JPH03151239A - Temperature compensating method for ink-jet recorder - Google Patents

Abstract

PURPOSE:To obtain a uniform recording quality by a method wherein the ink quantities discharged for recording on divided areas for heating elements are individually detected, and the heating elements are controlled so that the divided areas on a recording medium are respectively heated up to a temperature suitable for drying ink adhered on the divided areas. CONSTITUTION:A duty detector 5 detects density of ink recorded on areas which receive heat generated by heating elements 3a-3d, and outputs duty level signal 6a-6d. Temperature control circuits 7a-7d receive the duty level signals 6a-6d and resistance values of temperature detecting elements 4a-4d, and output heating element control signals 8a-8d to heating element driving circuits 9a-9d. The heating element driving circuits 9a-9d receive the heating element control signals 8a-8d from the temperature control circuits 7a-7d, and supply electric currents to the heating elements 3a-3d. And, for example, when the temperatures of the heating element 3a is lower than the ink drying temperature T1, electric current is supplied to the heating element 3a, and when it is higher, the electric current supply is stopped to reduce the temperature. Thereby, the uniform recording quality can be achieved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a temperature compensation system for an inkjet recording device that performs recording by ejecting ink droplets.
Small i1 The drying time of the ink in inkjet recording changes greatly with temperature changes [,,'X, which affects the infiltration into the recording medium after recording and the abrasion resistance, and causes a decrease in recording quality. On the other hand, the operating temperature of inkjet recording devices generally ranges over a wide range from 0'C to 40'C, so in order to keep the ink drying time constant in this range, a heating element is required to heat the ink on the recording medium. In order to keep the ink drying time constant over the entire recording area of the recording medium, the size of the heating element must be larger than the entire width of the recording medium.9 An increase in the power required for heating is avoided. do not have.

Furthermore, since the amount of ink on the recording medium depending on the recording density always changes depending on the pattern of the recording data, in order to guarantee the ink drying time, it is necessary to set the heating value for the maximum ink I in the recording area. When the recording density is extremely low and the amount of ink is small, the drying time becomes short and the ink permeation into the recording medium changes, making it impossible to maintain uniform recording quality.

[Problems to be Solved by the Invention] The present invention eliminates the above-mentioned drawbacks and proposes a temperature compensation method for an Infusiera 1 recording device that has uniform recording quality.

[Means to solve the problem] Uses ink whose drying time changes depending on the temperature.

It is divided into a plurality of parts along the path of the recording medium and is called a heating element.

A duty detection unit is provided, and the duty detection unit detects the amount of ink ejected to be recorded on each of the divided areas of the heating element, and the ink attached to the divided area on the recording medium is dried for each of the heating elements. Heating is controlled to a suitable temperature.

[Function] As described above, according to the present invention, it is possible to perform optimal heating according to the recording density in each recording area, and uniform recording quality can be achieved. Furthermore, it can be expected to improve the efficiency of electric power.

[Example] The illustrated embodiment will be described below.

In FIG. 1, 1 is a recording head and 2 is a recording medium. 3a to 36 are heating elements, all of which are divided in the serial direction, which is the operating direction of the recording head 1, and arranged on the path through which the recording medium passes. The recorded portion on the recording medium 2 is moved onto the heating elements 3° to 3d by line feed operation. heated. 4. ~46 is heating element 3-to-3,
A temperature detection element for detecting the temperature of each I is thermally closely coupled to the 9 heating elements.

In FIG. 2, reference numeral 5 denotes a duty detection section, which inputs recording data and detects each heating element 3. The density of each ink recorded in the area receiving heat of 6. to 3d is detected, and each duty level signal 6. ~66 is output. 7°-'7d is heating element 3. -36 temperature control circuits. The temperature control circuit 7s inputs the duty level signal 61 and the resistance value of the temperature detection element 4°, and receives the two heating element control signals 88 from the heating element drive circuit 9. 1 heating element drive circuit 98 provides a heating element control signal 8. In response to this, when the heating element control signal 8° is at a high level, current is supplied to the heating element 32 to heat it. 9b~
9d is a heating element drive circuit, and each temperature control circuit 7h to 7
Current is supplied to the heating elements 3b to 3d in response to heating element control signals 8b to 8d, which are the outputs of the heating element d.

In the internal circuit of the temperature detection circuit 7°, ■・ is the resistance R,
+ a and temperature detection element 4. It is given by the partial pressure with the resistance value of . Duty level signal 6. is 2 in this example
It is expressed in bits and is 61 and 6.2, respectively. The transistor T r I at T r' 2 m is turned on and off by duty level signals 6a+ and 6i2.
Give L, V-. The comparator IC+# successively compares one input terminal ■- and (-input terminal ■) and outputs a heating element control signal 7. 6 Temperature detection circuit 7b=76 has a similar configuration.

Next, the operation of the ninth embodiment will be explained from FIG.

Record data to heating element 3. -3D divided into regions each receiving heat. Each duty level detected by the duty detection unit 5 is set to level 1. Level 2, 1/Bell 0.
Set to level 3.

For simplicity, heating element 3. 7 Duty 1 novel describes the operation of the duty level signal 6. The data is then converted into a binary code and input to the temperature control circuit 7.

Since the detected duty level is 1, the duty level signal 61 is high, Bell, 6.2], o
The level becomes W, and the transistor Tr is in the on state.
The transistor Tr2s is turned off. As a result, one input terminal V- of the comparator E C+ s determined by the partial pressure of the resistors R2, .
6 heating elements showing 1 3. The temperature is indicated by the resistance value of the temperature detection element 4.0 and the partial pressure v6 of the resistor R+a. Comparator ICh is V-+ and ■. Successively compare 9 heating elements 3. is lower than the ink drying temperature T+, V −+ <
1 heating element control signal 8° is high, a bell is output, 9 current is supplied to heating element 3°, and the temperature rises by L. 0 heating element 3. If the temperature is higher than the ink drying temperature T1, V-+>V. Next 2 heating element control signal 8. is 1
The ow level is output, the current supply to the heating element 9 is stopped, and the temperature drops.

In this way, the temperature of the heating element 38 is set to duty level 1.
The ink drying temperature T1 is controlled to be suitable for recording.

Similarly, the two heating elements 3b, 3c, and 3d are set to suitable ink drying temperatures T2 and T, respectively, depending on the duty level.
[], controlled by T3.

FIG. 4 shows the relationship between the duty level, the duty 1/bell signal 61, the negative input terminal v- of the comparator 1 notor IC+, and a suitable ink drying temperature according to the duty level.

In this example, the heating element is 38 to 3. The duty level signal is expressed as a 2-bit code of 6° + 16s2, but the duty level can be divided into smaller parts by increasing the number of heating elements or by increasing the number of bits of the duty level signal. This makes it possible to give a more appropriate ink drying temperature depending on the amount of ink on the recording medium.Also, it is possible to apply a more appropriate ink drying temperature to the 9 heating elements 3□ to 3d. However, in this example, it is possible to set a total of 16 control temperatures because each heating element can be set independently.7 As described above, the heat generated from each heating element can be set independently. 5 of the recording area that receives
Set multiple duty l/bels for the recording density within that area and select a resistor element that achieves a voltage that provides a suitable ink drying temperature according to each duty l/bel. By doing so, you can easily achieve your goal.

[Effect of the invention] (9a compared to the case of 18 heating elements as before)
Since the heating capacity of each heating element becomes smaller, the degree of freedom in selecting the elements of the nine heating elements is improved. Also.

In the case of one heating element, high-density Jθa in the - part of the recording area, 7
) Requires maximum calorific value for recording 1-. 2 for 5
1 According to the present invention, the maximum calorific value is required at high density:
Since only the heating element corresponding to the area where H exists,
It is possible to improve the efficiency of the power supply without generating excess heat, and it is also possible to prevent overheating of low-density recording areas (deterioration of recording quality due to this).

Furthermore, since it is possible to set the ink drying temperature independently for each heating element, the ink drying temperature can be set higher for areas with low heating efficiency, such as at both ends of the recording area, so that printing can be performed according to the structure of the recording device. Variations in heating efficiency over a region can be corrected.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a configuration diagram of an inkjet recording apparatus showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing a heating element temperature control method in FIG. 1, and FIG. FIG. 3 is a waveform chart showing temperature distribution on the recording area due to the operation shown in the figure. Figure 4 shows the duty level and input voltage v- of duty 1/bell signal shift and...
, Decorate, Ilebe /I, l':According to l': /ip
i* 4z There is a diagram C showing the relationship between ink dryness, tm 2 m 1a- 1m R, s a Resistance IC+- Comparator Tr 1m Tr2@ Transistor or more

Claims (1)

[Claims] In an inkjet recording device that uses ink whose drying time changes depending on the temperature, it records by ejecting ink droplets.
A heating element divided into a plurality of parts and a duty detection section are provided in the passage path of the recording medium, and the duty detection section detects the amount of ink ejected to be recorded in each divided area of the heating element, and the amount of ink ejected to each of the heating elements is A temperature compensation method for an inkjet recording apparatus, characterized in that heating is controlled to a temperature suitable for drying the ink attached to the divided areas on the recording medium.