JPS6163463A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To make it possible to prevent the generation of printing shift by increasing the printing range of an object to be transferred and smoothing the movement of a transfer material, by forming both end parts of a rotary support from a low friction resistance member. CONSTITUTION:The peripheral speed Vf of feed rollers 21a, 21b is set so as to be made higher than the peripheral speed Vp of a platen roller 5 and the slackening of paper P is removed. The paper P is wound around a platen roller 5 in a non-slackened state between pinch rollers 6a, 6b so as not to impart trouble to the overlapping printing on and after a second color and printing is enabled even before the leading end of the paper P does not reach the side of the pinch roller 6b. When the printing of a first color is finished, the paper P can be separated from thermal transfer paper R and, therefore, the printing of the range from a printing point A to a separation point B is enabled and a printing range is increased. Both end part 5b of the platen roller 5 contacted with the thermal transfer paper R are formed of silicon rubber low in friction resistance and movement can be smoothly performed and, because a wind-up spool 17 is rotatable only to the C-direction, the slackening of the paper P and printing shift are prevented.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to image formation in which a colorant of a transfer material is transferred onto a transfer target supported by a rotating support by driving a print head to form an image. Regarding equipment.

[Technical background of the invention and its problems]

Conventionally, in this type of image forming apparatus, for example, a thermal transfer color printer, as shown in FIG. 91 sheets are taken out one by one, the tips of which are brought into contact with a pair of aligning rollers 3*, 3b, and sent out while being aligned, and guided to the gate 4 shown by the solid line, where it is passed through the platen roller (rotary support) 5 and one entrance. The paper P is conveyed while being pinched between the side pinch rollers 6a, and at this time, a detector 7 provided on the exit side of the aligning rollers 3* and 3b detects the paper P.
By detecting the tip of the solenoid 8 and energizing the solenoid 8, the thermal head (print head) 10' on the holder 9 rotatably attached to the solenoid 8 is rotated clockwise about the shaft 11. , while pressing the thermal head 10 against the platen o-55, deenergizing the solenoid 8 and rotating the thermal head 10 counterclockwise around the shaft 11 as shown in FIG. 6(A) Ic. After the thermal head 10 and the platen roller 5 are brought into a state where they are not in pressure contact, the date 4 is rotated counterclockwise as shown in FIG.
The paper P in between is stretched out and brought into close contact with the platen roller 5.

After bringing the paper Pt into close contact with the platen roller 5, the paper plate 4tP is rotated clockwise to return to its original position, and at the same time, the solenoid 8 is energized again.
As shown in FIG. 6(d), when the thermal head 1θ is in pressure contact with the platen roller 5, the platen roller 5
By driving the paper P, printing is started, and the printed paper P is guided to guides 12a and 12b, and conveyed through the paper discharge roller 13 to the paper discharge tray 14 side, where it can be stacked.

Therefore, in the above device, when overlapping printing is performed on thermal transfer paper (transfer paper) R of different colors, the detector 7
When the trailing edge of the paper P is pinched between the platen roller 5 and the pinch roller 6a by a pulse emitted from the time when the leading edge of the paper P is detected, the thermal head is 10 from the siratin roller 5 so that the paper P and the thermal transfer paper R are not pressed between the platen roller 5 and the thermal head 10, as shown in FIG. The paper P is conveyed in the opposite direction by rotating in the opposite direction, and the gate 4 is further rotated in the counterclockwise direction to guide and convey the paper P so that the trailing edge of the paper P escapes to the pair of id 15a v l5b. When the leading edge of the paper P returns to the state shown in FIG. 6(5), the reverse rotation of the platen roller 5 is stopped, and printing is repeated again in this state, thereby making it possible to perform overlapping printing.

In addition, in order to perform such overlapping printing, it is necessary to use three colors: yellow, magenta, and cyan, or yellow, magenta, and cyan.
Generally, this is done using four colors, cyan and black, and for this reason, as shown in FIG. Guide row 218m, 18b, 18t.

18d, and when the color detector 19 provided near the guide row 218a detects the rear end of the color of the print source, the take-up spool 17, which is driven integrally with the platen roller 5,
It is configured to stop.

However, in the thermal transfer color printer of the conventional structure described above, when cassette paper is used as the paper P, the sixth
As shown in FIG. 7C, the leading edge of the paper P is conveyed and held between the outlet side pinch roller 6b and the platen row 25 during the printing stage, so as shown in FIGS. 7 and 8, Platen row 25 and thermal head IQ
The leading edge of the paper P in the range corresponding to the distance (t1+α) from the printing point A, which is the pressure contact point, to the pinch roller 6b, and the distance mCtx+α) from the printing point A to the pinch roller 26a)
The trailing edge of the paper P in the range corresponding to the sum (21+α+ts) of the distance t from the printing point A to the separation point B between the thermal transfer paper R and the paper P cannot be printed, and for example, on A4 size paper P. For the total length of 297mm, the tip part P1 is 25w and the rear end P3 is about 45w and cannot be printed, and the printing range P2 between them is about 227vm, which is extremely short.
There is a problem.

Furthermore, conventionally, f Latin CI -, r
5 is made of a material that has a high coefficient of friction against the paper P, such as urethane rubber, but this platen row 25 has the entire circumferential surface made of urethane rubber, so it can easily hold the paper P. It also acts on the thermal transfer paper R protruding from P, and as shown in FIG. There was a problem in that the large resistance hindered the movement of the thermal transfer paper R and caused printing misalignment.

[Purpose of the invention]

This invention was made under the above-mentioned circumstances, and it is possible to greatly increase the printing range of the transfer target with a relatively simple structure, and also prevents the occurrence of printing misalignment by smoothing the movement of the transfer material. The object of the present invention is to provide an image forming apparatus that can perform the following operations.

[Key points of invention]

In order to achieve the above-mentioned object, the present invention drives a print head through a transfer material on a rotary support body on which a transfer object is transferred, and transfers the colorant of the transfer material onto the transfer object. The image forming apparatus is characterized in that both ends of the rotary support are formed of low frictional resistance members with respect to the transfer material.

[Embodiments of the invention]

The present invention will be described below with reference to an embodiment shown in FIGS. 1 to 4. In the illustrated embodiment of the present invention, the same reference numerals are used for the same parts as those of the conventional structure shown in FIGS. 5 to 9, and the explanation thereof will be omitted.

That is, as shown in FIG.
A pair of conveyance rollers 21h and 21b are provided on the downstream side in the transfer conveyance direction of the paper P from the print point A at 0, and the conveyance rollers 21h and 21b are provided to pinch and convey the paper P detached from the circumferential surface of the grating roller 5, and the conveyance rollers 221a, The circumferential speed V of the platen roller 5 is set to be faster than the circumferential speed V of the platen roller 5, and a pair of pinch rollers 6m and 6b, which press against the platen roller 5 to pinch and convey the paper P, are set to be faster than the circumferential speed V of the platen roller 5. The conveying roller 2c has a configuration that can be detached from the roller 5.

21b is the platen roller 25 when printing is started with the pinch roller 6b separated from the platen roller 25.
) 6b and the platen roller 5 to absorb the deflection of the paper P by pinching and transporting the leading end side of the paper P transported by 50 rotations, and pinching the leading end of the paper P to the platen roller 5.
Printing on the paper P becomes possible before reaching the rolling contact portion with the paper P. Then, the platen roller 5
The lensoid 8 that operates the thermal head 1θ so as to be able to approach and separate from the thermal head 10 moves the guide rollers 18b and 18c of the thermal transfer paper R along the movement direction of the thermal head 10, respectively, in conjunction with the movement of the thermal head 10. It has such a configuration and enables separation between the paper P and the thermal transfer paper R. Furthermore, the take-up spool 17 that winds up and stores the thermal transfer paper R rotates only in the winding direction of direction C shown in FIG. Furthermore, as shown in FIG. 2, the platen row 25 has a central portion 5a, which corresponds to the portion where the paper P is wound, made of a material with a high friction coefficient such as urethane rubber. A material having
Both ends sb, sb are formed of a low friction resistance material against the thermal transfer paper R such as silicone rubber, and the thermal transfer paper R that protrudes from the paper P during printing is located at both ends 5b, Sb side of the platen row 25. The movement resistance when contacting the surface is reduced.

Therefore, the operation of the present invention having the above-mentioned configuration can be explained in a third manner.
4 and 4. First, the pinch roller 6a is pressed against the platen row 25 to convey the paper P, and as shown in FIG. is also stopped at a position where it has been conveyed by a length t. Next, the pinch roller 6a is removed from the platen row 25, and the sheet Pf is rotated in the direction of the solid line arrow in the third figure) to tension the paper Pf and remove its deflection, and then the pinch row 26a is removed again. The printer is brought into pressure contact with the platen roller 5, and the platen roller 5 and take-up spool 17 are driven to start the printing operation. At this time, printing on the paper P starts at a distance t from the leading edge of the paper P, and as the platen row 25 rotates, the paper P is printed as shown in FIG.
) is separated from the thermal transfer paper R at the separation point B shown in FIG. It bends, and as a result, the printing point A
When the L paper PK is bent on the latter side in the transfer conveyance direction after passing through the 1st color, and when the first color printing is completed and the paper P is reversed to perform the second color 1st printing, the paper P becomes skewed and bent. Since printing misalignment occurs when overlapping printing is performed after two colors, the leading edge of the paper P that has passed through the black printing area is moved to the transport roller 21a.

Once clamped by 21b, the transport row 221a.

The peripheral speed V of 21b is the peripheral speed V of the platen row 25.

Since the speed is set faster, tension is generated during this time, and the bending of the paper P is removed. and,
During this time, the pinch roller 6b is separated from the platen roller 5, and after the deflection of the paper P is removed, it is brought into pressure contact with the platen opening roller 5 again, and the paper P is moved between the pinch rollers 6h and 6b. It is wound around the platen row 25 in a state without bending so that it does not interfere with overprinting of the second and subsequent colors, and as a result, the leading edge of the paper P does not reach the pinch roller 6b. This makes it possible to start printing, and the unprintable portion on the leading edge side of the paper P is only the distance t, greatly increasing the printing range.

As shown in FIG. 3(C), when the printing operation of the first color is completed, the solenoid 8 is deenergized and the thermal head 1
0. Since the paper P can be completely separated from the thermal transfer paper R by separating the guide rollers 18b and 1ljc from the grating roller 5, the length t from printing point A to separation point B can be
Area B (see Figures 7 and 8) can be printed.
Therefore, the length of the unprintable area at the rear end of paper P is t,
+α), and the printing range on the trailing edge side of the paper can also be increased.

Next, in order to perform the 1" manual operation for the second color, move the leading edge of the paper P to the printing point A in the same way as when starting printing for the first color described above.
The paper P and thermal transfer paper R are moved a little towards the grating roller 5 side by a small angle θ. By keeping the thermal head 1O1 in a wrapped state, the thermal head 1O1 guide rod is prevented from being messed up as shown in Figure 3(b) by a dot @ line. The first printing jib, 18c is moved to the platen roller side by the energization of the solenoid 8, and the printing operation for the second color is started.In this case, the thermal head 1θ,
Guide roller 18b.

11Jc, the length of the thermal transfer paper R stretched between the guide rows 218a, e, I, and d becomes longer than the length before the movement, as shown in FIG. The thermal transfer paper R will move by the amount of draw (Ll - Ll), but as shown in FIG. Since it is made of silicone rubber or the like with low resistance, it can be moved smoothly.The winding lithbour 12 that winds up and stores the thermal transfer paper R is indicated by the solid line arrow in Fig. 3 (G). The thermal head 10 does not rotate in the reverse direction shown by H, but can rotate only in the C direction shown in FIG. When the head 10 etc. moves, the thermal transfer paper Rf! : Moved from the feeding side to the winding side to prevent the occurrence of sagging of the paper P and eliminate printing misalignment.

Note that the present invention is not limited to the above-mentioned embodiment, and can be applied to, for example, a monochrome image forming apparatus, and the conveying rollers 21* and 21b, which are conveying means, are used to transport the transferred object externally after the transfer is completed. It is also possible to reduce the size of the entire apparatus by using it also as a paper discharging means for discharging paper.

In addition, it goes without saying that this invention can be modified in various ways without departing from the gist of the invention.

〔Effect of the invention〕

As explained above, according to the present invention, although the configuration is relatively simple, it is possible to increase the transfer range to the transfer target and prevent skew conveyance of the transfer target to eliminate printing misalignment. It has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an embodiment of an image forming apparatus according to the present invention, FIG. 2 is an explanatory diagram of a rotating support body,
Figure 3 (B) (C) ρ (2) Prompt) is an explanatory diagram showing the operating state, Figure 4 is an explanatory diagram showing the remaining transfer range to the object to be transferred, and Figure 5 is an explanatory diagram of the conventional image forming apparatus. Schematic explanatory diagram, Figure 6 B)
8 and 8 are explanatory diagrams showing a transfer range to a transfer target, and FIG. 9 is an explanatory diagram of a conventional rotating support. 5...Rotating support (platen row 2), 5a...Middle large portion, 5b...Both ends, 10...Print head (thermal head), 20...Transfer part, P...Target Transcript (
paper), R...transfer material (thermal transfer paper). Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 (A) CB) (C) Figure 3 (D) CF) Figure 4 fJ6

Claims (2)

[Claims] (1) In an image forming apparatus that forms an image by driving a print head via a transfer material onto a rotating support body to which a transfer object is transferred, and transfers a colorant of the transfer material onto the transfer object, the image forming apparatus includes: An image forming apparatus characterized in that both ends of the rotating support are formed of low frictional resistance members with respect to the transfer material. (2) The image forming apparatus according to claim 1, wherein both ends of the rotating support are made of silicone rubber.