Sheet-shaped film holding mechanism in projector

Claim 2

A sheet-shaped film holding mechanism in a projector comprising: a film carrier provided with a light transmission opening covered by a transparent plate and a guide channel in which said transparent plate is fitted and wherein a sheet-shaped film may be detachably inserted; a holding frame in which said film carrier is slidably fitted; and two rollers mounted springly on said holding frame so as to press a sheet-shaped film on said film caRrier into contact with said transparent plate, said rollers being mounted for rotation about axes extending at right angles to the direction in which said film carrier slides, said carrier having an elongated slot formed on its outside edge, said slot being closed at one of its ends, there being a projection on the film carrier extending into the inside of said long slot, said projection being disposed for engaging the closed end of said slot for preventing the carrier from slipping out of the holding frame, said carrier being provided with a sloped camming surface on the end thereof adjacent the closed end of the slot said surface being disposed relative to said closed end such that when the projection of the holding frame engages the closed end, the rollers on the holding frame are in a position out of contact with the transparent plate of said film carrier and overlying the sloping surface whereby upon pushing the film carrier toward its film holding position, said rollers are moved along said surface and are pressed into contact with said transparent plate of the film carrier.

Claim 3

A sheet-shaped film holding mechanism for a projector comprising: a film carrier having a light transmission opening and including a transparent plate disposed in covering relationship to said opening, said plate being of a size to underlie all frames of the pictures on a sheet-shaped film, said carrier having a channel disposed adjacent said transparent plate and extending therealong for substantially the entire length thereof, said channel being substantially the same width as the thickness of the sheet-shaped film and being provided at one end thereof with a notched inlet extending transversely of said channel and opening in a direction upwardly from the plane of said transparent plate for facilitating the insertion of a sheet-shaped film into the channel, said inlet having an arcuately shaped face disposed for guiding the sheet-shaped film into the channel, there being an end face at the opposite end of the channel from said inlet for restraining said sheet-shaped film against movement; a holding frame slidably mounting said film carrier for movement relative thereto in a direction along said channel; a pair of rollers rotatably mounted for rotation about axes extending generally perpendicularly of the sliding direction of said film carrier; and yieldable means mounting the rollers on said holding frame for biasing the rollers against the sheet-shaped film and thereby the latter into contact with said transparent plate, said rollers being spaced to present an area therebetween having a width slightly larger than one frame width on the sheet-shaped film, said film carrier being provided with an elongated slot extending parallel to the direction of said channel, said slot having an abutment at the end thereof remote from said inlet to the channel, said holding frame having a projection extending into said slot and being disposed for contacting the abutment to prevent movement of the film carrier out of the holding frame when the film carrier is moved in a direction toward the inlet of its channel, said carrier also being provided with a sloped camming surface adjacent the end of the transparent plate remote from said inlet, said surface being disposed for releasing the sheet-shaped film from the pressure exerted thereagainst by said rollers as the carrier is moved in said direction toward said inlet.

Claim 4

A sheet-shaped film holding mechanism for a projector comprising: a film carrier having a light transmission opening and including a transparent plate disposed in covering relationship to said opening, said plate being of a size to underlie all frames of the pictures on a sheet-shaped film, said carrier having a channel disposed adjacent said transparent plate and extending therealong for substantially the entire length thereof, said channel being substantially the same width as the thickness of the sheet-shaped film and being provided at one end thereof with a notched inlet extending transversely of said channel and opening in a direction upwardly from the plane of said transparent plate for facilitating the insertion of a sheet-shaped film into the channel, said inlet having an arcuately shaped face disposed for guiding the sheet-shaped film into the channel, there being an end face at the opposite end of the channel from said inlet for restraining said sheet-shaped film against movement; a holding frame slidably mounting said film carrier for movement relative thereto in a direction along said channel; a pair of rollers rotatably mounted for rotation about axes extending generally perpendicularly of the sliding direction of said film carrier; and yieldable means mounting the rollers on said holding frame for biasing the rollers against the sheet-shaped film and thereby the latter into contact with said transparent plate, said rollers being spaced to present an area therebetween having a width slightly larger than one frame width on the sheet-shaped film, said film carrier being provided with an elongated slot extending parallel to the direction of said channel, said slot having an abutment at the end thereof remote from said inlet to the channel, said holding frame having a projection extending into said slot and being disposed for contacting the abutment to prevent movement of the film carrier out of the holding frame when the film carrier is moved in a direction toward the inlet of its channel, said carrier also being provided with a sloped camming surface adjacent the end of the transparent plate remote from said inlet, said surface being disposed for releasing the sheet-shaped film from the pressure exerted thereagainst by said rollers as the carrier is moved in said direction toward said inlet.