Photographic film type sensor
US4341453A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 7, 1981 |
| Grant date | Jul 27, 1982 |
| Priority date | — |
| Expiry date | May 7, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03D3/065
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An automatic replenisher control system for a photographic cine processor includes a film type sensor which identifies, by film type, the unprocessed film entering the processor. Replenishment of processor fluids is controlled as a function of the identified film type. The film type sensor includes an array of reflective infrared (IR) sensors which are positioned across a path of the film. Each infrared sensor provides a sensor signal indicative of whether the film is adjacent the infrared sensor. Signal processing circuitry, including a digital computer, first determines the width of the film by sampling the signals from the infrared sensors a series of times, and totalling the number of sensor signals indicating the film is adjacent the sensor. 110 format film and large format films (such as 46 mm, 120/220 and 70 mm format films), are identified solely on the basis of width. A perforation sensing routine is performed to distinguish between leader, 126 format film and 135 format film. The perforation sensing is performed by reading the output signals of selected IR sensors and determining the presence of perforations along each edge of the film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.