Print dryer heater control
First Claim
1. A method for controlling temperature of a print dryer, comprising:
- applying full power to a heater of the print dryer;
repetitively measuring and storing a series of temperatures of the print dryer until a target temperature for the print dryer is exceeded;
turning off the heater after the target temperature is exceeded;
calculating from the stored temperatures a rate of temperature change at a time when the target temperature was exceeded;
determining, using the rate, an initial heater duty cycle defining an initial heater power, wherein the determining comprises converting the rate of temperature change into the initial heater duty cycle according to a piecewise-continuous function associated with the target temperature, where the initial heater duty cycle is negatively proportional to the rate below a given rate and constant above the given rate; and
performing proportional-integral-derivative (PID) control of the heater power, beginning with the initial heater duty cycle, to maintain the print dryer temperature at the target temperature within a predefined accuracy.
1 Assignment
0 Petitions
Accused Products
Abstract
In one example, a method for controlling temperature of a print dryer. High power is applied to a heater of the print dryer. A series of temperatures of the print dryer are periodically measured and stored until a target temperature for the print dryer is exceeded. Low power is applied to the heater after the target temperature is exceeded. A rate of temperature change at a time when the target temperature was exceeded is calculated from the stored temperatures. Using the rate, an initial heater duty cycle defining an initial heater power determined. PID control of the heater power is performed, beginning with the initial heater duty cycle, to maintain the print dryer temperature at the target temperature within a predefined accuracy.
-
Citations
13 Claims
-
1. A method for controlling temperature of a print dryer, comprising:
-
applying full power to a heater of the print dryer; repetitively measuring and storing a series of temperatures of the print dryer until a target temperature for the print dryer is exceeded; turning off the heater after the target temperature is exceeded; calculating from the stored temperatures a rate of temperature change at a time when the target temperature was exceeded; determining, using the rate, an initial heater duty cycle defining an initial heater power, wherein the determining comprises converting the rate of temperature change into the initial heater duty cycle according to a piecewise-continuous function associated with the target temperature, where the initial heater duty cycle is negatively proportional to the rate below a given rate and constant above the given rate; and performing proportional-integral-derivative (PID) control of the heater power, beginning with the initial heater duty cycle, to maintain the print dryer temperature at the target temperature within a predefined accuracy. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A non-transitory computer-readable storage medium having an executable program stored thereon, wherein the program instructs a processor to:
-
apply a high duty cycle to turn on a heater of a print dryer at high power; repetitively measure and record a temperature of the print dryer while heating at the high power; apply a low duty cycle to turn off the heater when the print dryer exceeds a target temperature; calculate from the recorded temperatures a rate of temperature change across the target temperature; determine an initial heater duty cycle corresponding to the rate, wherein the determining comprises converting the rate of temperature chance into the initial heater duty cycle according to a piecewise-continuous function associated with the target temperature, where the initial heater duty cycle is negatively proportional to the rate below a given rate and constant above the given rate, and perform proportional-integral-derivative (PID) control of the heater beginning with the initial heater duty cycle to maintain the print dryer at the target temperature within a predefined accuracy. - View Dependent Claims (11, 12, 13)
-
Specification