JPS6319971A - Image forming device - Google Patents

Abstract

PURPOSE:To simply produce a print original plate producing film by obtaining image forming signals of plural colors from plural types of color signals read out of an original and producing the single-color images or color image in response to the set mode. CONSTITUTION:The reflected light of the light projected on an original from an illumination lamp 12 forms an image on a photoelectric transducer 13. Then the reflected light is separated into plural color signals and sent to a binarization circuit 88 via an A/D converter 91, an image resolution converting part 92, a correction circuit 84, a luminance/color difference separating circuit 85, a picture quality improving circuit 86 and a color signal converting circuit 87. The circuit 88 gives conversion of gradation to the input color signals and drives a thermal head 31. The conversion of gradation is applied to a color designated by a control panel 2 in a single color mode and to all colors in a color copy mode respectively.

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, with this method, the manufacturing process is very difficult. ! It was complicated, the machine itself was large, and it was therefore very expensive. In addition, conventional machines were dedicated to creating original plates and could not be used for other purposes.

(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. However, it has the disadvantage that it cannot be used for other purposes.

Therefore, the present invention is intended to eliminate the above-mentioned drawbacks. It is possible to create a film for printing original plate very easily without using the complicated production process as in the past, and it can be realized in a small size and at low cost. It is an object of the present invention to provide an image forming apparatus that can be used not only for producing a film for producing an original but also for, for example, color copying.

[Structure of the Invention (Means and Functions for Solving 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. It converts the image forming signal into an image forming signal, and forms a single color image on the image forming medium using a single color image forming medium according to a certain color image forming signal among the plural color image forming signals,
This makes it possible to create a film for printing original plates very easily. In addition, by switching the mode, a plurality of color images are formed on the image forming medium by color overlapping using a plurality of color image forming media according to the plurality of color image forming signals, and this allows for example, color copying to be carried out smoothly. can also be used.

(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 the image forming apparatus according to the present invention, a thermal transfer type color copying machine which is capable of selectively producing multicolor color copies and producing films for producing printing original plates. In other words, 1 is the copy body, and this heather 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 section 8 that scans and reads the document set on the document table 7, and the right side is an image forming section 9.
It becomes. 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 reciprocating along the lower surface thereof in the direction of arrow a in the figure. A scanner 11 is provided for optical scanning and reading. The scanner 11 includes an illumination lamp 12 that illuminates the original 0, a photoelectric converter 13 that receives reflected light from the original O, an optical system 14 that guides the reflected light from the original O to the photoelectric converter 13, and supports these. Carriage 15
Consisted of. The charging converter 13 photoelectrically converts the reflected light from the original O to separate and output the image of the original O as cyan, green, and yellow (or red, green, and blue) light color signals, for example. It is mainly composed of 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 Ena. 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 driving 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 disposed 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, the platen 3C1ii! is located approximately in the center of the image forming section 9. A thermal head 31 is disposed on the left side facing the platen 30. The thermal head 31 is attached to a heat radiator 33 that is integrally formed on the rear end surface of the holder 32. A ribbon cassette 35 houses a thermal transfer ink ribbon 34 as an image forming medium via a holder 32.
is detachably installed, 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.
The middle part of the thermal transfer ink ribbon 34 is placed between the platen 30 and the thermal head 31, so that it is covered with a case 38 with a part exposed. When the ribbon cassette 35 is attached, 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, as shown in FIG. 1, the ribbon cassette 35 can be inserted into and removed from the holder 32 through an insertion/removal port 39 formed on the right side of the main body 1. Note that the insertion/removal port 39 has a lid 4 that can be opened and closed freely.
0 is set.

A paper feed roller 41 is provided diagonally below the right side of the platen 30, and a 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 roller 41
The IF P taken out is sent to a registration roller 543 disposed diagonally above and to the right of the paper feed roller 41, and its leading edge is aligned, and then transferred toward the platen 30 by the registration roller 43. , pressing is done by roller 44.45
by platen 301. : It will be in a wrapped state,
This will send it accurately. Here, the paper feed cassette 42
is removable from the front of the main body 1.

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

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.
It is designed to overlap accurately one after the other. Note that the thermal transfer ink ribbon 34 may not have the black ink portion 47e, and in that case, substantially black can be produced by overlapping three colors of yellow, magenta, and cyan.

In addition, in the case of color copying, each ink part 47y, 47M of the thermal transfer ink ribbon 34 as mentioned above.

Image formation is performed using 47c and 47e. On the other hand, when producing a printing original plate production film, a solid black thermal transfer ink ribbon, for example, is used as the thermal transfer ink ribbon 34 to form an image. In this case, it is not necessary to use a solid black thermal transfer ink ribbon, and the black ink portion 47B of the thermal transfer ink ribbon 34 may be used to perform face-to-face formation.

During color copying, the paper P is reciprocated by the number of colors by the rotation of the platen 30, but the path of the paper P at this time 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 information board 49.50
be led upwards. This is the platen 30 and the first platen. The first guide plates 49 and 50 respectively provided between
．． This is done by a second digging gate 51,52. That is, the paper P taken out from the paper feed cassette 42 is
It is transferred through the registration rollers 43 and the first distribution 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) to transport the paper P at a constant speed, and the heating elements of the thermal head 31 arranged in a line tread along the axial direction of the platen 30 (not shown) generates heat in response to the print signal, and thereby the ink 47 of the thermal transfer ink ribbon 34 is transferred onto the paper P. Then, the paper P that has passed through the platen 30
At this time, the tip of the second imaging gate 5 is located at the solid line position.
2, the paper is sent onto a first guide plate 49 provided along the lower surface of the paper discharge 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 first
By the sorting gate 51, the rear end of the paper P is transferred to the first guide plate 4.
It is sent onto a second guide plate 50 provided along the lower surface of the second guide plate 50. In this way, a plurality of colors are transferred by moving the paper P8 back and forth a plurality of times. Then, on al, fffP is displayed, indicating that the transfer of all colors of ink 47 has been completed.
is guided to the paper discharge roller 53 by the second distribution gate 52 which is rotationally displaced to the two-point vi line position at this time, and is discharged onto the paper discharge tray 48 by the paper discharge row 553.

In addition, when performing image formation using a black thermal transfer ink ribbon, that is, when creating a film for creating a printing original plate, the transfer is performed only once, and the paper P is not moved back and forth, and the MP after the transfer is completed. are discharged onto the paper discharge tray 48 as they are.

Figure 8 shows the operation panel 2, with the mode key (
mode selection switch) 61, 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, number of copies, etc. A numeric display 66 for displaying , 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 a Y key 68 for specifying yellow (Y);
), a C key 70 that specifies cyan (C), and a B key 71 that specifies black (CB).

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 control unit 81 includes the operation panel 2, a correction circuit 84, a luminance/color difference separation circuit 85, an image quality improvement circuit 86,
Color signal conversion circuit 87, binarization circuit 88, first sub-control unit 8
2 and a second sub-control unit 83, respectively, and controls these units. The first sub-control unit 82 includes the optical FAII control unit 8
9, connected to the motor drive unit 90, the photoelectric converter 13, the A/D converter 91, and the resolution conversion unit 92, respectively;
In charge of these controls. The light amount control section 89 is connected to the illumination lamp 12 and controls the light amount thereof. A motor drive unit 90 is connected to the scanning motor 18 and drives it. The 281st control section 83 is connected to a thermal head temperature control section 93, the thermal head 31, various detection switches 94, and a drive section 95, and controls these. The drive unit 95 is connected to a drive system 96 such as a motor and a solenoid, and drives the drive system 96 .

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 calculation processes 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 signal, color difference signal 1, and color difference signal 2 sent from the luminance color difference separation circuit 85, performs image improvement processing such as edge emphasis and character identification, and converts the luminance signal to the color signal conversion circuit 87.
send to 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) [the three primary colors (Y, M, C) during printing plus 8] and sent to the binarization circuit 88. The 21ili conversion circuit 88 performs gradation conversion, that is, binarization, on the color signal (any one of Y, M, C, or B) sent from the color signal conversion circuit 87, and converts the color signal into a binary value. The temperature control signal is sent to the thermal head temperature control section 93. The thermal head temperature control section 93 sends a print signal to the thermal head 31 based on the binarized signal sent from the binarization 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 FIG. 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 the 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 normal color copying mode (for example, in the order of Y-M→C-4B), and in monochrome mode, they are selected 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 the vehicle color mode is selected or not. 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 the copy key 65 is turned on or not. If it is not turned on, the process returns to step $1, 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 the mode is color copying, color copying (image formation) is performed using the thermal transfer ink ribbons 34 of a plurality of colors by the above-described operation. The detailed operation of color copying is described in, for example, Japanese Patent Application No. 60-38051, so please refer to it.

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 the mode is for creating a printing original film, monochrome copying (image formation) using a black thermal transfer ink ribbon is performed by the above-described operation.

In this case, since the color signal conversion circuit 87 is commanded to convert the yellow (Y) color signal into a color signal, image formation is performed for the yellow component of the image on the document. In this case,
A solid black thermal transfer ink ribbon is preset,
It is also 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 advances to step $7. In step S7, it is determined whether or not the Y key 68 has been turned on. 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, image formation is performed for the yellow component of the image on the document. As a result, a film for producing a printing original plate for the yellow component 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 $9, it is determined whether or not the M key 69 has been turned on. If six M keys have been turned on, the process advances to step S10. Step 31
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 original image is obtained.

In step S9, if the M key 69 is not turned on, the process advances to step 811. In step 811, 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 812, 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 311, if the C key 70 is not turned on, the process advances to step 813. In step 813,
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 $3 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.

Reads as green and yellow 3fi type color signals,
These three types of color signals are yellow and magenta.

It converts into four-color image forming signals of cyan and black, and forms an image on plastic film or paper using a solid black thermal transfer ink ribbon according to one of these four-color image forming signals. It is something to do. As a result, it is possible to create a printing plate production film very easily with a relatively simple structure without using conventional complicated production processes such as exposure and development.
Furthermore, it can be realized in a small size and at low cost. Furthermore, by switching modes, images are formed on paper using thermal transfer ink ribbons of a plurality of colors in accordance with the image forming signals of the four colors. As a result, it can be used not only for producing films for printing original plates but also for color copying, which is very convenient.

In the above embodiment, a mode key is provided on the operation panel, and the mode is switched using the mode key. However, the present invention is not limited to this. Mode switching may be performed by inputting a code.

[Effects of the Invention] As detailed above, according to the present invention, a film for producing a printing plate can be produced very easily without using the conventional complicated production process, and it can be realized in a small size and at a low cost. In addition, it is possible to provide an image forming apparatus that can be used not only for producing a printing original film but also, for example, as a color copying machine.

[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.
3 is a side view schematically showing the structure of the document scanning section. FIG. 4 is a perspective view showing the scanner moving mechanism of the document scanning section. 5 is a longitudinal side view schematically showing the structure 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 structure of the thermal transfer ink ribbon, and FIG. 8 is a top view showing the structure of the thermal transfer ink ribbon. 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 for explaining the color signal conversion circuit in detail, and FIG. 11 is for explaining the operation. This is a flowchart. O...Original, P...Paper (image forming medium), 2...Operation panel, 8...Original scanning section, 9... ...Image forming section, 11...
・Scanner, 31...Thermal head, 34...
...Thermal transfer ink ribbon (image forming medium), 61.
...Mode key (mode changeover switch), 62.
...Color selection key, 63...Numeric keypad, 8
1... Main control section, 82.83... Sub control section, 87... Color signal conversion circuit, 93...
...Thermal head temperature control section. Applicant's agent Patent attorney Takehiko Suzue 2WA Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (13)

[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 image forming signals of a plurality of colors; a first mode in which a single-color image forming medium is used to form a single-color image on an image-forming medium according to a certain color image-forming signal among the plurality of color image-forming signals obtained; an image forming means having a second mode for forming a multi-color image by overlapping colors on an image forming medium using a multi-color image forming medium according to a multi-color image forming signal obtained by the converting means; An image forming apparatus comprising: a mode switching means for selectively switching between a first mode and a second mode of a forming means. (2) The image forming apparatus according to claim 1, wherein the mode switching means is a mode switching switch provided on an operation panel. (3) The image forming apparatus according to claim 1, wherein the mode switching means switches the mode by inputting a mode switching code using a numeric keypad provided on an operation panel. (4) The image forming apparatus according to claim 1, wherein in the first mode, images are formed on different image forming media using each image forming signal converted by the color converting means. (5) The first mode is characterized in that images are formed on different image forming media using image forming media of the same color based on the image forming signals converted by the color converting means. The image forming apparatus described in . (6) A patent characterized in that the mode switching means has means for specifying image formation of an image forming signal of a specific color among the image forming signals converted by the color converting means in the first mode. An image forming apparatus according to claim 1. (7) 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. (8) 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. . (9) The image forming apparatus according to claim 1, wherein the single color image forming medium used in the first mode consists of one color, black. (10) The plurality of color image forming media used in the second mode are comprised of four colors, yellow, magenta, cyan, and black, or three colors, yellow, magenta, and cyan. image forming device. (11) Claims 1, 6, and 7 characterized in that the image forming medium is a thermal transfer ink ribbon.
The image forming apparatus according to any one of the items. (12) The image forming apparatus according to claim 1, wherein the image forming medium used in the first mode is paper or plastic film. (13) The image forming apparatus according to claim 1, wherein the image formed on the image forming medium in the first mode is used for creating an original plate for offset printing.