JPH07156373A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To realize a transfer type ink jet recorder in which a preheating time is shortened by varying a recording speed according to a transfer drum surface temperature. CONSTITUTION:A temperature of a transfer drum is detected by a temperature sensor 14, and recording speed data is read by referring to a data table of a ROM 53 with the temperature as an offset amount. The data is set to a pulse generator in a controller 51, and a driving pulse is supplied to a drum driving motor driver 54 to start rotating of the drum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus. In particular, the present invention relates to a transfer type inkjet recording apparatus that forms an ink image on a transfer medium by a recording head and then transfers the image to the recording medium to perform recording.

[0002]

2. Description of the Related Art A transfer type ink jet recording apparatus has a feature that ink jet clogging caused by unintentional contact between recording paper or paper dust and a recording head does not occur, and high reliability can be obtained. As a conventional transfer type ink jet printer, the configuration described in Japanese Patent Laid-Open No. 59-225958 is known.

In this apparatus, an ink jet recording head (hereinafter referred to as a recording head) having a plurality of nozzles is provided on a cylindrical transfer medium with a gap therebetween. When an ink image is formed on the transfer medium by the recording head,
The recording head forms an ink image on the cylinder while moving in the direction parallel to the plurality of nozzles in response to the image signal in synchronization with the rotation of the cylindrical transfer medium. Then, the recording medium is brought into contact with the transfer medium and pressed from the back of the recording medium to transfer the ink image onto the recording medium, and the recording medium is conveyed in the paper discharge direction.

There is also known a method of controlling a drying heater for drying and fixing a recorded ink image (Japanese Patent Laid-Open No. 4-169236).

[0005]

However, in the above configuration, it is necessary to heat the recording medium and maintain it at a specific temperature in order to dry the ink image. Printing cannot be performed until it is heated up, and a waiting time occurs. Therefore, normally, the heater is energized in order to maintain the temperature of the recording medium even when the apparatus is in a standby state with the power source turned on. This eliminates the need for waiting time before printing, but increases power consumption.

The present invention solves this problem, and an object thereof is to obtain a transfer type ink jet recording apparatus which consumes less power and can print immediately after power is turned on.

[0007]

An ink jet recording apparatus according to claim 1, wherein an ink image is formed on a transfer medium surface in an image writing step and is transferred to the recording medium in the transfer step to obtain an ink image. An ink jet recording apparatus comprising: a means for detecting the temperature of the surface of the transfer medium; and a control means for varying the recording speed based on the temperature.

An ink jet recording apparatus according to a second aspect of the present invention is further characterized in that the control means controls the recording speed to increase as the transfer drum temperature rises.

[0009]

According to the above construction, the temperature on the transfer medium is detected, the recording speed which is the optimum drying condition for the temperature is calculated, and the recording speed on the transfer medium is changed. As a result, it is possible to perform printing even when the temperature on the transfer medium does not reach a steady state, and it is possible to configure an inkjet recording apparatus that shortens the preheating time when the power is turned on.

[0010]

EXAMPLES Examples of the ink jet recording apparatus of the present invention will be described in detail below.

FIG. 1 shows a perspective view of an ink jet printer which is a first embodiment. An inkjet recording head 2 and a transfer roller 3 that is a transfer unit are sequentially arranged around a transfer drum 1 that is a transfer medium.

The recording head 2 is an ink jet recording head of a type using a piezoelectric element, and is supplied with ink from an ink container 28 through an ink supply pipe 29 and has a plurality of nozzles at regular intervals in the axial direction of the transfer drum 1. ing. In the case of this embodiment, the recording head 2 has 512 nozzles at a 16/600 inch pitch.

The head moving device 23 comprises a drive motor 24, a recording head holding member 25 and a moving guide 26,
The recording head 2 fixed on the recording head holding member 25 is moved along the movement guide 26 by the drive motor 24 in the axial direction of the transfer drum 1 by 1/6 for one rotation of the transfer drum 1.
The head is arbitrarily moved up to 15/600 inches in units of 00 inches.

The transfer drum 1 is formed by laminating an elastic layer made of silicone rubber around a metal tube having an outer circumference of 10 mm.
Inches. The transfer drum 1 is driven by a drum drive motor 11. The drum drive motor 11 is a step motor, and the recording speed can be changed by changing the frequency of the motor drive pulse. The drum rotation encoder 12 is a timing mark 13 mounted on the transfer drum 1.
Is detected and one pulse of origin signal and rotation speed signal are output per one rotation of the transfer drum 1. Rotation speed signal is 1/6
6000 pulses are generated for each rotation of the transfer drum every 00 inches, and 4864 pulses are used as the print timing of the recording head.

A drying heater 1 is provided on the rotary shaft of the transfer drum 1.
6 is provided to uniformly heat the surface of the transfer drum 1 from the inside. A fixed drum temperature sensor 14 contacts the non-recording area of the transfer drum 1 to detect the surface temperature of the transfer drum 1.

The transfer roller 3 is an aluminum metal roller, and is structured so that it can be pressed and released from the transfer drum 1 by the transfer pressure applying device 33. When pressed, it rotates at the same speed as the peripheral speed of the transfer drum 1 in the direction of arrow D in the figure through the recording paper 4 which is a recording medium. The transfer pressure is
In this embodiment, the weight is set in the range of 10 to 50 kg.

Next, the operation will be described. Image formation
An image writing step of forming an ink image on the transfer drum 1 and a transfer step of transferring the ink image formed on the transfer drum to a recording sheet are performed.

The image writing process will be described with reference to FIGS. The recording area on the transfer drum 1 is divided into 16 areas for each nozzle of the recording head 2. The recording head 2 is positioned by the recording head moving device 23 according to the block to be recorded first. Next, while the transfer drum 1 makes one rotation in the direction of arrow A, ink is ejected onto the transfer drum 1 from nozzles (represented by two nozzles, nozzle 200 and nozzle 201 in FIG. 2).
An ink image is formed. This is the dot row 20 in FIG.
2, the dot row 203. After the writing of one rotation to the transfer drum 1 is completed, the recording head 2 moves to the next writing block in the direction of arrow B in units of 1/600 inch. The transfer drum 1 enters the second rotation. Similarly to the first rotation of the transfer drum 1, a dot row is formed on the transfer drum 1. Similarly, the nozzle pitch h = 16
Since it is / 600 inches, the transfer drum 1 rotates 16 times and an image for one page is formed on the transfer drum 1. After that, the recording head 2 moves in the direction opposite to the arrow B to prepare for the next recording.

A method of changing the recording speed will be described with reference to FIG. When the print command and the print data are sent from the host computer 50, the controller 51 expands the print data in the image memory 52 in accordance with the print command and at the same time starts the energization of the drying heater 16. When the development of the print data is completed, the temperature of the transfer drum 1 is detected by the temperature sensor 14, and the temperature is used as an offset amount to refer to the data table of the ROM 53 to read the recording speed data. The recording speed data is set in a pulse generation circuit (not shown) inside the controller 51, and a drive pulse is supplied to the drum drive motor driver 54 to rotate the transfer drum 1. When the transfer drum 1 starts to rotate, the drum rotation encoder 12 outputs an origin signal and a rotation speed signal. The range in which the print pulse is valid is 4864 pulses after the rotation speed signal is counted 400 pulses from the detection of the origin signal for one revolution of the transfer drum 1. Sent to print pulses. The recording speed is changed in the non-printing range of one round of the transfer drum 1. To change the recording speed, the temperature of the transfer drum 1 is detected by the temperature sensor 14 each time printing of one round of the transfer drum 1 is completed, and the recording speed data corresponding to the temperature is referred to the ROM 53 to generate a pulse inside the controller. Set a new drive pulse in the circuit and drive the drum drive motor driver 54
Supply to. The above operation is repeated 16 times and the transfer drum 1
The recording of one page is completed.

FIG. 5 shows a graph of the peripheral velocity of the transfer drum 1 corresponding to the temperature of the transfer drum 1 stored in the ROM 53. When the temperature of the transfer drum 1 is between 30 ° C and 90 ° C, the peripheral velocity at the time of recording of the transfer drum 1 is from 100 mm / S to 1
It changes to 000 mm / S. When the temperature of the transfer drum 1 is low, sufficient heat energy required for drying cannot be obtained, and the time required for the drying up to the transfer step becomes long. Therefore, the recording speed is set low, and as the temperature of the transfer drum 1 increases. Since the thermal energy increases and the time required for drying is shortened, the recording speed is increased.

Next, the transfer process will be described. After the image for one page is formed on the transfer drum 1, the transfer roller 3 is pressed against the transfer drum 1. Transfer is started by conveying the recording paper 4 to the contact portion at a timing such that the recording start position corresponds to the leading portion of the recording paper by the paper conveying means 41 (see FIG. 1). The transfer roller 3 is released from the transfer drum 1 and the recording paper 4 is ejected at the timing when the trailing end of the recording paper 4 has finished the transfer and passes through the contact portion.

With the above, recording for one page is completed. After the recording is completed, the energization of the drying heater is stopped, but when the recording is a print command for a plurality of sheets or when the print command and print data are sent from the host computer 50 after the recording for one page is completed. Then, the recording operation is continuously performed and the energization of the drying heater is also continued.

FIG. 6 is a perspective view of the ink jet recording apparatus according to the second embodiment. A recording head 2 is arranged around the transfer drum 1. The recording head 2 is a carriage 21.
A carriage drive motor 24 and a carriage drive belt 27 are driven in both directions A and B on a carriage shaft 24 which is attached above and is arranged in parallel with the axis of the transfer drum 1. A carriage position encoder 12 is attached to the carriage 21, and the timing mark 13 is generated when the carriage moves on the carriage axis.
Is detected and a print timing pulse is generated.

Each time the carriage 21 scans in the A or B direction once, an area of width d is printed. The transfer drum 1 is rotated by the drum drive motor 11 in the direction C by the width d every time the carriage is scanned. When recording by carriage scanning is performed a plurality of times and the leading position of the recorded image on the transfer drum 1 reaches a position facing the transfer roller 3, the recording paper 4 is conveyed in the direction D by the paper feed roller 41 and is transferred by the pressure device 33 to the transfer roller 3 Is pressed against the transfer drum 1 and the recorded image is transferred onto the recording paper 4 and discharged.

As in the first embodiment, the transfer drum 1 is provided with a drying heater 13 on its shaft and a fixed drum temperature sensor 14 (not shown) is in contact with a non-recording area on the transfer drum.

A method of changing the recording speed will be described with reference to FIG. When the print command and the print data are sent from the host computer 50, the controller 51 expands the print data in the image memory 52 in accordance with the print command and at the same time starts the energization of the drying heater 16. Each time the development of print data for one scan of the carriage 21 is completed, the transfer drum 1
The temperature of the carriage 21 is detected by the temperature sensor 14, and the scanning speed of the carriage 21, which is the optimum recording speed for the detected temperature, is stored in the ROM.
The data is read from 53, set in a pulse generation circuit inside the controller 51, a drive pulse is output to the carriage drive motor driver 55, the carriage drive motor 24 is driven, and the carriage 21 is scanned to perform recording.

The relationship between the temperature of the transfer drum 1 and the scanning speed of the carriage 21 is low as in the first embodiment when the temperature of the transfer drum is low so that the scanning speed of the carriage 21 is dried by the transfer process. The scanning speed of the carriage 21 is set higher as the temperature rises as the drying time is shortened.

[0028]

According to the present invention, the temperature of the transfer medium at the time of recording is detected and the recording is performed at the recording speed that provides the optimum ink drying condition for the temperature, so that the temperature of the transfer medium is low immediately after the power is turned on. Recording is possible even in the state, and the preheating time is shortened. Further, it is possible to stop the energization of the drying heater in the standby state, and it is possible to reduce the power consumption. Further, since the temperature control of the transfer medium does not require high accuracy, the temperature control circuit can be simplified and an inexpensive device can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view of an ink jet recording apparatus according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing the operation of moving the recording head of the inkjet recording apparatus according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a recording method of the inkjet recording apparatus according to the first embodiment of the present invention.

FIG. 4 is a block diagram of a main part of the inkjet recording apparatus according to the first embodiment of the present invention.

FIG. 5 is a graph showing the relationship between the transfer drum temperature and the recording speed of the inkjet recording apparatus according to the first embodiment of the present invention.

FIG. 6 is a perspective view of an ink jet recording apparatus according to a second embodiment of the present invention.

FIG. 7 is a block diagram of a main part of an ink jet recording apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

 1: Transfer drum 2: Recording head 3: Transfer roller 4: Recording paper

Claims (2)

[Claims] 1. At least image writing means for forming an ink image on the surface of a transfer medium, drying means for drying the ink image on the surface of the transfer medium, and transfer means for transferring the ink image to a recording medium to obtain the ink image. An ink jet recording apparatus having the above, which has means for detecting the temperature of the surface of the transfer medium, and control means for varying the recording speed based on the temperature. 2. The ink jet recording apparatus according to claim 1, wherein the control unit controls the recording speed to increase as the temperature of the transfer drum increases.