JP6716902B2 - Electronics - Google Patents

Description

The present invention relates to electronic devices.

A time-of-flight (TOF) measuring method is known in which the distance to an object is measured by receiving the reflected light of the light applied to the object (for example, Patent Document 1). It is known that the TOF measurement method has a problem that the accuracy of distance measurement decreases depending on the environment.

Patent No. 5395323

The electronic device according to the first aspect includes a first photoelectric conversion unit that photoelectrically converts light from a subject that has passed through the first pupil region of the optical system to generate electric charges, and the first photoelectric conversion unit. A first pixel having a first output section and a second output section that output a signal based on electric charge, and photoelectrically convert light from the subject that has passed through a second pupil area different from the first pupil area. a second photoelectric conversion unit that generates charges Te, and the imaging unit and a second pixel and a third output portion and a fourth output unit for outputting a signal based on the electric charge produced in the second photoelectric conversion unit A first distance measuring unit that measures a distance to the subject based on a signal output from the first output unit and a signal output from the third output unit; and an output from the first output unit. To the object based on at least one of the signal output from the third output unit and the signal output from the third output unit and the signal output from the second output unit. A second distance measuring unit for measuring
The electronic device according to the second aspect includes a first photoelectric conversion unit that photoelectrically converts light from a subject that has passed through the first pupil region of the optical system to generate electric charges, and the first photoelectric conversion unit. A first pixel having a first output section and a second output section that output a signal based on electric charge, and photoelectrically convert light from the subject that has passed through a second pupil area different from the first pupil area. a second photoelectric conversion unit that generates charges Te, and the imaging unit and a second pixel and a third output portion and a fourth output unit for outputting a signal based on the electric charge produced in the second photoelectric conversion unit A first distance measuring unit that measures a distance from the imaging unit to the subject based on a signal output from the first output unit and a signal output from the third output unit , and the first output Based on at least one of a signal output from a unit and a signal output from the second output unit, and a signal output from the third output unit and a signal output from the fourth output unit, A second distance measuring unit that measures the distance to the subject, and a control unit that can select one of the measurement by the first distance measuring unit and the measurement by the second distance measuring unit .

It is a sectional view showing typically composition of an imaging device concerning a 1st embodiment. 3 is a block diagram schematically showing the configuration of the image pickup unit 12. FIG. It is a top view which shows the structure of the horizontal block 21a typically. It is a figure which shows the circuit structure of the non-ranging pixel 301 and the 1st ranging pixel 302a. 3 is a diagram showing a circuit configuration of a receiving circuit 53 included in the control unit 13. FIG. It is a figure which shows the structure of the non-ranging pixel 301 typically. It is a figure which shows typically the structure of the pixel 302a for 1st ranging, and the pixel 302b for 2nd ranging. It is a top view which shows the structure of the vertical block 21b typically. 7 is a flowchart of a focus adjustment process executed by the control unit 13. 3 is a plan view schematically showing a part of the image pickup surface of the image pickup section 12. FIG. It is an enlarged view of the 1st pixel 303a. It is a figure which shows the modification of the receiving circuit 53.

(First embodiment)
FIG. 1 is a cross-sectional view schematically showing the configuration of the image pickup apparatus according to the first embodiment. The image pickup apparatus 1 includes a light source unit 10, an image pickup optical system 11, an image pickup unit 12, and a control unit 13.

The light source unit 10 emits the measurement light beam 3 to the DUT 2. The measurement light beam 3 is, for example, visible light. The measurement light beam 3 may be infrared light. Of the measurement light flux 3, the reflected light flux 4 reflected by the surface of the DUT 2 passes through the imaging optical system 11 and enters the imaging unit 12. The imaging unit 12 is, for example, a backside illumination type CMOS image sensor.

The control unit 13 includes a CPU (not shown) and its peripheral circuits. The control unit 13 controls the entire imaging device 1 by reading and executing a predetermined control program. The control unit 13 includes a first distance measuring unit 13a, a second distance measuring unit 13b, a photometric unit 13c, and a focus adjusting unit 13d. Each of these units included in the control unit 13 is realized as software by the above control program. Each of these units included in the control unit 13 may be configured by an electronic circuit or the like having an equivalent function.

The first distance measuring unit 13a and the second distance measuring unit 13b measure (distance measuring) the distance to the DUT 2 based on the photoelectric conversion signal output from the imaging unit 12. The first distance measuring unit 13a and the second distance measuring unit 13b perform distance measurement by different methods. The photometric unit 13c measures the object 2 to be measured based on the photoelectric conversion signal output from the imaging unit 12. Note that the image pickup device 1 may be provided with an optical sensor or the like different from the image pickup unit 12, and the photometric unit 13c may measure the object 2 to be measured based on the output of the optical sensor or the like. The focus adjustment unit 13d adjusts the focus of the imaging optical system 11.

FIG. 2 is a block diagram schematically showing the configuration of the image pickup unit 12. The image pickup surface 20 of the image pickup unit 12 is composed of a total of 24 blocks 21 each of which is horizontal 6×vertical 4. Five distance measuring areas 22 are provided on the imaging surface 20. Three of the five distance measuring areas 22 are horizontally long distance measuring areas 22a, and the remaining two are vertically long distance measuring areas 22b. The first distance measurement unit 13a and the second distance measurement unit 13b perform distance measurement for each of the five distance measurement areas 22.

Each of the 24 blocks 21 includes a part of one of the distance measurement areas 22. Sixteen of the 24 blocks 21 are horizontal blocks 21a including a part of the horizontally long distance measuring area 22a. The remaining eight are vertical blocks 21b including a part of the vertically long distance measuring area 22b.

The imaging unit 12 has a horizontal scanning circuit 23 and a vertical scanning circuit 24. For each block 21, the horizontal scanning circuit 23 and the vertical scanning circuit 24 scan the image pickup pixels included in the block 21 and read out photoelectric conversion signals.

FIG. 3 is a plan view schematically showing the configuration of the horizontal block 21a. A plurality of imaging pixels 30 are two-dimensionally arranged in the horizontal block 21a. The plurality of imaging pixels 30 include three types of pixels: a non-distance measuring pixel 301, a first distance measuring pixel 302a, and a second distance measuring pixel 302b. In the horizontally long distance measuring area 22a, the first distance measuring pixels 302a and the second distance measuring pixels 302b are arranged alternately in the horizontal direction (x direction). Non-ranging pixels 301 are arranged at other locations.

In the plurality of imaging pixels 30 arranged in the horizontal block 21a, when the photoelectric conversion signal is read, the first row is read at the same time, and then the second row and thereafter are sequentially read. Therefore, the photoelectric conversion signals read from the first distance measuring pixel 302a and the second distance measuring pixel 302b in the horizontally long distance measuring area 22a have simultaneity.

FIG. 4 is a diagram showing a circuit configuration of the non-ranging pixel 301 and the first ranging pixel 302a. The non-distance measuring pixel 301 has a photodiode PD, a transfer transistor TX, a reset transistor RST, a selection transistor SEL, and an amplification transistor AMP.

The photodiode PD photoelectrically converts incident light to generate signal charges. The generated signal charge is transferred to the floating diffusion FD via the transfer transistor TX. The amplification transistor AMP outputs a signal corresponding to the amount of signal charge accumulated in the floating diffusion FD to the selection transistor SEL. When the vertical scanning circuit 24 turns on the selection transistor SEL, a signal corresponding to the amount of signal charges accumulated in the floating diffusion FD is output to the control unit 13. The signal charge transferred to the floating diffusion FD is reset by turning on/off the reset transistor RST.

In the following description, for convenience, a portion including the transfer transistor TX, the selection transistor SEL, and the amplification transistor AMP is referred to as an output unit 50. The output unit 50 outputs the photoelectric conversion signal from the photodiode PD to the control unit 13. The control unit 13 has one receiving circuit 53 for each column. The receiving circuit 53 is a circuit that receives the photoelectric conversion signal output by the output unit 50. The configuration of the receiving circuit 53 will be described later in detail.

The first distance measuring pixel 302a includes a photodiode PDa, a first transfer transistor TX1, a first reset transistor RST1, a first selection transistor SEL1, a first amplification transistor AMP1, a second transfer transistor TX2, a second reset transistor RST2, and a second reset transistor RST2. The second selection transistor SEL2 and the second amplification transistor AMP2 are included.

The first transfer transistor TX1, the first reset transistor RST1, the first selection transistor SEL1, and the first amplification transistor AMP1 are respectively the transfer transistor TX, the reset transistor RST, the selection transistor SEL, and the amplification which the non-ranging pixel 301 has. Works like the transistor AMP. The same applies to the second transfer transistor TX2, the second reset transistor RST2, the second selection transistor SEL2, and the second amplification transistor AMP2.

That is, the first distance measuring pixel 302a has two sets of circuits corresponding to the output section 50 of the non-distance measuring pixel 301. In the following description, for convenience, a portion including the first transfer transistor TX1, the first selection transistor SEL1, and the first amplification transistor AMP1 is referred to as a first output unit 51, and the second transfer transistor TX2, the second selection transistor SEL2, and A portion including the second amplification transistor AMP2 is referred to as a second output unit 52. The first distance measuring pixel 302a is configured to be able to separately read the signal charges generated by the photodiode PDa from the first output section 51 and the second output section 52.

The control unit 13 has two receiving circuits 53 for each column for the column including the first distance measuring pixel 302a or the second distance measuring pixel 302b. One receiving circuit 53 is a circuit that receives the photoelectric conversion signal output by the first output unit 51. The other receiving circuit 53 is a circuit that receives the photoelectric conversion signal output by the second output unit 52.

The circuit configuration of the second distance measuring pixel 302b is the same as that of the first distance measuring pixel 302a, and thus the description thereof is omitted.

FIG. 5 is a diagram showing a circuit configuration of the receiving circuit 53 included in the control unit 13. The receiving circuit 53 removes a noise component from the received photoelectric conversion signal by correlated double sampling (CDS). The receiving circuit 53 converts the photoelectric conversion signal from which the noise component has been removed into a digital value. The receiving circuit 53 outputs a digital value obtained by converting the photoelectric conversion signal.

The receiving circuit 53 clamps the feedthrough period immediately after resetting the imaging pixel 30 with the switch 531 on the upper side of the drawing. The receiving circuit 53 clamps the output period of the photoelectric conversion signal with the switch 532 on the lower side of the drawing. After that, the receiving circuit 53 turns on the switch 533 and the switch 534, inputs the clamped voltage to the differential amplifier 535, and takes the difference between the two voltages. The receiving circuit 53 converts the output of the differential amplifier 535 into a 12-bit digital value by the AD converter 536 and outputs the digital value. As described above, the control unit 13 can read the digital value from which the amplifier noise and the reset noise have been removed as the pixel value.

6A is a cross-sectional view schematically showing the configuration of the non-distance measuring pixel 301, and FIG. 6B is a plan view schematically showing the configuration of the non-distance measuring pixel 301. The upper side of the paper surface of FIG. 6A is the incident surface of the light flux from the DUT 2. That is, the light flux from the DUT 2 is incident from the upper side of the paper surface of FIG. The lowermost layer of the imaging unit 12 is the wiring layer 40. On the upper layer of the wiring layer 40, a silicon substrate 41 and a microlens 43 are sequentially arranged.

A photodiode PD, a source/drain electrode 45, and a pixel separation structure 46 are formed on the silicon substrate 41. The pixel separation structure 46 is a structure that electrically separates the non-distance measuring pixels 31 from each other. The pixel isolation structure 46 is, for example, so-called STI (shallow trench isolation). The source/drain electrodes 45 are the source electrode and the drain electrode of the transfer transistor TX shown in FIG.

A gate electrode 47 and a wiring 48 are formed on the wiring layer 40. The gate electrode 47 is the gate electrode of the transfer transistor TX shown in FIG. The wiring 48 is a wiring that configures each circuit of the non-ranging pixel 301.

The light flux from the DUT 2 passes through the microlens 43 and enters the photodiode PD formed in the silicon substrate 41. The photodiode PD generates an amount of signal charge according to the amount of light of the incident light flux. As shown in FIG. 6B, the surface area of the photodiode PD is made as large as possible in order to improve the light collection efficiency. The photodiode PD configured as described above receives the light flux that has passed through the entire exit pupil of the imaging optical system 11.

FIG. 7A is a sectional view schematically showing the configuration of the first distance measuring pixel 302a and the second distance measuring pixel 302b, and FIG. 7B is a sectional view showing the first distance measuring pixel 302a and the first distance measuring pixel 302a. It is a top view which shows typically the structure of the 2nd distance measurement pixel 302b.

The first distance measuring pixel 302a has a microlens 43a and a photodiode PDa. As shown in FIG. 6B, the photodiode PDa is arranged biased to the right half of the microlens 43a. A light blocking member 42 is arranged between the microlens 43a and the silicon substrate 41. The light blocking member 42 is arranged so as to cover the left half of the microlens 43a.

The photodiode PDa configured as described above receives the light flux that has passed through a partial pupil region (pupil region corresponding to the right half of the microlens 43a) of the entire exit pupil of the imaging optical system 11. The light flux that has passed through the remaining area is blocked by the light blocking member 42 and does not reach the photodiode PDa.

A photodiode PDa, a source/drain electrode 45, and a pixel separation structure 46 are formed on the silicon substrate 41. The source/drain electrodes 45 are the source electrodes and drain electrodes of the transfer transistors TX1 and TX2 shown in FIG.

Gate electrodes 471 and 472 and a wiring 48 a are formed on the wiring layer 40. The gate electrode 471 is the gate electrode of the transfer transistor TX1 shown in FIG. The gate electrode 472 is the gate electrode of the transfer transistor TX2 shown in FIG. The wiring 48a is a wiring configuring each circuit of the first distance measuring pixel 302a.

The gate electrodes 471 and 472 and the wiring 48 a are both arranged under the light shielding member 42. Therefore, the light flux that has passed through the microlens 43a does not reach these portions. As a result, these parts are not affected by the photoelectric effect.

The second distance measuring pixel 302b has a microlens 43b and a photodiode PDb. As shown in FIG. 6B, the photodiode PDb is arranged biased to the left half of the microlens 43b. A light blocking member 42 is arranged between the microlens 43b and the silicon substrate 41. The light blocking member 42 is arranged so as to cover the right half of the microlens 43b.

The photodiode PDb configured as described above receives a light flux that has passed through a partial pupil region (a region corresponding to the left half of the microlens 43b) of the entire exit pupil of the imaging optical system 11. The light flux that has passed through the remaining area is blocked by the light blocking member 42 and does not reach the photodiode PDb.

A photodiode PDb, a source/drain electrode 45, and a pixel separation structure 46 are formed on the silicon substrate 41. The source/drain electrodes 45 are the source electrodes and drain electrodes of the transfer transistors TX1 and TX2 shown in FIG.

Gate electrodes 473 and 474 and a wiring 48b are formed on the wiring layer 40. The gate electrode 473 is the gate electrode of the transfer transistor TX1 shown in FIG. The gate electrode 474 is the gate electrode of the transfer transistor TX2 shown in FIG. The wiring 48b is a wiring forming each circuit of the second distance measuring pixel 302b.

The gate electrodes 473 and 474 and the wiring 48b are both arranged under the light shielding member 42. Therefore, the light flux that has passed through the microlens 43b does not reach these portions. As a result, these parts are not affected by the photoelectric effect.

FIG. 8 is a plan view schematically showing the configuration of the vertical block 21b. A plurality of imaging pixels 30 are two-dimensionally arranged in the vertical block 21b. The plurality of imaging pixels 30 include three types of pixels, a non-distance measuring pixel 301, a third distance measuring pixel 302c, and a fourth distance measuring pixel 302d. In the vertically long distance measuring area 22b, the third distance measuring pixels 302c and the fourth distance measuring pixels 302d are arranged alternately in the vertical direction (y direction). Non-ranging pixels 301 are arranged at other locations.

In the plurality of imaging pixels 30 arranged in the vertical block 21b, when the photoelectric conversion signal is read, first the first column is read simultaneously, and then the second and subsequent columns are sequentially read. Therefore, the photoelectric conversion signals read from the third distance measuring pixel 302c and the fourth distance measuring pixel 302d in the vertically long distance measuring area 22b have simultaneity.

The third distance measuring pixel 302c has a configuration in which the first distance measuring pixel 302a on the xy plane is rotated clockwise by 90 degrees. That is, the third distance measuring pixel 302c has a microlens and a photodiode. The photodiode is arranged in a biased manner in the lower half of the microlens. The third distance measuring pixel 302c has a light shielding member arranged so as to cover the upper half of the microlens. Therefore, the photodiode included in the third distance measuring pixel 302c is a partial pupil area (different from the first distance measuring pixel 302a and the second distance measuring pixel 302b) in the entire exit pupil of the imaging optical system 11. The light flux that has passed through the pupil area corresponding to the lower half of the microlens is received.

The fourth distance measuring pixel 302d has a configuration in which the second distance measuring pixel 302b on the xy plane is rotated clockwise by 90 degrees. That is, the fourth distance measuring pixel 302d has a microlens and a photodiode. The photodiode is arranged in the upper half of the microlens in a biased manner. The fourth distance measuring pixel 302d has a light shielding member arranged so as to cover the lower half of the microlens. Therefore, the photodiode included in the fourth distance measuring pixel 302d is the first distance measuring pixel 302a, the second distance measuring pixel 302b, the third distance measuring pixel 302c in the entire exit pupil of the imaging optical system 11. A light beam that has passed through a part of a different pupil region (a pupil region region corresponding to the upper half of the microlens) is received.

(Explanation of distance measurement of the phase difference detection method by the first distance measuring unit 13a)
The distance measuring operation by the first distance measuring unit 13a will be described. In the following description, one of the horizontally long distance measuring areas 22a will be described as an example. The vertically long distance measuring area 22b has the same operation except that the distance measuring direction and the reading direction are the vertical direction, and thus the description thereof will be omitted.

The first distance measuring unit 13a performs so-called phase difference detection type distance measurement. The first distance measuring unit 13a reads a photoelectric conversion signal via the first output unit 51 from each of the first distance measuring pixels 302a arranged laterally every other pixel. The plurality of photoelectric conversion signals read here are referred to as a signal sequence a(i). The first distance measuring unit 13a reads a photoelectric conversion signal via the first output unit 51 from each of the second distance measuring pixels 302b arranged laterally every other pixel. The plurality of photoelectric conversion signals read here are referred to as a signal sequence b(i). The exposure timing and the read timing for generating the signal train a(i) and the signal train b(i) are the same.

The first distance measuring unit 13a performs a correlation calculation based on the signal sequence a(i) and the signal sequence b(i), and detects a shift (phase difference) between the signal sequence a(i) and the signal sequence b(i). .. Then, the deviation (phase difference) is multiplied by a predetermined coefficient to calculate the distance to the DUT 2.

The signal sequence a(i) may be read using the second output section 52. Similarly, the signal sequence b(i) may be read using the second output unit 52.

The first distance measuring unit 13a can also read the photoelectric conversion signal from the third distance measuring pixel 302c and the fourth distance measuring pixel 302d in the same manner to calculate the distance to the DUT 2. Since the first distance measurement pixels 302a and the second distance measurement pixels 302b are arranged in the horizontal direction, distance measurement is performed based on the lateral displacement (phase difference) of the DUT 2. On the other hand, since the third distance-measuring pixels 302c and the fourth distance-measuring pixels 302d are arranged in the vertical direction, distance measurement is performed based on the vertical displacement (phase difference) of the DUT 2.

(Explanation of TOF measurement distance measurement by the second distance measurement unit 13b)
The distance measuring operation by the second distance measuring unit 13b will be described. In the following description, one of the horizontally long distance measuring areas 22a will be described as an example. The vertically long distance measuring area 22b has the same operation except that the distance measuring direction is the vertical direction, and thus description thereof will be omitted.

The second distance measuring unit 13b performs distance measurement using a so-called TOF measurement method. When the distance is measured by the second distance measuring unit 13b, the light source unit 10 emits the measurement light beam 3 to the object to be measured 2. The measurement light beam 3 is pulsed light having a predetermined width. That is, the light source unit 10 emits light having a constant intensity for a predetermined period.

The measurement light flux 3 emitted from the light source unit enters the first distance measuring pixel 302a as the reflected light flux 4. The second distance measuring unit 13b reads out the photoelectric conversion signal via the first output unit 51 of the first distance measuring pixel 302a at a predetermined time. The second distance measuring unit 13b then reads out the photoelectric conversion signal via the second output unit 52 of the first distance measuring pixel 302a. In other words, the second distance measuring unit 13b divides the photoelectric conversion signal for a fixed period by the first distance measuring pixel 302a into periods before and after a predetermined time as a boundary and reads them separately.

The second distance measuring unit 13b, for the same first distance measuring pixel 302a, the signal amount of the photoelectric conversion signal read from the first output unit 51 and the photoelectric conversion signal read from the second output unit 52. The ratio with the signal amount of is calculated. The second distance measuring unit 13b calculates the delay time of the reflected light flux 4 from the calculated ratio. The delay time of the reflected light beam 4 is the time from when the measurement light beam 3 leaves the light source unit 10 to when it is reflected by the surface of the DUT 2 and becomes the reflected light beam 4 and reaches the imaging unit 12. The second distance measuring unit 13b calculates the distance to the DUT 2 from the delay time and the known speed of light.

The second distance measuring unit 13b can also perform distance measurement of the DUT 2 in the same manner for the second distance measuring pixel 302b, the third distance measuring pixel 302c, and the fourth distance measuring pixel 302d. .. The specific procedure of distance measurement is the same as that of the above-described first distance measurement pixel 302a, and thus the description thereof is omitted.

(Explanation of focus adjustment processing)
FIG. 9 is a flowchart of the focus adjustment process executed by the control unit 13. In step S100, the photometric unit 13c measures the object 2 to be measured. In step S110, the focus adjustment unit 13d determines whether or not the light amount that is the photometric result of the DUT 2 exceeds a predetermined threshold value. When the light amount exceeds the predetermined threshold value, that is, when the light amount is large, the focus adjustment unit 13d advances the process to step S120.

In step S120, the first distance measuring unit 13a outputs photoelectric conversion signals from the first output units 51 of the first distance measuring pixels 302a and the second distance measuring pixels 302b arranged in the five distance measuring areas 22. read out. By this reading, five signal trains a(i) and signal trains b(i) corresponding to each of the five distance measuring areas 22 are created. In step S130, the first distance measuring unit 13a detects the deviation (phase difference) of each of the five signal sequences a(i) and b(i). In step S140, the first distance measuring unit 13a calculates the distance of the DUT 2 corresponding to each of the five distance measuring areas 22 from the shift (phase difference) corresponding to each of the five distance measuring areas 22. ..

When the light amount does not exceed the predetermined threshold value in step S110, the focus adjustment unit 13d advances the process to step S150. In step S150, the second distance measuring unit 13b causes the light source unit 10 to emit the measurement light flux 3. In step S160, the second distance measuring unit 13b outputs photoelectric conversion signals from the first output units 51 of the first distance measuring pixels 302a and the second distance measuring pixels 302b arranged in the five distance measuring areas 22. read out. In step S170, the second distance measuring unit 13b outputs photoelectric conversion signals from the second output units 52 of the first distance measuring pixels 302a and the second distance measuring pixels 302b arranged in the five distance measuring areas 22. read out.

In step S180, the second distance measuring unit 13b calculates the signal amount of the photoelectric conversion signal read from the first output unit 51 and the photoelectric conversion signal read from the second output unit 52 for each of the five distance measuring regions 22. The delay time of the measurement light beam 3 is calculated based on the ratio with the signal amount. In step S190, the second distance measuring unit 13b calculates the distance of the DUT 2 corresponding to each of the five distance measuring areas 22 based on the delay time corresponding to each of the five distance measuring areas 22.

In step S200, the focus adjustment unit 13d adjusts the focus of the imaging optical system 11 based on the distance of the DUT 2 calculated in step S140 or the distance of the DUT 2 calculated in step S190. Since the distance to the DUT 2 is calculated for each of the five distance measuring areas 22, the focus adjusting unit 13d selects, for example, one distance measuring area 22 to be the target of focus adjustment, or five distance measuring areas 22. Focus adjustment is performed by determining the final target distance from the distances calculated for each of the distance regions 22.

According to the image pickup apparatus according to the first embodiment described above, the following operational effects can be obtained.
(1) The photodiode PDa of the first distance measuring pixel 302a receives the light flux that has passed through the first pupil area, which is a partial area of the exit pupil of the imaging optical system 11, and outputs the first signal. The photodiode PDb of the second distance measuring pixel 302b receives the light flux that has passed through the second pupil area, which is another partial area of the exit pupil of the imaging optical system 11, and outputs a second signal. The first distance measuring unit 13a measures the distance to the DUT 2 based on the shift (phase difference) between the first signal and the second signal. The second distance measuring unit 13b, based on the first signal output by the photodiode PDa that receives the light flux of the measurement light flux 3 emitted by the light source unit 10 that is reflected by the DUT 2 and has passed through the first pupil region, The delay time from the emission of the measurement light beam 3 to the reception of light is detected to measure the distance to the object to be measured. Since this is done, distance measurement based on the TOF measurement method and distance measurement based on the phase difference detection method can be used together. In particular, since the image pickup unit 12 can be a single image pickup device, it is possible to obtain flexibility in which two types of distance measurement can be used together without increasing the number of components.

(2) The imaging unit 12 outputs the first signal based on the luminous flux received by the photodiode PDa from the first time to the second time, and the second output from the second time to the third time. A second output unit 52 that outputs a first signal based on the light beam received by the photodiode PDa is provided therebetween. The second distance measuring unit 13b detects a delay time from emission to reception of the measurement light beam 3 based on the first signal output from the first output unit 51 and the first signal output from the second output unit 52. To do. Since this is done, distance measurement based on the TOF measurement method can be performed in a situation where the phase difference detection method is not suitable, and flexible distance measurement can be performed according to the situation.

(3) The second distance measuring unit 13b uses the first signal based on the light flux received between the first time and the second time and the first signal based on the light flux received between the second time and the third time. The delay time from the emission of the measurement light beam 3 to the light reception is detected based on the difference in the signal amount from the signal. Since this is done, distance measurement based on the TOF measurement method can be performed in a situation where the phase difference detection method is not suitable, and flexible distance measurement can be performed according to the situation.

(4) The focus adjusting unit 13d adjusts the focus of the imaging optical system 11 based on the measurement result of the first distance measuring unit 13a when the light amount measured by the light measuring unit 13c is equal to or more than the predetermined amount, and the light measuring unit 13c. If the amount of light measured by is less than the predetermined amount, the focus of the imaging optical system 11 is adjusted based on the measurement result by the second distance measuring unit 13b. Since it did in this way, reliable focus adjustment can be performed irrespective of the light quantity of ambient light.

(5) The imaging unit 12 includes the first distance measuring pixel 302a including the microlens 43 and the photodiode PDa, and the second distance measuring pixel 302b including the microlens 43 and the photodiode PDb, which is different from the second distance measuring pixel 302b. Distance pixels 302b are included. Since it did in this way, the 1st ranging part 13a can perform the so-called phase difference type ranging.

(6) The first distance-measuring pixel 302a has the light shielding member 42 that shields the light flux that has passed through the region different from the first region of the exit pupil, and the second distance-measuring pixel 302b is the second region of the exit pupil. A light blocking member 42 that blocks a light beam that has passed through a region different from the region is provided. As a result, the photodiode PDa is prevented from receiving the light flux that has passed through the regions other than the first region, and the photodiode PDb is prevented from receiving the light flux that has passed through the regions other than the second region.

(7) Part of the first output section 51 and the second output section 52 is arranged in a range of the first distance measuring pixel 302a that is shielded by the light shielding member 42. Since it did in this way, the 1st output part 51 and the 2nd output part 52 are not affected by the photoelectric effect. Further, the space occupied by the first distance measuring pixel 302a can be effectively used.

(8) The imaging unit 12 receives the light flux that has passed through the third area, which is a partial area of the exit pupil different from both the first area and the second area, and outputs a third signal to the third measurement unit. A fourth distance measuring device having a distance pixel 302c and a photodiode that receives a light beam that has passed through a fourth region that is a partial region of an exit pupil different from any of the first to third regions and outputs a fourth signal. And a pixel 302d for use. The direction in which the photodiode PDa and the photodiode PDb are arranged side by side is different from the direction in which the photodiode of the third distance measuring pixel 302c and the photodiode of the fourth distance measuring pixel 302d are arranged side by side. Since this is done, distance measurement of the DUT 2 can be performed in different directions.

(9) The first distance measuring unit 13a performs distance measurement based on the phase difference detection method. Since the distance measurement based on the phase difference detection method can be performed without emitting the measurement light beam 3 from the light source unit 10, the power consumed by the emission of the measurement light beam 3 by the light source unit 10 can be saved.

(10) The second distance measuring unit 13b performs distance measurement based on the TOF measurement method. Since the distance measurement based on the TOF measurement method is performed using the measurement light flux 3 emitted from the light source unit 10, the distance measurement can be performed accurately even in a dark environment.

(Second embodiment)
In the above-described first embodiment, the distance measurement by the second distance measurement unit 13b is performed only in the area where the distance measurement pixels 302 are arranged. The image pickup apparatus according to the second embodiment has an image pickup unit 12 capable of performing distance measurement by the first distance measurement unit 13a and the second distance measurement unit 13b in all areas on the image pickup surface. In the following description, the same parts as those in the first embodiment will be designated by the same reference numerals and the description thereof will be omitted.

FIG. 10 is a plan view schematically showing a part of the image pickup surface of the image pickup unit 12. The pixels 303 are two-dimensionally arranged on the imaging surface of the imaging unit 12. The pixel 303 includes four types of first pixel 303a, second pixel 303b, third pixel 303c, and fourth pixel 303d.

The pixel 303 has a square shape. The pixels 303 are two-dimensionally arranged on the xy plane in a state where the square is rotated by 45 degrees. In the column 121, the first pixels 303a and the second pixels 303b are arranged alternately (every other pixel). In the column 122 adjacent to the column 121, the third pixel 303c and the fourth pixel 303d are arranged alternately (every other pixel).

FIG. 11 is an enlarged view of the first pixel 303a. The first pixel 303a includes the microlens 43 having a square shape and the photodiode PD having a right triangle shape. The photodiode PD is arranged so as to occupy the left half region of the first pixel 303a. The gate electrode 47 of the transfer transistor and the wiring 48 are arranged on the remaining right half of the first pixel 303a. The light blocking member 42 that covers the gate electrode 47 and the wiring 48 is disposed on the right half of the first pixel 303a. Due to the light shielding member 42, the reflected light flux 4 does not enter the gate electrode 47 and the wiring 48.

The circuit configuration of the first pixel 303a is the same as that of the non-distance measuring pixel 301 shown in FIG. That is, the first pixel 303a does not have the two output units 51 and 52 like the distance measuring pixel 302, but has only the single output unit 50.

The second pixel 303b is a pixel obtained by rotating the first pixel 303a 180 degrees clockwise. Similarly, the third pixel 303c is a pixel obtained by rotating the first pixel 303a clockwise by 90 degrees, and the fourth pixel 303d is a pixel obtained by rotating the first pixel 303a clockwise by 270 degrees.

The distance measuring operation by the first distance measuring unit 13a will be described. The first distance measuring unit 13a of the present embodiment can perform distance measurement in the vertical direction, the horizontal direction, and the diagonal direction at any position on the imaging surface. For example, by creating the signal sequence a(i) and the signal sequence b(i) described in the first embodiment from the first pixel 303a and the second pixel 303b arranged in the horizontal direction, Distance measurement can be performed. Similarly, by forming the signal sequence a(i) and the signal sequence b(i) from the third pixel 303c and the fourth pixel 303d arranged in the vertical direction, distance measurement in the vertical direction can be performed. .. The same applies to the diagonal direction.

The distance measuring operation by the second distance measuring unit 13b will be described. The second distance measuring unit 13b of the present embodiment can perform distance measurement using the TOF measurement method at any position on the imaging surface. The second distance measuring unit 13b considers that the reflected light flux 4 from the same position of the DUT 2 is incident on the two adjacent pixels 303, and performs the distance measurement by the TOF measurement method. Here, "two adjacent pixels 303" refers to two pixels 303 that are adjacent in the vertical direction, the horizontal direction, or the diagonal direction.

The second distance measuring unit 13b reads the photoelectric conversion signal from one of the two adjacent pixels 303 via the output unit 50 at a predetermined time. The second distance measuring unit 13b then reads the photoelectric conversion signal from the other of the two adjacent pixels 303 via the output unit 50. Assuming that the reflected light flux 4 from the same position of the DUT 2 enters these two pixels 303, the photoelectric conversion signal based on the reflected light flux 4 from the same position is divided into a period before and after a predetermined time as a boundary. It means that they are read separately.

According to the imaging device of the second embodiment described above, in addition to the same operational effects as those of the above-described first embodiment, the following operational effects can be obtained.
(11) The first distance measuring unit 13a and the second distance measuring unit 13b perform distance measurement at arbitrary positions on the imaging surface. Since this is done, the flexibility of the distance measuring position is improved.

(12) The pixel 303 has a single output section 50. Since it did in this way, the circuit structure of the imaging part 12 is simplified and the manufacture of the imaging part 12 becomes easy.

The following modifications are also within the scope of the present invention, and one or more modifications can be combined with the above-described embodiment.

(Modification 1)
In the first embodiment, both the first distance measuring pixel 302a and the second distance measuring pixel 302b may have both the photodiode PDa and the photodiode PDb. In this case, the gate electrode 47 and the wiring 48 are provided in the lower layer of the layer in which the photodiode PDa and the photodiode PDb are formed with the imaging unit 12 having a two-layer structure. In this way, the light blocking member 42 is unnecessary, and the efficiency of using incident light is improved. The third distance measuring pixel 302c and the fourth distance measuring pixel 302d can be similarly configured.

(Modification 2)
In each of the above-described embodiments, the distance measurement by the first distance measuring unit 13a and the distance measurement by the second distance measuring unit 13b are exclusively performed, but these two methods of distance measurement may be performed at the same time. That is, the distance measurement of the phase difference method and the distance measurement of the TOF measurement method may be performed in parallel (or sequentially) on the photoelectric conversion signal based on the reflected light flux 4 and both results may be obtained. When the photoelectric conversion signal read from the first output unit 51 and the photoelectric conversion signal read from the second output unit 52 are added when performing the distance measurement of the TOF measurement method, it can be used for the distance measurement of the phase difference method. Become a signal. In this case, the focus adjustment unit 13d may perform focus adjustment based on one of the distance measurement results, or may perform focus adjustment based on an average distance of both distance measurement results.

(Modification 3)
In each of the above-described embodiments, the result of distance measurement by the first distance measuring unit 13a and the result of distance measurement by the second distance measuring unit 13b are used for focus adjustment, but the result of distance measurement is used for a different purpose. You may use it. For example, a so-called depth map in which the distance of the object to be measured 2 is two-dimensionally mapped may be created, or may be used to create a stereoscopic image of the object to be measured 2.

(Modification 4)
The receiving circuit 53 may be different from that shown in FIG. For example, the receiving circuit 54 shown in FIG. 12A clamps the feedthrough period immediately after resetting the imaging pixel 30 by the input capacitor 541 and the switch 542. After that, the photoelectric conversion signal is input to the amplifier 544 through the switch 543. The AD converter 546 converts the output signal of the amplifier 544 into a digital value. As another example, the receiving circuit 55 shown in FIG. 12B inputs the feedthrough period and the photoelectric conversion signal immediately after resetting the imaging pixel 30 to the amplifier 553 via the switch 551 and the switch 552, respectively. The AD converter 556 converts the output signal of the amplifier 553 into a digital value. As a result, the reset signal and the photoelectric conversion signal are individually converted into digital values. The control unit 13 removes the noise component by subtracting the former digital value from the latter digital value.

(Modification 5)
A circuit different from a part of the first output section 51 and the second output section 52 may be arranged below the light blocking member 42. For example, a part of the functions of the control unit 13 such as the first distance measuring unit 13a and the second distance measuring unit 13b may be incorporated in the lower portion of the light shielding member 42 as an electronic circuit.

(Modification 6)
The light blocking member 42 may be made of a material that absorbs light. In this case, the incident light is absorbed by the light shielding member 42, and as a result, it does not reach the circuit therebelow.

(Modification 7)
In each of the above-described embodiments, the image pickup device in which incident light is photoelectrically converted by the photodiode has been described. It is also possible to use this as an image pickup device that performs photoelectric conversion with a photoelectric conversion film formed of an organic material, for example.

The image pickup apparatus according to the present embodiment is not limited to the above-described image pickup apparatus 1. For example, the present embodiment can be applied to a lens-integrated digital still camera, film still camera, or video camera. Furthermore, the present embodiment can be applied to a small camera module built in an electronic device such as a mobile phone, a smart phone, and a tablet PC, a visual recognition device for a surveillance camera or a robot, and a vehicle-mounted camera.

The present invention is not limited to the above-described embodiments as long as the characteristics of the present invention are not impaired, and other forms considered within the scope of the technical idea of the present invention are also included in the scope of the present invention. ..

DESCRIPTION OF SYMBOLS 1... Imaging device, 10... Light source part, 11... Optical system, 12... Imaging part, 13... Control part, 13a... 1st ranging part, 13b... 2nd ranging part, 13c... Photometric part, 13d... Focus adjustment Department

Claims (13)

A first photoelectric conversion unit that photoelectrically converts light from a subject that has passed through a first pupil region of the optical system to generate electric charges, and a first photoelectric conversion unit that outputs a signal based on the electric charges generated by the first photoelectric conversion unit. A second pixel, which has a first pixel having an output section and a second output section, and photoelectric conversion of light from the subject that has passed through a second pupil area different from the first pupil area to generate an electric charge. And an imaging unit having a second pixel having a third output unit and a fourth output unit that output a signal based on the charges generated by the second photoelectric conversion unit,
A first distance measuring unit that measures a distance to the subject based on a signal output from the first output unit and a signal output from the third output unit;
At least one of the signal output from the first output unit and the signal output from the second output unit, and the signal output from the third output unit and the signal output from the fourth output unit And a second distance measuring unit that measures the distance to the subject based on the electronic device. The electronic device according to claim 1,
The first distance measuring unit is based on a deviation between an image of the subject in the first pupil region received by the first pixel and an image of the subject in the second pupil region received by the second pixel. And measure the distance to the subject,
The second distance measuring unit emits light from the light emitting unit and signals output from the first output unit and the second output unit based on electric charges obtained by photoelectrically converting the light emitted from the light emitting unit and reflected by the subject. Based on at least one of the signal output from the third output unit and the fourth output unit based on the electric charge obtained by photoelectrically converting the light reflected by the subject, the light emission from the light emitting unit is changed to the first pixel. An electronic device that measures a distance to the subject by detecting a time until light is received by at least one of the second pixels. The electronic device according to claim 2,
The first output unit outputs a signal based on the charges generated by the first photoelectric conversion unit between the first time and the second time, and the third output unit outputs the first time to the second time. To output a signal based on the charges generated by the second photoelectric conversion unit, and the second output unit generates the signal by the first photoelectric conversion unit between the second time and the third time. Outputting a signal based on charge, the fourth output unit outputs a signal based on charge generated by the second photoelectric conversion unit between the second time and the third time,
The second distance measuring unit, based on at least one of the signals output from the first output unit and the second output unit and the signals output from the third output unit and the fourth output unit, An electronic device for detecting a time from light emission to light reception in the light emitting unit. In the electronic device according to claim 2 or 3,
The second distance measuring unit has a difference in signal amount between the signal output from the first output unit and the signal output from the second output unit, and the signal output from the third output unit and the second output unit. An electronic device that detects a time from light emission to light reception in the light emitting unit based on a difference in signal amount of signals output from the output unit. The electronic device according to any one of claims 1 to 4,
A metering unit for metering the subject,
An electronic device, comprising: a control unit that controls the first distance measuring unit or the second distance measuring unit to perform measurement based on the amount of light measured by the light measuring unit. The electronic device according to claim 5,
When the light amount measured by the photometric unit exceeds a threshold value , the control unit performs measurement by the first distance measuring unit, and the light amount measured by the photometric unit does not exceed the threshold value. In this case, an electronic device that performs the measurement by the second distance measuring unit. The electronic device according to any one of claims 1 to 6,
An electronic device comprising a selection unit capable of selecting one of measurement by the first distance measurement unit and measurement by the second distance measurement unit. In the electronic device according to any one of claims 1 to 7,
The first pixel includes a first microlens, the first photoelectric conversion unit, and a first light blocking unit that blocks light that has passed through a region different from the first pupil region.
The said 2nd pixel is an electronic device which has a 2nd microlens, a 2nd photoelectric conversion part, and a 2nd light shielding part which shields the light which passed the area|region different from the said 2nd pupil area|region. The electronic device according to claim 8,
The first output section and the second output section are arranged in a range shielded by the first light shielding section, and the third output section and the fourth output section are arranged in a range shielded by the second light shielding section. Electronic equipment. A first photoelectric conversion unit that photoelectrically converts light from a subject that has passed through the first pupil region of the optical system to generate an electric charge, and a first photoelectric conversion unit that outputs a signal based on the electric charge generated by the first photoelectric conversion unit. A first pixel having an output section and a second output section, and a second photoelectric conversion that photoelectrically converts light from the subject that has passed through a second pupil area different from the first pupil area to generate an electric charge. And an imaging unit having a second pixel having a third output unit and a fourth output unit that output a signal based on the charges generated by the second photoelectric conversion unit,
A first distance measuring unit that measures a distance from the imaging unit to the subject based on a signal output from the first output unit and a signal output from the third output unit;
At least one of the signal output from the first output unit and the signal output from the second output unit, and the signal output from the third output unit and the signal output from the fourth output unit A second distance measuring unit that measures the distance to the subject based on
An electronic device comprising: a control unit capable of selecting one of measurement by the first distance measuring unit and measurement by the second distance measuring unit. The electronic device according to claim 10,
A metering unit for metering the subject,
An electronic device comprising: a control unit that controls to perform measurement by the first distance measuring unit or measurement by the second distance measuring unit based on the light amount measured by the light measuring unit. The electronic device according to claim 11,
When the light amount measured by the photometric unit exceeds a threshold value , the control unit performs measurement by the first distance measuring unit, and the light amount measured by the photometric unit does not exceed the threshold value. In this case, an electronic device that performs the measurement by the second distance measuring unit. The electronic device according to any one of claims 1 to 12,
The image capturing unit converts a light that has passed through the first pupil region and the second pupil region into a third photoelectric conversion unit that photoelectrically converts the light to generate an electric charge, and an electric charge generated by the third photoelectric conversion unit. A third pixel having an output section for outputting a signal based on
An electronic device comprising: a generation unit that generates image data based on a signal output from the output unit of the third pixel.

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