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CN-121986249-A - Self-mixing interferometry sensor device, method for operating a self-mixing interferometry sensor device, and electronic device

CN121986249ACN 121986249 ACN121986249 ACN 121986249ACN-121986249-A

Abstract

A self-mixing interferometry sensor apparatus includes a laser diode, a photodiode, a first sensing unit for generating a first sensing signal from a measurement signal of the photodiode, a second sensing unit for generating a second sensing signal from a junction voltage of the laser diode, and a switching unit adapted to generate an output signal from the first sensing signal in a first mode of operation and from the second sensing signal in a second mode of operation. The sensor device is adapted to switch between operating in a first mode of operation and operating in a second mode of operation.

Inventors

  • Javier miguel sanchez
  • Laurent Neiwu

Assignees

  • 艾迈斯-欧司朗股份有限公司

Dates

Publication Date
20260505
Application Date
20240808
Priority Date
20231018

Claims (19)

  1. 1. A self-mixing interferometry sensor apparatus (100) comprising: A laser diode (120), A photodiode (110), A first readout unit (210) for generating a first readout signal (211) from a measurement signal (111) of the photodiode (110), A second readout unit (220) for generating a second readout signal (221) from a junction voltage (121) of the laser diode (120), A switching unit (230) adapted to generate an output signal (231) from the first readout signal (211) in a first operating mode and to generate the output signal (231) from the second readout signal (221) in a second operating mode, Wherein the sensor device (100) is adapted to switch between operating in the first mode of operation and operating in the second mode of operation.
  2. 2. The sensor device (100) according to claim 1, Wherein the sensor device (100) is adapted to detect a signal bias of the first readout signal (211), Wherein the sensor device (100) is adapted to operate in the first operating mode if the signal bias is below a threshold value and in the second operating mode if the signal bias exceeds the threshold value.
  3. 3. Sensor device (100) according to one of the preceding claims, Wherein the sensor device (100) is adapted to receive a switching signal (235) for switching between operating in the first operating mode and operating in the second operating mode.
  4. 4. Sensor device (100) according to one of the preceding claims, Further comprising a driver circuit (240), the driver circuit (240) being arranged to operate the laser diode (120) with a first drive current (251) in the first mode of operation and to operate the laser diode (120) with a second drive current (252) in the second mode of operation, Wherein the first drive current (251) is higher than the second drive current (252).
  5. 5. Sensor device (100) according to one of the preceding claims, Wherein the switching unit (230) is adapted to generate the output signal (231) in the first operating mode from both the first readout signal (211) and the second readout signal (221).
  6. 6. Sensor device (100) according to one of the preceding claims, Wherein the laser diode (120) is a VCSEL.
  7. 7. Sensor device (100) according to one of the preceding claims, Wherein the first sensing unit (210) comprises a transimpedance amplifier (215).
  8. 8. Sensor device (100) according to one of the preceding claims, Wherein the sensor device (100) comprises an ASIC chip (130) arranged on a carrier (140).
  9. 9. The sensor device (100) according to claim 8, Wherein the laser diode (120) and the photodiode (110) are arranged adjacent to each other above the carrier (140).
  10. 10. Sensor device (100) according to one of claims 8 or 9, Wherein the photodiode (110) is integrated into the ASIC chip (130).
  11. 11. The sensor device (100) according to claim 8, Wherein the photodiode (110) and the laser diode (120) are integrated into a common chip (115).
  12. 12. The sensor device (100) according to one of claims 8 to 11, Wherein the laser diode (120) is arranged on the ASIC chip (130).
  13. 13. Sensor device (100) according to one of the preceding claims, Wherein the sensor device (100) is one of a force sensor, a particle sensor, a proximity sensor, an eye tracking sensor, a ranging sensor and an autofocus sensor.
  14. 14. A method for operating a self-mixing interferometry sensor apparatus (100), The sensor device (100) comprises a laser diode (120) and a photodiode (110), The method comprises switching between operating in a first mode of operation and operating in a second mode of operation, Wherein, the first working mode includes: -generating a first readout signal (211) from a measurement signal (111) of the photodiode (110); -generating an output signal (231) from the first readout signal (211); and the second operation mode includes: generating a second readout signal (221) as a function of a junction voltage (121) of the laser diode (120); -generating the output signal (231) from the second readout signal (221).
  15. 15. The method according to claim 14, Wherein the method comprises the following steps: detecting a signal bias of the first readout signal (211); operating in the first mode of operation if the signal bias is below a threshold; operating in the second mode of operation if the signal bias exceeds the threshold.
  16. 16. The method according to one of the claims 14 and 15, Wherein the method comprises the following steps: Receiving a switching signal (235); switching between operating in the first mode of operation and operating in the second mode of operation is performed in dependence on the switching signal (235).
  17. 17. The method according to one of the claims 14 to 16, Wherein, the first working mode includes: operating the laser diode (120) with a first drive current (251); and the second operation mode includes: operating the laser diode (120) with a second drive current (252); Wherein the first drive current (251) is higher than the second drive current (252).
  18. 18. The method according to one of the claims 14 to 17, Wherein, the first working mode includes: generating a second readout signal (221) as a function of a junction voltage (121) of the laser diode (120); the output signal (231) is generated from both the first readout signal (211) and the second readout signal (221).
  19. 19. An electronic device (10), comprising: the sensor device (100) according to one of claims 1 to 13.

Description

Self-mixing interferometry sensor device, method for operating a self-mixing interferometry sensor device, and electronic device The invention relates to a self-mixing interferometry sensor device, a method for operating a self-mixing interferometry sensor device and an electronic device. This patent application claims priority from German patent application 10 2023 128 608.0, the disclosure of which is incorporated herein by reference. Self-mixing interferometry sensor devices are known in the art. Document US 11,243,686 B2 describes an example of a self-mixing interference based sensor for characterizing user inputs. It is an object of the present invention to provide a self-mixing interferometry sensor apparatus. It is another object to provide a method for operating a self-mixing interferometry sensor apparatus. It is another object of the invention to provide an electronic device. These objects are achieved by a self-mixing interferometry sensor device, a method for operating a self-mixing interferometry sensor device and an electronic device as specified in the independent claims. Further variants are disclosed in the dependent claims. A self-mixing interferometry sensor apparatus includes a laser diode, a photodiode, a first sensing unit for generating a first sensing signal from a measurement signal of the photodiode, a second sensing unit for generating a second sensing signal from a junction voltage of the laser diode, and a switching unit adapted to generate an output signal from the first sensing signal in a first mode of operation and from the second sensing signal in a second mode of operation. The sensor device is adapted to switch between operating in a first mode of operation and operating in a second mode of operation. The sensor device enables the generation of an output signal based on a first readout signal generated from a measurement signal of a photodiode or based on a second readout signal generated from a junction voltage of a laser diode. Advantageously, this enables the generation of an output signal from a read-out signal providing a better signal quality. In particular, the output signal may be generated from the read-out signal providing a better signal-to-noise ratio. This may enable the sensor device to be adapted to situations where the background light hampers the quality of the signal transferred by the photodiode. Some variations of the sensor device are adapted to detect a signal bias of the first read-out signal. The sensor device is adapted to operate in a first mode of operation if the first signal bias is below the threshold value and in a second mode of operation if the signal bias exceeds the threshold value. Advantageously, this enables the sensor device to switch to generating an output signal based on a second readout signal generated from the junction voltage of the laser diode in case an excessive signal bias hampers the quality of the first readout signal generated from the measurement signal of the photodiode. Excessive signal bias may be caused by background light illuminating the photodiode. Some variations of the sensor device are adapted to receive a switching signal for switching between operating in the first mode of operation and operating in the second mode of operation. Advantageously, this enables the sensor device to be switched between the first and second operation modes by means of an external switching signal. This enables the sensor device to be adjusted to conditions that the sensor device cannot automatically detect. Some variations of the sensor device further include a driver circuit for operating the laser diode with a first drive current in a first mode of operation and with a second drive current in a second mode of operation. The first drive current is higher than the second drive current. Advantageously, this enables the sensor device to operate at an advantageous operating point in both the first and second operating modes. When the laser diode is operated with the first drive current instead of with the second drive current, the signal-to-noise ratio of the first readout signal generated from the measurement signal of the photodiode may be higher. When the laser diode is operated with the second driving current instead of the first driving current, the signal-to-noise ratio of the second readout signal generated according to the junction voltage of the laser diode may be higher. At the same time, the first readout signal may provide a better signal-to-noise ratio than the second readout signal when operating the laser diode with the first drive current, at least in the absence of excessive background light. The second readout signal may provide a higher signal-to-noise ratio than the first readout signal when the laser diode is operated with the second drive current. Operating the laser diode with the second drive current may provide the additional advantage of reduced power consumption of the sensor device. In some variations of