VCSEL-based variable image optical line generator

Patent metadata

Field	Value
Publication number	US-9630424-B2
Application number	US-201514681957-A
Country	US
Kind code	B2
Filing date	Apr 8, 2015
Priority date	Aug 24, 2011
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

A single-pass imaging system utilizes a two-dimensional (2D) light field generator (e.g., one or more VCSEL devices) to generate a modulated two-dimensional modulated light field in accordance with image data for a single row of pixels, and an anamorphic optical system that concentrates the two-dimensional modulated light field in a process direction such that a one-dimensional scan line image extending in a cross-process direction is generated on an imaging surface. The VCSEL array is configured using a scan line image data group made up of pixel image data portions, with associated groups of light emitting elements aligned in the process direction being configured by each pixel image data portion. Gray scaling is achieved either by turning on some of the light emitting elements of the associated group, or by turning the light emitting elements of the associated group partially on, e.g. using a common drive current.

First claim

The invention claimed is:

1. A single-pass imaging system comprising:
a two-dimensional light field generator including:
a plurality of light emitting elements disposed in a two-dimensional array, each light emitting element being adjustable between two or more modulated states such that, when said each light emitting element is in a first modulated state said each light emitting element transmits an associated modulated light portion having a first intensity, and when said each light emitting element is in a second modulated state said each light emitting element transmits said associated light portion having a second intensity, said second intensity being lower than said first intensity, and wherein each light emitting element is arranged to direct said associated light portion in a corresponding predetermined direction, whereby said plurality of light emitting elements generate a modulated two-dimensional light field, and
a controller configured to control the plurality of light emitting elements in accordance with received image data; and

an anamorphic optical system positioned to receive said modulated two-dimensional light field from said two-dimensional light field generator, and arranged to concentrate said associated light portions transmitted from said each light emitting element such that the concentrated modulated light portions produce an elongated scan line image,
wherein the plurality of light emitting elements are arranged in a plurality of rows and a plurality of columns, wherein all of said light emitting elements in each said column forms an associated pixel group,
wherein the anamorphic optical system is arranged to concentrate modulated light portions received from each associated pixel group of said plurality of light emitting elements onto an associated said scan line portion of said elongated scan line image,
wherein the anamorphic optical system includes a cross-process optical subsystem and a process-direction optical subsystem,
wherein the cross-process optical subsystem includes first and second focusing lenses arranged to project and magnify said modulated light portions only in a cross-process direction,
wherein the process-direction optical subsystem includes a third focusing lens arranged to concentrate said modulated light portions on said elongated scan line image parallel to a process direction, and
wherein each of the first, second and third focusing lenses comprises one of a cylindrical lens and an acylindrical lens.

2. The imaging system according to claim 1 , wherein the anamorphic optical system further comprises a collimating lens disposed between the two-dimensional light field generator and the plurality of focusing lens.

3. The imaging system according to claim 1 , wherein said two-dimensional light field generator comprises a plurality of vertical-cavity surface-emitting laser (VCSEL) devices disposed in an array.

4. The imaging system according to claim 3 , wherein each said associated pixel group comprises an aligned set of said light emitting elements that are disposed on two or more VCSEL devices.

5. A single-pass imaging system comprising:
a two-dimensional light field generator including:
a plurality of light emitting elements disposed in a two-dimensional array, each light emitting element being adjustable between two or more modulated states such that, when said each light emitting element is in a first modulated state said each light emitting element transmits an associated modulated light portion having a first intensity, and when said each light emitting element is in a second modulated state said each light emitting element transmits said associated light portion having a second intensity, said second intensity being lower than said first intensity, and wherein each light emitting element is arranged to direct said associated light portion in a corresponding predetermined direction, whereby said plurality of light emitting elements generate a modulated two-dimensional light field, and
a controller configured to control the plurality of light emitting elements in accordance with received image data; and

an anamorphic optical system positioned to receive said modulated two-dimensional light field from said two-dimensional light field generator, and arranged to concentrate said associated light portions transmitted from said each light emitting element such that the concentrated modulated light portions produce an elongated scan line image,
wherein the anamorphic optical system includes a cross-process optical subsystem and a process-direction optical subsystem,
wherein the cross-process optical subsystem includes first and second focusing lenses arranged to project and magnify said modulated light portions only in a cross-process direction, and
wherein the process-direction optical subsystem includes a third focusing lens arranged to concentrate said modulated light portions on said elongated scan line image parallel to a process direction, and
wherein each of the first, second and third focusing lenses comprises one of a cylindrical lens and an acylindrical lens.

6. The imaging system according to claim 5 , wherein said two-dimensional light field generator comprises one of a multi-mode vertical-cavity surface-emitting laser (VCSEL) device and a single mode VCSEL device.

7. The imaging system according to claim 5 ,
wherein said controller is configured to generate a plurality of drive currents, each drive current corresponding to an associated pixel image data value,
wherein all of said light emitting elements in each said column forming an associated said pixel group receive an associated said shared drive current transmitted to said all of said light emitting elements from said controller.

8. The imaging system according to claim 5 , wherein the anamorphic optical system further comprises a collimating lens disposed between the two-dimensional light field generator and the plurality of focusing lens.

Assignees

• Palo Alto Res Ct Inc

Inventors

• Stowe Timothy David
• Biegelsen David K
• Maeda Patrick Y
• Chua Christopher L

Classifications

• B41J2/455

  using laser arrays {, the laser array being smaller than the medium to be recorded} · CPC title

• B41J2/47 Primary

  using the combination of scanning and modulation of light · CPC title

• B41J2/451 Primary

  Special optical means therefor, e.g. lenses, mirrors, focusing means · CPC title

• G02B13/22

  Telecentric objectives or lens systems · CPC title

• B41J2/44

  using single radiation source {per colour}, e.g. lighting beams or shutter arrangements (B41J2/475 takes precedence) · CPC title