Projector

projector

See front-projection TV and data projector.

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projector

1. an optical instrument that projects an enlarged image of individual slides onto a screen or wall

2. an optical instrument in which a strip of film is wound past a lens at a fixed speed so that the frames can be viewed as a continuously moving sequence on a screen or wall

3. a device for projecting a light beam

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projector [prə′jek·tər]

(engineering acoustics)

A horn designed to project sound chiefly in one direction from a loudspeaker.

An underwater acoustic transmitter.

(mathematics)

One of the lines or rays in a central projection.

(optics)

optical projection system

(ordnance)

Any apparatus for launching a projectile, such as a gun or rocket launcher.

Smooth-bore-type barrel or other unrifled weapon from which pyrotechnic signals, grenades, and certain mortar projectiles are fired.

A rack for launching target rockets.

Special type of gun for projecting antisubmarine projectiles.

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projector

1. A lighting unit which concentrates the light within a limited solid angle by means of mirrors and lenses; provides a high value of luminous intensity in one direction.

2. A line dropped perpendicularly from a point to a plane surface.

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Projector 

an optical device that forms an image of objects on a diffusing surface that serves as a screen. Projectors are classified as diascopic, episcopic, and epidiascopic, depending on the method used to illuminate the object.

In a diascopic projector, or diascope, an image is formed on a screen by light rays that pass through a transparent object, such as a diapositive or a motion-picture film (see Figure 1). Motion-picture projectors are a type of diascope in which the illuminated transparent object—the motion-picture film—is shifted in a specific manner in order to create the effect of motion on the screen. In a slide viewer, a transparent object is also illuminated by light rays passing through it, but the object itself is viewed through an eyepiece. Diascopes are the most numer

Figure 1. Optical diagram of a diascopic projector: (1) light source, (2) condenser, (3) diapositive, (4) lens, (5) screen

ous and varied type of projectors: there are diascopes for the printing of photographs, viewing diapositives, reading microfilms, and processing aerial photographs. In many modern diascopes, the focusing and changing of the diapositives is accomplished automatically, and the projector may be equipped for sound reproduction.

An episcopic projector (see Figure 2) forms an image of an opaque object on a screen by means of light rays that are reflected and scattered from the object. This category includes instruments for copying topographic maps and projecting illustrations.

Epidiascopic projectors use a combination of the diascopic and episcopic systems and can project images of both transparent and opaque objects.

Figure 2. Optical diagram of an episcopic projector: (1) light source, (2) reflector, (3) object to be projected, (4) lens, (5) mirror, (6) screen

A projector has both mechanical and optical components. The mechanical components provide for proper positioning of objects relative to the optical system, for changing the objects, and for controlling projection times. The optical components perform the projection process and consist of a lighting system with a light source and condenser and a projection lens.

REFERENCES

Volosov, D. S., and M. V. Tsivkin. Teoriia i raschet svetoopticheskikh sistem proektsionnykh priborov. Moscow, 1960.
[Ivanov, A. M.] Zarubezhnye liubitel’skie kadroproektory i diaskopy. Moscow, 1968.

A. M. IVANOV