MANUALLY OPERATED LAMPHOUSE

• US 3,818,216 A
• Filed: 03/14/1973
• Issued: 06/18/1974
• Est. Priority Date: 03/14/1973
• Status: Expired due to Term

• Current Assignee: Philippe M. Larraburu
• Original Assignee: Philippe M. Larraburu
• Inventors: Larraburu, Philippe M.
• Primary Examiner(s): Moses, Richard L.
• Application Number:
  US05/341,155
• Time in Patent Office: 461 Days
• Field of Search: 240/41.3,46.03,46.01,46.59,41R,3.1 350/314,311 355/35,36,38,67,71,88
• US Class Current: 362/301
• CPC Class Codes: G02B 27/1006 for splitting or combining different wavelengths G02B27/1086, G02B27/141 take precedence
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: G03B 27/73 Controlling exposure by variation of spectral composition, e.g. multicolor printers

Abstract

A manually operated lamphouse for providing light color control and intensity for improving, the quality of negative films in printing, for example, includes a broad spectrum tungsten lamp the intensity of which is manually controllable. Dichroic mirrors are utilized to separate the broad spectrum of the lamp into first, second, and third colors. Individual attenuation controls in turn operable from the exterior of the lamp housing enable the intensity of the individual colors to be controlled. The colors are then recombined and passed out a projection axis through a lenticular lens system to integrate the recombined beam to provide a uniform output beam. The color content and intensity of the output beam can thus be manually controlled in accord with various operations to be performed such as the printing of film.

Claims

1. A manually operated lamphouse for providing light color control and intensity comprising, in combination:

a. a broad spectrum light source;

b. manually operable light source intensity control means connected to said light source;

c. means for separating the broad spectrum of said light source into first, second, and third spectral portions corresponding to first, second, and third colors which when recombined form substantially white light, said means including, a first dichroic mirror positioned on said given path to intercept said light at 45* and direct out from the path at 90* the first spectral portion corresponding to the first color and pass the second and third spectral portions along the given path; and

, a second dichroic mirror positioned on said given path to intercept said second and third spectral portions at 45* and direct out from the path at 90* said second spectral portion corresponding to said second color and pass the third spectral portion corresponding to the third color along the path;

d. manually controllable first, second, and third attenuating control means for individually varying the intensity of said first, second, and third spectral portions including first, second, and third pairs of counter-rotatable optical wedges positioned to intercept said first, second, and third spectral portions respectively; and

e. integrating means receiving and recombining said first, second, and third portions to provide an output light beam in which the overall intensity and relative color content are determined by the manual setting of said manually operable light source intensity control means and the individual settings of the first, second, and third attenuation control means said integrating means including;

optical means intercepting the first, second, and third spectral portions and re-collimating them along a projection axis, and lenticular lens means positioned on said projection axis for providing multiple projected images of the lamp filament in an image plane which images all overlap to provide said output light beam.

2. A lamphouse according to claim 1, in which said optical means includes two totally reflecting mirrors positioned at 45* to said given path to intercept said first spectral portion and direct it along said projection axis and intercept said third spectral portion at 45* and direct it in a direction parallel to said second spectral portion;

and two half reflecting and half transmitting mirrors positioned on said projection axis at 45* to intercept respectively said second and third spectral portions and direct them along said projection axis, said first spectral portion from said first totally reflecting mirror recombining with said second spectral portion at said first half reflecting and half transmitting mirror, and said first and second spectral portions recombining with said third spectral portion from said second totally reflecting mirror at said second half reflecting and half transmitting mirror so that all three spectral portions pass out along said projection axis to said integrating means.

3. A lamphouse according to claim 2, including first, second, and third projection lenses positioned respectively to intercept said first, second, and third spectral portions and image the same in a common plane on said projection axis for projection by said lenticular lens means.

4. A lamphouse according to claim 3, including a housing for said light source, means for separating the broad spectrum of said light source, and manually controllable first, second, and third attenuation control means, said housing including exterior knobs for manual rotation coupled to the first, second, and third attenuation control means.

5. A lamphouse according to claim 2, in which said pairs of counter-rotatable optical wedges are positioned with their axes at a slight angle to the optical path to avoid multiple reflections and wherein the optical wedge of each pair has a varying density in a circumferential direction, the two wedges making up the pairs being oppositely oriented so that the circumferential directions of increasing density are opposite to each other so that attenuation of a spectral portion passing through the counter-rotatable wedges remains substantially uniform over the cross sectional area of the spectral portion.