SANWAL P SARRAF
Engineers in Pittsford, NY

6065822, May 23, 2000

Apr 16, 1996

8/633277

Sanwal P. Sarraf - Pittsford NY

Eastman Kodak Company - Rochester NY

B41J 2205, B41J 221, B41J 204

347 15

An ink-jet printer capable of providing a large number of gray levels delivers ink for each pixel through several nozzles for each color, with each nozzle corresponding to a bit of the pixel's image data word. The nozzle corresponding to the least significant bit of the image data word has a capacity to deliver an amount of ink just sufficient to produce 1/256 of the maximum desired density on the media. The second nozzle, corresponding to the next least significant bit of the image data word, has a capacity to deliver twice as much ink as the first nozzle. The third nozzle delivers twice as much ink as the second nozzle (and four times as much as the first nozzle), and so on. The last nozzle delivers 128 times as much ink as the first nozzle. Control of each nozzle is time-sequenced to print each pixel of the image as the printhead scans over the media. The ink is delivered to the image pixel according to the value of the image data word.

5666447, Sep 9, 1997

Nov 21, 1994

8/342958

Chih-Li Chuang - Pittsford NY
Sanwal Prasad Sarraf - Pittsford NY

Eastman Kodak Company - Rochester NY

G02B 626

385 31

A color laser printing apparatus that incorporates the use of fiber optics and a flexible beam-combining device to combine two or more lasers having different wavelengths that correspond to the photosensitivities of the image-receiving media. Use of fiber optics on a flexible beam-combining device allows high flexibility in the placement of components associated with a color laser printing apparatus and making the system easier to align. Because the components of the system no longer require placement in close proximity to one another, certain aspects of the system can be made more compact and any adverse effects of heat generation of the components, such as the lasers, can be greatly reduced.

5825552, Oct 20, 1998

Jun 30, 1997

8/885307

Andrew F. Kurtz - Rochester NY
John R. Debesis - Penfield NY
Sanwal P. Sarraf - Pittsford NY

Eastman Kodak Company - Rochester NY

G02B 2714

359629

A beamsplitter/staggerer (24) for multi-beam laser printers is disclosed. The multi-beam laser printer is comprised of the beamsplitter/staggerer (24), a spatial light modulator (16) having at least two rows of staggered modulator pixel elements (19), and an illumination system comprised of a laser array (10) and an optical system (13) which provides a narrow line of laser light. The beamsplitter/staggerer is adapted to split the narrow line of laser light into at least two parallel lines of light, and to split each of the parallel lines of light into regions, such that substantially all of the light from the illumination system falls onto each of the modulator pixel elements (19) in each of the rows. In one embodiment, the beamsplitter/staggerer comprises a pattern of reflecting areas (26) and transmitting areas (27) wherein a shape of the regions defined by the beamsplitter/staggerer matches a shape of the modulator pixel elements (19).

5808655, Sep 15, 1998

May 12, 1995

8/439746

Daniel D. Haas - Webster NY
Thomas A. Mackin - Hamlin NY
Kurt M. Sanger - Rochester NY
Sanwal P. Sarraf - Pittsford NY

Eastman Kodak Company - Rochester NY

B41J 247, B41J 2435, B41J 235

347234

A multiple-source array for use in thermal printing uses source interleaving to avoid overlapping of the dye-transfer tracks upon the donor material in a single pass. This prevents the formation of artifacts in the image because of thermal interaction among either the sources or printing spots. This also permits the thermal array to be oriented predominantly perpendicular to the first-scan direction so that any arcuate shape of the array causes minimal spacing variations of the scan lines and minimizes spacing variations in focus for laser-thermal printing or document source separation for resistive-head thermal printing. Interleaving also allows multiple printheads to be used even when they have different printing characteristics. The array includes independently addressable printing element data channels and a data distributor allowing interleaving to be accomplished in the printhead. The printhead also includes pixel replication circuitry that allows pixel replication in both the fast and slow scan directions.

5644353, Jul 1, 1997

Jan 4, 1995

8/368561

Sanwal Prasad Sarraf - Pittsford NY

Eastman Kodak Company - Rochester NY

B41J 2435, B41J 248

347224

An apparatus and method are provided for forming a laser-induced thermal dye transfer image. A slide for brings a dye donor and dye receiver into dye transferring proximity, and a laser emits a beam of light toward the donor to image-wise transfer dye to the receiver. The slide, along with the donor therein, is tilted to eliminate intensity noise in the laser caused by light reflecting from the slide and donor back to the laser. By tilting the slide, specular reflections from the dye donor do not intercept optical path and do not propagate along the optical path.

5874981, Feb 23, 1999

Dec 19, 1995

8/574506

Daniel D. Haas - Webster NY
Sanwal P. Sarraf - Pittsford NY

Eastman Kodak Company - Rochester NY

H04N 121

347187

A laser thermal system that uses a dye donor produces a desired relationship of exposure to density by modifying the input current waveform supplied to the exposure source. The modification is a combination of amplitude modulation and pulse width modulation in an imagewise fashion. The efficiency and the speed of image formation is increased by bringing the dye donor temperature near the threshold of dye transfer using a segment of the total current waveform for a very short duration.

5764272, Jun 9, 1998

Apr 24, 1996

8/634598

Sanwal P. Sarraf - Pittsford NY

Eastman Kodak Company - Rochester NY

B41J 247

347246

A laser imager autofocus apparatus, adapted to receive media with an image surface to be scanned, includes a laser and laser optics for producing a beam of light focused at an image plane. A photodiode is associated with the laser and adapted to produce a signal characteristic of the amount of light from the laser that is reflected from the image surface of received media onto the photodiode. Focus of the laser beam on the image surface is adjusted in response to the characteristic signal to maintain close association of the image surface of received media and the image plane of the laser and laser optics. The focus adjusting means may move one or more of the laser, the laser optics, or the image surface of received media. The laser source may be an array of plural laser sources in a line, and the plural laser sources may tilt relative to the image surface of received media.

5646786, Jul 8, 1997

Mar 24, 1995

8/427523

Andrew F. Kurtz - Rochester NY
John R. Debesis - Penfield NY
Sanwal P. Sarraf - Pittsford NY

Eastman Kodak Company - Rochester NY

G02B 2714

359637

An optical system for illuminating a multi-element spatial light modulator from a multi-emitter laser array such that each element of the modulator sees light from all emitters targets the light onto the two or more rows of elements, without putting light into the gap between the rows, and without putting light in the spaces between the elements. The element illumination may match a complex shape of the elements. A beamsplitter/staggerer is adapted to split the line of laser light into plural parallel lines of light, and to split the parallel lines of light into regions such that substantially all of the light from the illumination system falls onto the elements of the rows without impinging between the rows of elements or between the elements in the rows.

5521748, May 28, 1996

Jun 16, 1994

8/261370

Sanwal P. Sarraf - Pittsford NY

Eastman Kodak Company - Rochester NY

G02F 100

359321

A light modulator for use with a laser or laser diode array such that the light from the laser is imaged on a light modulator having a row of light modulating elements, either of the reflectance or transmittance type. The light modulator is imaged onto a light-sensitive material and the image is scanned line by line on the light-sensitive material. Control circuitry is provided to control the relative movement between the light modulator and the light-sensitive material that may be either in planar form or wrapped out the circumference of cylindrical drum.