Laser photoplotter, referred to as photoplotter, is a phototypesetting product integrating laser optical technology, microelectronic technology and ultra-precision machinery. It is used to draw various graphics, images, text or symbols on photosensitive film.

Work principle

The laser photoplotter uses a laser to scan the film to generate graphics, and its principle is the same as the electron gun in the TV picture tube scans the fluorescent material on the screen. First, the image of the printed circuit board is mapped into a large storage array, and then the laser beam is turned on or off (modulated) according to the value of the corresponding cell in the storage array, thereby obtaining the required process film. Laser photoplotters use lasers as the light source, which has the advantages of easy focusing and energy concentration, and is very beneficial for instant and fast exposure of negatives. The exposure adopts scanning type, no matter how high the density is, the exposure can be completed in the shortest time, and it only takes a few minutes to draw a negative. Therefore, it has become the mainstream of today’s light painting industry.
The light source of laser photoplotter mostly uses gas lasers , such as argon, helium and neon. The light source of the gas laser has a high intensity but a limited lifespan, about 6000-10000h, so the light source needs to be replaced after more than one year of use. Some photoplotter manufacturers use semiconductor lasers as light sources, but the production of higher-power semiconductor lasers is not yet mature.

Process 

The design data generated by CAD is converted into light drawing data (mostly Gerber data) and processed by the CAM system to complete the light drawing preprocessing (imposition, mirroring, etc.). The processed data is sent to the photoplotter, and is converted into raster data by the raster data processor of the photoplotter, and the raster data directly drives the laser photoplotter to complete the photoplotting.