JPH02255356A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To reproduce a clear color image without misregistering of colors by constituting an image forming apparatus of a recording medium supporting member which fixedly supports a recording medium between a recording head unit and a platen roller and a rotary member which supports said recording medium supporting member in a manner to freely rotate in a reciprocatory manner in a transferring direction, so that a paper is precisely transferred in a reciprocatory manner. CONSTITUTION:A paper bed 31 supported by a rotary member 32 transfers a paper P in a printing direction in accordance with the rotation of a platen roller 22 in a forward direction. An ink on a transfer ribbon 23 is transferred to the paper P by printing of a thermal head 21, thus forming an image. After the first printing is finished, the platen roller 22 is rotated in a reverse direction and the paper bed 31 is moved to a front end of the paper P. Since the recording medium supporting member is supported at the fulcrum of the rotation of the rotary member, the supporting member can be restricted as much as possible from being moved in a lateral direction, and accordingly the misregistering of colors can be positively prevented.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention relates to an image forming apparatus applied to multicolor image formation, such as a color copying machine or a color printer, and in particular, The present invention relates to an image forming apparatus in which a means for locating and transporting a recording medium is improved.

(Prior art) In recent years, recording media (hereinafter referred to as paper) are coated with transfer materials (hereinafter referred to as paper).
Transfer ribbon) contains multiple colorants (hereinafter referred to as "transfer ribbon").

An image forming apparatus that forms a desired color image by transferring ink (hereinafter referred to as ink) through a recording head (hereinafter referred to as a thermal bed) has been developed and put into practical use.

When forming a color image in such an image forming apparatus, a platen roller is used to locate the beginning of a sheet of paper, and as the platen roller rotates, the sheet of paper held between the thermal head is transferred while being transferred in the printing direction. There is a high-speed return method in which the paper is returned by transferring the ink from the ribbon and rotating the platen roller in the reverse direction at high speed after the first printing is completed.

(Problem to be Solved by the Invention) However, in the above-mentioned paper cueing method using high-speed reverse rotation of the platen roller, due to the flatness of the thermal head and the positional accuracy with respect to the platen roller, a vector different from the paper transport direction is generated. There is a problem in that the paper is likely to shift vertically or horizontally when the paper is transferred back and forth across the bottom due to the force exerted on it, resulting in color shift in the reproduced image.

The present invention was made under the above circumstances, and its purpose is to reproduce a clear color image without color shift by precisely transporting paper back and forth. An object of the present invention is to provide a forming device.

[Structure of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a platen roller, a recording head section positioned facing the platen roller so as to be able to approach and separate from it, and this recording head. and a transfer means that supports and fixes a recording medium fed between the unit and the platen roller, and transfers the colorant on the transfer material while transferring the recording medium in the printing direction as the platen roller rotates. , this transfer means includes a recording medium support member that supports and fixes the recording medium and is held between the recording head section and the platen roller, and a rotation member that supports the recording medium support member so as to be rotatable back and forth in the transport direction. In this case, it is preferable that an elastic contact member is attached to the contact surface of the recording medium supporting member with the platen roller.

(Function) That is, one aspect of the present invention is to transport a recording medium fed between a recording head section and a platen roller while supporting and fixing it to a recording medium support member of a transport means, and to rotate this recording medium support member. Since the recording medium supporting member is supported by the movable member so as to be rotatable back and forth in the transport direction, the recording medium support member is supported by the pivot point of the rotary member, thereby minimizing lateral movement.

Further, by pasting an elastic friction member on the contact surface of the recording medium support member with the platen roller, the adhesion between the recording medium support member and the platen roller is improved, and vertical displacement of the recording medium is also reduced.

(Embodiment) The present invention will be described in detail below with reference to an illustrated embodiment.

FIG. 2 schematically shows the overall internal configuration of an image forming apparatus according to the present invention, and 1 in the figure is the main body of the apparatus. A document table 2 is arranged on the upper surface of the apparatus main body 1, and a document holding cover 3 is provided on the document table 2.

Further, in the apparatus main body 1, a document scanning section (scanner section) 4 is disposed at the top to scan a document set on a document table 2 from below, and an image forming section (printer section) is disposed at the bottom. Section) 5 is arranged.

The document scanning section 4 includes a first mirror 8 having an exposure lamp 7 and a first mirror 8, the back of which is surrounded by a reflector 6.
a moving optical block 9, a second moving optical block 12 having a second mirror 10 and a third mirror 11, a fixed optical block 16 having a fourth mirror 14 and a fifth mirror 15, and a photoelectric conversion By moving the first movable optical block 9 along the M document platen 2, the image surface of the document sheet is optically scanned and its optical information is extracted. is reflected to a second moving optical block 12 that moves at half the speed of the first moving optical block 9, and the optical information reflected by this second moving optical block 12 is transmitted to a lens 13 and a fixed optical block. The signal is received by a photoelectric converter 17 via a block 16 and input to the image forming section 5.

On the other hand, the image forming section 5 includes a platen roller 22 located approximately in the center of the apparatus main body 1, and a platen roller 22 located approximately in the center of the apparatus main body 1.
2, a transfer ribbon 23 interposed between the thermal head 21 and the platen roller 22, and both ends of the transfer ribbon 23 passing through guide rollers 24 and 25. A transport means 30 that supports and fixes the paper P from the paper feed cassette section 28 that is fed between the core 26° 27 and the thermal head 21 and the platen roller 22 and transports it in the printing direction.
As shown in FIG.
A plate-shaped paper table 31 serving as a recording medium support member having a smooth curved surface is held between the thermal head 21 and the platen roller 22, and this paper table 31 is used as a rotation fulcrum 32.
Rotating member 32 supported rotatably in the transfer direction centering on a
and a gripper 33 that is provided at the upper end of the paper table 31 and that grips the leading edge of the paper P fed between the thermal head 21 and the platen roller 22 and supports and fixes it on the paper table 31. The contact surface 31a of the paper tray 31 with the platen roller 22 is formed into minute irregularities, and the contact surface 31a is coated with an elastic friction member 34 made of rubber or the like.
It has a structure made by pasting.

The paper table 31 supported by the rotating member 32 is
With the forward rotation of the platen roller 22, the paper P is transferred in the printing direction, and thereby the ink on the transfer ribbon 23 is transferred to the paper P by the printing of the thermal head 21.
This is a device that forms images, and when the first printing is completed,
As shown in FIG. 3, the platen roller 22 is rotated in the opposite direction to transport the paper table 31 to the leading position of the paper P.

Note that the present invention is not limited to the embodiments described above, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[Effects of the Invention] As is clear from the above description, according to the present invention, there is provided a platen roller, a recording head section positioned facing the platen roller so as to be able to approach and separate from it, and a connection between the recording head section and the platen roller. a transfer means that supports and fixes a recording medium fed therebetween and transfers the colorant on the transfer material while moving the recording medium in the printing direction as the platen roller rotates; It is composed of a recording medium support member that supports and fixes the recording medium and is held between the recording head section and the platen roller, and a rotating member that supports the recording medium support member so as to be rotatable back and forth in the transport direction. From becoming,
Since the recording medium support member is supported by the rotational fulcrum of the rotation member, lateral movement of the recording medium support member can be minimized, and moreover, the relationship between the recording medium support member and the platen roller can be minimized. By attaching an elastic friction member to the contact surface, it is possible to improve the adhesion between the recording medium support member and the platen roller, so there is less vertical displacement of the recording medium, which makes it possible to This has the excellent effect of reliably preventing the occurrence of color shift and reproducing clear color images.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing one embodiment of a paper cue means in an image forming section of an image forming apparatus according to the present invention;
This figure is a schematic cross-sectional view showing the overall configuration of the image forming apparatus, and FIG. 3 is a schematic explanatory view showing the operating state of the paper cue means in the image forming section. 22 ・ 23 ・ 30 ・ 31 ・ 1a 32 ・ 33 ・ 34 ・ P ・ ・ ・Platen roller, ・Transfer material (transfer ribbon), ・Transportation means, ・Recording medium support member (paper table), ・・Contact surface, ・Rotating member, 32a... Rotating fulcrum.・Gripper, ・Elastic friction member (rubber). Recording medium (paper). Applicant's representative Patent attorney Takehiko Suzue 1...Device body, 5...Image forming section (printer section),

Claims (1)

[Claims] A platen roller, a recording head portion located opposite to the platen roller so as to be able to approach and separate from the platen roller, and a recording medium fed between the recording head portion and the platen roller to be supported and fixed as the platen roller rotates. a transfer means that transfers the colorant on the transfer material while moving the recording medium in the printing direction, and the transfer means supports and fixes the recording medium and is held between the recording head section and the platen roller. An image forming apparatus comprising a recording medium support member and a rotating member that supports the recording medium support member so as to be rotatable back and forth in a transport direction.