DISTANCE MEASUREMENT DEVICE AND DISTANCE MEASUREMENT SYSTEM

• US 20130250274A1
• Filed: 03/12/2013
• Published: 09/26/2013
• Est. Priority Date: 03/21/2012
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: KUROKAWA, YOSHIYUKI
• Granted Patent: US 9,541,386 B2
• Time in Patent Office: Days
• US Class Current: 356/5.01
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/10 using transmission of interrupted, pulse-modulated waves determination of distance by phase measurements G01S17/32
• CPC Class Codes: G01S 17/14 wherein a voltage or current pulse is initiated and terminated in accordance with the pulse transmission and echo reception respectively, e.g. using counters
• CPC Class Codes: G01S 17/18 wherein range gates are used
• CPC Class Codes: G01S 17/26 wherein the transmitted pulses use a frequency-modulated or phase-modulated carrier wave, e.g. for pulse compression of received signals
• CPC Class Codes: G01S 17/32 using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
• CPC Class Codes: G01S 17/34 using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
• CPC Class Codes: G01S 17/36 with phase comparison between the received signal and the contemporaneously transmitted signal
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4816 of receivers alone
• CPC Class Codes: G01S 7/4861 Circuits for detection, sampling, integration or read-out
• CPC Class Codes: H01L 31/02 Details

Abstract

A distance measurement device with high detection accuracy. The distance measurement device includes a photosensor including a light-receiving element, a first transistor, and a second transistor; a wiring; a signal line; and a power supply line. The wiring is electrically connected to one electrode of the light-receiving element. The signal line is electrically connected to a gate electrode of the first transistor. The power supply line is electrically connected to one of a source electrode and a drain electrode of the second transistor. One of a source electrode and a drain electrode of the first transistor is electrically connected to a gate electrode of the second transistor. The other of the source electrode and the drain electrode of the first transistor is electrically connected to the other electrode of the light-receiving element and the other of the source electrode and the drain electrode of the second transistor.

Claims

1. A semiconductor device comprising:

a photosensor comprising a light-receiving element, a first transistor, and a second transistor,

wherein a first electrode of the light-receiving element is electrically connected to a first terminal of the first transistor and a first terminal of the second transistor, and

wherein a gate electrode of the first transistor is electrically connected to a second terminal of the second transistor.

2. The semiconductor device according to claim 1,

wherein the first transistor comprises a channel formation region comprising an oxide semiconductor, and

wherein the second transistor comprises a channel formation region comprising an oxide semiconductor.

3. The semiconductor device according to claim 1,

wherein the photosensor comprises a third transistor, and

wherein a first terminal of the third transistor is electrically connected to the gate electrode of the first transistor and the second terminal of the second transistor.

4. The semiconductor device according to claim 1,

wherein the photosensor comprises a fourth transistor, and

wherein a gate electrode of the fourth transistor is electrically connected to the gate electrode of the first transistor and the second terminal of the second transistor.

5. The semiconductor device according to claim 1,

wherein the photosensor comprises a third transistor and a fourth transistor,

wherein a first terminal of the third transistor is electrically connected to the gate electrode of the first transistor and the second terminal of the second transistor, and

wherein a gate electrode of the fourth transistor is electrically connected to the gate electrode of the first transistor and the second terminal of the second transistor.

6. The semiconductor device according to claim 5,

wherein the first transistor comprises a channel formation region comprising an oxide semiconductor,

wherein the second transistor comprises a channel formation region comprising an oxide semiconductor, and

wherein the third transistor comprises a channel formation region comprising an oxide semiconductor.

7. The semiconductor device according to claim 1,

wherein the photosensor is configured to perform a reset operation by supplying a signal to a second electrode of the light-receiving element from a first time to a second time,

wherein a light source is configured to perform an irradiation of light to an object from the second time to a fourth time,

wherein the photosensor is configured to perform a detection of the light reflected off the object from the second time to the fourth time,

wherein the light source is configured to perform the irradiation n times,

wherein the photosensor is configured to perform the detection n times,

wherein a distance x from the semiconductor device to the object is obtained by:

8. The semiconductor device according to claim 1,

wherein a light source is configured to perform an irradiation of light to an object from a first time to a fourth time,

wherein the photosensor is configured to perform a reset operation by supplying a signal to a second electrode of the light-receiving element from a third time to the fourth time,

wherein the photosensor is configured to perform a detection of the light reflected off the object from the fourth time to a sixth time,

wherein the light source is configured to perform the irradiation n times,

wherein the photosensor is configured to perform the detection n times,

wherein a distance x from the semiconductor device and the object is obtained by:

9. The semiconductor device according to claim 1,

wherein the photosensor is configured to perform a first reset operation by supplying a signal to a second electrode of the light-receiving element from a first time to a second time,

wherein a light source is configured to perform a first irradiation of first light to an object from the second time to a fourth time,

wherein the photosensor is configured to perform a first detection of the first light reflected off the object from the second time to the fourth time,

wherein the light source is configured to perform a second irradiation of second light to the object from a twelfth time to a fifteenth time,

wherein the photosensor is configured to perform a second reset operation by supplying the signal to the second electrode of the light-receiving element from a fourteenth time to the fifteenth time,

wherein the photosensor is configured to perform a second detection of the second light reflected off the object from the fifteenth time to a seventeenth time,

wherein the light source is configured to perform the first irradiation n times,

wherein the light source is configured to perform the second irradiation n times,

wherein the photosensor is configured to perform the first detection n times,

wherein the photosensor is configured to perform the second detection n times,

wherein a distance x from the semiconductor device to the object is obtained by:

10. A semiconductor device comprising:

a first photosensor comprising a first light-receiving element, a first transistor, a second transistor, and a third transistor;

a second photosensor adjacent to the first photosensor, the second photosensor comprising a second light-receiving element, a fourth transistor, a fifth transistor, and a sixth transistor; and

a power supply line,

wherein a first electrode of the first light-receiving element is electrically connected to a first terminal of the first transistor and a first terminal of the second transistor,

wherein a gate electrode of the first transistor is electrically connected to a second terminal of the second transistor and a gate electrode of the third transistor,

wherein a first electrode of the second light-receiving element is electrically connected to a first terminal of the fourth transistor and a first terminal of the fifth transistor,

wherein a gate electrode of the fourth transistor is electrically connected to a second terminal of the fifth transistor and a gate electrode of the sixth transistor, and

wherein the power supply line is electrically connected to a second terminal of the first transistor and a second terminal of the fourth transistor.

11. The semiconductor device according to claim 10,

wherein the first transistor comprises a channel formation region comprising an oxide semiconductor,

wherein the second transistor comprises a channel formation region comprising an oxide semiconductor,

wherein the fourth transistor comprises a channel formation region comprising an oxide semiconductor, and

wherein the fifth transistor comprises a channel formation region comprising an oxide semiconductor.

12. The semiconductor device according to claim 10,

wherein the first photosensor is configured to perform a first reset operation by supplying a first signal to a second electrode of the first light-receiving element from a first time to a second time,

wherein a light source is configured to perform an irradiation of light to an object from the second time to a fifth time,

wherein the first photosensor is configured to perform a first detection of the light reflected off the object from the second time to the fifth time,

wherein the second photosensor is configured to perform a second reset operation by supplying a second signal to a second electrode of the second light-receiving element from a fourth time to the fifth time,

wherein the second photosensor is configured to perform a second detection of the light reflected off the object from the fifth time to a seventh time,

wherein the light source is configured to perform the irradiation n times,

wherein the first photosensor is configured to perform the first detection n times,

wherein the second photosensor is configured to perform the second detection n times,

wherein a distance x from the semiconductor device to the object is obtained by:

13. A semiconductor device comprising:

a first photosensor comprising a first light-receiving element, a second transistor, and a third transistor; and

a second photosensor comprising a second light-receiving element, a fourth transistor, a fifth transistor, and a sixth transistor,

wherein a first electrode of the first light-receiving element is electrically connected to a first terminal of the second transistor,

wherein a second terminal of the second transistor is electrically connected to a gate electrode of the third transistor,

wherein a first electrode of the second light-receiving element is electrically connected to a first terminal of the fourth transistor and a first terminal of the fifth transistor,

wherein a gate electrode of the fourth transistor is electrically connected to a second terminal of the fifth transistor and a gate electrode of the sixth transistor, and

wherein the first light-receiving element overlaps with the second light-receiving element.

14. The semiconductor device according to claim 13,

wherein the first light-receiving element is configured to detect visible light, and

wherein the second light-receiving element is configured to detect infrared light.

15. The semiconductor device according to claim 14,

wherein the second transistor comprises a channel formation region comprising an oxide semiconductor,

wherein the fourth transistor comprises a channel formation region comprising an oxide semiconductor, and

wherein the fifth transistor comprises a channel formation region comprising an oxide semiconductor.

16. The semiconductor device according to claim 14,

wherein the second photosensor is configured to perform a reset operation by supplying a signal to a second electrode of the second light-receiving element from a first time to a second time,

wherein a light source is configured to perform an irradiation of light to an object from the second time to a fourth time,

wherein the second photosensor is configured to perform a detection of the light reflected off the object from the second time to the fourth time,

wherein the light source is configured to perform the irradiation n times,

wherein the second photosensor is configured to perform the detection n times,

wherein a distance x from the semiconductor device to the object is obtained by:

17. The semiconductor device according to claim 14,

wherein a light source is configured to perform an irradiation of light to an object from a first time to a fourth time,

wherein the second photosensor is configured to perform a reset operation by supplying a signal to a second electrode of the second light-receiving element from a third time to the fourth time,

wherein the second photosensor is configured to perform a detection of the light reflected off the object from the fourth time to a sixth time,

wherein the light source is configured to perform the irradiation n times,

wherein the second photosensor is configured to perform the detection n times,

wherein a distance x from the semiconductor device and the object is obtained by:

18. The semiconductor device according to claim 14,

wherein the second photosensor is configured to perform a first reset operation by supplying a signal to a second electrode of the second light-receiving element from a first time to a second time,

wherein a light source is configured to perform a first irradiation of first light to an object from the second time to a fourth time,

wherein the second photosensor is configured to perform a first detection of the first light reflected off the object from the second time to the fourth time,

wherein the light source is configured to perform a second irradiation of second light to the object from a twelfth time to a fifteenth time,

wherein the second photosensor is configured to perform a second reset operation by supplying the signal to the second electrode of the second light-receiving element from a fourteenth time to the fifteenth time,

wherein the second photosensor is configured to perform a second detection of the second light reflected off the object from the fifteenth time to a seventeenth time,

wherein the light source is configured to perform the first irradiation n times,

wherein the light source is configured to perform the second irradiation n times,

wherein the second photosensor is configured to perform the first detection n times,

wherein the second photosensor is configured to perform the second detection n times,

wherein a distance x from the semiconductor device to the object is obtained by: