Daylight photoplotting and film therefor

United States Patent [19]

Webster

[ii] 4,416,522 [45] Nov. 22, 1983

[54] DAYLIGHT PHOTOPLOTTING AND FILM THEREFOR

[75] Inventor: Ronald B. Webster, Ellington, Conn.

[73] Assignee: The Gerber Scientific Instrument Company, South Windsor, Conn.

[21] Appl. No.: 342,195

[22] Filed: Jan. 25, 1982

[51] Int. CI.3 G03B 41/00

[52] U.S. CI :354/4; 355/32;

430/338

[58] Field of Search 354/4; 355/32; 430/338,

430/363, 506; 346/108; 250/316.1, 319, 327.2,

329

[56] References Cited

U.S. PATENT DOCUMENTS

2,509,766 5/1950 Gross 430/363

3,061,722 10/1962 Mittelstaedt 430/363

3,849,138 11/1974 Wyckoff 430/506

4,112,459 9/1978 Gautier et al. .

4,170,745 10/1979 Rich et al 354/4

4.249.807 2/1981 Webster et al 354/4

4.249.808 2/1981 Webster 354/4

Primary Examiner—A. A. Mathews

Attorney, Agent, or Firm—McCormick, Paulding &

Huber

[57] ABSTRACT

A photosensitive film for plotting color images in daylight uses surface emulsion layers sensitive only to different and predetermined wavelengths of non-visible radiant energy. Each emulsion layer is developable to manifest a distinguishable color upon exposure to sensitizing radiant energy. Three sensitized emulsion layers can singly and collectively manifest any color upon development. During a plotting operation in daylight, a beam of radiant energy having a controlled composition of radiant energy wavelengths outside the visible spectrum is projected onto the film surface in the form of a spot. The beam of radiant energy and the film are moved relative to one another to cause the spot to sensitize the emulsion layers at different locations according to the desired plot. Changing the composition of the sensitizing wavelengths comprising the beam during a plotting operation causes the film to yield a multi-colored image upon development.

8 Claims, 4 Drawing Figures

DAYLIGHT PHOTOPLOTTING AND FILM
THEREFOR

BACKGROUND OF THE INVENTION 5

This invention relates to a plotting apparatus, method and film for recording color images, and deals more particularly with a photoplotting apparatus, method and film utilizing non-visible radiant energy, that is, radiant energy outside the visible wavelength region of 1C the radiant energy spectrum to plot in daylight conditions. Within the scope of the specification, daylight includes natural and artificial illumination at light levels rendering objects visible to the unaided eye.

A method for plotting graphic images in color on a 15 photosensitive surface is described in U.S. Pat. No. 4,249,807 by Webster and Larson, and employs a photoplotting apparatus having an optical exposure head to project a beam of radiant energy having different or changeable color components onto the photosensitive 20 surface of a film. Various emulsion layers defining the photosensitive surface record the color components of the projected beam. Drive motors within the apparatus, or photoplotter, move the spot of radiant energy generated by the beam over the film surface and expose the 25 film in accordance with the color components of the beam.

Typically, color film used in photoplotting includes three emulsion layers for recording the color components of a projected beam. The color of any beam may 30 be defined by various amounts of magenta, cyan, and yellow light, the subtractive primary colors, in the beam, and it is common for each of the three emulsion layers in the film to record a respective one of the three primary colors. "35

The plotting operation using conventional color film must be performed in a low light-level room to avoid exposure of the emulsion layers by the magneta, cyan and yellow color components of the visible light spectrum. An obvious disadvantage associated with plotting 40 in a low light-level environment is that it is difficult for the operator to see. Additionally, special darkrooms must be provided for the plotting function, and control over ingress and egress to the room must be maintained to prevent inadvertent admission of outside light while 45 a plotting operation is underway. The film must also receive special handling when the darkroom conditions do not prevail.

It is, therefore, a general object of this invention to provide a film for recording color images in a daylight 50 or lighted environment and a method and apparatus for plotting on the film in this environment.

SUMMARY OF THE INVENTION

The present invention relates to a photoplotting 55 method and apparatus and photosensitive film for recording colored images in a daylight or lighted environment.

The film of this invention includes sheet material having a plurality of emulsion layers in overlying rela- 60 tionship. Each of the emulsion layers is sensitive only to predetermined wavelengths of non-visible radiant energy and the wavelengths are different for each emulsion. The wavelengths, for example, may lie in the infrared or ultraviolet regions of the energy spectrum. Each 65 emulsion upon exposure to sensitizing radiant energy is developable to manifest a distinguishable color different from the other emulsions. In one embodiment, there are

2

three emulsion layers and the different and distinguishable colors manifested by the emulsion layers are the subtractive primary colors magneta, cyan and yellow.

The apparatus for plotting on the color film of this invention includes the color film as an integral component. The apparatus further includes a support surface on which the color film is spread, a radiant energy source for sensitizing at least one of the film emulsion layers, and means for projecting the radiant energy emitted from the source along a beam axis and onto a spot on the film surface. Support means support the source and the projecting means so that the beam axis is generally perpendicular to the support surface. Motive means move the film and spot relative to one another to expose locations on the film in accordance with a desired plot.

In a further embodiment of the apparatus, the radiant energy source is capable of sensitizing all of the film emulsion layers, and the apparatus further includes a wavelength filter supported in the beam path which allows only desired emulsion layers to be sensitized.

In still a further embodiment of the apparatus, the apparatus has a plurality of radiant energy sources respectively capable of sensitizing different emulsion layers and includes means for bringing the sources separately into registration with the beam so that a plot of at least two colors is produced.

The method of this invention employs the color film of this invention in a plotting operation. One embodiment of the method includes the steps of projecting a beam of radiant energy having wavelengths capable of sensitizing all of the emulsion layers toward the surface of the color film and filtering wavelengths from the beam to allow only the emulsion layers collectively capable of manifesting a particular color upon development to be sensitized. The beam of radiant energy is projected as a spot on the film surface, and the beam and color film are moved relative to one another to sensitize the emulsion layers at different locations according to the desired plot of a particular color image. Further, the wavelength filtering is changed on occasion to alter the sensitizing of the emulsion layers so that upon development the plot of a multi-colored image is manifested.

In an alternative embodiment of the method, different beams of radiant energy, each capable of sensitizing the emulsion layers in different amounts and degrees, are selectively projected toward the surface of the color film. Each beam strikes the surface of the film in the form of a spot, and the spot and color film are moved relative to one another to sensitize the emulsion layers at different locations according to the desired plot of a multi-colored image.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a photoplotter incorporating the features of the present invention.

FIG. 2 is a plan view of a wavelength filter disc utilized in the photoplotter of FIG. 1.

FIG. 3 is a schematic illustration of another photoplotter incorporating the features of the present invention.

FIG. 4 is an enlarged fragmentary perspective view of the color film in one embodiment of the invention.