JPH0299338A - Method for controlling temperature of heater of ink jet printer - Google Patents

Abstract

PURPOSE:To reduce the load given to a power supply part and to enhance efficiency by controlling the temp. of a heater so as to change over the same to temp. suitable for printing duty and giving only the quantity of heat necessary for drying ink to the heater. CONSTITUTION:The data A, B corresponding to printing duties divided into some levels are given to a heater temp. setting circuit 5 and transistors Tr1, Tr2 are turned ON/OFF on the basis of said data and the voltage V+ divided by resistors R2, R3, R4, R5 is given to the (+) input of the comparator of a temp. control circuit 3. The comparator successively compares the voltage V- showing the temp. of the heater with the voltage V+ showing the set temp. of the heater and, at the time of V-<V+, an H-level showing driving is outputted to a heater driving part 6. At the time of V->V+, an L-level showing the stop of driving is outputted. Since a current is supplied to the heater 1 and stopped corresponding to the levels H, L of heater driving data C in the heater driving part 6, the temp. of the heater is controlled to set temp. and the ink adhered to a recording medium 7 is dried by the quantity of heat corresponding to the amount of the ink.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for controlling the temperature of an ink drying heater in a vintage inkjet printer.

[Prior Art] In an inkjet printer, liquid ink is attached to a recording medium, so the drying time of the ink is an important factor in print quality and handling of the recording medium.

In conventional inkjet printers that use a heater to dry ink, the heater temperature is
That is, the temperature is generally controlled to be constant regardless of the amount of ink deposited on the recording medium.

[Problems to be Solved by the Invention] In such conventional examples, there are cases where the output to the printer is a pattern that has a small amount of ink such as characters and is easy to dry, and a pattern that has a large amount of ink and is difficult to dry, such as a graphic output. Because the heater temperature is kept constant without distinguishing between drying conditions, the heater emits more heat than necessary, resulting in poor efficiency, or the heater is not effective because it does not provide enough heat for drying. The problem is that we don't get enough.

The present invention solves the above problem, and its purpose is to switch and control the heater temperature to a temperature suitable for the printing duty, and to supply the heater with the amount of heat necessary to dry the ink, thereby increasing the power supply. The aim is to reduce the load on the parts and improve efficiency.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention uses a printing duty detection unit that detects the printing duty and a duty-based control temperature setting circuit to control the printing according to the detected duty. The control temperature setting circuit sets the control temperature of the heater in multiple stages based on the data output from the duty detection section, and passes the setting data to the temperature control circuit.

[Function] The print duty obtained from the print data in the print duty detection section is divided into several levels and input to the control temperature setting circuit as data corresponding to the levels. The corresponding heater set temperature data is output to the temperature control circuit.The temperature control circuit successively compares the heater set temperature data and the heater temperature data output from the heater temperature detection element, and outputs a drive signal to the heater drive section. .

In this way, the heater temperature is controlled to a temperature that generates the amount of heat necessary to dry the ink according to the amount of ink that adheres to the recording medium, which is expected to reduce the load on the power supply and improve efficiency. Possible [Embodiment] The illustrated embodiment will be described below.

In FIG. 1, 1 is a heater, to which a heater temperature detection element 2 is attached. In this embodiment, a thermistor is used as the heater temperature detection element 2. The heater temperature detection element 2 is connected to a temperature control circuit 5. The temperature control circuit 6 consists of a circuit as shown in the figure.
A voltage divided by the heater temperature detection element 2 and the resistor R1 is applied to the comparator. 4 is a print duty detection section. The printer's OPU or the like processes the print data, and provides data A and B corresponding to the print duty divided into several levels to the control temperature setting circuit 5. The control temperature setting circuit 5 uses this data to set the transistors Tr1. Tr2 is 0N10FF and resistance R
2, R5, R4° The voltage v0 divided by R5 is applied to one input of the comparator of the temperature control circuit 6. In this embodiment, the voltage V+ based on data A and H can be set in four stages as shown in FIG. In the temperature control circuit 6, a comparator successively compares a voltage V- indicating the heater temperature with a voltage V0 indicating the heater set temperature, and outputs an H level indicating drive as heater drive data 0 when V-(V+).

Further, when the voltage is V-, )V+, the heater drive data C is outputted as L level indicating drive stop.

In the heater drive unit 6, the level H of heater drive data 0
, L to supply or stop current to the heater 1, the heater temperature is controlled to the temperature set in the heater temperature setting circuit 5, and the ink attached to the recording medium 7 is dried with an amount of heat corresponding to the amount of ink. Ru.

Next, the operation of the embodiment will be explained based on the waveform diagram in FIG.

When the voltage V- is lower than the voltage v+i set by data A and B, that is, when the heater temperature is lower than the heater setting temperature, the heater drive data C becomes H level and the heater drive circuit 6 is in the ON state. Supply current to heater 1. Eventually, the heater temperature rises and becomes higher than the heater set temperature (as the magnitude relationship between voltage V+1 and voltage V- is reversed, the heater drive data C is reversed and the heater drive circuit 6 is turned off. is not supplied, the heater temperature decreases (and the voltage - becomes lower than V+1), and the heater drive data C becomes H level again and the heater drive circuit 6 is turned on.In this way, the heater temperature decreases When a different printing duty controlled to the set temperature is detected,
The data A and B change, and the voltage V+ changes accordingly (here it is V+2), so that the heater temperature is controlled to a different heater set temperature.

By determining the voltage V+ indicating the heater set temperature for the printing duty as described above, it becomes possible to control the heater temperature in accordance with the printing duty by detecting the printing duty and outputting the corresponding data.

[Effects of the Invention] As described above, according to the heater temperature control method according to the present invention, the amount of heat necessary and sufficient to dry the ink attached to the recording medium is supplied from the heater according to the print date. Therefore, when the duty is low, the countless amount of heat generated from the heater is suppressed, and when the duty is high, a sufficient amount of heat is obtained, which has the effect of improving current efficiency.

Furthermore, compared to conventional methods, the load on the power supply unit is reduced.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of an embodiment of the present invention, and Fig. 2 is a comparator input voltage according to data A and B indicating printing duty.
FIG. 3 is a waveform diagram showing the relationship between data A and B, heater drive data C, and heater temperature. 1...Heater 2...Heater temperature detection Utsuko 3...
...Temperature control circuit 4...Print duty detection section 5...
...Heater temperature setting circuit 6...
Heater drive unit 7...Recording medium R1-R7...Resistance Tr1. Tr2...Transistor Figure 2 and above Applicant Seiko Epson Co., Ltd. Agent Patent attorney Kizobe Suzuki (and 1 other person) Figure 3

Claims (1)

[Claims] In an inkjet printer having a heater that dries ink attached to a recording medium, a print duty detection section that detects dot density of print data, and a control temperature setting that switches the control temperature of the heater based on the output from the print duty detection section. a heater temperature detection element that detects the temperature of the heater, a temperature control circuit that controls the temperature of the heater based on the output of the control temperature setting circuit, and a heater drive section, and A method for controlling a heater temperature of an inkjet printer, comprising controlling the temperature of the heater by changing it in multiple stages.