Patent ID: 11906890
Assignee: HISENSE LASER DISPLAY CO., LTD
Field: Optics (Instruments)
Classification: CPC G  H | IPC G  H

Claim 0:
1. A laser projection apparatus, comprising a laser light source, a light combining mirror group, an optical path shaping lens, a diffusion wheel, a light collecting device, a light valve, a projection lens, a main control circuit, a diffusion wheel driving circuit and a temperature sensor, wherein
the laser light source is configured to emit laser beams of three colors;
the combining mirror group is configured to combine the laser beams of three colors;
the optical path shaping lens is configured to shape a light path of the combined laser beams; and the combined laser beams are transmitted to the optical path shaping lens and then incident to the diffusion wheel;
the diffusion wheel is configured to homogenize the laser beams and then transmit the laser beams to the light collecting device;
the light valve is configured to modulate light of each color into an image light beam and transmit the image light beam to the projection lens;
the projection lens is configured to project the image light beam onto a projection screen;
the diffusion wheel includes a motor and a diffusion portion, wherein the motor is a three-phase motor;
the temperature sensor is electrically connected to the main control circuit, and configured to detect an ambient temperature;
the main control circuit is configured to: determine a target starting current according to the ambient temperature; determine a duty cycle of a second startup pulse width modulation signal according to the target starting current, and provide the second startup pulse width modulation signal to the diffusion wheel driving circuit; and output an operating pulse width modulation signal to the diffusion wheel driving circuit when the diffusion wheel reaches a target rotation speed, wherein the target starting current is a minimum drive current required to drive the motor from standstill to starting to rotate, and the target rotation speed is a preset speed at which the diffusion wheel operates normally and speckles can be eliminated; and
the diffusion wheel driving circuit is configured to drive the three-phase motor to drive the diffusion portion in response to each of the second startup pulse width modulation signal and the operating pulse width modulation signal.