Camera focussing aid
AssigneeMinolta Camera Kabushiki Kaisha
InventorsYoshio Kuramoto, Toshinori Imura, Yoshiiku Kikukawa
Life of this patent
Estimating the term…
Abstract
A camera focussing aid includes an auxiliary light projector directing a light beam forwardly of the camera and mounted in the camera body or in a separable flash unit. A mechanism is provided for deactivating the auxiliary projector during the camera exposure sequence and includes a switch network connecting the auxiliary projector lamp to a battery, the switch being opened either with the depression of the shutter release member, the initiation of the shutter opening, the closing of the flash triggering switch or a drop in voltage across the flash charge capacitor. The projector beam is advantageously of small divergence and the auxliary projector may be used with a camera having a split image range finder or a single lens reflex camera.
Claims30
An auxiliary illumination device for use with a photographic camera which includes a shutter and a view-finder having means for visibly indicating the focus condition of an image of a photographic object, and for use with a flash device which includes an electronic flash tube, a capacitor, means for charging said capacitor and a trigger circuit for discharging said capacitor for firing said electronic flash tube in synchronism with the opening of said shutter, said auxiliary illumination device comprising:
- an illumination lamp for projecting light on a part of the photographic object;
- a power supply circuit for supplying electric power to said illumination lamp;
- and
- means for permitting and interrupting the power supply to said illumination lamp respectively upon accomplishment of the charging and discharging of said capacitor.
An auxiliary illumination device for use with a photographic camera which includes a shutter, a focus adjusting member for adjusting focus condition of an image of a photographic object, and a view-finder having means for visibly indicating the focus condition of said image, said illumination device comprising:
- an illumination lamp for projecting light on a part of the photographic object;
- a power supplying circuit for supplying electric power to said illumination lamp;
- switching means disposed in said power supplying circuit and being normally non-conductive for interrupting the power supply to said illumination lamp;
- and
- manual means operable for rendering said switching means conductive, said manual means being disposed at a position in which the same is operable together with said focus adjusting member while the latter is being operated.
In a camera apparatus including a camera having a forwardly directed objective lens of adjustable focus, a shutter, an exposure mechanism for sequentially opening and closing said shutter, and a focus adjusting member for adjusting focus condition of an image of a photographic object, the improvement comprising:
- an auxiliary light projector forwardly directing a beam of light;
- means responsive to the operation of said exposure mechanism for deactivating said auxiliary light projector during the open condition of said shutter;
- means for converging said beam of light from said auxiliary light projector to form a light spot on a photographic object;
- and
- means for indicating focus condition of an image of said photographic object, said focus indicating means including a first and a second optical system spaced a given reference distance to each other and being capable of forming a virtual image of said photographic object respectively so that said virtual images formed by said first and second optical systems are superimposed with each other, and said second optical system including an optical system including an optical member adapted to move in association with the operation of said focus adjusting member so that said virtual image formed by said second optical system is moved relative to said virtual image formed by said first optical system and so that said virtual images superimposed with each other coincides with each other when focussing has been completed.
Dependencies are inferred from the claim text.