Self-developing photo film unit with trap member for trapping surplus developing solution

A self-developing photo film unit having a photosensitive sheet, a cover sheet, a mask sheet and a trap member, said photosensitive sheet being secured to said mask sheet to close an aperture in said mask sheet, said cover sheet being opposed to said photosensitive sheet, said mask sheet having first and second edge portions bent back to wrap edges of said photosensitive sheet and said mask sheet, and having edge lines secured to said cover sheet, said trap member being secured to said first edge portion, being positioned on said photosensitive sheet and/or said mask sheet, and trapping a surplus part of developing solution spread between said photosensitive sheet and said mask sheet, said self-developing photo film unit comprising:

• said trap member comprising a chip of non-woven fabric being produced by a wet process, having a porosity of 70% or more, having acid polymer impregnated therein, and including fibres, and said fibres including 3-20 wt. % of pulp.

A self-developing photo film unit having a photosensitive sheet, a cover sheet, a mask sheet and a trap member, said photosensitive sheet being secured to said mask sheet to close an aperture in said mask sheet, said cover sheet being opposed to said photosensitive sheet, said mask sheet having first and second edge portions bent back to wrap edges of said photosensitive sheet and said mask sheet, and having edge lines secured to said cover sheet, said trap member being secured to said first edge portion, being positioned on said photosensitive sheet and/or said mask sheet, and trapping a surplus part of developing solution spread between said photosensitive sheet and said mask sheet, said self-developing photo film unit comprising:

• said trap member comprising a strip-shaped chip and having first and second surfaces, said second surface being positioned on said mask sheet and having four side lines;
• one longer side line among said four side lines being near to an edge line of said mask sheet, being attached to said mask sheet with adhesive agent.

A self-developing photo film unit having a photosensitive sheet, a cover sheet, a mask sheet and a trap member, said photosensitive sheet being secured to said mask sheet to close an aperture in said mask sheet, said cover sheet being opposed to said photosensitive sheet, said mask sheet having first and second edge portions bent back to wrap edges of said photosensitive sheet and said mask sheet, and having edge lines secured to said cover sheet, said trap member being secured to said first edge portion, being positioned on said photosensitive sheet and/or said mask sheet, and trapping a surplus part of developing solution spread between said photosensitive sheet and said mask sheet, said self-developing photo film unit comprising:

• said self-developing photo film unit having a size of an ID-1 type card having an external size of a length varying from approximately 85.6 mm to 125 mm, a height of approximately 53.98 mm to 88.0 mm, and a thickness of approximately 0.76 mm, and a ratio of an area of said aperture to an area of a margin portion defined outside said aperture is 1.4 or more.