System for monitoring and controlling electrophotographic toner operation

Claim 2

Method for monitoring and controlling electrographic toner operation, in a copier having a sensor (48) for producing an output signal indicative of the reflectivity of the photoconductor thereof and means for establishing a test patch (70) on the photoconductor, characterized in that it comprises the steps of - sampling the output of said sensor (48) a plurality of discrete times as said patch moves past said sensor, - storing signals indicative of the result of each of the discrete samples, and - averaging the stored signals for producing a signal representative of the reflectivity of said patch, whereby the average signal is usable for determining the quality of operation of the copier.

Claim 3

Method in accordance with claim 1 which includes the step of applying toner to said test patch prior to said sampling step.

Claim 4

Method in accordance with claim 1 which includes the further steps of - applying toner to a test patch, and - repeating said sampling, storing and averaging steps relative to said toned test patch whereby the two resultant average signals represent the reflectivity difference between untoned and toned photoconductor test patches.

Claim 5

Method in accordance with claim 3 which includes the further steps of - comparing the reflectivity difference between the untoned and toned test patch average signals with at least one predetermined difference level, and - adjusting the rate of toner replenishment in the developer of said copier in accordance with the result of said comparing step.

Claim 6

Method in accordance with claim 4 which includes the further steps of - determining that a predetermined number of said adjusting steps has occurred with common results from said comparing step, and - indicating that said copier requires attention in response to said determining step.

Claim 7

Device for monitoring and controlling electrographic toner operation in an electrophotographic machine having a plurality of electrophotographic processing elements arranged relative to a moving photoconductor (20) with said elements including a developer (33), photoconductor charging and discharging devices (34, 35) and a sensor (48) for producing a signal indicative of the reflectance of said photoconductor as said photoconductor moves past said sensor, and means for establishing toned and untoned patches on said photoconductor, characterized in that it comprises - a digital-to-analog signal converter (56), - a comparator circuit (58) coupled to compare the reflectance sensor signal (55) with the output (57) of said converter and for providing a binary signal as an output to indicate the results of the comparison, and - a digital data processing unit (52) having an output coupled for providing the input to said converter and having an input coupled for receiving said comparator circuit binary signal output, said data processing unit including - means for producing a plurality of operations of said comparator circuit as each patch on the photoconductor passes the sensor, - means for storing the results of said plurality of comparator circuit operations, and - means averaging said stored results for producing output signals indicative thereof.

Claim 8

Device for monitoring and controlling electrographic toner operation in an electrophotographic machine having a plurality of electrophotographic processing elements arranged relative to a moving photoconductor (20) with said elements including a developer (33), photoconductor charging and discharging devices (34, 35) and a sensor (48) for producing a signal indicative of the reflectance of said photoconductor as said photoconductor moves past said sensor, and means for establishing toned and untoned patches on said photoconductor, characterized in that it comprises - a digital-to-analog signal converter (56), - a comparator circuit (58) coupled to compare the reflectance sensor signal (55) with the output (57) of said converter and for providing a binary signal as an output to indicate the results of the comparison, and - a digital data processing unit (52) having an output coupled for providing the input to said converter and having an input coupled for receiving said comparator circuit binary signal output, said data processing unit including - means for producing a plurality of operations of said comparator circuit as each patch on the photoconductor passes the sensor, - means for storing the results of said plurality of comparator circuit operations, and - means averaging said stored results for producing output signals indicative thereof.

Claim 9

Device in accordance with claim 6 which further includes a second digital data processing unit (50) comprising - means for generating signals directing said first mentioned digital data processing unit to perform a sequence of said comparator circuit operations, - means for receiving said averaging means output signals, and - means responsive to differences of said received average signals relative to predetermined standards for initiating corrective action by the electrophotographic machine.

Claim 10

Device in accordance with claim 7 wherein said corrective action initiating means includes means for causing a change in the rate of toner replenishment to the developer element.

Claim 11

Electrophotographic copier having a movable photoconductor (20) and an original document scanning window (15) with a housing (19) movable into and out of overlying relationship with said window wherein said housing contains means cooperating with said copier for erasing said photoconductor when said housing is in said window overlying relationship, characterized in that it comprises

Claim 12

Electrophotographic copier having a movable photoconductor (20) and an original document scanning window (15) with a housing (19) movable into and out of overlying relationship with said window wherein said housing contains means cooperating with said copier for erasing said photoconductor when said housing is in said window overlying relationship, characterized in that it comprises

Claim 13

- means selectively operable for acquiring data on the reflectivity of at least one test patch on said photoconductor, - means sensing the relationship of said housing relative to said window, and - means responsive to said sensing means for disabling said data acquiring means except when said housing is in said window overlying relationship.

Claim 14

- means selectively operable for acquiring data on the reflectivity of at least one test patch on said photoconductor, - means sensing the relationship of said housing relative to said window, and - means responsive to said sensing means for disabling said data acquiring means except when said housing is in said window overlying relationship.

Claim 15

Copier in accordance with claim 9 which includes means sensing (45) the level of toner material available for feeding from a reservoir (40) into a developer sump (42) further comprising - means connected to said reservoir sensing means for indicating a low level of toner in said reservoir, and - means responsive to an indication from said housing relation sensing means that said housing is not in said window overlying relationship and to said toner reservoir low level indicating means for preventing operation of said copier.