Compact imaging apparatus and projection display device

Abstract

Abstract A compact imaging apparatus and rear projection display device are described wherein an image of an object is focused on an image area which is displaced and rotated from the object plane. A pair of planar mirrors of predetermined shape are selectively located to fold the image beam from an image device and provide an image of desired orientation on the image area. A compact camera for producing a large image area in a small volume is described and is particularly useful in connection with so-called instantly developed photographic films. A rear projection device is described, having an optical arrangement which confers a high degree of immunity to ambient light. An image beam is projected upwardly against a first mirror, reflected toward a second mirror behind a projection screen, and then reflected forwardly to the projection screen. The display is highly immune to ambient light, since the general path of the image projection beam is always upward, whereas the general path of virtually all ambient light is downward. The use of two mirrors to fold the image beam in this manner introduces an unusual rotation of the projected image which, however, is taken into account in the design of the optical system. For the sake of ruggedness and precision, as well as economy of construction, the cabinet of a microform display device employing the described optical system is formed from a unitary block of polystyrene foam, the interior walls of which are faceted in an appropriate manner to provide mounting surfaces for the two mirrors. The same optical principle is applied also to the design of a combined electronic and optical display device enclosed within a CRT envelope, which is suitable for producing either an ephemeral read-out or hard copy.

Inventors

• 👤 Adnan Waly
• 👤 George J. Yevick

Bibliographic Details