Spatial light modulator assembly for adapting a photographic printer to print electronic images

• US 5,701,185 A
• Filed: 11/21/1994
• Issued: 12/23/1997
• Est. Priority Date: 11/21/1994
• Status: Expired due to Term

• Current Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Original Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Inventors: Ionson, James A., Reiss, Wanda T.
• Primary Examiner(s): Lee, Thomas D.
• Application Number:
  US08/342,824
• Time in Patent Office: 1,128 Days
• Field of Search: 358/471, 358/474, 358/401, 359/291, 359/290, 359/298, 359/244, 359/237, 359/242, 359/245, 359/275, 347/285, 347/134, 348/771, 364/822, 355/326, 355/200, 355/210, 355/211
• US Class Current: 358/471
• CPC Class Codes: G03B 27/72 Controlling or varying light intensity, spectral composition, or exposure time in photographic printing apparatus
• CPC Class Codes: H04N 1/00249 with a photographic apparatus, e.g. a photographic printer or a projector photographic apparatus per se G03B, G03D
• CPC Class Codes: H04N 1/00265 with a photographic printing apparatus

Abstract

A spatial light modulator assembly is disclosed which adapts a conventional photographic printer to generate photographic images from electronic image signal such as that created by an electronic still image camera. The spatial light modulator assembly comprises a spatial light modulator ("SLIM") which is connected to a computer for imprinting electronic image signal thereon where the electronic image signal is communicated from the computer. The SLM is secured within an adapter which is formed to fit in a negative carrier of the photographic printer such that an image imprinted on the SLM is positioned over a light source thereby projecting the image onto photographic paper held within the conventional photographic printer.

Claims

1. An apparatus, suitable for use with a photographic printer, for printing an image corresponding to an electronic image signal onto a photosensitive medium, where the photographic printer, when operating, projects a beam of light through a negative holder, said apparatus comprising:

image source means for transmitting the electronic image signal;

an adapter removeably insertable into the negative holder

spatial light modulation means disposed within said adapter, said spatial light modulation means further electrically connected to said image source means, such that said spatial light modulation means responds to the electronic image signal and forms the image in the path of the beam of light, thereby providing image-beating light to expose the image onto the photosensitive medium; and

color filter means electrically connected to said image source means, for selectively altering a color of said beam of light such that colored image-bearing light is projected onto the photosensitive medium.

2. The apparatus according to claim 1 wherein said spatial light modulation means comprises a matrix of individually addressable pixels, each of said individually addressable pixels corresponding to a location on the photosensitive medium such that the locations are two-dimensionally contiguous to form the image on the photosensitive medium with a single exposure.

3. The apparatus according to claim 1 wherein said image source means further comprises time modulation means for transmitting multiple subsets of data representing the image, where said multiple subsets are divided by gray level, and an exposure time for each consecutive subset is changeable for each consecutive subset.

4. The apparatus according to claim 1 wherein said image source means further comprises linearizing means for applying a transform function to the electronic image signal to compensate for non-linearities in said spatial light modulation means or in the photosensitive medium.

5. A system for printing an image on a photosensitive medium, said system comprising:

a light source projecting a beam of light;

a negative carrier disposed in said beam of light, said negative carrier comprising an aperture which allows said beam of light to pass therethrough;

an electronic image source adapted to transmit an electronic image signal representative of said image;

spatial modulation means disposed within said negative carrier aperture, said spatial light modulation means electrically connected to said electronic image source such that there is formed an image in said spatial light modulation means in response to the electronic image signal, and the image is projected in image-bearing light;

color filter means electrically connected to said electronic image source, for selectively altering a color of said beam of light such that a color image is projected onto the photosensitive medium; and

optical means for directing said image-bearing light onto the photosensitive medium and for controlling the exposure time of the image-bearing light thereby printing the image.

6. The apparatus according to claim 5 wherein said spatial light modulation means comprises:

a housing formed to be secured within said negative carrier with an interference fit;

said spatial light modulation means further being disposed in optical alignment with said negative carrier aperture, for selectively altering a matrix of pixels according to said electronic image signal to form a negative of the image thereon thereby selectively altering the beam of light passing therethrough to form the image upon said photosensitive medium.

7. The apparatus according to claim 6 wherein said electronic image source further comprises linearizing means for applying a transform function to said electronic image signal to compensate for non-linearities in said spatial light modulation means and in the photosensitive medium.

8. The apparatus according to claim 5 wherein said spatial light modulator means is combined with said optical means to form a single optical system electrically connected to said electronic image source, to image the electronic image signal onto the photosensitive medium where said electronic image source transmits the image to said single optical system thereby said single optical system to expose the photosensitive medium.

9. An apparatus for allowing a conventional film printer, which has a light source projecting image-beating light through an aperture in a negative carrier into a first lens system which presents the image-bearing light onto a photographic medium, to print an electronic image signal from a computer for a period of time controlled by a first shutter system, said apparatus comprising:

spatial light modulation means formed to be secured within the negative carrier in optical alignment with the aperture, said spatial light modulation means further being in electrical communication with the computer such that the electronic image signal is imprinted on the spatial light modulation means to form an image thereon thereby selectively allowing the image-bearing light to pass therethrough to render said image upon said photographic medium; and

color filter means electrically connected to the computer, for selectively altering a color of the image-bearing such that a color imagine is projected onto the photographic medium.

10. The apparatus according to claim 9 further comprising a second lens which compensates for optical variations between said spatial light modulation means and a conventional photographic negative.

11. The apparatus according to claim 10 wherein said second lens focuses said image-bearing light upon the photographic medium in conjunction with said first lens.

12. The apparatus according to claim 10 wherein said second lens is operative, after removal of said first lens, to focus said image-bearing light upon the photographic medium.

13. The apparatus according to claim 9 wherein said spatial light modulation means further comprise a second shutter which has a first and a second position, the first position being operative for blocking essentially all image-bearing light from impinging upon the photographic medium, and further being operative to move to said second position to allow said image-bearing light to expose the photographic medium and then returning to said first position, and said second shutter being operative between the first and second positions when said first shutter is fully open.

14. The apparatus according to claim 9 wherein said spatial light modulation means further comprises time modulation means for increasing a number of gray scales in the image printed on the photographic medium by subdividing the electronic image signal and transmitting a first group of least significant bits of the electronic image signal to initially expose the photographic medium, and then transmitting a second group of more significant bits of the electronic image signal to further expose the photographic medium, where exposures from the first and second groups merge on the photographic medium to form an integrated image.

15. The apparatus according to claim 14 wherein said time modulation means further comprises at least a third group of more significant bits of the electronic image signal such that exposure of said at least a third group merges with said first and second groups on the photographic medium to increase the number of gray scales.

16. An apparatus suitable for use with a conventional photographic printer, for printing an image corresponding to an electronic image signal onto a photographic medium where the conventional photographic printer, when operating, projects a beam of light through a negative holder, the beam of light then being altered by the recorded image to produce image-bearing light which passes through an optical assembly having at least a first and second removable and replaceable lens for altering magnification to expose a first and a second photographic print size, respectively, on the photographic medium, said apparatus comprising:

computer means for processing and transmitting the electronically generated image;

an adapter removably insertable into the negative holder of the conventional photographic printer;

spatial light modulation means secured within said adapter and electrically connected to said computer means, said spatial light modulation means for selectively transmitting and altering the beam of light to form the image-bearing light such that the electronically generated image is imprinted on said spatial light modulation means and is thereby projected in image-bearing light; and

color filter means electrically connected to said computer means, for selectively altering a color of said beam of light such that a color image is projected onto the photographic medium.

17. The apparatus according to claim 16, said apparatus comprising dimensions such that the first lens projects the image onto the photographic medium as a print substantially equal to that of the first print size, and the second lens projects the image onto the photographic medium as a print substantially equal to that of the second print size.

18. The apparatus according to claim 16, said apparatus comprising dimensions such that the second lens projects an image onto the photographic medium as a print substantially equal to that of the first print size.

19. An adapter for allowing a conventional film printer having a light source projection image-bearing light through an aperture in a negative carrier into a first lens system which presents the image-bearing light onto a photographic medium to print electronic image signal from a computer for a period of time controlled by a first shutter system, said adapter comprises:

spatial light modulation means formed to be secured within the negative carrier in optical alignment with said aperture, the spatial light modulation means in electrical communication with said computer such that the electronic image signal is imprinted on the spatial light modulation means forming an image thereon thereby selectively allowing the image-bearing light to pass therethrough to render said image upon said photographic medium; and

modulation means for increasing a number of gray scales in the image printed on the photographic medium by subdividing the electronic image signal and transmitting a first group of least significant bits of the electronic image signal to expose the photographic medium and then transmitting a second group of more significant bits of the electronic image signal to expose the photographic medium where exposures from the first and second groups merge on the photographic medium to form an integrated image.