JPH01295280A - Image forming device - Google Patents

Abstract

PURPOSE:To always obtain the copy of a photograph which is excellent in gradation by changing a dot pattern according to the developing color of an original. CONSTITUTION:Changing the diameter of dot or changing the density of dots is considered for the dot pattern in case of dot-processing by using a black developing device and a color developing device. For the pale developing color, the pattern of (a) is selected in order to prevent an output image from getting whitish by making white dots inconspicuous or smaller. As the developing color gets dark, the patterns (b) and (c) are selected. A pattern output means makes the dot pattern different according to the developing color specified by a specification means. Thus, the output image can be prevented from looking whitish regardless of the developing color.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus capable of applying halftone dots to an original image.

[Background Art] In recent years, copying machines that can form images of originals in multiple colors have been proposed. In the case of such a copying machine or a so-called analog copying machine that projects the original image onto a photoreceptor and copies it, when copying a photograph, the reproducibility of halftones is poor, so dots appear on the latent image on the photoreceptor. It has been considered that a so-called shaded photographic image may be created by irradiating the image with light.

[The problem that the invention is trying to solve] However,
In the above-mentioned multicolor copying machine, there is a problem in that if a photographic original is printed with halftone dots, for example, in red, the whiteness becomes more noticeable when it is copied in a different color.

There is also the problem that when the image is reduced and copied, the white parts are clogged, resulting in poor gradation, and when the image is enlarged and copied, the image becomes noticeably whitish.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a scanning means for exposing and scanning a document, and forming a latent image on a recording medium according to the document scanned by the scanning means. a pattern output means for forming a halftone dot pattern on the latent image; and a means for specifying a developing color of the document; The silk fortune-telling pattern is different depending on the situation.

Further, a scanning means for exposing and scanning a document, a means for forming a latent image on a recording medium according to the document scanned by the scanning means, and a pattern output for forming a halftone dot pattern on the latent image. and means for specifying an image forming magnification of the document, and the pattern output means changes the halftone dot pattern according to the magnification specified by the specifying means.

[For Use] The above configuration prevents the output image from appearing white regardless of the developed color.

Furthermore, regardless of the magnification, the output image is prevented from appearing white, and an image with excellent gradation is obtained.

〔Example〕

Hereinafter, an embodiment of the present invention will be explained in detail with reference to the drawings. Fig. 1 shows the basic configuration of the embodiment of the present invention. In this figure, a is a first recording means that records an original image on a recording material. b is a second recording means for recording binary character and graphic information on the same recording material as described above.

(Description of Main Body) FIG. 2 shows a schematic internal configuration example of a copying machine to which the present invention is applied. In this figure, 1 is the main body of the copying machine, 2 is the photosensitive drum 2
This is an image forming section centered on 0. Reference numeral 3 denotes a first paper feeding section for feeding the transfer paper SH into the machine, and it includes a cassette 9 that can be detached from the main body and their paper feeding rollers 10.3. ]l,
Sensors S9 to S12. It consists of S23. 4
is a document scanning optical system as a main recording optical system, which includes a lens system for exposing and scanning a document and forming an image on a photosensitive drum 20 and an exposure lamp 24 for illuminating the document;
9, it is driven in the direction of the arrow in the figure. 5 is an original glass table on which the original is placed, 34 is an end thereof, and 6 is a photosensitive drum 2o.
This is a cleaner that removes residual toner from the top.

13a, 13b, and 13c are color developing devices (second developing device) that store color toner such as red; 13D is a developing roller of the developing device; 8 is a black developing device (first developing device) that stores black toner; 8a is a developing roller of the developing device.

The developing devices 13c and 8 selectively apply to the photosensitive drum 20 among the two colors.
The developing device switching solenoid 7 pressurizes (contacts) the photosensitive drum 20 and releases the pressure.

Reference numeral 12 denotes a second roller that supplies the transfer paper SH from the cassette 9 or the second paper feed section 23 to the photosensitive drum 2o in a timely manner according to the image position on the photosensitive drum 20. 3
1 is a primary charger disposed around the photosensitive drum 2o, 15
1 is a transfer charger, 16 is a separation charger, and 28 is a photosensitive drum 2.
A pre-exposure lamp 17 removes unnecessary charges on the image 0, and 17 is a transfer conveyance section. The transfer conveyance section 17 includes a transfer charger 152, a separation charger 162, and a paper conveyance section 17a. 18 is a main motor (DC motor), and photosensitive drum 20. Reference numerals 1, 26, and 27 drive the fixing device 25 with a built-in heater 21, the developing devices 7 and 8, and various transfer paper transport rollers, and 29 is located between the paper ejection rollers 26 and 27. Flappers 29 and 32, which change the path during multiple copying or double-sided copying, are paper discharge trays. 33 is a path for conveying the transfer paper SH fixed by the fixing device 25 to the photosensitive tram 20 again, and 37 is the transfer paper S sent through the path 33.
This is a paper refeed registration roller that takes the H paper feeding timing. Reference numeral 70 denotes a shack for blocking the optical image of the document projected onto the photosensitive drum 20 at a predetermined position.

Furthermore, 90 is a laser unit as an auxiliary recording optical system, which will be explained in detail in FIG. have

In FIG. 3, 94 is a horizontal synchronizing signal (BD double signal detection circuit, 95 is a spherical lens, and 96 is a toric lens. The laser unit 90 erases unnecessary charges outside the image area and detects any location in the image. It is possible to erase or write simple characters on the transfer paper via the photosensitive drum 20. In addition, 5l-312, S14.315.S in FIG.
19 to S23 are various sensors described later.

FIG. 4 shows an example of a circuit configuration of a control system for controlling the copying machine shown in FIG. In this figure, numeral 60 is a control section that controls the entire calculation, and is composed of a microcomputer, a program memory, a RAM (random access memory), a digital logic IC for laser control, a timer, and the like. 61 is an AC driver that controls the AC load 62 such as the exposure lamp 24 and the heater 21; 63 is the main motor 18 and the optical motor 1;
66 is a load such as a solenoid, clutch, fan, etc.; 67 is a document processing device (DF, ADF, RDF) that processes documents, such as automatically feeding documents; 68;
is a sorter. 80 is a warning buzzer, 100 is an operation unit which will be described later in FIG. 5, 180 is a coordinate reading device (editor) for inputting coordinate information, which will be described later in FIG. . Further, AC is an AC power supply, 101 is a power switch, DCP is a DC power supply that supplies power to the control unit 60, etc., and S is sensors S1 to S12. S
14. S15. These are S19 to S23. HVT is a high voltage generator, and includes a primary charger; 31, a transfer charger 15
, separation charger 16, developing roller], 3D, and 8a. In addition to these two devices, the control unit 60
The shutter 70 and laser section 90 described above are also controlled. A font ROM 702 stores stamp data, add-on character data, screen pattern data, and the like.

Next, the operation will be explained.

When the power switch 101 is turned on, first, the heater 21 in the fixing device 25 is energized and waits until the fixing roller reaches a predetermined temperature at which fixing can be performed (wait state).

When the fixing roller reaches a predetermined temperature, the main motor 18
is energized for a certain period of time, and the photosensitive drum 20. The fixing device 25 and the like are driven to bring the rollers in the fixing device 25 to a uniform temperature (weight release rotation). After that, the main motor 18 is stopped,
Waits in copyable state (standby state). Then, when a copy command is input from the operation unit 100, a copy operation starts.

(1) Description of image formation In response to a copy command, the main motor 18 rotates, the photosensitive drum 20 starts rotating in the direction of the arrow, the pre-exposure lamp 28 lights up, unnecessary charges on the photosensitive drum 20 are removed, and 1 High voltage is supplied from the high voltage generator HVT to the next charger 31, and a uniform charge is applied to the photosensitive drum 20. Next, after turning on the exposure lamp 24, the optical motor 19 is driven to expose and scan the original placed on the original glass table 5 in the direction of the arrow, and project it onto the photosensitive drum 20.

At this time, unnecessary images can be removed by the laser unit 90, and any part of the image can be erased or a simple document can be written. In this way, an electrostatic latent image is formed on the photosensitive drum 20.

Next, this latent image is developed by the developer 13c or 8, transferred to the transfer paper SH by the transfer charger 15, and separated from the photosensitive drum 20 by the separation charger 16.

Next, the residual toner remaining on the photosensitive drum 20 is collected by the cleaner 6, and after the charge is uniformly removed by a laser beam from a laser unit 90 that removes unnecessary charges on the photosensitive drum 20, the copy cycle is repeated again.

During the image formation described above, the black developing device 8 and the color developing mold 1
3c, 13a, 13b is the operation unit 10
It is brought into contact with the photosensitive drum 20 by a selection command from 0.

That is, by energizing the developing device switching solenoid 7, the black developing device 8 is released, and the color developing device 13c is pressurized (in contact with) the drum. Further, a developing roller 7a of each developing device,
A developing bias voltage is applied to 8a from a high voltage generator HVT.

In addition, the copying machine of this embodiment can perform not only normal one-sided copying (both-sided copying such as stamp mode, which will be described later), and multiple copying, but the transfer paper that has passed through the -degree fixing device is
The resistance value of the paper and other conditions have changed compared to when copying two sides, and in order to cope with this, the transfer charger 151 and the separation charger 16 are
The conditions for the high voltage applied to the first side and the second side during double-sided copying or multiple copying are also different. These developing biases or high voltage values for one transfer separation are determined by commands from the control section 60.

The optical system 4 is reciprocally controlled by rotating the optical motor 19 forward and backward through the motor control section 63 in accordance with commands from the control section 60 . Sl is a home position sensor of the optical system 4, and the optical system 4 is stopped at the position of this home position sensor S1 during standby. S2 is an image leading edge sensor corresponding to the leading edge position of the original image, and is used for the timing of copy sequence control. Optical system 4
In response to a command from the control unit 60, the scanner reciprocates with a scanning length according to the cassette size and copying magnification.

(2) Transfer paper control S9 in the paper feed section 3 in FIG. Sl, ] are upper and lower paper sensors, respectively, and SIO, Sl, 2 are upper and lower glue position detection sensors, respectively.

Hereinafter, since the upper and lower stages perform similar operations, the paper feeding operation for the upper stage will be explained. First, when the cassette 9 is inserted, an upper cassette size detection sensor (not shown)
The size of the cassette 9 is read and the size of the cassette 9 is identified, the out-of-paper indicator of the operation section 100 is turned off, and the cassette size is selected and turned on.

Next, when the copy operation starts with the copy command,
An upper stage lifter motor (not shown) raises the intermediate plate in the cassette I-9 in advance, and the transfer paper at the position where the intermediate plate detection sensor SIO outputs is fed into the machine by driving the paper feed roller 10.

During the continuous copying operation, when the number of transfer sheets in the cassette decreases and the top surface of the transfer sheet SH drops below a predetermined position, the upper stage lifter motor is turned on in the same manner as described above to raise it to a predetermined height.

The transfer paper fed into the machine reaches the first registration front sensor S7 and is stopped by the registration roller 12, so it forms an appropriate loop and stops. Next, in order to align the leading edge of the image formed on the photosensitive drum 20, the registration roller 12 is driven by a timing signal from the sensor of the optical system 4, and at the same time, after horizontal registration alignment and leading edge alignment, transfer is performed. The paper is sent to the transfer section 17. After the image on the drum 20 is transferred to the transfer paper by the transfer charger] 5 in the transfer section 17, the transfer paper is separated from the photosensitive drum 20 by the separation charger 16 and sent to the fixing device 25 by the paper conveyance section 17a.

In the fixing device 25, the surface of the fixing roller is controlled to a predetermined temperature by a temperature sensor (not shown) placed on the surface of the fixing roller and a heater 21, and the image is fixed on the transfer paper, and then the paper is ejected. The paper discharge is detected by the sensor S4, and the paper discharge roller 26. 27, the paper is discharged to a paper discharge tray 32 outside the machine.

Next, the case of multiple copying will be explained. In the case of multiple copying, the flapper 29 is switched to the position shown by the broken line in the figure by the operation of a solenoid (not shown), and the transfer paper that has been fed, transferred, separated, and fixed in two series is Guided by the flapper 29, the paper passes through the path 33 and is transferred to the second paper feed section 2.
Sent to 3.

Next, in response to a multiple copy command from the operation unit 100, the paper refeed registration roller 37 is rotated, and the transfer paper is sent to the first registration roller 12 section again. Thereafter, the same operation as described above is performed to eject the paper onto the paper ejection tray 32.

In addition, during double-sided copying, the transfer paper is ejected halfway by the paper ejection roller 27 in the same manner as in the above-mentioned normal copying operation, but after the trailing edge of the transfer sheet passes the flapper 29, the paper ejection roller 27 is driven in reverse by a paper discharge motor (not shown), and the transfer paper is guided by a flapper 29 and introduced into a path 33.

The subsequent operations are the same as in the case of double multiple copying. In this way, in the case of double-sided copying, the transfer paper is once taken out of the machine from the ejection roller 27, and the transfer paper is reversed by the reverse drive of the ejection roller 27 driven by the ejection motor (not shown). and sent to the second paper feed section 23.

(Description of Operation Unit) Next, a configuration example of the operation unit 100 will be described with reference to FIG. 5.

In this figure, 101 is a power switch that controls power supply to the copying machine. A reset key 102 operates as a key for returning to the standard mode during standby. 103 is a copy key. Reference numeral 104 is a color developer selection switching key, and this key selects developer 8. 13a
-13c is selected. Numeric keys 105 are used mainly to input the number of copies.

Reference numeral 136 is a recited number entry key, which enables a specific operator to perform the copying operation, and for operators other than those mentioned above, the copying operation is disabled unless a recited number is input using the recited number key. It is possible to prohibit

106 is a key for selecting the cassette 9; 107 is a copy density adjustment key; 108 is a key for selecting the same size copy; 10
Reference numeral 9 indicates a zoom key for specifying the copying magnification in 1% increments, 130 indicates an auto-magnification key for automatically enlarging or reducing the size of the transfer paper, and 110 indicates a fixed magnification for specifying a fixed reduction or enlargement ratio. keys, 111 is a key for specifying border erasure on copy paper, 112 is a key for specifying creation of a binding margin at one end of copy paper, 113 is a key for specifying photo mode for copying halftone images such as photo originals. key, 125 is an area specification key for specifying an area, 126
117 is a kite key for knowing the contents of each function; 131 is a preheating mode key for setting a preheating mode;

114 is a multiple key for selecting multiple mode; 115 is a continuous copy key for dividing the copy area of original glass table 5 into left and right halves and automatically making two copies; 116 is for specifying double-sided copy mode; Key to select, 119. 120 is a key for specifying the operation of the sorter 68; 122°123
and 124 are keys for specifying the mode for writing predetermined character data on the copy image, and specify the date writing, memo writing, and number writing modes, respectively (
127, 128 and 129 are mode memory keys for storing multiple set copy modes;
(Remember street copy mode).

Further, 138 is a liquid crystal display element that displays the number of copies, transfer paper size, set magnification, message, etc.

Reference numerals 139 to 150 are indicators using LEDs (light emitting diodes). First, 139 is a sorter use display LED when the sorter 68 is used, and indicates sort mode, group mode, etc. ] 40 is an automatic exposure adjustment display that lights up when the automatic exposure adjustment (AE) key 137 is pressed; 1
41 is a density display corresponding to the density key 107; 142 is a color developer that is displayed when the developer selection key 104 is pressed and a color developer in the main body or in the optional multiple developer storage device 235 is selected; The color display that corresponds to the color of the developing device lights up. 143 is an auto magnification display that indicates that the auto magnification key 130 has been pressed; 144 is a photo mode display; 145 is a date writing mode display;
46 is an area designation display, 147 is a binding margin mode display, 148 is a memo writing mode display, ] 49 is a frame erasing mode display, and 150 is a number writing display.

(Description of Editor) Next, a configuration example of the editor 180 will be described with reference to FIG. 6.

This editor 180 also serves as a document pressure plate for holding down a copy document, and FIG. 6 shows its appearance. 170 is a document setting surface on which a document is placed when specifying an area;
It is called the coordinate input surface. Reference numeral 171 indicates a reference mark against which the edge of the document is abutted; 186 to 189 are keys for specifying the area specification mode; 185 is a key for storing the specified area; 186 to 189 are keys for storing the specified area in multiple developing devices
A mode selection key is used for copying using two or more of the developing units a, 13b, 13c, and 8; 195 is a clear key for canceling the area specification mode; and 197 is an area specification mode indicator. 190 to 194 are keys for selecting the color of the specified area, and 198 is a display that shows the color of the specified area.

174 to 176 are keys for specifying a character input mode for writing characters on a copy image, 174 is a stamp mode selection key for writing a stamp character selected in the stamp character data input area 177 at an arbitrary position, and 175 is an arbitrary key. An add-on mode selection key 176 is used to write a plurality of characters selected in the character data input area 172, and a screen mode selection key 176 is used to perform halftone dot processing on an arbitrary area. The stamp data input area 177 also serves as an input area for specifying the writing direction of characters to be written, and in this embodiment, two types, vertical and horizontal, can be selected.

1.96 is a display indicating the character input mode, and 173
is a stylus pen which is input by pressing the coordinate input surface 170 when specifying an area or inputting written data. 172. 177 when inputting character data,
This is an input area for specifying the data with the stylus pen 173.

Next, the operation of the editor 180 will be explained.

FIG. 7 shows the configuration of the internal control circuit of the editor 180, where 181 indicates the area on the document set on the coordinate input surface (original setting surface) 170 when the area on the document is pressed down with the stylus pen 173. This is a coordinate reading section that reads the coordinates that have been read, and the coordinates read here are sent to the editor control section 18.
Sent to 4. The editor control unit 184 controls various modes, coordinates, etc. in response to input coordinates according to the control procedure shown in FIGS. 8 and 9, or various key inputs from the key input unit 182 on the editor 180.
Display control is performed on each display section 183 on the editor 180.

Hereinafter, examples of control operations in the editor control unit] 84 in the area designation mode and in the character input mode will be described.

(1) Area designation mode In this embodiment, three types of area designation modes are set, and the contents are as follows.

Mode 1 Mode to copy only within the specified area Mode 2
Mode 3 for copying only outside the specified area Mode for copying with different colors inside and outside the specified area Note that the above-mentioned mode 3 is executed by multiple copying.

The flowchart in FIG. 8 shows an example of the control operation of the editor control unit 184 in the area specification mode using the area specification mode key 186.
The following shows the case where is pressed. First, when the area designation mode key 186 is pressed, the LED of the area designation mode display 197 corresponding to mode 1 is turned on, and the area designation mode of mode 1 is entered (201-1).

Next, when the coordinate input surface 170 is pressed down with the stylus pen 173, the coordinate values of the pressed position are read.

At this time, in this embodiment, an area is specified using the read coordinate values of the two points to form a rectangular parallelepiped with the two points as diagonals.

For this purpose, the coordinates of the two points are read (201-2), and then the data of the coordinate values of the two points read as the first area are transferred to the main body control unit 60 by the key of the area memory key 185, and the main body control unit Stored within 60 (2
01-3). If there is further coordinate input (201-4,
), the same operation as described above is repeated and stored as a second area. In this embodiment, up to eight areas can be stored.

Next, use the color selection keys 190 to 94 to select the developing color within the area specified by the above operation 201-5).
The color data and area specification mode obtained in step 201-5 are sent to the main body control section 60 (201-6).

Here, for example, after two areas are specified, the key 191
When is pressed, red development color is specified for both areas. To specify two areas with different development colors, specify one area, then press the key corresponding to the desired development color, then specify the second area, and press the key corresponding to the desired development color. Just press the key.

(2) Stamp mode In this embodiment, stamps that can be used in stamp mode include "[phase]" and "[phase]" as shown in input area 177 in FIG.
There are three types: I'', F times IlJ, and by selecting one of these and setting the mode on the editor 180, the operator can write at any position on the transfer paper.

The flowchart in FIG. 9(1) shows an example of the control operation of the editor control section 184 in the stamp mode. First, when the stamp mode key 174 is pressed, the corresponding LED in the character input display section lights up and the stamp mode is entered ('
202-1). Next, when the coordinate input surface 170 is pressed down with the stylus pen 173, the coordinate values of the pressed position are read (202-2). Next, it is determined whether the read coordinate value is in the above-mentioned stamp area within the input area 177. If it is outside the stamp area, the stamp will not be input, and if it is within the stamp area, it corresponds to the above-mentioned coordinate value. The same stamp is selected (202-3), the data of the selected stamp is sent to the main body control unit 60, and the data of the selected stamp is sent to the font RO described later.
The stamp mode is read from M702, the selected stamp is displayed on the liquid crystal display section 138 on the operation section 100 on the main body side (202-4), and the operator is asked to confirm the input.

Color selection key 190 to select the development color of the next selected stamp
194, the LED of the display 198 indicating the selected development color lights up (202-5).

Next, use the stylus pen 173 to select either "same" or "same" indicated in the input area 177 as the stamp writing direction (202-6), and arrange the data according to the selected direction. Change (202-6).

Next, enter the stamp writing start position in step 20.
2-7), and determines whether the input coordinate data is within the transfer paper size range (202-8). If it is outside the range, a buzzer installed in the editor 180 sounds a warning sound. and step 2 for re-input.
Return to 02-7. If it is within the range, the coordinate data and the above-mentioned writing direction data are sent to the main body control unit 60 (201-9). Note that the stamp is recorded so that the specified coordinate data is at the center of the stamp.

In this embodiment, three types of stamps are prepared as described above, but the font RO in the laser control 90, which will be described later.
By increasing the memory capacity of M702, it is possible to realize even more types of stamps.

(3) Character input mode Figure 9 (2) shows the character input mode - 1 and time editor control section 1.
84 shows an example of control operation.

First, when the character input mode key 175 is pressed, the corresponding LED of the character input display section 196 lights up, and the add-on mode is entered (203-1).

Next, the stylus pen 173 reads the coordinate values (203-2) in the same manner as in the stamp mode (2), and it is determined whether the read coordinate values are within the input area 172. If it is outside the input area, no characters are input. , if it is within the input area 172,
Character data corresponding to the coordinate values is converted into a character code (203-3).

The converted character code is used to display the above-mentioned input characters on the liquid crystal display section 138 (201) in the same way as in the stamp mode.
4). In this embodiment, up to 40 characters can be input by repeating the above operations (203-5.20
3-7). Note that if the number of input characters exceeds 40, a warning is issued (203-6). When the character input is finished, the above (2)
) Input the development color, writing direction, and writing start position of the characters to be written in the same way as in the stamp mode (203-
8-203-13).

(4) Screen mode I Figure 9 (3) shows editor control section 1 in screen mode.
84 shows an example of control operation. Screen mode key 176
When is pressed, the corresponding LED of the character input display section 196 lights up and the screen mode is entered (20!-1
).

Next, after inputting the development color (204-2), use the stylus pen 173 to specify the area where the screen mode similar to (1) area specification mode described above will be performed (204-3).
). However, if no area is specified, the screen mode is performed on the entire surface of the transfer paper SH.

Note that the stamp mode, character input mode, and screen mode are performed by multiple copying.

Next, various copy modes using the laser unit 90 will be explained.

Note that an image obtained in a normal document copying mode will be described as an analog image, and an image obtained by writing binary data with a laser will be described as a digital image.

Further, in this embodiment, the laser unit 1-90 is used to erase unnecessary charges outside the image area, and the following copy mode 1.

(1) Area-specific copy mode There are eight modes that are combinations of the modes described in the editor 180 above, and FIG. 10 shows an example of copying in area-specific copy mode. Corresponding to each specified mode,
It is possible to copy areas a and b by combining color (copy color) and black 2 image erasure. In the screen mode, a halftone image is created using a digital image in black or color for area a, and normal analog copies are made for both areas a and b.

The eight combination modes are shown below.

■ A mode that copies the inside of the specified area in black ■ A mode that copies the inside of the specified area in color ■ A mode that copies outside the specified area in black ■ A mode that copies outside the specified area in color ■ A mode that copies the inside of the specified area in the first color or A mode that copies the area outside the specified area in black and the second color ■ A mode that copies the area inside the specified area in the second color and the area outside the specified area in the first color or black ■ Adds color halftone dots within the specified area , Normal copy overlapping mode ■ Mode that places black halftone dots in the specified area and overlaps normal copy mode ■ ~ ■ is possible in one copy operation, and ■ ~ ■
This is possible using multiple motes, which will be described later.

(2) Simultaneous copying mode of digital images (characters) and analog images This mode is used to obtain copies as shown in FIGS. 11(A) and (B), and the predetermined area shown with diagonal lines in FIG. 11(C) is It copies (records) digital images.

Here, FIG. 11 (A) shows the date writing mode LED 1.
45 is lit. In this mode, copy start starts the normal analog image copying operation, and at the same time the shack 70 is activated by the solenoid (
(not shown), the edge of the original optical image projected from the original onto the photosensitive drum 2o via the optical system 4 is
Only the shaded area in FIG. 1(C) is cut off, and a digital image (year, month, and date) is written in this shaded area using the laser 90. That is, no document image is formed in the shaded area.

In addition, FIG. 11(B) shows the number writing mode L E
The mode when D 150 is lit is shown, and the image forming procedure of this mote is the same as the case of FIG. 11(A), and the copy numbers are sequentially written as digital images.

Figure 11 (D) is the memo writing mode L E D 14
The image forming procedure in this mode is the same as that shown in FIG. 11(A), and a character string inputted in advance as a digital image is written.

(3) Digital image multiple copy mode This mode is shown in FIG. 11(E), and uses the multiple copy mode to obtain a mixed image of an analog image and a digital image. That is, when a document is set, a character input designation is performed using the editor 180, and the copy key 103 is pressed, the designated character is first copied at the position designated by the editor 180, and then a normal analog copy is performed. Note that it goes without saying that analog copying may be performed first. Note that this corresponds to the character input mode and stamp mode described above for the editor 180.

Each of the motes described above can be used in combination.

Next, the second paper feed section 23 used during screen/multiple copying will be explained. In this embodiment, a second paper feeding section 23 is provided as a transfer paper refeeding mechanism for realizing double-sided copying or multiple copying.

The second paper feeding section 23 is a paper refeeding section essential for realizing double-sided/multiple copying, and when the number of copies is one, there is flexibility in the paper size. However, if two or more sheets of paper are
If you save up to 3, only the paper in the small chair can be stacked.

The control procedure for selecting a paper path during double-sided/multiple copying will be explained with reference to the flowchart in FIG.

When a copying operation is started in response to a copy command from the copy key 103, it is first determined in step 270-1 whether double-sided/multiple copying is to be performed on the same original without replacing the original. For example, if you are copying a certain part of a document in color and other parts in black, select YE.
S (affirmative judgment).

In the case of YES, it is determined in the next step 270-2 whether or not the original is a standard size. If the size is not a standard size, the process advances to step 270-6, and the number of copies is one (selected) unconditionally. If it is a standard size, the process advances to the next step 270-3, where it is determined whether the set number of copies is one, and if YES, the process advances to the above-mentioned step 270-6. On the other hand, if No (negative determination), it is determined in step 270-4 whether the transfer paper size is small, and if No, the process proceeds to step 270-4 described above. If YES, it is determined in step 270-5 whether the set copy number is greater than 20 sheets, which is the maximum number of sheets that can be loaded in the second paper feed section 23, and if YES, the process proceeds to step 270-10, and if No, the process proceeds to step 270-5. Proceed to 270-9. In step 270-6, one copy is made and the copied transfer paper is transferred to the second paper feed section 23.
Then, at step 270-6, the transfer paper is fed again from the second paper feed section 23, copies are made, and the transfer paper is discharged outside the machine. In step 270-10, the number of copies set using the numeric keypad 105 is copied, and the sheets are set in the second paper feed section 23, and in step 270-1
1, the paper is re-fed from the second paper feed section 23, copies are made, the transfer paper is discharged outside the machine, and this routine ends.

Further, if the determination is No in the first step 270-1, step 270-. Proceed to step 12. Step 270-
In Step 12, determine whether the original is a standard size or not, and if No,
At step 270-20, the set number of copies is set to 1, and the process advances to step 270-21. Step 270-12
If YES in step 270-13, it is determined whether the set number of copies is 1 or not, and if YES in step 27
The process advances to step 0-20, and after copying one sheet, the transfer paper is set in the second paper feed section 23.

If No in step 270-13, step 270-1
In step 4, it is determined whether the transfer paper is small size paper or not, and if No, the process proceeds to step 27 (1-20, and the same routine as described above is performed; if YES, the number of copies is determined in step 270-15, If it is 20 (sheets) or more, next step 270
At -16, the set number of copies is set to 20 and the process proceeds to step 270-17. If the number does not reach 20 (copies) or more, the process proceeds to step 270-17.

Next, in step 270-17, step 270-
The set number of copies are made in the same manner as in step 10, and the copied transfer paper is set in the second paper feed section 23.

At the next step 270-18, the original is replaced and a copy command is output, and at step 270-19 a copy is made in the same manner as step 270-9 described above, and this routine ends.

On the other hand, if the size is not the standard size in step 270-12, the set number of copies is set to 1 in step 270-20, copies are made in the same manner as in step 270-5 in step 270-21, and the original is replaced in step 270-22. When the copy command is output, copying is performed in step 270-23 in the same manner as in step 270-11, and this routine ends.

The first question is whether or not double-sided multiple copying with multiple sheets as described above is possible.
Since the sequence program shown in Fig. 2 is automatically executed, the operator does not have to think about it every time, and control is always performed using the optimal system. In addition, in the case of a large number of non-standard copies, it is possible to perform copying one sheet at a time using the second paper feed section 23.

Furthermore, unnecessary problems can be avoided by determining the inconvenience of the transfer paper (such as the size being too small) and discharging it outside the machine without performing double-sided/multiple copy processing.

Next, an example of the circuit configuration of the laser unit 90 is shown in FIG. As shown in the figure, the control unit 60 controls the copy designation area operation unit 100. Copy mode specified by editor 180, copy magnification 9 paper size, photo mode.

Laser unit control information such as add-on character code and add-on position is sent to the laser unit controller 700 via a well-known two-point RA.
Passed via M703. Laser section controller 70
0 is a blank RAM (0) 705° Blank RAM (1) Area data BDATA (described later) for specifying an area is alternately rewritten for each line in 706 according to the program in the external program ROM 701. .

The area data read control circuit 716 outputs a control signal to the blank address counter 715 and the 8-bit shift register 708.
Area data BD from 8 to data control circuit 720
Outputs ATA in 1-bit units.

Blank data RAM (0) 705. RAM (
1) 706 is area data BDA for one line each
It has a configuration that has enough capacity to write TA, and the address position is designated by a blank address counter 715. The laser unit controller 700 writes the area data BDATA into one of the blank RAM (0) 705° and the blank RAM (1) 706.
The address switching circuit 704 and the blank data switching circuit 707 are connected so that the area data BDATA can be read from the other side and written to the 8-hit shift register 708.
Outputs a control signal to.

Next, add-on controls for writing characters, stamps, dates, memos, etc. on copied images will be explained.

According to the control data from the control unit 60, the laser unit controller 700 reads data (character pattern) from the font ROM (character generator) 702 according to the add-on character code, and reads the data (character pattern) from the add-on RAM 72.
Set to 3. The add-on RAM 723 has, for example, 40
It consists of a hit map that can store dot patterns for characters. The laser unit controller 700 writes add-on character printing position designation data indicating the printing position of the character to the add-on controller 709. When the add-on controller 709 receives the start signal from the laser unit controller 700, it sequentially reads data (character pattern) FDATA from the add-on RAM 723 according to the add-on character printing position designation data, and stores the data FDATA.
is output to the data control circuit 720.

As shown in FIG. 3, the light emitted from the laser 91 is reflected by the rotating polygon mirror 93 and is reflected by the imaging lens 95.
．． 96 and scans over the photosensitive drum 20. that time,
In order to extract the horizontal synchronization signal, a horizontal synchronization signal (hereinafter referred to as BD double signal detection circuit 94) is arranged on the laser scanning.

The horizontal synchronizing signal (BD double signal) output from the BD detection circuit 94 is input to the laser unit 90. This horizontal synchronizing signal (BD double signal is input to the pulse width shaping FF (flip-flop) circuit 710 in FIG. 13). After being waveform-shaped, it is input to the pulse synchronization circuit (1) 711. The interrupt terminal of the laser section controller 700 and the pulse synchronization circuit (2) 712.
The horizontal synchronizing signal from the BD detection circuit 94 that is input to the F circuit 710 is called an IBD signal, and the waveform-shaped horizontal synchronizing signal output from the pulse width shaping FF circuit 710 is called an IBD signal.
It is called the D times signal.

The laser unit controller 700 generates an interrupt every time the BD double signal is generated, and blanks the RAM (0) 70.
5. Write area data BDATA to RAM (1) 706. Further, the laser unit controller 700 outputs a control signal in the sub-scanning direction by counting the number of interruptions of the BD double signal and the like.

The pulse synchronization circuit (1) 711 outputs a reset pulse HS Y N C1 to the horizontal synchronization clock generation circuit 713 in synchronization with the rise of the above-mentioned BD double signal. The horizontal synchronization clock generation circuit 713 outputs the tarokk HCLK synchronized with the BD double signal, and is based on the reference clock 5CLK.
The reference clock generation circuit that generates the reference clock 5 and its reference clock 5
It is constituted by a frequency dividing circuit which divides the frequency of CLK according to the input of H3YNCI and outputs the clock HCLK.

Pulse synchronization circuit (2) 712 is horizontal synchronization clock H
BD signal synchronization signal HS YNC based on CLK
Generates 2. The horizontal line counter 714 is cleared by this signal HSYNC2 and counts the horizontal synchronization clock HCLK. horizontal line counter 71
The output of 4 is input to the timing signal generation circuit 718,
A horizontal timing signal is output from the horizontal line counter 714 at the set count number.

Next, the dot erase circuit 71 is used to form a halftone image.
9 will be explained with reference to FIGS. 14-1 to 14-3.

As shown in FIG. 14-1, the dot erase circuit 719
is composed of an 8-bit shift register 724,
As the clock on the shift side, the above-mentioned horizontal synchronization clock H
CLK is being input. That is, halftone dots are formed based on the timing of this horizontal synchronization clock HCLK. 14th
- As shown in the timing chart in Figure 2, the blank signal BLANK indicating the effective image area starts from the rising edge of the BD double signal.
By the rising edge of , halftone dot data is loaded into the shift register 724 via the data north DB by the laser section controller I/roller 700. Note that this load is performed by controller 7.
This is performed based on the load signal LOAD from 00. The output of the shift register 724 is ANDed with the blank signal BLANK by an ant gate 725,
Halftone dot signal DEDATA to data control circuit 720
is output in the form of a dot pattern.

The 8-bit halftone dot data written in the 8-bit shift register 724 by the laser unit controller 700 is cyclically shifted by the synchronous clock HCLK and output to the AND gate 725.

FIGS. 14-3 (A) to (C) show examples of output halftone dot patterns. In the main scanning direction (laser scanning direction), 8-bit halftone data Do' stored in the shift register 724
- A repeat pattern of D7 is output. Regarding the sub-scanning direction (rotation direction of the drum), the laser unit controller 700 transfers (arbitrary) halftone dot data to the 8-bit shift register 724 for each BD interrupt. (For example, D
By loading ATAO-DATA7), a specified (arbitrary) halftone dot pattern can be generated.

The data control circuit 720 of the laser unit 90 receives the character pattern FD from the add-on controller 709.
This gate circuit controls ATA, area data BDATA, and dot data DEDATA from the dot erase circuit 719. That is, the data control circuit 720
For example, character pattern FDATA, halftone dot data DEDA,
TA is selectively output to the laser drive circuit 721 at a predetermined timing. The laser drive circuit 721 modulates the laser using data input from the data control circuit 720.

Next, blank RAM (0) 705 and blank RA
A control operation for controlling a specified image area using M(1) 706 will be described with reference to FIG.

From the control section 60, data (P+, PI') (P2.P2') with area designation as shown in FIG. Now, the blank RAM (0) 705 of the laser unit 90 and the blank RAM (1) 7
06 are each configured to have a storage capacity for one line at a predetermined area resolution. Therefore, when an area as shown in FIG. 15(A) is specified by the control unit 60, three line memory data (area data BDATA) as shown in FIG. 15(B) are used. Next, from the starting point of Po, Xl or line memory data 0 is read from the blank RAM (0) 705. Blank RAM from Xl to X1' (1)
Line memory data 1 is read from 706. ,/
Between X2 and X2, line memory data 0 is read from the blank RAM (0) 705. Furthermore, from X2 to X2
', line memory data 2 is read from the blank RAM (1) 706. From X2' to PE, line memory data O is read from blank RAM (0) 705. As a result, the area (P
1. The area other than P +' ), (P 2 , P 2' ) is irradiated with the laser, and the copied image from the original is in the area (P I+ P+' ) + (''21 P2' )
Only.

Regarding writing of line memory data, the blank RAM that has not been read out is rewritten by the laser section controller 700. Further, when reducing or enlarging, data P l sent from the control unit 60 according to the magnification α
+ P l'+ 2+ Based on p2', p, x
α, P2×α, p, 7xα, P2′×α are calculated, and the line memory data 0. 1. 2 first
Change as shown in Figure 5 (C).

Next, the control procedure of the laser section controller 700 in controlling the designated image area will be explained with reference to the flowchart of FIG. 16. First, in step 800, area designation data and magnification data are received from the control unit 60. Next, in processing step 801, line memory data (area data BDATA) is set in blank RAM (0) 705 from the above-mentioned area designation data and magnification data.

Next, in determination step 802, the control unit 60 waits for an image formation start command to be given. When an image formation start command is given from the control unit 60 in determination step 802, reading from the blank RAM (0) 705 is started in processing step 803.

Next, in processing step 804, blank RAM (1) 7
06, the next line memory data (area data BDAT
A) is set, and in judgment steps 805 and 806 it is judged whether image formation is completed or area data is to be switched.

The end of image formation and the switching of area data are determined by counting the BD double signal from the start of image formation inside the laser unit controller 700, and using that value and Pl.

This is performed by comparing with the sub-scanning position information of Pl' + P2 + P2' + PE.

In the case of area data switching, process steps 806 and 807
The read/write RAM is switched at step 808 and step 809, and step 805 and step 806 are executed.
The process waits for the timing in the same manner as above, and if the determination in step 809 is affirmative, the process returns to step 803, and the above operations are repeated until the image formation is completed.

Next, the photo mode, which is a feature of the present invention, will be explained.

In the photo mode of this embodiment, it is possible to perform torato erase (halftone dot processing) only on a designated area. Torato erase is a technique in which a latent image formed on a photoreceptor is erased in a predetermined dot pattern using a laser beam to form a halftone image.

When performing a trace erase, the logical sum of the area data BDATA and the halftone dot signal DEDATA is determined according to the control signal from the laser section controller.
Make it so that it is input to 1. For example, if you want to halftone only a specific area, set BDATA to 0'' for the specific area, and set BDATA to 1° for the other areas, as in the area specification operation described above.
shall be.

As a result, only the portion corresponding to the specific area has a halftone dot signal D.
EDATA is input manually to the tracer live circuit 721, and the trace erase is performed only in the specific area, thereby forming a halftone image.

or. For areas other than the specific area, the drive signal ``0'' is applied manually to the laser drive circuit 721, and the to-erase operation by laser irradiation is not performed, and the original image is copied as is.At this time, if the trimming mode is not specified, If so, the area other than the specific area is erased by laser irradiation.

FIGS. 17 and 18 show halftone dot patterns when halftone processing is performed using the black developing device 8 and the color developing device 13. Figure 17 shows the halftone dots with different l-diameters.
The figure shows the dot density of the halftone dots changed. For a light developed color, the pattern shown in FIG. 17(a) or FIG. 18(a) is selected to prevent the output image from becoming whitish by making the white dots inconspicuous or small. As the developed color becomes darker, the patterns shown in FIGS. 17(b) and 17(C) or FIGS. 8(b) and 8(C) are selected.

FIG. 19 shows control of halftone pattern selection processing. When the photo mode key 113 is pressed and the copy start key 103 is pressed, it is determined whether the developed color of the original is black or not (901
). Black is Amiko, Hatan (C) (Fig. 17, 1st
8) (903). If it is not black, determine whether it is brown (902), if it is brown, select halftone pattern (b) (904); if it is not brown, that is, one of red, blue, or green, select halftone pattern (a). Select (905). Thereafter, the optical system 4 shown in FIG. 2 starts exposing and scanning the original, and a latent image of the original is formed on the photosensitive drum 20. When the scanning of the optical system 4 reaches the area specified by the editor+80, the erase circuit 719 of the above-mentioned FIG.
The halftone dot pattern selected by the laser beam of the laser device 90 is written as a latent image on the photosensitive tram 2o at the same time as the image of the original, and is developed and transferred with toner, and the tonality is reduced. You can obtain a clear image.

In addition, the following control may be considered as another embodiment.

As shown in FIG. 14-3, FIG. 17, and FIG. 18, since the halftone dot pattern can be selected, the halftone dot pattern can be changed depending on the copying magnification.

No. 20 [71] shows an image obtained by performing halftone dot processing on a document and enlarging and reducing the original. This is an image (C) obtained by uniformly processing the original (A) with a halftone dot pattern of a predetermined size. Moreover, (B) is an image when it is reduced, and the diameter of the halftone dot pattern is also reduced as the B ratio increases. Normally, the white parts of a reduced photographic image are crowded, so a certain halftone dot pattern will result in poor gradation. However, when using a mesh pattern with a smaller dot diameter, as shown in (B), there is an effect of reproducing the clogged white area, and even in a reduced image, it is difficult to obtain an image with sufficient gradation. I can do it.

(D) and (E) are enlarged images; in (D), the dot diameter increases with increasing magnification, and in (j), the dot diameter is kept constant. In both (D) and (E), the ratio of white and black parts is the same, and (D) is more dog-like, so the whitishness is noticeable, deteriorating the image quality. However, in (E), it is possible to obtain good image quality that makes whitishness more noticeable.

In this embodiment, selection control of halftone dot patterns as shown in FIG. 21 is performed so that the user can obtain an image of H-, 4.

When the photo mode is designated, it is determined whether or not to change the halftone pattern based on the magnification (911). This is display section 13
It is also possible to display a message at 8 and let the user select it, or to have the user select it in advance and make the decision based on a flag. If the pattern does not need to be changed, the standard pattern is selected (915). If the pattern is to be changed, it is determined whether to change it only during reduction (912). This judgment is also the same as above. Since this is changed only during reduction, a pattern in which the dot diameter of the halftone dots changes in proportion to the magnification is selected (9+4). If the pattern is to be changed only during reduction, it is necessary to judge whether the specified magnification is to be used or not (913).If the pattern is to be reduced, a diameter proportional to the magnification is selected, and if it is not to be reduced, a standard pattern is selected. Note that instead of changing the dot diameter, the dot density may be changed.

Further, the halftone dot pattern may be selected in combination with the designation of the development color, or other parameters may be considered in the designation of the image forming mode.

[Effects] As explained above, according to the present invention, photocopies with excellent gradation can always be obtained by changing the halftone dot pattern according to the developed color of the original.

Furthermore, by changing the halftone dot pattern according to the magnification, it is possible to always obtain photocopies with excellent gradation.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the basic configuration of the device, FIG. 2 is a sectional view of a copying machine to which the present invention can be applied, FIG. 3 is a diagram showing the configuration of a laser unit, and FIG. 4 is a diagram showing the control configuration of the copying machine. 5 is a diagram showing the operation section, FIG. 6 is a diagram showing the editor, FIG. 7 is a block diagram showing the configuration of the editor, FIG. 8 is a flowchart showing area specification control, and FIG. 1)
~(3) is a flowchart showing the settings of stamp mole~, text mote, and screen mote, respectively.
Figure 0 is a diagram showing an example of copying using area specified copying mode, Figure 11 is a diagram showing a copying example of add-on mode, and Figure 12 is a diagram showing a copying example of double-sided/
Flowchart showing control during multiple copying, Fig. 13 is a block diagram showing the circuit configuration of the laser unit, Fig. 14-1
The figure shows the configuration of the erase circuit, No. 14-2.
The figure is a timing chart of the tiger erase circuit, No. 14.
-Figure 3 is a diagram showing the output pattern of the driver erase circuit.
FIG. 15 is a flowchart showing the configuration of the laser drive circuit, FIG. 16 is a flowchart showing an example of area designation operation by the laser unit controller 1-roller = 1, FIGS. 17 and 18 are diagrams showing halftone dot patterns, Fig. 19 is a flowchart 1 showing the control of the photo mode, Fig. 20 is a diagram showing the screen and 1 image during variable magnification copying in the photo mode, and Fig. 21 is a flowchart showing the control of the photo mode during variable magnification copying. It is a flowchart. 8 is a black developer, 13 is a color developer, 90 is a laser unit, 180 is an editor

Claims (2)

[Claims] (1) A scanning means for exposing and scanning a document, a means for forming a latent image on a recording medium according to the document scanned by the scanning means, and a pattern outputting means for forming a halftone dot pattern on the latent image. and means for specifying a development color of the document, wherein the pattern output means changes a halftone dot pattern according to the development color specified by the specification means. (2) A scanning means for exposing and scanning a document, a means for forming a latent image on a recording medium according to the document scanned by the scanning means, and a pattern outputting means for forming a halftone dot pattern on the latent image. and means for specifying an image forming magnification of the document, wherein the pattern output means varies a halftone dot pattern according to the magnification specified by the specifying means.