JPH0524355A - Image forming device - Google Patents

Abstract

(57) [Summary] [Object] The present invention provides an image forming apparatus capable of forming an excellent image even when the sizes of the image forming medium and the transfer medium are different. According to the present invention, a first transporting means 71 for transporting a plurality of types of image forming media having different sizes, a second transporting means 72 for transporting a plurality of types of transfer members having different sizes, and a transfer member as an image. Recording means for bringing the transfer medium of the transfer member into contact with the forming medium and transferring the transferred medium to the image forming medium to form an image, the first detecting means for detecting the size of the image forming medium, and the transfer medium. Of the image forming medium and the transfer medium according to the smaller one of the size of the image forming medium and the size of the transfer medium based on the detection results of the second detecting unit and the detecting results of both the detecting units. And a control means 100 for setting. As a result, even if the sizes of the image forming medium and the transfer medium do not match, the image forming operation matching the smaller size is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus.

[0002]

2. Description of the Related Art In a conventional image forming apparatus, when forming an image on a sheet wound around a platen drum,
A single ink ribbon arranged between the thermal head and the paper is impregnated with a plurality of colors of Y, M, C, K4 colors or Y, M, C3 colors, and each ink of this ink ribbon is applied to the paper. On the other hand, images are formed by sequentially transferring one color at a time.

In some image forming apparatuses, a plurality of types of ink on the ink ribbon are prepared in accordance with the size of paper for the purpose of saving the ink ribbon and shortening the printing time.

By the way, it is desirable that the kind of ink ribbon and the kind (size) of the paper are the same when transferring to the paper. However, due to forgetting to replace the ink ribbon container or the paper, a situation may occur in which the types of the ink ribbon and the paper do not match.

In such a case, in the conventional apparatus, in a situation where the types of the ink ribbon and the paper do not match, the paper feed amount, the ink ribbon feed amount, the transfer time, etc. are determined depending on one of the two types. Was there.

As a result, the conventional device has the following problem.

(1) First, when the paper is smaller than the ink ribbon and the transfer is performed in conformity with the paper, the image is printed on the full paper and no problem occurs in the image.

On the other hand, if the transfer is carried out in conformity with the ink ribbon, the transfer will continue even after the paper has been conveyed, so that
Ink will be transferred onto the platen drum. If the data is transferred onto the platen drum, there is a problem that the back side of the paper becomes dirty at the time of transfer to the next paper, or ink on the platen drum causes a paper detection error during the transfer operation. ..

(2) Next, when the paper is larger than the ink ribbon, if the transfer is performed in conformity with the ink ribbon, the image forming range is limited to the range of the ink ribbon, but no particular problem occurs.

On the other hand, if the transfer is performed in accordance with the paper, the transfer is continued even after the ink ribbon has been fed, so that the transfer is performed across the area of the ink ribbon of the next color. Then, for example, only the yellow (yellow) ink should be transferred originally, but the magenta ink is transferred from the middle, so that good image formation cannot be performed.

Considering the above situation,
In the case of (1), it should be transferred according to the paper, and (2)
In the case of, it should be transferred according to the ink ribbon.
In other words, it should be transferred according to either the paper or the ink ribbon, whichever is “larger”.

[0012]

[Problems to be Solved by the Invention] As described above,
If you forget to replace the ink ribbon container or paper,
In the conventional apparatus, since the image forming operation is executed depending on one of the ink ribbon and the paper, there is a problem that a good image cannot often be formed.

Therefore, it is an object of the present invention to provide an image forming apparatus capable of forming an excellent image even when the sizes of the image forming medium and the transfer medium do not match. ..

[0014]

According to the present invention, there are provided a first conveying means for conveying a plurality of types of image forming media having different sizes and a second conveying means for conveying a plurality of types of transfer members having different sizes.
And a transfer member conveyed by the second conveying means are brought into contact with the image forming medium conveyed by the first conveying means to transfer the transfer medium of the transfer member onto the image forming medium. In an image forming apparatus including a recording unit for forming an image, a first detecting unit for detecting a size of the image forming medium conveyed by a first conveying unit and a second conveying unit for conveying the image forming medium. A second detection unit that detects the size of the transfer medium; and a smaller size of the image formation medium size and the transfer medium size that is extracted based on the detection results of the first and second detection units.
And a control unit for setting the carry amount of the image forming medium by the first carrying unit and the carry amount of the transfer medium by the second carrying unit according to the extracted size.

[0015]

The operation of the image forming apparatus having the above-mentioned structure will be described below.

When forming an image on the image forming medium by this image forming apparatus, the first detecting means is the first detecting means.
The size of the image forming medium conveyed by the conveying means is detected, and the detection result is sent to the control means. The second detection means detects the size of the transfer medium conveyed by the second conveyance means, and sends the detection result to the control means.

The control means extracts a smaller size of the image forming medium size and the transfer medium size based on the detection results of the first and second detecting means, and the first size is extracted according to the extracted size. The carry amount of the image forming medium by the first carrying unit and the carry amount of the transfer medium by the second carrying unit are set. As a result, even if the sizes of the image forming medium and the transfer medium do not match, the image forming operation according to the smaller size is executed, and a good image is always obtained on the image forming medium. You can

[0018]

EXAMPLES Examples of the present invention will be described in detail below.

FIG. 1 shows a copying machine 1 which is an example of an image forming apparatus.

The copying machine 1 is of a thermal transfer type capable of selectively producing multicolor color copies.

That is, an operation panel (not shown) is provided on the front portion of the upper surface of the main body 1a of the copying machine 1. The upper portion of the main body 1a is an image reading unit 3 for scanning and reading the original O set on the original table 2, and the lower portion is an image forming unit 4. Reference numeral 5 denotes a document cover provided on the document table 2 so as to be openable and closable. The original table 2 is the main body 1
It is fixed to a.

The image reading means 3 includes a first carriage 7 provided with an illumination lamp 6 as a light source, and mirrors 8a and 8a.
The second carriage 8 for bending the optical path by b, the lens 9,
The reflected light from the original O is guided to the photoelectric converter 11 described later,
It is composed of a mirror unit 10 for correcting the optical path length at the time of zooming, a photoelectric converter (conversion unit) 11 for receiving the reflected light from the original O, and a drive system (not shown) for changing the positions of these units.

The first carriage 7 has an illumination lamp 6 for irradiating the original O with light, a reflector 12 as a reflecting mirror that collects the light from the illumination lamp 6 on the original surface, and a reflected light from the original O. Mirror 1 that guides to the carriage 8 side of 2
3 is installed.

The second carriage 8 is equipped with mirrors 8a and 8b for guiding the light guided by the mirror 13 to the lens 9.

The first and second carriages 7 and 8 are connected to each other by a timing belt (not shown) so that the second carriage 8 moves in the same direction at a speed half that of the first carriage 7. Is becoming This allows the lens 9
The scanning can be performed so that the optical path length up to is constant.

The lens 9 has a fixed focal length and can be moved in the optical axis direction during zooming. Further, a lens having a variable focal length such as a zoom lens may be used.

The mirror unit 10 includes two mirrors 10a,
10b, the positions of the mirrors 10a and 10b are changed in accordance with the change of the optical path length corresponding to the selected magnification, and the light from the lens 9 is reflected by the two mirrors 10a and 10b. By bending the optical path, the light is guided to the photoelectric converter 11.

The photoelectric converter 11 photoelectrically converts the reflected light from the original O to convert the image of the original O into C (cyan), G (green), Y (yellow) or R (red), G (. It separately outputs color signals of green) and B (blue) light, and is mainly composed of, for example, a CCD line image sensor. In this case, the original O
3 pixels (C,
G, Y or R, G, B). The output of the photoelectric converter 11 is output to an A / D converter 91 described later.

The movements of the first and second carriages 7 and 8, the lens 9 and the mirrors 10a and 10b are performed by a stepping motor (not shown).

The mirrors 10a and 10b and the lens 9
Are moved by different stepping motors (not shown). The lens 9 is
A spiral shaft (not shown) is rotated by a corresponding stepping motor and is moved in the optical axis direction by the movement of the spiral.

The image forming section 4 has the following structure.

That is, at a substantially central portion in the main body 1a,
A platen drum 22 that constitutes a first conveying unit 71 that conveys a sheet P as an image forming medium is provided.

The periphery of the platen drum 22 is made of an elastic material such as rubber and has a function as a platen roller of the thermal head 24. Further, the platen drum 22 is rotationally driven in a clockwise and counterclockwise directions by a platen motor (not shown) that constitutes the first transport means 71.

The platen drum 22 itself is rotationally driven in the counterclockwise direction so that the paper P is wound around the outer periphery thereof so that the paper P is not displaced during the overlay printing. Around the platen drum 22, pressure rollers 25 are provided at predetermined intervals to prevent the paper P from floating above the platen drum 22.

The circumference of the platen drum 22 is slightly longer than the length of the maximum paper size in the longitudinal direction.

A thermal head 24 as a recording means is arranged in the lower left portion of the platen drum 22. The thermal head 24 is attached to a radiator integrally formed on the rear end surface of the holder. And
Between the platen drum 22 and the thermal head 24,
An ink ribbon 26 as a transfer medium is arranged so as to be conveyed while being in contact with the platen drum 22 side by the thermal head 24. The transport of the ink ribbon 26 is performed by the second transport means 72 including the cores 30 and 31 and a core motor that rotationally drives the cores 30 and 31.

The ink ribbon 26 includes winding cores 30 and 31.
Although not shown together, it is stored in an ink ribbon container,
It can be replaced for each size such as A4 size and B5 size. Then, a pin provided on each ink ribbon container and having a different position for each size is detected by a ribbon sensor 54 as a second detection means provided on the main body 1a.

A paper feed roller 41 is provided below the main body 1a so as to take out the papers P stored in the paper feed cassette 20 one by one.

The paper feed cassette 20 is 1 in FIG.
Although only one piece is shown, a plurality of paper feed cassettes 20 respectively accommodating a plurality of types of paper P (A4, B5, etc.) having different sizes are arranged.

The paper P taken out by the paper feed roller 41
Are transported by the transport roller 42 toward the platen drum 22 diagonally above and to the left of the transport roller 42.

In the vicinity of the transport roller 42, there is provided a paper sensor 53 as a first detecting means composed of an issuing element 51 for detecting the size of the paper P and a light receiving element 52.

The sheet P conveyed toward the platen drum 22 is wound around the platen drum 22 by the gripper 23 and the pressure roller 25 attached along the axial direction of the platen drum 22, and is held. , So that it will be sent accurately.

The paper feed cassette 20 is composed of the main body 1a.
It is removable from the side. Incidentally, 4 in FIG.
Reference numeral 6 denotes a manual paper feeding unit for manually feeding the paper P and the like. The paper P supplied from the manual paper feed unit 46 is also wound around the platen drum 22 in the same manner as above.

The paper P, the front end of which is fixed by the gripper 23, is wound around the platen drum 22 by the counterclockwise rotation, and after the front end passes through the printing area of the thermal head 24, the thermal head 24 is moved by the platen drum 2.
Printing is performed by pressurizing to 2.

When the printing of the first color is completed, the platen drum 22 rotates almost once. here,
The thermal head 24 is once released, and the ink ribbon 26
Is wound up and the next color is cued. Then, the platen drum 22 starts rotating in the clockwise direction, printing is performed by the thermal head 24, and the next color is overprinted (printed).

When the sheet P is discharged, the platen drum 22 is rotated counterclockwise until the trailing edge of the sheet P reaches the sheet discharge guide 27.
2 is rotated clockwise, and the paper P is
The trailing edge is separated from the platen drum 22 and the paper ejection guide 2
Lead to 7. Finally, the front end of the paper P is gripper 23.
The paper P that has been released from the above and has been copied by the paper discharge guide 27 is discharged onto the paper discharge tray 28.

Next, the control system of the copying machine 1 will be described with reference to FIG.

The copying machine 1 has a control means 100 consisting of a main control section 81, a first sub control section 82 and a second sub control section 83.

The main controller 81 includes an operation panel 80, a memory 99, a correction circuit 84, a luminance / color difference separation circuit 85, an image quality improvement circuit 86, a color signal conversion circuit 87, a binarization circuit 88, and a first circuit.
It is connected to the sub control unit 82 and the second sub control unit 83, respectively, and controls these components.

The first sub-control unit 82 is the light source control unit 8
9, the motor drive unit 90, the photoelectric converter 11, the A / D converter 91, and the resolution conversion unit 92, which are connected to each other and control these. The light source control unit 89 is connected to the illumination lamp 6 and controls the lighting and the light amount of the illumination lamp 6. That is, the illumination lamp 6 is turned on during a normal image reading operation.

The motor drive unit 90 drives the scanning motor 18.

The second sub control unit 83 controls the thermal head temperature control unit 93 and the thermal head 24, fetches the detection results of the paper sensor 53 and the ribbon sensor 54, and determines the size of the paper P and the size of the ink ribbon 26. It is designed to be compared with the big and small.

Then, the second sub-control unit 83, based on the above-mentioned comparison result, the first and second conveying means 71, 72.
The transport control is performed.

Next, the operation of the copying machine 1 described above will be described with reference to FIG.
The image forming operation on the sheet P will be mainly described with reference to FIG.

When the paper P is conveyed from the paper cassette 20 toward the platen drum 22, the paper sensor 53
Detects the detection signal corresponding to the size of the paper P by the second sub control unit 83.
To (ST1).

Further, the ribbon sensor 54 sends a detection signal corresponding to the size of the ink ribbon 26 brought into contact with the platen drum 22 to the second sub-control unit 83 (ST2).

The second sub-control unit 83 takes in each detection signal of the paper sensor 53 and the ribbon sensor 54, compares the size of the paper P with the size of the ink ribbon 26 (ST3),
When the size of the paper P is larger than the size of the ink ribbon 26, the first transporting means 71 and the second transporting means 72 are controlled, and the paper P and the second transporting means 72 are controlled by an amount corresponding to the size of the ink ribbon 26. The ink ribbon 26 is conveyed (ST4). In addition, when the size of the paper P is smaller than the size of the ink ribbon 26, the second sub-control unit 83 controls the first carrying unit 71 and the second carrying unit 72 to make the size of the paper P. The paper P and the ink ribbon 26 are conveyed by an amount corresponding to (ST5). As a result,
Even when the size of the paper P and the size of the ink ribbon 26 do not match, the image forming operation matching the smaller size is executed, and a good image can always be obtained on the paper P. it can.

The present invention is not limited to the above-mentioned embodiments, but various modifications can be made within the scope of the invention.

[0059]

According to the present invention described in detail above, by virtue of the above-mentioned configuration, even when the sizes of the image forming medium and the transfer medium do not match, that is, forgetting to replace the paper or transferring the transfer medium. It is possible to provide an image forming apparatus capable of always forming a good image on an image forming medium even if the user forgets to replace the container.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a copying machine that is an embodiment of the present invention.

FIG. 2 is a perspective view showing an arrangement of paper, an ink ribbon, a thermal head, and a platen drum in a copying machine that is an embodiment of the present invention.

FIG. 3 is a block diagram showing a control system of a copying machine that is an embodiment of the present invention.

FIG. 4 is a flowchart showing an image forming operation of the copying machine according to the embodiment of the present invention.

[Explanation of symbols]

 1 Copier 22 Platen Drum 24 Thermal Head 53 Paper Sensor 54 Ribbon Sensor 71 First Conveying Means 72 Second Conveying Means 100 Control Means P Paper

Claims (1)

Claim: What is claimed is: 1. A first transporting means for transporting a plurality of types of image forming media having different sizes, a second transporting means for transporting a plurality of types of transfer members having different sizes, and the first transporting means. Recording means for bringing the transfer member conveyed by the second conveying means into contact with the image forming medium conveyed by the first conveying means to transfer the transfer medium of the transfer member onto the image forming medium to form an image. In an image forming apparatus including: a first detecting unit that detects the size of the image forming medium conveyed by the first conveying unit; and a size of the transfer medium that is conveyed by the second conveying unit. Based on the detection results of the second detection unit and the first and second detection units, a smaller size of the image forming medium size and the transfer medium size is extracted, and according to the extracted size. Conveyance amount of the image forming medium according to the serial first transfer means and the second
An image forming apparatus, comprising: a control unit that sets a transfer amount of the transfer medium by the transfer unit.