Method and apparatus employing a linear array IR region radiation devices for locating the position of conveyor transported products

Apparatus for locating an edge of material, comprising:

• an emitter array of discrete semiconductor junction devices located a select distance from one side of said material and extending partially outwardly from said edge, each said device being within a photoemitter configuring circuit providing for the application of current thereto to effect an emission of radiation at a wavelength within the infra-red region of the electromagnetic spectrum;
• a receiver located a stand-off distance from the opposite side of said material and including a said semiconductor junction device within a photoreceptor configured circuit positioned for response to said radiation which transitions between conditions of attenuation and non-attenuation in the vicinity of said edge to derive output signals corresponding with the amplitudes of said emitted radiation;
• a drive network responsive to control inputs for applying said current to said discrete junction devices;
• and
• a control circuit deriving said control inputs at a predetermined frequency and responsive to said receiver output signals for deriving an output corresponding with the location of said edge.

Apparatus for detecting the presence of a marker opening within a region of a substantially continuous sheet of material moving along a process path, comprising:

• an emitter array of discrete semiconductor junction devices located a distance from one side of said sheet of material at said region, each said device being a component of a photoemitter configuring circuit providing for the application of current thereto to effect emission of radiation at a given wavelength within the infra-red region of the electromagnetic spectrum;
• a receiver located a stand-off distance from the opposite side of said material and including a said semiconductor junction device as a component within a photoreceptor configured circuit, said receiver being positioned for response to said radiation transmitted through said marker opening to derive output signals;
• a drive network responsive to control inputs for applying said current to said semiconductor junction devices of said emitter array;
• a control circuit for deriving said control inputs at a predetermined frequency and responsive to said receiver output signals for deriving an output detecting said opening.

Apparatus for locating an edge of material, comprising:

• an array of discrete radiation emitting devices, said array having a first row of a plurality of mutually spaced apart said devices commencing with a first said device, and having a second row of a plurality of spaced apart said devices commencing with a first said device, said second row of said devices being offset from said first row of said devices a predetermined distance, said array being located a select distance from one side of said material and extending partially outwardly from said edge, each said device being responsive to the application of a value of current thereto to emit said radiation;
• a radiation responsive receiver located a predetermined stand-off distance from the opposite side of said material and positioned for response to said radiation emitted by said devices which transitions between conditions of attenuation and non-attenuation in the vicinity of said edge to derive output signals corresponding with the amplitude thereof;
• a drive network responsive to control inputs for applying said current to said discrete radiation emitting devices;
• and
• a control circuit for deriving said control inputs to apply said current to said discrete radiation devices which effects the application of current to a said device of said second row next in sequence following the application of current to an adjacently disposed device of said first row.

In a system for locating the edge of material under movement across a process location, wherein an array of radiation emitting devices are positioned from first to last along a scan path at an operational location spaced from said material and extending outwardly from said edge, said devices being energized in response to the application of drive current thereto to emit radiation of given intensity, and a receiver is spaced from the opposite side of said material an operational distance from said array of devices and provides output signals of amplitude varying with said intensity of emitted radiation modulated with respect to the attenuation thereof by said material, the method for optimizing the radiation emission performance of said devices, comprising the steps of:

• positioning said receiver at said operational distance from said array at the situs of said process location without the presence of said material;
• providing memory responsive to a write mode input to record drive current values and to a read mode to provide memory retained drive current values when addressed at address locations corresponding with said first-to-last device positions;
• providing an analog-to-digital converter responsive to an analog input to derive said drive current values;
• providing a drive network responsive to said drive current values to derive said drive currents for energizing said devices;
• determining an initial value for said drive current;
• applying said initial value as a said analog input to said analog-to-digital converter to derive a corresponding initial drive current value and deriving therefrom an initial value of drive current by said drive network to initially energize each said emitting device and deriving a said output signal with said receiver corresponding with the intensity of emitted radiation of each when detected by said receiver;
• summing said derived output signals and dividing said sum by the number of said devices to provide an average value thereof;
• test energizing each said device by applying to said analog-to-digital converter a said analog input representing a value for said drive current which has been adjusted by an incremental value effecting a convergence of the value of output signals representing said adjusted drive current with said average value;
• deriving a said output signal with said receiver corresponding with the intensity of radiation received from each said device;
• and
• reiterating said steps of test energizing each said device, and deriving a said output signal until a set of final values of drive current are produced represneting a select convergence between said derived output signals and an average value thereof.