US3694079A

US3694079A - Photographic printing apparatus and method for reproducing an original having separate major areas of respectively different densities

Info

Publication number: US3694079A
Application number: US864419A
Authority: US
Inventors: James Edward Harvey
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-10-07
Filing date: 1969-10-07
Publication date: 1972-09-26
Anticipated expiration: 1989-09-26
Also published as: GB1330676A; JPS5017251B1; FR2064911A5; CA931002A; DE2049328A1

Abstract

An apparatus and method for producing, by a single exposure a print of a film transparency having separate major areas of respectively different densities. The exposure of a lower density area is variably reduced or dodged with respect to an adjacent or surrounding high density area through the use of polarizer filters. The apparatus is particularly suited for printing identification card film negatives having a portrait area of low density and a data area of high density.

Description

1 1 Sept. 26, 1972 United States Patent Harvey S 6/1961 Craig......................

1541 PHOTOGRAPHIC PRINTING 2,988,978 .355/20 X APPARATUS AND METHOD FOR 3,183,766 5/1965 Takasaka.....................355/20 REPRODUCING AN ORIGINAL HAVING SEPARATE MAJOR AREAS Primary Examiner-John M. l-loran OF RESPECTIVELY DIFFERENT Attorney-Robert W. Hampton and John D. l-lusser DENSITIES [5 7] ABSTRACT An apparatus and method for producing, by a single exposure a print of a film transparency having separate major areas of respectively different densities. The exposure of a lower density area is variably reduced or dodged with respect to an adjacent or sur- [72] inventor: James Edward Harvey, 901 Elm- 221 Filed:

rounding high density area through the use of polarizer filters. The apparatus is particularly suited for printing identification card film negatives having a 5 u 31 L N 709 y m; 5 ml 7 H m e1 3 "a... W h c r 8 "e "Us .L C

UIF 1:11 2 8 555 [.11.

portrait area of low density and a data area of high density.

[56] References Cited UNITED STATES PATENTS 9 Claims, 2 Drawing Figures 2,186,619 1/1940 Sauer...........................355/7l PATENTED8 2 9 2 3.694.079

sum 2 or 2 JAMES E. HARVEY INVENTOR.

BY M $21 M ATTORNEYS PIIOTOGRAPIIIC PRINTING APPARATUS AND METHOD FOR REPRODUCING AN ORIGINAL HAVING SEPARATE MAJOR AREAS OF RESPECTIVELY DIFFERENT DENSITIES BACKGROUND OF THE INVENTION The invention relates to apparatus and methods for producing a print from a film transparency having separate major areas of respectively different densities with a single exposure.

As is well known, the use of photographic identification cards has become widespread in recent years. Such cards first appeared as security passes when the need for security measures became generally recognized in the military and in industry. More recently, photographic identification cards have come into wide use as credit cards.

The preparation of photographic identification cards, that is, the printing of the cards from the film negative, has presented a major problem, particularly when color film is used. The problem arises from the fact that such film negatives comprise in some instances at least two separate major areas of respectively different densities, for example, a portrait area of low density and a data area of high density. The difficulty of printing such a film negative with a single exposure in the printer is apparent; however, for economic and other reasons, single exposure printing is of course desirable.

Probably the most well known method of printing the above type of film negative is the one in which hand dodging with a mask is employed. This method requires a printer operator skilled in dodging techniques and is a time consuming operation not suited for mass production. Many other methods have been proposed for printing from a film negative having separate major areas of respectively different densities, but these have proven unsatisfactory for one reason or another.

SUMMARY OF THE INVENTION Accordingly, it is an object of the invention to provide improved apparatus for producing on a medium a reproduction of an original having separate major areas of respectively different optical densities with a single exposure.

Another object of the invention is to selectively at tenuate, through the use of polarizing mediums, the amount of light transmitted to different areas of a recording medium.

A further object of the invention is to provide a method for producing, by asingle exposure, a print of uniform density from a film negative having separate major areas of respectively different densities.

Still another object of the invention is to produce, through the use of polarizing filters, a photographic print of uniform density from a film negative having separate major areas of respectively different densities.

In the disclosed embodiments, light is transmitted through an original having at least two separate major areas of respectively different densities; such as a film negative and at least two polarizing mediums to a photosensitive medium. One of the polarizer mediums is moved with respect to the other in order to attenuate the amount of light transmitted through both polarizer mediums and the lower density area of the film negative so as to vary the exposure of at least that corresponding portion of the photosensitive medium.

Other objects and advantages of the invention will become apparent in the detailed. description of the preferred embodiment presented below.

BRIEF DESCRIPTION OF THE DRAWings DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1 of the drawings, an apparatus is shown for producing, by projection printing, a photographic print on a photosensitive medium 10 from a film 12 containing a film negative 14 having separate major areas of differing densities. Film 12 is supported by a film gate, here illustrated as a surface 16 with film guides 18 and having a projection aperture 20. The apparatus includes a light source 22 and a condenser lens system 24 for directing light through projection aperture 20 of surface 16 and through negative 14. An image of the negative image borne by negative 14 is formed on medium 10 by a printing lens 26 which is suitably supported in the projection light path of light source 22. Photosensitive medium 10 is suitably supported in a print exposure station, here defined by guide members 28.

In this instance, the film negative 14 is illustrated as comprising a negative of a photographic identification card having a portrait or first major area 30 which is an area of relatively low density, and a data or second major area 32, which is an area of relatively high density. The density of the data areas of different identification card negatives will not vary materially but rather will be substantially the'same. On the other hand, the density of the portrait areas of such negatives will vary from one roll of negative film to the next when each has been exposed by different photographers using different lighting techniques and equipment. Indeed, the density of the portrait areas of such negatives will vary from negative to negative on the same roll of film since the complexions of the various subjects will differ. Therefore, the exposure differential will also vary from film roll to film roll, and even from negative to negative on the same film roll. It is therefore desirable that the exposure differential be capable of ready equalization.

A polarizing means comprising a sheet of polarizer material 34 is positioned to cover only the portrait area 30 of the film negative 14. Polarizer 34 is slidably mounted on support 36 and can be positioned by manipulating handle 38. Another polarizing means comprising a polarizer material, in the form of a rotatable disc 40, is shown positioned in the light path of illumination source 22 so as to be effective with respect to the entire area of film negative 14, that is both the low density portrait area 30 and the high density data area 32. The type of polarizer material utilized may be, for example, suitable polarizer sheet stock cut to required size and shape, and it will be understood that its function is that of the usual light polarizer material. Disc 40 is supported for rotation by supports 42 with means for rotation depicted as a handle 44. Of course, it will be understood that such support and rotation means can take various forms known to those skilled in the art. When light from light source 22 is transmitted by condenser lens system 24 through data area 32 of film negative 14 and polarizer 40 to printing lens 26, the printing thereby on medium will be virtually unaffected since, as is well understood in the art, a single polarizer acting alone does not substantially affect the intensity of light transmission. However, when light from light source 22 is transmitted by condenser lens system 24 through portrait area 30 of film negative 14 and both polarizer 34 and polarizer 40 to printing lens 26, the intensity of light reaching lens 26 can be attenuated by the rotation of disc 40, as indicated by arrow 46. As polarizer disc 40 is rotated by operation of handle 44 a partial crossing with respect to polarizer 34 occurs and the printing light transmitted from area 30 to lens 26, and consequently the exposure of area 30 on medium 10, is reduced by an amount determined by the degree of rotation of disc 40. It will be understood that, if desired, the intensity of light transmitted from area 30 to lens 26 can be attenuated alternatively by rotatably mounting polarizer 34 in a manner such that it can be rotated with respect to polarizer 40. To utilize such an alternative embodiment, portrait area 30 and polarizer 34 can conveniently be formed in circular shape.

By using the invention asdescribed above, the exposure of the low density area 30 of negative 14 can be readily reduced in comparison with that of thehigher density area 32 so as to attain efficient printing of the film negative 14 by a single exposure step. Since the degree of exposure differential can easily be fixed by the degree of rotation of disc 40, adjustments can readily be made as film rolls are changed, or even between negatives on the same film roll, thereby compensating for varying density differentials between portrait and data areas and achieving uniform quality in the resulting photographic prints.

' Referring now to FIG. 2 of the drawings, another embodiment of the invention is shown wherein parts corresponding to parts shown in FIG. 1' are denoted by like reference numerals followed by the suffix ,a. An apparatus is depicted for producing, by contact printing, a photographic print on a photosensitive. medium 10a from a film 12a containing a film negative 140 having separate major areas of differing densities. Photosensitive medium 10a is supported in a print exposure station, here illustrated as a surface48. Film 1221 is depicted as being supported by a film gate 50 adjacent surface 48 and medium 10a and having an aperture 52. The apparatus includes a light source 22a, a light diffusing surface 54, and

polarizers

34a and 40a, both supported in a fashion similar to that hereinbefore described in the discussion of the embodiment of FIG. 1.

In this embodiment, as with the embodiment of FIG. I, the exposure differential can be equalized by the rotation of polarizer 40a thereby compensating for varying density differentials between portrait and data areas and achieving uniform quality in the resulting photographic prints obtained by a single exposure step.

While the invention has been described with reference to printing a film negative, it is, of course, ap-

parent that other types of film transparencies or originals can be printed or copied using the same method. Also it will be appreciated that the photosensitive print material receiving the light image is not limited to photographic print material but could include various other light-sensitive, image reproducing media, such as are used for example in electrophotographic or other light recording procedures. For example, it will be apparent to those skilled in the art that the invention can be applied to copying of opaque originals, it being only necessary that the illumination source be re-positioned and proper optical element be provided in accordance with known techniques.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

I claim:

1. In apparatus for'producing on a photosensitive medium a print of an original having at least two separate major areas of respectively difference densities, the improvement comprising:

a. means for transmitting light from the original to the photosensitive medium;

b. first means for polarizing only the light transmitted from the lower density area of the original to the medium;

c. second means for polarizing the light transmitted from the entire area of the original to the medium; and

d. means for moving one of said polarizing means relative to the other of said polarizing means to attenuate the intensity of the light transmitted from the lower density area of the original without affecting any substantial attenuation of the light from the high density area of the original to allow production of a satisfactory print of the entire area with a single exposure.

2. The invention defined in claim 1 wherein the two separate major areas of respectively differing densities of the original comprise a portrait area and a data area.

3. .In apparatus including an exposure station, means spaced from the exposure station for supporting an image bearing member having two separate major areas of respectively different densities, and means for projecting light from the image bearing member to fonn an image at said exposure station, the improvement comprising:

a. first polarizing means located between said exposure station and said supporting means for polarizing light passing only from the lower density area of the supported image bearing member to said exposure station;

b. second polarizing means located between said exposure station and said supporting means for polarizing light passing from the entire area of the supported image bearing member to said exposure station; and

c. means for providing relative movement between said first polarizing means and said second polarizing means to attenuate the intensity of the light transmitted from the lower density area of the supported image bearing member to said exposure station by an amount sufficient to allow formation of an image at said exposure station representative of the major image areas which image is satisfactorily printable with a single expose. 4. The apparatus as defined in claim 3 wherein said first polarizing means comprises a sheet of polarizing sure station adapted to receive a photosensitive medium, means adjacent said exposure station for supporting a film transparency containing an image having two separate major areas of respectively different densities, and means for transmitting light through the film transparency to form an image at said exposure station, the improvement comprising:

a. first polarizing means located between said light projecting means and said film transparency supporting means for polarizing light passing only 1 through the lower density area of the film transparency to said exposure station;

b. second polarizing means located between said light projecting means and said film transparency supporting means for polarizing light passing through the entire area of the film transparency to said exposure station; and

c. means for moving said second polarizing means relative to said first polarizing means to attenuate the intensity of the light transmitted through the lower density area of the film transparency by an amount sufficient to allow formation of an image at said exposure station representative of the entire image area which is satisfactorily printable with a single exposure. 7. The contact printing apparatus as defined in claim 6 wherein said first polarizing means comprises a sheet of polarizing material corresponding in size and shape to the lower density area of the film transparency and positioned in close proximity thereto.

8. The contact printing apparatus as defined in claim 6 wherein said second polarizing means comprises a rotatable disc of polarizing material.

9. A method for producing on a photosensitive medium an' image of an original having at least two separate areas of respectively different densities, said method comprising: I

a. transmitting light from the original to the photosensitive medium; I

b. positioning a first polarizing means to render it effective to polarize light transmitted from one of the two areas to the medium;

' c. positioning a second polarizing means to render it

Claims

1. In apparatus for producing on a photosensitive medium a print of an original having at least two separate majOr areas of respectively difference densities, the improvement comprising: a. means for transmitting light from the original to the photosensitive medium; b. first means for polarizing only the light transmitted from the lower density area of the original to the medium; c. second means for polarizing the light transmitted from the entire area of the original to the medium; and d. means for moving one of said polarizing means relative to the other of said polarizing means to attenuate the intensity of the light transmitted from the lower density area of the original without affecting any substantial attenuation of the light from the high density area of the original to allow production of a satisfactory print of the entire area with a single exposure.

3. In apparatus including an exposure station, means spaced from the exposure station for supporting an image bearing member having two separate major areas of respectively different densities, and means for projecting light from the image bearing member to form an image at said exposure station, the improvement comprising: a. first polarizing means located between said exposure station and said supporting means for polarizing light passing only from the lower density area of the supported image bearing member to said exposure station; b. second polarizing means located between said exposure station and said supporting means for polarizing light passing from the entire area of the supported image bearing member to said exposure station; and c. means for providing relative movement between said first polarizing means and said second polarizing means to attenuate the intensity of the light transmitted from the lower density area of the supported image bearing member to said exposure station by an amount sufficient to allow formation of an image at said exposure station representative of the major image areas which image is satisfactorily printable with a single expose.

4. The apparatus as defined in claim 3 wherein said first polarizing means comprises a sheet of polarizing material corresponding in size and shape to the lower density area of the image bearing member and positioned in close proximity thereto.

5. The apparatus as defined in claim 3 wherein said second polarizing means comprises a rotatable disc of polarizing material.

6. In contact printing apparatus including an exposure station adapted to receive a photosensitive medium, means adjacent said exposure station for supporting a film transparency containing an image having two separate major areas of respectively different densities, and means for transmitting light through the film transparency to form an image at said exposure station, the improvement comprising: a. first polarizing means located between said light projecting means and said film transparency supporting means for polarizing light passing only through the lower density area of the film transparency to said exposure station; b. second polarizing means located between said light projecting means and said film transparency supporting means for polarizing light passing through the entire area of the film transparency to said exposure station; and c. means for moving said second polarizing means relative to said first polarizing means to attenuate the intensity of the light transmitted through the lower density area of the film transparency by an amount sufficient to allow formation of an image at said exposure station representative of the entire image area which is satisfactorily printable with a single exposure.

7. The contact printing apparatus as defined in claim 6 wherein said first polarizing means comprises a sheet of polarizing material corresponding in size and shape to the lower density area of the film transparency and positioned in close proximity thereto.

9. A method for producing on a photosensitive medium an image of an original having at least two separate areas of respectively different densities, said method comprising: a. transmitting light from the original to the photosensitive medium; b. positioning a first polarizing means to render it effective to polarize light transmitted from one of the two areas to the medium; c. positioning a second polarizing means to render it effective to polarize light transmitted from at least the one area of the original to the medium; and d. providing relative movement between said first polarizing means and said second polarizing means so that cross-polarization occurs to vary the intensity of the light transmitted from the one area of the original to the photosensitive medium.