The blanking mechanism blocks those unwanted laser pointer beams. Most gas lasers place it behind the output window because the gas laser itself cannot quickly adjust the output power. An ammeter is used as a movable part of the blanking mechanism to drive the shutter. For multicolor laser systems, such as mixed gas lasers, an optical blanker, called a multicolor acousto-optic modulator (PCAOM), is used to control each spectral line. In addition to safety shutters, mechanical blankers are often omitted on PCAOM-based lasers or solid-state lasers that can be directly modulated.
The beam switcher is a mechanical system that directs the laser beam to a special special effect mirror, which inserts an optical filter on the optical path. Due to the low requirements for switching speed and switching, open-loop galvanometers, stepper motors, and solenoid valves can be used to change the optical path. Optical filters used in special effects mirrors expand and scatter laser beams, and some grating disks have the same effect. After the laser beam passes through the special effect mirror, it generates a scattered laser beam for beam performance or an abstract pattern for screen display.
The X-Y scanner is the most versatile component, and it can control the direction of the green laser pointer beam at will. The schematic diagram of the X-Y scanner is shown. The two galvanometers are installed in orthogonal directions. The incident laser beam is reflected by the X-axis and Y-axis galvanometers and emitted. The specific direction is given by the combination of the reflection angles of the two galvanometers. The scanner can draw a grid or a ring of laser light, and can also draw a laser pattern on the screen. For screen performance, the scanning frequency is very important, because to obtain high-quality images, it is necessary to scan as fast as possible to increase the frame rate. Only closed-loop galvanometers can meet the requirements of screen performance, and open-loop or resonant galvanometers can also be used in simple image generation.
In addition to the optical devices described above, other devices are needed, such as scan drivers. laser power supplies, laser cooling systems. display controllers, consoles, and so on. The laser projector is composed of these components.