Patent · US Expired

Method of detecting image frame and apparatus thereof, method of positioning image frame, photographic film carrier, and method of printing photographic film

US5260740A · kind A · utility

21Cited by
3References
20Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 27, 1992
Grant dateNov 9, 1993
Priority date
Expiry dateMay 27, 2012

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03B27/6285
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

An image frame detecting apparatus of the present invention is provided with a light emitting portion provided in one of the respective sides of a guide path for a carrying photographic film, and including a light emitting diode (LED) array having a plurality of LEDs disposed in the transverse direction of the photographic film, a light receiving portion provided in the other of the respective sides of the guide path for the photographic film, and receiving light emitted from the light emitting portion, and a detecting portion for detecting an image frame recorded on the photographic film depending upon the quantity of light received by the light receiving portion. The LEDs has a reduced fluctuation and a reduced range of temperature change so that transmission density of the photographic film can be accurately detected. An image frame and a base portion of the photographic film can be surely discriminated. Further, the extended life of the LED allows to reduce a regular exchanging operation required when a cold-cathode tube or a halogen lamp or the like is used for a light source, and to improve a maintenance efficiency.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.