compares the preset first illuminance threshold value with the current value S3. If the current value S3 exceeds the first illuminance threshold value, the illuminance determination circuit 23 determines that the high level signal S4 is high. Is input to the control circuit 21. The high level signal S4 means that the surroundings are sufficiently bright and the detected object 20 is not in the proximity state.

  On the other hand, when the illuminance determination circuit 23 determines that the illuminance is equal to or less than the first illuminance threshold, the illuminance determination circuit 23 inputs a low level signal to the control circuit 21. A low level signal means that the surrounding is dark.

  The control circuit 21 receives the outputs of the received light amount determination circuit 22 and the illuminance determination circuit 23, and when the illuminance determination circuit 23 determines that the illuminance exceeds the first illuminance threshold, the light emitting element 11 emits light. The light emitting element 11 is controlled so as to stop the emission.

  That is, as long as the illuminance determination circuit 23 inputs the high level signal S4 to the control circuit 21, the control circuit 21 stops emitting light from the light emitting element 11 and reduces the power consumption of the proximity sensor 10. Can do.

  When the ambient light 26 includes a wavelength component close to the wavelength region of the outgoing light 24 emitted from the light emitting element 11, the ambient light 26 is received by the light receiving element 12, so that the received light amount determination circuit 22 is high as described above. The level signal S2 is input to the control circuit 21. In this way, the illuminance determination circuit 23 sends the high level signal S4 to the control circuit 21 in order to prevent erroneous detection that the detected object 20 is in the proximity state even though the detected object 20 is not in the proximity state. If it is input, the control circuit 21 outputs a low level signal S5 to the outside. The low level signal S5 means that the detected object 20 is not in the proximity state. On the other hand, when the detected object 20 is in the proximity state, a high level signal is output from the control circuit 21 to the outside.

  According to the proximity sensor 10 having the above configuration, the received light amount determination circuit 22 determines whether or not the light amount of the reflected light 25 received by the light receiving element 12 exceeds a determination threshold value, and determines the light amount of the reflected light 25. When the threshold value is exceeded, it is determined that the detected object 20 is in proximity to the proximity sensor 10.

  The illuminance determination circuit 23 determines whether or not the illuminance detected by the illuminance sensor 13 exceeds a first illuminance threshold. When the illuminance exceeds the first illuminance threshold, the proximity sensor 10 Judging that the surroundings are bright. That is, when the surroundings are sufficiently bright and the detected object 20 is not in the proximity state, the illuminance determination circuit 23 detects that the ambient illuminance is bright. When the illuminance determination circuit 23 detects that it is sufficiently bright, it can be detected that the detected object 20 is not in proximity without emitting light from the light emitting element 11.

  The control circuit 21 receives the outputs of the received light amount determination circuit 22 and the illuminance determination circuit 23, and when the illuminance determination circuit 23 determines that the illuminance exceeds the first illuminance threshold, the light emitting element 11 Since the light emitting element 11 is controlled so as to stop the emission of light, when the surroundings are sufficiently bright, the detected object 20 is not in the proximity state, and it is not necessary to emit light from the light emitting element 11. Power consumption can be reduced.

(Second Embodiment)
FIG. 3 shows a second embodiment of the proximity sensor with illuminance detection function of the present invention. When the difference from the first embodiment is described, the control method of the control circuit is different in the second embodiment.

  In the second embodiment, referring to FIG. 2, the control circuit 21 controls the light emitting element 11 so that the light emitting element 11 emits pulses at a constant cycle. The control circuit 21 causes the illuminance sensor 13 to detect the illuminance when the light emitting element 11 is emitting light, while the illuminance sensor 13 stops detecting the illuminance when the light emitting element 11 is emitting light. In addition, the illuminance sensor 13 is controlled.

  That is, as shown in FIG. 3, the operation timing of the light emitting element 11 and the light receiving element 12 is indicated by reference numeral 30 in FIG. 3A, and the light receiving intensity of the light receiving element 12 is indicated by the reference numeral in FIG. 31.

  When the detected object 20 is not near the proximity sensor 10, pulsed light is not received by the light receiving element 12, and when the detected object 20 approaches, the light receiving intensity of the light receiving element 12 increases and exceeds the determination threshold 32. And the detected object 20 are detected.

  The operation timing of the illuminance sensor 13 is indicated by reference numeral 33 in FIG. 3C, and the illuminance sensor 13 operates during a period in which light is not emitted in the pulse light emission of the light emitting element 11.

  The received light intensity of the illuminance sensor 13 is indicated by reference numeral 34 in FIG. When the surroundings are sufficiently bright and the detected object 20 is not near the proximity sensor 10, the illuminance sensor 13 receives ambient light. However, when the detected object 20 approaches, the ambient light is blocked, and the received light intensity of the illuminance sensor 13 is increased. Decrease.

  According to the proximity sensor configured as described above, the control circuit 21 causes the light emitting element 11 to emit light in a constant cycle, and therefore the pulse light emission period of the light emitting element 11 is sufficiently short with respect to the moving speed of the detected object 20. Compared to when the light emitting element 11 emits light continuously, the power consumption of the proximity sensor can be reduced without impairing the accuracy of detecting the proximity state of the detected object 20.

  Further, the control circuit 21 is configured such that the illuminance sensor 13 stops detecting the illuminance when the light emitting element 11 emits light, while the illuminance sensor 13 reduces the illuminance when the light emitting element 11 is not emitting light. Since the illuminance sensor 13 is controlled so as to detect, the illuminance sensor 13 stops detecting the illuminance while the light emitting element 11 emits light, so that the reflected light from the detected object 20 is illuminance. The light received by the sensor 13 does not affect the detection of ambient illuminance, and the power consumption of the illuminance sensor 13 can be reduced.

(Third embodiment)
FIG. 4 shows a third embodiment of the proximity sensor with illuminance detection function of the present invention. The difference from the first embodiment will be described. In the third embodiment, the control method of the control circuit is different.

  In the third embodiment, referring to FIG. 2, when the illuminance determination circuit 23 determines that the illuminance detected by the illuminance sensor 13 is equal to or smaller than the second illuminance threshold smaller than the first illuminance threshold. The control circuit 21 controls the light emitting element 11 so as to reduce the radiation intensity of the light emitted from the light emitting element 11, and controls the received light amount determination circuit 22 so as to lower the determination threshold value.

  That is, as shown in FIG. 4, the light receiving intensity of the illuminance sensor 13 is indicated by reference numeral 40 in FIG. 4A, and the radiation intensity of the light emitting element 11 is indicated by reference numeral 42 in FIG. 4B. The received light intensity of the light receiving element 12 is shown in FIG. When the light intensity 40 of the illuminance sensor 13 is equal to or less than the second illuminance threshold value 41, the radiation intensity 42 of the light emitted from the light emitting element 11 is lowered and the determination threshold value 43 is lowered.

  According to the proximity sensor having the above configuration, when the illuminance determination circuit 23 determines that the illuminance is equal to or less than the second illuminance threshold, it determines that the vicinity of the proximity sensor is dark. In other words, if the surroundings are sufficiently dark or the detected object 20 is in the proximity state even if the surroundings are bright and the ambient light is prevented from being received by the illumination sensor 13, the illumination determination circuit 23 It is detected that the ambient illuminance is dark.

  When the surroundings are dark, the amount of light reflected from the detected object 20 with respect to the amount of ambient light is relatively large. Therefore, the control circuit 21 reduces the radiation intensity of the light emitted from the light emitting element 11 and sets the determination threshold value. By making it low, the power consumption of the proximity sensor can be reduced without impairing the accuracy of detecting the proximity state of the detected object 20.

(Fourth embodiment)
FIG. 5 shows a fourth embodiment of the proximity sensor with illuminance detection function of the present invention. The difference from the first embodiment will be described. In the fourth embodiment, the control method of the control circuit is different.

  In the fourth embodiment, referring to FIG. 2, the illuminance determination circuit 23 determines that the illuminance detected by the illuminance sensor 13 is equal to or smaller than a second illuminance threshold smaller than the first illuminance threshold, and When the received light amount determination circuit 22 determines that the amount of reflected light received by the light receiving element 12 exceeds the determination threshold, the control circuit 21 shortens the light emission period of the pulse light emission of the light emitting element 11. The light emitting element 11 is controlled.

  That is, as shown in FIG. 5, the light reception intensity of the illuminance sensor 13 is indicated by reference numeral 50 in FIG. 5A, and the light reception intensity of the light receiving element 12 is indicated by reference numeral 52 in FIG. 5B. The radiant intensity of the light emitting element 11 is indicated by reference numeral 54 in FIG. Then, when it is detected that the light reception intensity 50 of the illuminance sensor 13 is equal to or less than the second illuminance threshold value 51 and when it is detected that the light reception intensity 52 of the light reception element 12 exceeds the determination threshold value 53, As indicated by the radiation intensity 54, the light emission period is shortened in the pulse light emission of the light emitting element 11.

  According to the proximity sensor having the above configuration, when the illuminance determination circuit 23 determines that the illuminance is equal to or less than the second illuminance threshold, it determines that the vicinity of the proximity sensor is dark. When the received light amount determination circuit 22 determines that the amount of reflected light exceeds the determination threshold, it determines that the detected object 20 is in proximity to the proximity sensor.

  When the surroundings are dark and the detected object 20 is in the proximity state, the control circuit 21 controls the light emitting element 11 so as to shorten the light emission period of the pulse light emission of the light emitting element 11, thereby reducing the power consumption. Can be reduced. At this time, since the ambient illuminance is dark, the SN is maintained even if the light emission period of the pulse light emission is shortened. Therefore, the power consumption of the proximity sensor can be reduced without impairing the accuracy of detecting the proximity state of the detected object 20.

(Fifth embodiment)
FIG. 6 shows a fifth embodiment of the proximity sensor with illuminance detection function of the present invention. The difference from the first embodiment will be described. In the fifth embodiment, the control method of the control circuit is different.

  In the fifth embodiment, referring to FIG. 2, when the illuminance determination circuit 23 determines that the illuminance detected by the illuminance sensor 13 does not change within a certain time, the control circuit 21 causes the light emitting element 11 to The light emitting element 11 is controlled so as to stop the emission of light.

  That is, as shown in FIG. 6, the received light intensity of the illuminance sensor 13 is indicated by reference numeral 60 in FIG. 6A, and the radiant intensity of the light emitting element 11 is indicated by reference numeral 61 in FIG. 6B. The received light intensity of the light receiving element 12 is indicated by reference numeral 62 in FIG. When it is detected that the light receiving intensity 60 of the illuminance sensor 13 does not change within a certain time, the light emission from the light emitting element 11 is stopped, and when the light receiving intensity 60 changes within a certain time, the light emitting element 11 Emits light.

  It is the illuminance determination circuit 23 that determines whether or not the received light intensity 60 has changed within a certain period of time. The illuminance determination circuit 23 receives at least two periods of output signals from the illuminance sensor 13 that operates during a period in which light is not emitted in the pulse light emission of the light emitting element 11, compares the signal levels for two periods, Detect change.

  The illuminance determination circuit 23 stores a certain reference amount 64 with respect to the change in illuminance, and determines that the received light intensity has changed when the change amount exceeds the reference amount.

  Information on whether or not the light receiving intensity 62 of the light receiving element 12 has exceeded the determination threshold 63 is maintained until the next change in illuminance occurs, light is emitted from the light emitting element 11 and received by the light receiving element 12, and the light receiving intensity is determined. .

  According to the proximity sensor having the above-described configuration, when the illuminance determination circuit 23 determines that the illuminance detected by the illuminance sensor 13 does not change within a certain time, the detected object 20 maintains either the proximity state or the separation state. It is judged that

  At this time, the control circuit 21 controls the light emitting element 11 so that the light emitting element 11 stops the emission of light without impairing the accuracy of detecting the proximity state of the detected object 20. The power consumption of the proximity sensor can be reduced.

  On the other hand, when the illuminance determination circuit 23 determines that the illuminance detected by the illuminance sensor 13 has changed within a certain period of time, it is determined that the detected object 20 has moved to either the proximity or separation state. . At this time, the control circuit 21 emits light from the light emitting element 11 by controlling the light emitting element 11 so that the light emitting element 11 starts emitting light.

(Sixth embodiment)
FIG. 7 shows a sixth embodiment of the proximity sensor with illuminance detection function of the present invention. The difference from the first embodiment will be described. In the sixth embodiment, the control method of the control circuit is different.

  In the sixth embodiment, referring to FIG. 2, when the illuminance determination circuit 23 determines that the illuminance detected by the illuminance sensor 13 does not change within a certain time, the control circuit 21 causes the light emitting element 11 to The light emitting element 11 is controlled so as to lower the radiation intensity of the emitted light, and the received light amount judgment circuit 22 is controlled so as to lower the judgment threshold.

  That is, as shown in FIG. 7, the received light intensity of the illuminance sensor 13 is indicated by reference numeral 70 in FIG. 7A, and the radiant intensity of the light emitting element 11 is indicated by reference numeral 71 in FIG. 7B. The received light intensity of the light receiving element 12 is shown in FIG. When it is detected that the received light intensity 70 of the illuminance sensor 13 does not change within a certain time, the emission intensity 71 of the light emitted from the light emitting element 11 is lowered and the determination threshold 72 is lowered.

  It is the illuminance determination circuit 23 that determines whether or not the received light intensity 70 has changed within a certain period of time. The illuminance determination circuit 23 receives at least two periods of output signals from the illuminance sensor 13 that operates during a period in which light is not emitted in the pulse light emission of the light emitting element 11, compares the signal levels for two periods, Detect change.

  The illuminance determination circuit 23 stores a certain reference amount 73 with respect to the change in illuminance. When the change amount exceeds the reference amount, it determines that the received light intensity has changed.

  According to the proximity sensor having the above-described configuration, when the illuminance determination circuit 23 determines that the illuminance detected by the illuminance sensor 13 does not change within a certain time, the detected object 20 maintains either the proximity state or the separation state. It is judged that

  At this time, the control circuit 21 controls the light emitting element 11 so as to reduce the radiation intensity of the light emitted from the light emitting element 11, and the light receiving element so as to lower the determination threshold value. By controlling the quantity determination circuit 22, the power consumption of the proximity sensor can be reduced without impairing the accuracy of detecting the proximity state of the detected object 20.

  On the other hand, when the illuminance determination circuit 23 determines that the illuminance detected by the illuminance sensor 13 has changed within a certain period of time, it is determined that the detected object 20 has moved to either the proximity or separation state. . At this time, the control circuit 21 controls the light emitting element 11 so as to restore (increase) the radiation intensity of the light emitted from the light emitting element 11 and restore (increase) the determination threshold. Thus, the received light amount determination circuit 22 is controlled.

(Seventh embodiment)
FIG. 8 shows a seventh embodiment of the proximity sensor with illuminance detection function of the present invention. The difference from the first embodiment will be described. In the seventh embodiment, the control method of the control circuit is different.

  In the seventh embodiment, referring to FIG. 2, the illuminance determination circuit 23 determines that the illuminance detected by the illuminance sensor 13 does not change within a certain time, and the received light amount determination circuit 22 receives the light receiving element. When the control circuit 21 determines that the amount of reflected light received by the light source 12 exceeds the determination threshold, the control circuit 21 controls the light emitting element 11 so as to shorten the light emission period of the pulse light emission of the light emitting element 11.

  That is, as shown in FIG. 8, the received light intensity of the illuminance sensor 13 is indicated by reference numeral 80 in FIG. 8A, and the received light intensity of the light receiving element 12 is indicated by reference numeral 81 in FIG. 8B. The radiant intensity of the light emitting element 11 is indicated by reference numeral 83 in FIG. Then, it is detected that the received light intensity 80 of the illuminance sensor 13 does not change within a certain time, and the received light intensity 81 of the light receiving element 12 exceeds the determination threshold value 82 and it is detected that the detected object 20 is in the proximity state. Sometimes, the light emission period is shortened in the pulsed light emission of the light emitting element 11 as indicated by the radiation intensity 83 of the light emitting element 11.

  It is the illuminance determination circuit 23 that determines whether or not the received light intensity 80 has changed within a certain period of time. The illuminance determination circuit 23 receives at least two periods of output signals from the illuminance sensor 13 that operates during a period in which light is not emitted in the pulse light emission of the light emitting element 11, compares the signal levels for two periods, Detect change.

  The illuminance determination circuit 23 stores a certain reference amount 84 with respect to the illuminance change, and determines that the received light intensity has changed when the change amount exceeds the reference amount.

  According to the proximity sensor having the above-described configuration, when the illuminance determination circuit 23 determines that the illuminance detected by the illuminance sensor 13 does not change within a certain time, the detected object 20 maintains either the proximity state or the separation state. It is judged that When the received light amount determination circuit 22 determines that the amount of reflected light exceeds the determination threshold, it determines that the detected object 20 is in proximity to the proximity sensor.

  When the detected object 20 is in the proximity state, the control circuit 21 controls the light emitting element 11 so as to shorten the light emission period of the pulse light emission of the light emitting element 11, thereby reducing power consumption. can do. At this time, since the ambient illuminance is dark, the SN is maintained even if the light emission period of pulse light emission is shortened. Therefore, the power consumption of the proximity sensor can be reduced without impairing the accuracy of detecting the proximity state of the detected object 20.

(Eighth embodiment)
In the eighth embodiment of the proximity sensor with illuminance detection function of the present invention, referring to FIG. 2, the light emitted from the light emitting element 11 is infrared light. Therefore, by setting the wavelength region of light received by the illuminance sensor 13 to visible light, it is possible to prevent light emitted from the light emitting element 11 from being received by the illuminance sensor 13 and erroneously detecting ambient illuminance.

  Furthermore, in an environment where the amount of infrared light is relatively small compared to the amount of visible light, such as under a fluorescent lamp, the influence of disturbance light on the proximity sensor can be reduced. Further, when the proximity sensor is operated, it can be made inconspicuous in appearance.

(Ninth embodiment)
9 and 10 show an embodiment of the electronic apparatus of the present invention. FIG. 9 shows a mobile phone 90 as an electronic device, and FIG. 10 shows a digital camera 95 as an electronic device.

  As shown in FIG. 9, the mobile phone 90 includes the proximity sensor 91 with an illuminance detection function described in any one of the first to eighth embodiments. The mobile phone 90 has a liquid crystal monitor 92, and dimmes the LED backlight of the liquid crystal monitor 92 according to the brightness of ambient light. In addition, the cellular phone 90 reduces power consumption by controlling the display of the liquid crystal monitor 92 and the lighting of the LED backlight according to the proximity state of the detected object 20.

  As shown in FIG. 10, the digital camera 95 includes the proximity sensor 93 with an illuminance detection function described in any one of the first to eighth embodiments. The digital camera 95 has a liquid crystal monitor 94, and adjusts the LED backlight of the liquid crystal monitor 94 according to the brightness of ambient light. Further, the digital camera 95 reduces power consumption by controlling the display of the liquid crystal monitor 94 and the lighting of the LED backlight according to the proximity state of the detected object 20.

  Therefore, according to the electronic device having the above configuration, the power consumption of the electronic device can be reduced by using the proximity sensors 91 and 93 with lower power consumption.

(Tenth embodiment)
FIG. 11 shows another embodiment of the electronic apparatus of the present invention. As shown in FIG. 11, a mobile phone 100 as an electronic apparatus includes the proximity sensor 101 with an illuminance detection function described in any one of the first to eighth embodiments.

  The mobile phone 100 has a liquid crystal monitor 102 and adjusts the LED backlight of the liquid crystal monitor 102 according to the brightness of ambient light. In addition, the mobile phone 100 reduces power consumption by controlling the display of the liquid crystal monitor 102 and the lighting of the LED backlight according to the proximity state of the detected object 20 (in this embodiment, a hand). .

  In this mobile phone 100, referring to FIG. 2, the illuminance obtained from the illuminance sensor 13 when the received light amount determination circuit 22 determines that the amount of reflected light received by the light receiving element 12 exceeds the determination threshold. Ignore the information.

  That is, when the detected object 20 (hand) is close to the proximity sensor 101, the detected light 20 is prevented from being received by the illuminance sensor 13 by the detected object 20, and the illuminance sensor 13 can accurately detect the illuminance of the ambient light. Cannot be detected.

  In this way, in an electronic device that automatically adjusts the backlight of the liquid crystal monitor 102 based on the output of the illuminance sensor 13, the proximity sensor 101 is controlled to prevent inappropriate adjustment of light due to the shadow of the detected object 20. When the proximity state of the detection object 20 is detected, the illuminance information obtained from the illuminance sensor 13 is ignored.

  According to the electronic apparatus having the above-described configuration, when the received light amount determination circuit 22 determines that the amount of reflected light exceeds the determination threshold, it determines that the detected object 20 is in the proximity state to the electronic apparatus.

  For example, when the electronic device is a device that reduces power consumption by adjusting the luminance of the backlight of the liquid crystal monitor according to the ambient illuminance detected by the illuminance sensor 13, the detected object 20 is By ignoring the illuminance information obtained from the illuminance sensor 13 when the illuminance sensor 13 is in a positional relationship that prevents ambient light from being received by the illuminance sensor 13, it is possible to prevent erroneous detection that the ambient illuminance is dark. be able to.

  That is, even when the illuminance determination circuit 23 detects that the ambient illuminance is dark, if the detected object 20 is in the proximity state, the backlight brightness is not increased unnecessarily, and the power consumption of the electronic device is reduced. It can be prevented from increasing.

(Eleventh embodiment)
FIG. 12 shows another embodiment of the electronic apparatus of the present invention. As shown in FIG. 12, the electronic device includes the proximity sensor 110 with an illuminance detection function described in any one of the first to eighth embodiments.

  In this electronic device, referring to FIG. 2, when the illuminance determination circuit 23 determines that the illuminance detected by the illuminance sensor 13 exceeds the first illuminance threshold, the reflected light obtained from the light receiving element 12 is reflected. Ignore the information.

  That is, when the detected object 20 is not in the proximity state, the ambient illuminance is sufficiently bright, and the external light 112 is received by the light receiving element 12, the emitted light 111 of the light emitting element 11 is reflected by the imaginary detected object 112. Therefore, there is a possibility that a fictitious detected object 112 is erroneously detected as being nearby.

  Therefore, according to the electronic device having the above-described configuration, when the illuminance determination circuit 23 determines that the illuminance detected by the illuminance sensor 13 exceeds the first illuminance threshold value, the surroundings of the electronic device are determined to be bright.

  If the detected object 20 is not in the proximity state, the illuminance determination circuit 23 detects that the ambient illuminance is sufficiently bright even if the ambient illuminance is sufficiently bright and the light receiving element 12 receives ambient light. By ignoring the information of the reflected light obtained from the light receiving element 12, it is possible to prevent erroneous detection of the proximity state of the detected object 20.

(Twelfth embodiment)
13A and 13B show another embodiment of the proximity sensor with illuminance detection function of the present invention. As shown in FIGS. 13A and 13B, the operation flow of this proximity sensor is a combination of the first to fifth embodiments.

  That is, step S1 to step S3 show the first embodiment. Step S4, step S5, and step S11 show the third embodiment. Step S6 shows the fifth embodiment. Step S7, step S8, step S12, and step S13 show the second embodiment. Step S15, step S16, and step S10 show the fourth embodiment.

  As described above, FIGS. 13A and 13B are a combination of the first to fifth embodiments described above, and a detailed description thereof will be omitted.

(13th Embodiment)
14A and 14B show another embodiment of the proximity sensor with illuminance detection function of the present invention. As shown in FIGS. 14A and 14B, the operation flow of the proximity sensor is a combination of the first to fourth, sixth, and seventh embodiments.

  That is, step S1 to step S3 show the first embodiment. Step S4, step S5, and step S11 show the third embodiment. Step S6 and step S20 show the sixth embodiment. Step S7, Step S8, Step S12, Step S13, Step S21, and Step S22 show the second embodiment. Step S15, step S16, and step S10 show the fourth embodiment. Step S24, step S25, and step S10 show the seventh embodiment.

  As described above, FIGS. 14A and 14B are a combination of the first to fourth, sixth, and seventh embodiments, and thus detailed description thereof is omitted.

  In addition, this invention is not limited to the above-mentioned embodiment. For example, as the proximity sensor with an illuminance detection function, the first to eighth embodiments may be variously combined. Also, the electronic device may be a device other than a mobile phone or a digital camera.

DESCRIPTION OF SYMBOLS 10 Proximity sensor with illumination detection function 11 Light emitting element 12 Light receiving element 13 Illuminance sensor 14 Substrate 15 Primary mold resin 16 Secondary mold resin 20 Object to be detected 21 Control circuit 22 Light reception amount determination circuit 23 Illuminance determination circuit 24 Emission light 25 Reflected light 26 Ambient light 30 Operation timing of light emitting element and light receiving element 31 Light reception intensity of light receiving element 32 Determination threshold 33 Operation timing of illuminance sensor 34 Light reception intensity of illuminance sensor 40 Light reception intensity of illuminance sensor 41 Second illuminance threshold 42 Radiation of light emitting element Intensity 43 Determination threshold 50 Light reception intensity of illumination sensor 51 Second illumination threshold 52 Light reception intensity of light reception element 53 Determination threshold 54 Light emission intensity of light emitting element 60 Light reception intensity of illumination sensor 61 Light emission intensity of light emission element 62 Light reception intensity of light reception element 63 Determination threshold 64 Constant reference amount 70 Illuminance sensor Light reception intensity 71 Radiation intensity of light emitting element 72 Determination threshold 73 Constant reference amount 80 Light reception intensity of illuminance sensor 81 Light reception intensity of light reception element 82 Determination threshold 83 Radiation intensity of light emitting element 84 Constant reference amount 90 Mobile phone 91 With illuminance detection function Proximity sensor 93 Proximity sensor with illuminance detection function 95 Digital camera 100 Mobile phone 101 Proximity sensor with illuminance detection function 110 Proximity sensor with illuminance detection function 111 Radiated light from light emitting element 112 Fictitious detected object 113 External light

Claims (11)

A light emitting element that emits light;
A light receiving element that receives reflected light from an object to be detected of light emitted by the light emitting element;
A received light amount determination circuit that determines whether the amount of reflected light received by the light receiving element exceeds a determination threshold;
An illuminance sensor that detects the illuminance around the
An illuminance determination circuit that determines whether the illuminance detected by the illuminance sensor exceeds a first illuminance threshold;
The light emitting element stops emitting light when receiving the outputs of the received light amount determination circuit and the illuminance determination circuit and when the illuminance determination circuit determines that the illuminance exceeds a first illuminance threshold. And a control circuit for controlling the light-emitting element. The proximity sensor with illuminance detection function according to claim 1,
The control circuit is
While controlling the light emitting element so that the light emitting element emits pulses at a constant period,
The illuminance sensor so that the illuminance sensor detects illuminance when the illuminance sensor stops emitting light while the illuminance sensor emits light, while the illuminance sensor detects illuminance when the light emitting element does not emit light. Proximity sensor with illuminance detection function, characterized by controlling The proximity sensor with illuminance detection function according to claim 1 or 2,
When the illuminance determination circuit determines that the illuminance detected by the illuminance sensor is equal to or less than a second illuminance threshold smaller than the first illuminance threshold,
The control circuit controls the light receiving element to control the light emitting element so as to lower a radiation intensity of light emitted from the light emitting element, and to control the received light amount determining circuit so as to lower the determination threshold value. Proximity sensor with illuminance detection function. In the proximity sensor with an illuminance detection function according to any one of claims 1 to 3,
The illuminance determination circuit determines that the illuminance detected by the illuminance sensor is equal to or less than a second illuminance threshold smaller than the first illuminance threshold, and the received light amount determination circuit receives the light receiving element. When it is determined that the amount of reflected light exceeds the determination threshold,
The proximity sensor with an illuminance detection function, wherein the control circuit controls the light emitting element so as to shorten a light emission period of pulse light emission of the light emitting element. In the proximity sensor with an illuminance detection function according to any one of claims 1 to 4,
When the illuminance determination circuit determines that the illuminance detected by the illuminance sensor does not change within a certain time,
The proximity sensor with an illuminance detection function, wherein the control circuit controls the light emitting element so that the light emitting element stops emitting light. In the proximity sensor with an illuminance detection function according to any one of claims 1 to 5,
When the illuminance determination circuit determines that the illuminance detected by the illuminance sensor does not change within a certain time,
The control circuit controls the light receiving element to control the light emitting element so as to lower a radiation intensity of light emitted from the light emitting element, and to control the received light amount determining circuit so as to lower the determination threshold value. Proximity sensor with illuminance detection function. In the proximity sensor with an illuminance detection function according to any one of claims 1 to 6,
The illuminance determination circuit determines that the illuminance detected by the illuminance sensor does not change within a certain time, and the received light amount determination circuit determines that the amount of reflected light received by the light receiving element exceeds the determination threshold. When it is determined that
The proximity sensor with an illuminance detection function, wherein the control circuit controls the light emitting element so as to shorten a light emission period of pulse light emission of the light emitting element. In the proximity sensor with an illuminance detection function according to any one of claims 1 to 7,
The proximity sensor with an illuminance detection function, wherein the light emitted from the light emitting element is infrared light.   An electronic apparatus comprising the proximity sensor with an illuminance detection function according to claim 1. The electronic device according to claim 9,
An electronic apparatus characterized in that when the received light amount determination circuit determines that the amount of reflected light received by the light receiving element exceeds the determination threshold, the illuminance information obtained from the illuminance sensor is ignored. The electronic device according to claim 9 or 10,
An electronic apparatus characterized in that, when the illuminance determination circuit determines that the illuminance detected by the illuminance sensor exceeds a first illuminance threshold, information on reflected light obtained from the light receiving element is ignored.

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