JPH1010819A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device which is capable of forming a black-and-white image normally and a color image as necessary, compact and advantageous to manufacturing costs, with a simple constitution. SOLUTION: In an electrophotographic printer part 1 for making a black-and- white print an ink jet part 2 is freely attachably/detachably provided on the downstream side in the carrying of a recording paper, so that the cost of equipment can be reduced by the selection of color printing. At this time, the images of an original at least partially including the color image can be formed by the jetting of color ink. The carrying path between a fixing roll 6 and an ink jet head 18 is made longer than the length of the recording paper and the difference in the carrying speed of the original in which the black-and-white and color images coexist, between the electrophotographic printer 1 and the ink jet part 2 is absorbed to smoothly form the images. Further, the ejecting part of the printer part 1 and the ink jet part 2 are arranged parallely, so that the device can be miniaturized and the position in a carrying direction of the ink jet head 18 can be shifted according to the size of the recording paper, by the movements of cases 2a and 2b.

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 such as a copying machine.

[0002]

2. Description of the Related Art An image forming apparatus such as a copying machine for forming a color image is provided with four types of developing devices of C (cyan), M (magenta), Y (yellow) and BK (black). In addition to the increase in size, the apparatus is complicated and the manufacturing cost is increased, and there is a problem in terms of equipment cost in order to install this type of image forming apparatus and perform full-color image formation. Further, since a black image formed by an image forming apparatus that forms a full-color image is formed by superimposing C, M, and Y toners, if a black character with many thin lines is formed by this type of image forming apparatus, The thin line may be formed thick and may be difficult to read.

Most of the originals handled as image forming objects in ordinary offices and the like are mostly black-and-white originals, and in rare cases, there are many cases where image formation of color originals is required to some extent. Also, in image formation for black-and-white originals, there is a relatively large demand that only the stamped portion and the written portion of red writing be image-formed in red.

In response to this demand, Japanese Patent Application Laid-Open No.
In the 9171 gazette, the approval mark, "important", "confidential"
An image forming system has been disclosed which stamps a red character such as a clear black stamp on a black and white image formed from a document without the influence of heat in a fixing unit.

[0005]

SUMMARY OF THE INVENTION The above-mentioned JP-A-4-14-1
According to the image forming system disclosed in Japanese Patent No. 89171,
It is possible to stamp recognition marks, characters such as "important" and "confidential", and writing characters such as red text on a black-and-white formed image with a red stamp. It is not possible to form an image of a mixed color original.

[0006] The present invention has been made in view of the above-described current state of image formation of the type described above, and its object is to form a black-and-white image and, if necessary, to form a color image. It is an object of the present invention to provide an image forming apparatus which is capable of being manufactured, has a simple miniaturized configuration, and is advantageous in terms of manufacturing cost.

[0007]

According to a first aspect of the present invention, there is provided an image forming apparatus, comprising: a recording medium which is fed from a fixing unit of the electrophotographic unit; A color inkjet unit is detachably mounted at a downstream position of the transport.

[0008] Similarly, in order to achieve the above object, according to a second aspect of the present invention, in the first aspect of the present invention, the recording paper transport path from the fixing section to the color ink jet unit is longer than the recording paper length. Is also set to be long.

Similarly, in order to achieve the above object, according to a third aspect of the present invention, in the first aspect of the present invention, the discharge unit of the single-color electrophotographic unit and the color inkjet unit are provided with the fixing unit. The parts are arranged in parallel with each other.

[0010] Similarly, in order to achieve the above object, the invention according to claim 4 is different from the invention according to claim 1 in that the position of the color ink jet recording paper in the conveying path direction is changed.
It is characterized in that a changing means for changing according to the size of the recording paper is provided.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an explanatory view showing the overall configuration of the present embodiment, FIG. 2 is a front view showing the configuration of the ink jet unit in FIG. 1, and FIG. 3 is a perspective view showing the configuration of the ink jet unit in FIG.

In the present embodiment, as shown in FIG. 1, an ink jet unit 2 for forming a color image is provided on an upper surface of a case 1a of an electrophotographic printer unit 1 for forming a monochrome monochrome image. It is detachably mounted with gold, and the electrophotographic printer unit 1 has a photoconductor 3 on which a toner image of a document image is formed, and the toner image formed on the photoconductor 3 is transferred to recording paper. A transfer roll 5, a fixing roll 6 for fixing the recording paper onto which the toner image has been transferred, and a pressure roll 7 are provided. A paper guide 11 for conveying the recording paper is disposed at a stage subsequent to the fixing roll 6, Paper guide 11
A switching guide 12 is disposed at an end of the switch.

A paper discharge roller 8 is provided at a first switching position of the switching guide 12, and a paper discharging roller 10 is provided at a second switching position of the switching guide 12.

Although not shown, the electrophotographic printer unit 1 has an exposure unit for exposing the photoconductor 3 to a light image of a document, and a developing unit for developing a latent image formed on the photoconductor by the exposure unit into a toner image. A unit is provided.

Further, the electrophotographic printer unit 1 is provided with a CPU 15 for controlling the entire operation.
5, a drive unit of the switching guide 12, a drive unit of the fixing roll 6, a drive unit of the photoconductor 3, a drive unit of the fixing roll 5, an exposure unit and a developing unit are connected.

On the other hand, in the ink jet unit 2 attached to the upper surface of the case 1a, a transport roller 17 is disposed at a position facing the paper discharge roller 8, and near the end facing the upper surface of the case 1a, C, M are provided. , Y, and BK are provided, and transport rollers 20a and 20b are provided with the inkjet head 18 interposed therebetween.

In this embodiment, when the ink jet unit 2 is mounted on the electrophotographic printer unit 1, the CPU 15 of the electrophotographic printer unit 1 is connected to a control circuit (not shown) of the ink jet unit 2. In this embodiment, the length of the recording paper transport path from the fixing roll 6 to the ink jet 18 is set to be longer than the length of the recording paper.

In the present embodiment, as shown in FIG. 3, in the ink jet unit 2, the case 2b to which the ink jet head 18 and the conveying rollers 20a and 20b are attached, and the conveying roller 17 of the ink jet unit 2 are connected. With respect to the attached case 2a, it is free to move in the recording paper conveyance direction along a slide guide 2c attached to the case 2a, and the case 2b is moved to a predetermined position corresponding to the size of the recording paper. , And a pin is inserted into the stopper hole 20 at this position to be fixed.

In this case 2c, the transport rollers 20a,
20b, the ink jet head 18 moves in the paper width direction of the recording paper, as indicated by an arrow Y in FIG. The inks of the colors Y and BK are sequentially ejected to the corresponding positions, so that a color image of the document is formed on the recording paper.

The operation of this embodiment having such a configuration will be described. When all the images of the original are black and white images, when the original is read by the scanner and it is determined that there is no color image portion in the original, the switching guide 12 is switched by the CPU 15 to the paper guide 13 side. , And the operation of the ink jet unit 2 is stopped by the stop signal from the CPU 15.

In this state, an electrostatic latent image of the original image is formed on the photosensitive member 3 by the exposure unit, and the formed electrostatic latent image is developed with black toner by the developing unit. The transferred toner image is transferred to recording paper by the transfer roll 5, and the recording paper to which the toner image has been transferred is subjected to fixing processing by the fixing roll 6 and the pressure roll 7. Then, the recording paper subjected to the fixing process is transferred to the paper guide 11,
The paper is conveyed along the switching guide 12 and the paper guide 13, and is discharged by the paper discharge rollers 10 to the case 2 a of the ink jet unit 2.
Is discharged to the upper surface of the

When the original is a black and white image, for example, a red
In the case of a document in which color images such as red characters such as "important" and "confidential" and writing characters in red are mixed, it is determined that a color image portion exists in the document when the document is read by the scanner. And a switching command from the CPU 15
The switching guide 12 is switched to the discharge roller 8 side, and C
A color print signal is input from the PU 15 to the inkjet unit.

In this state, first, an electrophotographic printer unit 1 forms an image of a black-and-white image portion of the original, and an exposure unit forms an electrostatic latent image of the black-and-white image portion of the original image on the photoconductor 3 by an exposure unit. The developing unit develops the formed electrostatic latent image with black toner, transfers the obtained toner image to recording paper by the transfer roll 5, and fixes the recording paper onto which the toner image has been transferred. The fixing process is performed by the roll 6 and the pressure roll 7.

The recording paper on which the black-and-white image portion of the document has been fixed is conveyed along the paper guide 11 and the switching guide 12, supplied from the paper discharge roller 8 to the conveyance roller 17,
Based on the color print signal from U15, the transport roller 1
7. On the recording paper conveyed intermittently by the transport rollers 20a and 20b, the ink jet head 18 moving in the paper width direction of the recording paper with respect to the color image portion of the document
M, Y, and BK color inks are sequentially ejected to the corresponding positions to form a color image of a color image portion of a document on recording paper, and are discharged onto the upper surface of the case 1a.

In this case, since the conveyance path of the recording paper from the fixing roll 6 to the ink jet head 18 is set to be longer than the recording paper length, if the original is a black and white image and a color image is mixed. The difference in the transport speed between the electrophotographic printer unit 1 and the ink jet unit 2 for the recording paper is absorbed, and the image forming operation on the recording paper is performed continuously and smoothly.

In this way, a high-quality image can be obtained for a black-and-white image containing a color image portion such as a red acknowledgment mark, red characters such as "important" or "confidential", and writing characters in red. The formation takes place.

When the original is a full-color original,
If the original is determined to be a full-color original when the original is read by the scanner, the switching guide 12 is switched to the discharge roller 8 side by a switching instruction from the CPU 15, and the CPU 15 sends the original to the ink jet unit 2. A color print signal is input, and a stop signal is input to the electrophotographic printer unit 1.

In this case, the black-and-white image forming operation is not performed in the electrophotographic printer unit 1 by the stop signal from the CPU 15, and the recording paper fed from the paper feeding unit is changed to the fixing roll 6 and the pressure roll 7 Is transported along the paper guide 11 and the switching guide 12 as a relay transport roll, is supplied from the discharge roller 8 to the transport roller 17, and is transported by the transport roller 17, the transport rollers 20a, 20a, and 2a based on a color print signal from the CPU 15.
0b, the recording paper conveyed intermittently from the inkjet head 18 moving in the paper width direction of the recording paper.
Inks of the colors C, M, Y, and BK are sequentially ejected to the corresponding positions to form a color image of a document on a recording sheet, and the sheet is discharged onto the upper surface of the case 1a.

Further, in this embodiment, when forming an image of a black-and-white image original, an original in which a black-and-white image and a color image are mixed, or a full-color original, the case 2b is made to correspond to the size of the recording paper. Is moved in the direction of conveyance of the recording paper, and the case 2b is fixed to the stopper hole 20 at a predetermined position by a pin, so that the conveyance of the recording paper of each size can be performed by one conveyance roller 17 in the case 2a of the ink jet unit 2. Done.

As described above, according to the present embodiment, a color image can be formed at a low installation cost by selectively attaching the ink jet unit 2 to the electrophotographic printer unit 1 for performing black and white printing. For a black-and-white image document, a document in which a black-and-white image and a color image are mixed, or a full-color document, the selection use or combination use of the electrophotographic printer unit 1 and the inkjet unit 2 is automatically performed.
High-quality image formation can be continuously and smoothly performed on any type of original.

According to the present embodiment, since a color image is formed by ink jet, C, M, Y,
Since the four types of developing units of BK are not required, and the ink jet unit 2 is mounted in a small occupied space, the overall size is significantly reduced, and the black and white image is formed by black toner instead of superimposition of C, M and Y toners. Because it is formed with, black characters with many thin lines are formed thick and not difficult to read,
For both black-and-white originals, originals containing both black-and-white and color images, or full-color originals,
High quality image formation can be performed efficiently.

In this embodiment, by setting the conveyance path of the recording paper from the fixing roll 6 to the color ink-jet head 18 to be longer than the recording paper length, the electronic paper of a document in which a black-and-white image and a color image are mixed can be used. Photo printer unit 1
And absorb the difference in transport speed in the ink jet unit 2,
Although the case where image formation is performed smoothly continuously has been described,
The present invention is not limited to this embodiment,
By driving the paper feed roller 8 intermittently in response to a command from the PU 15, image formation can be performed continuously and smoothly.

In this embodiment, the case has been described in which the case 2b, which has been moved to a predetermined position along the slide guide 2c, is fixed to the stopper hole 20 with a pin in accordance with the recording paper size. The present invention is not limited to this embodiment, and it is possible to form a recess at a predetermined position of the slide guide 2c so that the leaf spring attached to the case 2b engages with the recess. It is.

[0034]

According to the first aspect of the present invention, the color ink jet unit is detachably attached to the monochrome electrophotographic unit at a position downstream of the conveyance of the recording paper sent from the fixing unit of the monochrome electrophotographic unit. , The option of color printing can be selected, which is advantageous in terms of equipment cost, and the high-quality color image formation of a document including a color image at least partially can be easily and simply performed by means of color inkjet. It can be performed efficiently.

According to the second aspect of the present invention, in addition to the effect obtained by the first aspect, the conveying path of the recording paper from the fixing unit to the color ink jet unit is set longer than the recording paper length. Absorbs the difference in transport speed between the electrophotographic unit and the color inkjet unit for originals in which black-and-white images and color images are mixed,
Image formation can be performed continuously and smoothly.

According to the third aspect of the present invention, in addition to the effects obtained by the first aspect of the present invention, the discharge section of the monochromatic electrophotographic unit and the color ink jet unit
Since the fixing devices are arranged in parallel with each other, it is possible to greatly reduce the size of the entire apparatus.

According to the fourth aspect of the present invention, in addition to the effect obtained by the first aspect of the present invention, the position of the recording sheet of the color ink jet in the conveying path direction is changed by the changing means so as to correspond to the size of the recording sheet. Therefore, the recording paper of various sizes can be transported by one type of transport roller, and the manufacturing cost of the apparatus is further reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an overall configuration of an embodiment of the present invention.

FIG. 2 is an explanatory front view showing a configuration of an ink jet part in FIG. 1;

FIG. 3 is a perspective view illustrating a configuration of an ink jet unit in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrophotographic printer part 1a case 2 Ink jet part 2a, 2b case 2c Slide guide 3 Photoconductor 5 Transfer roll 6 Fixing roll 11 Paper guide 13 Paper guide 12 Switching guide 17 Transport rollers 20a, 20b Transport rollers 18 Ink jet head

Claims (4)

[Claims] 1. A color ink jet unit is detachably attached to a single color electrophotographic unit at a position downstream of conveyance of a recording sheet sent from a fixing unit of the single color electrophotographic unit. Image forming apparatus. 2. The image forming apparatus according to claim 1, wherein
An image forming apparatus, wherein a conveying path of a recording sheet from the fixing unit to the color inkjet unit is set longer than a recording sheet length. 3. The image forming apparatus according to claim 1, wherein
An image forming apparatus, wherein a discharge unit of the single-color electrophotographic unit and the color inkjet unit are arranged in parallel with each other with respect to the fixing unit. 4. The image forming apparatus according to claim 1,
An image forming apparatus, further comprising a change unit that changes a position of the color inkjet recording paper in a conveying path direction in accordance with a size of the recording paper.