Reflected light document reading head

Claim 2

A reading head for use in a document scanner or the like having means for conveying documents each containing data response channels along a supporting surface beneath said head, said reading head comprising a source of light remote from a document passing beneath the head, focusing means for directing light from said source into a linear beam and normally onto the surface of a document passing beneath said head, said focusing means including a plurality of optical fibers for forming light from said light source into a linear beam and a lens for focusing the beam of light transmitted by said optical fibers into a narrow linear band, the light from said light source being first focused before being directed into said optical fibers, means for breaking said linear beam of light into a plurality of individual spots of light, one such spot of light for each data response channel, said light source and optical fibers being combined into a unitary illuminator with said illuminator and said lens being movable relative to each other in order that the focal length of the linear beam produced by said lens can be varied, and sensing means for sensing the intensity of light reflected from a document and producing an electronic signal proportional to the light intensity so reflected, said sensing means including sensors located on opposite sides of said linear beam, there being an opposing pair of said sensors for each data response channel of a document being read, each said pair of sensors being connected in parallel and positioned to receive the total light intensity reflected from a single data response area within a particular channel.

Claim 3

The reading head of claim 1 in which said lens is fixed relative to said reading head and said illuminator is movable within said reading head to thereby vary the focal length of the linear beam.

Claim 4

The reading head of claim 1 in which said linear beam is comprised of a plurality of overlapping spots of light, each said spot of light being produced by a cone of light radiating from one of said optical fibers, and said linear beam is broken up into spots of light for each data response area in each data response channel by a member containing a plurality of spaced holes, one hole for each data response area.

Claim 5

The reading head of claim 1 in which said lens and optical fibers are positioned relatively so that the focal point of said light from said lens will be on the document supporting surface beneath the reading head.

Claim 6

A reading head for use in a document scanner or the like having means for conveying documents each containing data response channels along a supporting surface beneath said head, said reading head comprising a source of light remote from a document passing beneath the head, focusing means for directing light from said source into a linear beam and normally onto the surface of a document passing beneath said head, said focusing means including a plurality of optical fibers for forming light from said source into a linear beam and a lens for focusing the beam of light transmitted by said optical fibers into a narrow linear band, the light from said light source being first focused before being directed into said optical fibers, said lens being fixed relative to said reading head, said light source and optical fibers being combined into a unitary illuminator with said illuminator being movable relative to said lens so that the focal length of the linear beam produced by said lens can be varied, and sensing means for sensing the intensity of light reflected from a document and producing an electronic signal proportional to the light intensity so reflected, said sensing means including sensors located on opposite sides of said linear beams, there being an opposing pair of said sensors for each data response channel of a document being read, the sensors in each opposing pair being positioned so as to be directed at a 45* angle to the bottom surface of the reading head and at a 90* angle to each other, each said pair of sensors being connected in parallel and positioned to receive the total light intensity reflected from a single data response area within a particular channel.

Claim 7

A reading head for use in a document scanner or the like having means for conveying documents each containing data response channels along a supporting surface beneath said head, said reading head comprising a source of light remote from a document passing beneath the head, focusing means for directing light from said source into a linear beam and normally onto the surface of a document passing beneath said head, said focusing means including a plurality of optical fibers for forming light from said source into a linear beam and a lens for focusing the beam of light transmitted by said optical fibers into a narrow linear band, the light from said light source being first focused before being directed into said optical fibers, said lens being fixed relative to said reading head, said light source and optical fibers being combined into a unitary illuminator with said illuminator being movable relative to said lens so that the focal length of the linear beam produced by said lens can be varied, and sensing means for sensing the intensity of light reflected from a document and producing an electronic signal proportional to the light intensity so reflected, said sensing means including sensors located on opposite sides of said linear beams, there being an opposing pair of said sensors for each data response channel of a document being read, the sensors in each opposing pair being positioned so as to be directed at a 45* angle to the bottom surface of the reading head and at a 90* angle to each other, each said pair of sensors being connected in parallel and positioned to receive the total light intensity reflected from a single data response area within a particular channel.