Superimpose-plate for view finder

1. A superimpose-plate for a view finder, said superimpose-plate being on a focusing glass, on which a subject image obtained through the photographing optical system is formed, said superimpose-plate and said focusing glass being provided in an incident opening of a hollow pentagonal mirror, said superimpose-plate comprising:

a plurality of micro-prisms on said superimpose-plate;

each of said micro-prisms appearing as a triangle in a cross-section, the vertical angle of said triangle being identical in each of said micro-prisms, a ridgeline of each of said micro-prisms being parallel to the right-left direction of a picture plane of said view finder,

wherein an outline of at least one of said micro-prisms is a slender trapezoid when viewing said superimpose-plate from an upper side.

2. A superimpose-plate according to claim 1 , wherein said plurality of micro-prisms form at least one micro-prism group, each said micro-prism group corresponding to a mark to be indicated in said picture plane of said view finder.

3. A superimpose-plate according to claim 2 , wherein said micro-prism group comprises a relatively large first micro-prism and a relatively small second micro-prism.

4. A superimpose-plate according to claim 2 , wherein said micro-prism group comprises micro-prisms having the same shape and size.

5. A superimpose-plate according to claim 1 , wherein said micro-prisms project from a lower surface of said superimpose-plate.

6. A superimpose-plate for a view finder, said superimpose-plate being on a focusing glass, on which a subject image obtained through the photographing optical system is formed, said superimpose-plate and said focusing glass being provided in an incident opening of a hollow pentagonal mirror, said superimpose-plate comprising:

a plurality of micro-prisms on said superimpose-plate;

each of said micro-prisms appearing as a triangle in a cross-section, the vertical angle of said triangle being identical in each of said micro-prisms, a ridgeline of each of said micro-prisms being parallel to the right-left direction of a picture plane of said view finder,

wherein a ridgeline of at least one of said micro-prisms is at a slant relative to a surface of said superimpose-plate.

7. A superimpose-plate according to claim 6 , wherein a plurality of micro-prism groups, each of which comprises a plurality of said micro prisms, is provided, the inclination angles of said ridgelines of said plurality of micro-prism groups differing in accordance with a horizontal position of each said micro-prism group in a picture plane of said view finder.

8. A superimpose-plate according to claim 6 , wherein a plurality of micro-prism groups, each of which comprises a plurality of said micro prisms, is provided, the inclination angles of said ridgelines of said plurality of micro-prism groups aligned in a vertical direction in said picture plane of said view finder, being the same.

9. A superimpose-plate according to claim 6 , wherein said plurality of micro-prisms form at least one micro-prism group, each said micro-prism group corresponding to a mark to be indicated in said picture plane of said view finder.

10. A superimpose-plate according to claim 9 , wherein said micro-prism group comprises a relatively large first micro-prism and a relatively small second micro-prism.

11. A superimpose-plate according to claim 9 , wherein said micro-prism group comprises micro-prisms having the same shape and size.

12. A superimpose-plate according to claim 6 , wherein said micro-prisms project from a lower surface of said superimpose-plate.

13. A superimpose-plate for a view finder, said superimpose-plate being on a focusing glass, on which a subject image obtained through the photographing optical system is formed, said superimpose-plate and said focusing glass being provided in an incident opening of a hollow pentagonal mirror, said superimpose-plate comprising:

a micro-prism group comprising a plurality of micro-prisms on a surface of said superimpose-plate;

said micro-prism group having a first prism row, comprising a plurality of first micro-prisms which are arranged adjacent to each other and in a horizontal direction in a picture plane of said view finder, and a second prism row,—comprising a plurality of second micro-prisms which are located at a position between two adjacent first micro-prisms, said first prism row and said second prism row being arranged alternately in a vertical direction in said picture plane of said view finder.

14. A superimpose-plate according to claim 13 , wherein said micro-prism group corresponds to a mark to be indicated in said picture plane of said view finder.

15. A superimpose-plate according to claim 13 , wherein said first micro-prism is larger than said second micro-prism.

16. A superimpose-plate according to claim 13 , wherein said first micro-prism is the same size as said second micro-prism.

17. A superimpose-plate according to claim 13 , wherein an outline of said first micro-prism is a slender trapezoid, when viewing said superimpose-plate from an upper side.

18. A superimpose-plate according to claim 17 , wherein, in said first prism row, an upper side of the trapezoid of a third micro-prism, positioned at the center of said row, is in contact with a lower side of the trapezoid of a fourth micro-prism, adjacent to said third micro-prism, and a lower side of the trapezoid of said third micro-prism is in contact with an upper side of the trapezoid of a fifth micro-prism, adjacent to said third micro-prism.

19. A superimpose-plate according to claim 13 , wherein an outline of said second micro-prism is a slender trapezoid, when viewing said superimpose-plate from an upper side.

20. A superimpose-plate according to claim 19 , wherein said second prism row comprises a plurality of said second micro-prisms, and in said second prism row, a lower side of the trapezoid of a third micro-prism, positioned at a left side, is in contact with an upper side of the trapezoid of a fourth micro-prism, positioned at a right side.

21. A superimpose-plate according to claim 13 , wherein said micro-prisms project from a lower surface of said superimpose-plate.