JP7190857B2 - light sensor - Google Patents

Description

The invention disclosed herein relates to optical sensors (eg, color sensors).

Artificial lighting, such as fluorescent lamps and LED [Light Emitting Diode] lighting equipment, is a commercial power frequency (50 Hz or 60 Hz in Japan) or a frequency corresponding to this, and the phenomenon that the amount of light fluctuates periodically (so-called flicker) ). Under the influence of such flicker, there is a difference in brightness depending on the exposure timing even in photographs taken under the same environment.

Therefore, in a digital camera, the influence of flicker is suppressed by sequentially detecting the amount of ambient light at a sampling period (for example, 500 μs) sufficiently shorter than the flicker period of ambient light and performing exposure at timings when there is little difference between light and dark. It is

As an example of conventional technology related to the above, Patent Document 1 can be cited.

Japanese Patent Application Laid-Open No. 2006-115173

By the way, in an electronic device such as a smartphone, a color sensor is responsible for acquiring the amount of ambient light. However, the communication speed of the bus (approximately 100K to 1 Mbps) is not sufficient for the microcomputer to sequentially read out the output values of the color sensor, resulting in a substantial sampling cycle lengthening. Therefore, it has been difficult to perform highly accurate flicker detection.

In view of the above-described problems found by the inventors of the present application, the invention disclosed in the present specification provides an optical sensor capable of performing highly accurate flicker detection with minimal communication. aim.

The optical sensor disclosed in this specification includes a first photodetection circuit that outputs a first photodetection signal corresponding to the amount of ambient light, and a pulse of a flag signal for each peak period of the first photodetection signal. and a logic circuit for outputting (first configuration).

In the photosensor having the first configuration, the logic circuit may set a reference value of the pulse output period of the flag signal according to the measured value of the peak period (second configuration).

In the photosensor having the second configuration, the logic circuit obtains the correction value of the pulse output period from the error between the measured value of the peak period and the reference value of the pulse output period (third configuration). ).

Further, in the optical sensor having the second or third configuration, the logic circuit detects a plurality of peak positions of the first photodetection signal to obtain the actual measurement value of the peak period (fourth configuration). do it.

Further, in the photosensor having the fourth configuration, the logic circuit sets three consecutive measured values of the first photodetection signal as D[n−1], D[n], and D[n+1], If D[n−1]<D[n] and D[n]≧D[n+1] are satisfied, D[n] is the peak value of the first photodetection signal (fifth configuration) good.

Further, in the optical sensor having any one of the second to fifth configurations, the logic circuit detects when an error between the actual measurement value of the peak period and the reference value of the pulse output period reaches a predetermined upper limit, or and setting the reference value of the pulse output period when the corrected value of the pulse output period obtained from the error reaches a predetermined upper limit, or when the output signal of the external sensor satisfies a predetermined condition. A configuration (sixth configuration) for repairing is preferable.

Further, if the optical sensor having any one of the first to sixth configurations has a second photodetection circuit that outputs a second photodetection signal corresponding to the color component of the ambient light (seventh configuration) good.

In the photosensor having the seventh configuration, the logic circuit samples the first photodetection signal in a first cycle, and samples the second photodetection signal in a second cycle longer than the first cycle. A configuration (eighth configuration) is preferable.

Further, the electronic device disclosed in this specification includes a photosensor having any one of the first to eighth configurations, a microcomputer receiving the input of the flag signal from the photosensor, the photosensor and the microcomputer and a bus connecting between and (ninth configuration).

The electronic device having the ninth configuration may further include a camera, and the microcomputer may control exposure timing of the camera according to the flag signal (tenth configuration).

According to the invention disclosed in this specification, it is possible to provide an optical sensor capable of highly accurate flicker detection with minimal communication.

Diagram showing a configuration example of a color sensor Diagram showing the optical characteristics of various transmission filters A diagram showing a configuration example of a logic circuit Diagram showing outline of peak position detection operation and peak cycle correction operation Diagram showing details of peak position detection operation Flowchart showing details of peak position detection operation External view of smartphone Diagram showing an example of the internal configuration of a smartphone

<Color sensor>
FIG. 1 is a diagram showing a configuration example of a color sensor. The color sensor 1 of this configuration example is mounted on an electronic device such as a smartphone, and is a photosensor IC that detects the color components of ambient light (red component R, green component G, blue component B, and infrared component IR). It is one type, and has a first photodetection circuit 10 , a second photodetection circuit 20 , a logic circuit 30 , and an infrared cutoff filter 40 .

The first photodetection circuit 10 includes a light receiving element 11 and an AD [Analog-to-Digital] converter 12, and outputs a first photodetection signal S1 corresponding to the amount of ambient light. The first light detection circuit 10 is provided to detect flicker of ambient light caused by artificial lighting such as fluorescent lamps and LED lighting equipment.

The light receiving element 11 generates an analog current signal corresponding to the amount of ambient light incident through the infrared cut filter 40 . The AD converter 12 converts the analog current signal from the light receiving element 11 into a digital (for example, 16-bit) first photodetection signal S1.

The second photodetection circuit 20 includes light receiving elements (21R, 21G, 21B, 21IR), AD converters (22R, 22G, 22B, 22IR), and various transmission filters (23R, 23G, 23B, 23IR). and outputs second photodetection signals (S2R, S2G, S2B, S2IR) according to the color components (R, G, B, IR) of ambient light.

The light receiving element 21R generates an analog current signal corresponding to the amount of red light incident through the red light transmission filter 23R. The AD converter 22R converts the analog current signal from the light receiving element 21R into a digital (for example, 16-bit) red light detection signal S2R and outputs it. The red light transmission filter 23R has the optical characteristics indicated by the solid line in FIG. 2, and selectively transmits the red component R (wavelength of approximately 620 to 750 nm) of ambient light incident through the infrared cutoff filter 40. FIG.

The light receiving element 21G generates an analog current signal corresponding to the amount of green light incident through the green light transmission filter 23G. The AD converter 22G converts the analog current signal from the light receiving element 21G into a digital (for example, 16-bit) green light detection signal S2G and outputs it. The green light transmission filter 23G has the optical characteristics indicated by the small dashed line in FIG. 2, and selectively transmits the green component G (wavelength of approximately 495 to 570 nm) of ambient light incident through the infrared cutoff filter 40 .

The light receiving element 21B generates an analog current signal corresponding to the amount of blue light incident through the blue light transmission filter 23B. The AD converter 22B converts the analog current signal from the light receiving element 21B into a digital (for example, 16-bit) blue light detection signal S2B and outputs it. The blue light transmission filter 23B has the optical characteristics indicated by the large dashed line in FIG. 2, and selectively transmits the blue component B (wavelength of approximately 450 to 495 nm) of ambient light incident through the infrared cutoff filter 40 .

The light receiving element 21IR generates an analog current signal corresponding to the amount of infrared light incident through the infrared transmission filter 23IR. The AD converter 22IR converts the analog current signal from the light receiving element 21IR into a digital (for example, 16-bit) infrared detection signal S2IR and outputs it. The infrared transmission filter 23IR has the optical characteristics indicated by the dashed line in FIG. 2, and selectively transmits the infrared component IR (near infrared rays with a wavelength of approximately 750 to 1400 nm) included in ambient light.

The infrared cutoff filter 40 cuts off the infrared component IR contained in ambient light on the upstream side of each of the light receiving element 11, the red light transmission filter 23R, the green light transmission filter 23G, and the blue light transmission filter 23B. By providing such an infrared blocking filter 40, it is possible to accurately detect the amount of ambient light and the RGB components (and thus the color temperature).

A photodiode, a phototransistor, or the like can be preferably used as each of the light receiving elements (11, 21R, 21G, 21B, 21IR).

The logic circuit 30 detects the flicker of the ambient light by sampling the first photodetection signal S1 in the first period, while sampling the second photodetection signals (S2R, S2G, S2B, S2IR) more than the first period. Color components of the ambient light are detected by sampling at a longer second period (for example, 32 times the first period).

Note that the logic circuit 30 communicates between a microcomputer (not shown) outside the color sensor 1 and a bus signal S3 via a bus (not shown) conforming to a predetermined communication standard (such as I2C [Inter-Integrated Circuit]). It has an interface function for communication. The bus signal S3 includes, for example, measurement data regarding color components (R, G, B, IR) of ambient light.

In addition, the logic circuit 30 performs flicker detection of ambient light on the microcomputer side (furthermore, exposure timing control reflecting the detection result, etc.) at each peak cycle (=environmental flicker) of the first light detection signal S1. It also has a function of outputting a pulse of the flag signal S4 at each flicker period of light.

Below, the pulse output function of the flag signal S4 in the logic circuit 30 will be described specifically and in detail.

<Logic circuit>
FIG. 3 is a block diagram showing a configuration example of the logic circuit 30 (in particular, signal processing paths related to the pulse output function of the flag signal S4). The logic circuit 30 of this configuration example includes an integrator 31 , a peak position detector 32 , and a peak period corrector 33 .

The integrator 31 integrates the first photodetection signal S1 every predetermined sampling period Ts, thereby discretely outputting an integrated signal S31 corresponding to the amount of ambient light. It should be noted that the sampling period Ts (=corresponding to the above-described first period) should be set to a length (for example, 500 μs) equivalent to the sampling period for flicker detection in a digital camera.

The peak position detection unit 32 detects the peak position S32 of the first photodetection signal S1 from the integrated signal S31 that is sequentially acquired every sampling period Ts (details will be described later).

The peak cycle correction unit 33 outputs a pulse of the flag signal S4 for each peak cycle (=flicker cycle of ambient light) of the first photodetection signal S1 obtained from the peak position S32 of the first photodetection signal S1. At that time, the peak cycle correction unit 33 corrects the pulse output cycle of the flag signal S4 so as to match the peak cycle of the first photodetection signal S1 (details will be described later).

Note that the integrating section 31, the peak position detecting section 32, and the peak period correcting section 33 may be implemented in hardware or may be implemented in software.

<Peak position detection operation, peak cycle correction operation>
FIG. 4 is a diagram showing an overview of the peak position detection operation and peak period correction operation in the logic circuit 30, and depicts behaviors of the integration signal S31 and the flag signal S4.

The logic circuit 30 (in particular, the peak position detector 32) sequentially samples the integrated signal S31 every sampling period Ts (see black circles in the figure). Then, the logic circuit 30 detects a plurality of peak positions of the integrated signal S31 (=corresponding to the timing at which the peak value of the integrated signal S31 is detected, see white circles in the figure) from the sampling result of the integrated signal S31, and integrates An actual measurement value of the peak period (= flicker period of ambient light) of the signal S31 is obtained.

Focusing on the A section (=corresponding to the reference value setting period) in FIG. By measuring the time of , an actual measurement value T1 of the peak period is obtained. Further, by measuring the time from the second peak position (=detection timing of the peak value D2) to the third peak position (=detection timing of the peak value D3) of the integrated signal S31, the measured value T2 of the peak period is obtained. be done.

The logic circuit 30 sets the reference value T of the pulse output period of the flag signal S4 from the measured values T1 and T2 of the peak period obtained as described above. For example, the reference value T may be set to the average value (T=(T1+T2)/2) of the measured values T1 and T2 of the peak period.

In this figure, an example is given in which the reference value T of the pulse output period is calculated in the reference value setting period (=A section) set to about three times the flicker period from the start of measurement. The length is not limited to this. For example, the reference value setting period may be extended and the reference value T may be calculated from three or more measured values (T1, T2, T3, . . . ). Alternatively, the actual measurement value T1 at one point may be used as the reference value T as it is by shortening the reference value setting period.

After that, the logic circuit 30 outputs a pulse of the flag signal S4 every pulse output period set to the reference value T. FIG. Referring to this figure, the logic circuit 30 starts from the third peak position (=detection timing of the peak value D3) of the integrated signal S31, and every time the pulse output period (=reference value T) elapses, , pulse output of the flag signal S4.

In this way, the logic circuit 30 does not output the data value (for example, 16-bit value) of the integration signal S31 as it is as the bus signal S3, but instead outputs it at each peak period of the integration signal S31 (=every flicker period of ambient light). , has a function of outputting a pulse of the flag signal S4.

Therefore, the microcomputer can detect the flicker of the ambient light simply by monitoring the 1-bit flag signal S4. Therefore, the flicker can be detected with high accuracy with the minimum necessary communication regardless of the communication speed of the bus. can be done.

In addition, the logic circuit 30 continues to sequentially sample the integrated signal S31 even after the A period to obtain actual measured values of the peak period. It has a function to obtain the correction value of the period.

Focusing on the B section (=corresponding to the correction value calculation period) in FIG. By measuring the time of , an actual measurement value T3 of the peak period is obtained. Further, by measuring the time from the fourth peak position (=detection timing of the peak value D4) to the fifth peak position (=detection timing of the peak value D5) of the integrated signal S31, the measured value T4 of the peak period is obtained. be done. Further, by measuring the time from the fifth peak position (=detection timing of the peak value D5) to the sixth peak position (=detection timing of the peak value D6) of the integrated signal S31, the measured value T5 of the peak period is obtained. be done.

Furthermore, by comparing the measured values T3 to T5 of the peak period with the reference value T of the pulse output period, the error d1 (=T3-T), the error d2 (=T4-T), and the error d3 (=T5 -T) is required.

Then, the logic circuit 30 sets the correction value α of the pulse output period from the errors d1 to d3 obtained as described above. For example, the correction value α may be set to the average value of the errors d1 to d3 (α=(d1+d2+d3)/3).

In this figure, an example is given in which the correction value α of the pulse output period is calculated in the correction value calculation period (=B section) set to about three times the flicker period, but the length of the correction value calculation period is not limited to this, for example, the correction value calculation period may be extended and the correction value α may be calculated from four or more errors, or conversely, the correction value calculation period may be shortened and two points The correction value α may be calculated from the following errors.

After that, the logic circuit 30 outputs a pulse of the flag signal S4 every corrected pulse output cycle (=T+α). In line with this figure, the logic circuit 30 starts from the sixth peak position (=detection timing of the peak value D6) of the integrated signal S31, and every time the corrected pulse output period (=T+α) elapses, , the pulse output of the flag signal S4 is performed.

Further, the correction value α is successively updated by the same signal processing as described above even after the C section in the figure.

In this way, the logic circuit 30 eliminates any deviation between the peak period of the integration signal S31 (=flicker period of ambient light) and the pulse output period of the flag signal S4. , and has a function to periodically correct the pulse output period. Therefore, it is possible to improve flicker detection accuracy.

The logic circuit 30 also has a function of resetting the reference value T of the pulse output period when a predetermined resetting condition is satisfied as exception processing.

For example, when the error d (=T*-T) between the measured value T* of the peak period of the integral signal S31 and the reference value T of the pulse output period reaches a predetermined upper limit, or when the pulse corresponding to the error d When the correction value α of the output cycle reaches a predetermined upper limit value, the currently held reference value T itself is considered to be no longer appropriate. is reset.

Also, when the output signal of an external sensor provided other than the color sensor 1 satisfies a predetermined condition, the reference value T of the pulse output cycle may need to be reset. For example, when an illuminance sensor detects a change in illuminance exceeding a predetermined threshold (for example, when moving to a room with different illuminance), or when an acceleration sensor or gyro sensor detects a change in acceleration or angular velocity exceeding a predetermined threshold. (for example, when the orientation of the electronic device in which the color sensor 1 is mounted is changed), it is considered preferable to update the currently held reference value T itself. The reference value T is reset after (=A section).

FIG. 5 shows the details of the peak position detection operation in the logic circuit 30 (e.g. corresponding to the detection operation of the peak values D1 to D3 in the A section of FIG. 4 or the detection operation of the peak values D4 to D6 in the B section of FIG. 4). It is a diagram.

First, the description will focus on the first peak value D[n]. The logic circuit 30 (especially the peak position detector 32) converts three consecutive measured values of the integration signal S31 (and the first photodetection signal S1) into D[n−1], D[n], D[ n+1], D[n] is acquired as the first peak value when D[n−1]<D[n] and D[n]≧D[n+1] are satisfied.

Next, a description will be given focusing on the second peak value D[2n]. The logic circuit 30 (especially the peak position detector 32) converts three consecutive measured values of the integration signal S31 (and the first photodetection signal S1) into D[2n−1], D[2n], D[ 2n+1], D[2n] is acquired as a peak value when D[2n−1]<D[2n] and D[2n]≧D[2n+1] are satisfied.

Finally, description will be made focusing on the third peak value D[3n]. The logic circuit 30 (especially the peak position detector 32) converts three consecutive measured values of the integration signal S31 (and the first photodetection signal S1) into D[3n−1], D[3n], D[ 3n+1], D[3n] is acquired as a peak value when D[3n−1]<D[3n] and D[3n]≧D[3n+1] are satisfied.

FIG. 6 is a flow chart showing details of the peak position detection operation described in FIG. When the measurement is started, in step #1, three consecutive measured values of the integration signal S31 (and thus the first photodetection signal S1) are obtained as D[n−1], D[n], D[n+1 ], it is determined whether or not D[n−1]<D[n] and D[n]≧D[n+1] are satisfied. Here, if the determination is YES, the flow proceeds to step #2. On the other hand, if a negative determination is made, the flow returns to step #1 and the above determination processing is repeated. Note that the determination process in step #1 corresponds to the operation of detecting the first peak value D[n].

If a YES determination is made in step #1 (that is, if the first peak value D[n] is detected), in step #2, the integration signal S31 (and thus the first photodetection signal S1) D[2n−1], D[2n], and D[2n+1] are three consecutive measured values, and whether D[2n−1]<D[2n] and D[2n]≧D[2n+1] are satisfied A determination is made as to whether or not Here, if the determination is YES, the flow proceeds to step #3. On the other hand, if the determination is NO, the flow returns to step #2 and the above determination process is repeated. Note that the determination process in step #2 corresponds to the operation of detecting the second peak value D[2n].

If a YES determination is made in step #2 (that is, if the second peak value D[2n] is detected), in step #3, the integrated signal S31 (and thus the first photodetection signal S1) Let D[3n−1], D[3n], and D[3n+1] be three consecutive measurements, and let D[3n−1]<D[3n] and D[3n]≧D[3n+1] A determination is made as to whether or not the conditions are satisfied. Here, if the determination is YES, the flow proceeds to step #4. On the other hand, if a negative determination is made, the flow returns to step #3 and the above determination processing is repeated. Note that the determination process in step #3 corresponds to the operation of detecting the third peak value D[3n].

If the determination in step #3 is YES (that is, the third peak value D[3n] is detected), in step #4, the peak values D[n] and D[2n] obtained above are ] and D[3n] are used to calculate and correct the peak period (corresponding to the calculation of the reference value T and the correction value α of the pulse output period described above).

After that, the flow is returned to step #1, and the above series of signal processing is repeated.

<Application to smartphones>
FIG. 7 is an external view of a smartphone. The smartphone X is a specific example of an electronic device equipped with the color sensor 1 shown in FIG. It has a camera X2, a speaker X3 and a microphone X4, and a color sensor X10.

As described in the Background Art section, lighting fixtures Y such as fluorescent lamps and LED lighting equipment generate flicker at the commercial power supply frequency (50 Hz or 60 Hz in Japan) or a frequency corresponding thereto. Therefore, when photographing using the smartphone X in an environment illuminated by the lighting device Y, unless the exposure timing of the camera X2 is appropriately controlled, even if the photograph is taken in the same environment, it is not intended. There is a risk of causing a difference in brightness.

Therefore, the smartphone X of this configuration example is equipped with the above-mentioned color sensor 1 (see FIG. 1) as the color sensor X10, and has a function of suppressing the influence of flicker by performing exposure at a timing when there is little difference between light and dark. I have. Hereinafter, the flicker suppressing function will be described in detail while exemplifying the internal configuration of the smartphone X. FIG.

FIG. 8 is a diagram showing an internal configuration example of the smartphone X. As shown in FIG. As shown in this figure, the smartphone X includes various sensors (here, an illuminance sensor X11, an acceleration sensor X12, and a gyro sensor X13) in addition to the color sensor X10 described above.

The color sensor X10 is connected to the microcomputer X30 via a bus X20, detects color components of ambient light (red component R, green component G, blue component B, and infrared component IR), and detects the detection result ( = output the bus signal S3) to the microcomputer X30. The color sensor X10 also has a signal path for sending the aforementioned flag signal S4 to the microcomputer X30.

The illuminance sensor X11 is connected to the microcomputer X30 via the bus X20, detects ambient illuminance, and outputs the detection result to the microcomputer X30.

The acceleration sensor X12 is connected to the microcomputer X30 via the bus X20, detects acceleration of the smartphone X, and outputs the detection result to the microcomputer X30.

The gyro sensor X13 is connected to the microcomputer X30 via the bus X20, detects the angular velocity of the smartphone X, and outputs the detection result to the microcomputer X30.

The bus X20 is a signal transmission path that connects the various sensors X10 to X13 and the microcomputer X20 according to a predetermined communication standard (eg, I2C).

The microcomputer X30 is a main body that controls the operation of the smartphone X in a centralized manner. For example, focusing on the function of linking with the color sensor X10, the microcomputer X30 adjusts the backlight of the display X1 or the backlight of the camera X2 according to the color components (color temperature) of the ambient light measured by the color sensor X10. It has the ability to adjust the white balance.

The microcomputer X30 also has a function of controlling the exposure timing of the camera X2 according to the flag signal S4 input from the color sensor 10. FIG. More specifically, the microcomputer X30 performs timing control so that the camera X2 is exposed at the timing at which a pulse is generated in the flag signal S4 (=the timing at which the amount of periodically fluctuating ambient light is maximized). I do. With such a configuration, it is possible to suppress the influence of flicker and always obtain a bright image.

Further, when the illuminance sensor X11 detects a change in illuminance exceeding a predetermined threshold, or when the acceleration sensor X12 or the gyro sensor X13 detects a change in acceleration or angular velocity exceeding a predetermined threshold, the microcomputer X30 It has a function of notifying the color sensor X10 to that effect by using the bus signal S3. With such a configuration, the color sensor X10 can know the timing at which the reference value T should be updated for the pulse output period of the flag signal S4, so it is possible to improve the flicker detection accuracy.

<Other Modifications>
In addition to the above embodiments, the various technical features disclosed in this specification can be modified in various ways without departing from the gist of the technical creation. That is, the above-described embodiments should be considered as examples and not restrictive in all respects, and the technical scope of the present invention is not limited to the above-described embodiments. It is to be understood that a range and equivalents are meant to include all changes that fall within the range.

The invention disclosed in this specification can be used, for example, in mobile phones such as smartphones, tablet terminals, laptop computers, portable game machines, liquid crystal televisions, digital still cameras, digital video cameras, and the like. be.

1 Color sensor (optical sensor)
10 first photodetector circuit 11 light receiving element (photodiode)
12 AD converter 20 Second photodetector circuit 21R, 21G, 21B, 21IR Light receiving element (photodiode)
22R, 22G, 22B, 22IR AD converter 23R, 23G, 23B, 23IR Various transmission filters (R, G, B, IR)
30 Logic circuit 31 Integration unit 32 Peak position detection unit 33 Peak cycle correction unit 40 Infrared cut filter X Smart phone (electronic device)
X1 Display X2 Camera X3 Speaker X4 Microphone X10 Color sensor X11 Illuminance sensor X12 Acceleration sensor X13 Gyro sensor X20 Bus X30 Microcomputer Y Lighting equipment (flicker light source)

Claims (10)

a first photodetection circuit that outputs a first photodetection signal according to the amount of ambient light;
a logic circuit that outputs a pulse of a flag signal for each peak period of the first photodetection signal;
has
The logic circuit sets a reference value of the pulse output period of the flag signal according to the measured value of the peak period during a reference value setting period, and sets the plurality of measured values of the peak period and the pulse output during a correction value calculation period. An optical sensor , wherein a plurality of errors are obtained by comparing the reference values of the periods, respectively, and a correction value for the pulse output period is set from an average value of the plurality of errors . 2. The optical sensor according to claim 1, wherein the logic circuit outputs a pulse of the flag signal every corrected pulse output period after the correction value calculation period expires. 3. The optical sensor according to claim 1, wherein the logic circuit successively updates the correction value. The photosensor according to any one of claims 1 to 3 , wherein the logic circuit detects a plurality of peak positions of the first photodetection signal and obtains an actual measurement value of the peak period. The logic circuit defines three consecutive measured values of the first photodetection signal as D[n−1], D[n], and D[n+1], where D[n−1]<D[n] and 5. The optical sensor according to claim 4, wherein D[n] is the peak value of the first photodetection signal when D[n]≧D[n+1]. The logic circuit operates when an error between the measured value of the peak period and the reference value of the pulse output period reaches a predetermined upper limit, or when the correction value of the pulse output period obtained from the error reaches a predetermined upper limit. or when the output signal of the external sensor satisfies a predetermined condition, the reference value of the pulse output period is reset. 10. The optical sensor according to claim 1. 7. The photosensor according to claim 1, further comprising a second photodetection circuit that outputs a second photodetection signal corresponding to the color component of the ambient light. 8. The logic circuit of claim 7, wherein the logic circuit samples the first photodetection signal in a first period and samples the second photodetection signal in a second period longer than the first period. light sensor. The optical sensor according to any one of claims 1 to 8,
a microcomputer that receives the input of the flag signal from the optical sensor;
a bus connecting between the optical sensor and the microcomputer;
An electronic device comprising: further having a camera;
10. The electronic device according to claim 9, wherein the microcomputer controls exposure timing of the camera according to the flag signal.

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