JPS61193166A - Bicolor copying device - Google Patents

Abstract

PURPOSE:To obtain vivid bicolor copy images with easy operation by controlling a device so that only one of the first and the second developing means different in color is operated in accordance with the designation of the first or the second original area designating means which designates an area of color copy of an original. CONSTITUTION:An original 21 is set faceup on an original pressing plate 20, and a squared sheet 22 is covered on the original 21, and an optional area of the original is designated by a ditigizer buried on the original is designated by a ditigizer buried on the original pressing plate 20. Its coordinates are subjected to A/D conversion and are subjected to the operation processing by a CPU and are stored in a RAM, and flickering of an LED array is controlled by a driving circuit. An electrostatic latent image where the optional area of the original is erased is developed by a read developing device 5, and the image is transferred to a paper 9 by a transfer charger 7 and is fixed by a fixing device 12 and is returned to a position near a paper feeding guide 10. In the next cycle, another area is erased by the LED array 4 when an electrostatic latent image is formed, and the area which is not erased is developed by a black developing device 6 and is transferred to the copy paper developed by a red toner and is fixed, and the copy paper is ejected out of a machine by a switching means 13, thus obtaining a bicolor copy.

Description

[Detailed Description of the Invention] (Scope of Industrial Application) The present invention is capable of copying at least two different colors from the same document into a first part designated as an area and a second part designated as a developed area. The present invention relates to a two-color copying apparatus that can perform two-color copying.

(Prior Art) Conventionally, in order to make a two-color copy from a single original using this type of device, if the original to be copied is already made of two colors, the reflected light from the original is colored. There is a method of separating and forming a latent image, but this method is not only troublesome to form a latent image, but also because it separates the colors, depending on the original, for example, if the text is blackish red, it may appear black. Copied colors or black and red color mixing may occur in some cases.

Furthermore, with this method, it was impossible to extract two-color bees from a single-color original. Another method is to swap two current coins with different colors. According to this method, the manuscript can be monochrome or multicolor, but
Make two types of originals by cutting and pasting them, one for the part you want to change color and the other part, and align them.

Although it is used to make copies, it is troublesome to replace the developing device, cut out and paste the original, align the originals, etc., and it is necessary to make copies twice.

(Problems to be Solved by the Invention) Therefore, the problem to be solved by the present invention is to solve the problem by solving the following problem: To make copies of necessary parts of an original in at least two different colors separately.

(Object of the Invention) An object of the present invention is to provide a new two-color copying apparatus that is improved in view of the various drawbacks of the conventional apparatus.

Another object of the present invention is to provide a two-color copying apparatus that can copy a document in at least two different colors by simply specifying a specific area of the document.

(Example) FIG. 1 is a sectional view showing an example of the present invention. In the figure, a photosensitive drum 1 is uniformly charged by a charger 2 and then forms an electrostatic latent image in response to a light image 3 from an original. Reference numeral 4 denotes an LED array, which is normally used to erase charges in non-image areas, but here it is also used to erase arbitrary areas of the document.

To designate a desired area on a document, the document 21 is placed face up on the document pressure plate 20 as shown in FIG. A grid sheet 22 is placed over the set original 21 to form a trap so that the original position can be accurately determined (Figure 3).
. The original is placed so that it is against the top left. Also, the left end is displayed as a reference. Original pressure plate 20 upper I/
A digitizer is embedded in c, and two points (Xi, Yi) and (Xj) on the diagonal of the area specified.

By pressing Yj), you can specify an area with these two points as diagonals.

The document 21 with the designated area is set on the document glass as shown in Figure 4, but the front and back sides are reverse buttons. Original glass 2
1 as shown in Figure 5.

The top left is the abutment reference, and the left edge of the document is displayed as the reference. Therefore, it is upside down in the Y direction.

By setting the original 21 upside down with the left edge as a reference from above the original pressure plate 20 onto the original glass 23, the value read by the digitizer and the actual position of the original 21 on the original glass 23 is X. Although the directions are exactly the same, the positions are reversed in the Y direction.

The coordinates specified by the digitizer are A/D converted as shown in Figure 6, and input to the CPU and processed and stored in memory (RAM).The signals processed by the CPU are sent to the LED array by the drive circuit. Controls blinking.

The blinking of the LED is controlled by the timing of the position at Xi in the document scanning direction (X direction) K and the time from Xi to Xj, and in the direction perpendicular to the document scanning direction (Y direction)
It is controlled by the number of ED lights. Although the position of the original on the digitizer and the position of the original on the original glass are opposite in the Y direction, this correction is also processed by the CPU.

The electrostatic latent image that has been erased from any area of the document is transferred to a red developing device 5.
Develop the areas not erased by Next, at the position of the black developing device 6, measures are used to prevent black development from occurring, such as separating the black developing device 6 from the photosensitive drum 1, or applying a bias that prevents the black developing device 6 from developing while remaining in contact with the photosensitive drum 1. The image visualized with the red toner is electrostatically transferred by a transfer charger 7 to a paper 9 that is conveyed through a paper feed guide 10, and is further separated from the photosensitive drum 1 by a separation static eliminator 8 and transferred to a conveyance means. 11 and is fixed by a fixing device 12. The fixed image is transferred to the transport path 1 for multiple copying by the switching means 13.
4 and returned to the vicinity of the paper feed guide 10.

The photosensitive drum 1 after transfer separation is cleaned by a cleaning means 1
51/c, the residual toner is removed, and the static elimination lamp 16I is turned on.
/c Therefore, after making the potential on the drum uniform, the next cycle begins. As before, an electrostatic latent image is formed in response to the light g113 from the photosensitive drum 1 document uniformly charged by the charger 2, but this time the area erased in the previous cycle is removed by the LED array 4. An area that is not erased, or conversely, an area that was not erased in the previous cycle (in this case, the area to be erased and the area not to be erased may be completely newly specified).

).

The area specified last time is stored in memory (RAM), and in this cycle it is stored in memory (RA) by the CPU.
M) is called and arithmetic processing is performed, and the LED is set so that the document scanning direction and lighting location are completely opposite to the previous cycle.
The lighting timing and number of lights are controlled.

The area that was not erased this time will be developed by the black developer 6, but it will not be developed at the red developer 5 position, so the red developer 5 should be moved away from the photosensitive drum 1 in the same way as the black developer in the previous cycle. Apply a bias that does not cause development while keeping in contact. The image was developed with black toner, and the copy paper that was previously developed with red toner was moved to the image height position of the drum and registration roller 1.
7, the paper is electrostatically transferred by a transfer charger 7, separated from the photosensitive drum 1 by a separation static eliminator 8, passed through a conveying means 11, fixed by a fixing device 12, and transferred by a switching means. 13, the developer is then discharged to the outside of the machine, and a two-color copy is completed.Next, the operation of the developing device during automatic two-color copying will be explained based on FIG.

Normally, when multicolor development is used, a mechanical method is used, such as removing the developing device from the photosensitive drum with a plunger or eccentric cam when not in use, or cutting the ears of developer on the developing cylinder. .

Further, in jumping development, compared to a two-component magnetic brush, the developer is not in contact with the photosensitive drum, which is advantageous for color mixing, and in some cases, only a development bias is required. Of course, even in this case, it goes without saying that if the non-convenient current device also uses a mechanical color mixing prevention means, it will be more reliable against color mixing.

When area designation, color selection, and color mode are selected using the operation buttons and the copy button is pressed, the machine will automatically switch to 2 from CPUK.
Color copy mode works.

- An explanation will be given of the operation when applying the output of the red developing high voltage transformer to the red developing device when copying a certain color area in red.

When the set value of the density adjustment volume (not shown) is input to CPUK and calculated, a DC bias control signal is input to the red developing high voltage transformer through the D/A converter.

This control signal enters the differential amplifier circuit and is input to the DC-DC inverter to which the output from the variable frequency oscillation circuit is input. The output current amplifies the pulse generated by the pulse oscillation circuit, is superimposed on the AC component boosted by the step-up transformer, and is applied to the red developing device. At this time, both the DC bias SW circuit and the AC bias SW circuit of the red current high voltage transformer are switched in the direction in which high voltages of KDC and AC are generated. The high-voltage transformer for black development has AC output/I'1 off according to the CPU signal, and only the DC high-voltage output is turned on by the DC bias SW circuit, and the voltage is controlled to such a level that the black toner is not developed from the developing device to the drum. .

Next, in the second color black copy stored in the ROMK, the DC and AC components of the high voltage transformer for black development are in the ON state, completely opposite to the case of the red copy, as in the case of the red development mentioned above. Similarly controlled, conversely, the AC high voltage component I/1off% of the high voltage transformer for the red developer is controlled to a voltage that does not cause the red toner to be developed from the developing device to the drum.

The above uses two high-voltage transformers for red and black development,
If the developing characteristics of red and black are similar, a high voltage transformer for one color can be shared by combining the developing devices with separate and close developing devices. Alternatively, only the AC high voltage may be common, and a DC high voltage transformer may be provided separately.

In this embodiment, the method of specifying the area is by using a digitizer, but the method is not limited to this, and a method of manually reading and keying the coordinates of the document may also be used.

Referring to FIG. 8, an explanation will be given of an operation method for automatic two-color copying with area specification performed manually.

First, the user presses the area designation button 30 to designate either the inside 31 or the outside 32 of the designated area. 33 and 34 are LEDs indicating that this mode has been selected by the button. Next, press the color selection button 40 to select the color of the specified area. For example, if you want to make a color copy of the inside of the designated area, select 31 with the area designation button 30 and select 41 with the color selection button 40. Next, to specify the coordinates of the designated area, two points on the diagonal of the rectangular area are input using the keyboard 70. To input, press input key 71 and then press s (XI, Yl)
, enter the coordinates of (X2.Yt). Pressing the input key 71 at the end of inputting or separating each coordinate is distinguished from the display of the number of sheets by K. For example, X1=10. Y1=5.
X2=20. If Y2=15, enter the information as follows:

Next, only the area specified by the color mode button 60 is copied in the selected single color (61), or the specified area is copied in the selected single color.

Select whether to perform automatic two-color copying (62)K in which other areas are copied in another unselected color (for example, black).

As described above, the copy button 80 can be pressed after selecting the area specification one color selection and the coordinate specification one color mode.

Alternatively, the color mode selection button 60 may not be provided and each display panel 61, 62 may be used as a copy button for temporary color copying.

In this example, only one rectangle is specified as an area, but two or more areas or an area with a complicated shape can be specified using a digitizer or CPU.
, is possible if there is sufficient memory capacity.

Also, here the developing device is black and a color (for example, red), but
It goes without saying that both can be colored (red and green). Of course, the present invention can also be applied to a case where there are two or more developing devices. Further, although an LED array is used as the charge erasing means, means such as a liquid crystal shutter array may also be used.

(Effects of the Invention) As explained above, by arranging at least two color developing units on one photoreceptor, specifying an area, and performing multiple copies of at least two colors, a clear two-color copy image can be produced with simple operations. can be obtained automatically.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of the embodiment, FIG. 2 is a schematic diagram when a document is placed on the document pressure plate, and FIG. 3 is a schematic diagram when the document pressure plate is viewed from above. Figure 4 is a schematic cross-sectional view when the original is placed on the original glass stand, Figure 5 is a schematic view from above when the original is placed on the original glass stand, and Figure 6 is when a digitizer is used. FIG. 7 is a block diagram showing the operation of the developing unit. FIG. 8 is an explanatory diagram of the operation section for specifying an area manually using keys. 1......Photosensitive drum 4...LED array 5...Red developer 6...Black developer

Claims (1)

[Scope of Claims] In a two-color copying device that makes copies of at least two different colors on the same copying material, a first document area specifying means for specifying a first area of a document where a color copy is to be made; a second document area specifying means for specifying a second area to be copied in a color different from the first area in an area different from the first area; a first developing means for developing the first area; and a first developing means for developing the first area; a second developing means that develops a color different from that of the first developing means that develops the area;
or means for controlling only one of the second developing means to act.