Non mechanical optical beam steering mechanism for laser printers

• US 10,345,677 B1
• Filed: 06/22/2018
• Issued: 07/09/2019
• Est. Priority Date: 06/22/2018
• Status: Active Grant

• Current Assignee: Capital One Services LLC (Capital One Financial Corporation)
• Original Assignee: Capital One Services LLC (Capital One Financial Corporation)
• Inventors: Wurmfeld, David
• Primary Examiner(s): Feggins, Kristal
• Assistant Examiner(s): Liu, Kendrick X
• Application Number:
  US16/015,912
• Time in Patent Office: 382 Days
• CPC Class Codes: B41J 2/442 using lasers
• CPC Class Codes: B41J 2/445 using liquid crystals
• CPC Class Codes: B41J 2/47 using the combination of scanning and modulation of light
• CPC Class Codes: B41J 2/471 using dot sequential main scanning by means of a light deflector, e.g. a rotating polygonal mirror
• CPC Class Codes: B41J 2202/50 Embodiments of processes related to optical heads
• CPC Class Codes: G02B 2006/0098 for scanning
• CPC Class Codes: G02B 26/0808 by means of one or more diffracting elements
• CPC Class Codes: G02B 26/0875 by means of one or more refracting elements
• CPC Class Codes: G02B 26/0891 forming an optical wedge
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G02B 26/103 having movable or deformable optical fibres, light guides or waveguides as scanning elements light guides per se G02B6/00
• CPC Class Codes: G02B 26/108 having one or more prisms as scanning elements
• CPC Class Codes: G02B 27/0977 Reflective elements
• CPC Class Codes: G02B 27/30 Collimators
• CPC Class Codes: G02F 1/295 Analog deflection from or in an optical waveguide structure]
• CPC Class Codes: G02F 2203/24 beam steering
• CPC Class Codes: H04N 1/0282 Using a single or a few point light sources, e.g. a laser diode
• CPC Class Codes: H04N 1/23 Reproducing arrangements
• CPC Class Codes: H04N 1/295 Circuits or arrangements for the control thereof, e.g. using a programmed control device, according to a measured quantity

Abstract

A laser printing system includes a laser configured to produce a beam of light modulated according to image data input to the laser printing system, a photoreceptor drum including a photoconductive layer disposed along an outer peripheral surface of the photoreceptor drum, and a non-mechanical beam steerer configured for receiving the modulated light beam from the laser and steering the light beam in a scanning motion back and forth across the photoconductive layer of the photoreceptor drum. The laser printing system also includes a printer controller configured to structure the image data input to the laser printing system, and control an amount of electrical current flowing through portions of the non-mechanical beam steerer to change an effective index of refraction of the non-mechanical beam steerer and steer the modulated light beam in the scanning motion.

Claims

1. A laser printer, comprising:

a laser configured to produce a light beam;

a modulator configured to modulate the light beam according to image data supplied to the laser printer;

a photoreceptor drum comprising a photoconductive layer disposed along an outer peripheral surface of the drum; and

a non-mechanical beam steerer comprising;

a waveguide core for guiding the modulated light beam through the beam steerer;

a cladding layer comprising a liquid crystal material disposed therewithin; and

a substrate comprising at least one of silicon or an insulator; and

a controller configured to control a refractive index of the liquid crystal material so as to steer the modulated light beam in a scanning motion back and forth across the photoreceptor drum.

2. The laser printer of claim 1, wherein the non-mechanical beam steerer further comprises a lower cladding layer formed along a top surface of the substrate and along a bottom surface of the waveguide core.

3. The laser printer of claim 2, wherein:

the cladding layer comprising the liquid crystal material forms

an upper liquid crystal cladding layer along a top surface of the waveguide core; and

the non-mechanical beam steerer further comprises

an upper electrode deposited along an upper surface of the upper liquid crystal cladding layer.

4. The laser printer of claim 3, wherein:

the upper electrode is formed from Indium-Tin-Oxide (ITO); and

the substrate comprises a lower electrode formed below the upper liquid crystal cladding layer.

5. The laser printer of claim 3, wherein the non-mechanical beam steerer further comprises a cover glass positioned along a top surface of the upper liquid crystal cladding layer.

6. The laser printer of claim 5, wherein:

the non-mechanical beam steerer further comprises a housing configured to contain the substrate, the lower cladding layer, the waveguide core, the upper liquid crystal cladding layer, and the cover glass; and

the housing comprises a beam entrance window aligned with one end of the waveguide core and a beam exit window aligned with an opposite end of the waveguide core.

7. The laser printer of claim 1, further comprising:

a collimator lens configured to form the light beam into a collimated light beam with parallel rays; and

at least one focus lens configured to focus the light beam onto the photoconductive layer and compensate for different distances between the non-mechanical beam steerer and points along the photoconductive layer of the photoreceptor drum.

8. The laser printer of claim 1, wherein:

the substrate comprises

a silicon substrate;

the waveguide core comprises

an optical waveguide core;

the non-mechanical beam steerer further comprises

a lower cladding layer formed on the substrate below the waveguide core; and

the cladding layer comprising the liquid crystal material forms

an upper cladding layer along an upper side of the waveguide core; and

the laser printer further comprises

a power supply applying an electric voltage across the upper cladding layer so as to cause the upper cladding layer to deflect light passing along a face of the liquid crystal material as the light propagates through the waveguide core.

9. The laser printer of claim 8, wherein the non-mechanical beam steerer further comprises:

a cover glass provided over the upper liquid crystal cladding layer;

a housing containing the substrate, the lower cladding layer, the waveguide core, the upper cladding layer, and the cover glass;

a beam entrance window formed through the housing at a first end of the waveguide core, the beam entrance window being aligned with an entrance to the waveguide core and configured to receive the light beam; and

a beam exit window formed through the housing at a second end of the waveguide core.

10. The laser printer of claim 8, wherein the upper cladding layer comprises a liquid crystal material which deflects infrared wavelengths of light when an electric voltage is applied across the upper cladding layer.

11. The laser printer of claim 1, further including:

a pre-charger configured to donate static positive electrical charges onto the photoconductive layer to create a uniformly spread positive charge across the surface of the photoreceptor drum; and

a corona wire configured to donate static negative electrical charges onto recording medium carried by a belt past the photoreceptor drum.

12. The laser printer of claim 1, further comprising a printer controller configured to:

organize the image data into pages of information to be printed on recording medium by setting text margins, and arranging words and graphics;

process the image data by converting the image data into dot image data;

feed the dot image data one horizontal line at a time to the modulator;

activate the laser and modulator to output a pulsed light beam to the non-mechanical beam steerer, with one pulse of light from the laser for every dot to be printed; and

control an amount of electrical current flowing through the non-mechanical beam steerer to change an effective index of refraction of the non-mechanical beam steerer and steer the light beam in the scanning motion.

13. A non-mechanical optical beam steering mechanism for scanning a laser light beam of a laser printer across a photoconductive layer on a photoreceptor drum of the laser printer, wherein the laser light beam is modulated according to image data provided to the laser printer, the non-mechanical optical beam steering mechanism comprising:

a waveguide core for guiding the laser light beam through the non-mechanical optical beam steering mechanism;

a first cladding layer disposed on a side of the waveguide core, the first cladding layer comprising a liquid crystal material;

a substrate supporting the waveguide core and the first cladding layer, the substrate being made from at least one of silicon or an insulator; and

a control system configured to control a refractive index of the liquid crystal material so as to scan the modulated laser light beam back and forth across the photoconductive layer on the photoreceptor drum.

14. The beam steering mechanism of claim 13, further comprising a second cladding layer formed along a top surface of the substrate and along a bottom surface of the waveguide core.

15. The beam steering mechanism of claim 14 further comprising an upper electrode deposited along an upper surface of the first cladding layer formed along a top surface of the waveguide core.

16. The beam steering mechanism of claim 15, wherein:

the upper electrode is formed from Indium-Tin-Oxide (ITO); and

the substrate comprises a lower electrode formed below the second cladding layer.

17. The beam steering mechanism of claim 16, further comprising a cover glass positioned along a top surface of the first cladding layer.

18. The beam steering mechanism of claim 17, further comprising a housing configured to contain the substrate, the first cladding layer, the waveguide core, the second cladding layer, and the cover glass, the housing comprising a beam entrance window aligned with a first end of the waveguide core and a beam exit window aligned with a second end of the waveguide core.

19. A laser printing system, comprising:

a laser configured to produce a beam of light modulated according to image data input to the laser printing system;

a photoreceptor drum comprising a photoconductive layer disposed along an outer peripheral surface of the drum;

a non-mechanical beam steerer configured to steer the modulated light beam in a scanning motion back and forth across the photoconductive layer; and

a printer controller configured to;

organize the image data into pages of information to be printed on recording medium by setting text margins and arranging words and graphics;

process the image data to convert the image data into dot image data;

feed the dot image data one horizontal line at a time to the modulator;

activate the laser and modulator to output a pulsed light beam to the non-mechanical beam steerer, with one pulse of light from the laser for every dot to be printed; and

control an amount of electrical current flowing through the non-mechanical beam steerer to change an effective index of refraction of the non-mechanical beam steerer and steer the light beam in the scanning motion.

20. A non-mechanical optical beam processing device for controlling a laser light beam of a laser printer across a photoreceptor drum of the laser printer, the device comprising:

solid state photonics components for modulating the laser light beam in accordance with image data supplied to the device; and

a non-mechanical beam steering system for receiving the modulated laser light beam, the non-mechanical beam steering system comprising;

a waveguide core for guiding the modulated laser light beam through the non-mechanical beam steering system;

a cladding layer comprising a liquid crystal material disposed adjacent the waveguide core;

a substrate comprising at least one of silicon or an insulator and providing structural support for the waveguide core and the cladding layer; and

a controller configured to control a refractive index of the liquid crystal material of the cladding layer so as to steer the modulated laser light beam propagating through the waveguide core and exiting from the waveguide core in a scanning motion back and forth across the photoreceptor drum of the laser printer.