JPS6328172A - Image forming device - Google Patents

Abstract

PURPOSE:To extremely simply form a printing original plate forming film of a desired color by reading an original as plural types of chrominance signals, converting into an image forming signal, selecting one image forming signal and using an image forming medium of a single color to form an image on a medium to be formed the image according to the image forming signal. CONSTITUTION:The original is optically scanned by a scanner 11 to read as the chrominance signals of three types of cyan, green, yellow and the chrominance signals of the three types are converted into the image forming signals of four colors of yellow, Magenta, cyan, black. Then, one of the four converted image forming signals is selected by a color selection key, and a thermal transfer ink ribbon of one black color is used according to the selected image forming signal to form the image on a plastic film. Thereby, the printing original plate forming film of the desired color can be extremely simply formed with a comparatively simple constitution without using complicate processes such as an exposure, a development as the conventional way and a compact and an inexpensive film can be realized.

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 is very complicated, and the heating machine itself is 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 and therefore very expensive. It has the disadvantage of being.

Therefore, the present invention eliminates the above-mentioned drawbacks, and makes it possible to create a printing plate production film of a desired color very easily, without using the complicated manufacturing process of the conventional method, and in addition, it can be realized in a small size and at a low cost. The purpose is to provide an image forming apparatus that can.

[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. converting the image forming signal into an image forming signal, selecting one of the converted multi-color image forming signals, and applying the selected image forming signal to a single color image forming medium on the imaged medium. Image formation is performed in this way, and as a result, a film for producing a printing plate in a desired color can be produced very easily.

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

FIGS. 2 and 3 show, as an example of the 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 section 8 that scans and reads the document set on the document table 7, and the right side is a uniformity 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. 4 and 5, 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 the reflected light from the original 0, an optical system 14 that guides the reflected light from the original NO to the photoelectric converter 13, and supports these. Carriage 15
Consisted of. The photoelectric converter 13 photoelectrically converts the light reflected from the original 0 to separate and output the image of the original 0 as cyan, green, and yellow (or red, green, and blue) light color signals, for example. It is mainly composed of a CCDCD beline image sensor. As shown in FIG. 5, 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. At one end of the guide shaft 17, a scanning motor (for example, a pulse motor) 18 capable of forward and reverse rotation is mounted.
The drive pulley 19 is driven by
9°201! ] A timing belt 21 is wrapped around the belt. 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. 6, for example. That is, a platen 30 is disposed approximately at the center of the image forming section 9, and 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 containing a thermal transfer ink ribbon 34 as an image forming medium is detachably attached via a holder 32, and the thermal transfer ink ribbon 34 is interposed between the thermal head 31 and the platen 30. It has become. As shown in FIG. 6, 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 radar 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 drive force transmission grooves (not shown), and are rotated as necessary. Further, as shown in FIG. 2, the ribbon cassette 35 can be inserted into or 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 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 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. The paper P taken out by the paper feed roller 41 is sent to the registration roller 43 disposed diagonally above and to the right of the paper supply roller 41, and after its leading edge is aligned, the paper P is directed toward the platen 30 by the registration roller 43. The roller 44.
45 to the platen 301. : It is in a wrapped state, which allows it to be fed accurately. Here, the paper feed cassette 42 is detachable from the front of the main body 1.

Note that 46 in FIG. 6 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. As shown in FIGS. 7 and 8, the thermal transfer ink ribbon 34 has a width approximately equal to that of the paper P and is yellow.

Magenta, cyan, and black ink portions 47Y.

47M, 47C, and 47B 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 start position, and the sheets are accurately stacked one after another. Note that the thermal transfer ink ribbon 34 may not have the black ink portion 47a, 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 is used as described above.

Image formation is performed using 47c and 47a. 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 blank ink portion 47B of the thermal transfer ink ribbon 34 may be used to form an image.

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 includes the platen 30 and the first. The first guide plates 49 and 50 are respectively provided between the ends of the second guide plates 49 and 50.
This is done by the second distribution gate 51,52. That is, first, the paper P taken out from the paper feed cassette 42 is transferred through the registration rollers 43 and the first distribution gate 51, and its leading end is wound around the platen 30. Next, the platen 30 is rotated in the forward direction by a pulse motor (not shown) to transport the PAP at a constant speed, and the heat generating 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 passed through the platen 3°
At this time, the tip of the second S 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 one layer of ink 47 is completed, the platen 30 is rotated in the opposite direction, so that the paper P is reversely fed 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 sent onto the second guide plate 50 provided along the lower surface of the first guide plate 49. In this way, the paper P is reciprocated multiple times. By doing this, multiple colors are transferred.Finally, when the transfer of all the colors of ink 47 is completed,
1P is guided to the paper discharge roller 53 by the second photographing gate 52, which is rotated to the position shown by the two-dot chain line, and is discharged onto the paper discharge tray 48 by the paper discharge roller 53.

In addition, when performing image formation using a solid 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 reciprocating movement of the paper v1P is not performed, and the paper P after the transfer is completed. are discharged onto the paper discharge tray 48 as they are.

FIG. 9 shows the operation panel 2, with the mode key (
mode selection switch) 61, color selection key (color selection switch) 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 for starting the copying operation. 65, a numeric display 66 that displays the number of copies, etc., a status display section 67 that displays the operating status, etc., - instructs batch printing (i.e., to successively produce a printing plate production film of each hue at - degrees); A batch printing key 72 and the like are provided.

The color selection keys 62 include, for example, a Y key 68 for specifying yellow (Y), six M keys for specifying magenta (M), a C key 70 for specifying cyan (C), and a B key for specifying black (B). 71.

FIG. 10 schematically shows the overall control system, including a main control section 81, a first sub-control section 82 and a second sub-control section 83.
have. The main control section 81 includes the operation panel 2, the correction circuit 84, the IN degree color difference separation circuit 85, and the image quality improvement circuit 8.
6, color signal conversion circuit 87.2 II conversion circuit 88, first sub-control unit 82 and second sub-control unit 83, respectively connected;
It controls these things. The first sub-control unit 82 includes the light source 11i.
111 [1 section 89, motor drive section 90, photoelectric converter 13, A/D converter 91, and resolution conversion section 92 are respectively connected and control these. The front control unit 8 is connected to the illumination lamp 12 and controls the amount of light thereof. The motor drive unit 9o is connected to the scanning motor 18 and drives it. The second sub-control unit 83 is connected to a thermal head temperature control unit 93, the thermal head 31, various detection switches 94, and a drive unit 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. 10 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 1
3 separates this light into analog color signals of cyan (C), green (G), and yellow (Y), and sends the light to an A/D converter 9.
Send to 1.

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 performs resolution conversion to match the resolution of the photoelectric converter 13 and the resolution of the thermal head 31, and sends the result to the correction circuit 84. The correction circuit 84 performs correction processing on each of the C, G, and Y color signals sent from the resolution converter 92 in order to correct variations in the photoelectric converter 13, and sends the results to the luminance color difference separation circuit 85. . The luminance/color difference separation circuit 85 performs various arithmetic processing on each of the C, G, and Y color signals sent from the correction circuit 84, and outputs a luminance signal (1), color difference signal 1 (CI), and color difference signal 2 (C2). The signal is separated into each signal and sent to the image quality improvement circuit 86. The image quality improvement circuit 86 analyzes the luminance signal, color difference signal 1, and color difference signal 2 sent from the luminance color difference separation circuit 85,
The image is subjected to image improvement processing such as edge enhancement and character identification, and then sent to the color signal conversion circuit 87. The color signal conversion circuit 87 receives a luminance signal, a color difference signal 1, and a color difference signal 2 that have been subjected to image quality improvement processing.
Performs color conversion based on , yellow (Y), magenta (
M), cyan (C).

Converts it into a color signal of any one of black (B) [three primary colors (Y, M, C) plus B during printing], and converts it into a binarization circuit 88
send to The binarization circuit 88 receives the color signals (Y, M, etc.) sent from the color signal conversion circuit 87.

III conversion, that is, binarization, is performed on one of C and B), and the binarized signal is sent to the thermal head temperature control section 93. 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), color difference signal @2 sent from the image quality improvement circuit 86
(C2> signals are respectively 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.
This Y, fvl, c.

The selection of the B color signal is performed by the main control unit 811. : Therefore, it is done. That is, the main control unit 81 supplies the selection signals a and b to the color signal conversion circuit 87, and as shown in the table below, Y, which is sent to the binarization circuit 88 according to the combination of the selection signals @a and b. M, C, and B color signals are selected. Note that the above color signals are automatically selected in sequence (for example, in the order of Y-4M→C→B) when in the normal color copy mode or when the batch print key 72 is turned on in the single color mode.
When the batch print key 72 is not turned on in the single color mode, the corresponding color signal is selected in response to the operation of the color selection key 62.

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, so step S1 is performed.
Proceed to step 2. In step S2, it is determined whether or not the copy key 65 is turned on, and if it is not turned on, step S1
Returns to step S3, 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) 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 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, the -batch print flag is reset, and the process proceeds to step S5. In step $5, the color signal conversion circuit 87 is set to Hey Yellow (Y) as an initial setting.
, and the process proceeds to step S6. In step S6, it is determined whether or not the -bulk print key 72 is turned on. If it is not turned on, the process proceeds to step S7, and if it is turned on, the process proceeds to step S8. In step S8, the -batch print flag is set, and the process proceeds to step S7. In step S7, it is determined whether the color selection key 62 has been turned on, and if it has not been turned on, the process advances to step S9. In step S9, it is determined whether the single color mode has been cleared. If it has been cleared, the process returns to step S1; if it has not been cleared, the process proceeds to step S10. In step S10, it is determined whether the copy key 65 has been turned on, and if it has not been turned on, the process returns to step S6.

If the color selection key 62 is turned on in step S7, the process proceeds to step 811. In step S11,
- Reset the batch print flag and proceed to step 812.

In step 812, 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 S13. In step S13, the color signal conversion circuit 8
7 yellow yellow (Y) is commanded to be converted into a color signal, and the process returns to step S6. In step 812, if the Y key 68 is not turned on, the process advances to step 814. In step 314, it is determined whether or not the M key 69 has been turned on. If the M key 69 has been turned on, step S15
Proceed to. In step S15, the color signal conversion circuit 87 is commanded to convert hemagenta (M) into a color signal, and in step S6
Return to

In step S14, if the M key 69 is not turned on, the process advances to step 316. In step 316,
It is determined whether the C key 7o is turned on, and the C key 70 is turned on.
If it is turned on, the process advances to step S17. In step 817, the color signal conversion circuit 87 is commanded to convert into a Hessian (C) color signal, and the process returns to step S6. In step 816, if the C key 70 is not turned on, the process advances to step 818. In step 818, the B key 7
1 is turned on, and instructs the color signal conversion circuit 87 to convert the black (B) into a color signal, and in step S6
Return to

If the copy key 65 is turned on in step S10, the process advances to step 819. In step $19, it is determined whether the -batch print flag is set, and if it is not set, the process advances to step 820. Step 52
At 0, an image forming operation is performed on one sheet of paper using an image forming signal corresponding to the set color. In other words, in this case, the mode is for creating a film for creating a printing master, so
By the above-described operation, monochrome copying (image formation) is performed using a black thermal transfer ink ribbon. In this case, image formation is performed for the set color components of the original image. For example, if yellow (Y) is set, image formation is performed for the yellow component of both images of the original, and if magenta (M) is set, image formation is performed for the magenta component of the original image. In this case,
A solid black thermal transfer ink ribbon is preset,
It is also assumed that, for example, a plastic film is set in advance as the taP. As a result, a film for producing a printing original plate corresponding to the set color components of the original image is obtained.

In this way, when the -batch printing key 72 is not turned on, a film for producing a printing original plate for the color selected and set by the color selection key 62 is obtained.

If the -blanket print flag is set in step S19, the process advances to step 821. Step 821
Then, 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 S22. Step S2
In step 2, the first image forming operation is performed using the image forming signal corresponding to the set color. In this case, since the color signal conversion circuit 87 is commanded to convert the yellow (Y) color signal, #J@ 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 the yellow component of the image of the original is obtained as the first sheet.

In step 822, when the first image forming operation is completed, the process advances to step S23. In step 823,
The color signal conversion circuit 87 is commanded to convert hemagenta (M) into a color signal, and the process advances to step 824. In step S24, a second image forming operation is performed using an image forming signal corresponding to the set color. In this case, since the color signal conversion circuit 87 is commanded to convert hemagenta (M) to a color signal,
Image formation is performed for the magenta component of the original image. As a result, a second film for producing a printing original plate for the magenta component of the III image of the original is obtained.

In step 824, when the second image forming operation is completed, the process proceeds to step 825. In step S25,
The color signal conversion circuit 87 is commanded to convert Hessian (C) into a color signal, and the process advances to step S26. In step 826,
The third image forming operation is performed using the image forming signal corresponding to the set color. 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 third film for producing a printing original plate for the cyan component of the original image is obtained.

In step 826, when the third image forming operation is completed, the process advances to step 827. In step S27,
The color signal conversion circuit 87 is instructed to convert the black (B) into a color signal, and the process proceeds to step 828. In step 828, the fourth image forming operation is performed using the image forming signal corresponding to the set color. In this case, since the color signal conversion circuit 87 is commanded to convert to a color signal (<8),
Image formation is performed for the black component of the original image. As a result, a film for producing a printing original plate for the black component of the image of the original is obtained as the fourth sheet.

In this manner, when the batch printing key 72 is turned on, printing original plate preparation films for each color can be obtained continuously.

As explained above, by optically scanning the original,
It is read as three types of color signals, green and yellow, and these three types of color signals are read as yellow.

The image forming signal is converted into four color image forming signals of magenta, cyan, and black, one of the four color image forming signals to be converted is selected by the color selection key, and the selected image forming signal is used to create a black color. An image is formed on a plastic film using a single color thermal transfer ink ribbon. As a result, the MW of exposure, development, etc.
Although the present invention has a relatively simple configuration and does not require any extensive manufacturing process, it is possible to very easily produce a film for producing a printing original plate of a desired color, and also to realize it in a small size and at low cost. In addition, by switching with the - batch print key, the image formation signals of the four colors can be used to print the four colors using a solid black thermal transfer ink ribbon. Images are sequentially formed on the same number of plastic films as the ie forming signals. This results in −
It is also possible to continuously create a printing original plate production film for each hue at a time, which saves time compared to the case where printing original plate production films for each hue are created one by one.

Furthermore, if it is only possible to continuously create printing original plates for each hue, it is possible that when printing original plates for each hue are successively created, for example, only one film becomes defective due to an image abnormality, etc. When the original printing plate is stored, in order to obtain that one original printing plate production film, it becomes necessary to create the remaining printing original plate production films that are not needed. However, as described above, since it is possible to create only the printing original film for the desired color, that is, the color selected by the color selection key, such inconvenience and waste can be eliminated.

[Effects of the Invention] As described in detail above, according to the present invention, a film for producing a printing plate of a desired color can be produced very easily without using the conventional complicated production process, and it is also small and compact. An image forming apparatus that can be realized at low cost can be provided.

[Brief explanation of the drawing]

The figures are for explaining one embodiment of the present invention, and FIG. 1 is a flowchart for explaining the operation, and FIG. The figure is an external perspective view schematically showing the overall configuration, FIG. 4 is a side view schematically showing the structure of the document scanning section, and FIG. 5 is a perspective view showing the scanner movement vJ trowel structure of the document scanning section. , FIG. 6 is a cross-sectional side view schematically showing the structure of the image forming section, FIG. 7 is a perspective view for explaining the transfer operation state, and FIG. 8 is a plan view showing the structure of the thermal transfer ink ribbon. FIG. 9 is a plan view of the operation panel, FIG. 10 is a block diagram schematically showing the overall control system, and FIG. 11 is a block diagram for explaining the color signal conversion circuit in detail. O...Original, P...Paper (image forming medium), 2...Operation panel, 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 (color selection switch), 72...
...-Block printing key (selector switch), 81...
・Main control section, 82.83...Sub control section, 87.
...Color signal conversion circuit, 93...Thermal head temperature control section. Applicant's Representative Patent Attorney Takehiko Suzue Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 10 Figure 11

Claims (10)

[Claims] (1) A reading means for optically scanning a document and reading it as multiple types of color signals; A color conversion means for converting each color signal obtained by this reading means into image forming signals of multiple colors; selecting means for selecting one image forming signal from among the image forming signals of a plurality of colors obtained; An image forming apparatus comprising an image forming means for forming an image thereon. (2) The image forming apparatus according to claim 1, wherein the selection means is a color selection switch provided on an operation panel. (3) The image forming means forms the same number of images as the plurality of color image forming signals using a single color image forming medium based on the plurality of color image forming signals obtained by the color converting means. 2. The image forming apparatus according to claim 1, further comprising a mode in which image forming is performed sequentially on an image forming medium. (4) The image forming apparatus according to claim 3, wherein switching to the mode is performed by a changeover switch provided on an operation panel. (5) 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. (6) 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. . (7) The image forming apparatus according to claim 1, wherein the single color image forming medium is made of one color, black. (8) The image forming apparatus according to claim 1 or 6, wherein the image forming medium is a thermal transfer ink ribbon. (9) The image forming apparatus according to claim 1, wherein the image forming medium is paper or a plastic film. (10) 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.