Apparatus for reading a film image with a photoelectric converting element and for adjusting the gain of said element

• US 4,974,068 A
• Filed: 02/10/1987
• Issued: 11/27/1990
• Est. Priority Date: 02/14/1986
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sato, Yuichi, Kobayashi, Takeshi, Yamada, Shigeki, Tsunekawa, Tokuichi, Hiramatsu, Akira, Katsuma, Makoto
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): VU, KIM Y
• Application Number:
  US07/013,119
• Time in Patent Office: 1,386 Days
• Field of Search: 358/43, 358/44, 358/54, 358/29, 358/29 C, 358/75, 358/214, 358/80
• US Class Current: 358/506
• CPC Class Codes: H04N 1/1008 with sub-scanning by translatory movement of the picture-bearing surface
• CPC Class Codes: H04N 1/4072 dependent on the contents of the original
• CPC Class Codes: H04N 1/484 with sequential colour illumination of the original
• CPC Class Codes: H04N 25/53 Control of the integration time
• CPC Class Codes: H04N 5/253 Picture signal generating by scanning motion picture films or slide opaques, e.g. for telecine scanning details therefor H04N3/36 ; standard conversion therefor H04N7/0112

Abstract

There is a film image information reading apparatus called a film scanner. This apparatus comprises: a lighting optical system to illuminate a film document; a photoelectric conversion element, such as a CCD to convert the image information of the film document into the electric signal; and an adjusting circuit to adjust the output of the photoelectrical conversion element such that a predetermined density of the film document is output as an output of almost the saturation level of that element. The predetermined density is the color density of the base color of a negative film. The adjusting circuit may control the charge storage period, gain, or output level of the photoelectric conversion element. With this apparatus, the positive image can be easily derived by reversing the negative image without considering the base color of the negative film and the image signal of a high quality can be obtained.

Claims

1. An apparatus for reading film image information, comprising:

a lighting optical system for illuminating a film document having color image information;

photoelectric conversion means for converting the color image information into a plurality of different output color electric signals;

detecting means for detecting, when a base of said film document is read, each level of the plurality of different output color electric signals output by said photoelectric conversion means; and

adjustment means for adjusting the plurality of different output color electric signals output by said photoelectric conversion means, wherein said adjustment means controls storage periods of said photoelectric conversions means for obtaining the plurality of different output color electric signals on the basis of each level of the plurality of different output color electric signals detected by said detecting means.

2. An apparatus according to claim 1, further comprising color separation means for color-separating the color image information.

3. An apparatus according to claim 1, wherein the base of said film document is an unexposed portion of said film document.

4. An apparatus according to claim 1, wherein said adjustment means determines each storage period of said photoelectric conversion means in such a manner that the level of each of said plurality of different output color electric signals attains a saturation level when the base of said film document is read.