WO2010110249A1 - 照度センサと、それを用いた電子機器および半導体装置 - Google Patents
照度センサと、それを用いた電子機器および半導体装置 Download PDFInfo
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Definitions
- the present invention relates to an illuminance sensor, and an electronic device and a semiconductor device using the illuminance sensor, and more particularly to an illuminance sensor including a capacitor charged by an output current of an optical sensor, and an electronic device and a semiconductor device using the illuminance sensor.
- Analog / digital converters are used in a wide variety of electronic devices. For example, it is also used for an illuminance sensor. In order to reduce power consumption, the illuminance sensor detects the brightness around a display device such as a mobile phone and a television, and adjusts the brightness of the display device itself based on the detection result.
- a display device such as a mobile phone and a television
- Patent Document 1 Japanese Unexamined Patent Application Publication No. 2008-42886 relates to an analog / digital converter already proposed by the inventors of the present application and an illuminance sensor using the same.
- the photodiode detects ambient light, converts it into current, and outputs it to an analog / digital converter.
- the analog / digital converter integrates the input current and outputs a digital value corresponding to the light level detected by the photodiode.
- the illuminance sensor of Patent Document 1 includes an optical sensor and a capacitor. Each time the charge amount of the capacitor reaches a predetermined charge amount while the capacitor is charged by the output current of the optical sensor during a predetermined charging period. The capacitor is discharged and a constant current flows out from the capacitor in response to the end of the charging period, and the photosensor is installed based on the number of times the capacitor is discharged and the time it takes to drain all the capacitor charge. Find the illuminance of the place.
- the optical sensor is formed by connecting two photodiodes having different light receiving characteristics (spectral sensitivity) in series, and outputs a current corresponding to a difference between photocurrents generated by the two photodiodes.
- Patent Document 2 JP 2009-157349 A (Patent Document 2) relates to a display device, and FIG. 3 shows a state in which an external light sensor element and a position sensor element are arranged.
- the external light sensor element receives external light incident from the front side of the liquid crystal panel shown in FIG. 1, and includes, for example, a light receiving element including a photodiode.
- the position sensor is installed in order to detect the position of the detected object on the front side opposite to the back side on which the backlight is installed.
- the position sensor includes, for example, a photodiode, and is used for detecting the position of a detection object such as a user's finger or a touch pen.
- the illuminance sensor of Patent Document 1 has a problem that the illuminance cannot be detected because the difference between the photocurrents of the two photodiodes becomes negative depending on the type of the light source. Also, depending on the type of light source, the brightness seen by the human eye may not match the measurement result of the illuminance sensor.
- a main object of the present invention is to provide an illuminance sensor capable of accurately detecting illuminance regardless of the type of light source.
- the illuminance sensor includes a first optical sensor that outputs a current corresponding to the light intensity, a second optical sensor that outputs a current corresponding to the light intensity, the light receiving area being different from the first optical sensor, , Having a first terminal for receiving an output current of the second photosensor, a second terminal and a third terminal, and the first terminal is connected to the second terminal and the third terminal based on the first control signal.
- a first switch connected to any one of the terminals, a first polarity detection circuit connected to the second terminal of the first switch for detecting the polarity of the input current, and a first photosensor
- a charge amount detection circuit connected to the output node and the third terminal of the first switch and integrating the input current to detect the charge amount, and a first control signal based on the detection result of the first polarity detection circuit Are output based on the detection result of the charge amount detection circuit. It is obtained by an arithmetic control unit for outputting a digital signal indicating the illuminance of the installation location of the light sensor.
- the polarity of the output current of the second photosensor is detected, and only the output current of the first photosensor is integrated based on the detection result, or the first and second photosensors are integrated. Select whether to integrate the sum of output currents. Therefore, the illuminance can be accurately detected regardless of the type of light source.
- FIG. 8 is a diagram showing the sum of photocurrents of the photosensors shown in FIGS.
- FIG. 8 is a diagram showing the sum of photocurrents of the photosensors shown in FIGS. FIG.
- FIG. 2 is a circuit diagram illustrating a configuration of a polarity detection circuit 4 illustrated in FIG. 1.
- FIG. 2 is a circuit diagram showing a configuration of a polarity detection circuit 5 shown in FIG. 1.
- FIG. 2 is a circuit diagram illustrating a configuration of a charge amount detection circuit illustrated in FIG. 1.
- 12 is a time chart illustrating an operation of the charge amount detection circuit illustrated in FIG. 11. It is a figure which shows the state of the switch in each operation mode shown in FIG. 14 is a time chart illustrating the operation of the illuminance sensor shown in FIGS. 14 is a time chart illustrating another operation of the illuminance sensor shown in FIGS. 1 to 13.
- FIG. FIG. 16 is a diagram showing a mobile phone provided with the illuminance sensor shown in FIGS.
- FIG. 10 is a circuit block diagram showing a configuration of a conventional illuminance sensor that is the basis of Embodiment 3. It is a circuit block diagram which shows the structure of the illumination intensity sensor by Embodiment 3 of this invention. It is a figure which shows the state of the switch in each operation mode of the illumination intensity sensor shown in FIG. FIG.
- FIG. 10 is a circuit block diagram showing a configuration of a conventional electronic device that is the basis of a fourth embodiment. It is a block diagram which shows the structure of the illumination intensity sensor by Embodiment 4 of this invention. It is a time chart which shows operation
- FIG. 1 is a circuit block diagram showing a configuration of an illuminance sensor according to Embodiment 1 of the present invention.
- the illuminance sensor includes a photoelectric converter 1, polarity detection circuits 2 and 3, and an arithmetic control circuit 5.
- the photoelectric converter 1 includes optical sensors PS1 to PS3 and switches 2 and 3.
- the optical sensor PS1 includes photodiodes PDA1 and PDB1
- the optical sensor PS2 includes photodiodes PDA2 and PDB2
- the optical sensor PS3 includes photodiodes PDA3 and PDB3.
- the cathodes of the photodiodes PDA1 to PDA3 all receive the power supply voltage VCC, and their anodes are connected to the output nodes N1 to N3 of the photosensors PS1 to PS3, respectively.
- the cathodes of the photodiodes PDB1 to PDB3 are connected to the output nodes N1 to N3, respectively, and their anodes both receive the ground voltage GND.
- the photodiode PDA includes a PN junction formed in a shallow region of the semiconductor substrate, and is formed so as to have maximum sensitivity to light in the visible light region (for example, light having a wavelength of 600 nm).
- the photodiode PDB includes a PN junction formed in a deep region of the semiconductor substrate, and is formed so as to have maximum sensitivity to light in the infrared region (for example, light having a wavelength of 860 nm). .
- FIG. 2 is a diagram showing the level of the photocurrent IA generated when the photodiode PDA of unit area is irradiated with light from a fluorescent lamp, an incandescent lamp, a halogen lamp, and a white LED (Light Emitting Diode).
- the level of the photocurrent IA generated in the photodiode PDA with respect to the light of the fluorescent lamp is set to 1
- the level of the photocurrent IA generated in the photodiode PDA with respect to the light of each light source is set as the light of the fluorescent lamp. Is shown as a ratio to the level of the photocurrent IA generated in the photodiode PDA.
- the light emission intensities of the fluorescent lamp, the incandescent lamp, the halogen lamp, and the white LED are set to have the same illuminance at the place where the photodiode PDA is installed. However, since the spectral distributions of the fluorescent lamp, incandescent lamp, halogen lamp, and white LED are different, there is a difference in the photocurrent IA.
- FIG. 3 is a diagram showing the level of the photocurrent IB generated when the light of the fluorescent lamp, incandescent lamp, halogen lamp, and white LED is irradiated onto the photodiode PDB of the unit area.
- the level of the photocurrent IA generated in the photodiode PDA with respect to the light of the fluorescent lamp is set to 1
- the level of the photocurrent IB generated in the photodiode PDB with respect to the light of each light source is set as the light of the fluorescent lamp. Is shown as a ratio to the photocurrent IA generated in the photodiode PDA.
- the emission intensity of the fluorescent lamp, the incandescent lamp, the halogen lamp, and the white LED is set so as to have the same illuminance at the place where the photodiode PDB is installed. However, since the spectral distribution of the light of the fluorescent lamp, incandescent lamp, halogen lamp, and white LED is different, there is a difference in the photocurrent IB.
- FIG. 4 is a diagram showing a layout of the photodiodes PDA1 to PDA3 and PDB1 to PDB3.
- the photodiodes PDA1 to PDA3 and PDB1 to PDB3 are arranged in a rectangular region on the surface of the semiconductor substrate.
- the photodiodes PDA1 to PDA3 and PDB3 are each divided into two photodiodes PDA1a and PDA1b; PDA2a and PDA2b; PDA3a and PDA3b; PDB3a and PDB3b.
- the photodiodes PDA2a and PDA2b are respectively arranged at the upper right and lower left corners in FIG. 4 of the rectangular area.
- the photodiodes PDA3a and PDA3b are respectively arranged at the upper left and lower right corners in FIG. 4 of the rectangular area.
- the photodiode PDA1a is disposed between the photodiodes PDA3a and PDA2a.
- the photodiode PDA1b is disposed between the photodiodes PDA2b and PDA3b.
- the photodiode PDB3a is disposed between the photodiodes PDA3a and PDA2b.
- the photodiode PDB3b is disposed between the photodiodes PDA2a and PDA3b.
- the photodiodes PDB2 and PDB1 are disposed between the photodiodes PDB3a and PDA3b.
- the area ratio of the photodiodes PDA1 and PDB1 is set to 30.5: 1.7.
- the area ratio between the photodiodes PDA2 and PDB2 is set to 25.6: 4.5.
- the area ratio of the photodiodes PDA3 and PDB3 is set to 25.6: 11.7.
- FIG. 5 is a diagram showing the levels of photocurrents IA1, IB1, and I1 that are generated when the photodiodes PDA1 and PDB1 are irradiated with light from a fluorescent lamp, an incandescent lamp, a halogen lamp, and a white LED.
- the photocurrents IA1 and IB1 are photocurrents generated in the photodiodes PDA1 and PDB1, respectively.
- the levels of the photocurrents IA1, IB1, and I1 generated with respect to the light of each light source are shown by the ratio to the photocurrent IA generated with the photodiode PDA having a unit area with respect to the light of the fluorescent lamp. Yes. For example, since the area ratio of the photodiode PDA1 is 30.5, IA1 is 30.5.
- FIG. 6 is a diagram showing the levels of photocurrents IA2, IB2, and I2 generated when the photodiodes PDA2 and PDB2 are irradiated with light from a fluorescent lamp, an incandescent lamp, a halogen lamp, and a white LED.
- the photocurrents IA2 and IB2 are photocurrents generated in the photodiodes PDA2 and PDB2, respectively.
- the levels of the photocurrents IA2, IB2, and I2 generated with respect to the light of each light source are shown as a ratio to the photocurrent IA generated with the photodiode PDA having a unit area with respect to the light of the fluorescent lamp. Yes. For example, since the area ratio of the photodiode PDA2 is 25.6, IA2 is 25.6.
- FIG. 7 is a diagram showing the levels of photocurrents IA3, IB3, and I3 generated when the photodiodes PDA3 and PDB3 are irradiated with light from a fluorescent lamp, an incandescent lamp, a halogen lamp, and a white LED.
- the photocurrents IA3 and IB3 are photocurrents generated in the photodiodes PDA3 and PDB3, respectively.
- the levels of the photocurrents IA3, IB3 and I3 generated with respect to the light of each light source are shown as a ratio to the photocurrent IA generated with the photodiode PDA having a unit area with respect to the light of the fluorescent lamp. Yes. For example, since the area ratio of the photodiode PDA3 is 25.6, IA3 is 25.6.
- FIG. 8 is a diagram showing the sum IO of the output currents I1 to I3 of the photosensors PS1 to PS3 shown in FIGS.
- the current IO is at a constant level for a constant illuminance regardless of the type of light source.
- the light source is a fluorescent lamp
- IO I1 + I2 + I3.
- the light source is an incandescent lamp
- IO I1.
- the light source is a halogen lamp
- IO I1 + I2.
- IO I1 + I2 + I3.
- the output node N1 of the optical sensor PS1 is connected to the input node 6a of the charge amount detection circuit 6 (the output node of the photoelectric converter 1).
- the output node N2 of the optical sensor PS2 is connected to the common terminal 2c of the switch 2, one switching terminal 2a of the switch 2 is connected to the input node 4a of the polarity detection circuit 4, and the other switching terminal 2b of the switch 2 is the charge amount detection circuit. 6 input nodes 6a.
- the switch 2 is controlled by a signal ⁇ 2 from the arithmetic control unit 7.
- the terminals 2a and 2c of the switch 2 become conductive, and the optical sensor PS2 and the polarity detection circuit 4 are coupled.
- the terminals 2b and 2c of the switch 2 become conductive, and the photosensor PS2 and the charge amount detection circuit 6 are coupled.
- the output node N3 of the optical sensor PS3 is connected to the common terminal 3c of the switch 3, one switching terminal 3a of the switch 3 is connected to the input node 5a of the polarity detection circuit 5, and the other switching terminal 3b of the switch 3 is the charge amount detection circuit. 6 input nodes 6a.
- the switch 3 is controlled by a signal ⁇ 3 from the arithmetic control unit 7.
- the terminals 3a and 3c of the switch 3 become conductive, and the optical sensor PS3 and the polarity detection circuit 5 are coupled.
- the terminals 3b and 3c of the switch 3 are conducted, and the photosensor PS3 and the charge amount detection circuit 6 are coupled.
- the polarity detection circuit 4 is connected to the optical sensor PS2 via the switch 2 at the start of illuminance measurement, quickly detects whether the output current of the optical sensor PS2 is positive or negative, and outputs a signal ⁇ 4 indicating the detection result To do.
- the polarity detection circuit 4 includes an operational amplifier (operational amplifier) 10, a capacitor 11, a switch 12, and a comparison circuit 13, as shown in FIG.
- the non-inverting input terminal (+ terminal) of the operational amplifier 10 receives the reference voltage VR, and its inverting input terminal ( ⁇ terminal) is connected to the input node 4 a of the polarity detection circuit 4.
- the capacitor 11 is connected between the inverting input terminal and the output terminal of the operational amplifier 10.
- the capacitance value of the capacitor 11 is set to 1 pF, for example.
- the switch 12 is controlled by a signal F2 from the arithmetic control unit 7 and is connected in parallel to the capacitor 11.
- the comparison circuit 13 compares the output voltage V2 of the operational amplifier 10 with the reference voltage 3VR / 4. When V2> 3VR / 4, the signal ⁇ 4 is set to the “H” level, and when V2 ⁇ 3VR / 4, the signal ⁇ 4. To “L” level.
- the switch 12 When the signal F2 is at “L” level, the switch 12 is turned on, the output voltage V2 of the operational amplifier 10 becomes equal to the voltage VR of the non-inverting input terminal, and the signal ⁇ 4 becomes “H” level. When the signal F2 is set to the “H” level, the switch 12 is turned off, and the capacitor 11 is charged by the output current of the photosensor PS2.
- the output voltage V2 of the operational amplifier 10 increases from the reference voltage VR to the power supply voltage VCC.
- the signal ⁇ 4 remains unchanged at the “H” level
- the signal ⁇ 2 remains unchanged at the “L” level
- the polarity detection circuit 5 is connected to the optical sensor PS3 via the switch 3 at the start of illuminance measurement, quickly detects whether the output current of the optical sensor PS3 is positive or negative, and a signal ⁇ 5 indicating the detection result. Is output.
- the polarity detection circuit 5 includes an operational amplifier 15, a capacitor 16, a switch 17, and a comparison circuit 18, as shown in FIG.
- the non-inverting input terminal (+ terminal) of the operational amplifier 15 receives the reference voltage VR, and its inverting input terminal ( ⁇ terminal) is connected to the input node 5 a of the polarity detection circuit 5.
- the capacitor 16 is connected between the inverting input terminal and the output terminal of the operational amplifier 15.
- the switch 17 is controlled by a signal F3 from the arithmetic control unit 7 and is connected in parallel to the capacitor 16.
- the comparison circuit 18 compares the output voltage V3 of the operational amplifier 15 with the reference voltage 3VR / 4. When V3> 3VR / 4, the signal ⁇ 5 is set to “H” level, and when V3 ⁇ 3VR / 4, the signal ⁇ 5 To “L” level.
- the switch 17 When the signal F3 is at “L” level, the switch 17 is turned on, the output voltage V3 of the operational amplifier 15 becomes equal to the voltage VR of the non-inverting input terminal, and the signal ⁇ 5 becomes “H” level. When the signal F3 is set to the “H” level, the switch 17 is turned off, and the capacitor 16 is charged by the output current of the photosensor PS3.
- the charge amount detection circuit 6 detects the amount of charge generated within a predetermined time in the photoelectric conversion circuit 1 and outputs signals ⁇ B and ⁇ B indicating detection results. That is, the charge amount detection circuit 6 includes an integration circuit 20, discharge circuits 23 and 25, and comparison circuits 27 and 28 as shown in FIG.
- the integrating circuit 20 includes an operational amplifier 21, a capacitor 22, and switches SW1 and SW2.
- a reference voltage VR is applied to the non-inverting input terminal of the operational amplifier 21.
- the capacitor 22 is connected between the inverting input terminal and the output terminal of the operational amplifier 21.
- the capacitance value C22 of the capacitor 22 is set to 64 pF, for example.
- the switch SW1 is connected between the input node 6a of the charge amount detection circuit 6 and the inverting input terminal of the operational amplifier 21.
- the switch SW2 is connected to the capacitor 22 in parallel.
- the discharge circuit 23 includes a capacitor 24 and switches SW3a, SW3b, SW4a, SW4b.
- the capacitance value C24 of the capacitor 24 is set to a value that is 1 ⁇ 2 times the capacitance value C22 of the capacitor 22, for example, 32 pF.
- the switch SW3a, the capacitor 24, and the switch SW3b are connected in series between the ground voltage GND line and the inverting input terminal of the operational amplifier 21.
- One terminal of the switch SW4a receives the ground voltage GND, and the other terminal is connected to one terminal of the capacitor 24.
- One terminal of the switch SW4b receives the ground voltage GND, and the other terminal is connected to the other terminal of the capacitor 24.
- the discharge circuit 25 includes a capacitor 26 and switches SW5a, SW5b, SW6a, SW6b.
- the capacitance value C26 of the capacitor 26 is set to a value 1/64 times the capacitance value C22 of the capacitor 22, for example, 1 pF.
- Switch SW5a, capacitor 26, and switch SW5b are connected in series between the node of reference voltage VR / 2 and the inverting input terminal of operational amplifier 21.
- One terminal of the switch SW6a receives the reference voltage VR / 2, and the other terminal is connected to one terminal of the capacitor 26.
- One terminal of the switch SW6b receives the reference voltage VR / 2, and the other terminal is connected to the other terminal of the capacitor 26.
- the comparison circuit 27 compares the output voltage V1 of the operational amplifier 21 with the reference voltage VR.
- V1 ⁇ VR the signal ⁇ A is set to “H” level
- V1 ⁇ VR the signal ⁇ A is set to “L” level. To do. Therefore, when the voltage between terminals of capacitor 22 becomes 0V, signal ⁇ A is raised from “L” level to “H” level, and when charging of capacitor 22 is started, signal ⁇ A is changed from “H” level to “L”. To the level.
- the comparison circuit 28 compares the output voltage V1 of the operational amplifier 21 and the reference voltage VR / 2.
- V1 ⁇ VR / 2 the signal ⁇ B is set to the “H” level, and when V1> VR / 2, the signal ⁇ B. To “L” level. Therefore, when the inter-terminal voltage of capacitor 22 is lower than VR / 2, signal ⁇ B becomes “L” level, and when the inter-terminal voltage of capacitor 22 becomes equal to or higher than VR / 2, signal ⁇ B changes from “L” level. Raised to “H” level.
- the arithmetic control unit 7 operates in synchronization with the clock signal CLK, activates the polarity detection circuits 4 and 5 in response to the measurement command signal ⁇ S given from the outside, and the polarity detection circuit 4. , 5 are controlled based on the output signals ⁇ 4, ⁇ 5.
- the arithmetic control unit 7 controls the charge amount detection circuit 6, obtains illuminance based on the output signals ⁇ A and ⁇ B of the charge amount detection circuit 6, and outputs a digital signal DO indicating the obtained illuminance.
- FIG. 12 is a time chart showing the operation of the charge amount detection circuit 6 and the arithmetic control unit 7, and FIG. 13 is a diagram showing the state of the switch SW in the operation modes A to E.
- the switch SW is set to the operation mode E (stop mode) by the arithmetic control unit 7.
- the switches SW2, SW4a, SW4b, SW6a, SW6b are turned on, and the remaining switches SW1, SW3a, SW3b, SW5a, SW5b are turned off.
- the inter-terminal voltages of the capacitors 22, 24, and 26 are reset to 0V, and the output voltage V1 of the operational amplifier 21 becomes the reference voltage VR.
- the switch SW is set to the operation mode A (charging mode of the capacitor 22) (time t1).
- the operation mode A as shown in FIG. 13, the switches SW1, SW4a, SW4b, SW6a, SW6b are turned on, and the remaining switches SW2, SW3a, SW3b, SW5a, SW5b are turned off.
- the output current of the photoelectric converter 1 flows into the capacitor 22 and charging of the capacitor 22 is started.
- the output voltage V1 of the operational amplifier 21 gradually decreases, and the output signal ⁇ A of the comparison circuit 27 falls to the “L” level.
- the output signal ⁇ B of the comparison circuit 28 is raised from the “L” level to the “H” level (time t2).
- the arithmetic control unit 7 sets the switch SW to the operation mode B (the large discharge mode of the capacitor 22) in response to the rising edge of the signal ⁇ B.
- the switches SW1, SW3a, SW3b, SW6a, SW6b are turned on, and the remaining switches SW2, SW4a, SW4b, SW5a, SW5b are turned off.
- the arithmetic control unit 7 sets the switch SW to the operation mode A again (time t3).
- the output voltage V1 of the operational amplifier 21 changes from increasing to decreasing again.
- the capacitor 24 is discharged in parallel with the charging of the capacitor 22.
- the charge stored in the capacitor 22 is discharged using the discharge circuit 23.
- the calculation control unit 7 sets the switch SW to the operation mode C (small discharge mode of the capacitor 22) when a predetermined time has elapsed from the start of charging of the capacitor 22 (time t8).
- the switches SW4a, SW4b, SW5a, SW5b are turned on, and the remaining switches SW1, SW2, SW3a, SW3b, SW6a, SW6b are turned off.
- the charging of the capacitor 22 is stopped, and a part of the electric charge accumulated in the capacitor 22 is transferred to the capacitor 26.
- the amount of charge transferred from the capacitor 22 to the capacitor 26 is 1/64 times the amount of charge of the capacitor 22 when the capacitor 26 is charged to the reference voltage VR / 2.
- the arithmetic control unit 7 sets the switch SW to the operation mode D (the discharge mode of the capacitor 26) in response to the rising edge of the next clock signal CLK (time t9). .
- the switches SW4a, SW4b, SW6a, SW6b are turned on, and the remaining switches SW1, SW2, SW3a, SW3b, SW5a, SW5b are turned off.
- stepwise small discharge is repeatedly performed by a predetermined amount using the discharge circuit 25 until there is no charge remaining in the capacitor 22.
- the small discharge period of the capacitor 22 is 128 clock periods at the longest.
- the arithmetic control unit 7 counts the number of small discharges (the number of transitions to the operation mode C) N using the discharge circuit 25. In addition, the arithmetic control unit 7 obtains the illuminance at the place where the optical sensor 42 is installed based on the number M of rising edges of the signal ⁇ B and the number N of small discharges using the discharge circuit 25, and the digital indicating the obtained illuminance.
- the signal DO is output.
- FIG. 14 is a time chart showing the operation of the illuminance sensor when the light source is a fluorescent lamp.
- charging of the capacitors 22, 11, 16 is started, the output voltages V1, V2, V3 of the operational amplifiers 21, 10, 15 start to drop from the reference voltage VR, and the output signal ⁇ A of the comparison circuit 27 is “H”. The level is lowered to the “L” level.
- the output voltage V2 of the operational amplifier 10 reaches the reference voltage 3VR / 4, the output signal ⁇ 4 of the comparison circuit 13 becomes “L” level, and the signal F2 changes from “L” level to “H” level.
- the switch 12 is turned on, and the output voltage V2 of the operational amplifier 10 becomes the reference voltage VR.
- the signal ⁇ 2 becomes “H” level, the terminals 2b and 2c of the switch 2 become conductive, and the output node N2 of the photosensor PS2 becomes the input node 6a of the charge amount detection circuit 6. Connected to. Thereby, the descending speed of the voltage V1 is increased.
- the output voltage V3 of the operational amplifier 15 reaches the reference voltage 3VR / 4
- the output signal ⁇ 5 of the comparison circuit 18 becomes “L” level
- the switch 17 is turned on, and the output voltage V3 of the operational amplifier 15 becomes the reference voltage VR.
- the terminals 3b and 3c of the switch 3 become conductive, and the output node N3 of the photosensor PS3 becomes the input node 6a of the charge amount detection circuit 6. Connected to. Thereby, the descending speed of the voltage V1 is further increased.
- the output signal ⁇ B of the comparison circuit 28 is raised from the “L” level to the “H” level.
- the switch SW is set to the operation mode B, all charges accumulated in the capacitor 22 are transferred to the capacitor 24, the voltage across the terminals of the capacitor 22 becomes 0V, and the operational amplifier 21 The output voltage V1 rises to the reference voltage VR.
- the output signal ⁇ B of the comparison circuit 28 is lowered from the “H” level to the “L” level, and the output signal ⁇ A of the comparison circuit 27 is raised from the “L” level to the “H” level.
- the arithmetic control unit 7 counts the number of rising edges of the signal ⁇ B. One rising edge of the signal ⁇ B corresponds to 30Lx.
- the switch SW In response to the rising edge of the output signal ⁇ A of the comparison circuit 27, the switch SW is set to the operation mode A again, the output voltage V1 of the operational amplifier 21 starts to decrease again, and the signal ⁇ A is decreased to the “L” level. . Thereafter, each time the output voltage V1 of the operational amplifier 21 reaches the reference voltage VR / 2, the charge stored in the capacitor 22 is discharged using the discharge circuit 23 (time t5, t6).
- the switch SW is set to the operation mode C, the charging of the capacitor 22 is stopped, and a part of the electric charge accumulated in the capacitor 22 is transferred to the capacitor 26.
- the amount of charge transferred from the capacitor 22 to the capacitor 26 is 1/64 times the amount of charge of the capacitor 22 when the capacitor 26 is charged to the reference voltage VR / 2.
- stepwise small discharge is repeatedly performed by a predetermined amount using the discharge circuit 25 until there is no charge remaining in the capacitor 22.
- the arithmetic control unit 7 counts the number N of small discharges using the discharge circuit 25, and based on the number M of rising edges of the signal ⁇ B and the number N of small discharges using the discharge circuit 25, the photoelectric converter 1 is obtained, and a digital signal DO indicating the obtained illuminance is output.
- FIG. 15 is a time chart showing the operation of the illuminance sensor when the light source is an incandescent lamp, and is a diagram compared with FIG.
- the output currents of the optical sensors PS2 and PS3 are negative, so that the output voltages V2 and V3 of the operational amplifiers 10 and 15 are supplied from the reference voltage VR.
- the light source is a white LED, as shown in FIGS. 5 to 7, since the output currents of the three photosensors PS1 to PS3 are positive, the three photosensors PS1 to PS3 are charge amount detection circuits. 6 is connected. Further, when the light source is a halogen lamp, as shown in FIGS. 5 to 7, only the output currents of the two photosensors PS1 and PS2 are positive, so that only the two photosensors PS1 and PS2 are charged. Connected to the detection circuit 6.
- the photoelectric converter 1 is composed of three photosensors PS1 to PS3, and the sum of positive currents among the output currents of the three photosensors PS1 to PS3 is constant regardless of the type of light source. It is set to be constant with respect to illuminance. Therefore, the illuminance can be accurately detected regardless of the type of light source.
- the circuit scale can be reduced as compared with the case where the charge amount detection circuit 6 is provided to each of the three photosensors PS1 to PS3.
- the charge of the capacitor 22 is transferred to the capacitor 26 little by little after the end of the charging period.
- the charge of the capacitor 22 may be discharged via the constant current circuit after the end of the charging period.
- the charge amount of the capacitor 22 can be obtained based on the constant current flowing through the constant current circuit and the time taken to discharge all the charges of the capacitor 22.
- FIG. 16 is a diagram showing a mobile phone 31 including the illuminance sensor shown in FIGS.
- a liquid crystal panel 31 for displaying an image, a plurality of keypads 32 for inputting numbers and the like, and an illuminance sensor 33 formed as an IC are provided on the surface of the mobile phone 30.
- the illuminance sensor 33 is the one shown in FIGS.
- the mobile phone 30 includes a backlight 34 for providing transmitted light to the liquid crystal panel 31, a backlight 35 for providing transmitted light to the plurality of keypads 32, and an illuminance sensor.
- a control device 36 for controlling the brightness of each of the backlights 34 and 35 based on the detection result 33 is incorporated.
- the control device 36 brightens the backlight 34 for the liquid crystal panel 31 as the illuminance increases. Further, the control device 36 turns on the backlight 35 for the keypad 32 when the illuminance is low, and turns off the backlight 35 for the keypad 32 when the illuminance is high. Thereby, the visibility of the liquid crystal panel 31 and the keypad 32 can be improved, and the power consumption can be reduced.
- the illuminance sensor 33 is applicable not only to the mobile phone 31 but also to various electric devices (liquid crystal television, personal computer, etc.) that include a liquid crystal panel and a backlight.
- the illuminance sensor 33 can be mounted on a digital still camera or a digital video camera and used for measuring the illuminance at the shooting location.
- the main purpose of the second embodiment is to provide an illuminance sensor capable of detecting a wide range of illuminance with high resolution.
- FIG. 18 is a block diagram showing a configuration of the illuminance sensor 41 according to the second embodiment.
- the illuminance sensor 41 includes an optical sensor 42, an integration circuit 20, discharge circuits 45 and 46, comparison circuits 27 and 28, a calculation unit 47, and a control unit 48.
- the optical sensor 42 includes photodiodes 43 and 44.
- the cathode of the photodiode 43 receives the power supply voltage VDD, and its anode is connected to the output node 42a.
- the cathode of the photodiode 44 is connected to the output node 42a, and the anode thereof receives the ground voltage GND.
- the photodiode 43 has photosensitivity to visible light and infrared light, and passes a current of a level corresponding to the light intensity of the incident light.
- the photodiode 44 has photosensitivity with respect to infrared rays, and passes a current of a level corresponding to the light intensity of incident light. Therefore, when light including visible light and infrared light is incident on the photodiodes 43 and 44, a difference current between the current flowing in the photodiode 43 and the current flowing in the photodiode 44 flows out from the output node 42a. Therefore, the optical sensor 42 has a sensitivity similar to that of the human eye, and outputs a current having a level corresponding to the light intensity of incident visible light.
- the switch SW1 of the integrating circuit 20 is connected between the output node 42a of the optical sensor 42 and the inverting input terminal of the operational amplifier 21.
- one terminal of the switches SW4a and SW4b receives the ground voltage GND
- one terminal of the switches SW4a and SW4b receives the reference voltage VR. In that respect, they are different. However, it is the same in that the voltage between the terminals of the capacitor 24 is reset to 0V when the switches SW4a and SW4b are turned on, and the operations of the discharge circuits 23 and 45 are the same.
- one terminal of the switches SW6a and SW6b receives the reference voltage VR / 2
- one terminal of the switches SW6a and SW6b is the reference voltage VR.
- the two are different in that they receive.
- the voltage between the terminals of the capacitor 26 is reset to 0V when the switches SW6a and SW6b are turned on, and the operations of the discharge circuits 25 and 46 are the same.
- the arithmetic unit 47 operates in synchronization with the clock signal CLK, and is a digital indicating the monitor value of illuminance based on the charge signal ⁇ C indicating the charging period of the capacitor 22 and the output signals ⁇ A and ⁇ B of the comparison circuits 27 and 28. A signal DOM and a digital signal DO indicating illuminance are output.
- the computing unit 47 measures the time by counting the number of pulses of the clock signal CLK.
- the calculation unit 47 counts the number of rising edges of the signal ⁇ B, and obtains an illuminance monitor value based on the count value.
- a digital signal DOM indicating the obtained monitor value is output.
- the calculation unit 47 obtains the charging time TC of the capacitor 22 and the number M of rising edges of the signal ⁇ B within the charging time TC (where M is a natural number) after the charging of the capacitor 22 is completed. .
- the illuminance obtained from the charge amount of the capacitor 22 during the charging time TC is M ⁇ 64 (Lx).
- the calculation unit 47 counts the number of pulses of the clock signal CLK from when the charging of the capacitor 22 is completed until the discharging of the capacitor 22 by the discharging circuit 46 is completed.
- the illuminance obtained from the charge amount of the capacitor 22 after the end of the charging time TC is N / 2 (Lx).
- the calculation unit 47 calculates the illuminance M ⁇ 64 (Lx) obtained from the charge amount of the capacitor 22 during the charging time TC, and the illuminance N / 2 (Lx) obtained from the charge amount of the capacitor 22 after the end of the charging time TC. Is added to obtain the illuminance at the place where the optical sensor 42 is installed, and a digital signal DO indicating the obtained illuminance is output.
- the control unit 48 operates in synchronization with the clock signal CLK, raises the charge signal ⁇ C to “H” level in response to the measurement command signal ⁇ S given from the outside, and then outputs it to the output signals of the comparison circuits 27 and 28. Based on this, the switches SW1, SW2, SW3a, SW3b, SW4a, SW4b are controlled to charge / discharge the capacitor 22.
- the control unit 48 counts the number of pulses of the clock signal CLK and measures time.
- the controller 48 raises the monitor value m ⁇ 64 (Lx) of the illuminance indicated by the digital signal DOM after a predetermined time T1 has elapsed after the charge signal ⁇ C has risen to the “H” level, and exceeds a predetermined value L1. It is determined whether or not.
- the control unit 48 lowers the charge signal ⁇ C to the “L” level, stops charging the capacitor 22, and SW5a, SW5b, SW6a and SW6b are controlled to discharge the capacitor 22 little by little.
- Control unit 48 finishes discharging capacitor 22 in response to signal ⁇ A rising to “H” level.
- the control unit 48 monitors the illuminance value after a predetermined time T2 (> T1) has elapsed from the start of charging the capacitor 22. It is determined whether m ⁇ 64 (Lx) exceeds a predetermined value L2. When the illuminance monitor value m ⁇ 64 (Lx) exceeds a predetermined value L2, the control unit 48 lowers the charge signal ⁇ C to the “L” level, stops charging the capacitor 22, and switches SW5a, SW5b, SW6a and SW6b are controlled to discharge the capacitor 22 little by little. Control unit 48 finishes discharging capacitor 22 in response to signal ⁇ A rising to “H” level.
- the control unit 48 When the monitor value m ⁇ 64 (Lx) of the illuminance does not exceed the predetermined value L2, the control unit 48 outputs the charge signal ⁇ C after a predetermined time T3 (> T2) has elapsed since the start of charging of the capacitor 22. It falls to the “L” level, stops charging the capacitor 22, and controls the switches SW5a, SW5b, SW6a, SW6b to discharge the capacitor 22 little by little. Control unit 48 finishes discharging capacitor 22 in response to signal ⁇ A rising to “H” level.
- FIG. 19 is a time chart showing the operation of the illuminance sensor 41 shown in FIG.
- the switch SW is set to the operation mode E (stop mode) by the control unit 48.
- the operation mode E the voltage between the terminals of the capacitors 21, 24 and 26 is reset to 0V, and the output voltage V1 of the operational amplifier 21 becomes the reference voltage VR.
- the charge signal ⁇ C is raised to “H” level, and the switch SW is set to the operation mode A (charging mode of the capacitor 22) (time t1).
- the operation mode A the output current of the optical sensor 42 flows into the capacitor 22 and charging of the capacitor 22 is started. Further, the output voltage V1 of the operational amplifier 21 gradually decreases, and the output signal ⁇ A of the comparison circuit 27 falls to the “L” level.
- Control unit 48 sets switch SW to operation mode B (large discharge mode of capacitor 22) in response to the rising edge of signal ⁇ B.
- the calculation unit 47 counts the number of rising edges of the signal ⁇ B, and based on the count value m, the illuminance monitor value m ⁇ 64 (Lx) is obtained, and a digital signal DOM indicating the obtained monitor value m ⁇ 64 (Lx) is output.
- the control unit 48 sets the switch SW to the operation mode A again (time t3).
- the output voltage V1 of the operational amplifier 21 changes from increasing to decreasing again.
- the capacitor 24 is discharged in parallel with the charging of the capacitor 22.
- the charge stored in the capacitor 22 is discharged using the discharge circuit 45.
- the controller 48 starts charging the capacitor 22 when the monitor value m ⁇ 64 (Lx) of the illuminance indicated by the digital signal DOM exceeds a predetermined value L1 when the predetermined time T1 has elapsed from the start of charging the capacitor 22. If the monitor value m ⁇ 64 (Lx) of illuminance exceeds a predetermined value L2 when a predetermined time T2 (> T1) has elapsed since the start of charging, or a predetermined time T3 (> T2) has elapsed since the start of charging of the capacitor 22 In this case, the charge signal ⁇ C is lowered to the “L” level, and the switch SW is set to the operation mode C (small discharge mode of the capacitor 22) (time t8).
- the charging of the capacitor 22 is stopped, and a part of the electric charge accumulated in the capacitor 22 is transferred to the capacitor 26.
- the amount of charge transferred from the capacitor 22 to the capacitor 26 is 1/64 times the amount of charge of the capacitor 22 when the capacitor 22 is charged to the reference voltage VR / 2.
- the control unit 48 sets the switch SW to the operation mode D (the discharge mode of the capacitor 11) (time t9).
- the operation mode D the charge transfer path from the capacitor 22 to the capacitor 26 is cut off, and the capacitor 26 is discharged. Thereafter, stepwise small discharge is repeatedly performed by a predetermined amount using the discharge circuit 46 until there is no charge remaining in the capacitor 22.
- the small discharge period of the capacitor 22 is 128 clock periods at the longest.
- Control unit 48 sets switch SW to operation mode E in response to the rising edge of signal ⁇ A. Thereby, a series of charge / discharge operations is completed.
- the calculation unit 47 counts the number of small discharges (the number of transitions to the operation mode C) N using the discharge circuit 46. In addition, the calculation unit 47 obtains the charging time TC of the capacitor 22 and the number M of rising edges of the signal ⁇ B within the charging time TC. In addition, the calculation unit 47 determines whether the light sensor 42 has the charge time TC of the capacitor 22, the number M of rising edges of the signal ⁇ B within the charge time TC, and the number N of small discharges using the discharge circuit 10. The illuminance at the installation location is obtained, and a digital signal DO indicating the obtained illuminance is output.
- the illuminance is M ⁇ 64 + N / 2 (Lx).
- the monitor value m ⁇ 64 (Lx) of illuminance is larger than a predetermined value, (M ⁇ 64 + N / 2) XTa / Tb (Lx).
- the charging time TC of the capacitor 22 is fixed to a predetermined time Ta, when the illuminance is large, M ⁇ 64 is much larger than N / 2, and the illuminance is about M ⁇ 64. As a result, the resolution of the measured value was poor.
- the charging of the capacitor 22 is completed in a short time Tb, so that M ⁇ 64 can be prevented from becoming much larger than N / 2, and the measured value Resolution can be increased.
- the charging time of the capacitor 22 is shortened, and when the illuminance is small, the charging time of the capacitor 22 is shortened, so that a wide range of illuminance can be measured.
- FIG. 20 is a flowchart showing the operations of the calculation unit 47 and the control unit 48.
- control unit 48 starts charging capacitor 22 in step S1.
- the capacitor 22 is discharged, and an illuminance monitor value m ⁇ 64 (Lx) is obtained by the calculation unit 47.
- the control unit 48 monitors the monitor value m ⁇ 64 (Lx) of illuminance based on the digital signal DOM from the calculation unit 47.
- step S2 the control unit 48 waits for a predetermined time T1 (for example, 10 ms) since the charging of the capacitor 22 is started.
- the illuminance monitor value m ⁇ 64 (Lx) is a predetermined value. It is determined whether or not L1 (for example, 65335Lx) or more.
- L1 for example, 65335Lx
- the charging of the capacitor 22 is terminated in step S4, and the capacitor 22 is subjected to a small discharge.
- step S5 the calculation unit 47 calculates the charging time TC of the capacitor 22, the number M of rising edges of the signal ⁇ B within the charging time TC, the number of small discharges using the discharging circuit 10 (the number of times of transition to the operation mode C). ) Based on N, the illuminance at the installation location of the optical sensor 42 is obtained, and a digital signal DO indicating the obtained illuminance is output. If the illuminance monitor value m ⁇ 64 (Lx) is smaller than the predetermined value L1, the process proceeds to step S6.
- step S6 the control unit 48 waits for a predetermined time T2 (for example, 80 ms) from the start of charging of the capacitor 22, and in step S3, the illuminance monitor value is set to the predetermined value L2 (for example, 8191Lx). It is determined whether or not this is the case. If the illuminance monitor value is equal to or greater than the predetermined value L2, the charging of the capacitor 22 is terminated in step S8, and the capacitor 22 is subjected to a small discharge.
- step S9 the calculation unit 47 calculates the charging time TC of the capacitor 22, the number M of rising edges of the signal ⁇ B within the charging time TC, the number of small discharges using the discharging circuit 10 (the number of transitions to the operation mode C).
- the illuminance at the installation location of the optical sensor 42 is obtained, and a digital signal DO indicating the obtained illuminance is output. If the illuminance monitor value is smaller than the predetermined value L2, the process proceeds to step S10.
- step S10 the control unit 48 waits for a predetermined time T3 (eg, 640 ms) since the charging of the capacitor 22 is started.
- step S11 the control unit 48 ends the charging of the capacitor 22, and performs a small discharge of the capacitor 22.
- step S12 the calculation unit 47 calculates the charge time TC of the capacitor 22, the number M of rising edges of the signal ⁇ B within the charge time TC, the number of small discharges using the discharge circuit 10 (the number of transitions to the operation mode C). ) Based on N, the illuminance at the installation location of the optical sensor 42 is obtained, and a digital signal DO indicating the obtained illuminance is output.
- the charging period is divided into three periods, and an illuminance monitor value m ⁇ 64 (Lx) is obtained based on the number of discharges m of the capacitor 22 every time the first and second periods are completed. If the calculated monitor value m ⁇ 64 (Lx) exceeds a predetermined value for the period, the charging of the capacitor 22 is terminated, and if not, the charging of the capacitor 22 is continued. Therefore, since the charging time of the capacitor 22 is changed according to the illuminance at the place where the optical sensor 42 is installed, a wide range of illuminance can be detected with high resolution compared to the conventional case where the charging time of the capacitor 22 is fixed.
- the charge of the capacitor 22 is transferred to the capacitor 26 little by little after the end of the charging period.
- the charge of the capacitor 22 may be discharged via the constant current circuit after the end of the charging period.
- the charge amount of the capacitor 22 can be obtained based on the constant current flowing through the constant current circuit and the time taken to discharge all the charges of the capacitor 22.
- the conventional illuminance sensor includes a photoelectric converter 51, an integration circuit 20, discharge circuits 45 and 46, comparison circuits 27 and 28, and an arithmetic control unit 52.
- the photoelectric converter 51 is connected to the node of the power supply voltage VCC and the input node 20a of the integrating circuit 20, and flows a current of a level corresponding to the illuminance.
- the photoelectric converter 51 includes, for example, a photodiode.
- the configurations and operations of the integration circuit 20, the discharge circuits 45 and 46, and the comparison circuits 27 and 28 are the same as those described with reference to FIGS.
- the arithmetic control unit 52 operates in synchronization with the clock signal CLK, controls the entire illuminance sensor in response to the measurement command signal ⁇ S given from the outside, and outputs the output signals ⁇ A and ⁇ B of the comparison circuits 27 and 28. An illuminance is obtained based on the digital signal DO indicating the obtained illuminance.
- the light sensitivity of the conventional illuminance sensor has not been fully satisfactory.
- As a method of increasing the photosensitivity of the illuminance sensor it is conceivable to increase the light receiving area of the photoelectric converter 51, but the size of the apparatus becomes large.
- the capacitance value of the capacitor 22 is decreased, the resolution of the charge amount during the charging period is increased, but the resolution of the charge amount after the charging period is lowered.
- the capacitance value of the capacitor 26 is decreased and the current value flowing out from the capacitor 22 after the charging period is decreased, the measurement time becomes longer and the variation of the measurement result increases.
- the main purpose of the third embodiment is to provide a small illuminance sensor with a short measurement time, high sensitivity, and high sensitivity.
- FIG. 22 is a circuit block diagram showing the configuration of the illuminance sensor according to the third embodiment of the present invention, and is a diagram to be compared with FIG. In FIG. 22, the illuminance sensor is different from the illuminance sensor of FIG. 21 in that the integration circuit 20 is replaced by the integration circuit 60, the discharge circuit 45 is removed, and the calculation control unit 52 is replaced by the calculation control unit 63. Is a point.
- the difference between the integration circuit 60 and the integration circuit 20 is that the capacitor 22 is replaced with capacitors 61 and 62, and switches SW7 and SW8 are added.
- the capacitor 61 is connected between the inverting input terminal and the output terminal of the operational amplifier 21.
- the capacitance value C61 of the capacitor 61 is set to 1 pF, for example.
- the switch SW8 and the capacitor 62 are connected in series between the inverting input terminal and the output terminal of the operational amplifier 21.
- the capacitance value C62 of the capacitor 62 is set to a value (for example, 63 pF) larger than the capacitance value C61 of the capacitor 61.
- the sum of the capacitance values of capacitors 61 and 62 (C61 + C62) is set to the same value as the capacitance value C22 of capacitor 22, for example.
- Switch SW7 is connected between a node of reference voltage VR and a node between switch SW8 and capacitor 62.
- the capacitance value (1 pF) of the capacitor 61 is set to 1/64 times the capacitance value (64 pF) of the capacitor 22 in FIG. 20, if the output current (that is, the illuminance) of the photoelectric converter 51 is the same as the conventional one.
- the voltage between the terminals of the capacitor 61 rises at a speed 64 times that of the capacitor 22 in FIG.
- the output current (that is, the illuminance) of the photoelectric converter 51 is 1/64 times that of the conventional case, the voltage across the terminals of the capacitor 61 increases at the same speed as the capacitor 22 in FIG. Therefore, the light sensitivity of the illuminance sensor is higher than that of the conventional illuminance sensor.
- the discharge circuit 46 includes a capacitor 26 and switches SW5a, SW5b, SW6a, SW6b.
- the capacitance value C26 of the capacitor 26 is set to a value 1/64 times the sum (C61 + C62) of the capacitance values of the capacitors 61 and 62, for example, 1 pF.
- Switch SW5a, capacitor 26, and switch SW5b are connected in series between the node of reference voltage VR / 2 and the inverting input terminal of operational amplifier 21.
- One terminal of the switch SW6a receives the reference voltage VR, and the other terminal is connected to one terminal of the capacitor 26.
- One terminal of the switch SW6b receives the reference voltage VR, and the other terminal is connected to the other terminal of the capacitor 26.
- the operation of the comparison circuits 27 and 28 is as described in FIG.
- the arithmetic control unit 63 operates in synchronization with the clock signal CLK, controls the entire illuminance sensor in response to a measurement command signal ⁇ S given from the outside, and based on output signals ⁇ A and ⁇ B of the comparison circuits 27 and 28. Illuminance is obtained and a digital signal DO indicating the obtained illuminance is output.
- the switch SW is set to the operation mode E (stop mode) by the arithmetic control unit 63 during the stop period of the illuminance sensor.
- the switches SW2, SW6a, SW6b, and SW8 are turned on, and the remaining switches SW1, SW5a, SW5b, and SW7 are turned off.
- the voltage between the terminals of the capacitors 26, 61 and 62 is reset to 0V, and the output voltage V1 of the operational amplifier 21 becomes the reference voltage VR.
- the switch SW is set to the operation mode A (charging mode for the capacitors 61 and 62) (time t1).
- the operation mode A as shown in FIG. 23, the switches SW1, SW6a, SW6b, SW7 are turned on, and the remaining switches SW2, SW5a, SW5b, SW8 are turned off.
- the output current of the photoelectric converter 51 flows into the capacitor 61, and charging of the capacitor 61 is started.
- the terminal voltage of the capacitor 62 has the same value as the terminal voltage of the capacitor 61.
- the output voltage V1 of the operational amplifier 21 gradually decreases, and the output signal ⁇ A of the comparison circuit 27 falls to the “L” level.
- Operation control unit 63 sets switch SW to operation mode B (large discharge mode of capacitor 61) in response to the rising edge of signal ⁇ B.
- operation mode B as shown in FIG. 23, the switches SW1, SW5a, SW5b, and SW7 are turned on, and the remaining switches SW2, SW6a, SW6b, and SW8 are turned off.
- the arithmetic control unit 63 sets the switch SW to the operation mode A again (time t3).
- the output voltage V1 of the operational amplifier 21 changes from increasing to decreasing again.
- the capacitor 26 is discharged in parallel with the charging of the capacitor 61.
- the charge stored in the capacitor 61 is discharged using the discharge circuit 46.
- the calculation control unit 63 sets the switch SW to the operation mode C (the small discharge mode of the capacitors 61 and 62) when a predetermined time has elapsed from the start of charging of the capacitor 61 (time t8).
- the operation mode C as shown in FIG. 23, the switches SW5a, SW5b, and SW8 are turned on, and the remaining switches SW1, SW2, SW6a, SW6b, and SW7 are turned off. Thereby, charging of the capacitor 61 is stopped, and a part of the electric charge accumulated in the capacitors 61 and 62 is transferred to the capacitor 26.
- the amount of charge transferred from the capacitors 61 and 62 to the capacitor 26 is 1/64 times the amount of charges of the capacitors 61 and 62 when the capacitors 61 and 62 are charged to the reference voltage VR / 2.
- the arithmetic control unit 63 sets the switch SW to the operation mode D (the discharge mode of the capacitor 26) (time) t9).
- the operation mode D as shown in FIG. 23, the switches SW6a, SW6b, and SW8 are turned on, and the remaining switches SW1, SW2, SW5a, SW5b, and SW7 are turned off.
- stepwise small discharge is repeatedly performed by a predetermined amount using the discharge circuit 46 until there is no charge remaining in the capacitors 61 and 62.
- the arithmetic control unit 63 counts the number of small discharges (the number of transitions to the operation mode C) N using the discharge circuit 46. Further, the arithmetic control unit 63 obtains the illuminance at the place where the photoelectric converter 51 is installed based on the number M of rising edges of the signal ⁇ B and the number N of small discharges using the discharge circuit 46, and indicates the obtained illuminance. Outputs the digital signal DO.
- the capacitor 61 is charged by the output current of the photoelectric converter 51, and the capacitor 61 is discharged every time the voltage between the terminals of the capacitor 61 reaches the reference voltage VR / 2.
- the capacitor 62 having a capacitance value larger than that of the capacitor 61 is charged to the same voltage as that of the capacitor 61.
- charges are transferred from the capacitors 61 and 62 to the capacitor 26 at a constant period, and within the charging period.
- the illuminance is obtained based on the number M of times the capacitor 61 has been discharged and the number N of times that the total charges of the capacitors 61 and 62 have been transferred to the capacitor 26 after the charging period. Therefore, the resolution of the charge amount during the charging period can be increased without reducing the resolution of the charge amount after the charging period. Therefore, it is possible to realize a small illuminance sensor with a short measurement time and high sensitivity.
- the charges of the capacitors 61 and 62 are transferred little by little to the capacitor 26 after the end of the charging period. However, after the end of the charging period, the charges of the capacitors 61 and 62 are discharged via the constant current circuit. May be. In this case, the charge amount of the capacitors 61 and 62 can be obtained based on the constant current flowing through the constant current circuit and the time taken to discharge all the charges of the capacitors 61 and 62.
- the illuminance at the place where the photoelectric converter 51 is installed is obtained based on the number of times M and N.
- the output current of the photoelectric converter 51 is integrated based on the number of times M and N. You may obtain
- the illuminance sensor operates as a charge amount detection circuit that detects the amount of charge generated by the photoelectric converter 51 within the charging period.
- a conventional electronic device 71 that is the basis of the fourth embodiment will be described.
- a conventional electronic device 71 includes a proximity sensor 72 and an illuminance sensor 73 that are disposed adjacent to each other.
- the proximity sensor 72 includes an infrared diode 74 and a photodiode 75.
- the illuminance sensor 73 includes a photodiode 76.
- the light ⁇ emitted from the infrared diode 74 is reflected by the object 77, and the reflected light enters the photodiode 75, so that the proximity sensor 72 detects the presence of the object 77.
- the illuminance sensor 73 measures the ambient brightness by detecting the ambient light AL by the photodiode 76. For example, when measuring the illuminance sensor 73, light ⁇ emitted from the infrared diode 74 is reflected by the object 77, and when the reflected light enters the photodiode 76, the photodiode 76 detects the ambient light AL and the light ⁇ .
- the illuminance sensor 73 When the illuminance sensor 73 is configured to input the current output from the photodiode 76 to the integral type analog / digital converter, the infrared diode 74 of the proximity sensor 72 disposed adjacent to the illuminance sensor 73 emits light. When the light incident on the photodiode 76 increases by the amount of the light ⁇ , the current output from the photodiode 76 increases accordingly, and the current to be integrated increases. When the illuminance sensor 73 performs the integration operation as it is, it outputs not the brightness of the ambient light AL but the result of measuring the brightness of the light combining the ambient light AL and the light ⁇ .
- the illuminance sensor 73 In order for the illuminance sensor 73 to accurately measure the brightness of the ambient light AL, while the light ⁇ is incident on the photodiode 76, the illuminance sensor 73 interrupts the operation of integrating the current output from the photodiode 76, and the infrared diode The operation of restarting the integration operation after the end of the light emission 74 is required. Further, the brightness of the ambient light AL can be measured even when only visible light is received by the photodiode 76 using an optical filter.
- Patent Document 1 relates to an analog / digital converter and an illuminance sensor using the same, and does not suggest that an illuminance sensor and an infrared reflective proximity sensor are used adjacent to each other.
- the illuminance sensor interrupts the operation of integrating the current input to the analog / digital converter if the current input to the internal analog / digital converter is cut off by a switch provided in the input unit. I can.
- the switch when the switch is composed of a transistor, when the switch is turned off, the charge input to the analog / digital converter is accumulated in the parasitic capacitance owned by the switch itself. Since the charge accumulated in the parasitic capacitance owned by is input to the analog / digital converter and the integration operation is affected, the operation of integrating the current input to the analog / digital converter may be interrupted and restarted. The problem that it is not possible arises.
- Patent Document 2 it can be estimated that if the light incident on the illuminance sensor is filtered by an optical filter, the brightness of the surroundings is accurately measured by the illuminance sensor.
- the manufacturing cost for producing the optical filter is high, and the optical filter must be used, so that it is not suitable for downsizing the entire illuminance sensor.
- the present inventor can temporarily suspend / restart the operation of integrating the input current in order to make the illuminance sensor and the infrared reflective proximity sensor adjacent to each other without using an optical filter. It has been found that it is effective to use an analog / digital converter for an illuminance sensor.
- Embodiment 4 is an illuminance sensor that can temporarily suspend / restart the operation of integrating the input current and can accurately measure ambient brightness without using an optical filter. It is to provide.
- FIG. 25 is a circuit diagram showing a configuration of the illuminance sensor 100 using the analog / digital converter according to Embodiment 4 of the present invention. Embodiment 4 of the present invention will be described below.
- the illuminance sensor 100 includes an optical sensor unit 102, a charge / discharge unit 104, and an analog / digital conversion unit 106.
- the output current I of the optical sensor unit 102 is input to the charging / discharging unit 104
- the analog signal output from the charging / discharging unit 104 is input to the analog / digital conversion unit 106
- the analog / digital conversion unit 106 is charged with the digital signal DO.
- Control signals ⁇ S1 to ⁇ S10 for controlling discharge unit 104 are output.
- the charge / discharge unit 104 and the analog / digital conversion unit 106 constitute an integral type analog / digital converter.
- the optical sensor unit 102 includes a photodiode PD, detects light by the photodiode PD, and outputs a current I corresponding to the light intensity.
- the cathode of the photodiode PD receives the power supply voltage VDD, and its anode is connected to the charge / discharge unit 104.
- the charging / discharging unit 104 includes charging circuits 108 and 110, a discharging unit 112, and a switch SW1.
- One terminal of the switch SW1 is connected to the output terminal of the charging circuit 108, the other terminal of the switch SW1 is connected to the output terminal of the charging circuit 110, and the switch SW1 opens and closes based on the control signal ⁇ S1.
- the switch SW1 When the switch SW1 is turned on, the voltage Va at the output terminal of the charging circuit 108 and the voltage Va2 at the output terminal of the charging circuit 110 become equal.
- the analog / digital conversion unit 106 converts an analog signal that is the output voltage Va of the charging circuit 108 into a digital signal DO, and outputs the digital signal DO.
- the analog / digital conversion unit 106 includes a comparison unit 118 and a control calculation unit 120.
- the charging circuit 108 is a circuit that stores electric charge according to the input current, that is, the current I output from the photodiode PD, and has one terminal connected to the inverting input terminal of the operational amplifier AMP1 and the other terminal connected to the operational amplifier AMP1.
- the charging capacitor 109 connected to the output terminal of the operational amplifier AMP1 and the constant voltage source E1 that applies the reference voltage V11 to the non-inverting input terminal of the operational amplifier AMP1.
- the charging circuit 108 is based on the control signal ⁇ S3 based on the control signal ⁇ S3 and the switch SW2 that opens and closes the input terminal to which the current I is input, that is, the anode of the photodiode PD and the inverting input terminal of the operational amplifier AMP1. And a switch SW3 for opening and closing between terminals of the charging capacitor 109.
- the charging circuit 110 is a circuit that stores charges in the charging capacitor 111 according to the charges stored in the charging capacitor 109.
- the charging circuit 110 includes a charging capacitor 111 having one terminal connected to the output terminal of the charging circuit 110, and an inverting input terminal of the operational amplifier AMP1 and the other terminal of the charging capacitor 111 based on the control signal ⁇ S4. It includes a switch SW4 that opens and closes, and an operational amplifier AMP2 whose output terminal is connected to the inverting input terminal.
- the charging circuit 110 opens and closes based on the constant voltage source E2 that applies the reference voltage V12 to the non-inverting input terminal of the operational amplifier AMP2 and the control signal ⁇ S5, and one terminal is connected to the output terminal of the charging circuit 110, and the other terminal is
- the switch SW5 connected to the output terminal of the operational amplifier AMP2 is opened and closed based on the control signal ⁇ S6, one terminal is connected to the connection point between the switch SW4 and the charging capacitor 111, and the other terminal is connected to the output terminal of the operational amplifier AMP2. Switch SW6.
- the discharge unit 112 includes a discharge circuit 114 and a discharge circuit 116. These two discharge circuits 114 and 116 are connected to the charging circuits 108 and 110. For this reason, the discharge part 112 can discharge the electric charge stored in the charging circuits 108 and 110. However, in the fourth embodiment, the discharging unit 112 is configured to discharge the charge stored in the charging circuit 108.
- the discharge circuit 114 is a circuit that discharges the charge stored in the charging circuit 108 every time the charging amount of the charging circuit 108 reaches a predetermined threshold value.
- Discharging circuit 114 includes a discharging capacitor 115 having a capacitance value 1 / m (m> 1) of the capacitance value of charging capacitor 109, and switches SW7a, SW7b, SW8a, and SW8b.
- Switch SW7a opens and closes between one terminal of discharging capacitor 115 and the ground voltage node based on control signal ⁇ S7.
- the switch SWb opens and closes between the other terminal of the discharging capacitor 115 and the inverting input terminal of the operational amplifier AMP1 based on the control signal ⁇ S7.
- Switch SW8a opens and closes between one terminal of discharging capacitor 115 and a node of reference voltage V11 based on control signal ⁇ S8.
- Switch SW8b opens and closes between the other terminal of discharging capacitor 115 and the node of reference voltage V11 based on control signal ⁇ S8.
- the discharge circuit 116 uses a discharge capacitor 117 having a capacity smaller than that of the discharge capacitor 115 of the discharge circuit 114, and gradually changes the charge remaining in the charge circuit 108 by a predetermined amount until it reaches a predetermined value. It is a means for discharging. Further, the discharge circuit 116 generates a discharge capacitor 117 having a capacity of 1 / n (n> m) of the charge capacitor 109 and a reference voltage V13 which is 1 / k (k> 1) of the reference voltage V11.
- the discharge circuit 116 includes switches SW9a, SW9b, SW10a, SW10b.
- the switch SW9a opens and closes between one terminal of the discharging capacitor 117 and the positive terminal of the constant voltage source E3 based on the control signal ⁇ S9.
- the switch SW9b opens and closes between the other terminal of the discharging capacitor 117 and the inverting input terminal of the operational amplifier AMP1 based on the control signal ⁇ S9.
- Switch SW10a opens and closes between one terminal of discharging capacitor 117 and the node of reference voltage V11 based on control signal ⁇ S10.
- Switch SW10b opens and closes between the other terminal of discharging capacitor 117 and the node of reference voltage V11 based on control signal ⁇ S10.
- the comparison unit 118 compares the output voltage Va of the charging circuit 108 with each of the reference voltages V14 and V15.
- the comparison unit 118 includes a constant voltage source E4 that generates a reference voltage V14, a constant voltage source E5 that generates a reference voltage V15, a non-inverting input terminal that receives the output voltage Va of the charging circuit 108, and an inverting input terminal that is a constant voltage.
- the comparator CMP1 receives the output voltage V14 of the source E4, and the comparator CMP2 receives the output voltage Va of the charging circuit 108 at the inverting input terminal and receives the output voltage V15 of the constant voltage source E5.
- Control calculation unit 120 receives clock signal CLK, command signal IS, and output signals ⁇ A and ⁇ B of comparators CMP1 and CMP2, generates control signals ⁇ S1 to ⁇ S10 based on these signals, and charging circuits 108 and 110 and discharging circuit The charge / discharge operation of 114 and 116 is controlled.
- control calculation unit 120 calculates the total charge amount of the charging circuit 108 from the number of times the charging capacitor 109 is discharged by the discharging circuits 114 and 116, and outputs a digital signal DO indicating the calculation result.
- the clock signal CLK and the command signal IS are input from, for example, a microcomputer (not shown).
- the control calculation unit 120 and a microcomputer are assumed to be separate, but the control calculation unit 120 may be built in the microcomputer.
- Each of the switches SW1 to SW10 is composed of an N channel type or P channel type MOS transistor. Control signals ⁇ S1 to ⁇ S10 are applied to the gate electrodes of the switches SW1 to SW10, respectively. Note that each of the switches SW1 to SW10 may be formed of an NPN-type or PNP-type bipolar transistor, and control signals ⁇ S1 to S10 may be applied to their base electrodes, respectively.
- the reference voltages V11, V12, and V14 are set to the same voltage VR.
- the reference voltages V13 and V5 are set to the same voltage VR / 2.
- the capacitance values of charging capacitors 109 and 111 are set to the same value.
- the capacitance values of charging capacitors 109 and 111 are both set to 64 pF
- the capacitance value of discharging capacitor 115 is set to 32 pF
- the capacitance value of discharging capacitor 117 is set to 1 pF. Since the capacitance values of the charging capacitors 109 and 111 are equal, when the switch SW1 is turned on, a charge equal to the charge stored in the charging capacitor 109 is stored in the charging capacitor 111.
- discharge circuits 114 and 116 two discharge paths (discharge circuits 114 and 116) are provided, the capacitance value of the discharge capacitor 115 of the discharge circuit 114 is set to 32 pF, for example, and the capacitance value of the discharge capacitor 117 of the discharge circuit 116 is set to 1 pF, for example. If it is set and the capacitance values of the discharge capacitors 114 and 117 are changed by about one digit, a discharge circuit 114 that discharges a large amount of charge stored in the charge capacitor 109 at a time and a discharge circuit 116 that discharges a small amount at a time. Can be used according to the purpose.
- the charge amount of the charging circuit 108 is first roughly measured by discharging by the discharging circuit 114, and after the input of the current I to the charging circuit 108 is finished, the charging capacitor 109 As a result of discharging the remaining charge in the discharge circuit 116 and measuring the amount of charge finely, the accuracy of the illuminance sensor 100 can be improved without requiring complicated external control as compared with the case where only one discharge circuit is provided. Measurement time can be shortened.
- FIG. 26 is a time chart showing an example of the charging / discharging operation in the charging / discharging unit 104.
- 26 shows the transition of the output voltage Va of the charging circuit 108 and the output voltage Va2 of the charging circuit 110 with respect to the elapse of time t.
- the lower stage of FIG. 26 shows the clock with respect to the elapse of time t.
- the signal CLK, the output signals ⁇ A and ⁇ B of the comparators CMP1 and CMP2, the command signal IS, and the transition of the operation mode are shown.
- the command signal IS is a signal input to the control calculation unit 120 from a microcomputer (not shown), and is used to control the integration operation of the illuminance sensor 100. For example, when the command signal IS becomes “H” level, the illuminance sensor 100 stops the integration operation, and when the command signal IS changes from “H” level to “L” level, the illuminance sensor 100 resumes the integration operation.
- the period Tm1 indicates an input period of the current I to the charging circuit 108.
- the illuminance sensor 100 inputs the current I to the charging circuit 108 and charges the charging capacitor 109. When a certain amount of electric charge is stored in the charging capacitor 109, the illuminance sensor 100 uses the discharging circuit 114 to discharge the electric charge stored in the charging capacitor 109 and resume charging. Further, the integration operation of the illuminance sensor 100 is controlled by the command signal IS.
- the period Tm1 and the input of the current I to the charging circuit 108 are terminated when the number of pulses of the clock signal CLK from a microcomputer (not shown) reaches a predetermined count number. However, when the illuminance sensor 100 interrupts the integration operation, the pulse counting of the clock signal CLK is interrupted. After the period Tm1 ends, the illuminance sensor 100 shifts to the period Tm2.
- the period Tm2 is a period during which the charge stored in the charging circuit 108 is measured at the end of the period Tm1.
- the illuminance sensor 100 ends the input of the current I to the charging circuit 108, and the electric charge stored in the charging capacitor 109 is discharged in small increments by the discharging circuit 116. By repeating the discharge by the discharge circuit 116, the amount of charge stored in the charging capacitor 109 when the input of the current I to the charging circuit 108 is completed is measured. When all the charge remaining in the charging capacitor 109 is discharged, the period Tm2 ends.
- FIG. 27 is a table showing the state of the switch SW in the operation modes A to G.
- the “capacitor 109 charging mode” in the operation content column of FIG. 27 charges are stored in the charging capacitor 109 in accordance with the current I output from the photodiode PD.
- the “large discharge mode of the capacitor 109” the charge stored in the charging capacitor 109 is moved to the discharging capacitor 115 within one clock of the clock signal CLK.
- the electric charge stored in the charging capacitor 109 is moved to the discharging capacitor 117 within one clock of the clock signal CLK by the amount of electric charge that can be stored in the discharging capacitor 117. .
- the electric charge transferred to the discharging capacitor 117 by the “small discharging mode of the capacitor 109” is discharged within one clock of the clock signal CLK.
- the illuminance sensor 100 In “standby mode”, the illuminance sensor 100 is powered on and waits for various instructions from a microcomputer (not shown). In the “integration interruption mode”, the operation of integrating the current I output from the photodiode PD is temporarily interrupted. In the “integration restart mode”, the illuminance sensor 100 temporarily stops the integration operation in the “integration interruption mode” and then performs the integration operation again.
- Control calculation unit 120 sends control signals ⁇ S 1 to ⁇ S 10 to charging / discharging unit 104.
- the switches SW1, SW2, SW4, SW7a, SW7b, SW9a, and SW9b are turned off. Further, the switches SW3, SW5, SW6, SW8a, SW8b, SW10a, SW10b are turned on. At this time, the switches SW1 and SW4 may be turned on and the switches SW5 and SW6 may be turned off.
- the path through which the current I output from the photodiode PD is input to the charging circuit 108 is cut off, and the charges of the charging capacitors 109 and 111 and the discharging capacitors 115 and 117 are both discharged.
- the output voltage Va of the charging circuit 108 becomes equal to the reference voltage V11 (reference voltage V14). Since output voltage Va of charging circuit 108 is equal to reference voltage V14, output signal ⁇ A of comparator CMP1 is at “H” level.
- the control calculation unit 120 causes the illuminance sensor 100 to measure ambient brightness, that is, the operation mode A, that is, charging.
- the control signals ⁇ S1 to ⁇ S10 for instructing the charging mode of the capacitor 109 are sent.
- the illuminance sensor 100 starts measuring ambient brightness.
- the illuminance sensor 100 turns on the switch SW2, inputs the current I output from the photodiode PD to the charging circuit 108, and shifts to the period Tm1.
- the switches SW1, SW2, SW6, SW8a, SW8b, SW10a, and SW10b are turned on. Further, the switches SW3, SW4, SW5, SW7a, SW7b, SW9a, SW9b are turned off. In the operation mode A, the states of the switches SW1, SW2, SW3, and SW5 are changed from the operation mode E.
- the path through which the current I output from the photodiode PD is input to the charging circuit 108 is conducted, and charging of the charging capacitor 109 is started.
- the output voltage Va of the charging circuit 108 decreases as the charging capacitor 109 is charged.
- the switch SW1 since the switch SW1 is on, the output voltage Va of the charging circuit 108 and the output voltage Va2 of the charging circuit 110 are equal.
- the capacitances of the charging capacitor 109 and the charging capacitor 111 are equal to 64 pF, both capacitors hold the same charge.
- the charging capacitor 109 is charged and the discharging capacitors 115 and 117 are discharged.
- the control calculation unit 120 transmits control signals ⁇ S1 to ⁇ S10 instructing the operation mode B, that is, the large discharge mode of the charging capacitor 109, and further counts the number of transitions to the operation mode B.
- the switches SW1, SW2, SW6, SW7a, SW7b, SW10a, and SW10b are turned on. Further, the switches SW3, SW4, SW5, SW8a, SW8b, SW9a, SW9b are turned off.
- the states of the switches SW7a, SW7b, SW8a, and SW8b are changed from the operation mode A.
- the charge transfer path from the charging capacitor 109 to the discharging capacitor 115 is conducted, and the accumulated charge in the charging capacitor 109 is transferred to the discharging capacitor 115. Since the switch SW1 is on, the output voltage Va2 of the charging circuit 110 changes according to the output voltage Va of the charging circuit 108. Note that the output signal ⁇ B of the comparator CMP2 becomes “L” level when the output voltage Va of the charging circuit 108 becomes equal to or higher than the reference voltage V15.
- the discharging capacitor 115 can store the same amount of charge as the charging capacitor 109.
- the charge accumulated in the charging capacitor 109 is transferred to the discharging capacitor 115 by 32 pF ⁇ VR. Therefore, in the operation mode B starting from time t2, the output voltage Va of the charging circuit 108 is Increase by a certain value. Note that the movement of charges from the charging capacitor 109 to the discharging capacitor 115 is completed in a very short time compared to the charging time of the charging capacitor 109 in the operation mode A.
- the operation mode B the input of the current I output from the optical sensor unit 102, that is, the charging of the charging capacitor 109 is continued.
- the output voltage Va of the charging circuit 108 at the start of the operation mode B becomes the reference voltage V15, that is, VR / 2 or less. Therefore, the output signal ⁇ A of the comparator CMP1 is continuously maintained at the “L” level.
- the operation mode B ends with one clock of the clock signal CLK.
- the control calculation unit 120 ends the operation mode B and again applies the control signals ⁇ S1 to ⁇ S10 instructing the operation mode A to the charge / discharge unit 104. To send.
- the control calculation unit 120 sends out the operation signals F, that is, the control signals ⁇ S1 to S10 instructing the integration interruption mode.
- the switches SW1, SW4, SW5, SW7a, SW7b, SW9a, and SW9b are turned off. Further, the switches SW2, SW3, SW6, SW8a, SW8b, SW10a, SW10b are turned on. In the operation mode F, the states of the switches SW1 and SW3 are changed from the operation mode A.
- the output terminal of the charging circuit 108 and the output terminal of the charging circuit 110 are disconnected by the switch SW1, and the charging circuit 110 is further disconnected from the other circuits by the switches SW1 and SW4. Therefore, the output voltage Va2 of the charging circuit 110 is maintained at the voltage at the start of the operation mode F.
- the output voltage Va2 of the charging circuit 110 is also the voltage of the output voltage Va of the charging circuit 108 at the start of the operation mode F.
- the output voltage Va of the charging circuit 108 is equal to the reference voltage V11 (reference voltage V14) because the switch SW3 is turned on, and the output signal ⁇ A of the comparator CMP1 becomes “H” level.
- the illuminance sensor 100 interrupts the operation of integrating the current I output from the optical sensor unit 102. Further, since the switches SW2 and SW3 are turned on, it is possible to prevent charges from being accumulated in the parasitic capacitance owned by the switch itself.
- the control calculation unit 120 sends out the control signals ⁇ S1 to ⁇ S10 instructing the operation mode G, that is, the integration resumption mode, in order to resume the interrupted integration operation.
- the switches SW1, SW3, SW6, SW7a, SW7b, SW9a, and SW9b are turned off. Further, the switches SW2, SW4, SW5, SW8a, SW8b, SW10a, SW10b are turned on. In the operation mode G, the states of the switches SW3, SW4, SW5, and SW6 are changed from the operation mode F.
- the charge stored in the charging capacitor 111 is transferred to the charging capacitor 109.
- the output voltage Va2 of the charging circuit 110 is maintained at the output voltage Va of the charging circuit 108 at the start of the operation mode F. Therefore, the charge held in the charging capacitor 111 can be transferred to the charging capacitor 109. it can. As a result, the output voltage Va of the charging circuit 108 can be returned to the output voltage Va of the charging circuit 108 immediately before the illuminance sensor 100 interrupts the integration operation.
- the switch SW5 since the switch SW5 is on, the output voltage Va2 of the charging circuit 110 is equal to the reference voltage V11 (reference voltage V14). Further, since the switch SW2 is turned on and the switch SW3 is turned off, the charging of the charging capacitor 109 is resumed.
- the charge transfer from the charging capacitor 111 to the charging capacitor 109 in the operation mode G is completed in a very short time compared to the charging time in the operation mode A.
- the operation mode G ends in one clock period of the clock signal CLK.
- the operation mode B is entered, and the period when the count value of the pulse of the clock signal CLK to the illuminance sensor 100 reaches a predetermined value.
- Tm1 the operation mode C is entered. Otherwise, the operation mode A is entered.
- the switch SW1 When the operation mode A is entered after the operation mode G ends at time t6, the switch SW1 is turned on, so that the output voltage Va2 of the charging circuit 110 becomes equal to the output voltage Va of the charging circuit 108. Even when the operation mode B or the operation mode C is entered after the operation mode G is completed, the switch SW1 is turned on, so that the output voltage Va2 of the charging circuit 110 becomes equal to the output voltage Va of the charging circuit 108.
- the illuminance sensor 100 After the illuminance sensor 100 is shifted to the period Tm1 at time t7, when the count value of the pulse of the clock signal CLK in the operation mode A, the operation mode B, and the operation mode G reaches a predetermined value, the illuminance sensor 100 is in the period Tm1. To period Tm2.
- the control calculation unit 120 When entering the period Tm2, the control calculation unit 120 sends the control signals ⁇ S1 to ⁇ S10 instructing the operation mode C, that is, the small discharge mode of the charging capacitor 109, to the charge / discharge unit 104, and further determines the number of transitions to the operation mode C. Count.
- the switches SW1, SW6, SW8a, SW8b, SW9a, SW9b are turned on. Further, the switches SW2, SW3, SW4, SW5, SW7a, SW7b, SW10a, SW10b are turned off. In the operation mode C, the states of the switches SW2, SW9a, SW9b, SW10a, and SW10b are changed from those in the operation mode A.
- the path through which the current I output from the photodiode PD is input to the charging circuit 108 is blocked, and the charge transfer path from the charging capacitor 109 to the discharging capacitor 117 is turned on. Is stored in the discharge capacitor 117 by a certain amount.
- the charge held in the charging capacitor 109 moves to the discharging capacitor 117 by 1 pF ⁇ VR / 2, and the output voltage Va of the charging circuit 108 increases by that amount. Note that the movement of charges from the charging capacitor 109 to the discharging capacitor 117 is completed in a very short time compared to the charging time of the charging capacitor 109 in the operation mode A.
- control calculation unit 120 After the operation mode C is started at time t8, when the next clock signal CLK rises, the control calculation unit 120 operates in the operation mode D, that is, in order to discharge the charge transferred from the charging capacitor 109 to the discharging capacitor 117. Control signals ⁇ S 1 to ⁇ S 10 instructing the discharge mode of discharge capacitor 117 are sent to charging / discharging unit 104.
- the switches SW1, SW6, SW8a, SW8b, SW10a, and SW10b are turned on. Further, the switches SW2, SW3, SW4, SW5, SW7a, SW7b, SW9a, SW9b are turned off. In the operation mode D, the states of the switches SW9a, SW9b, SW10a, and SW10b are changed from the operation mode C.
- the discharge mode 116 is used to repeatedly discharge the operation mode C and the operation mode D by a predetermined amount until the charge remaining in the charging circuit 108 reaches a predetermined value.
- the period Tm2 one clock period of the clock signal CLK is required for the charge transfer from the charging capacitor 109 to the discharging capacitor 117, and one clock period of the clock signal CLK is required for discharging the charge of the discharging capacitor 117. Cost. Since the capacitance value of the discharging capacitor 117 is 1/64 of the capacitance value of the charging capacitor 109, the period Tm2 is 128 clock periods at the longest.
- the control calculation unit 120 transmits control signals ⁇ S1 to ⁇ S10 instructing the operation mode E to end the period Tm2. . Thereby, the series of charge / discharge operations is completed.
- the control calculation unit 120 calculates the number of discharges of the charging capacitor 109 using the discharge circuit 114 and the discharge circuit 116 from the number of times of transition to the operation mode B and the number of times of transition to the operation mode C.
- the total charge amount of the charging circuit 108 is calculated.
- the control calculation unit 120 calculates the brightness around the illuminance sensor 100 from the total charge amount of the charging circuit 108 and outputs a digital signal DO.
- the illuminance sensor 100 waits until various instructions are given from a microcomputer (not shown) connected to the illuminance sensor 100, and a measurement command is received. When given, the operation proceeds to the period Tm1, and the above-described operation is performed thereafter.
- the charging circuit 108 interrupts the integration operation when the integration operation resumes. Since the charging circuit 108 resumes the integration operation from the state immediately before the integration operation is interrupted, the illuminance sensor 100 can temporarily interrupt / restart the integration operation. Therefore, the illuminance sensor 100 can accurately measure the ambient brightness.
- the charging circuit 110 is used alone. However, a plurality of charging circuits 110 are connected in parallel, and the sum of the capacitance values of the plurality of charging capacitors 111 becomes the capacitance value of the charging capacitor 109. You may make it equal.
- FIG. 28 is a diagram showing an example of the configuration of the electronic device 200 according to the present invention.
- the configuration of the electronic device 200 will be described with reference to FIG.
- the electronic device 200 includes an input device 202 and a lighting device 204.
- the input device 202 is used for operating the electronic device 200.
- the input device 202 includes, for example, a plurality of buttons. When the button is pressed, the switch is turned on, and when the button is released, the switch is turned off.
- the input device 202 may be a touch panel or a voice input device.
- the lighting device 204 serves as a display device for the electronic device 200. For example, when the input device 202 is operated and a signal is input, the lighting device 204 displays an input result.
- FIG. 29 is a block diagram illustrating a configuration of the lighting device 204.
- the illumination device 204 includes an illumination unit 206, a light receiving unit 208, and a microcomputer 211.
- the illumination unit 206 includes a light source element such as an LED or an organic EL. The lighting / extinguishing of these light source elements is controlled by the microcomputer 211.
- the light receiving unit 208 includes a semiconductor device in which the illuminance sensor 100 and the infrared reflective proximity sensor 212 are formed on one semiconductor substrate.
- the light receiving unit 208 receives ambient light, and also receives light reflected from an object emitted from the infrared diode of the proximity sensor 212.
- the illuminance sensor 100 measures ambient brightness and sends a signal indicating the measurement result to the microcomputer 211.
- the proximity sensor 212 detects whether or not an object is in proximity to the lighting device 204 and sends a signal indicating the detection result to the microcomputer 211.
- the microcomputer 211 controls lighting of the illumination unit 206 based on the measurement result of the illuminance sensor 100 and the detection result of the proximity sensor 212.
- the microcomputer 211 controls the illuminance sensor 100 and the proximity sensor 212.
- the microcomputer 211 sends a measurement command to the illuminance sensor 100 to start measuring ambient brightness. Further, the command signal IS is transmitted to the illuminance sensor 100 at, for example, “L” level.
- the microcomputer 211 sends a detection command DS to the proximity sensor 212 in order to detect an object near the lighting device 204.
- a detection command DS is sent to the proximity sensor 212.
- the command signal IS is changed from “L” level to “H” level, for example.
- the illuminance sensor 100 may send the detection command DS to the proximity sensor 212 after the microcomputer 211 changes the command signal IS from the “L” level to the “H” level.
- the illuminance sensor 100 performs the above-described integration interruption operation in response to the command signal IS transitioning from the “L” level to the “H” level. Further, the proximity sensor 212 detects the presence or absence of an object near the lighting device 204 in response to the detection command DS, and sends a signal indicating the detection result to the microcomputer 211.
- the microcomputer 211 ends the detection of the object near the lighting device 204 by the proximity sensor 212 in a certain time.
- the microcomputer 211 causes the command signal IS sent to the illuminance sensor 100 to transition from the “H” level to the “L” level. Therefore, the proximity sensor 212 operates only when the illuminance sensor 100 is not performing the integration operation, and the illuminance sensor 100 does not perform the integration operation while the proximity sensor 212 is operating.
- the illuminance sensor 100 restarts the integration operation described above in response to the command signal IS changing from “L” level to “H” level, for example.
- the illuminance sensor 100 then sends the measurement result to the microcomputer 211 as a digital signal DO when measurement of ambient brightness is completed.
- the microcomputer 211 controls lighting of the illumination unit 206 based on the measurement result of the illuminance sensor 100 and the detection result of the proximity sensor 212. For example, the microcomputer 211 adjusts the brightness of the illumination unit 206 according to the ambient brightness, and darkens the illumination unit 206 when the proximity sensor 212 detects the presence of an object near the illumination device 204. By repeating the above operation, the illumination unit 206 is always kept at an optimal brightness.
- the electronic device 200 accurately measures ambient brightness even when the illuminance sensor 100 and the proximity sensor 212 are arranged adjacent to each other, and the brightness of the illumination unit 206 is measured by the illuminance sensor 100. It can always be adjusted to the optimum brightness from the result and the detection result of the proximity sensor 212.
- the illuminance sensor 100 and the proximity sensor 212 are formed on one semiconductor substrate, a semiconductor device having functions of a proximity sensor and an illuminance sensor can be provided on a single chip. Since the illuminance sensor 100 of the present invention does not use an optical filter, it is suitable for downsizing and can be easily incorporated on the same semiconductor chip as the infrared reflective proximity sensor 212. By using a semiconductor device in which the infrared reflective proximity sensor 212 and the illuminance sensor 100 according to the present invention are incorporated in one chip, it is possible to contribute to miniaturization of the entire electronic device.
- the illuminance sensor 100 can be used not only adjacent to the infrared reflection type proximity sensor 212 but also to be integrated with various light emitting elements when the light emitting elements are turned on.
- the ambient brightness can be accurately measured by interrupting and restarting the integration operation when the light is extinguished.
- the illuminance sensor 100 and the semiconductor device according to the present invention are incorporated into a lighting device such as a display device or a keypad backlight, and the lighting device 204 according to the present invention is, for example, a mobile phone or a portable game machine. Incorporation into electronic equipment can greatly contribute to power consumption reduction.
- the semiconductor device according to the present invention in which an infrared reflection type proximity sensor and an illuminance sensor are formed on one semiconductor substrate is mounted on an electronic device having a touch panel mounted on the display device, it can greatly contribute to downsizing of the electronic device. .
- the analog / digital converter of the present invention can suspend and resume the integration operation of the current input to the analog / digital converter.
- an illuminance sensor using this is disposed adjacent to an infrared reflective proximity sensor, ambient brightness can be accurately measured without an optical filter.
- an optical filter since an optical filter is not used, the manufacturing cost can be suppressed, and since it is advantageous for miniaturization, industrial applicability is extremely high.
- the illuminance sensor according to the present invention and an infrared reflective proximity sensor are incorporated on a single semiconductor substrate, it can contribute to downsizing of the entire electronic device, and thus can be used industrially. The nature is extremely high.
Abstract
Description
図1は、この発明の実施の形態1による照度センサの構成を示す回路ブロック図である。図1において、この照度センサは、光電変換器1、極性検出回路2,3、および演算制御回路5を備え、光電変換器1は光センサPS1~PS3およびスイッチ2,3を含む。
特許文献1の照度センサでは、キャパシタの充電期間が一定時間に固定されていたので、明状態から暗状態まで広範囲の照度を高い分解能で検出することはできなかった。
従来の照度センサは、図21に示すように、光電変換器51、積分回路20、放電回路45,46、比較回路27,28、および演算制御部52を備える。光電変換器51は、電源電圧VCCのノードと積分回路20の入力ノード20aに接続され、照度に応じたレベルの電流を流す。光電変換器51は、たとえば光ダイオードを含む。
実施の形態4の理解を容易にするために、まず実施の形態4の基礎となる従来の電子機器71について説明する。図24に示すように、従来の電子機器71は、互いに隣接して配置された近接センサ72と照度センサ73を備える。近接センサ72は、赤外線ダイオード74と光ダイオード75を含む。照度センサ73は、光ダイオード76を含む。
Claims (22)
- 光強度に応じた電流を出力する第1の光センサと、
前記第1の光センサと受光面積が異なり、光強度に応じた電流を出力する第2の光センサと、
前記第2の光センサの出力電流を受ける第1の端子と、第2および第3の端子とを有し、第1の制御信号に基づいて第1の端子を第2および第3の端子のうちのいずれか1つの端子に接続する第1のスイッチと、
前記第1のスイッチの第2の端子に接続され、入力電流の極性を検出する第1の極性検出回路と、
前記第1の光センサの出力ノードおよび前記第1のスイッチの第3の端子に接続され、入力電流を積分して電荷量を検出する電荷量検出回路と、
前記第1の極性検出回路の検出結果に基づいて前記第1の制御信号を出力するとともに、前記電荷量検出回路の検出結果に基づいて前記第1および第2の光センサの設置場所の照度を示すデジタル信号を出力する演算制御部とを備える、照度センサ。 - さらに、前記第1および第2の光センサの各々と受光面積が異なり、光強度に応じた電流を出力する第3の光センサと、
前記第3の光センサの出力電流を受ける第1の端子と、第2および第3の端子とを有し、第2の制御信号に基づいて第1の端子を第2および第3の端子のうちのいずれか1つの端子に接続する第2のスイッチと、
前記第2のスイッチの第2の端子に接続され、入力電流の極性を検出する第2の極性検出回路とを備え、
前記電荷量検出回路は、さらに、前記第3の光センサの出力ノードおよび前記第2のスイッチの第3の端子に接続され、
前記演算制御部は、さらに、前記第2の極性検出回路の検出結果に基づいて前記第2の制御信号を出力するとともに、前記電荷量検出回路の検出結果に基づいて前記第1、第2および第3の光センサの設置場所の照度を示すデジタル信号を出力する、請求の範囲第1項に記載の照度センサ。 - 前記第1、第2および第3の光センサの各々は、
可視光領域で光感度が最大になる第1の光ダイオードと、
赤外光領域で光感度が最大になる第2の光ダイオードとを含み、
前記第1および第2の光ダイオードで発生した光電流の差の電流を出力する、請求の範囲第2項に記載の照度センサ。 - 前記第1の光ダイオードのカソードが第1の電源電圧を受け、前記第1の光ダイオードのアノードが出力ノードに接続され、
前記第2の光ダイオードのカソードが前記出力ノードに接続され、前記第2の光ダイオードのアノードが前記第1の電源電圧よりも低い第2の電源電圧を受ける、請求の範囲第3項に記載の照度センサ。 - 前記電荷量検出回路は、
第1のキャパシタと、
予め定められた充電期間だけ入力電流によって前記第1のキャパシタを充電させる第1の充電回路と、
前記第1のキャパシタの電荷量が予め定められた電荷量に到達する毎に前記第1のキャパシタを放電させる第1の放電回路と、
前記第1の充電回路による前記第1のキャパシタの充電が終了したことに応じて前記第1のキャパシタから一定の電流を流出させる第2の放電回路とを含み、
前記演算制御部は、前記第1の放電回路によって前記第1のキャパシタが放電された回数と前記第2の放電回路によって前記第1のキャパシタの全電荷を流出させるのに掛かった時間とに基づいて前記第1および第2の光センサの設置場所の照度を求める、請求の範囲第1項に記載の照度センサ。 - 前記第1の極性検出回路は、
前記第1のキャパシタよりも小さな電荷蓄積能力を有する第2のキャパシタと、
前記第1の光センサの出力電流によって前記第2のキャパシタを充電する第2の充電回路とを含み、
前記第2の充電回路は、前記第2のキャパシタの電荷量に応じたレベルの電圧を出力する演算増幅器を有し、
前記第1の極性検出回路は、さらに、前記演算増幅器の出力電圧が参照電圧に到達したことに応じて、対応の光センサの出力電流の極性が正であることを示す信号を出力する比較回路を含み、
前記第2の充電回路は、前記比較回路の出力信号に応答して前記第2のキャパシタの充電を停止する、請求の範囲第5項に記載の照度センサ。 - 前記第1の充電回路は、前記第1のキャパシタの電荷量に応じたレベルの電圧を出力する演算増幅器を含み、
前記第1の放電回路は、
前記第1のキャパシタと同じ電荷蓄積能力を有する第2のキャパシタと、
前記演算増幅器の出力電圧が第1の参照電圧に到達したことに応じて前記第1のキャパシタの電荷を前記第2のキャパシタに転送させる第1の転送回路とを含み、
前記第2の放電回路は、
前記第1のキャパシタよりも小さな電荷蓄積能力を有する第3のキャパシタと、
所定の周期で前記第1のキャパシタの電荷を前記第3のキャパシタに転送させ、前記演算増幅器の出力電圧が第2の参照電圧に到達したことに応じて電荷の転送を停止する第2の転送回路とを含む、請求の範囲第5項に記載の照度センサ。 - 前記演算制御部は、
前記電荷量検出回路の前記第1の充電回路、前記第1の放電回路、および前記第2の放電回路の各々を制御し、
前記予め定められた充電期間を複数の期間に分割し、最後の期間以外の各期間が終了する毎に前記第1の放電回路によって前記第1のキャパシタが放電された回数に基づいて前記照度のモニタ値を求め、求めたモニタ値が当該期間に対して予め定められた値を越えているか否かを判別し、
前記モニタ値が前記予め定められた値を越えている場合は前記第1のキャパシタの充電を終了し、前記第2の放電回路によって前記第1のキャパシタから1定の電流を流出させ、前記第1のキャパシタの充電時間と、前記第1のキャパシタの放電回数と、前記第2の放電回路によって前記第1のキャパシタの全電荷を流出させるのに掛かった時間とに基づいて前記照度を求め、
前記モニタ値が前記予め定められた値を越えていない場合は前記第1のキャパシタの充電を継続する、請求の範囲第5項に記載の照度センサ。 - 前記電荷量検出回路は、
第1の容量値を有する第1のキャパシタと、
前記第1の容量値よりも大きな第2の容量値を有する第2のキャパシタと、
予め定められた充電期間だけ入力電流によって前記第1のキャパシタを充電させる第1の充電回路と、
前記充電期間だけ前記第2のキャパシタを前記第1のキャパシタと同じ電圧に充電させる第2の充電回路と、
前記充電期間は、前記第1のキャパシタの電荷量が予め定められた電荷量に到達する毎に前記第1のキャパシタを放電させ、前記充電期間の終了後は、前記第1および第2のキャパシタから一定の電流を流出させる放電回路とを含み、
前記演算制御部は、前記充電期間内に前記第1のキャパシタが放電された回数と前記充電期間の終了後に前記第1および第2のキャパシタの全電荷を流出させるのに掛かった時間とに基づいて前記第1および第2の光センサの設置場所の照度を求める、請求の範囲第1項に記載の照度センサ。 - 前記第1の充電回路は、
一方端子が前記入力電流を受け、他方端子が前記第1のキャパシタの一方端子に接続され、前記充電期間だけ導通する第2のスイッチと、
反転入力端子が前記第1のキャパシタの一方端子に接続され、出力端子が前記第1のキャパシタの他方端子および前記第2のキャパシタの一方端子に接続され、非反転入力端子が第1の参照電圧を受ける演算増幅器とを含み、
前記第2の充電回路は、一方端子が前記第1の参照電圧を受け、他方端子が前記第2のキャパシタの他方端子に接続され、前記充電期間だけ導通する第3のスイッチと、
前記第2のキャパシタの他方端子と前記第1のキャパシタの一方端子との間に接続され、前記充電期間の終了後に導通する第4のスイッチとを含む、請求の範囲第9項に記載の照度センサ。 - 前記放電回路は、
前記第2の容量値よりも小さな第3の容量値を有する第3のキャパシタと、
前記演算増幅器の反転入力端子と第2の参照電圧のノードとの間に前記第3のキャパシタと直列接続された第5のスイッチと、
前記第3のキャパシタの端子間に接続された第6のスイッチとを含み、
前記第5および第6のスイッチのうちの一方が導通する場合は他方が非導通になり、
前記充電期間は、前記第1のキャパシタの電荷量が前記予め定められた電荷量に到達する毎に、前記第5のスイッチが導通して前記第1のキャパシタの全電荷が前記第3のキャパシタに1度に転送され、
前記充電期間の終了後は、前記第1および第2のキャパシタの電荷が無くなるまで、1定周期で前記第5のスイッチが導通して前記第1および第2のキャパシタの電荷が前記第3のキャパシタに転送され、
前記演算制御部は、前記充電期間内に前記第1のキャパシタが放電された回数と前記充電期間の終了後に前記第1および第2のキャパシタの電荷が前記第3のキャパシタに転送された回数とに基づいて前記第1および第2の光センサの設置場所の照度を求める、請求の範囲第10項に記載の照度センサ。 - 前記電荷量検出回路は、
入力電流に応じた電荷を蓄える第1の充電回路と、
前記第1の充電回路が蓄えている電荷に応じた電荷を蓄える第2の充電回路と、
一方端子が前記第1の充電回路の出力端子に接続され、他方端子が前記第2の充電回路の出力端子に接続された第2のスイッチとを含む、請求の範囲第1項に記載の照度センサ。 - 前記電荷量検出回路は、さらに、前記第1の充電回路に蓄えられた電荷を放電させる放電部を含む、請求の範囲第12項に記載の照度センサ。
- 前記第1の充電回路は、
出力端子が前記第2のスイッチの一方端子に接続され、非反転入力端子が第1の参照電圧を受ける第1の演算増幅器と、
前記第1の演算増幅器の反転入力端子および出力端子間に接続された第1の充電用キャパシタと、
前記入力電流を受ける前記第1の充電回路の入力端子と前記第1の演算増幅器の反転入力端子との間を開閉する第3のスイッチと、
前記第1の充電用キャパシタの端子間を開閉する第4のスイッチとを含む、請求の範囲第13項に記載の照度センサ。 - 前記第2の充電回路は、
一方端子が前記第1の演算増幅器の反転入力端子に接続される第5のスイッチと、
前記第5のスイッチの他方端子と前記第1のスイッチの他方端子との間に接続された第2の充電用キャパシタと、
出力端子が反転入力端子に接続され、非反転入力端子が第2の参照電圧を受ける第2の演算増幅器と、
前記第2のスイッチの他方端子と前記第2の演算増幅器の出力端子との間を開閉する第6のスイッチと、
前記第5のスイッチの他方端子と前記第2の演算増幅器の出力端子との間を開閉する第7のスイッチとを含む、請求の範囲第14項に記載の照度センサ。 - 前記放電部は第1および第2の放電回路を含み、
前記第1の放電回路は、
前記第1の充電用キャパシタの容量値の1/m(ただし、m≧1である)の容量値を有する第1の放電用キャパシタと、
前記第1の放電用キャパシタの一方端子と接地電圧のノードとの間を開閉するとともに、前記第1の放電用キャパシタの他方端子と前記第1の演算増幅器の反転入力端子との間を開閉する第8のスイッチと、
前記第1の放電用キャパシタの一方端子および他方端子の各々と前記第1の参照電圧のノードとの間を開閉する第9のスイッチとを有し、
前記第2の放電回路は、
前記第1の充電用キャパシタの1/n(ただし、n>mである)の容量を有する第2の放電用キャパシタと、
前記第2の放電用キャパシタの一方端子と前記第1の演算増幅器の反転入力端子との間を開閉するとともに、前記第2の放電用キャパシタの他方端子と前記第1の参照電圧の1/k(ただし、k>1である)の電圧値を有する第3の参照電圧のノードとの間を開閉する第10のスイッチと、
前記第2の放電用キャパシタの一方端子および他方端子の各々と前記第1の参照電圧のノードとの間を開閉する第11のスイッチとを有する、請求の範囲第15項に記載の照度センサ。 - 前記電荷量検出回路は、
さらに、非反転入力端子が前記第1の演算増幅器の出力端子に接続され、反転入力端子が第4の参照電圧を受ける第1のコンパレータと、
非反転入力端子が前記第1の演算増幅器の出力端子に接続され、反転入力端子が第5の参照電圧を受ける第2のコンパレータとを含み、
前記演算制御部は、前記第1および第2のコンパレータの出力信号に基づいて前記デジタル信号を出力する、請求の範囲第16項に記載の照度センサ。 - 前記第1の充電用キャパシタの容量値と前記第2の充電用キャパシタの容量値が等しく、前記第1の充電用キャパシタに蓄えられている電荷と等しい量の電荷を前記第2の充電用キャパシタに蓄える、請求の範囲第15項に記載の照度センサ。
- 前記電荷量検出回路は、並列接続された複数の前記第2の充電回路を含み、
複数の前記第2の充電回路の複数の前記第2の充電用キャパシタの容量値の和が前記第1の充電用キャパシタの容量値に等しい、請求の範囲第15項に記載の照度センサ。 - 前記電荷量検出回路が入力電流を積分する動作は、一時的に中断した後に再開することが可能になっている、請求の範囲第15項に記載の照度センサ。
- 請求の範囲第5項に記載の照度センサと、
画像を表示する液晶パネルと、
前記液晶パネルに透過光を与えるバックライトと、
前記照度センサの検出結果に基づいて前記バックライトの明るさを制御する制御装置とを備えた、電子機器。 - 請求の範囲第13項に記載の照度センサと、
赤外線反射型の近接センサと、
前記照度センサおよび前記近接センサを搭載した1枚の半導体基板とを備える、半導体装置。
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2012079975A (ja) * | 2010-10-04 | 2012-04-19 | Sony Corp | 受光素子、半導体装置、電子機器、および受光素子の製造方法、並びに半導体装置の製造方法 |
JP2013105963A (ja) * | 2011-11-15 | 2013-05-30 | Rohm Co Ltd | 光検出装置 |
KR20150015380A (ko) * | 2013-07-31 | 2015-02-10 | 미쓰미덴기가부시기가이샤 | 광센서용 반도체 집적회로 |
WO2023153112A1 (ja) * | 2022-02-08 | 2023-08-17 | ローム株式会社 | 検出回路、光学センサ |
JP7445436B2 (ja) | 2020-01-10 | 2024-03-07 | ローム株式会社 | 光学センサ |
Families Citing this family (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5323903B2 (ja) * | 2011-08-31 | 2013-10-23 | シャープ株式会社 | センサ回路および電子機器 |
JP2013197243A (ja) * | 2012-03-19 | 2013-09-30 | Rohm Co Ltd | 光センサ及びその出力回路 |
CN102937479A (zh) * | 2012-11-15 | 2013-02-20 | 北京昆腾微电子有限公司 | 光强检测电路和方法 |
CN103024495A (zh) * | 2012-12-04 | 2013-04-03 | 深圳市比维视创科技有限公司 | 光线感应遥控装置及其遥控方法 |
KR101552687B1 (ko) * | 2013-04-10 | 2015-09-15 | 주식회사 우리로 | 광 수신 장치 |
CN104244502B (zh) * | 2013-06-17 | 2017-07-07 | 株式会社理光 | 确定照度传感器的布置的方法、装置和照明控制系统 |
JP6184776B2 (ja) * | 2013-07-04 | 2017-08-23 | ローム株式会社 | 可視光通信システム |
DE102013014810B4 (de) * | 2013-09-05 | 2019-03-14 | Elmos Semiconductor Aktiengesellschaft | Vorrichtung zum Betreiben passiver Infrarotsensoren |
JP6207321B2 (ja) * | 2013-09-26 | 2017-10-04 | ローム株式会社 | 光センサ装置 |
KR101694729B1 (ko) * | 2014-01-20 | 2017-01-10 | 한국전자통신연구원 | 조명 스위치 장치 및 조명 스위칭 방법 |
US9752929B2 (en) * | 2014-05-08 | 2017-09-05 | Pinnacle Imaging Corporation | Light-detecting device and method for converting optical radiation on switched conductivity diodes |
JP6607709B2 (ja) * | 2015-06-08 | 2019-11-20 | ローム株式会社 | 近接センサ |
JP6499031B2 (ja) * | 2015-06-30 | 2019-04-10 | エイブリック株式会社 | 電子機器 |
DE102016207355A1 (de) * | 2016-04-29 | 2017-11-02 | Ford Global Technologies, Llc | LED-Anordnung und Verfahren zur umgebungslichtabhängigen Helligkeitssteuerung von LEDs |
FR3058263B1 (fr) | 2016-11-03 | 2019-08-23 | Lynred | Dispositif de detection multispectrale ameliore. |
US20180146149A1 (en) | 2016-11-21 | 2018-05-24 | Samsung Electronics Co., Ltd. | Event-based sensor, user device including the same, and operation method of the same |
CN109870233B (zh) * | 2017-12-05 | 2020-11-03 | 上海耕岩智能科技有限公司 | 光侦测薄膜、光侦测器件、光侦测装置 |
TWI815244B (zh) * | 2020-12-14 | 2023-09-11 | 瑞士商艾姆微體電子 馬林公司 | 指向裝置之位移的感測裝置 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0572029A (ja) * | 1991-09-11 | 1993-03-23 | Nec Corp | 光パワーメータ |
JP2003214950A (ja) * | 2002-01-22 | 2003-07-30 | Canon Inc | 光電変換装置及び撮像装置 |
JP2006118965A (ja) * | 2004-10-21 | 2006-05-11 | Seiko Epson Corp | 光検出回路、電気光学装置、および電子機器 |
JP2008042886A (ja) * | 2006-07-14 | 2008-02-21 | Rohm Co Ltd | アナログ/ディジタル変換器、照度センサ、照明装置、電子機器 |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR920009206B1 (ko) * | 1990-01-25 | 1992-10-14 | 삼성전자 주식회사 | 적분형 아날로그/디지탈 변환기의 기준전원 자동 제어회로 |
US6002355A (en) * | 1997-06-26 | 1999-12-14 | Cirrus Logic, Inc. | Synchronously pumped substrate analog-to-digital converter (ADC) system and methods |
JP2006118865A (ja) * | 2004-10-19 | 2006-05-11 | Toshiba Corp | 原子炉構造物の溶接部強度予測方法ならびにそのシステムおよびプログラム |
KR20070085114A (ko) * | 2004-11-05 | 2007-08-27 | 마츠시타 덴끼 산교 가부시키가이샤 | 영상 신호 변환 장치 및 영상 표시 장치 |
CN1719206A (zh) * | 2005-08-04 | 2006-01-11 | 上海大学 | 液滴的光敏计量方法及装置 |
JP2008041884A (ja) * | 2006-08-04 | 2008-02-21 | Rohm Co Ltd | 半導体集積回路およびそれを備えた電子機器 |
JP2009004483A (ja) * | 2007-06-20 | 2009-01-08 | Sharp Corp | 発光ダイオード駆動回路 |
JP5301240B2 (ja) | 2007-12-05 | 2013-09-25 | 株式会社ジャパンディスプレイウェスト | 表示装置 |
-
2010
- 2010-03-23 JP JP2011506052A patent/JP5635975B2/ja active Active
- 2010-03-23 CN CN201080003100.XA patent/CN102203572B/zh active Active
- 2010-03-23 US US13/125,457 patent/US8513892B2/en active Active
- 2010-03-23 WO PCT/JP2010/054945 patent/WO2010110249A1/ja active Application Filing
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0572029A (ja) * | 1991-09-11 | 1993-03-23 | Nec Corp | 光パワーメータ |
JP2003214950A (ja) * | 2002-01-22 | 2003-07-30 | Canon Inc | 光電変換装置及び撮像装置 |
JP2006118965A (ja) * | 2004-10-21 | 2006-05-11 | Seiko Epson Corp | 光検出回路、電気光学装置、および電子機器 |
JP2008042886A (ja) * | 2006-07-14 | 2008-02-21 | Rohm Co Ltd | アナログ/ディジタル変換器、照度センサ、照明装置、電子機器 |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2012079975A (ja) * | 2010-10-04 | 2012-04-19 | Sony Corp | 受光素子、半導体装置、電子機器、および受光素子の製造方法、並びに半導体装置の製造方法 |
JP2013105963A (ja) * | 2011-11-15 | 2013-05-30 | Rohm Co Ltd | 光検出装置 |
KR20150015380A (ko) * | 2013-07-31 | 2015-02-10 | 미쓰미덴기가부시기가이샤 | 광센서용 반도체 집적회로 |
JP2015028455A (ja) * | 2013-07-31 | 2015-02-12 | ミツミ電機株式会社 | 光センサ用半導体集積回路 |
KR102137241B1 (ko) * | 2013-07-31 | 2020-07-24 | 미쓰미덴기가부시기가이샤 | 광센서용 반도체 집적회로 |
JP7445436B2 (ja) | 2020-01-10 | 2024-03-07 | ローム株式会社 | 光学センサ |
WO2023153112A1 (ja) * | 2022-02-08 | 2023-08-17 | ローム株式会社 | 検出回路、光学センサ |
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