Lens-fitted film unit

Details Lens-fitted film unit Lens-fitted film unit

1999-05-18

2002-02-26

Adams, Russell (Department: 2851)

Photography

Disposable or recyclable camera

C396S155000

Reexamination Certificate

active

06351604

ABSTRACT:

BACKGROUND OF THE INVENTION
The present invention relates to a lens-fitted film unit in which a silver halide color photographic light-sensitive material is loaded, an image outputting method and a print, and more particularly, to a lens-fitted film unit, an image outputting method and a print which make it possible to obtain a high quality color print with less failure even when photographing under the conditions of under exposure and over exposure.
What is called a lens-fitted film unit which is sold in a condition that a silver halide light-sensitive material (hereinafter referred to as a light-sensitive material, or a film) is loaded in a plastic camera equipped with a simple and fixed focus lens, has spread recently. This lens-fitted film unit has eliminated the trouble of loading a film in an ordinary camera and eliminated the failure caused by erroneous loading, and increased photographing chances with its simple and convenient nature.
A lens-fitted film unit is a photographing unit in which a light-sensitive material is loaded in advance by a maker as is widely known, and it is used by a user only for photographing on one roll of the loaded light-sensitive material, and after completion of photographing, the lens-fitted film unit is sent to a photofinisher together with a light-sensitive material housed in the lens-fitted film. Therefore, the camera is made to be extremely simple in terms of structure and to be inexpensive in terms of price.
Accordingly, a driving system, an optical system and an electric system of the lens-fitted film unit are extremely simplified because of the targeted low cost of the lens-fitted film unit, which is different from an ordinary camera. Therefore, there are many problems of unsatisfactory finish of processing and unsatisfactory print quality which are desired to be improved.
For example, a camera is designed so that a close-range view through a distant view may be focused even with a fixed focus lens, by making an aperture value to be great, and a film having ISO speed of 320 or more is generally used because sensitivity is insufficient. TOKKAIHEI No. 8-129249 discloses a technology wherein a film with ISO speed of 640 or more is loaded in a lens-fitted film unit whose lens having an Ev value of 13.4-13.9 for decreasing the number of under exposure prints. However, improvement of print quality under the condition of such a high speed film has not been sufficient for users.
When an electronic flash unit is built in a lens-fitted film unit, indoor photographing or photographing at night is possible, and TOKKAIHEI No. 5-188454, for example, discloses a technology wherein print quality is improved by reducing frequency of under exposure in electronic flash photographing by making a guide number (GN) to be 10-15 on a lens-fitted film unit whose lens having an Ev value of 11-13.5. In this technology, however, there still has been a problem that a difference between a highlight and a shadow in background which is out of the radius of electronic flash light is large and unnatural because the distance covered by an electronic flash unit is short, and it is hard to obtain satisfactory prints.
Incidentally, a focal length of the lens of the lens-fitted film unit described in the aforesaid official gazette is about 30 mm, and a film frame size to be exposed is 24×36 mm. By making the focal length to be shorter than the foregoing and by making the film frame size to be exposed to be smaller than the foregoing in terms of area, it is possible to increase an amount of exposure per unit area to be greater than the amount of exposure per unit area in the aforesaid specification. For example, specifications of the disk film camera made by Kodak Co. (Type: Disk 4000) are as follows.
Focal length: 12.5 mm, F value: 2.8, Shutter speed: {fraction (1/200)}, Ev value: 1.5, Film frame size: 8.2×10.6 mm
In the case of this disk film camera, low speed films with ISO speed of about 200 are the only films available, and a speed of a film to be loaded in the camera has been determined by a user based on the condition of photographing. Namely, a film having an optimum ISO speed is loaded in a disk film in advance, and there has been no design concept to determine optimum camera specifications on the assumption of the optimum ISO speed. Therefore, there has been no concept to materialize a camera housing with no electronic flash unit by incorporating a high speed film in advance, or to make a camera smaller or thinner by using no built-in electronic flash unit. In the case of a disk film camera, there has been a case where an electronic flash unit is caused to flash in photographing even under the photographing condition in which the film speed does not need electronic flash, resulting in over exposure.
SUMMARY OF THE INVENTION
An object of the invention is to provide a lens-fitted film unit which reduces the frequency of under exposure and over exposure, and makes it possible to obtain photographic prints which are highly satisfactory even when the camera is a simplified one. The present invention also relates to an image outputting method and photographic prints.
The object stated above can be attained by the following structures.
(1) A lens-fitted film unit having therein an unexposed film which is loaded in advance and has ISO speed of Sviso, a lens having a fixed focal length of f (mm) and a fixed aperture value of F, and a shutter having a fixed shutter speed T (sec), wherein system sensitivity index S is 0-4.5, and following conditions are satisfied.
System sensitivity index S=EV value Ev−Film speed index Sv
Film speed index Sv=3.32 log
10
(0.3×Sviso)
EV value=3.32 log
10
(F
2
/T)
(2) In the lens-fitted film unit, there is provided a body having the maximum thickness of 7 mm-23 mm.
(3) In the lens-fitted film unit, the unexposed film is a sheet film having a film frame size in which a short side is 7 mm to 14 mm and a long side is 10 mm to 20 mm.
(4) In the lens-fitted film unit, the EV value is 6.5 to 11.
(5) In the lens-fitted film unit, an electronic flash unit having G No. of 10 or less is provided.
(6) In the lens-fitted film unit, the fixed focal length is 5 mm to 20 mm.
The object of the invention stated above can further be attained also by the following preferable structures.
(7) A lens-fitted film unit in which an unexposed film is loaded in advance to be ready for photographing, wherein Ev value of the lens-fitted film unit is 6.5 to 11.
(8) The lens-fitted film unit described in the structure (7), wherein a shutter speed constituting the Ev value is {fraction (1/150)} sec. to {fraction (1/25)} sec.
(9) The lens-fitted film unit described in the structure (7) or (8), wherein an aperture value (F-number) constituting the Ev value is 2 to 8.5.
(10) A lens-fitted film unit in which an unexposed film is loaded in advance to be ready for photographing, and a speed of the loaded unexposed film is adjusted so that the system sensitivity index (S) may be 0 to 4.5, wherein the following is satisfied,
System sensitivity index S=Ev−Sv
Sv is a film speed index and is represented by the formula:Sv=3.32log
10
(0.3×ISO speed)
(11) The lens-fitted film unit described in the structure (10), wherein latitude L of the loaded unexposed film satisfies the following expression (1).
4.3≦L+0.3S≦4.9  (1)
(12) The lens-fitted film unit described in the structure (11), wherein latitude L and gamma value &ggr; of the loaded unexposed film satisfy the following expression (2).
1.0≦L×&ggr;≦2.0  (2)
(13) The lens-fitted film unit described in the structure (11) or (12), wherein latitude L and/or gamma value described in the structure (11) or (12) is satisfied by changing developing conditions for the film.
(14) The lens-fitted film unit described in either one of the structures (7) to (13), wherein no electronic flash unit is housed in the lens-fitted film unit, or an electronic flash unit having its guide number of less than 10 is housed.
(15) The lens-fitted fil

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