JP2001301139A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus in which high speed printing can be carried out without enlarging a print head. SOLUTION: In an ink jet imaging apparatus for printing on a recording material 3 wound around a rotary drum 2 using a print head 1, a large number of print heads 1 are arranged spirally around the rotary drum 2. More specifically, the print heads 1 are secured to the inner circumferential part of a holder 6 movable in the axial direction of the rotary drum 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet type image forming apparatus, and more particularly to printing on a recording material (paper, cloth, etc.) wound around a rotating drum while fixing a print head and rotating the rotating drum. And a type of image forming apparatus.

[0002]

2. Description of the Related Art There are two types of image forming apparatuses of the ink jet type, in which a print head is moved to perform printing.
As described above, there is a type in which printing is performed on a recording material wound around a rotating drum while the print head is fixed and the rotating drum is rotated. In the latter image forming apparatus, since the axial direction of the rotary drum is the main scanning direction, a print head (a wide width) having a length equal to or longer than the print width (axial length) of the recording material wound around the rotary drum is used. Print head).

[0003]

As described above, in an image forming apparatus of the type in which a print head is fixed and printing is performed on a recording material wound around a rotating drum while rotating the rotating drum, a wide width is used. Since the print head is required, the print head becomes large.

Further, the printing resolution is determined by the arrangement (pitch) of nozzles, and a print head must be manufactured in accordance with the resolution. A fine nozzle arrangement requires positional accuracy and is difficult to manufacture. However, there is a problem that as the size of the print head increases, the cost further increases.

The present invention presupposes a type in which a print head is fixed and printing is performed on a recording material wound around a rotary drum while rotating the rotary drum, and high-speed printing is performed without increasing the size of the print head. An object of the present invention is to provide a printable image forming apparatus.

[0006]

According to one aspect of the present invention, there is provided an image forming apparatus of an ink jet system for performing printing on a recording material wound around a rotary drum using a print head. , A large number of print heads are spirally arranged around a rotary drum.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the print head is held by a holding member movable in the axial direction of the rotary drum.

According to a third aspect of the present invention, in the image forming apparatus of the second aspect, the holding member is formed in a cylindrical shape, and the print head is fixed to an inner peripheral portion thereof. .

According to a fourth aspect of the present invention, in the image forming apparatus of the first aspect, the rotation of the rotary drum and the printing by the print head are synchronized.

According to a fifth aspect of the present invention, in the image forming apparatus of the fourth aspect, a signal of a rotary encoder provided on the rotary drum is input to the print head control unit via the synchronization detection unit. It is characterized by having.

According to the first aspect of the present invention, since the print head is spirally arranged around the rotary drum and printing is performed while rotating the rotary drum, wide print is efficiently performed by the print head which is not wide. Will be

According to the second and third aspects of the present invention, since the print head is attached to the inner peripheral portion of the holding member movable in the axial direction of the rotary drum, when the recording material is wound around the rotary drum, The print head can be retracted to a position (for example, above) away from the rotating drum, and the work of attaching the recording material can be performed quickly.

According to the fourth and fifth aspects of the present invention, since the rotation of the rotary drum and the printing by the print head are synchronized, high-definition printing is performed without being affected by uneven rotation of the rotary drum.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an image forming apparatus showing an embodiment of the present invention, and FIG. 2 is a front view of a print head. The ink jet type image forming apparatus shown in FIG. 1 prints on a recording material 3 wound around a rotating drum 2 by a print head 1. The recording material 3 is usually coated paper, but may be cloth as long as a special ink is used. The rotating drum 2 is rotated by an AC motor 4. A rotary encoder 5 is attached to the shaft of the rotary drum 2.

The print head 1 of the present invention is characterized in that a number of print heads are spirally arranged around a rotary drum 2. Specifically, the print head 1 is fixed to the inner peripheral portion of the cylindrical holder 6 in a spiral shape. A curve indicated by a symbol A schematically shows a state in which the print head 1 is spirally arranged. The size of the rotating drum 2 varies depending on the size of the print size, but in the present invention, a drum as wide as possible is suitable.

The holding member 6 is movable in the axial direction of the rotary drum 2, that is, in the vertical direction in the figure. Therefore, the print head 1 fixed to the inner peripheral portion of the holder 6 can also move in the axial direction of the rotating drum 2.

The rotary encoder 5 mounted on the shaft of the rotary drum 2 is connected to a synchronization detection unit 7. The synchronization detection unit 7 is connected to the print head control unit 8. Accordingly, the rotation speed of the rotary drum 2 is detected by the rotary encoder 5, and its signal is taken into the print head control unit 8 via the synchronization detection unit 7 to control the print timing, thereby controlling the rotation of the rotary drum 2 and the print head 1. , It is possible to always perform high-definition printing even if the rotating drum 2 has uneven rotation.

As shown in FIG. 2, the print head 1 is provided with nozzle holes 11 arranged at a reference resolution. Although the image forming apparatus of the present embodiment is assumed to be monochrome, it is of course possible to provide a color image forming apparatus by providing print heads of Y, M, C, and K colors.

Prior to the printing operation, first, the print head 1 is retracted from the rotating drum 2 by moving the holding member 6 upward in FIG. In this state, the recording material 3 is wound around the rotating drum 2. Thereafter, the holder 6 is lowered, and the print head 1 is moved to a predetermined position on the rotating drum 2.

Then, printing is performed by the print head 1 on the recording material 3 on the rotating rotating drum 2. Here, since the print head 1 is spirally arranged, the rotation of the rotary drum 2 sequentially prints the recording material 3 in the main scanning direction. That is, printing can be performed on the recording material 3 using the print head 1 that is much shorter than the width (length in the axial direction) of the recording material 3, that is, not wide.

As described above, the rotation speed of the rotary drum 2 is detected by the rotary encoder 5 and its signal is input to the print head control unit 8 via the synchronization detection unit 7, so that the printing of the print head 1 can be performed. The rotation of the rotating drum 2 is synchronized so that accurate printing is performed.

[0022]

According to the first aspect of the present invention, the print head is arranged spirally around the rotary drum, and printing is performed while rotating the rotary drum. Can be performed efficiently,
It is possible to reduce the size of the apparatus and the cost of manufacturing the print head.

According to the second and third aspects of the present invention, since the print head is attached to the inner peripheral portion of the holding member movable in the axial direction of the rotary drum, the recording material can be wound around the rotary drum. Can retract the print head to a position (for example, upward) away from the rotating drum, and can quickly perform the work of attaching the recording material.

According to the fourth and fifth aspects of the present invention, since the rotation of the rotary drum and the printing by the print head are synchronized, high-definition printing can be performed without being affected by uneven rotation of the rotary drum. I can do it.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a front view of a print head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Print head 2 Rotary drum 3 Recording material 4 AC motor 5 Rotary encoder 6 Holder 7 Synchronous detection unit 8 Print head control unit 11 Nozzle hole

Claims (5)

[Claims] 1. An ink jet type image forming apparatus for printing on a recording material wound around a rotary drum using a print head, wherein a number of print heads are spirally arranged around the rotary drum. An image forming apparatus comprising: 2. The image forming apparatus according to claim 1, wherein the print head is held by a holder that is movable in an axial direction of the rotating drum. 3. The image forming apparatus according to claim 2, wherein the holding member is formed in a cylindrical shape, and the print head is fixed to an inner peripheral portion thereof. 4. The image forming apparatus according to claim 1, wherein the rotation of the rotary drum and the printing by the print head are synchronized. 5. The image forming apparatus according to claim 4, wherein a signal of a rotary encoder provided on the rotary drum is input to a print head control unit via a synchronization detection unit. Image forming device.