JPH02121873A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To improve operability and to enhance economical efficiency by housing a transfer material of one color in one winding core pair and providing transfer material having desired colors respectively to a plurality of winding core pairs and making each of the winding core pairs to be selectively and freely movable with respect to a predetermined transfer position. CONSTITUTION:A transfer material supply unit 71 is equipped with a winding core support means 72 for supporting a plurality of winding core paris 84-89 so as to make the same to freely pass with respect to a predetermined position and a replacing and driving means 73 for driving the support means 72 to transfer the selected winding core pair to the predetermined position. By starting the supply of paper, a driving control part 130 rotates a driving body 93 by a predetermined angle through a replacing and driving part 131 according to preset order and opposes the magenta winding core pair 86 to a predetermined position 51a. A press frame 106 advances by the printing order from an upper level device and a thermal head 52 is pressed to the platen drum 51 to perform printing. When printing is finished, the yellow winding pair 87 of the next color is selected and rotated by a predetermined angle to be opposed to the predetermined position 51a. Hereinafter, in the same way, the cyan winding core pair 88 is selected to perform printing and the press frame 106 is retracted to finish printing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to an image forming apparatus suitable for thermal transfer copying machines, color printers, etc. that overlap a plurality of colors.

(Prior Art) Recently, a plurality of colorants (e.g., ink) of a transfer material (e.g., a thermal transfer ribbon) are applied to a recording medium (e.g., paper) supported and transferred by a support and transfer means via a heat-sensitive recording head (e.g., a thermal head). A thermal transfer type image forming apparatus that performs melt transfer to form a desired color image has been developed and has been put into practical use as image forming apparatuses such as thermal transfer copying machines and printers.

FIG. 7 shows an example of an image forming apparatus that has been put to practical use in a thermal transfer copying machine.

Reference numeral 1 denotes a platen drum, which has a cylindrical surface 2 made of an elastic member such as rubber, and is a supporting and conveying means having the same function as a platen roll. It rotates by gripping the tip and wraps the paper P around its outer periphery, and the outer periphery is longer than the length of the paper P. A transfer material supply unit 5 is provided on the left side of the platen drum 1, and a ribbon-shaped transfer material 6 supplied from the unit presses against a predetermined position 7 on the platen drum 1 where transfer is to be performed. ing. Furthermore, a thermal head 8 serving as a heat-sensitive recording medium is provided outside the transfer material 6.

Then, the platen drum 1 around which the paper P is wound is rotated, and the thermal head 8 comes into pressure contact with the platen drum 1 at a predetermined position 7 via the transfer material 6 that runs together with the platen drum 1, so that a desired image is transferred and formed. Normally, this process is repeated three times for each color to form a full-color image with overlapping stamps.

The transfer material supply unit 5 includes a pair of cores 11 and 12, and runs the transfer material 6 while being guided by pinch rollers 13 and 14, from one core 11 to the other core 12.
It is designed to be wound up.

The transfer material 6 is attached to an ink support member 16 as shown in FIG.
Yellow (Y), magenta (M),
It is constructed by sequentially applying cyan (C) and black (B) inks. Then, when transferring each color, the ink portion of the color to be transferred on the transfer material 6 is set in advance to face a predetermined transfer position by a cue operation, and as shown in FIG. 9, for example, the cyan (C) portion is placed on the thermal head. 8, it is heated and melted and transferred.

Therefore, since the ink ribbon was used in a field-sequential manner, it was necessary to locate the beginning of each color, and in the case of an ink ribbon for A4 paper, it could not be applied to A3 paper, or conversely, it could not be applied to A3 paper.
When an ink ribbon for paper is used for A4 paper, half of the ink ribbon is discarded unused, which is uneconomical.

(Problems to be Solved by the Invention) As described above, in the conventional transfer material supply unit, the transfer materials of each color are arranged in a plane-sequential manner, and therefore the operation is poor because the cue is searched for each color. In addition, since it is formed to fit each paper size, it cannot be used for paper larger than the compatible paper, and for smaller paper, some parts are discarded unused, which is uneconomical. There are other inconveniences.

The present invention has been made in order to eliminate the above-mentioned disadvantages, and an object of the present invention is to provide an image forming apparatus having a transfer material supply unit that is easy to operate and has improved economical efficiency.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes: a platen drum that rotates around which a recording medium is wound; a transfer material supply unit that runs a transfer material between a pair of cores and faces the recording medium at a predetermined position; and a thermal recording head that presses and transfers data to the platen drum via a transfer material at the predetermined position, wherein the transfer material supply unit supports a plurality of core pairs so as to be able to pass sequentially to the predetermined position. This image forming apparatus is characterized in that it comprises a core support means for supporting the core, and an exchange drive means for driving the support means and transporting the selected core pair to the predetermined position.

(Function) The present invention accommodates a transfer material of one color in one core pair, provides a transfer material of a desired color by a plurality of core pairs, and places these core pairs at a predetermined location where transfer is to be performed. Since it is selectively movable relative to its position, the transfer material can be replaced in an extremely short time, providing excellent operability.Also, it can handle paper of different sizes without wasting any lengthwise length. It is highly economical because it can be done.

(Example) The details of the present invention will be explained below with reference to an example shown in FIGS. 1 to 6.

In this embodiment, the present invention is applied to a printer section of a thermal transfer copying machine.

FIG. 1 is an overall configuration diagram showing an overview of a thermal transfer type copying machine (hereinafter referred to as a copying machine), and FIG. 2 is a block diagram showing the overall configuration of the copying machine with the control system as the main component.

As shown in FIG. 2, this copying machine includes an overall control section 21, a scanner section 22, a color conversion section 23, a memory section 24, and a printer section 25. Although the details will be described later, green (G) and yellow (Y) detected by the scanner unit 22 are
) and cyan (C) are determined by the color conversion unit 2.
3, the color of the print medium is magenta (M), yellow (
Y) and cyan (C), and the color-converted values are stored in the memory unit 24 for each color together with position information on the document. The printer unit 25 that forms an image prints magenta (M), yellow (Y), cyan (C), and black (B) according to the values read from the memory unit 24.
Black is an AND output of magenta and yellow cyan. A writeable medium, such as a thermal transfer ribbon, is thermally transferred onto a recording medium, such as paper. The overall control section 21 includes the above-mentioned sections 22, 23, and 24.
．． 25 as a whole, but also controls a part of the drive system, which will be described later.

Next, the outline of the scanner section 22 and the printer section 25 in which the present invention is implemented will be explained.

The scanner section 22 is provided at the upper part of the copying machine main body 28, and includes a document table 41, a document cover 42, an optical system 43 for scanning the document, and a photoelectric converter having a light receiving surface on its imaging surface. It is composed of a container 44 and the like. The optical system 43
is equipped with an exposure light source 45 that scans the document from one end to the other while irradiating the document, and the light reflected from the document is
The light is incident on the lens 46 that moves in accordance with the exposure light source 45 by the two reflecting mirrors, and the light that passes through this is imaged by the two reflecting mirrors on the image forming plane, that is, the light receiving surface of the photoelectric converter 44. Then, the GSYSC signal is sent to the color conversion section 23.

Next, the printer section 25 will be explained. This is provided at the bottom of the copying machine main body 28.

51 is a platen drum whose outer peripheral surface is made of an elastic material such as rubber, which also functions as a platen roller for the thermal head 52, and has a gripper 53 on its outer periphery.
It grips the leading end of the paper P as a recording medium to be supplied, rotates by itself, and wraps it around its outer periphery.

The total length of the outer periphery is slightly longer than the length of the maximum applicable paper size in the longitudinal direction. Further, the gripper 53 moves in and out in the radial direction to grip the paper P, but at the gripping position, the tip is located inside the outer periphery of the platen drum 51 and is sunk. This is because the platen drum 51
The thermal head 52 comes into pressure contact with the image, but at this time, if the gripper 53 is protruding outside, the thermal head 52 cannot apply pressure unless the gripper 53 escapes sufficiently, and the non-image area becomes large.

Furthermore, on the outer periphery of the platen drum 51, the paper P
Pressure roller 55, 56, 57, 58 to make the
A belt 59 that runs integrally with the outer periphery of the platen drum 51 is stretched between the pressure rollers 56 and 57 to prevent the paper P from peeling off between the pressure rollers 56 and 57. There is.

A cassette 65 containing stacked sheets of paper P is attached to the lower right side of the platen drum 51, and a pair of paper feed rollers 66
The sheet P sent out by the gripper 53 reaches the pair of registration rollers 67, is registered, and reaches the gripper 53, where its tip is gripped.

On the other hand, on the lower left side of the platen drum 51, a thermal head 52 as the above-mentioned thermal recording head and a transfer material supply unit 71, which is the main part of the present invention, are provided.

The thermal head 52 is similar to a conventional one, so a detailed explanation will be omitted.

The transfer material supply unit 71 includes a core support means 72 , an exchange drive means 73 , a pressing means 74 , and a drive control means 75 .

The core support means 72 will be explained. 80 is a support frame body;
This includes a disk-shaped support plate body 82 having a boss 81, a support ring body 83 consisting of an annular plate body, and ribs 84,...
It is a frame body with the support ring body 83 side open, and the boss 8
It is horizontally supported in a cantilevered manner so as to be rotatable about the axis 84 of 1. Further, eight bearings are mounted on the support plate body 82 and the support ring body 83, facing each other, and the four winding core pairs 86, 87, 88, 89 are equally spaced (at 90 degrees). and is rotatably supported. These core pairs 86-89 are a pair of cores 86a and 86b, respectively.

It consists of winding cores 87a, 87b..., and each core pair has a ribbon-like transfer body 86cs coated with a single colorant.
87c, 88c, and 89c are accommodated, and the winding core 86
a s 87 a =・89 a to core 86b1・・
- Winding up on 89b is the same as the conventional one.

For example, the transfer material 86c1...89c is magenta (CM) for the core pair 86, yellow (Y) for the core pair 87, cyan (C) for the core pair 88, and black B for the core pair 89. is accommodated. These core pairs 86...89 are rotated by gears 86d and 87d.

Drive gears (not shown) mesh with 88d and 89d to perform this operation.

Next, the exchange driving means 73 will be explained. This consists of a frame bracket 91 and a main shaft 9 rotatably supported by the frame bracket 91.
2, a drive body 93 consisting of a motor, a replacement sensor (not shown) that detects the rotation angle of the main shaft 92, and a pair of support rollers 93a that support the support ring 83 of the support frame 80.
, 93b, etc. A boss 81 is fitted into the main shaft 92, and the support frame 80 is cantilevered by the main shaft 92 and rotates integrally with the main shaft 92. Due to the rotation, each core pair 86, . . . It is possible to sequentially pass through the position 51a, that is, the position on the platen 51 where the transfer is performed. Then, when the driving body 93 is rotated by the control means 75 described later, the rotation angle of the support frame body 80 is detected by a replacement sensor, and the rotation is stopped when the set rotation angle is reached. In other words, the selected core pair has been transferred and directly faces the above-mentioned predetermined position.

Next, the pressing means 74 will be explained. This includes a support block 101 having a rectangular cross section.
01 has one end fixed to the pressing bracket 102, extends inside the support frame 8o, and has the other end rotatably fitted to one end of the main shaft 92 and supported. This support block 101 is formed with a flat mounting surface 103 whose upper surface is inclined at approximately 30 degrees with respect to the horizontal plane, and has two spaced apart sliding holes each having a rectangular cross section and a side wall opening in a part of the upper surface. 1゜4.
105 runs parallel to the mounting surface 103 at the predetermined position 51a.
It is placed facing the direction of. In addition, this sliding hole 10
4.105, the press frame 106 is slidably fitted. This pressing frame 106 includes rod-shaped slider parts 107 and 108 that are parallel to each other and have a rectangular cross section, a support part 109 that connects and connects both slider parts 107 and 108, and a support part 109 formed at the tip of both slider parts 107 and 108, respectively. A pair of fork parts 110 and 111 are sharp, and the slider part 107 and 108 has a rack gear 11 on the upper surface.
2.113 is engraved. Furthermore, a pinch roller 115.116 is provided at the tip of the fork portion 110.111.
is rotatably supported, and the support part 109 has a predetermined position 5.
A thermal head (TPH) 52 is attached directly facing 1a.

When the pressing frame 106 slides in the direction of the platen drum 51, the transfer material is pressed against the paper P on the platen drum 51 by pinch rollers 115 and 116, and the thermal head 52 is also pressed into a predetermined position.

On the other hand, when mounting the support block 101, a drive body 120 consisting of a motor is attached to one end of the surface 103, and a drive shaft 121 that transmits the rotation of the drive body 120 is connected to the support block 1-1.
It extends supported by a bearing on 01. This drive shaft 1
21 has binion gears 122 and 123 at the position of the above opening.
is installed, and the above-mentioned rack gears 112, 113
They are engaged. When the drive body 120 is rotated in the direction of the arrow by the control means 75, which will be described later, the pressing frame 106 moves forward via the pinion gears 122 and 123.
Pinch rollers 115, 116 and thermal head 52
As described above, when the platen drum 51 is pressed against a predetermined position and reversed, the press frame 106 retreats, and the pinch rollers 115 and 116 and the thermal head 52 move to a position where there is no problem with the rotation of the support frame 80. evacuate and retreat. Further, the forward and backward movement of the pressing frame 106 is confirmed by a suppression sensor (not shown) attached to the lower end of the sliding hole 104, 105.

Next, the control means 75 will be explained. This includes a drive control section 130 that is connected to the overall control section 21 described above and receives instructions from it, an exchange drive section 131, a press drive section 132, etc. The driving body (motor) 93 of the means 73 is driven, and the pressing driving part (132) is the driving body (motor) of the suppressing means 74.
motor) 120.

Then, when the general control unit 21 instructs the rotation of the support frame 80 (selection of the winding core pair), the pressing sensor confirms that the pressing frame 106 has retreated, and then, as described above, the specified Rotate the support frame 80 to an angle of . Further, in response to a pressing command, the driving body 120 is rotated by a predetermined angle, the pressing frame 106 is advanced to the highest position and stopped, and even when moving back for each color, it is rotated backward by the same angle and the next winding is started. Prepare for the selection command of the heart pair.

As described above, the transfer material supply unit 71 is configured, and its operation will be explained together with the overall operation.

Next, at the upper left of the platen drum 51 is a paper ejection path 140.
is provided. This includes a paper ejection guide 141, a paper ejection roller pair 142, a paper ejection guide 143, and a paper ejection roller pair 144.
, a paper ejection tray 145, etc. After image formation, by counterclockwise rotation of the platen drum 51, the trailing edge of the paper P enters the paper ejection guide 141 and enters the paper ejection tray 145 as shown in FIG. be dropped.

Although this copying machine is constructed as described above, the operation of the printer section 25 will be explained next. First, the paper P taken out from the paper feed cassette 65 passes through a pair of paper feed rollers 66 and is aligned by a pair of registration rollers 67, and then its leading end Pa is gripped by the gripper 53 on the platen drum 51. The same applies to manually fed paper P. The platen drum 51 gripping the paper P rotates clockwise, and printing starts when the gripper 53 passes a predetermined position 151a near print. On the other hand, the transfer material supply unit 71 has previously moved the press frame 106 back to the lowest position and is on standby.

Therefore, as soon as the supply of paper is started, the drive control section 130 controls the exchange drive section 1 in accordance with a preset order.
The driver 93 is driven via the drive member 31 and rotated by a predetermined angle, so that the core pair 86 of, for example, magenta CM) is opposed to the predetermined position 51a. Therefore, when printing is started based on a command from a higher level, the driver 120 is immediately driven, the pressing frame 106 moves forward and stops at the uppermost position, the pinch rollers 115 and 116 press the transfer material 86C, and the thermal head 52 is transferred to the platen drum 51 via the transfer material 86c.
to press. Printing is performed in this state, and immediately after the first printing is completed, the press frame 106 retreats to the lowest position, and the pinch rollers 115 and 116 and the thermal head 52 are retracted from the rotational transport path of the pair of cores. When the press sensor confirms the retraction, the next colorant core pair, for example, yellow (Y) core pair 87, is selected, rotated by a predetermined angle, for example, 90 degrees, and transferred to the yellow (Y) transfer material. 87c faces the predetermined position 51a. Thereafter, in the same manner, for example, the cyan (C) core pair 88 is selected and printed, and the press frame 106 is moved back to complete the printing. After printing is completed, the platen drum 51 further rotates, and when the trailing edge pb of the paper P reaches the position of the paper discharge guide 141, as shown in FIG. 6, the platen drum 51 rotates counterclockwise. As a result, the paper P passes through the paper ejection guide 141 and the paper ejection roller pair 14
When the gripper 53 is released, the paper P is further fed and falls onto the paper discharge tray 145, and copying is completed.

In this embodiment, the winding core pair is arranged on a rotating frame provided outside the platen drum, but the pair of winding cores may be arranged on the circumference around the platen drum, for example. Furthermore, the winding core pair may be attached to a flexible endless conveying body, and the core pair may be guided and conveyed by a guide rail. Further, although the pinch roller and the thermal head are moved back and forth using a gear mechanism, the present invention is not limited to this, and other cam mechanisms, fluid devices, etc. may be used.

〔Effect of the invention〕

As described in detail above, the image forming apparatus of the present invention supports a plurality of core pairs at predetermined positions so as to be able to pass through the core pairs, stores only one color in each of the core pairs, and drives the core pairs to Since a separately selected pair of cores is transported to a predetermined position, the transfer material can be replaced extremely easily, resulting in good operability.Moreover, differences in paper length can be accommodated without waste.
It also has excellent economical effects.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a copying machine to which an embodiment of the present invention is applied, FIG. 2 is a block diagram of the overall configuration of the control system, FIG. 3 is a front view of the above embodiment, and FIG. 4 is the same. I in Figure 3
A cross-sectional view taken along the line V-IV, FIG. 5 is a block diagram of the main parts, FIG. 6 is an explanatory diagram of the operation, FIG. 7 is a configuration diagram of the conventional example, and FIG. 8 is the main part (transfer material). The plan view and FIG. 9 are also perspective views of the main part (transfer material). P... Recording medium, 51... Platen drum, 51a
. . . Predetermined position, 52 . . . Thermal recording head, 71 . . .
- Transfer material supply unit, 72... core support means, 73
... Exchange drive means, 84-89 ... Winding core pair, 86c
~89C...Transfer material

Claims (1)

[Claims] A platen drum that rotates around a recording medium, a transfer material supply unit that runs the transfer material between a pair of cores and faces the recording medium at a predetermined position, and presses the transfer material against the platen drum at the predetermined position via the transfer material. In the device having a thermal recording head for transferring, the transfer material supply unit includes a core support means for supporting a plurality of core pairs so as to pass sequentially through the predetermined positions, and a core support means for driving the support means to select a selected one. an image forming apparatus comprising: exchanging driving means for transporting the core pair to the predetermined position;