JPS63176166A - Image forming device - Google Patents

Abstract

PURPOSE:To simplify the mechanism and th control method while maintaining essential function of an information recording means, by arranging the same member as an outer circumferential member of a bearing material at a portion facing with the information recording means in a fixed mechanism section. CONSTITUTION:In a gripper 2, upper face section 3a of a rotary member 3 supported rotatably in a recess 30 is curved with curvature corresponding to that of the outer circumferential face of a platen roller 22, and applied with resilient material, i.e. a rubber coating member 4, with the outer circumferential face 4a being matched with a curved face formed by the outer circumferential face of a rubber sheet 22a provided on the outer circumference of the platen roller 22. when characters or random colors are overlapped onto a recording sheet P by means of a thermal printing head 21, the surface of thermal printing head 21 is not damaged even if the rubber coating member 4 applied onto the outer circumference of the gripper 2 contacts with the thermal printing head 21, becomes the outer peripheral part of the gripper 2 is covered with the rubber coating member 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the invention] An apparatus for forming images by polymerization, such as a multicolor printer,
The present invention relates to an image forming apparatus useful in facsimiles, copying machines, etc.

(Prior Art) In color copying machines and the like that record and display a single color or multiple colors in a superimposed state on a single sheet of recording paper, the outer periphery of a drum-shaped platen roller is usually used to improve the superposition accuracy of each color. A gripper is used to fix the recording paper to this platen roller.

A conventional example of an image forming apparatus including such a gripper is shown in the third example.
This will be explained with reference to the figures and FIG.

The image forming apparatus 20 shown in the same figure is composed of characters and symbols.

A thermal printing head 21 that records various types of information such as graphics (hereinafter referred to as "image information") on recording paper P as a recording medium, and a drum-shaped drum disposed opposite to this thermal printing head 21 on the outer periphery. A platen roller 22 whose portion is covered with a rubber sheet 22a, and a gripper 2 provided on the outer periphery of the platen roller 22.
3, and an ink ribbon 24 inserted between the thermal printing head 21 and the platen roller 22.
, a pair of rollers 25 a and 25 b that send out and wind up the ink ribbon 24 , and the surface of the recording paper P on which the ink ribbon 24 is wound around the head surface of the thermal printing head 21 and the outer periphery of the platen roller 22 . guide rollers 26a and 26b that guide the recording paper P against the outer peripheral surface of the platen roller 22, pressure rollers 27a and 27b that press the recording paper P against the outer peripheral surface of the platen roller 22, a paper support piece 28 and a supply roller 2 that supply the recording paper P to the platen roller 22.
9.

Incidentally, as shown in FIG. 4, the gripper 23 is a rotatable gripper made of, for example, metal and rotatably supported by a support shaft 3'la in a recessed hole 30 provided in a part of the outer circumference of the platen roller 22. The piece 31, a rubber clamping body 32 attached to the lower surface side of the rotating piece 31, and a rubber clamping body 32 that is located inside the recessed hole 3Q and facing the rotation area of the clamping body 32 attached to the rotating piece 31. As shown in FIG. As a result, the recording paper P is fixed to the platen roller 22.

However, in the gripper 23 having such a configuration, the outer surface side of the rotating piece 31 is exposed to a part of the outer periphery of the platen roller 22.
2 in the direction of the arrow as shown in FIG. is the thermal printing head 21
The thermal printing head 21 must be separated from the -H platen roller 22 while the thermal printing head 21 is passing over the head surface of the -H platen roller 22.

As a result, the support mechanism for the thermal printing head 21 becomes complicated and the control method thereof becomes difficult.
This poses a problem in that the recording speed of the thermal printing head 21 deteriorates and the accuracy of superimposing each color on the recording paper P deteriorates.

FIG. 5 shows another example of the conventional gripper. The gripper 23a, which is not shown in the same figure, has a mounting hole 34 formed inward from a part of the outer periphery of the platen roller 22.
A spring 36 is attached between the lower end 35a of the clamping body 35 and the bottom of the mounting hole 34, and the clamping body 35 is always placed inside the platen roller 22. It is designed to be energized. The clamping piece 35b contacts the outer circumference of the platen roller 22.
The end of the recording paper [] is held between the rubber sheet 22a and the rubber sheet 22a.

However, even in the gripper 23a having such a configuration, the gripping side portion 35b is exposed on the outer periphery of the platen roller 22, and therefore has the same problem as the gripper 23 shown in FIG. 4.

(Problems to be Solved by the Invention) As described above, in the conventional image forming apparatus, due to the structure of the gripper provided on a part of the platen roller, the gate structure becomes complicated and the control method becomes difficult. In addition, there is a problem that the recording speed and the superposition accuracy of each color are adversely affected.

Therefore, the present invention improves the structure of the gripper as a fixing mechanism, thereby making it possible to simplify the front bridge and control, and to maintain the original recording speed and superimposition accuracy of each color. The object of the present invention is to provide a forming device.

[Structure of the Invention] (Means for Solving the Problems) The present invention comprises an image information recording means, and a drum-shaped drum that is provided opposite to the image information recording means and transports a recording medium by wrapping it around its outer circumference. In an image forming apparatus comprising a carrier and a fixing mechanism provided on a part of the outer periphery of the carrier and fixing the recording medium to the carrier, a portion of the fixing mechanism facing the information recording means is provided. , is constructed by arranging members equivalent to the members forming the outer periphery of the carrier.

(for production) The operation of the apparatus having the above configuration will be explained below.

According to this device, a member equivalent to the member forming the outer periphery of the carrier is disposed in the portion facing the information recording means in the fixing mechanism section for fixing the recording medium provided on the carrier. The state of contact of the body with the information recording means is equalized over its entire circumference, thereby preventing damage to the information recording means.

(Example) An example of the present invention will be described below with reference to FIG. 1 and FIG. 2(a). In the image forming apparatus 1 shown in FIGS. 1 and 2 (a), parts having the same functions as those of the conventional apparatus shown in FIG. .

The configuration of the image forming apparatus 1 shown in FIG. 1 is substantially the same as that shown in FIG. The groove path of the gripper 2 is different from that of the gripper 23 shown in FIGS. 3 and 4. However, as shown in FIG. The upper surface portion 3a of the rotating member 3, which is rotatably supported in the platen roller 22, is formed into a curved shape having a curvature corresponding to the curvature of the outer periphery of the platen roller 22. The outer peripheral portion 4a of the covering member 4 is adapted to match the curved surface formed by the outer peripheral surface of a rubber sheet 22a provided around the outer periphery of the platen roller 22.

Note that the configuration of other parts of this gripper 2 is the same as that shown in FIG. 4.

According to the image forming apparatus 1 having the gripper 2 configured as described above, the recording paper P is fixed to the outer periphery of the platen roller 22 by the gripping function of the gripper 2, and the platen roller is rotated in the direction of the arrow shown in FIG. When the thermal printing head 21 serving as an information recording means superposes characters or any color on the recording paper P, the outer periphery of the gripper 2 is covered with a rubber covering member 4. 4 comes into contact with the thermal printing head 21, the head surface will not be damaged unlike the conventional apparatus.

As a result, it is no longer necessary to separate the SUMARP 1 nonting head 21 from the platen roller 22 as in the conventional device, the support mechanism and control method thereof can be simplified, and the recording by the thermal printing head 21 can be simplified. There is no adverse effect on speed or polymerization accuracy of each color.

FIG. 2(b) shows a modification of the gripper in the apparatus according to the embodiment of the present invention.

The gripper 2a shown in the same figure has a part of the outer circumference of the platen roller 22 that is slightly larger than the outer circumference of the platen roller 22.
A holding portion 5 is formed which is recessed inwardly, and a holding member 7 having a holding piece 7b@m attached to the receiving portion 5 is attached to the platen roller 22 in a configuration similar to that shown in FIG.

A covering member 6 similar to the covering member 4 shown in FIG. 1 is disposed on the upper surface side of the holding piece portion 5b.

Even when the gripper 2a having such a configuration is used, the same function as the gripper T shown in FIG. 1 can be achieved.

It goes without saying that the present invention is not limited to the embodiments described above, and that various modifications can be made within the scope of the paper.

For example, in the above-mentioned embodiment, a case was explained in which a rubber covering member was used for the fixed R structure. This can be carried out using various elastic bodies, if any.

[Effects of the Invention] According to the present invention described in detail above, the ljJHM and control method can be simplified by arranging a member equivalent to the outer peripheral member of the carrier in the part of the fixing mechanism facing the information recording means. Accordingly, it is possible to provide an image forming apparatus that can maintain the original functions of the information recording means.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view showing an embodiment of the present invention;
Fig. 2 (a) is an enlarged partial sectional view showing a gripper of the same device, Fig. 2 (b) is an enlarged partial sectional view showing a modified example of the gripper in the same device, and Fig. 3 is a schematic side view showing a conventional device. , FIG. 4 is an enlarged partial sectional view showing an example of a gripper in a conventional device, and FIG. 5 is an enlarged partial sectional view showing another example of a gripper in a conventional device. 1... Image forming apparatus, 2... Gripper which is a fixing mechanism part, 4.6... Covering member, 21... Thermal printing head which is information recording means, 22... Platen roller which is a carrier. p 29 Figure 1 CG) Figure 2 Figure 3

Claims (2)

[Claims] (1) an image information recording means; a drum-shaped carrier provided opposite to the image information recording means for transporting a recording medium by winding it around its outer circumference; In an image forming apparatus having a fixing mechanism for fixing a recording medium to a carrier, a member equivalent to a member forming an outer periphery of the carrier is arranged in a portion of the fixing mechanism that faces the information recording means. An image forming apparatus characterized by: (2) The image forming apparatus according to claim 1, wherein the member forming the outer periphery of the carrier and the member arranged in the fixing mechanism are elastic bodies.