JPS61242850A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To obtain a stable high-quality recorded image by supplying a discharge energy which is properly adjusted by an adjustment means to a recording head using an energy supply means, based on temperature information detected by a temperature detection means. CONSTITUTION:The temperature of a recording head 9 is detected by a temperature sensor 8, and its temperature information is read by a control 6 to perform arithmetic operation. Based on this operational result, an output voltage is determined as a voltage-variable power supply 5. In addition, the control 6 transmits a recording signal to a drive circuit 7, and the drive circuit 7 drives a recording head 9 according to the recording signal, using an output from the voltage-variable power supply 5. Consequently, if the temperature of the recording head increased significantly, a recorded image free from any satellite or ink mist can be obtained. Further, if a total calorific value were increased by the mounting of recording elements densely mounted on a large scale, satisfactory recording performance is assured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording device, and in particular, an inkjet recording device equipped with a means for optimizing drive energy given to a recording head for ejecting liquid according to temperature. The present invention relates to an inkjet recording device.

[Summary of disclosure]

The present invention provides an inkjet recording apparatus equipped with a recording head that records an image by discharging droplets onto a recording material, in which the energy supplied to the recording head for ejecting droplets is adjusted according to the temperature of the recording head. It can be so. This makes it possible to eject droplets optimally depending on the temperature, thereby realizing high quality recorded images.

Note that this summary is provided solely for the purpose of quickly accessing the technical contents of the present invention, and does not have any influence on the technical scope of the present invention or the interpretation of rights.

[Conventional technology]

The inkjet recording method is a recording method in which droplets of recording liquid (ink) are formed by various methods, and the droplets are attached to a recording material such as paper to perform recording.

Among recording devices (printers) that apply such recording methods, an inkjet type that uses heat as energy to form ejected droplets is a device with a structure suitable for high-density multi-orifice recording heads. One example is a printer.

Inkjet printers that use heat as the energy for ejecting droplets typically heat the recording liquid to give it a displacement that causes a sudden increase in volume.

A droplet forming means for forming droplets of recording liquid ejected from an orifice (droplet ejection hole) of a nozzle part, and electrothermal energy capable of generating heat and heating the recording liquid by applying an electric signal. Conversion element (hereinafter referred to as recording element)
The recording head is equipped with a recording head having:

FIG. 6 shows a drive circuit for driving a print head in a conventional inkjet printing apparatus. Here, a print signal is supplied to the base of a transistor 2 via a buffer 1, and a current flowing through a print element 3 is supplied to the base of a transistor 2. It's on/off. Conventionally, the voltage of the constant voltage power supply 4 is fixed,
The current flowing through the recording element 3 when the transistor 2 is turned on is always constant.

In other words, in conventional inkjet recording devices of this type, recording is performed by applying a constant amount of energy to the recording elements in response to a recording signal, regardless of the temperature of the recording head, such as the temperature of the ink inside the head. [Problems to be Solved by the Invention] However, in such conventional devices, when the temperature of the print head becomes significantly higher than room temperature, unnecessary droplets called satellites are ejected secondarily, causing the print image to deteriorate. There is a drawback that the quality of the recorded image deteriorates due to the fact that the satellites or ink mist adheres to the paper.

This is the threshold voltage v at which ink is ejected from the print head.
th has a negative temperature characteristic, and as the temperature of the recording head increases, it is related to a decrease in the ink ejection threshold voltage vth.

In other words, in conventional recording devices, only a preset constant energy is applied to the recording element, so if the temperature of the recording head rises, the recording element is driven at a higher voltage than the appropriate driving voltage. As a result, a phenomenon in which ink is ejected without proper droplet formation (splash) occurs, causing satellites and mist to adhere to the printed image, resulting in a decrease in recording quality. there were.

[Means for solving problems]

SUMMARY OF THE INVENTION An object of the present invention is to provide an inkjet recording device that can eliminate such conventional problems and obtain stable, high-quality recorded images over a wide temperature range.

In order to achieve such an object, the present invention, as shown in FIG. An energy supply means 110 that supplies energy, and that is, an energy supply means 11 that can adjust the energy.
0, temperature detection means 120 for detecting the temperature of the recording head 100, and adjustment means 130 for adjusting energy according to the detected temperature.

[For production]

That is, based on the temperature information detected by the temperature detection means 12G, the energy supply means 110 adjusts the adjustment means 130.
The ejection energy appropriately adjusted by the recording head 10
Supply to 0. As a result, stable droplet ejection is performed regardless of temperature conditions, and the quality of the recorded image is improved.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIGS. 2 and 3 are a block diagram showing an example of the configuration of an inkjet printer of the present invention and a line diagram showing a specific example of the configuration of its main parts, respectively. In these figures, 5 is a variable voltage power source as a driving power source for the recording element 83;
Reference numeral 6 denotes a control section that controls each section during recording processing and the like, and executes a processing procedure that will be described later with reference to FIG. 7 is a drive circuit including a transistor 72 for switching the current flowing through the recording element 93 and a buffer 71 for driving the transistor 72; 8 is a temperature sensor for detecting the temperature of the recording head; 9 is the recording element 83; This is a recording head having an aggregate of .

Further, 10 is a ROM that stores control output data to be described later to the power source 5, and 11 is a program memory that stores control procedures executed by the control unit 6 during recording processing, as well as processing procedures shown in FIG. Furthermore, 12 is a RAM having a storage area for data related to recording and a work area.

Next, the operation of the above configuration will be explained.

In FIG. 2, the temperature of the recording head 9 is detected by the temperature sensor 8, and the control unit 6 reads the temperature information and performs calculations, and controls 1 to 16 control the voltage variable power source based on the calculation results. Set the output voltage of 5. Further, the control unit 6 sends a recording signal to a drive circuit 7, and the drive circuit 7 uses the output of the variable voltage power supply 5 to drive the recording head 9 in accordance with the recording signal.

Further, in FIG. 3, the operations of the power supply 5, drive circuit 7, and recording head 9 will be explained in detail.

The recording signal is sent to the transistor 72 via the buffer 71.
The transistor 72 turns on/off the current flowing through the recording element 3 according to the supply of the recording signal.

That is, the transistor 72 is turned on when a recording signal is supplied, and at this time, current flows through the recording element 93. Otherwise, the transistor 72 is turned off, and at this time, no current flows through the recording element 83. No, the operation of the recording element 3 is described in the Journal of the Institute of Image Electronics Engineers, No. 11.
It is described in detail in Vol. 2, No. 2 (1982), pages 88 to 71.

The output voltage of the variable voltage power supply 5 is set by a voltage control signal generated by the control unit 6 according to the temperature of the recording head 9.
The current flowing through the recording element 33 is controlled.

FIG. 4 shows an example of the temperature characteristics of the drive voltage of the recording head, and as described above, the drive voltage has negative temperature characteristics.

Therefore, based on this characteristic, in this example, the power supply 5 is set to correspond to addresses 1 to 8 of RQXIQ as shown in Table 1.
The control output data to be stored is stored, and the voltage 115 is set so as to generate voltages as shown in Table 2 in accordance with the supply of the data.

Table 1 Table 2 FIG. 5 shows an example of the temperature correction processing procedure by the control unit 6. First, in step S1, the control unit 6 controls the temperature sensor 8.
The temperature T read by is read and digitized.

In step 5AI-SA8, the read temperatures T are 0°C, 5°C, 10°C, 20°C, 30°C, and 4°C, respectively.
It is determined whether the temperature is 0° C., 50° C. or 55° C. or lower, and if the determination is affirmative, addresses 8 to 1 are set in the parameter A in steps SBI to SB8, respectively. In addition,
If a negative determination is made in step SA8 as well, it is assumed that an error has occurred.

In step S2, the RO indicated by the set value of A is
The stored control output data is read from the address of M10, and then, in step S3, the data is supplied to the power supply 5, and the present process ends.

For example, when the head temperature is 20° C., data 05H stored at address 4 of ROM10 is read out according to the processing procedure shown in FIG. 5, and the control signal output to variable voltage power supply 5 is set to 05H. At this time, the voltage variable power supply 5 is set to 30.0 as shown in Table 2. Generates a voltage of QV. This output voltage corresponds to the drive voltage at 20° C. on the temperature characteristic curve of FIG.

Similarly, the drive voltage can be adjusted appropriately at other temperatures as well.

〔effect〕

As explained above, according to the present invention, the energy applied to the recording element is corrected based on the temperature information detected by the temperature sensor, and even if the temperature of the recording head increases significantly, satellites and ink mist are This has the effect that a good recording operation can be performed even if the recording elements are mounted on a large scale and with high density and the total amount of heat generated increases.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of an inkjet recording apparatus of the present invention, FIG. 2 is a block diagram showing an example of the configuration of the apparatus of the invention, and FIG. 3 is a diagram showing an example of the configuration of its main parts. FIG. 4 is a characteristic curve diagram showing an example of the temperature characteristics of the drive voltage of the recording head. FIG. 5 is a flowchart showing an example of a driving voltage temperature correction process procedure in the apparatus of the present invention, and FIG. 6 is a diagram showing an example of the main parts of a conventional inkjet recording apparatus. 1.71... Buffer, 2.72... Transistor, 3.93... Recording element, 4... Power supply, 5... Voltage variable power supply, 8... Control unit, 7... Drive circuit, 8... Temperature sensor, 8... Recording head, lO... ROM, 11... Program memory, 12... RAM, 100... Recording head, 110... Energy supply means . 120...Temperature detection means, 130...Adjustment means. Figure 3 Head 1 Figure 4 Figure 6 Figure 5

Claims (1)

[Scope of Claims] A recording head that records an image by discharging droplets onto a recording material, and an energy supply means for supplying energy for discharging the droplets to the recording head, the energy supply means for supplying the energy for discharging the droplets to the recording head. An inkjet recording apparatus comprising: an adjustable energy supply means; a temperature detection means for detecting the temperature of the recording head; and an adjustment means for adjusting the energy according to the detected temperature.