What is a primary function of the laser in a laser printer?

In a laser printer, the primary function of the laser is to create an electrostatic image on a drum. This process begins when the laser beam, directed by rotating mirrors and lenses, illuminates specific areas of a photosensitive drum. The laser selectively discharges certain areas of the drum, thereby forming a latent electrostatic image that corresponds to the text and images to be printed.

Once the electrostatic image is created, the printer applies toner (a fine powder) to the drum. The toner adheres only to the areas that were exposed to the laser light, thus allowing the image to be transferred to the paper during the printing process. This method of printing is precise and allows for high-quality output, which is why the creation of the electrostatic image by the laser is a crucial fundamental aspect of laser printer operation.