# US 4,395,793 A · Photographic film cleaner > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,395,793 A - Document ID: US4395793A - Status: Granted - Kind: A - Application number: 06/349,930 - Filed: 1982-02-18 - Granted: 1983-08-02 - Earliest claimed: 1982-02-18 - Assignees: Pako Corporation - Inventors: John A. Wedel; Robert L. Skubic - Web page: https://patentgrep.com/patent/US4395793A ## CPC - G03D 15/00: Apparatus for treating processed material - G03B 27/462: {in enlargers, e.g. roll film printers} - G03G 21/0052: {using an air flow; Details thereof, e.g. nozzle structure} - G03D: APPARATUS FOR PROCESSING EXPOSED PHOTOGRAPHIC MATERIALS (apparatus specially adapted for photomechanical production of textured or patterned surfaces G03F); ACCESSORIES THEREFOR (photosensitive materials or processes for photographic purposes G03C; electrographic, electrophotographic, or magnetographic methods or apparatus G03G) - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A film cleaning apparatus cleans photographic film while the film is clamped at the print gate aperture of a photographic printer. When the film is clamped at the print gate, and before a print exposure is initiated, high velocity ionized air is directed onto both the top and bottom surfaces of the film to remove dust and other foreign materials from the film surfaces. When the exposure is commenced, the flow of ionized air is reduced to a low velocity which is sufficient to prevent dust from settling on the film surfaces during exposure. ## Claims ### Claim 1 Photographic film cleaning apparatus for cleaning an image area of photographic film at a print gate aperture of a photographic printer, the apparatus comprising: clamping means at the print gate for clamping the photographic film with the image area aligned with the print gate aperture prior and during an exposure cycle of the printer; means for directing a first higher velocity gas onto the image area of the clamped photographic film prior to the exposure cycle to remove particles from a surface of the image area; and means for directing a second lower velocity gas onto the image area of the clamped photographic film during the exposure cycle to prevent particles from settling on the surface of the image area. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein the means for directing a first higher velocity gas and the means for directing a second lower velocity gas comprise: first nozzle means for directing a stream of gas at an acute angle onto a first surface of the image area of the clamped photographic film; and means for selectively providing a first higher pressure gas to the first nozzle means to produce the first higher velocity gas in a stream from the first nozzle means prior to the exposure cycle and selectively providing a second lower pressure gas to the first nozzle means to produce the second lower velocity gas in the stream during the exposure cycle. ### Claim 3 (depends on 2) The apparatus of claim 2 wherein the clamping means has a first ramp surface extending from a position proximate the first nozzle means to a position proximate the print gate aperture to guide the gas stream from the first nozzle means to the first surface of the photographic film. ### Claim 4 (depends on 3) The apparatus of claim 3 wherein the clamping means includes means for guiding the gas stream away from the print gate aperture after it has passed over the first surface of the clamped photographic film. ### Claim 5 (depends on 4) The apparatus of claim 4 wherein the means for guiding the gas stream comprises a second ramp surface positioned on an opposite side of the print gate aperture from the first ramp surface and sloped away from the image area to guide the gas stream away from the first surface of the clamped photographic film. ### Claim 6 (depends on 5) The apparatus of claim 5 wherein the means for guiding further includes a gas passage having an inlet communicating with the second ramp surface for receiving the gas stream and directing the gas stream away from the print gate. ### Claim 7 Photographic film cleaning apparatus for cleaning an image area of photographic film at a print gate aperture of a photographic printer, the apparatus comprising: clamping means at the print gate for clamping the photographic film with the image area aligned with the print gate aperture; first nozzle means for directing a first gas stream at an acute angle onto a first surface of the clamped image area of the photographic film; second nozzle means for directing a second gas stream at an acute angle onto a second surface of the clamped image area of the photographic film; and gas supply means for supplying gas to the first and second nozzle means. ### Claim 8 (depends on 7) The apparatus of claim 7 wherein the gas supply means comprises: means for supplying first high pressure gas to the first and second nozzle means prior to an exposure cycle of the printer to remove dust from the first and second surfaces of the clamped image area; and means for supplying a second lower pressure gas to the first and second nozzle means during the exposure cycle to prevent dust from settling on the first and second surfaces of the image area during exposure. ### Claim 9 (depends on 7, 8) The apparatus of claims 7 or 8 wherein the gas supply means comprises: an inlet for receiving air under pressure; a high pressure path between the inlet and the first and second nozzle means; a high pressure solenoid valve connected in the high pressure line for controlling air flow through the high pressure line to the first and second nozzle means; a low pressure line connected between the inlet and the first and second nozzle means; a low pressure solenoid valve for controlling air flow through the low pressure line to the first and second nozzle means; and control means for controlling the high pressure solenoid valve and the low pressure solenoid valve. ### Claim 10 (depends on 9) The apparatus of claim 9 and further comprising: ionizing means connected between the high and low pressure lines and the first and second nozzle means for ionizing air supplied from the high and low pressure lines to the first and second nozzle means. ### Claim 11 (depends on 7) The apparatus of claim 7 wherein the clamping means comprises: a movable aperture plate at the print gate having a first aperture; a stationary aperture plate at the print gate having a second aperture; means for selectively moving a movable aperture plate between a clamping position in which an image frame of the photographic film is clamped at the print gate aperture between the movable and stationary aperture plates with the image plane aligned with the first and second apertures, and a non-clamping position in which the movable aperture plate is spaced from the photographic film and the stationary aperture plate to permit indexing a selected image area of the photographic film into alignment with the print gate aperture. ### Claim 12 (depends on 11) The apparatus of claim 11 wherein the movable aperture plate has a ramp surface extending from a position proximate the first nozzle means to the first aperture for guiding the gas stream from the first nozzle means to the first surface of the clamped image area. ### Claim 13 (depends on 12) The apparatus of claim 12 wherein the movable aperture plate further includes means for guiding the gas stream away from the print gate aperture after it has passed over the first surface of the clamped image area. ### Claim 14 (depends on 13) The apparatus of claim 13 wherein the means for guiding includes a passage extending through the movable aperture plate. ### Claim 15 (depends on 11, 12) The apparatus of claims 11 or 12 wherein the stationary aperture plate has a ramp surface extending from a position proximate the second nozzle means to the second aperture for guiding the gas stream from the second nozzle means to the second surface of the clamped image area. ### Claim 16 (depends on 15) The apparatus of claim 15 wherein the stationary aperture plate further includes means for guiding the gas aperture after it has passed over the second surface of the clamped image area. ### Claim 17 (depends on 16) The apparatus of claim 16 wherein the means for guiding includes a passage extending through the stationary aperture plate.