The following operators can be used to better focus your queries.
( ) , AND, OR, NOT, W/#
? single char wildcard, not at start
* multi char wildcard, not at start
(Cat? OR feline) AND NOT dog?
Cat? W/5 behavior
(Cat? OR feline) AND traits
Cat AND charact*
This guide provides a more detailed description of the syntax that is supported along with examples.
This search box also supports the look-up of an IP.com Digital Signature (also referred to as Fingerprint); enter the 72-, 48-, or 32-character code to retrieve details of the associated file or submission.
Concept Search - What can I type?
For a concept search, you can enter phrases, sentences, or full paragraphs in English. For example, copy and paste the abstract of a patent application or paragraphs from an article.
Concept search eliminates the need for complex Boolean syntax to inform retrieval. Our Semantic Gist engine uses advanced cognitive semantic analysis to extract the meaning of data. This reduces the chances of missing valuable information, that may result from traditional keyword searching.
This article describes a technique for reliably detecting gaps between highly reflective opaque documents in a document feed path using a reflective-type light-emitting diode (LED)/phototransistor sensor.
English (United States)
This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately
77% of the total text.
Page 1 of 2
Gap Sensor for Highly Reflective Opaque Documents
This article describes a technique for reliably detecting gaps between highly
reflective opaque documents in a document feed path using a reflective-type
light-emitting diode (LED)/phototransistor sensor.
Referring to the prior technique shown in Figs. 1a and 1b, sensor 10,
comprising LED 12 and phototransistor 14, is disposed perpendicular to
document feed path 16 in a cavity of bottom paper guide 18 such that light rays
20 from LED 12 are reflected from top reflective paper guide 22 to
phototransistor 14. Consequently, sensor 10 is "off" when light rays 20 are
reflected, as better depicted in Fig. 1b, thereby indicating a gap between opaque
documents (not shown). However, when an opaque document is between
sensor 10 and top reflective paper guide 22, sensor 10 is "on" since light rays 20
are reduced or prevented from impinging on phototransistor 14. However, a
false gap indication occurs when documents having highly reflective surfaces,
e.g., photographic masters, are used since they reflect too much light back to
phototransistor 14, thereby turning sensor 10 "off".
False gap indications are eliminated by the technique shown in Figs. 2a and
2b, where sensor 10 is disposed obliquely to document feed path 16 at an angle
theta and perpendicular to reflective surface 22a of reflective paper guide 22
disposed upward at the angle theta. Thus, with no document in feed path 16,
light rays 20 from LED 12 are reflected fr...