ELECTRICAL MIXER AS REFERENCE PATH FOR TIME-OF-FLIGHT MEASUREMENT

• US 20190324128A1
• Filed: 04/19/2018
• Published: 10/24/2019
• Est. Priority Date: 04/19/2018
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: DIELACHER, Markus, FLATSCHER, Martin, GANSINGER, Stefan, VENUS, Alexander
• Granted Patent: US 10,591,588 B2
• Time in Patent Office: Days
• CPC Class Codes: G01S 17/32 using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/491 Details of non-pulse systems
• CPC Class Codes: G01S 7/4915 Time delay measurement, e.g. operational details for pixel components signal extraction and conditioning G01S7/493; Phase measurement
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating

Abstract

An imaging system may include a modulation component to provide a modulation signal. The imaging system may include an illumination component to receive the modulation signal and emit a modulated optical signal based on the modulation signal, and provide an electrical illumination signal. The electrical illumination signal may be an electrical representation of the modulated optical signal emitted by the illumination component. The imaging system may include an electrical mixer to receive the electrical illumination signal and the modulation signal, multiply the electrical illumination signal and the modulation signal in order to form a mixed signal, filter the mixed signal in order to form a filtered mixed signal, and output, based on the filtered mixed signal, a calibration signal associated with calibrating the imaging system.

Claims

1. An imaging system, comprising:

a modulation component to provide a modulation signal;

an illumination component to;

receive the modulation signal and emit a modulated optical signal based on the modulation signal; and

provide an electrical illumination signal,

wherein the electrical illumination signal is an electrical representation of the modulated optical signal emitted by the illumination component; and

an electrical mixer to;

receive the electrical illumination signal and the modulation signal;

multiply the electrical illumination signal and the modulation signal in order to form a mixed signal;

filter the mixed signal in order to form a filtered mixed signal; and

output, based on the filtered mixed signal, a calibration signal associated with calibrating the imaging system.

2. The imaging system of claim 1, further comprising a plurality of photosensitive pixels arranged to receive the modulated optical signal after the modulated optical signal is reflected by an object,

wherein the electrical mixer is not working on the principle used in the plurality of photosensitive pixels.

3. The imaging system of claim 2, wherein a magnitude of the filtered mixed signal is independent of an integration time associated with the plurality of photosensitive pixels.

4. The imaging system of claim 1, wherein the electrical mixer comprises an electrical circuit including an electrical non-linear element capable of multiplying the electrical illumination signal and the modulation signal.

5. The imaging system of claim 1, wherein the calibration signal is associated with compensating a delay between the modulation signal and the modulated optical signal.

6. The imaging system of claim 5, wherein the delay includes a temperature dependent delay of the illumination component in association with emitting the modulated optical signal.

7. The imaging system of claim 1, wherein the electrical mixer includes a logic gate to multiply the electrical illumination signal and the modulation signal.

8. The imaging system of claim 1, wherein the electrical mixer includes a low-pass filter associated with filtering the mixed signal.

9. The imaging system of claim 1, wherein the electrical mixer comprises a level shifter to adjust an amplitude of the electrical illumination signal before the electrical illumination signal and the modulation signal are multiplied.

10. The imaging system of claim 1, wherein the electrical mixer includes a reference generator to provide a set of reference signals to be compared to the filtered mixed signal in association with calibrating the imaging system.

11. The imaging system of claim 1, further comprising a calibration component to:

receive the calibration signal; and

calibrate the imaging system based on the calibration signal.

12. A system, comprising:

an electrical mixer to;

receive, from an illumination component of the system, an electrical illumination signal that is an electrical representation of a modulated optical signal emitted by the illumination component;

receive, from a modulation component of the system, a modulation signal associated with modulating an optical signal to form the modulated optical signal;

multiply the electrical illumination signal and the modulation signal in order to form a mixed signal;

filter the mixed signal in order to form a filtered mixed signal; and

provide, to a calibration component of the system and based on the filtered mixed signal, a calibration signal associated with calibrating the system.

13. The system of claim 12, further comprising a plurality of photosensitive pixels arranged to receive the modulated optical signal after the modulated optical signal is reflected by an object,

wherein the electrical mixer is not working on the principle used in the plurality of photosensitive pixels, and

wherein a magnitude of the filtered mixed signal is independent from an integration time associated with the plurality of photosensitive pixels.

14. The system of claim 12, wherein the electrical mixer comprises an electrical circuit capable of multiplying the electrical illumination signal and the modulation signal.

15. The system of claim 12, wherein the calibration signal is associated with compensating a delay between the modulation signal and the modulated optical signal,

wherein the delay includes a temperature dependent delay of the illumination component.

16. The system of claim 12, wherein the electrical mixer includes a logic gate to multiply the electrical illumination signal and the modulation signal.

17. The system of claim 12, wherein the electrical mixer includes a low-pass filter associated with filtering the mixed signal.

18. The system of claim 12, wherein the electrical mixer comprises:

a level shifter to adjust an amplitude of the electrical illumination signal; and

a reference generator to provide a set of reference signals to be compared to the filtered mixed signal in association with calibrating the system.

19. A method, comprising:

receiving, by an electrical mixer included in an imaging system, an electrical illumination signal that is an electrical representation of a modulated optical signal emitted by an illumination component of the imaging system;

receiving, by the electrical mixer, a modulation signal associated with forming the modulated optical signal;

mixing, by the electrical mixer, the electrical illumination signal and the modulation signal in order to form a mixed signal;

filtering, by the electrical mixer, the mixed signal in order to form a filtered mixed signal; and

providing, by the electrical mixer, a calibration signal based on the filtered mixed signal,

wherein the calibration signal is associated with calibrating the imaging system.

20. The method of claim 19, wherein a plurality of photosensitive pixels, associated with the imaging system, is arranged to receive the modulated optical signal after the modulated optical signal is reflected by an object,

wherein the electrical mixer is not working on the principle of the plurality of photosensitive pixels, and

wherein a magnitude of the filtered mixed signal is independent of an integration time associated with the plurality of photosensitive pixels.