JPH02170775A - Image forming device - Google Patents

Abstract

PURPOSE:To reduce the number of parts and to make the packaging area of an operational panel small by commonly using a color density UP key, a color density DOWN key and a color density display device in a color density setting part for each color. CONSTITUTION:A color density setting part 58 sets respective color densities for yellow (Y), magenta (M), cyan (C) and black (B). It is composed of a selective key 56a to switch which to set the color density of the colors of the Y, M, C and H, a display device 58b to display the selected color, a color density UP key 58c to darken (UP) the color density of the color selected by the selective key 58a, a color density DOWN key 58d to lighten (DOWN) the color density of the color selected by the selective key 58a and a color density display device 58e to indicate the color densities set by the keys 58c and 58d. Thus, the number of parts can be reduced, and the packaging area of the operational panel can be made small.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) This invention, for example, reads an image of a document using a CCD line sensor, and forms a full-color image on the paper according to the read signal. The present invention relates to an image forming apparatus such as a color copying machine.

(Prior Art) In recent years, as a copying machine, a color copying machine that utilizes digital technology and uses a thermal transfer type ink ribbon has been developed and put into practical use.

However, in such color copying machines, the color density of each color is specified using separate switches. Therefore, there are disadvantages in that the number of parts is large and the mounting area of the operation panel is large.

(Problem to be solved by the invention) As mentioned above, this invention eliminates the drawbacks of requiring a large number of parts and a large mounting area for the operation panel. The purpose is to provide an image forming apparatus that can.

[Structure of the Invention] (Means for Solving the Problems) The image forming apparatus of the present invention includes a reading means for optically scanning a document and reading it as a plurality of types of color signals, and a plurality of color signals obtained by the reading means. a color conversion means for converting into a color image forming signal; an image forming means for forming an image on an image forming medium using an image forming medium according to a plurality of color image forming signals obtained by the color conversion means; By changing the image forming signal for each color by the conversion means, the density during image formation can be increased to 511M! A color density adjustment means, an instruction means for instructing the color density adjustment means to adjust the color density, and an instruction means provided integrally with the instruction means,
The above instruction means includes selection means for selecting the color to be specified by igl.

(Operation) This invention optically scans a document and reads it as multiple types of color signals, converts each of the read color signals into a multiple color image (image forming signal) using a color conversion means, An image is formed on an image forming medium using an image forming medium according to image forming signals of a plurality of colors, and the density at the time of image forming is changed by changing the image forming signal for each color by the color conversion means. For those adjusted by color density adjustment means,
An instruction means for instructing adjustment of color density by the color density adjustment means and a selection means for selecting a color for which adjustment is instructed by the instruction means are integrally provided.

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

FIG. 2 shows, as an example of the image forming apparatus of the present invention, a thermal transfer type color copying machine that can selectively produce multicolor copies. In other words, 1 is the copying machine main body,
An operation panel 50 is provided at the front of the upper surface of the main body 1 . The upper part of the main body 1 is a document table (transparent glass) 2.
Original scanning unit 3 that scans and reads the original O set above
, and an image forming section 4 at the bottom. Note that 5 is a document cover provided on the document table 2 so as to be openable and closable.

Further, the document table 2 is fixed to the main body 1.

As shown in FIG. 1, the operation panel 50 includes a copy key 51 for starting a copying operation, a numeric keypad 52 for setting the number of copies, etc., a copy mode setting key 53a for setting a color copy mode, a monochrome copy mode, etc., a copy mode Display device 53b
1..., copy density setting key 54a for setting copy density
, 54b, a copy density display 54c that displays the copy density set by the copy density setting keys 54a and 54b.
1... DOWN key 55a as a copy magnification setting key for setting the copy magnification, 100% key 55b1 UP key 55c1, jam display section 56 that displays the jam position, number of copies, copy magnification, and various messages. A message display section 57, a color density setting section 58, and the like are provided.

The color density setting section 58 sets the color density of each of yellow Y, magenta M1 cyan C1 black B, and switches which color density of yellow Y1 magenta M1 cyan C1 black B is to be set. Selection key 58a1 Display 58b for displaying the color selected by this selection key, . . . Color density U for increasing the color density of the color selected by the selection key 58a.
P key 58c1 decreases the color density of the color selected with the selection key 58a (DOW).
N), a color density DOWN key 58d, and a color density display 58e1, which shows the color density set by these keys 58c, 58d.

The document scanning section 3 is configured as shown in FIGS. 2 to 4, for example. That is, a first carriage 7 in which an illumination lamp 6 is installed as a light source, a second carriage 8 that bends the optical path with a mirror, a zoom lens 9, and guides reflected light from the original O to a photoelectric converter 11, which changes the optical path length when changing magnification. It is comprised of a mirror section 10 that performs correction, a photoelectric converter (conversion means) 11 that receives reflected light from the original O, and a drive system (not shown) that changes the positions of these components.

The first carriage 7 includes an illumination lamp 6 that irradiates light onto the document O, a glue deflector 12 that serves as a reflector that collects the light from the illumination lamp 6 onto the surface of the document, and a second carriage that directs the reflected light from the document O. A mirror 13 that guides the camera to the 8 side is mounted.

The second carriage 8 includes a mirror 8a that guides the light guided by the mirror 13 to the zoom lens 16.

8b is installed. The first and second carriages 7.
8 are connected to each other by a timing belt 18, and the second carriage 8 moves at 1/2 the speed of the first carriage 7 in the same direction. This makes it possible to scan so that the optical path length up to the zoom lens 16 is constant.

The zoom lens 16 has a fixed focal length and is moved in the optical axis direction when changing the magnification.

The mirror part 10 is composed of two mirrors 10a11 and Ob, and the position of these mirrors 10a110b is changed according to the change in the optical path length corresponding to the selected magnification ratio. light above 2
By bending the optical path with two mirrors 10a110b,
The light is guided to a photoelectric converter 11.

The photoelectric converter 11 converts the reflected light from the original O into a cyan image by photoelectrically converting the image of the original O.

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. In this case, one pixel of the original O corresponds to three consecutive elements (C, G, Y) of the CCD sensor. The output of the photoelectric converter 11 is output to an A/D converter 91, which will be described later.

The first and second carriages 7.8, mirrors 10a, 10
The movement of b is performed by a stepping motor 18, respectively.

The first and second carriages 7.8, as shown in FIG. It is designed to be moved according to the movement.

The zoom lens 16 has a spiral shaft (not shown) rotated by a corresponding stepping motor (not shown), and is moved in the optical axis direction by this spiral movement.

The image forming section 4 is configured as shown in FIG. 2, for example. That is, the platen drum 22 is disposed approximately at the center of the image forming section 4 . The platen drum 22 has a periphery made of an elastic material such as rubber, and functions as a platen roller for the thermal head 24. The platen drum 22 rotates clockwise to wrap the paper P around itself, thereby preventing the paper P from shifting during overlapping printing. Pressure rollers 25, . . . are provided around the platen drum 22 at predetermined intervals to prevent the paper P from floating up from the platen drum 22.

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

A thermal head 24 is disposed diagonally below and to the left of the platen drum 22 . The thermal head 24 is attached to a heat radiator integrally formed on the rear end surface of the holder. Then, the platen drum 22 and the thermal head 2
4, there is an ink ribbon 26 as an image forming medium.
There is an intervening state.

The cores 30 and 31 of the ink ribbon 26 are connected to a drive shaft of a motor (not shown) via a drive force transmission mechanism (not shown), and are driven to rotate as required.

A paper feed roller 41 is provided at the lower portion of the main body 1, and is adapted to take out sheets P as a wave direction image forming medium stored in the paper feed cassette 20 one by one.

The paper P taken out by the paper feed roller 41 is transferred to the transport roller 42
The transport roller 42 is sent to the registration roller 21 disposed diagonally above and to the left of the conveyance roller 42, and its tip is aligned.Then, the registration roller 21 transports it via the guide 43 toward the platen drum 22, and the gripper 23. When pressed, the paper is wound around the platen drum 22 by the rollers 25, . . . , and is thereby accurately fed.

Here, the paper feed cassette 20 is detachable from the side of the main body 1. Note that 46 in FIG. 2 is a manual paper feeding device for manually feeding paper P and the like. The paper P fed from the manual paper feeder 46 is also wound around the platen drum 22 in the same manner as described above.

The paper P whose leading edge is fixed by the gripper 23 is wound around the platen drum 22 by clockwise rotation, and after the leading edge passes through the printing area, the paper P is placed in the thermal head 24.
is pressed against the platen drum 22, and printing is performed.

When printing of the first color is completed, the platen drum 22 has rotated approximately once. Here, the thermal head 24 is once released, the ink ribbon 26 is wound up, and the next color is located.

Then, the platen drum 22 starts rotating clockwise again, printing is performed by the thermal head 24, and the next color is overprinted (printed).

In this manner, in the case of full-color copying, image formation is performed by four operations of yellow, magenta, cyan, and black, or three operations of yellow, magenta, and cyan. In the case of a single color such as black, it is performed in one operation.

When discharging the paper, the platen drum 22 is rotated clockwise until the rear end of the paper P reaches the paper discharging guide 27, and after reaching the gap, the platen drum 22 is rotated counterclockwise. A separation claw (not shown) separates the rear end of the paper P from the platen drum 22 and guides it to the paper discharge guide 27. Finally, the leading edge of the paper P is released from the gripper 23, and the paper P, which has been copied and transported by the paper discharge guide 27, is discharged onto the paper discharge tray 28.

FIG. 5 schematically shows the overall control system, which includes a main control section 81, a first control section 82, and a second sub-control section 83. The main control section 81 includes an operation panel 50, 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 connected to each other and control these.

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

The motor drive unit 90 drives the scanning motor 18 . The second sub-control unit 83 includes a thermal head temperature/control unit 93, the thermal head 31, and various detection switches 94.
and the drive section 95, and control these components. 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 correction circuit 84 performs standardization (shading correction, that is, correction of variations in the photoelectric converter 11) on image data (after resolution conversion) obtained by A/D converting the reflected light from the original O.

Further, the color signal conversion circuit 87 will be explained with reference to FIG. The luminance signal (I), color difference signal 1 (C1), and color difference signal 2 (C2) sent from the image quality improvement circuit 86 are sent to the color signal conversion circuit 87, where Y, M, C, Any one of the B color signals is sent to the binarization circuit 88, and the main control section 81 selects the Y, M, C, and B color signals. That is, as shown in the table below, the main control unit 81 receives the signal a.

Y is sent to the binarization circuit 88 by the combination of b.

M, C, and B color signals are selected. Note that the above color signals are automatically selected sequentially (for example, Y→M-C→
B).

Further, when the color signal conversion circuit 87 sends each color signal of Y, M, C, and B to the binarization circuit 88, the main control unit 88
The level of each signal to be sent out is changed depending on the concentration signal supplied from 1. The density signal supplied from the main control section 81 is designated and selected by the color density setting section 58 corresponding to each color.

Next, the operation in the above configuration will be explained. For example, the operator now specifies copy conditions using the operation panel. At this time, if the selection key 58a is not pressed, the copy density of each color is the standard (q4 (preset value)).
When the selection key 58a is pressed, the density change mode is entered.

In this density selection mode, first, yellow Y is selected and designated by the selection key 58a. At this time, the indicator 58b corresponding to yellow Y is lit.

Next, press the color density UP key 58c or color density DOWN.
The color density is set using the key 58d.

Next, the selection key 58a is used to switch and designate magenta M. At this time, the display 558b corresponding to magenta M is lit. Next, the color density is set using the color density UP key 58c or the color density DOWN key 58d.

Also, for cyan C and black B, the selection key 58
a'''C'' is selected, and the color density is set using the color density UP key 58c or the color density DOWN key 58d.

In such a state, when the copy key 51 is turned on, copying is performed according to the copy once setting.

That is, the reflected light of the light irradiated onto the document O from the verification lamp 6 is imaged on the photoelectric converter 11.

The photoelectric converter 11 converts the light into cyan (C) and green (G).
), separated into yellow (Y) analog color signals, and A/
It is sent to the D converter 91. The A/D converter 91 converts each analog color signal into a digital signal, and outputs the digital signal to the resolution converter 92.

The resolution converter 92 converts the resolution of the photoelectric converter 11 and the
Resolution conversion is performed to match the resolution of the multihead 24, and the result is sent to the correction circuit 84. Correction circuit 84
performs correction processing (shading correction) on each of the C, G, and Y color signals sent from the resolution converter 92 to correct variations in the photoelectric converter 11, and sends the results to the luminance color difference separation circuit 85. send. The luminance and color difference separation circuit 85 performs various calculation processes on the C, G, and Y color signals sent from the correction circuit 84, and converts the luminance signal (re, color difference signal 1
(C1) and color difference signal 2 (C2), and send them to the image quality improvement circuit 86. The image quality improvement circuit 86 receives the luminance signal, color difference signal 1, and color difference signal 1 sent from the luminance and color difference separation circuit 85.
The color difference signal 2 is analyzed, subjected to image quality improvement processing such as edge emphasis and character identification, and sent 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 that have been subjected to image quality improvement processing, and converts yellow (
Y), magenta (M), cyan (C), black (B)
It is converted into any one color signal (signal corresponding to 4 degrees) of [the three primary colors (Y, M, C) plus B during printing], and the level corresponding to the density signal supplied from the main control unit 81. The data is changed and sent to the binarization circuit 88. Binarization circuit 88
is the color signal (Y,
M.C.

B) is subjected to area gradation conversion, that is, binarization, using a dither method or the like, and the binarized 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 24 based on the binarized signal supplied from the binarization circuit 88 .

Further, in response to the input of the copy key 51, the paper P in the paper feed cassette 20 is taken out by the paper feed roller 41, and the taken out paper P is transported by the transport roller 42 and the registration roller 21.

Then, the paper P conveyed by the registration rollers 21 is guided to the platen drum 22 via a guide 43, and its leading end is fixed by a gripper 23. Thereby, the paper P is wound around the platen drum 22.

Depending on such conditions, the thermal head 24:
Printing (that is, image formation) is performed on the paper P wound around the platen drum 22 in accordance with the print signal.

When the printing is finished, the main control section 81 turns off the illumination lamp 6, discharges the paper P wound around the platen drum 22, and ends the copying operation.

As mentioned above, the color density UP subkey color density DOWN key in the color density setting section and the color density display are commonly used for each color, so the number of parts can be reduced and the mounting area of the operation panel can be reduced. can.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to provide an image forming apparatus in which the number of parts can be reduced and the mounting area of the operation panel can be reduced.

[Brief explanation of the drawing]

The drawings are for explaining one embodiment of the present invention. Fig. 1 is a plan view showing the configuration of the operation panel, Fig. 2 is a sectional view schematically showing the overall structure, and Fig. 3 is a cross-sectional view schematically showing the overall structure. Fig. 4 is a schematic perspective view showing a part of the configuration, Fig. 5 is a block diagram schematically showing the overall control system, Fig. 6 is a diagram for explaining the main part of Fig. The figure is a block diagram for explaining the color signal conversion circuit in detail. 0...Original, P...Paper (image forming medium), 2...
. . . Original table, 3. Original scanning unit, 4. Image forming unit, 11. Charging converter, 6. Illumination lamp, 22.
...Platen drum, 24...Thermal head, 26
. . . Ink ribbon (image forming medium), 50 . . . Operation panel, 58 . . . Color density setting section, 58a . ...Color density DOWN key 58e...Color density display, 81...Main control section, 87...Color signal conversion circuit. Applicant's agent Patent attorney Takehiko Suzue Figure 5

Claims (1)

[Scope of Claims] 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; An image forming means for forming an image on an image forming medium using an image forming medium according to image forming signals of a plurality of colors obtained by the converting means, and changing an image forming signal for each color by the color converting means. Accordingly, a color density adjustment means for adjusting the density during image formation, an instruction means for instructing adjustment of the color density by the color density adjustment means, and an instruction means provided integrally with the instruction means, the adjustment being performed by the instruction means. An image forming apparatus comprising: a selection means for selecting a specified color.