Camera with superimpose display device

• US 5,734,428 A
• Filed: 03/03/1995
• Issued: 03/31/1998
• Est. Priority Date: 03/04/1994
• Status: Expired due to Term

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Tanaka, Masayuki, Terashima, Jun, Nakagawa, Kazuyuki, Suda, Yasuo
• Primary Examiner(s): Peng, John K.
• Assistant Examiner(s): Srivastava, Vivek
• Application Number:
  US08/398,130
• Time in Patent Office: 1,124 Days
• Field of Search: 354/409, 354/408, 354/84, 354/143, 348/341, 348/232
• US Class Current: 348/341
• CPC Class Codes: G03B 13/02 Viewfinders
• CPC Class Codes: G03B 17/20 visible in viewfinder
• CPC Class Codes: G03B 19/12 Reflex cameras with single objective and a movable reflector or a partly-transmitting mirror
• CPC Class Codes: G03B 2213/025 Sightline detection

Abstract

There is disclosed a superimpose device for a single-lens reflex camera, which has a finder optical system including a focusing screen, a pentagonal roof type prism, and an eyepiece lens, a reflection plate which is arranged near the prospective imaging plane the finder optical system, and has micro-prisms forming a display portion, a plurality of light sources arranged near the vertex of the prism, and a projection optical element for deflecting illumination light from each light source by a reflection surface, and projecting the deflected light toward a front upper portion of the prism. The display portion illuminated with the illumination light via the prism, and light reflected by the display portion is guided to the eyepiece lens.

Claims

1. A camera or camera body comprising:

a finder optical system including a pentagonal roof type optical element having a front upper portion, and an eyepiece lens unit;

display portion carrying means arranged in said finder optical system below said pentagonal roof type optical element, and having a display portion, said display portion being arranged in an optical path of the finder optical system;

a light source which is arranged over said pentagonal roof type optical element and emits illumination light; and

a projection optical element for directing illumination light from said light source toward the display portion via the front upper portion of said pentagonal roof type element.

2. A camera or camera body according to claim 1, wherein said projection optical element has two reflection surfaces.

3. A camera or camera body according to claim 2, wherein said projection optical element has a lens function at a light exit end.

4. A camera or camera body according to claim 1, wherein a plurality of display portions are arranged in the optical path of the finder optical system, and a plurality of light sources are arranged over said pentagonal roof type optical element in correspondence with said plurality of display portions.

6. A camera or camera body according to claim 1, further comprising:

holding means for detachably holding said display portion carrying means.

7. A camera or camera body according to claim 1, wherein said finder optical system has a focusing screen.

5. A camera or camera body according to claim further comprising:

an outer case which covers said pentagonal roof type optical element and has a connection portion for an electronic flash device on a rear portion of an upper surface thereof.

8. A camera or camera body comprising:

a finder optical system having a focusing screen, a pentagonal roof type optical element, and an eyepiece lens unit;

focusing screen holding means for detachably holding said focusing screen;

a display portion carrying member arranged adjacent to said focusing screen and having a display portion;

carrying member holding means for detachably holding said display portion carrying member;

display portion illumination means for illuminating said display portion; and

shielding means for shielding said carrying member holding means from a photographing optical path,

wherein, when said shielding means is detached from said camera or camera body, both said focusing screen holding means and said carrying member holding means are releasable, and

when said shielding means is attached to said camera or camera body, only said focusing screen holding means is releasable.

9. A camera or camera body according to claim 8, wherein when said focusing screen is held by said focusing screen holding means, said display portion carrying member held by said carrying member holding means is prevented by said focusing screen or said focusing screen holding means from being detached.