US 6,177,683 B1 · Portable viewer for invisible bar codes

Abstract

A portable viewer for viewing bar codes and other markings printed at least in part with invisible inks includes a light source for illuminating and exciting the ink of the bar code, a camera for detecting light emitted by the excited bar code and for outputting image data, a display for creating a visible image of the bar code from the image data output from the camera, and an optical system for projecting the visible image onto a viewing screen. The display may be a miniature, transmissive active matrix liquid crystal display with high resolution that produces a sharp, bright image. A backlight and lens project the image produced by the display to generate an enlarged virtual image that can be easily viewed by a user. The portable viewer is compact in size and can be accommodated in a small package and requires only a small amount of power.

Claims24

Dependent claims

A portable viewer for viewing markings that are at least partially invisible ink markings, the invisible ink emitting light at an emission frequency in response to light of an excitation frequency being impinged thereon, comprising:

a) a light source for generating light at the excitation frequency;
b) a camera sensitive to light at said emission frequency for detecting the image created by said emitted light in response to light from said light source impinging upon the invisible ink;
c) a display for displaying, in the visible spectrum, the image detected by said camera;
and
d) a magnifying optical system disposed between said display and the user for magnifying the image on said display.

2 more elements

A portable viewer for viewing invisible ink markings, the invisible ink emitting light at an emission frequency in response to light of an excitation frequency being impinged thereon, comprising:

a) a plurality of light emitting diodes for generating light at the excitation frequency;
b) a camera sensitive to light at said emission frequency for detecting the image created by said emitted light in response to light from said light source impinging upon the invisible ink;
c) a filter in the optical path leading to said camera, said filter selectively allowing light having a frequency in a predetermined frequency band to pass therethrough to said camera;
said frequency band including said emission frequency;
said filter substantially blocking light at the excitation frequency;
d) a transmissive LCD display for displaying, in the visible spectrum, the image detected by said camera;
e) a backlight for said display;
f) a magnifying optical system disposed between said display and the user of the viewer for magnifying the image on said display for the user by at least five times;
g) a housing enclosing said light source, said camera, said display, said backlight, and said magnifying optical system;
and
h) wherein said backlight and said display consume not more than approximately 20 mW combined.

8 more elements

Dependencies are inferred from the claim text.

Portable viewer for invisible bar codes

Life of this patent

Portable viewer for invisible bar codes

Life of this patent

Abstract

Claims24