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Patent

Laser Projection Apparatus

US 5,136,426

A way to build a large, full-color video image out of red, green, and blue laser light — combining and balancing the beams through an optical system so the projected picture is bright, sharp, and correctly colored.

The drawing, explained

What the figure shows

FIG. 3 of U.S. Patent 5,136,426, annotated: the dye laser (red source), two argon-ion lasers (green and blue), the scanner, and the projection optics that cast the image onto the screen.
  1. 1 Dye laser — the red light source
  2. 2 Argon-ion laser — a green / blue source
  3. 3 Argon-ion laser — the other green / blue source
  4. 4 Scanner — sweeps the combined beam into a raster
  5. 5 Projection optics — focus the image onto the screen (S₂)
FIG. 3 — how the three laser sources are combined and cast as one full-color image. U.S. Patent 5,136,426, FIG. 3 — U.S. Patent and Trademark Office · Annotations added for clarity; the drawing is the original figure.
FIG. 3 of U.S. Patent 5,136,426 — a schematic of the laser projection apparatus: two lasers and a dye laser combined through mirrors and lenses onto a rotating scanner and projection optics.
FIG. 3 — the laser projection apparatus (sheet 2 of 4). U.S. Patent and Trademark Office
Drawing sheet 3 of 4 from U.S. Patent 5,136,426.
Sheet 3 of 4. U.S. Patent and Trademark Office
Drawing sheet 4 of 4 from U.S. Patent 5,136,426.
Sheet 4 of 4. U.S. Patent and Trademark Office
View full patent on Google Patents →
Patent number
US 5,136,426
Issued
August 4, 1992
Inventors
Paul A. Linden
Assignee
Advanced Laser Projection, Inc.

U.S. Patent 5,136,426, “Laser Projection Apparatus,” is the cornerstone of Paul’s invention story, assigned to Advanced Laser Projection, Inc. It describes a system for producing balanced, full-color projected imagery using lasers as the light source.

What it does, in plain English

The patent was developed to maximize the various wavelengths of two argon lasers and a dye laser — tuning and combining them to provide the best color balance of the red, green, and blue laser beams, for the brightest image and the best color saturation. Building a color picture from lasers means precisely converging those beams and controlling their brightness moment to moment, so the final projected image is bright, sharp, and correctly colored — at a scale and depth of focus conventional lamp-based projectors of the era could not reach.

A family date

The patent was issued on August 4, 1992 — the birthday of Paul’s wife, Elaine Linden. Paul is especially proud of the coincidence, and likes to point out that his most important patent shares such a meaningful family date.

The full patent, including its claims and figures, is available from the USPTO and Google Patents.

Technical abstract

The patent covers aspects of a laser projection system intended to create balanced full-color projected imagery using laser light sources and associated optical components.

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