NIGHT-VISION IMAGING APPARATUS, CONTROL METHOD OF THE SAME, AND HEADLIGHT MODULE

• US 20080029701A1
• Filed: 07/06/2007
• Published: 02/07/2008
• Est. Priority Date: 07/25/2006
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: UEDA, Daisuke, ONOZAWA, Kazutoshi
• Granted Patent: US 7,579,593 B2
• Time in Patent Office: Days
• US Class Current: 250/332
• CPC Class Codes: B60Q 1/0023 the element being a sensor, e.g. distance sensor, camera
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/4918 Controlling received signal intensity, gain or exposure of sensor
• CPC Class Codes: G01S 7/493 Extracting wanted echo signals
• CPC Class Codes: G01S 7/499 using polarisation effects
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H01L 27/148 Charge coupled imagers individual charge coupled devices H01L29/765

Abstract

The invention provides a night-vision imaging apparatus including: a light emission unit that emits infrared light; a solid-state imaging device that converts the infrared light into a first signal; a light-emission control unit that allows the light emission unit to emit the infrared light which is modulated according to a temporally pseudo-random first modulation; and an extraction unit that extracts, according to the first modulation, a signal corresponding to the infrared light emitted by the light emission unit from the first signal.

Claims

1. A night-vision imaging apparatus comprising:

a light emission unit operable to emit infrared light;

a solid-state imaging device operable to convert the infrared light into a first signal;

a light-emission control unit operable to allow said light emission unit to emit the infrared light which is modulated according to a temporally pseudo-random first modulation; and

an extraction unit operable to extract, according to the first modulation, a signal corresponding to the infrared light emitted by said light emission unit from the first signal.

2. The night-vision imaging apparatus according to claim 1, said night-vision imaging apparatus further comprising

a pulse generation unit operable to generate a pulse signal modulated in a temporally pseudo-random manner using a spread spectrum system,

wherein said light-emission control unit is operable to allow said light emission unit to emit the infrared light at a timing of change of the pulse signal, and

said extraction unit is operable to extract the signal corresponding to the infrared light emitted by said light emission unit from the first signal at the timing of change of the pulse signal.

3. The night-vision imaging apparatus according to claim 1,

wherein said light emission unit is operable to emit first infrared light and second infrared light,

said solid-state imaging device includes:

a first pixel which converts the first infrared light into the first signal; and

a second pixel which converts the second infrared light into a second signal,

said light-emission control unit is operable to allow said light emission unit to emit the first infrared light which is modulated according to the temporally pseudo-random first modulation, and is operable to allow said light emission unit to emit the second infrared light which is modulated according to a temporally pseudo-random second modulation different from the first modulation, and

said extraction unit is operable to extract, according to the first modulation, a signal corresponding to the first infrared light emitted by said light emission unit from the first signal, and is operable to extract, according to the second modulation, a signal corresponding to the second infrared light emitted by said light emission unit from the second signal.

4. The night-vision imaging apparatus according to claim 3,

wherein the first modulation and the second modulation are temporally opposite to each other.

5. The night-vision imaging apparatus according to claim 3,

wherein said light emission unit includes:

a first infrared LED which emits the first infrared light which is infrared light at a first wavelength; and

a second infrared LED which emits the second infrared light which is infrared light at a second wavelength different from the first wavelength,

said first pixel converts infrared light at the first wavelength into the first signal, and

said second pixel converts infrared light at the second wavelength into the second signal.

6. The night-vision imaging apparatus according to claim 3,

wherein said light emission unit is operable to emit the first infrared light linearly polarized in a first direction, and the second infrared light linearly polarized in a second direction different from the first direction,

said first pixel converts, into the first signal, the infrared light linearly polarized in the first direction, and

said second pixel converts, into the second signal, the infrared light linearly polarized in the second direction.

7. The night-vision imaging apparatus according to claim 6,

wherein the first direction is orthogonal to the second direction.

8. The night-vision imaging apparatus according to claim 6,

wherein said light emission unit includes:

a first infrared LED which emits infrared light;

a first polarization unit operable to linearly polarize, in the first direction, the infrared light emitted by said first infrared LED;

a second infrared LED which emits infrared light; and

a second polarization unit operable to linearly polarize, in the second direction, the infrared light emitted by said second infrared LED.

9. The night-vision imaging apparatus according to claim 6,

wherein said light emission unit includes:

an infrared LED which emits infrared light; and

a polarization unit operable to linearly polarize, in one of the first direction and the second direction, the infrared light emitted by said infrared LED.

10. The night-vision imaging apparatus according to claim 9,

wherein said polarization unit includes:

a polarization device operable to linearly polarize the infrared light emitted by said infrared LED; and

a rotation unit operable to rotate said polarization device to change a direction polarized by said polarization device to one of the first direction and the second direction.

11. The night-vision imaging apparatus according to claim 10,

wherein said rotation unit is operable to rotate said polarization device at a blanking period.

12. The night-vision imaging apparatus according to claim 9,

wherein said polarization unit includes:

a polarization device operable to linearly polarize the infrared light emitted by said infrared LED;

a liquid crystal device operable to shift a phase of the infrared light linearly polarized by said polarization device; and

a voltage application unit operable to change a voltage to be applied to said liquid crystal device to change an amount of shift of the phase shifted by said liquid crystal device.

13. The night-vision imaging apparatus according to claim 12,

wherein said voltage application unit is operable to change the voltage to be applied to said liquid crystal device at a blanking period.

14. The night-vision imaging apparatus according to claim 6, said night-vision imaging apparatus further comprising:

a detection unit operable to determine whether an intensity of at least one of the first signal and the second signal is equal to or more than a predetermined intensity; and

a light attenuation unit operable to attenuate infrared light received by said solid-state imaging device when said detection unit determines that the intensity of at least one of the first signal and the second signal is equal to or more than the predetermined intensity.

15. The night-vision imaging apparatus according to claim 14,

wherein said light attenuation unit includes:

a polarization device operable to transmit infrared light having a predetermined linear polarization component; and

a rotation unit operable to rotate said polarization device to attenuate the infrared light received by said solid-state imaging device.

16. The night-vision imaging apparatus according to claim 14,

wherein said light attenuation unit includes:

a liquid crystal device operable to shift a phase of infrared light received by said solid-state imaging device; and

a voltage application unit operable to change a voltage to be applied to said liquid crystal device to change an amount of shift of the phase shifted by said liquid crystal device.

17. The night-vision imaging apparatus according to claim 1, said night-vision imaging apparatus further comprising

a white LED which emits white light,

wherein said light emission unit is operable to light up when said white LED is on.

18. The night-vision imaging apparatus according to claim 1,

wherein said solid-state imaging device includes:

a first pixel which converts the infrared light into the first signal; and

a second pixel which converts light at a visible wavelength into a second signal.

19. The night-vision imaging apparatus according to claim 1,

wherein said solid-state imaging device includes:

a first pixel which has a sensitivity at a wavelength of infrared light;

a second pixel which has a sensitivity at a wavelength of red light;

a third pixel which has a sensitivity at a wavelength of green light; and

a fourth pixel which has a sensitivity at a wavelength of blue light.

20. The night-vision imaging apparatus according to claim 1,

wherein said light emission unit is used as a light source for a high beam.

21. The night-vision imaging apparatus according to claim 1,

wherein said solid-state imaging device includes a plurality of pixels, and

each of said pixels includes:

a light receiving device operable to receive at least one of infrared light and visible light; and

a light transmitting film having refractive index distribution formed on said light receiving device.

22. A headlight module mounted on a vehicle, comprising:

a light emission unit operable to emit infrared light;

a solid-state imaging device operable to convert the infrared light into a first signal;

a light-emission control unit operable to allow said light emission unit to emit the infrared light which is modulated according to a temporally pseudo-random first modulation; and

an extraction unit operable to extract, according to the first modulation, a signal corresponding to the infrared light emitted by said light emission unit from the first signal.

23. The headlight module according to claim 22,

wherein said light emission unit includes:

a first infrared LED which emits first infrared light; and

a second infrared LED which emits second infrared light,

said solid-state imaging device includes;

a first pixel which converts the first infrared light into the first signal; and

a second pixel which converts the second infrared light into a second signal,

said light-emission control unit is operable to allow said first infrared LED to emit the first infrared light which is modulated according to the temporally pseudo-random first modulation, and is operable to allow said second infrared LED to emit the second infrared light which is modulated according to a temporally pseudo-random second modulation different from the first modulation, and

said extraction unit extracts, according to the first modulation, a signal corresponding to the first infrared light emitted by said light emission unit from the first signal, and extracts, according to the second modulation, a signal corresponding to the second infrared light emitted by said light emission unit from the second signal,

said headlight module further comprises;

a first module which includes said first infrared LED and said second pixel and is installed in one of a right front side and a left front side of the vehicle; and

a second module which includes said second infrared LED and said first pixel and is installed in other than the right front side and the left front side of the vehicle.

24. A control method of a night-vision imaging apparatus including a light emission unit which emits infrared light and a solid-state imaging device which converts the infrared light into a first signal, said control method comprising:

allowing the light emission unit to emit the infrared light which is modulated according to a temporally pseudo-random first modulation; and

extracting, according to the first modulation, a signal corresponding to the infrared light emitted by the light emission unit from the first signal.