Apparatus and method for measuring a dimension of an object
First Claim
1. Apparatus for measuring a dimension of an object comprising:
- a first element which is adjustable to different positions to contact a portion of the object,a second element which is stationary relative to the object, wherein one of the first and second elements includes an electro-optical sensor for transmitting and receiving an optical signal and the other of the first and second elements includes a tappered arm having a length, wherein a surface of the arm which is sloped relative to the electro-optical sensor provides a reflective surface, the reflective surface facing and being spaced from said electro-optical sensor,wherein the spacing between said reflective surface and said electro-optical sensor is variable according to different adjustment positions of the first element such that the strength of an optical signal reflected from the reflective surface and received by the sensor relative to a transmitted optical signal is correspondingly variable,whereby the electro-optical sensor provides an electrical signal which is a measure of a dimension of the object when the first element is adjusted to a position in contact with said portion thereof.
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Accused Products
Abstract
A method and apparatus for measuring a dimension of an object which utilizes a reflective photosensor and a facing reflective surface, wherein the spacing between the sensor and the reflective surface is varied depending on the dimension to be measured. The preferred application of the invention is in a sheet feeder for a printer wherein the invention provides an electrical signal indicative of the size of sheets in the sheet feeder. The electrical signal may be used to control a printing function. The sheet feeder (10) includes a base (14) having a paper guide (18) slideably mounted thereon. The guide (18) carries a tapered arm (26) which includes a reflective surface (28). A reflective photosensor (30) is fixedly mounted on the base opposite the reflective surface (28) such that the variable distance between the sensor (30) and the surface (28) as the paper guide (18) is adjusted gives a correspondingly variable electrical output from the sensor. When the sensor (30) is adjusted against the edge of a stack of sheets, the sensor'"'"'s output represents a dimension of those sheets.
10 Citations
14 Claims
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1. Apparatus for measuring a dimension of an object comprising:
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a first element which is adjustable to different positions to contact a portion of the object, a second element which is stationary relative to the object, wherein one of the first and second elements includes an electro-optical sensor for transmitting and receiving an optical signal and the other of the first and second elements includes a tappered arm having a length, wherein a surface of the arm which is sloped relative to the electro-optical sensor provides a reflective surface, the reflective surface facing and being spaced from said electro-optical sensor, wherein the spacing between said reflective surface and said electro-optical sensor is variable according to different adjustment positions of the first element such that the strength of an optical signal reflected from the reflective surface and received by the sensor relative to a transmitted optical signal is correspondingly variable, whereby the electro-optical sensor provides an electrical signal which is a measure of a dimension of the object when the first element is adjusted to a position in contact with said portion thereof. - View Dependent Claims (2, 3, 4)
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5. Apparatus for measuring a dimension of an object comprising:
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a first element which is adjustable to different positions to contact a portion of the object, a second element which is stationary relative to the object, wherein one of the first and second elements includes an electro-optical sensor for transmitting and receiving an optical signal and the other of the first and second elements includes an arm having a length, wherein the arm is stepped along its length to define reflective surface sections wherein each section faces and is variably spaced from the electro-optical sensor according to different adjustment positions of the first element such that the strength of an optical signal reflected from the reflective surface sections and received by the sensor relative to a transmitted optical signal is correspondingly variable, whereby the electro-optical sensor provides an electrical signal which is a measure of a dimension of the object when the first element is adjusted to a position in contact with said portion thereof.
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6. A sheet feeder for a printer comprising,
a base for supporting a sheet for passage through the printer, a first element associated with the base and which is adjustable to different positions to contact an edge of the sheet, a second element associated with the base and which is stationary relative thereto, wherein one of the first and second elements includes an electro-optical sensor for transmitting and receiving an optical signal and the other of the first and second elements includes a reflective surface which faces and is spaced from said electro-optical sensor, wherein the spacing between said reflective surface and said electro-optical sensor is variable according to different adjustment positions of the first element such that the strength of an optical signal reflected from the reflective surface and received by the sensor relative to a transmitted optical signal is correspondingly variable, whereby the electro-optical sensor provides an electrical signal which represents a dimension of the sheet on the base when the first element is adjusted to a position in contact with an edge of said sheet.
Specification