Laser projector

Abstract

A laser projector steers a pulsed laser beam to form a pattern of stationary dots on an object, the pulsed laser beam having a periodicity determined based at least in part on a maximum allowable spacing of the dots and on a maximum angular velocity at which the beam can be steered, wherein a pulse width of the laser beam and a pulse peak power of the laser beam are based at least in part on the determined periodicity and on laser safety requirements.

What is claimed is: 
     
         1 . A device configured to be selectively coupled to a power mains, the device comprising:
 a beam-steering system operable to project a pattern of laser light onto an object, the beam-steering system including a first galvanometer operable to rotate a first mirror and a second galvanometer operable to rotate a second mirror, the first galvanometer further including a first angle transducer to measure a first angle of rotation of the first mirror, the second galvanometer including a second angle transducer to measure a second angle of rotation of the second mirror;   an optical detector is operably coupled to the beam-steering system that is configured to detect laser light reflected the object;   a processor is operable to determine features of the object based at least in part on the optical power of the reflected laser light and on the measured first angle and the measured second angle; and   a first battery is operably coupled to the beam-steering system, the optical detector, wherein the processor is configured to automatically provide electrical power to the device from the first battery in the absence of electrical power from the power mains.   
     
     
         2 . The device of  claim 1 , further comprising a second battery operable to provide electrical power to the device, wherein the first battery or the second battery may be removed from or placed into the device without first turning off power to the device. 
     
     
         3 . The device of  claim 1 , further comprising a supplemental backup battery providing temporary backup power to preserve device state information when electrical power is available from neither the battery nor the power mains. 
     
     
         4 . The device of  claim 3 , further comprising power management circuitry to balance electrical power extracted from the first battery and the second battery based at least in part on charge remaining in the first battery and the second battery. 
     
     
         5 . A method comprising:
 providing a system having a laser, a beam-steering system, an optical detector, and a first battery;   generating laser light with the laser;   projecting the laser light onto an object with the beam-steering system, the beam-steering system having a first galvanometer and a second galvanometer, the first galvanometer steering laser light off a first mirror and measuring a first angle of rotation of the first mirror, the second galvanometer steering the laser light off a second mirror and measuring a second angle of rotation of the second mirror;   detecting with the optical detector the laser light reflected from the object;   determining features of the object based at least in part on the optical power of the detected laser light and on the measured first and the measured second angle;   monitoring to determine whether the system is being provided with electrical power through a power mains; and   providing the system with electrical power the first battery when monitoring has determined that the power mains is not providing the system with electrical power.   
     
     
         6 . The method of  claim 5 , further comprising providing the electrical system with a second battery and providing the system with electrical power from the second battery. 
     
     
         7 . The method of  claim 6 , further comprising adding the second battery to the system or removing the second battery from the system without first turning off power to the system. 
     
     
         8 . The method of  claim 7 , further comprising:
 providing the system with a supplemental backup battery;   monitoring to determine whether the system is being electrical power from any source; and   providing the system with temporary backup power to preserve device state information when electrical power is not being provided to the system from any source.   
     
     
         9 . The method of  claim 5 , further comprising balancing electrical power extracted from the first battery and the second battery based at least in part on charge remaining in the first battery and the second battery. 
     
     
         10 . A device comprising
 a beam-steering system operable to project a pattern of laser light onto an object, the beam-steering system including a first galvanometer operable to rotate a first mirror and a second galvanometer operable to rotate a second mirror, the first galvanometer further including a first angle transducer to measure a first angle of rotation of the first mirror, the second galvanometer including a second angle transducer to measure a second angle of rotation of the second mirror;   an optical detector is operably coupled to the beam-steering system and is configured to detect laser light reflected the object;   a processor is operably coupled to the beam-steering system and optical detector, the processor being configured to detect features of the object based at least in part on the optical power of the reflected laser light and on the measured first angle and the measured second angle; and   a wireless communication system is operable to transmit and receive wireless data.   
     
     
         11 . The device of  claim 10 , wherein wireless communication system includes a Wi-Fi transceiver module based on the IEEE 802.11 family of standards, the Wi-Fi module operable to transmit and receive data wirelessly. 
     
     
         12 . The device of  claim 11 , wherein the Wi-Fi transceiver module is operable to communicate with a Wi-Fi device connected to a network. 
     
     
         13 . The device of  claim 12 , wherein the Wi-Fi transceiver module is further operable to communicate with a Wi-Fi device not connected to a network, the communication made through an access point on the device. 
     
     
         14 . The device of  claim 10 , wherein the wireless communication system includes a Bluetooth transceiver module operable to exchange data wirelessly with a Bluetooth enabled device. 
     
     
         15 . A device comprising:
 a beam-steering system operable to project a pattern of laser light onto an object, the beam-steering system including a first galvanometer operable to rotate a first mirror and a second galvanometer operable to rotate a second mirror, the first galvanometer further including a first angle transducer to measure a first angle of rotation of the first mirror, the second galvanometer including a second angle transducer to measure a second angle of rotation of the second mirror;   a first optical detector is operably coupled to the beam-steering system and is configured to detect laser light reflected the object;   a second optical detector is operably coupled to the beam-steering system to detect the laser light reflected from the object, the second optical detector having a higher sensitivity than the first optical detector;   a beam splitter positioned to send a first portion of the laser light reflected from the object to the first optical detector and to send a second portion of the laser light reflected from the object to the second optical detector;   a processor is operably coupled to the first optical detector, the second optical detector, and the beam-steering system, the processor being operable to detect features of the object based at least in part on the measured first angle, the measured second angle, and on at least one of the optical power of the first portion and the optical power of the second portion.   
     
     
         16 . The device of  claim 15 , wherein the sensitivity of the second optical detector is at least one hundred times higher than the sensitivity of the first optical detector. 
     
     
         17 . The device of  claim 16 , further comprising:
 a pinhole aperture;   a lens operable to focus the laser light reflected from the object; and   a pinhole adjustment mechanism operable to adjust the position of the pinhole aperture to pass the focused laser light to the beam splitter.   
     
     
         18 . The device of  claim 17 , further comprising a housing to hold the lens and the pinhole aperture, the housing being at least partially covered with a coating to suppress scattering of light between the lens and the pinhole aperture. 
     
     
         19 . The device of  claim 15 , further comprising a pinhole assembly, the pinhole assembly comprising
 a pinhole aperture,   a pinhole x-y adjustment mechanism having a first screw and a first spring that each push in a first direct direction against the pinhole aperture, the first spring arranged to apply a force opposing the push of the first screw, the pinhole x-y adjustment further having a second screw and a second spring that each push in a second direction against the pinhole aperture, the second direction being perpendicular to the first direction, the second spring arranged to apply a force opposing the push of the second screw;   a pinhole z-adjustment mechanism having a tube with external threads, a ring with internal threads, and a third spring, the ring being placed over the pinhole x-y adjustment mechanism and the third spring and then screwed onto the tube, the ring constraining a z-position of the pinhole x-y adjustment mechanism while providing access to the first screw and the second screw for adjusting the x-y position of the pinhole aperture.