Patent US5216258A successfully refreshed from Google Patents.
← Back to Patent Explorer
US5216258A Expired / Lapsed US ⏱️ 0.0 years remaining

Optical density tracking sensor for aligning media

Assignee: Cal Comp Inc
•
Filing: 1992-03-09
•
Granted: 1993-06-01
•
Expires: 2012-03-09
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract In a media transporter which positions media, a method and apparatus is provided for positioning the media for accurate alignment. The method includes the steps of sensing a spatial pattern of densities in the media along a scanned strip, saving the spatial pattern of densities during the initial pass to create a path map from the start position to an end point, comparing subsequently sensed spatial patterns of densities to the path map, and following the path map to repeatedly and accurately position the media at any point along the scanned path. The spatial pattern of densities in the media is sensed by shining a light through the media and sensing the transmitted light intensity.

Inventors

  • 👤 Scott K. McConnell

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 20:10
CPC Classifications
B; B65; B65H; B65H9/00; B65H9/20; G; G03; G03G; G03G15/00; G03G15/65; G03G15/6555; G03G15/6558; G03G15/6567; H; H04; H04N; H04N1/00; H04N1/04; H04N1/047; H04N1/10; H04N2201/00; H04N2201/024; H04N2201/02406; H04N2201/02425; H04N2201/02439; H04N2201/028; H04N2201/03; H04N2201/031; H04N2201/03104; H04N2201/03108; H04N2201/04; H04N2201/047; H04N2201/04701; H04N2201/0471; H04N2201/04729; H04N2201/04731; H04N2201/04734; H04N2201/04737; H04N2201/04753; H04N2201/04756; H04N2201/04789; H04N2201/04791; H04N2201/04793; H04N2201/04794

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 187 words
In media handling apparatus which transports a media having opposed sides, a media position monitoring system for determining the position of media, comprising: a) a light sensor having a light-sensitive surface facing one side of the media, said light sensor producing a signal at an output thereof which is proportional to the intensity of light impinging on said light-sensitive surface; b) a light source facing an opposite side of the media and directing a beam of light through the media onto said light-sensitive surface; c) memory means for holding a sequence of signal values; and d) signal detection and logic means for sampling said output of said light sensor periodically and for sequentially storing values of said output in said memory means while at least a portion of the media is initially moved across said light-sensitive surface so as to create a map of media density values of said portion of said media and for sampling said output of said light sensor periodically and for performing a comparison of the values as sensed while the media is subsequently moved to said values stored in said memory means.
Claim 2
Dependent Claim 187 words
In media handling apparatus which transports a media having opposed sides, a media position monitoring system for determining the position of media, comprising: a) a light sensor having a light-sensitive surface facing one side of the media, said light sensor producing a signal at an output thereof which is proportional to the intensity of light impinging on said light-sensitive surface; b) a light source facing an opposite side of the media and directing a beam of light through the media onto said light-sensitive surface; c) memory means for holding a sequence of signal values; and d) signal detection and logic means for sampling said output of said light sensor periodically and for sequentially storing values of said output in said memory means while at least a portion of the media is initially moved across said light-sensitive surface so as to create a map of media density values of said portion of said media and for sampling said output of said light sensor periodically and for performing a comparison of the values as sensed while the media is subsequently moved to said values stored in said memory means.
Claim 3
Dependent Claim 54 words
The media position monitoring system of claim 1 wherein said apparatus transports said media along a path whereby said portion of said media initially transported across said light sensor comprises a strip and said values of said output stored in said memory means comprise a one-dimensional map of media density values along said strip.
Claim 4
Dependent Claim 45 words
The media position monitoring system of claim 2 wherein said apparatus repeatedly transports said media back and forth along said path between start and stop positions, whereby said signal detection and logic means enable said apparatus to repeatedly return said media to a desired position.
Claim 5
Dependent Claim 46 words
The media position monitoring system of claim 1 wherein said portion of said media initially moved across said light sensitive surface comprises a two-dimensional area, whereby said map comprises a two-dimensional pattern of media density values and media position monitoring system determines a two-dimensional media position.
Claim 6
Dependent Claim 30 words
The media position monitoring system of claim 1 wherein said light-sensitive surface of said light sensor integrates light passing through a cross section of the media along a scanning path.
Claim 7
Dependent Claim 39 words
The media position monitoring system of claim 1 wherein said signal detection and logic means includes an operational amplifier connected to said output of said light sensor and an analog-to-digital converter connected to an output of said operational amplifier.
Claim 8
Dependent Claim 104 words
In media handling apparatus which includes a media transporter which provides motion of said media relative to said apparatus, the improvement comprising: a) means for sensing a spatial pattern of densities in said media as it is transported across said means for sensing; b) means for saving an initial spatial pattern of densities sensed by said means for sensing during an initial transporting of at least a portion of said media across said means for sensing; c) means for comparing said initial spatial pattern of densities with subsequent spatial patterns of densities sensed by said means for sensing during subsequent transporting of said media.
Claim 9
Dependent Claim 104 words
In media handling apparatus which includes a media transporter which provides motion of said media relative to said apparatus, the improvement comprising: a) means for sensing a spatial pattern of densities in said media as it is transported across said means for sensing; b) means for saving an initial spatial pattern of densities sensed by said means for sensing during an initial transporting of at least a portion of said media across said means for sensing; c) means for comparing said initial spatial pattern of densities with subsequent spatial patterns of densities sensed by said means for sensing during subsequent transporting of said media.
Claim 10
Dependent Claim 32 words
The improvement of claim 7 wherein said means for comparing generates from the comparison of said initial and subsequent spatial patterns of densities a signal representative of the position of said media.
Claim 11
Dependent Claim 81 words
The improvement of claim 7 wherein said means for sensing a spatial pattern of densities in the media comprises: a) a light sensor having a light-sensitive surface facing one side of the media, said light sensor producing a signal at an output thereof which is proportional to the intensity of light impinging on said light-sensitive surface; and, b) a light source facing the opposite side of the media and directing a beam of light through the media onto said light-sensitive surface.
Claim 12
Dependent Claim 35 words
The improvement of claim 7 wherein said media transporter transports said media along a path whereby said portion of said media initially transported across said means for sensing comprises a strip extending along said path.
Claim 13
Dependent Claim 26 words
The improvement of claim 10 wherein said light-sensitive surface of said light sensor integrates light passing through a cross section of the media along said strip.
Claim 14
Dependent Claim 50 words
The improvement of claim 7 wherein said media transporter transports said media in two directions, said portion of said media of said initial transporting comprises a two-dimensional area and said initial pattern of densities comprises a two-dimensional pattern, whereby said means for comparing monitors a two-dimensional position of said media.
Claim 15
Dependent Claim 56 words
The improvement of claim 7 wherein said means for saving said spatial pattern of densities during an initial pass and said means for comparing saved ones of said spatial pattern of densities share an operational amplifier connected to said output of said light sensor and an analog-to-digital converter connected to an output of said operational amplifier.
Claim 16
Dependent Claim 164 words
In a media recording apparatus which superimposes successive images on recording media during successive passes of said media through said apparatus, and including a media transporter which returns the recording media to respective start positions prior to said passes of said recording media through said apparatus, a method for accurately positioning said media at each respective start position prior to each one of said passes for accurate alignment of the superimposed images, comprising: a) sensing a spatial pattern of densities in the recording media along a scanned strip; b) saving the spatial pattern of densities during the initial pass to create a path map of the recording media between a start position and an end position; c) comparing saved ones of the spatial pattern of densities to spatial patterns of densities sensed during subsequent passes of the media in either one of forward and reverse directions; and, d) following the path map to repeatedly and accurately position the recording media before each subsequent pass.
Claim 17
Dependent Claim 164 words
In a media recording apparatus which superimposes successive images on recording media during successive passes of said media through said apparatus, and including a media transporter which returns the recording media to respective start positions prior to said passes of said recording media through said apparatus, a method for accurately positioning said media at each respective start position prior to each one of said passes for accurate alignment of the superimposed images, comprising: a) sensing a spatial pattern of densities in the recording media along a scanned strip; b) saving the spatial pattern of densities during the initial pass to create a path map of the recording media between a start position and an end position; c) comparing saved ones of the spatial pattern of densities to spatial patterns of densities sensed during subsequent passes of the media in either one of forward and reverse directions; and, d) following the path map to repeatedly and accurately position the recording media before each subsequent pass.
Claim 18
Dependent Claim 76 words
The method of claim 14 wherein said step of sensing a spatial pattern of densities in the recording media along a scanned strip comprises the steps of: a) transmitting light through the recording media; b) sensing the amount of light transmitted through the recording media at a plurality of successive sites along the scanned strip; and c) generating a signal for each of the sites reflecting the amount of light transmitted through the recording media thereat.

References Cited (Backward Citations)

US4723072A Cited
US5013156A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-05-31 1996-11-30 1997-06-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-05-31 2000-11-30 2001-06-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-05-31 2004-11-30 2005-06-01 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag