METHOD OF DETECTING IMAGE FRAME AND APPARATUS THEREOF, METHOD OF POSITIONING IMAGE FRAME, PHOTOGRAPHIC FILM CARRIER, AND METHOD OF PRINTING PHOTOGRAPHIC FILM

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.