Granted Patent B2

US 7,784,695 · App. 11/980,083 · Granted Aug 31, 2010

Assignee: Metrologic Instruments, Inc.

Abstract

Claims (25)

1. A planar laser illumination module (PLIM) comprising:

(i) a laser illumination source driven by high frequency modulated (HFM) diode current drive circuitry, for producing a laser beam having a characteristic wavelength, a coherence length, and spectral sideband components about said characteristic wavelength;

(ii) beam collimating optics disposed beyond said laser illumination source, for producing an input laser beam;

(ii) an optical beam multiplexer (OMUX) device disposed beyond said beam collimating optics, for multiplexing said input laser beam and producing multiple spatial-coherence reduced output laser beams; and

(iv) a planarizing-type illumination lens array disposed beyond said OMUX device, and arranged for receiving said multiple spatial-coherence reduced output laser beams and generating a plurality of substantially planar coherence-reduced laser illumination beams that form a composite substantially planar laser illumination beam having a substantially reduced coherence length.

2. A digital illumination and imaging system comprising:

a planar laser illumination module (PLIM) including:

(i) a laser illumination source driven by high frequency modulated (HFM) diode current drive circuitry, for producing a laser beam having a characteristic wavelength, a coherence length, and spectral sideband components about said characteristic wavelength;

(ii) a beam collimating optics disposed beyond said laser illumination source, for producing an input laser beam;

(ii) an optical beam multiplexer (OMUX) device disposed beyond said beam collimating optics, for multiplexing said input laser beam and producing multiple spatial-coherence reduced output laser beams; and

(iv) a planarizing-type illumination lens array disposed beyond said OMUX device, and arranged for receiving said multiple spatial-coherence reduced output laser beams and generating a plurality of substantially planar coherence-reduced laser illumination beams that form a composite substantially planar laser illumination beam having a substantially reduced coherence length; and

a digital image detection array for detecting digital images of an object illuminated by said composite substantially planar laser illumination beam;

wherein the power of speckle pattern noise observed in a digital image of an object detected at said digital image detection array is substantially reduced when said digital image is formed using said composite substantially planar laser illumination beam.

3. The planar laser illumination module of claim 1 , wherein said laser illumination source is selected from the group consisting of a visible laser diode (VLD) and an IR laser diode (IRLD).

4. An illumination system, comprising:

a planar laser illumination module (PLIM) including:

(i) a laser illumination source driven by high frequency modulated (HFM) current drive circuitry, for producing a laser beam having a characteristic wavelength, a coherence length, and spectral sideband components about said characteristic wavelength;

(ii) beam collimating optics disposed beyond said laser illumination source, for producing an input laser beam;

(ii) an optical beam multiplexer (OMUX) device disposed beyond said beam collimating optics, for multiplexing said input laser beam and producing multiple spatial-coherence reduced output laser beams; and

(iv) a planarizing-type illumination lens array disposed beyond said OMUX device, and arranged for receiving said multiple spatial-coherence reduced output laser beams and generating a plurality of substantially planar coherence-reduced laser illumination beams that form a composite substantially planar laser illumination beam having a substantially reduced coherence length;

wherein said laser illumination source is mounted in a support block, and said HFM diode current drive circuitry further includes a flexible HFM circuit connected to a laser diode current drive circuit.

5. The illumination system of claim 4 , wherein said laser diode current drive circuit is electrically interfaced to a printed circuit (PC) board.

6. The illumination system of claim 4 , wherein said OMUX device comprises a single glass plate bearing reflective and semi-reflective coatings to optically multiplex said input laser beam into said multiple spatial-coherence reduced output laser beams; and wherein said multiple spatial-coherence reduced output laser beams are planarized into said composite plurality of substantially planar coherence-reduced laser illumination beams by way of said planarizing-type illumination lens array being disposed in close proximity with said OMUX device.

7. The planar laser illumination module of claim 1 , wherein said OMUX device comprises a single glass plate bearing reflective and semi- reflective coatings to optically multiplex said input laser beam into said multiple spatial- coherence reduced output laser beams; and wherein said multiple spatial-coherence reduced output laser beams are planarized into said plurality of substantially planar coherence-reduced laser illumination beams by way of said planarizing-type illumination lens array being disposed in close proximity with said OMUX device.

8. The digital illumination and imaging system of claim 2 , wherein said OMUX device comprises a single glass plate bearing reflective and semi-reflective coatings to optically multiplex said input laser beam into said multiple spatial-coherence reduced output laser beams; and wherein said multiple spatial-coherence reduced output laser beams are planarized into said plurality of substantially planar coherence-reduced laser illumination beams by way of said planarizing-type illumination lens array being disposed in close proximity with said OMUX device.

Assignments (1)

Continuity (45)