JPS6319970A - Image forming device - Google Patents

Abstract

PURPOSE:To produce a print original plate producing film in an extremely simple way by using an image producing medium for a monochromatic image to produce images on a medium where images are produced in response to one of image producing signals of plural colors. CONSTITUTION:A luminance signal I and color difference signals C1 and C2 received from a picture quality improving circuit 86 are sent to a color signal converting circuit 87. A main control part 81 selects three primary colors Y, M and C as well as a signal of black B in a print mode. These color signals Y, M, C and B to be sent to binarization circuit 88 are selected by combination of selection signals (a) and (b). The color signals are selected automatically and successively in a normal color copy mode. While the corresponding color signal is selected in response to the operation of a color selection key in a single color mode. In such a way, a print original plate producing film is produced in an extremely simple way in a small size and at a low cost.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention relates to an image forming method for forming an image of a color-separated original document, which is required when creating a printing plate for offset printing, for example. Regarding equipment.

(Prior Art) Recently, plate making and printing technology has made great progress with the development of electronics, and electronic plate making has become mainstream today. This electronic plate making photoelectrically converts the shading of the original image,
By performing certain processing on the electrical signal, the intensity of the light is changed, exposing the film (photosensitive material), and developing it to create negative or positive film, which is the basis of the original printing plate. .

However, in such a method, the manufacturing process was very large, and the grinding machine itself was large and therefore very expensive.

(Problems to be Solved by the Invention) As mentioned above, in the conventional method of creating a film for printing original plates, the manufacturing process is very complicated, and the machine itself is large, so it is very expensive. There is a drawback.

Therefore, the present invention aims to eliminate the above-mentioned drawbacks. It is possible to make a film for printing original plate very easily without using the complicated production process as in the past. Moreover, it is compact and inexpensive, and can be put to practical use in everyday life. It is an object of the present invention to provide an image forming apparatus which can be used as a color copying machine, for example, and which can produce a film for producing a printing original plate without wasting time with the same apparatus.

[Structure of the Invention] (Means and Effects for Solving the Problems) The image forming apparatus of the present invention optically scans a document to read it as a plurality of color signals, and converts each obtained color signal into a plurality of color signals. The image forming signal is converted into an image forming signal, and an image is formed on an image forming medium using a single color image forming signal according to one of the image forming signals of a plurality of colors. The medium is made up of multiple colors, and one of the colors is used to form an image on the image forming medium.This makes it very easy to create a film for creating a printing plate, and usually, for example, color It can also be used as a copy machine.

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

FIGS. 1 and 2 show, as an example of an image forming apparatus according to the present invention, a thermal transfer color copying machine that is capable of selectively producing multicolor color copies and producing films for producing printing original plates. In other words, 1 is the main body of the copying machine, and this main body 1
An operation panel 2 is provided at the front of the top surface. The left side of the main body 1 is a document scanning FB8 for scanning and reading a document set on a document table 7, and the right side is an image forming section 9. Note that 10 is a document cover provided on the document table 7 so as to be openable and closable.

The document scanning section 8 is configured as shown in FIGS. 3 and 4, for example. That is, the document table 7 is fixed to the main body 1, and the document O set on the document table 7 is placed below the document table 7 by moving back once in the direction of arrow a in the figure along the lower surface of the document table 7. A scanner 11 is provided to optically scan and read the image. The scanner 11 supports an illumination lamp 12 that illuminates the original w1o, a photoelectric converter 13 that receives reflected light from the original O, an optical system 14 that guides the reflected light from the original 0 to the photoelectric converter 13, and these. Carriage 1
Consisting of 5. The photoelectric converter 13 transforms the image of the original O into cyan, green, yellow (or red, green,
It separates and outputs a color signal of (blue) light, and is mainly composed of, for example, a CCD type line image sensor. As shown in FIG. 4, the carriage 15 is guided by a guide rail 16 and a guide shaft 17 so as to be able to reciprocate in the direction of arrow a. A scanning motor (for example, a pulse motor) 1 that is capable of forward and reverse rotation is mounted on one end of the guide shaft 17.
A drive pulley 19 is driven by a drive pulley 8, and a driven pulley 20 is disposed at the other end thereof, and a timing belt 21 is stretched between these pulleys 19 and 20. One point of the timing belt 21 is fixed to the carriage 15 via a fixing member 22.

This allows the carriage 15 to move linearly by rotating the scanning motor 18 in the forward or reverse direction.

The image forming section 9 is configured as shown in FIG. 5, for example. That is, a platen 30 is disposed approximately at the center of the image ridge forming portion 9, and a thermal head 31 is disposed on the left side facing the platen 3o. The thermal head 31 is attached to a heat generator 33 that is integrally formed on the rear end surface of the holder 32 .

A ribbon cassette 35 containing a thermal transfer ink ribbon 34 as a printing medium is inserted through the holder 32.
1rPA is freely attached, and a thermal transfer ink ribbon 34 is interposed between the thermal head 31 and the platen 30. As shown in FIG. 5, the ribbon cassette 35 has two parallel winding cores 36 and 37 around which both ends of the thermal transfer ink ribbon 34 are wound, and a midway portion of the thermal transfer ink ribbon 34 is wound around the cores 36 and 37. In order to be interposed between the platen 30 and the thermal head 31, it is covered with a case 38 with a part thereof exposed.

When the ribbon cassette 35 is installed, the winding cores 36 and 37 are connected to a drive shaft of a motor (not shown) via a drive force transmission mechanism (not shown), and are rotated as necessary. . Further, the ribbon cassette 35 is
As shown in the figure, an insertion/ejection opening 3 formed on the right side of the main body 1
It can be attached to or removed from the holder 32 via the holder 9. Note that the insertion/removal port 39 is provided with a lid 40 that can be opened and closed.

A paper feed roller 41 is provided diagonally below the right side of the platen 30, and paper (or plastic film) as an image forming medium housed in a paper feed cassette 42 is provided.
P is taken out one by one. Paper feed row 541
The paper P taken out is sent to the registration rollers 43 disposed diagonally above and to the right of the feed roller 41, and after its leading edge is aligned, the paper P is directed toward the platen 30 by the registration rollers 43. The paper feed cassette 42 is placed in a state where it is wrapped around the platen 30 by the rollers 44 and 45, and is thereby accurately fed.
It can be attached and detached from the front.

Note that 46 in FIG. 5 is a manual paper feeding device for manually feeding the paper P by τ.

The thermal head 31 presses the paper P against the platen 30 via the thermal transfer ink ribbon 34, and as shown in FIG. It is designed to be transcribed. The thermal transfer ink ribbon 34 has a width approximately equal to that of the paper P and is yellow, as shown in FIGS. 6 and 7, for example.

Magenta, cyan, and black ink portions 47Y.

47M, 47C, and 47e are sequentially stacked one on top of the other, and after transferring one color at a time, the paper P is returned to the transfer starting position, and the sheets are accurately stacked one after another.

In addition, in the case of color copying, each ink part 47Y, 47M of the thermal transfer ink ribbon 34 is used as described above.

47c and 47e to form an image and create a film for printing original plate, use the thermal transfer ink ribbon 34.
An ink portion of one color, for example, a black ink portion 47e.
Image formation is performed using

During color copying, the paper P is reciprocated by the number of colors by the rotation of the platen 30. At this time, the path of the paper wAP is to the bottom surface of the paper output tray 48 which is provided on the main body 1 at an angle. The 1st. 2nd guide board 49.5
Leads to 0. This is the platen 3o and the 1st platen. The first guide plates 49 and 50 respectively provided between
．． This is done by the second distribution gates 51, 52. That is, first, the paper 1a P taken out from the paper feed cassette 42
is transferred through the registration rollers 43 and the first transfer gate 51, and its tip end is wrapped around the platen 30. Next, the platen 30 is rotated in the forward direction by a pulse motor (not shown), etc., so that the paper P is transported at a constant speed, and the thermal heads 31 arranged in a line tod shape are arranged in the axial direction of the platen 30.
The heating element (not shown) generates heat in response to the print signal,
As a result, the ink 47 of the thermal transfer ink ribbon 34 is transferred onto the paper P. Then, the leading edge of the paper P that has passed through the platen 3° is sent by the second distribution gate 52 located at the solid line position onto the first guide plate 49 provided on the lower surface of the paper output tray 48. . In this way, when the transfer of ink 47 of one color is completed, the platen 30 is rotated in the opposite direction, so that the paper P is reversely transported and returned to the transfer starting position. At this time, the trailing edge of the paper P is moved to the first
It is sent onto a second guide plate 50 provided along the lower surface of the guide plate 49. In this way, a plurality of colors are transferred by moving the paper P back and forth a plurality of times. and R
Later, when the transfer of all colors of ink 47 has been completed, the second ftaP is rotated to the position shown by the two-dot chain line.
The paper is guided to a paper discharge roller 53 by a sorting gate 52, and is discharged onto a paper discharge tray 48 by this paper discharge row 553.

Note that the black ink portion 4 of the thermal transfer ink ribbon 34
When forming an image using only 7B, that is, when creating a film for creating a printing plate, transfer is performed only once,
The paper P is not moved back and forth, and the paper P on which the transfer has been completed is discharged onto the paper discharge tray 48 as it is.

FIG. 8 shows the operation panel 2, in which the mode key 6 is used to select between normal mode (color copy mode) and monochrome mode.
1. Color selection key 62 for specifying the color in single color mode, numeric keypad 63 for setting the number of copies, etc., clear key 64 for clearing the set number of copies, etc., copy key 65 for starting the copying operation, numbers for displaying the number of copies, etc. A display 66, a status display section 67 for displaying operating status, etc. are provided. The color selection keys 62 include, for example, a Y key 68 for specifying yellow (Y), and an M key 69 for specifying magenta (M).
, C key 70 to specify cyan (C), black (B)
It is composed of a B key 71 for specifying.

FIG. 9 schematically shows the overall control system, which includes a main control section 81, a first sub-control section 82, and a second sub-control section 83. The main 11JIII section 81 includes the operation panel 2, 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, a first sub-control section 82, and a second sub-control section. 83 and are in charge of these controls. The first sub-control unit 82 includes a light source control unit 89, a motor drive unit 9o, the photoelectric converter 13, the A/
It is connected to the D converter 91 and the resolution converter 92, respectively, and controls these functions. The light 1 ill 1111 section 89 is connected to the illumination lamp 12 and performs advance control thereof. The motor drive section 90 is connected to the scanning motor 18.
It is connected to and drives it. The second sub-control unit 83
Thermal head temperature control section 93, the thermal head 3
1. It is connected to various detection switches 94 and drive unit 95, and controls these i+11110. Drive section 95
is connected to a drive system 96 such as a motor and a solenoid to drive the drive system.

The signal flow in FIG. 9 in such a configuration will be explained. The reflected light of the light irradiated onto the original from the illumination lamp 12 forms an image on the photoelectric converter 13 . Photoelectric converter 13
This light is cyan (C).

The signal is separated into green (G) and yellow (Y) analog color signals and sent to the A/D converter 91. The A/D converter 91 converts each analog color signal into a digital signal and sends it to the resolution converter 92. The resolution conversion unit 92
Resolution conversion is performed to match the resolution of the photoelectric converter 13 and the resolution of the thermal head 31, and the result is sent to the correction circuit 84. The correction circuit 84 includes a resolution converter 92
A correction process is performed on each of the C, G, and Y color signals sent from the photoelectric converter 13 to correct for variations in the photoelectric converter 13.
The result is sent to the luminance/color difference separation circuit 85. The luminance color difference separation circuit 85 receives the C, G, and Y signals sent from the correction circuit 84.
Various operations are performed on each color signal of the luminance signal (I
), color difference signal 1 (CI), and color difference signal 2 (C2>) and send them to the image quality improvement circuit 86. Image quality improvement circuit 8
6 analyzes the luminance rX signal, color difference signal 1, and color difference signal 2 sent from the luminance color difference separation circuit 85, performs image improvement processes such as edge emphasis and character identification, and sends them to the color signal conversion circuit 87. The color signal conversion circuit 87 performs color conversion based on the luminance signal, color difference signal 1, and color difference signal 2, which have been subjected to image quality improvement processing, to produce yellow (Y).

It is converted into a color signal of any one of magenta (M), cyan (C), and black (B) [three primary colors (Y, M, C) plus B during printing] and sent to the 2fa conversion circuit 88. The binarization circuit 88 converts the color signal (
Tone conversion, that is, binarization is performed on any one of Y, M, C, and B), and the binarized signal is sent to the thermal head temperature control section 93. Thermal head temperature
The Il[1 section 93 sends a print signal to the thermal head 31 based on the binary signal sent from the 211I conversion circuit 88. The thermal head 31 performs printing (that is, image formation) according to this printing signal.

Here, the color signal conversion circuit 87 will be explained in more detail with reference to Section 10. Luminance signal (I), color difference signal 1 (C1), and color difference signal 2 sent from the image quality improvement circuit 86
Each signal (C2) is sent to a color signal conversion circuit 87, where Y, M.

A binarization circuit 88 converts one of the color signals of C and B.
I am sending them to Y, M, and C.

The selection of the B color signal is performed by the main control section 81.

That is, the main control section 81 supplies the selection signals a and b to the color signal conversion circuit 87, and as shown in the table below, the combination of the selection signals a and b causes the Y signal to be sent to the binarization circuit 88.
, M, C, and B color signals are selected. Note that the above color signals are automatically selected sequentially in the normal color copying mode (for example, in the order of Y-+M-+C-+8), and in the monochrome mode according to the operation of the color selection key 62. The corresponding color signal is selected.

Next, the operation will be explained with reference to the flowchart shown in FIG. First, in step S1, it is determined whether or not the monochrome mode is selected. If the monochrome mode is not selected, it is the normal color copying mode, and the process proceeds to step S2. In step S2, it is determined whether or not the copy key 65 is turned on, and if it is not turned on, step S2 is performed.
1, and if it is turned on, the process advances to step S3. In step S3, an image forming operation is performed. That is, in this case, since the mode is color copying, color copying (image formation) using the gold color of the thermal transfer ink ribbon 34 is performed by the above-described operation. The detailed operation of color copying is as follows.
For example, please refer to Japanese Patent Application No. 60-38051.

In step S1, if the single color mode is selected, this is the mode for producing a film for printing original plate production, and the process proceeds to step S4. In step S4, as an initial setting, the color signal conversion circuit 87 is commanded to convert the yellow (Y) color signal into a color signal, and the process proceeds to step S5. In step S5, it is determined whether the color selection key 62 has been turned on, and if it has not been turned on, the process proceeds to step S6. In step S6, it is determined whether or not the copy key 65 is turned on. If it is not turned on, the process returns to step S5, and if it is turned on, the process goes to step S3. In step S3, an image forming operation is performed. That is, in this case, since it is the production mode for a film for printing original plate production, monochrome copying (image formation) using the black of the thermal transfer ink ribbon 34 is performed by the above-described operation. In this case, the color signal conversion circuit 87
) to a color signal, image formation is performed for the yellow component of the original image.

In this case, it is assumed that, as the paper P, for example, a plastic film is set in advance. As a result, a film for producing a printing original plate for the yellow component of the original image is obtained.

If the color selection key 62 is turned on in step S5, the process proceeds to step S7. In step S7, it is determined whether or not the Y key 68 has been turned on, and if the Y key 68 has been turned on, the process advances to step S8. Step S8
Then, the color signal conversion circuit 87 is commanded to convert the yellow (Y) color signal into a color signal, and the process returns to step S5. Here, if the copy key 65 is turned on, the process advances to step S3 and an image forming operation is performed. In this case, since the color signal conversion circuit 87 is commanded to convert the yellow (Y) color signal into a color signal, uniform formation is performed for the yellow component of the image of the document. As a result, a film for producing a printing original plate for two components of the original image is obtained.

In step S7, if the Y key 68 is not turned on, the process advances to step S9. In step S9, it is determined whether or not the M key 69 has been turned on. If the M key 69 has been turned on, the process advances to step S10. Step 81
If 0, the color signal conversion circuit 87 is commanded to convert hemagenta (M) into a color signal, and the process returns to step S5. Here, if the copy key 65 is turned on, the process advances to step S3 and an image forming operation is performed. In this case, since the color signal conversion circuit 87 is commanded to convert hemagenta (M) into a color signal, image formation is performed for the magenta component of the image on the document.

As a result, a film for producing a printing original plate for the magenta component of the image quality of the Wt manuscript is obtained.

In step S9, if the M key 69 is not turned on, the process advances to step 811. In step S11, C
It is determined whether the key 70 has been turned on, and if the C key 70 has been turned on, the process advances to step S12. In step S12, the color signal conversion circuit 87 is commanded to convert into a Hessian (C) color signal, and the process returns to step S5. Here, if the copy key 65 is turned on, the process advances to step S3 and an image forming operation is performed. In this case, since the color signal conversion circuit 87 is commanded to convert to a Hessian (C) color signal, image formation is performed for the cyan component of the original image. As a result, a film for producing a printing original plate for the cyan component of the original image is obtained.

In step 811, if the C key 70 is not turned on, the process advances to step S13. In step S13,
It is determined that the B key 71 is turned on, and the color signal conversion circuit 87 is commanded to convert the black (B) color signal, and the process returns to step S5. Here, if the copy key 65 is turned on, the process advances to step S3 and an image forming operation is performed. In this case, since the color signal conversion circuit 87 is commanded to convert to a black (B) color signal, image formation is performed for the black component of the image on the document. As a result, a film for producing a printing original plate for the black component of an image of a document is obtained.

In this way, the original is optically scanned to produce cyan.

These three color signals are read as green, yellow, and magenta.

It is converted into image forming signals of four colors cyan and black, and according to one of these four color image forming signals, one color (for example, black) of a plurality of thermal transfer ink ribbons is used to print a plastic film or This is to form an image on paper. This eliminates the need for complex production processes such as conventional exposure and development.
Although it has a relatively simple structure, the film for creating printing plates is very P! 11, and can be realized compactly and at low cost. In addition, it can also be used as a color copying machine, and the same device can be used to create a film for creating a stamp 9 original without wasting time.

[51 Effects of Brightness] As detailed above, according to the present invention, a film for producing a printing plate can be produced in a very FJII manner without using the conventional complicated production process, and it can be realized in a small size and at a low cost. In addition, the step can be used as a color copying machine, for example, and an image forming apparatus can be provided that can produce a film for printing original plate production using the same device without wasting time.

[Brief explanation of the drawing]

The drawings are for explaining one embodiment of the present invention, and FIG. 1 is a schematic perspective view showing the overall configuration with a portion cut away, and FIG.
FIG. 3 is a side view schematically showing the structure of the document scanning section; the fourth figure is a perspective view showing the scanner movement structure of the document scanning section; FIG. 5 is a longitudinal side view schematically showing the configuration of the image forming section, FIG. 6 is a perspective view for explaining the transfer operation state, FIG. 7 is a plan view showing the configuration of the thermal transfer ink ribbon, and FIG. 8 is a plan view of the operation panel, FIG. 9 is a block diagram schematically showing the overall control system, FIG. 10 is a block diagram explaining the color signal conversion circuit in detail, and FIG. 11 explains the operation. This is a flowchart for 0... Original ffl, P... ff1 (image forming medium), 8... Original scanning unit, 9...
...Image forming section, 11...Scanner, 31...
... Thermal head, 34 ... Thermal transfer ink ribbon (image forming medium), 62 ... Color selection key, 81 ... Main control unit, 82.83 ... ...
・Sub-control unit, 87... Color signal conversion circuit, 93.
...Thermal head temperature control section. Applicant's Representative Patent Attorney Takehiko Suzue Figure 3 Figure 4 Figure 5 Leap Figure 7 Figure 9

Claims (7)

[Claims] (1) A reading means for optically scanning a document and reading it as a plurality of types of color signals; A color conversion means for converting each color signal obtained by the reading means into an image forming signal of a plurality of colors; an image forming means for forming an image on an image forming medium using a single color image forming medium according to one image forming signal among the obtained plural color image forming signals; the image forming medium An image forming apparatus comprising a plurality of colors, and forming an image on an image forming medium using one of the colors. (2) The image forming apparatus according to claim 1, wherein the plurality of types of color signals are cyan, green, and yellow, or three types of red, green, and blue. (3) The image forming apparatus according to claim 1, wherein the plurality of color image forming signals are four colors of yellow, magenta, cyan, and black, or three colors of yellow, magenta, and cyan. . (4) The image forming medium is comprised of four colors: yellow, magenta, cyan, and black, of which black is used to form an image on the image forming medium. image forming device. (5) The image forming apparatus according to claim 1 or 4, wherein the image forming medium is a thermal transfer ink ribbon. (6) The image forming apparatus according to claim 1, wherein the image forming medium is paper or a plastic film. (7) The image forming apparatus according to claim 1, wherein the image formed on the image forming medium is used for creating an original plate for offset printing.