公开(公告)号：US20230113160A1

公开(公告)日：2023-04-13

申请号：US17563281

申请日：2021-12-28

Applicant: GOOGLE LLC

Inventor： Aurelien Jean Francois David ,  Bergen Albert Fletcher ,  Stuart James Myron Nicholson ,  Patrick F. Brinkley

IPC: H01S5/062 ,  H01S5/00 ,  H01S5/068

Abstract: A laser display system 100 is configured to increase the dynamic range of a laser diode by modulating an operating current applied to the laser diode based on a desired sequence of brightness levels and a temperature of the laser diode. In some embodiments, a measuring circuit measures a voltage of the laser diode at a given current, which indirectly indicates the temperature of the laser diode, thus obviating the need for a direct measurement of temperature. In addition, in some embodiments, the measuring circuit identifies a threshold current of the laser diode based on a range of current values at which values of the current multiplied by the derivative of the voltage against the current vary relatively rapidly. By compensating for temperature effects and identifying the threshold current, a driver of the laser diode more precisely controls light output of the laser diode across an increased dynamic range.

公开(公告)号：US20250004289A1

公开(公告)日：2025-01-02

申请号：US18697661

申请日：2022-09-29

Applicant: Google LLC

Inventor： Aurelien Jean Francois David ,  Benjamin Wales ,  Bergen Albert Fletcher ,  Daniel Adema ,  Daniel J. Effinger ,  Vance R. Morrison ,  Patrick F. Brinkley ,  Ian Andrews ,  Stuart James Myron Nicholson ,  Shreyas Potnis

IPC: G02B27/10 ,  G02B26/08 ,  G02B27/01 ,  G02B27/12

Abstract: A display system includes one or more low-power laser diodes, each producing an emission. The emissions are directed to an optical element that affects the direction or divergence of the emissions. The optical element redirects the emissions toward a steering element such as a MEMS-actuated mirror, or a combination of such mirrors. The steering element directs the emissions toward the incoupler of a waveguide acting as an optical combiner. The emissions propagate through the waveguide and are extracted by an outcoupler in the direction of an observer. By scanning the direction of the beam-steering element along one or several directions, an image may be formed.

公开(公告)号：US20240079851A1

公开(公告)日：2024-03-07

申请号：US17929880

申请日：2022-09-06

Applicant: Google LLC

Inventor： Daniel Malea ,  Bergen Albert Fletcher ,  Matthew Broga ,  Nathniel Ayalew

IPC: H01S5/068 ,  G02B26/10 ,  H01S5/00 ,  H01S5/06 ,  H01S5/062 ,  H01S5/40

CPC classification number: H01S5/068 ,  G02B26/101 ,  H01S5/0071 ,  H01S5/0617 ,  H01S5/062 ,  H01S5/40

Abstract: A laser display may include a light engine, which includes a laser diode and a temperature sensor configured to measure a temperature of the laser diode. The light engine may be coupled to a controller configured to determine a drive current for the laser diode to generate an optical power based on a threshold of the laser diode and an efficiency of the laser diode. The controller is configured to calculate the threshold and the efficiency of the laser diode at the measured temperature using a threshold model and an efficiency model of the laser diode, which are generated using a calibration process.