Imaging device

Patent metadata

Field	Value
Publication number	US-10061200-B2
Application number	US-201615363129-A
Country	US
Kind code	B2
Filing date	Nov 29, 2016
Priority date	May 27, 2015
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

An imaging device for projecting individually controllable laser beams onto an imaging surface movable in an X-direction. The device includes a plurality of semiconductor chips each comprising a plurality of laser beam emitting elements arranged in a main array of M·N. The chips are mounted such that each pair of adjacent chips in the Y-direction are offset from one another in the X-direction and, if activated continuously, the emitted laser beams of the two chips of said pair trace on the imaging surface a set of parallel lines that are substantially uniformly spaced in the Y-direction. In addition to the M·N elements of the main array, each chip comprises at least one additional column on one or each side, each additional column containing at least one selectively operable element capable of compensating for any misalignment in the Y-direction in the relative positioning of the adjacent chips on the support.

First claim

The invention claimed is:

1. An imaging device for projecting individually controllable laser beams onto an imaging surface, the imaging device and imaging surface being movable relative to each other in a reference X-direction, the imaging device comprising:
a plurality of semiconductor chips each of which comprises a plurality of individually controllable laser beam emitting elements arranged in a two dimensional main array of M rows and N columns, the emitting elements in each row having a uniform spacing Ar and the emitting elements in each column having a uniform spacing ac;
wherein the chips are mounted on a support such that the main arrays of each pair of chips that are adjacent one another in a reference Y-direction, transverse to the X-direction, are offset from one another in the X-direction, wherein when the chips are nominally placed, were all the emitting elements of the main arrays of the two chips to be activated continuously and the imaging surface and the imaging device relatively moved in the X-direction, the emitted laser beams of the respective main arrays of the two chips of the pair, would trace on the imaging surface 2·M·N parallel lines that extend in the X-direction and are uniformly spaced from one another in the Y-direction by a nominal distance Ar/M, whereby the laser beams of each chip tracing a set of M·N lines without overlapping the set of lines of the other chip; and,
each chip further comprises at least one additional column in addition to the N columns of elements of the main array, the additional column being disposed on at least one side of the main array along the Y-direction, and containing at least one selectively operable laser emitting element capable of tracing at least one additional line that lies between the respective sets of M·N lines of each pair of chips and that is passed from two adjacent lines, each from a respective one of the sets, by a distance smaller than the uniform element spacing in each row Ar.

2. An imaging device as claimed in claim 1 , wherein the at least one additional column comprises a plurality of elements.

3. An imaging device as claimed in claim 2 , wherein when the imaging surface and the imaging device are relatively moved in the X-direction and the elements of the additional column are continuously activated, the resulting laser beams trace nominally uniformly spaced lines, the spacing between the lines traced by the elements of additional columns and disposed between lines traced by elements of the main arrays being substantially equal to the quotient of the spacing of the lines traced by the elements of the main array (Ar/M) and one more than the total number of elements in the additional columns.

4. An imaging device as claimed in claim 1 , wherein the elements in each row of each chip lie on a line parallel to the Y-direction and the elements in each column of each chip lie on a straight line inclined at an angle to the X-direction.

5. An imaging device as claimed in claim 1 , wherein the chips are arranged in pair of rows on the support and corresponding laser emitting elements of all the chips in each of the two rows lying in line with one another in the Y-direction.

6. An imaging device as claimed in claim 5 , further comprising a plurality of lens systems, each serving to focus the laser beams of all the laser elements of a respective one of the chips onto the imaging surface, each lens system comprising at least one gradient index (GRIN) rod; and,
the chips within the two rows of the pair being aligned such that corresponding elements in any group of three adjacent chips in the X and Y-directions lie at the apices of congruent equilateral triangles and the distance in the Y-direction between corresponding elements is nominally equal to N·Ar.

7. An imaging device as claimed in claim 6 , wherein the GRIN rod is of circular cross-section having a diameter equal to 2·N·Ar.

8. An imaging device as claimed in claim 6 , wherein the lens systems have a magnification of absolute value equal or greater than 1.

9. An imaging device as claimed in claim 6 , wherein the lens systems magnification value is +1 or −1.

10. An imaging system as claimed in claim 6 , wherein each lens system is formed by a plurality of mutually inclined GRIN rods.

11. An imaging system as claimed in claim 10 , wherein light from each GRIN rod is directed to the next GRIN rod in the plurality of rods of the same lens system by at least one reflecting member.

12. An imaging system as claimed in claim 11 , in which the reflecting member is a prism having a higher refractive index than the highest refractive index of the GRIN rods.

13. An imaging device as claimed in claim 1 , wherein each chip comprises at least a second additional column, such that at least one additional column is disposed on each side of the respective main array.

14. An imaging device as claimed in claim 1 , wherein the support is fluid-cooled.

15. An imaging device as claimed in claim 1 , wherein the support is constructed of a rigid metallic or ceramic structure.

16. An imaging device as claimed in claim 1 , further comprising at least one lens associated with each chip of the pair of chips, wherein the respective lens focuses the laser beams emitted by all the elements of the associated chip onto the imaging surface.

17. An imaging device as claimed in claim 1 , wherein each chip has an equal number of rows and columns of laser beam emitting elements in the main array.

18. An imaging device as claimed in claim 1 , wherein the surface of the support is formed of, or coated with, an electrical insulator, and further comprising a plurality of thin film conductors formed on the electrically insulating surface for supplying electrical signals and power to the chips.

19. An imaging device as claimed in claim 1 , wherein the laser emitting elements are a vertical cavity surface emitting lasers (VCSEL) array.

20. An imaging device as claimed in claim 1 , wherein each individually controllable laser beam element can emit a laser beam of at least four selectable levels of energy.

Assignees

• Landa Labs 2012 Ltd

Inventors

• Rubin Ben Haim Nir
• Nagler Michael
• Landa Benzion
• Kashti Tamar
• Aknin Ofer
• Yogev Ronen
• Tzur Itai

Classifications

• B41J2/45

  using light-emitting diode {[LED] or laser} arrays · CPC title

• G03G15/04072 Primary

  by laser · CPC title

• H01S5/4025

  Array arrangements, e.g. constituted by discrete laser diodes or laser bar (H01S5/42 takes precedence) · CPC title

• B41J2/447 Primary

  using arrays of radiation sources (B41J2/475 takes precedence) · CPC title

• B41J2/451

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