3.6.5Heat Storage Coefficient
A difference between an actual rise in temperature of the thermal head due to the head activation and the detected temperature by the thermistor occurs in the high speed printing.
Therefore, a correction of the activation pulse through the simulation of a rise in thermal head temperature is needed.
A correction may not be needed when the print ratio is low. Set “1” as the heat storage coefficient at this time.
The heat storage coefficient is calculated with the manner as follows:
(1) Prepare the heat storage software counters for each block to simulate the heat storage.
(a)Heat storage due to the head activation
The heat storage counter counts up in each print cycle as follows.
64⋅N
D= B
When D>50, D=50
T’=T+D
T:Heat storage counter value
N:Number of the activated dots
B:Total dot number of each block
(b)Radiation due to time
The heat storage counter value is multiplied by the radiation coefficient in each 1 msec.
T’=T⋅K
K:Radiation coefficient 0.997
(2)Calculate the heat storage coefficient with the following equation, using the heat storage counter.
Equation (6):
D=1- T 74981