Lens-fitted photographic film unit

Claim 2

A lens-fitted photographic film unit including at least first and second parts connected together, the film unit including a photo-taking mechanism and unexposed photographic film, the film unit further comprising: a claw structure formed on said first part for retaining said first part on said second part; and a receiving portion formed on said second part for receiving and unremovably retaining said claw structure, said receiving portion being readily broken away from said second part upon separation of said first and second parts and retained unremovably on said first part, thereby to provide on said first part the unremovably retained receiving portion as an indication that said first part has been used.

Claim 3

A lens-fitted photographic film unit as defined in claim 1, wherein said second part has a readily breakable portion near said receiving portion, the thickness of said readily breakable portion being such as to facilitate breakage of said receiving portion away from said second part.

Claim 4

A lens-fitted photographic film unit as defined in claim 1, wherein: said second part constitutes a main body incorporating said photo-taking mechanism and containing said unexposed film at the rear thereof; and said first part is a rear cover for covering a bottom and the rear of said main body in light-tight fashion.

Claim 5

A lens-fitted photographic film unit as defined in claim 3, further comprising a front cover removably secured to the front of said main body.

Claim 6

A lens-fitted photographic film unit as defined in claim 3, wherein: said main body includes a film-containing section of plastic and a photo-taking section secured in front of said film-containing section; said film-containing section contains said unexposed film and a cassette for taking up said film after exposure, and has said receiving portion formed thereon; and said photo-taking section includes said photo-taking mechanism.

Claim 7

A lens-fitted photographic film unit as defined in claim 5, wherein said photo-taking section is removably secured to said film-containing section.

Claim 8

A lens-fitted photographic film unit as defined in claim 5, wherein a wind-up wheel is rotatably mounted on said film-containing section for winding up said film.

Claim 9

A lens-fitted photographic film unit as defined in claim 7, wherein said receiving portion is a portion of a reversal-preventing claw which projects from said film-containing section in a shape of a thin plate for preventing said wind-up wheel from rotating in a direction opposite to the direction for winding up said film in said cassette.

Claim 10

A lens-fitted photographic film unit as defined in claim 8, wherein: said claw structure includes first and second retaining hooks that face each other; and said retaining hooks each have a portion projecting from said rear cover substantially erectly, and a hooking portion projecting laterally from an end of said projecting portion and engaging an edge of said reversal-preventing claw.

Claim 11

A lens-fitted photographic film unit as defined in claim 9, wherein said rear cover has a pair of contact projections disposed transversely of said first and second retaining hooks for clamping said reversal-preventing claw so as to keep said first and second hooking portions in contact with said reversal-preventing claw.

Claim 12

A lens-fitted photographic film unit as defined in claim 7, wherein: said receiving portion is a receiving hole formed in a reversal-preventing claw which projects from said film-containing section in the shape of a plate for preventing said wind-up wheel from rotating in a direction opposite to the direction winding up said film in said cassette; and said readily breakable portion is a groove formed between said receiving hole and said film-containing section.

Claim 13

A lens-fitted photographic film unit as defined in claim 11, wherein: said claw structure includes first and second retaining hooks arranged back to back; and said retaining hooks respectively have a portion projecting from said rear cover substantially erectly, and a hooking portion projecting laterally from an end of said projecting portion and engaging an edge of said receiving hole.

Claim 14

A lens-fitted photographic film unit as defined in claim 1, wherein: said first part constitutes a main body including said photo-taking mechanism and containing said unexposed film at its rear; and said second part is a rear cover for covering the bottom and rear of said main body in light-tight fashion.

Claim 15

A lens-fitted photographic film unit as defined in claim 13, further comprising a front cover removably secured to the front of said main body.

Claim 16

A lens-fitted photographic film unit including a photo-taking mechanism and unexposed photographic film, comprising: a main body carrying said photo-taking mechanism and containing said unexposed film at the rear thereof; a plastic rear cover for covering the rear of said main body in light-tight fashion; a claw structure formed on said rear cover for retaining said rear cover on said main body; and a receiving portion formed on said main body and unremovably retained on said claw structure, said receiving portion being readily broken away from said main body and retained on said claw structure upon separation of said rear cover from said main body, the receiving portion retained on said claw structure serving as an indication that said rear cover has been used.

Claim 17

A lens-fitted photographic film unit including a photo-taking mechanism and unexposed photographic film, comprising: a main body carrying said photo-taking mechanism and containing said unexposed film at the rear thereof; a plastic rear cover for covering the rear of said main body in light-tight fashion; a claw structure formed on said rear cover for retaining said rear cover on said main body; and a receiving portion formed on said main body and unremovably retained on said claw structure, said receiving portion being readily broken away from said main body and retained on said claw structure upon separation of said rear cover from said main body, the receiving portion retained on said claw structure serving as an indication that said rear cover has been used.

Claim 18

A lens-fitted photographic film unit as defined in claim 15, wherein a wind-up wheel is rotatably mounted on said main body for winding up said film.

Claim 19

A lens-fitted photographic film unit as defined in claim 16, wherein said main body has a reversal-preventing claw for preventing said wind-up wheel from rotating in a direction opposite to the direction for winding up said film, and said receiving portion is formed on said reversal-preventing claw.

Claim 20

A lens-fitted photographic film unit including a photo-taking mechanism and unexposed photographic film, comprising: a main body carrying said photo-taking mechanism and containing said unexposed film at the rear thereof; a plastic rear cover for covering the rear of said main body in light-tight fashion; a wind-up wheel rotatably mounted on said main body for winding up said film; a reversal-preventing claw formed integrally with said main body and engaged with said wind-up wheel, for preventing said wind-up wheel from rotating in a direction opposite to a direction for winding up said film; a retaining claw structure formed on said rear cover and engaged with said reversal-preventing claw, for retaining said rear cover on said main body; the engagement between said retaining claw structure and said reversal-preventing claw being such that when said rear cover is removed from said main body, said reversal-preventing claw is disengaged from said wind-up wheel to allow reverse rotation of said wind-up wheel.

Claim 21

A lens-fitted photographic film unit including a photo-taking mechanism and unexposed photographic film, comprising: a main body carrying said photo-taking mechanism and containing said unexposed film at the rear thereof; a plastic rear cover for covering the rear of said main body in light-tight fashion; a wind-up wheel rotatably mounted on said main body for winding up said film; a reversal-preventing claw formed integrally with said main body and engaged with said wind-up wheel, for preventing said wind-up wheel from rotating in a direction opposite to a direction for winding up said film; a retaining claw structure formed on said rear cover and engaged with said reversal-preventing claw, for retaining said rear cover on said main body; the engagement between said retaining claw structure and said reversal-preventing claw being such that when said rear cover is removed from said main body, said reversal-preventing claw is disengaged from said wind-up wheel to allow reverse rotation of said wind-up wheel.

Claim 22

A lens-fitted photographic film unit as defined in claim 18, wherein said disengagement of said reversal preventing claw from said wind-up wheel is effected by said retaining claw breaking said reversal-preventing claw off of said main body.