JPS61197247A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To enable a driving voltage to be automatically set when changing an unit to save trouble for adjustment and to keep the optimum ink discharge condition, by providing a voltage setting part in a printing head unit to automatically set driving voltage at the time of unit replacement. CONSTITUTION:An unit 2 comprises a baseplate 6 provided with head elements 5, an electric circuit such as a head driving circuit, an ink supply system, and in the rear thereof an interface part 8 having a connecter 7. A voltage setting part 9, provided in the interface part 8, sets the driving voltage VH intrinsic to the unit 2 and is so constructed as to electrically connected to a controller in the device through the connecter 7 to be controlled thereby. Accordingly, when replacing the unit, the head driving voltage can be automatically controlled to be intrinsically optimum value without special adjustment operation, resulting in improving management of the recording device and maintaining the optimum ink discharge condition. As the result, improvement of the printing quality can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to the structure of an ink jet recording apparatus equipped with a replaceable print head unit.

[Prior art]

An inkjet recording device supplies ink to a plurality of ink ejection ports formed in a print head and drives the ink ejection ports based on data signals, thereby depositing ink droplets on paper for recording. .

In addition, there are two types of inkjet recording devices: the line print type, in which ink ejection ports for one line are arranged in the print head, and records while scanning in the paper feed direction; There is a serial print type that prints while scanning in the same direction.

Furthermore, in color printing devices such as color graphic recorders (CGR), a plurality of print heads are installed depending on the ink color, such as yellow, magenta, cyan, and black.

Such an inkjet recording apparatus is generally configured such that a print head section including a print head, a head drive circuit, etc. is formed into a unit, and each unit can be replaced.

However, in inkjet recording devices, variations in the hole diameter and shape of the ink ejection ports, or electric heat generated by energy generating elements such as heating elements, which generate energy used to eject ink from the ejection ports, are a problem. Due to variations in the characteristics of electromechanical energy converters such as energy exchangers and piezoelectric elements, the appropriate drive voltage, that is, the drive voltage for achieving the optimum ink ejection state, may differ from print head unit to printhead unit. For example, when the standard drive voltage is 5V, there will be variations such that some print heads will exhibit an optimum ejection state at 4.8V, while other print heads will exhibit an optimum discharge state at 5.2V.

Therefore, conventionally, when replacing the print head unit, a drive voltage was applied, a voltage at which optimum ejection was obtained was measured, and the voltage was adjusted based on this.

However, with such conventional technology, there is a problem in that voltage adjustment work requires time and effort and accurate adjustment is difficult.

[Objective] The object of the present invention is to provide an inkjet recording device that can solve the problems of the conventional technology, can automatically set the drive voltage at the same time as replacing the print head unit, and can save the trouble of adjustment. It is to be.

[Summary] The present invention provides a voltage setting section for setting a head drive voltage unique to the print head unit in the interface section of the print head unit, and controls the head drive voltage from a control section based on the setting value of the voltage setting section. This configuration achieves the above object.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings, taking as an example a case in which it is applicable to a line print type color ink jet recording apparatus (CGR).

FIG. 1 shows a CGR head assembly 1, which includes four (lli print head units 2A,
It has a structure in which 2B, 2C, and 2D are installed in a case 3 in a replaceable (detachable) manner.

This head assembly 1 includes wiring 4 for receiving command signals and data signals from the controller section of the recording device.
is connected.

In addition, print head elements 5 for one line are attached to the front of each print hand unit) 2A, -, -2D, and ink droplets are attached to the paper (not shown) that is scanned and fed in front of these elements. and record images. In addition, in the illustrated example, each print head unit 2A...
- The print head elements 5 in 2D are arranged in a staggered manner in two rows, upper and lower.

One line is formed by, for example, 1792 dots (bits), and each print head element 5 has 128 bits (corresponding to the number of ink ejection ports), and 14 of these elements are arranged in a staggered manner.

Figure 2 shows the four print head units 2A-1 and 2 mentioned above.
2D (hereinafter referred to as unit 2), one side of a print head unit having 14 elements 5 arranged in a staggered manner is shown.

The unit 2 is constructed by mounting the print head element 5, an electric circuit such as a head drive circuit, an ink supply system, etc. on a base plate 6, and a connector (electrical connection part) at the rear of the unit 2.
An interface unit 8 having an interface unit 7 is provided.

This interface section 8 is provided with a voltage setting section 9 for setting a head drive voltage VH specific to the printing head unit 2. In the illustrated example, the voltage setting section 9 is composed of four on/off contacts connected in parallel, and is wired so as to be able to extract a voltage value consisting of 4 bits, that is, VH data of up to 16 levels. .

The head drive voltage (VH) data of the voltage setting section 9 is as follows:
By electrically connecting to the controller section of the device via the connector 7, the signal is taken into the controller section as a 4-bit signal 10, and the controller section controls the head drive voltage VH based on the signal (voltage setting signal). It is configured like this.

The VH data of the voltage setting section 9 may be obtained by, for example, measuring the optimum head drive voltage through an ink ejection test conducted for each print head unit at the factory, and turning a predetermined contact into an on/off state based on the measurement result. It can be set by

FIG. 3 is a program diagram illustrating the head drive voltage control system of the inkjet recording apparatus described above, and shows the characteristics of the The H data signal 10 is taken into the controller section 11 of the apparatus, and the controller section 1 controls the voltage of the variable power supply 11 for driving the head based on this data signal 10, and controls the drive voltage VH to obtain the optimum ink ejection. do.

According to the head drive voltage control means described above, variations in the hole diameter and shape of the ink ejection ports of the print head and variations in the characteristics of the energy generator that generates the energy used to eject ink from the ink ejection ports are eliminated. Even in such cases, when replacing (or assembling) the print head unit 2, the head drive voltage could be automatically controlled to its own optimum value for each print head unit without requiring any special adjustment work. . Therefore, there is no need to adjust the voltage when replacing the unit as in the past (this makes it possible to improve the handling of the inkjet recording device and improve print quality by maintaining the optimal ink ejection condition).

In this case, it was easy to provide the setting section (voltage setting section 9) in the interface section 8 by writing or the like, and there was no influence on the production process.

In the above embodiment, the head drive voltage VH is set to 4.
Although this was done using bit data, the number of bits can be selected as needed.

Further, the present invention can be applied regardless of the dot arrangement or the number of print head units 2 installed, and can also be applied to a serial print type.

〔effect〕

As is clear from the above description, according to the present invention, it is possible to eliminate the work of adjusting the head drive voltage, and to obtain an inkjet recording apparatus that can control the drive voltage of each printing head unit to an appropriate value.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a print head assembly of an ink jet recording apparatus suitable for use with the present invention, FIG. 2 is a schematic plan view of a print head unit of an embodiment of an ink jet recording apparatus according to the present invention, and FIG. The figure is a block diagram illustrating a head drive voltage control system of an inkjet recording apparatus according to the present invention. 2, 2 A---1--2D: Print head unit, 5--Print head element, 8--Interface section, 9--Voltage setting section, 10--
−・Drive voltage setting signal, 11−・−・Controller section,
VH-- Head drive voltage. Agent Patent Attorney Yasushi Oto Grain Cylinder 1 Figure 3

Claims (1)

[Claims] (1) In an inkjet recording apparatus equipped with a replaceable print head unit, a voltage setting section for setting a head drive voltage specific to the print head unit is provided in an interface section of the print head unit, and the voltage setting section is set. An inkjet recording device configured to control head drive voltage from a control unit based on the value.