JPH02182476A - Apparatus for formation of image - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is used, for example, as a thermal printer that forms an image on an image forming medium by thermally transferring a coloring material of a transfer material. The present invention relates to an image forming apparatus.

(Prior Art) In a conventional thermal printer (image forming apparatus), paper as an image forming medium is wound around a platen drum, and a thermal head is applied to the paper wound around this drum via a thermal transfer ribbon (transfer material). Let them come into contact with you. Then, by driving the heating element of this thermal head according to the image information and moving the paper and the thermal transfer ribbon in synchronization, the image information is transferred onto the paper using the ink (coloring material) of the thermal transfer ribbon. An image corresponding to the image is formed.

This type of thermal printer uses colored thermal transfer ribbons for each ink (for example, yellow (Y),
By changing the three colors (magenta (M), cyan (C), and these four colors plus black (BL)) and layering these in order, a multicolor full-color image can be obtained. . In this case, an image for one color is formed by moving the paper equivalent to one rotation of the drum, so each time a color is formed, the platen drum is rotated in the opposite direction to that used for image formation, and the leading edge of the paper is rotated. There is a method in which the ribbon is pulled back to the image formation start position, and the ribbon is fed so that the leading edge of the next ink corresponds to the leading edge position of the paper (image formation start position). Two methods are generally used: one is to send the leading edge of the ribbon to the image forming start position, and the other is to feed the ribbon so that the leading edge of the next ink corresponds to the leading edge position of the paper.

However, normally with thermal printers like the one mentioned above,
In order to be able to form images on sheets of various sizes, the diameter of the platen drum is set such that a sheet of maximum size on which images can be formed can be wrapped around it. Furthermore, each ink portion (coloring material layer) of the thermal transfer ribbon is also the same size as the maximum size paper on which an image can be formed in the printer. Therefore, in the case of a method in which the platen drum is rotated in the opposite direction to that during image formation and the leading edge of the paper is pulled back to the image forming start position, the leading edge of the largest size paper that makes maximum use of the platen drum and thermal transfer ribbon can be used. It took a long time to return to the image formation starting position. On the other hand, if the paper is rotated in the same direction as the image is being formed and the leading edge of the paper is sent to the image formation start position, the paper must be of the smallest size on which the image can be formed (for example, the paper size is half of the outer circumference of the platen drum). paper that does not meet the requirements)
It took a long time to send the leading end of the image forming apparatus to the image forming start position.

(Problems to be Solved by the Invention) As described above, in the conventional apparatus, each time image formation for one color is completed, the leading edge of the paper and the leading edge of the next ink of the ribbon are moved to the image forming start position. The disadvantage is that it takes time to perform the operation to accommodate the above, making it impossible to increase the speed.

Therefore, the present invention can shorten the time required for the operation to align the leading edge of the image forming medium and the leading edge of the next coloring material of the transfer material with the image forming start position, thereby increasing speed. The purpose of this invention is to provide an image forming apparatus with a high level of functionality.

[Structure of the Invention] (Means for Solving the Problems) The image forming apparatus of the present invention includes a thermal head having a large number of heating elements, and a coloring material layer that is approximately equal in size to the image forming medium. a platen drum whose periphery is approximately equal in size to the size of the image forming medium, and a transport path that guides the image forming medium to the platen drum; A forming medium is wound around the platen drum, the thermal head is brought into contact with the image forming medium wound around the drum via the transfer material, and this thermal head is driven according to image information, and the image forming medium is wound around the platen drum. In the device for forming an image according to the image information on the image forming medium using the coloring material of the transfer material by moving the forming medium and the transfer material in synchronization, the transfer material and the platen drum are moved. A plurality of image forming means provided as a pair according to image forming media of different sizes, a detecting means for detecting the size of the image forming medium, and a size of the image forming medium detected by the detecting means. and switching means for switching a conveyance path for guiding the image forming medium to one of the image forming means according to the image forming means.

(Function) According to the above-described means, a plurality of platen drums and transfer materials are prepared for each size of the image forming medium, and these are used properly according to the size of the image forming medium. It is something.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows, as an example of the image forming apparatus of the present invention, a thermal transfer type color copying machine capable of forming multicolor images. That is, 1 is a main body of a copying machine, and an operation panel is provided at the front of the upper surface of the main body 1. The upper part of the main body 1 is a document scanning section 3 that scans and reads a document set on a document table (transparent glass) 2, and the lower part is an image forming section 4. Note that 5 is a document cover provided on the document table 2 so as to be openable and closable. Further, the document table 2 is fixed to the main body 1.

The document scanning unit 3 includes, for example, a first carriage 7 provided with an illumination lamp 6 as a light source, a second carriage 8 that bends the optical path with a mirror, a zoom lens 9, which corrects the optical path length when changing the magnification, and scans the document. The mirror part 10 guides reflected light from the original to a photoelectric converter, a photoelectric converter 11 receives reflected light from the original, and a drive system (not shown) changes the positions of these parts.

The first carriage 7 includes an illumination lamp 6 that irradiates light onto the document, a glue deflector 12 that serves as a reflector that collects the light from the illumination lamp 6 onto the surface of the document, and a second carriage 8 that directs the light reflected from the document. A mirror 13 that guides the camera to the side is mounted.

The second carriage 8 includes a mirror 8a that guides the light guided by the mirror 13 to the zoom lens 9.

8b is installed. Above 1. 2nd carriage7.
8 are connected to each other by a timing belt (not shown), and the second carriage 8 is connected to one of the first carriages 7.
They move in the same direction at a speed of /2. This makes it possible to scan so that the optical path length up to the zoom lens 9 is constant.

The zoom lens 9 has a fixed focal length and is moved in the optical axis direction when changing the magnification.

The mirror portion 10 includes two mirrors 10a.

10b and selected magnification (copy magnification)
Those mirrors 10a change according to the change in the optical path length corresponding to
, 10b are changed, and the light from the zoom lens 9 is guided to the photoelectric converter 11 by bending the optical path with the two mirrors 10a and 10b.

The photoelectric converter 11 photoelectrically converts the light reflected from the original, thereby separating and outputting the image of the original as cyan, green, and yellow (or red, green, and blue) light color signals. It is mainly composed of a beline image sensor. In this case, one pixel of the original is detected by three consecutive elements (C, GS,
Y) is supported. The output of the photoelectric converter 11 is
Digital processing is performed in a photoelectric conversion section, which will be described later.

Above 1. The second carriage 7.8, zoom lens 9, and mirrors 10a and 10b are moved by stepping motors (not shown), respectively.

On the other hand, the image forming section 4 includes a plurality of (first...
A second) image forming means 33.50 is provided. This first. The second image forming means 33.50 includes, for example, the first image forming means 33.50. The second paper size is formed according to each of the first paper size.
．． The second image forming means 33.50 also has a similar configuration.

That is, the platen drum 22 constituting the image forming means 33 of Arithmetic 1 is made of an elastic material such as rubber around the platen drum 22 and has a function as a platen roller of the thermal head 24. The platen drum 22 rotates itself counterclockwise to wrap the paper around it, thereby preventing the paper from shifting during overlapping printing. One point on the platen drum 22 (in the cylindrical (width) direction of the drum 22)
is provided with a gripper 23 that clamps and fixes the leading edge of the paper, and around the gripper 23 the paper is held at predetermined intervals on the platen drum 2.
Pressure roller 25 to prevent floating from 2.・
... is provided. The circumference of the platen drum 22 is slightly longer than the length of the first paper size in the longitudinal direction.

A thermal head 2 is located on the left side of the platen drum 22.
4 are arranged. The thermal head 24 is formed into a claw tube with a heat radiator integrally formed on the rear end surface of the holder.

An ink ribbon (thermal transfer ribbon) as a transfer material is provided between the platen drum 22 and the thermal head 24.
26 is present.

The ink ribbon 26 has three colors, for example, yellow (Y), magenta (M), and cyan (C), or yellow,
Ink layers (color material layers) of four colors, magenta, cyan, and black (BL), are arranged sequentially in the longitudinal direction of the film base. The size of each of the ink layers is approximately equal to the first paper size.

Core 30.3 around which the ink ribbon 26 is wound
1 is connected to a drive shaft of a motor (not shown) via a drive force transmission mechanism (not shown), and is rotated as required.

A platen drum 52 constituting the second image forming means 50
The periphery of the roller is made of an elastic material such as rubber, and functions as a platen roller for the thermal head 54. The platen drum 52 rotates itself counterclockwise to wrap the paper, thereby preventing the paper from shifting during overlapping printing. A gripper 53 is provided at one point of the platen drum 52 (in the cylindrical (width) direction of the drum 22) to grip and fix the leading edge of the paper, and around the gripper 53 is provided at predetermined intervals to prevent the paper from floating up from the platen drum 52. Pressure rollers 55, . The circumference of the platen drum 52 is slightly longer than the length of the second paper size in the longitudinal direction.

Here, the first paper or the second paper is a paper of a relatively frequently used size, such as A4 size paper and 85 size paper.

A thermal head 5 is located on the left side of the platen drum 52.
4 are arranged. The thermal head 54 is attached to a heat radiator integrally formed on the rear end surface of the holder.

An ink ribbon (thermal transfer ribbon) as a transfer material is provided between the platen drum 52 and the thermal head 54.
56 is present.

The ink ribbon 56 has three colors, for example, yellow (Y), magenta (M), and cyan (C), or yellow,
Ink layers (color material layers) of four colors, magenta, cyan, and black (BL), are arranged sequentially in the longitudinal direction of the film base. The size of each of the ink layers is approximately equal to the second paper size.

Core 60.6 around which the ink ribbon 56 is wound
1 is connected to a drive shaft of a motor (not shown) via a drive force transmission mechanism (not shown), and is rotated as required.

A paper feed roller 41 is provided at the lower portion of the main body 1, and is adapted to take out sheets P, which serve as image forming media, stored in the paper feed cassette 20 one by one.

Here, the paper feed cassette 20 is detachable from the side of the main body 1. The paper P taken out by the paper feed roller 41 is
The registration roller 21 is disposed diagonally below the left of the platen drum 22 by the conveyance roller 42, or the registration roller 5 is disposed diagonally below the left of the platen drum 52.
1 and its tip alignment is performed.

In this case, the first sheet is conveyed through the conveyance path 43 to the registration rollers 21, and the second sheet is conveyed through the switching gate (switching means).
44, the registration roller 5 is conveyed through the conveyance path 43.
1 respectively.

After that, the first sheet is transferred toward the platen drum 22 by the registration rollers 21, and the gripper 23 and the pressing roller 25. ...by platen drum 22
The material is wound around the material, which allows it to be fed accurately. Further, the second sheet is transferred toward the platen drum 52 by the registration roller 51, and the gripper 53 and the pressing roller 55. ...by platen drum 52
The material is wound around the material, which allows it to be fed accurately.

Note that the paper P fed from the manual paper feeder 46 is also wound around the platen drum 22 or 5214 in the same manner as described above.

Paper P whose leading end is fixed by the above gripper 23.53
are wound around the platen drum 22.52 by counterclockwise rotation, and after the leading edge passes through the printing area, the thermal head 24.54 wraps around the platen drum 22.5.
2, and printing is thereby performed.

When printing of the first color on the paper P sent to the printing area is completed as described above, the platen drum 22.
52 has made almost one revolution. Then, the thermal head 24.54 is released once, and the ink ribbon 2
6.56 is wound up and the next color is cued up. In this case, the circumference of the platen drum 22.52 is approximately the same as the length in the longitudinal direction of the first paper size or the second paper size, and the ink ribbon 22.
．． 56, each ink layer has the same size as the first paper or the second paper.

Therefore, printing of the next (second color) can be started immediately upon completion of printing of the -th color.

Then, the platen drum 22 starts rotating counterclockwise again, printing is performed by the thermal printer 24, and the next color is printed (printed) in an overlapping manner.

In this way, in the case of full-color copying, a multicolor image is formed by four operations of yellow, magenta, cyan, and black, or three operations of yellow, magenta, and cyan. Note that in the case of a single color, this is performed in one operation.

When discharging the paper P on which the image has been formed in this way, the paper P is held until the trailing edge of the paper P reaches the paper discharging guide 27.57.
The platen drum 22.52 is rotated counterclockwise. When the rear end of the paper P reaches the paper ejection guide 27.57, by rotating the platen drum 22.52 clockwise, the rear end of the paper P is separated from the platen drum 22.52 by a separating pawl (not shown). The paper is separated and guided to the paper discharge guide 27.57. Also, gripper 23.5
3 passes through the transfer section, the leading end of the paper P is released from the gripper 23.53 by engaging the gripper 23.53 with a gripper release pawl (not shown), for example. Then, the leading edge of the paper P is at the gripper 23.53.
The sheet P, which has been copied and released from the sheet discharge guide 27.57, is sent to two pairs of remelting rollers.
By passing through this, the ink on the paper P is remelted and permeated, and then is discharged onto the paper discharge tray 28.

FIG. 2 schematically shows the overall control system. That is, the main control section 100 is mainly composed of, for example, a CPU (central processing unit) and its peripheral circuits, and includes a pass line 10.
1 is connected. The pass line 101 includes an operation panel 200 of the copying machine main body 1, a display control circuit 103 that controls the operation panel 200, a storage section 104, a scanner control section 105 that controls the document scanning section 3, and the photoelectric converter 1.
a photoelectric conversion unit 106 that performs digital processing on the output of 1;
A color conversion unit 107, a color separation unit 108, a transfer control unit 109 that controls the distribution gate 44, a thermal head first drive unit 110 that drives the thermal head 24, and a thermal head that controls the temperature of the thermal head 24. A first temperature control section 111 , a paper conveyance position first detection section 112 that detects the conveyance position of the first sheet, and a core 30 of the ink ribbon 26
．． a thermal transfer ribbon first drive circuit 113 that drives the thermal transfer ribbon 31; a thermal head second drive section 210 that drives the thermal head 54; a thermal head second temperature control section 211 that controls the temperature of the thermal head 54; Detecting paper conveyance position second detection unit 222, ink ribbon 5
A second thermal transfer ribbon drive circuit 223 that drives the winding cores 60 and 61 of No. 6, and a paper size detector 201 that detects the paper size are connected to each other.

The display control circuit 103 operates in response to a signal sent from the main control section 100 via the pass line 101, and controls a display (not shown) provided on the operation panel 200. Furthermore, input signals from keys operated on the operation panel 200 are supplied to the main control section 100 via the pass line 101, and control is performed in response to these signals.

The storage unit 104 stores data from the main control unit 100 to the pass line 101.
The path line 10 operates in response to a signal sent through the pass line 10
1, or reads out the stored information.

The scanner control section 105 operates in response to a signal sent from the main control section 100 via the pass line 101, and controls the illumination lamp 6 and drive system (not shown) of the first carriage 7, and the photoelectric conversion section 106. control each.

The light 7 converting unit 106 detects an image on the document according to a signal sent from the main control unit 100 via the pass line 101, and outputs a digitized light color signal.

The color conversion unit 107 converts the color signal of the light output from the photoelectric conversion unit 106 into yellow, magenta, and cyan.

It is converted into color signals of each black ink, and these color signals are output to the pass line 101.

The two-color separation unit 108 converts the light color signal output from the photoelectric conversion unit 106 into, for example, black and red ink color signals, and is used when the original image is composed of two colors such as black and red. Used when This two-color separation section 10
The output signal of 8 is output to the pass line 101. The two-color separation section 108 and the color conversion section 107 can also perform color conversion on the signal sent from the pass line 101 and output a new signal to the pass line 101.

The conveyance control unit 109 receives the pass line 1 from the main control unit 100.
01, the platen drive motor drives the platen drum 22, 52, the paper feed roller 41, the registration rollers 21, 51, etc., and the gate 44 etc. for distribution. The driving solenoids (none of which are shown) are selectively switched and driven.

The first thermal head driving section 110 operates in response to a signal sent from the main control section 100 via the pass line 101 and a signal from the first thermal head temperature control section 111, and controls the heating element ( drive and control the heating element). The thermal head first temperature control section 111 outputs a temperature control signal to the thermal head first drive #110 in response to a signal sent from the main control section 100 via the pass line 101.

The paper conveyance position first detection unit 112 detects the conveyance position of the first paper (conveyance amount from paper feeding) by counting the number of drive pulses of a transport system motor (not shown) from the time when the first paper starts being fed. It is something to do.

The thermal transfer ribbon first drive circuit 113 controls a ribbon drive motor (not shown) that drives the winding core 30° 31 of the ink ribbon 26 in synchronization with the position signal of the first paper P supplied from the main control unit 100. This is to drive the ink ribbon 26.

The thermal hept second drive unit 210 operates in response to a signal sent from the main control unit 100 via the pass line 101 and a signal from the thermal head second temperature control unit 211, drive and control the body). The thermal head second temperature control section 211 outputs a temperature control signal to the thermal head second drive section 210 in response to a signal sent from the main control section 100 via the pass line 101.

The paper conveyance position second detection unit 222 detects the conveyance position of the second paper (conveyance amount from paper feeding) by counting the number of drive pulses of a transport system motor (not shown) from the start of paper feeding of the second paper. It is something to do.

The thermal transfer ribbon second drive circuit 223 controls a ribbon drive motor (not shown) that drives the winding core 60° 61 of the ink ribbon 56 in synchronization with the position signal of the second paper P supplied from the main control unit 100. This is to drive the ink ribbon 56.

The main control unit 100 also monitors the output (on/off) from the paper size detector 201 at predetermined time intervals, and counts the time from when the detector 201 is turned off to when it is turned on. Or the paper transport position section 1 above. The paper size is detected by counting the conveyance amount of the paper by the second detection unit 112, 222. Then, the main control section 100 determines the range in which image formation is to be performed according to the detected paper size, and based on this determination, the transport control section 109, the thermal head first .
The second drive unit 110, 210, the first thermal head. Second
Temperature control section 111, 211, thermal transfer ribbon first. The second drive circuit 113, 223, storage unit 104, and the like are controlled to perform an image forming operation on the first paper or the second paper.

Next, the operation in the above configuration will be explained.

For example, assume that a start key (not shown) on the operation panel 200 is operated. Then, the main controller 100 controls the transport controller 109 to operate the paper feed roller 41 and the like, and takes out the paper P from the paper feed cassette 20. At this time, the paper P taken out is detected by the paper size detector 201.
Its size is detected by

When the result from the paper size detector 201 is supplied, the main control unit 100 switches the gate 44 for sorting based on the size of the paper P. That is, if it is determined that the paper P is the first paper, the sorting is done at the gate 44.
is set to the state shown by the solid line in the figure, and is sent to the registration roller 21 on the first image forming means 33 side. If it is determined that the paper is the second paper, the gate 44 is set to the state shown by the broken line in the figure, and the paper is sent to the registration roller 51 on the second image forming means 50 side.

In this way, the first paper sent to the registration roller 21 is wound around the platen drum 22, and the thermal head 24
At the position (image formation start position), the ink ribbon 2
6, the thermal head 24 is driven in accordance with each color signal, whereby printing is performed in order from the first color. In this case, the outer periphery of the platen drum 22,
Each ink portion of the ink ribbon 26 is approximately the same size as the first paper size. For this reason, the platen drum 2
Image formation (printing) for one rotation of 2, that is, one color
At the end of the operation, the leading edge of the first sheet and the ink portion corresponding to the next color are already aligned.

Therefore, when image formation for one color is completed,
The image forming operation for the next color can be started immediately.

On the other hand, similarly to the first paper P, the size of the second paper P is approximately the same as the outer periphery of the platen drum 52 and each ink portion of the ink ribbon 56. Therefore, each time one color is formed, the next forming operation can be started immediately.

As described above, a plurality of sets of platen drums and ink ribbons are prepared to match the various paper sizes on which images are formed, and these are used appropriately depending on the paper size.

In other words, the platen drum and ink ribbon are configured to suit various paper sizes so that printing for exactly one color can be completed with one revolution of the platen drum, without having to perform a cueing operation for the paper or ribbon. , so that the next printing can be started immediately. Thereby, the time required for cueing operation can be shortened or omitted. Therefore, it is possible to increase the speed, which is particularly useful when forming a multicolor full-color image by overlapping.

In the above embodiment, two types of paper sizes have been described, the first paper (A4 size) and the second paper (85 size), but the present invention is not limited to this. The present invention can be applied to various paper sizes by configuring a platen drum and an ink ribbon that match the paper size, either in addition to or in addition to the first paper and the second paper.

It goes without saying that various other modifications can be made without departing from the gist of the invention.

[Effects of the Invention] As detailed above, according to the present invention, the time required for the operation to align the leading edge of the image forming medium and the leading edge of the next coloring material of the transfer material with the image forming start position can be reduced. Accordingly, it is possible to provide an image forming apparatus capable of increasing speed.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a sectional view schematically showing the overall configuration, and FIG. 2 is a block diagram schematically showing the overall control system. 1... Copying machine body (image forming device) 22°52...
・Platen drum, 24.54...-thermal head,
26.56... Ink ribbon (transfer material) 33.50.
. . . Image forming means, 43 . . . Transport path, 44 . . . Distribution gate, 100 . Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Scope of Claims] A thermal head having a large number of heating elements; a transfer material having a coloring material layer approximately equal to the size of the image forming medium; and a periphery thereof having approximately the same size as the image forming medium. the platen drum, and a conveyance path that guides the image forming medium to the platen drum, the image forming medium guided by the conveyance path is wound around the platen drum, and the image forming medium is wound around the drum. The thermal head is brought into contact with the transfer material through the transfer material, the thermal head is driven according to image information, and the image forming medium and the transfer material are moved in synchronization. In an image forming apparatus that forms an image according to the image information on the image forming medium using a coloring material, the transfer material and the platen drum are used as a pair, and a plurality of platen drums are provided according to image forming media of different sizes. an image forming means, a detecting means for detecting the size of the image forming medium, and a method for transferring the image forming medium to one of the image forming means according to the size of the image forming medium detected by the detecting means. An image forming apparatus comprising: switching means for switching a conveyance path for guiding.