Image projection apparatus, projection image pattern, laser drive apparatus, camera apparatus
AssigneeSony Corporation
InventorMakibi Nakamura
Life of this patent
Estimating the term…
Abstract
Image projection apparatus wherein, a focusing lens is controlled when a shutter is operated so that a contrast signal, obtained when a luminance signal from a camera signal processing circuit is supplied to an auto focusing detection circuit, may become maximum. A laser diode is driven to generate laser beams that are condensed into parallel laser beams by a condenser. These parallel laser beams are applied to a hologram plate and thereby diffracted. The diffracted laser beams interfere with each other, to produce a hologram image with sufficient contrast. Therefore, satisfactory focusing can be made in an auto focus mode of the contrast detection system or in a manual focus mode.
Claims11
An imaging apparatus having imaging means for imaging an object, comprising:
- a laser light source for generating laser beams;
- image projection means for projecting onto the object a hologram which is obtained by applying the laser beams to a hologram plate;
- and
- focus control means for performing an auto focus operation of the imaging means by using the hologram image projected onto the object,
- wherein the projected hologram image is an image pattern comprised of a plurality of segments, with each segment including a predetermined number of light spots arrayed in a straight line;
- the first segment of the segments being provided in the center of the projected image;
- four of the second segments being provided at each vertex of a square that circumscribes a circle centered at the center of the first segment and has a predetermined length of diameter;
- and
- the power of the laser beams being such that the total heat of the first segment and the second segment is less than a level regulated by a predetermined laser beam safety standard.
Dependencies are inferred from the claim text.