What is a Slide Projector?

Slide projector is an optical magnifying device that uses the principle of convex lens imaging to project pictures and other images on the screen. It consists of light source, condenser, projection lens and other components. According to the structure of the light path, it is divided into direct type (for transparent slides) and reflective type (for opaque books, pictures, etc.). According to the operation mode, it is divided into manual, automatic, remote control and audio-visual synchronization. Divided into single lens type and multi lens type according to the lens. Several slides can be mounted on the multi-lens slide projector at the same time, and the visual effect can be generated on the screen by manipulating the film changing mechanism and changing the lens during projection. ^[1]

slide projector

Slide projector and

German Jews in 1654

There are many types of slide projectors, but their basic structures and principles are roughly the same. Generally consists of four parts: optics, fuselage, mechanical transmission, and electrical control.

The optical part is the main component of the slide projector.

When using the slide projector, the airflow between the air inlet and the air outlet should be kept clear.

The industrial production of slide projectors began in 1845. The light source was also changed from oil candles to steam lamps, and finally to electric light sources. In order to improve the quality and brightness of the picture, a concave reflector is also installed behind the light source. The increase of the light source causes the temperature of the chassis to rise. For heat dissipation, an exhaust heat dissipation structure is installed in the slide projector. The film loss has also been changed to automatic.

The slide projectors we use today are developed and improved on the basis of 19th century slide projectors.