Patent US5038158A successfully refreshed from Google Patents.
← Back to Patent Explorer
US5038158A Expired / Lapsed US ⏱️ 0.0 years remaining

Electromagnetic gray scale printer

Assignee: Applied Resources Inc
•
Filing: 1989-11-13
•
Granted: 1991-08-06
•
Expires: 2009-11-13
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A gray scale image poster printer reproduces a digitally stored bit map image on a printer using an electrostatic and magnetic toner to generate gray scale images by expanding each line of the original stored image into a plurality of subpixels along the horizontal scanning lines and by synchronizing the printing of the subpixel lines with a changing magnetic field that changes the amount of toner deposited in each subpixel.

Inventors

  • 👤 Robert W. Ayers
  • 👤 Richard M. Kerbel

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 09:46
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40087; H04N1/024; H04N1/032

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 76 words
A process for printing an image comprising: (a) transmitting digital data to a printer that constructs images from digital data; (b) sensing the strength of a changing, recurring magnetic field adjacent to a print medium; and (c) periodically synchronizing the printing of a line on said medium with changes in the magnetic field as sensed in step (b), by responding to periodic occurrences of a predetermined strength of the changing magnetic field to effect said synchronization.
Claim 2
Dependent Claim 76 words
A process for printing an image comprising: (a) transmitting digital data to a printer that constructs images from digital data; (b) sensing the strength of a changing, recurring magnetic field adjacent to a print medium; and (c) periodically synchronizing the printing of a line on said medium with changes in the magnetic field as sensed in step (b), by responding to periodic occurrences of a predetermined strength of the changing magnetic field to effect said synchronization.
Claim 3
Dependent Claim 45 words
The process as set forth in claim 1 further comprising the step of creating an expanded image in which each line of the original image is divided into a plurality of sublines to create a set of sublines for each line of the original image.
Claim 4
Dependent Claim 27 words
The process as set forth in claim 2 wherein said synchronizing step (c) further comprises synchronizing printing once for the printing of each said set of sublines.
Claim 5
Dependent Claim 35 words
The process as set forth in claim 1 wherein the changing magnetic field is bipolar and said synchronizing step (c) further includes responding to the polarity of the changing magnetic field to synchronize said printing.
Claim 6
Dependent Claim 26 words
The process as set forth in claim 1 further comprising the step of dispersing a toner adjacent said print medium in response to said magnetic field.
Claim 7
Independent Claim 122 words
An apparatus for printing images comprising: a poster printer having a display sheet, means for receiving a digital image, and means for printing an image on said display sheet, a computer and means for expanding each pixel of said digital image into a plurality of subpixels to create an expanded image, means for mapping the color tone of each pixel of said digital image into the corresponding subpixels of said expanded image, and said printing means comprising an agitator roller having a plurality of lengthwise projecting magnetized splines of alternating polarity for dispersing a toner and means for coordinating the disposition of toner on said display sheet during printing with the changes in the magnetic field caused by rotating said agitator roller.
Claim 8
Independent Claim 122 words
An apparatus for printing images comprising: a poster printer having a display sheet, means for receiving a digital image, and means for printing an image on said display sheet, a computer and means for expanding each pixel of said digital image into a plurality of subpixels to create an expanded image, means for mapping the color tone of each pixel of said digital image into the corresponding subpixels of said expanded image, and said printing means comprising an agitator roller having a plurality of lengthwise projecting magnetized splines of alternating polarity for dispersing a toner and means for coordinating the disposition of toner on said display sheet during printing with the changes in the magnetic field caused by rotating said agitator roller.
Claim 9
Independent Claim 110 words
An apparatus for printing images comprising: a poster printer having a display sheet, means for receiving a digital image, and means for printing an image on said display sheet, a computer and means for expanding said pixel of said digital image into a plurality of subpixels to create an expanded image, means for mapping the color tone of each pixel of said digital image into the corresponding subpixels of said expanded image, and said printing means comprising means for producing a changing, recurring magnetic field for dispersing a toner and means for coordinating the disposition of toner on said display sheet during printing with the changes in said magnetic field.
Claim 10
Independent Claim 110 words
An apparatus for printing images comprising: a poster printer having a display sheet, means for receiving a digital image, and means for printing an image on said display sheet, a computer and means for expanding said pixel of said digital image into a plurality of subpixels to create an expanded image, means for mapping the color tone of each pixel of said digital image into the corresponding subpixels of said expanded image, and said printing means comprising means for producing a changing, recurring magnetic field for dispersing a toner and means for coordinating the disposition of toner on said display sheet during printing with the changes in said magnetic field.
Claim 11
Dependent Claim 16 words
An apparatus in accordance with claim 7 further comprising means for maintaining any desired aspect ratio.
Claim 12
Dependent Claim 16 words
An apparatus in accordance with claim 7 wherein said coordinating means includes a Hall effect sensor.

References Cited (Backward Citations)

US4357901A Cited
US4760410A Cited
US4814886A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-08-05 1995-02-04 1995-08-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-08-05 1999-02-04 1999-08-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-08-05 2003-02-04 2003-08-06 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag