There are often scenes and informations incidentally encountered in daily life which are desirable to be photographed, but the person who wishes to take photographs is not necessarily carrying always a picture-taking camera. In view of such incidental photographing chances which may often occur, there has been a strong potential demand for a picture-taking system suitable therefor.
For such a demand, a so-called lens-combined film system has been developed and is now familiar to many people. One of the important materials for the above system is a high sensitivity color negative light-sensitive material. In order to cover photographing of an object in a near distance to a far distance with a low cost fixed-focus plastic lens, a relatively dim lens having large depth of field is required and, for compensating this, a high sensitivity color negative light-sensitive material is used. For this reason, a light-sensitive material of about ISO 400 is used in the lens-combined film. Also, recently, a super high sensitivity film of ISO 800 which is conventionally belongs to a supper high sensitivity region is used for a lens-combined film and is accepted by the consumer with a good reputation.
On the other hand, another demand for photographing is that the person who takes photographs wants to instantaneously see the photographs taken. For this demand, color films for a so-called instant camera are commercially available, but such films are not widely accepted due to their high prices and unsatisfactory image quality of photographs.
For the above demand, efforts have continuously been made in the field of development processings of the color negative light-sensitive materials. The time for development processing of the color negative light-sensitive material has speeded-up by the C-41 processing introduced by Eastman Kodak in 1972 in which the wet processing time excluding a drying step is shortened up to 17 minutes and 20 seconds. Further, in the rapid processing CN-16FA which has recently been introduced by Fuji Photo Film Co., Ltd. for mini-laboratory markets, the processing time is shortened up to 8 minutes and 15 seconds. Also, the processing time of color print light-sensitive materials has markedly speeded-up by the RA-4 processing introduced by Eastman Kodak in 1986 in which the processing time including a drying step is shortened to a level of 4 minutes.
However, at present, when users ask a photo shop to print the photographed negative, it takes 20 to 30 minutes even by the processing at the most rapid-finishing shop (i.e., mini-laboratory) to make prints, and, thus, most of the customers are required to visit the photo shop twice. In order to satisfy the users needs in the color negative and color paper system applied at present so as to get the prints by visiting the photo shop once, it is necessary to greatly shorten the time required for the development processing.
However, it is very difficult to achieve the above purpose without considering the shortening of time including the color development step. Taking, for instance, a development processing of the color negative, the conventional speeding-up has mainly been achieved by shortening the time for a desilverization step, and, in the case of the processing of the above-described CN-16FA, the time required for the color development takes 40% or more of the total processing time.
As a technique for shortening the time for color development, a method for forming a color image of a color negative silver halide photographic material in which an average silver chloride content is 5 mol % or more and each of gamma R, gamma G and gamma B in the red-sensitive layer, the green-sensitive layer and blue-sensitive layer after color development is in the range of from 0.4 to 1.0, respectively, is disclosed, for example, in JP-A-3-149546 (the term "JP-A" as used herein means and "unexamined published Japanese patent application"). According to the above method, the time for the color development can be certainly shortened from 3 minutes and 15 minutes which is presently required to 1 minute and 30 seconds. However, in the above photographic material, a silver chlorobromide emulsion is used since the speeding-up is an important factor, and, therefore, the sensitivity of the photographic material is estimated as about 100 at most in terms of the ISO photosensitivity. Thus, advantages of high sensitivity and excellent graininess obtainable by using an iodobromide emulsion is sacrificed in the above photographic material. In addition to the above-described method, some methods for shortening the time for color development have been proposed, for example, in JP-A-4-93836, JP-A-4-234758, JP-A-4-234759, JP-A-4-356044 and JP-A-5-197095, but each of the proposed method uses a silver chlorobromide emulsion.
On the other hand, considering the present circumstances in which the C-41 processing of Eastman Kodak and the development processing having an interchangeability thereto have been popular worldwide, it may be very difficult to introduce any changes of the color development step including the time into the actual markets. More specifically, during an initial period of time in which a rapid processing machine is not popular in markets, introduction of a color negative photographic material which can be normally finished only with the rapid processing may be advantageous in only a very limited market.
In the present color photography, a system of taking photographs with a color negative and printing on color papers is widely accepted. The reasons therefor are that the color negative film has a very broad exposure latitude and, hence, chances of failure in photographing are very low. Differing from color reversal films and color papers, the color negative film is a photographic material which is desired in such a manner that the gradation can be reproduced in a broader exposure region. When the gradation and the gradation balance in each of the light-sensitive layers are poor, a tone reproducibility and a color reproducibility are deteriorated thereby adversely affecting the color tone upon printing.
Accordingly, it is very important to develop a technique for controlling the gradation and the gradation balance in order to obtain excellent finished quality even in either the development processing which is now broadly accepted worldwide, or the development processing for a period of time which differs from the most popular color development time.
As set forth above, a system which makes it possible to take photographs at the time as required and to obtain prints immediately after taking the photographs has not been put into a practical use, and at present the technical development for these purposes is strongly desired.
USPTO Backgrounds
USPTO Backgrounds