Method and apparatus for copier quality monitoring and control
AssigneeInternational Business Machines Corporation
InventorLarry M. Ernst
Life of this patent
Estimating the term…
Abstract
Data correlated to the light reflectance of a maximum toned area and a minimum toned area is recorded to establish standards for monitoring and controlling subsequent copier operation. A test pattern is imaged onto the photoconductor by controlled illumination levels in a series of steps with the detection of light reflectance from that test pattern being subsequently compared to establish the maximum black and maximum white criteria for storage. Light reflected from cleaned photoconductor areas and subsequently established toner patches then are used to compare against the original test pattern reflectance data. Toner replenishment, controls and machine function monitoring (e.g.: white copy background, developer operation, etc.) are based on these recorded standards from the test pattern.
Claims10
The method of establishing toner level standards for a copier which has a moving photoconductor, means for charging said photoconductor for receiving an electrostatic image, an illumination lamp arranged for illuminating said photoconductor, a developer for applying toner to said photoconductor and means for measuring light reflected from said photoconductor comprising the steps of:
- charging said photoconductor for accepting images;
- controlling said lamp and said developer for selectively creating sequential areas on said photoconductor ranging from an area of maximum toner application to an area of minimum toner application;
- sensing the output of said measuring means where said output indicates light reflected from said photoconductor sequential areas as they pass said measuring means;
- and
- storing signals corresponding to said measuring means output correlated to said sequential areas on said photoconductor,
- whereby operation of said copier is at least partially determinable by subsequent comparisons of said measuring means output with said stored signals.
In an apparatus for monitoring operation of a copier having a moving photoconductor, means for charging said photoconductor for electrostatic imaging, a lamp for illuminating said photoconductor, a developer for applying toner to said photoconductor and means responsive to light reflected from said photoconductor for producing an output signal correlated to the magnitude of said reflected light, an improvement comprising:
- a comparator having said reflected light means output coupled as one input thereto and having an output terminal;
- a power source responsive to an input for applying selectable power levels to said lamp;
- and
- a controller including:
- (a) means for producing first and second output signals of selectable magnitudes with said first signal output coupled as said power source input and said second signal output coupled as a second input to said comparator;
- (b) means for storing data correlated to signals at said comparator means output terminal;
- and
- (c) a sequencer having:
- (i) means energizing said first output signal for causing said lamp to produce light in a sequence between a maximum intensity and an off condition so as to place an image test pattern on said photoconductor;
- (ii) means operable in response to said output signal of said reflected light responsive means caused by said photoconductor test pattern for varying said second output signal until said comparator output indicates a favorable comparison result;
- and
- (iii) means enabling said storing means to store data correlated to at least the maximum and minimum levels of said favorable comparison results.
Dependencies are inferred from the claim text.