Photographic Printing Device

This invention is concerned with a device for producing photographic prints from transparencies such as slides, preferably employing an instant film pack as the printing medium.

In the past, a number of devices have been described for producing photographic productions or prints from black and white negatives and slides. For example, in my prior Swiss Pat. No. 598,614, patented Nov. 15, 1978, a slide printer is provided comprising a housing having a front panel and a rectangular opening at the raised section forward of the panel. A ground glass covers the opening and thereover is fitted an instant film pack. A dark compartment is located in the housing beneath the glass containing an angled mirror and a lens. Knobs external to the housing for adjusting lens aperture and telescoping are linked to the lens. Another compartment is located beneath the panel which houses a light source at one side bounded by two reflecting mirrors. A third mirror is located to the side of the light source and is angled to reflect light toward the lens. Between the angled mirror and the lens is, in order, a diffuser, a filter and a slide, each removably retained in holders.

One disadvantage of the device of my prior Swiss patent was that the light source used therein comprised a quartz light which did not match the Kelvin rating of the instant film contained in the film pack. Such films, as currently manufactured have a daylight Kelvin rating of about 5400 Kelvin. Quartz lights, have a Kelvin rating of about 3400 Kelvins so it is necessary to use filters in such device to increase the Kelvin rating to match the rating of the film. Moreover, quartz lights develop significant amounts of heat, need to be exposed for longer periods of time to produce a satisfactory print and often cause buckling of the transparency.

In U.S. Pat. No. 3,065,667 to H. E. Edgerton an apparatus for making enlarged prints from transparencies or slides is described. The apparatus comprises a light-tight housing having at the top a processing head which can be a self-developing "Polaroid" camera with its film portion facing inwardly of the housing. The slide is placed in a holder beneath which is a light source such as a flash unit. A lens whose aperture may be controlled by a diaphragm is located between the slide and film and focuses an enlarged image on the film. Other printing devices have been described in the art which employ a camera as the medium for production of the photographic image. Such devices have been described in U.S. Pat. Nos. 4,076,413; 3,689,148; 3,454,943; 3,697,175 and 3,653,760.

The present invention is an improvement over my prior Swiss patent and is characterized by a more efficient and simpler design, that is, it does not contain a plurality of light reflecting mirrors or lens telescoping means. Moreover, the present invention employs the use of a flash unit having a Kelvin rating which matches the daylight rating of the instant film. In order to break up the contrast of the print an opalescent glass or opalescent plexiglass plate is employed between the flash unit and the instant film pack. Without such plate the contrast of the print would be too high. The plate acts to produce a soft print on the instant film.

The present invention provides a device for producing photographic prints on a printing medium from a transparency such as a slide or negative. The device preferably employs the use of an instant developing film pack as the printing medium but can also employ other paper printing media for producing both colored or black and white prints.

The device comprises a housing having a bottom, a forward section, an intermediate section and a rear section. A holder for an instant film pack is located in the rear section comprising a flat face on which the film pack rests having a rectangular aperture which registers with the printing paper or material of the pack and defines the size of the image. The aperture is covered by a ground glass plate. Means for retaining the film pack are mounted on the holder comprising L-shaped members extending upwardly from the face defining guide channels through which the side edges of the pack are inserted. Spring means are provided in the channels to retain the pack in place in the holder. The lower portion of the holder comprises a walled, boxlike section comprised of or coated with a light absorbtive material which extends into the rear section to form a light-tight compartment. A reflecting mirror is mounted in this compartment at an angle of about 45.degree. with respect to the bottom. Extending from the front to the intermediate sections of the housing is a longitudinal housing defining an image forming chamber. The image forming chamber contains a source of illumination such as a flash tube, an opalescent glass plate or opalescent plexiglass plate located rearward of the tube, and a slide and filter chamber located rearward of the opalescent plate for insertion of a slide transparency and filter. A lens assembly extends from the rearward end of the image forming chamber into the light-tight compartment through an opening in the holder wall. The lens assembly preferably comprises a 50 mm lens and an aperture adjustment annulus to enable sharpening of the image to the film pack. The annulus is connected by linking means to a knob in the housing's intermediate section for remote lens adjustment.

The device is electrically operated by means of 110 or 220 V or battery. A pulse generator is connected with the power source and flash tube and is activated by a flash button located on the housing front section. A timer may also be present to time the exposure of the flash.

FIGS. 1 & 2 show a side view and top view, respectively, of the printer of this invention.

FIG. 3 is a perspective view of the printer of FIGS. 1 & 2 having an instant film pack mounted thereon.

FIG. 4 shows a front view of a holder useful in the printer for holding a slide or filter.

FIGS. 1 & 2 show a side view and top view, respectively, of the slide printer of this invention which is useful for producing colored or black and white prints on a printing medium from photographic transparencies such as slides. The printer is particularly useful for printing colored slides by employing a self-developing or instant film pack associated with the printer. The printer may also be used to produce black and white prints on conventional photographic printing paper from black and white negatives. It may also be used to produce black and white negatives.

The printer comprises a hollow housing 11 having the configuration shown consisting of a base section 12, forward section 13, upwardly extending intermediate section 14 and rear section 15. Mounted atop the rear section 15 is holder 16 which retains an instant color film pack such as those manufactured and sold by the Polaroid Corporation or the Eastman Kodak Company. Such film packs having heretofore been used in self developing cameras for instantly producing colored prints as well as known in the art. Such films generally have a daylight rating of about 5400 Kelvin. The bottom of the holder 16 comprises a box-like section bounded by walls 17 made of or coated with a light absorbing material which extends into the rear section 15 of the housing 11 to form a light-tight compartment 18. The face 19 of the holder comprises a flat metal plate having rectangular opening 20 which meets the formatt of the instant developing film pack. A section of glass 21 overlies the opening. Extending above the face 19 of the holder on opposite sides thereof are a pair of L-shaped members 23 which form guide channels 24 into which the ends of the film pack are inserted. A pair of leaf springs 25 are fastened to the L-shaped members at each end to retain the film pack in the holder after insertion. FIG. 3 shows a film pack 26 set in place in the holder. Extending from the forward to the intermediate sections of the housing is a longitudinal housing 27a defining image forming chamber 27. Mounted at the forward end of this chamber is a source of illumination such as a flash tube 28 held in bracket 29. It is preferred that this tube be mounted horizontally in the chamber as shown to provide even illumination across the transparency. The tube 28 is connected by appropriate wiring to a pulse generating circuit board 29 which is supplied by external voltage through power lines 30. The source of power for the printer may be conventional 110 or 220 V AC using socket connector 31 or a battery (not shown). On-Off button 32 is used to switch power on and off to the circuitry and flash button 33 is used to initiate an electronic pulse to the flash tube from the pulse generator circuit. The design of such circuitry is well known in the art and will not be described herein. Forward of the flash tube is an opalescent glass plate 34 whose purpose is to break down the contrast of the image projected on the film pack as previously mentioned. A filter and slide holder assembly 35 is located ahead of the opalescent plate 34 which comprises a filter chamber 36 and slide chamber 37 extending vertically from the bottom section 12 through the face of section 13 to permit access to each chamber through the top of section 13. The chambers are bounded on two opposing sides by a pair of longitudinal E-shaped members 38. Filter holder 39 and slide holder 40 fit within chamber 36 and 37 along the channels formed by the E-shaped member. A pair of leaf springs 41 are located against the forward inner wall of the E-shaped members to retain the slide and filters in their respective channels. A tab 42 in each holder allows the user of the device to remove and insert each holder from the forward section.

FIG. 4 is a front view of a slide holder 40 which is identical to filter holder 39. The holder has a rectangular opening equal to the size of the image on the slide. An upper ledge 44 and lower ledge 45 are formed in the holder above and below the opening 43 between which is nested the cardboard mounting of a slide or other transparency.

Mounted at the forward end of chamber 27 is a 50 mm lens assembly 46 having aperture adjustment annulus 47. A light-tight lens cover 48 fits over the lens assembly and extends into light-tight compartment 18 through an aperture in wall 17 of housing 16.

A lens aperture adjustment knob 49 is located on the face of the intermediate section 14. An extension 50 of the knob 49 protrudes into section 14 having an apertured pin 51 fastened thereto at a right angle to the knob. One end of a linking wire 52 is connected to pin 51 at its aperture and the other end is connected to apertured pin 52 mounted on bracket 54 which in turn fastened to annulus 47 by bracket 54 by means of a screw fastener. Movement of the knob 49 in a clockwise or counterclockwise direction will, by means of the linking wire, affect a corresonding movement of the lens annulus 47 so that external lens aperture adjustment can be precisely adjusted to control the quality of the print.

A reflecting mirror 55 is fastened to the bottom section of the housing by means of brackets 56 and screw fasteners 57. The mirror is set at an angle of about 45.degree. from the horizontal and acts to project the image from the lens onto the film pack nested in the holder.

Operation of the printer of this invention is as follows. The instant film pack 26 is first inserted into the holder 16 as shown in FIG. 3. Power is turned on by pushing the On-Off button 32. The lens aperture adjustment knob 49 is then set, usually to f/11 for normally exposed slides. After inserting a slide in its holder it is placed in the slide chamber 37. To expose the instant film in the pack a safety cover on the right side of the film pack and a flexible slide on the left side of the film pack are removed. The flash button is depressed to make the exposure and thereafter the white tab 25a on the film pack is pulled outwardly exposing a yellow tab (not shown). The yellow tab is pulled out and the exposure timed for development. For this purpose an electric timer may also be associated with the machine. After timing a print is separated from the negative as per the instructions on the film pack.

Alternatively, a black and white negative may be inserted in the slide holder instead of a slide and conventional photographic print paper may be substituted for the film pack to produce a standard black and white print.

It should further be emphasized that, unlike the device of my prior Swiss patent which used a quartz lamp, the present invention provides a flash unit which matches the daylight Kelvin requirements of the instant film, i.e. about 5400.degree. K. In order to break down the undesirable high contrast of the print after exposure which would normally result, the opalescent glass or plexiglass plate is employed which produces a softer print having even tone color saturation. Filters are used with the slide in this invention not to increase the Kelvin rating of the slide as must be done according to the device of my prior Swiss patent, but to allow the operator to merely alter the colors or hues on the slide to be printed. Without filterization, the present device prints exactly what is present in the slide.