JPS626281A - Copying machine with editing function - Google Patents

Abstract

PURPOSE:To make an invariably optimum density adjustment corresponding to editing functions by detecting the density of an original image in a necessary area. CONSTITUTION:A phototransistor PH1 is applied with a specific voltage Vcc from a photosense amplifier 1 through a screened cable and generates a collector current corresponding to the intensity of photodetected light, so the intensity of the original reflected light is detected as the voltage across a resistance R1. An operational amplifier OP and a resistance R2 constitute an amplifying circuit with high input impedance to amplify the voltage across the R1. Its output has its high frequency component removed by a resistance R3 and a capacitor C1 and is outputted to an A/D converter. The A/D converter inputs the outputs of sensors 1-3 at the same time and selects one of them according to a selection signal from a CPU to output digitally-converted original density data.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrophotographic copying apparatus that exposes a photoreceptor to an original image to form an electrostatic latent image and develops it to make it visible. The present invention relates to a copying device with an editing function, a so-called intelligent copier, which performs image processing to select necessary image information on a document in addition to a copying function.

■Conventional technology OA (OFFICE AUTO-MA) in recent years
With the progress of TION, there has been a need to combine the individual functions of OA equipment, ie, copying machines, facsimile machines, word processors, and other equipment. One such trend is the emergence of so-called intelligent copiers, which have an editing function for selecting necessary image information on a document in addition to a normal copying function.

This type of copying apparatus is expected to have the following editing functions.

(1) Sampling function: extracts a part of the original and copies it.

(2) Delete function: Erase part of the original and copy it.

(3) Position change function: Change the position of a part of the original and copy it.

(4) Composite function: Compose and copy multiple originals.

All of these require specifying a specific area on the document and erasing the charge on the photoreceptor corresponding to that area. For example,
It is attracting attention as a function that enables the automatic creation of copies that were previously created by ``cutting and pasting the necessary parts'' in conventional office processing.

However, in order for a copying apparatus having these editing functions to be highly evaluated, it is essential that the copying functions be enhanced.

One of them is automatic density adjustment. This is a function that automatically adjusts the optimum copy density (copy density) corresponding to the density of the original image.

In this case, the density of a portion of the original image is detected, and the copy density is adjusted according to the detected density.

For example, in a typical automatic density adjustment, the density of the background portion of a document image is detected by a density detection means such as a photosensor, and the density control means such as a developing bias power supply is controlled based on this value. In this case, the density detection means is installed at a position corresponding to the vicinity of the periphery of the original image, and detects the density of the vicinity of the periphery of the original image.

By the way, in ``editing'' to cut and paste the necessary parts, the area to be extracted as a copy and the area to be erased may be different, such as when the necessary part is a picture image such as a graph, or if the unnecessary part is extremely dirty. There may be a case where there is a significant concentration difference between the two.

For example, when trying to erase the black frame at the periphery of the original image,
A copying apparatus with an editing function that detects the background density near the periphery of a document image has the disadvantage that the copy density is set to the lightest and the image disappears. In addition, when extracting a colored graph part, a dark copy density is set because the background part is detected as white, resulting in an inconvenience that a solid black copy is produced.

In this way, in conventional copying devices with editing functions, the part that detects the density of the original image is fixed, and the automatic density adjustment function is independent of the editing function, so it is difficult to adjust the copy density appropriately. The problem is that this is not done.

(2) Purpose of the Invention An object of the present invention is to provide a copying apparatus with an editing function that performs automatic density adjustment in response to one editing function.

■Structure of the Invention In order to achieve the above object, the present invention projects an optical image corresponding to an original image onto a photoreceptor to form an electrostatic latent image on the photoreceptor, and develops the latent image to produce a printable image. In a copying apparatus that forms a visual image: image processing area input means for specifying a partial area on a document;
Area setting means for setting an image processing area corresponding to the input of the image processing area input means; static eliminating means for removing static from the photoreceptor corresponding to the area outside the area set by the area setting means; document in the area set by the area setting means A density detection means for detecting the density of the image; a density control means for controlling the copy density; and a control instruction means for instructing the density control means to control the copy density corresponding to the original density detected by the density detection means; do.

According to this, the density of the original image in the area set by the area setting unit is detected by the operator's operation of the image processing area input unit, and the copy density is controlled according to the detected density, so automatic density adjustment becomes an editing function. I can handle it well.

In a preferred embodiment of the invention, the concentration detection means comprises:
The apparatus includes a plurality of optical detection means for detecting the intensity of reflected light from the original image, and selection means for selecting the output of the optical detection means corresponding to the area set by the area setting means.

For example, a plurality of photosensors are optically coupled to an optical scanning system, and the original is scanned (hereinafter referred to as prescan) before exposure starts, and the photosensor output corresponding to the area set by the area setting means is selected. do. Thereafter, a developing bias voltage corresponding to the average value of the selected photosensor output (original image density per unit area) is set to perform automatic density adjustment for copying.

In this case, if the length of the area set by the area setting means in the optical scanning direction is limited to within the distance from the exposure position to the development position, density detection is performed in parallel to the exposure of the photoreceptor (hereinafter referred to as parallel scanning). be able to.

In another embodiment of the present invention, the density detection means includes a plurality of surface potential detection means for detecting the potential of the electrostatic latent image; and the surface potential detection means corresponding to the area set by the area setting means. It shall consist of a selection means for selecting the output of the detection means.

For example, immediately after the exposure position, multiple voltage probes are set to pick up the surface potential of the photoreceptor, and after parallel scanning selects the voltage probe output corresponding to the area set by the area setting means, the average value (unit: The potential of the electrostatic latent image (area) is determined, and the developing bias voltage is set accordingly to perform automatic density adjustment of the copy.

Other objects and features of the invention will become apparent from the following description of an embodiment with reference to one drawing.

FIG. 1 shows the appearance of one type of copying machine embodying the present invention, and FIG. 2a shows its longitudinal section. First, referring to FIG. 1, reference numeral 1 denotes a contact glass for placing an original, 2 a pressure plate for pressing the original from behind, and 42 an operation board.

At the end of the contact glass 1, an X scale 41x extending along the X axis direction indicated by an arrow in the figure and a Y scale 41y extending along the Y axis direction are arranged.

Both the X scale 41
is formed. In this example, each scale has a division of 1
It can be read in mm units.

This will be explained with reference to FIG. 2a. Below the contact glass 1 is a lighting lamp 3. 1st mirror 4. 2nd mirror 5. An optical scanning system including a third mirror 6, a lens 7, a fourth mirror 8, etc. is provided. This optical scanning system is driven for reciprocating scanning in the direction of arrow X and in the opposite direction. Note that the illumination lamp 3. The first carriage on which the first mirror 4, etc. is mounted is connected to the second mirror 5. It moves at twice the speed of the second carriage on which the third mirror 6, etc. is mounted.

The reflected light from the original is guided to the surface of the photosensitive drum 9 through an optical scanning system. Around the photoreceptor drum 9, a charging charger 23. Eraser 24° developer unit 10
．． Transfer charger 19. Separation charger 20. A cleaning unit 22 and the like are provided. The photosensitive drum 9 rotates clockwise in this example.

The surface of the photosensitive drum 9 is first charged to a uniform high potential by the charging charger 23. When the high potential surface is irradiated with light from the document, the potential of that surface changes depending on the intensity of the irradiated light, and this causes the surface of the photoreceptor drum 9 to have a potential distribution according to the image, that is, an electrostatic potential. An image is formed.

Portions where the irradiation light is strong, that is, portions corresponding to the white color of the image, have a low potential, and portions where the light is weak, that is, the portions that correspond to the black color of the image, have a high potential.

As will be described later, the eraser 24 is composed of a large number of light emitting diodes in this example, and by irradiating light onto the corresponding non-image area or image area to be erased on the surface of the photoreceptor drum 9, the potential of that area is increased. Lower it to white level potential. Therefore, even if the area of the photosensitive drum 9 erased by the eraser 24 is irradiated with light obtained from the black image of the original, the potential of that area is at the white level, and a black image will not be reproduced in that area. , this eraser 24 is arranged along the surface of the photosensitive drum 9 in the direction of arrow Y.

The electrostatic latent image on the photoreceptor drum 9 is developed with toner particles attached thereto while passing through a developer unit 10 due to rotation.

In the developing unit 10, a developing sleeve 10a that attracts toner particles in a vertical direction is bent, and as this vertical brush strokes the electrostatic latent image, the toner particles are attracted to areas with high potential. However, since it is not attracted to areas with low potential, a black and white image corresponding to the potential distribution of the electrostatic latent image is reproduced on the photoreceptor drum 9. Further, a forward polarity developing bias voltage is applied to the developing sleeve 10a, and by adjusting this, the density of the copy can be adjusted.

In this example, recording sheets are stored in two paper feed cassettes 11 and 12, and the paper is fed from one of the selected paper cassettes. 13 and 15 are paper feed rollers, 14, 16 and 1
8 is a feed roller, and 17 is a registration roller. The leading edge of the fed recording sheet touches the registration roller 17.
The photoreceptor drum 9 is stopped once in contact with the photoreceptor drum 9, and at a predetermined timing synchronized with the rotation of the photoreceptor drum 9 and scanning of the original image, the registration roller 17 causes the image to overlap with the visible image (toner image) on the surface of the photoreceptor drum 9. sent to.

When the recording sheet passes the position of the transfer charger 19, the visible image on the photosensitive drum 9 is transferred to the recording sheet. When the recording sheet passes through the position of the separation charger 20, the recording sheet is separated from the photosensitive drum 9 and guided to the conveyance path. When the toner image on the recording sheet passes through a fixing unit 21 disposed on the conveyance path downstream of the photosensitive drum 9, the toner image on the recording sheet is fixed to the recording sheet by the heat.

The conveyance path on the downstream side of the fixing unit 21 branches into three. The upper conveyance path is used for reversing the recording sheet, and the lower conveyance path is used as a return path for performing multiple copy processes. The central conveyance path is the paper ejection path. Which conveyance route is used is determined by the state of the conveyance direction control mechanism 31 provided at the branch point. When the return path is selected, the recording sheet is transported to the intermediate tray 34 by the transport rollers 32 and the transport belt 33, and at a predetermined paper feeding timing, the recording sheet is transported to the intermediate tray 34 by the paper feeding rollers 35. The paper is fed to the registration roller 17 via feed rollers 36 and 18. The reversing path is used for single-sided copying and for aligning the sides of recording sheets to be ejected.

FIG. 2b shows in slightly more detail the first carriage carrying the illumination lamp 3; 1st
A mirror 41 reflecting plate and phototransistors PH1 to PH3 are fixed.

The reflection plate is provided with a reading slit and a detection slit. The irradiated light from the illumination lamp 3 is focused on the reading position of the document image (the position of the exposed image) by a reflecting plate, and guided to the photosensitive drum 9 with the reading width adjusted by the reading slit. The irradiation light emitted from the detection slit illuminates the original image in front of the reading position, and the phototransistors PH1 to PH of the original image density detector arranged in the Y direction
3 (only PH1 is shown; the others are installed perpendicular to the page). Phototransistors PHI to PH3
are installed at predetermined intervals on the first carriage and do not condense the irradiation light, so they can receive reflected light from a relatively wide range of original images.In this embodiment, the contact glass 1 Since the length in the Y direction is 300 mm, PH1 is placed at a position of 50 mm, PH2 is placed at a position of 150 mm, and PH3 is placed at a position of 250 mm.

FIG. 2c shows a block diagram schematically showing the document image density detector. The R document density detector is composed of sensors 1 to 3 and an A/D (analog-to-digital) converter.゛Sensors 1 to 3 have the same configuration, and each includes photo sense amplifiers AMPI to AMP3 provided in a sensor and switch unit (described later) and phototransistors PH1 to PH3 mounted on a first carriage.
It consists of Each photo sense amplifier A
Phototransistor PH1 corresponding to MPI to AMP3
It is connected to PH3 through shielded cables. Below is a description of sensor 1.

A predetermined voltage Vcc is applied to the phototransistor PH1 from the photosense amplifier 1 via a shielded cable. Since the phototransistor 1 can obtain a collector current according to the intensity of the received light, the intensity of the reflected light from the original is controlled by the resistor R1.
is detected as the voltage between the terminals. The operational amplifier OP and the resistor R2 constitute a high input impedance amplifier circuit, and amplify the voltage between the R1 terminals. This output is obtained after high frequency components are removed by resistor R3 and capacitor C1.

It is output towards the A/D converter.

The outputs of sensors 1 to 3 are simultaneously input to the A/D converter, but a CPU (microcomputer) 80 (described later)
One of the signals is selected based on the selection signal from , and the digitally converted document density data is output.

FIG. 3 shows the operation board 42. Referring to FIG. 3, the operation board 42 includes a print start key 43. Numeric keypad and clear & stop key 44, density key 45,
47. AE key 462 interrupt key 4A2 50, variable magnification mode key 51, recording sheet (paper) size designation key 52, original size designation key 53.

Input key 54, II collection mode key 559 inversion key 56,
A double-sided key 57 and a display unit 58 are provided. The display unit 58 includes a variable magnification ratio indicator DSPI, a set number display DSP2, and a copy number display DSP3. Each display DSPI, DSP2 and DSP3
is equipped with a 7-segment numeric display with 3 digits each.

As will be described later, special information is displayed on these displays when one editing area is specified.

The duplex key 57 is used to select the path of the recording paper, and the 1 inversion key is used to select whether or not to invert the recording sheet. By operating the 0 duplex key 57 and the inversion key 56, you can select the duplex mode and composite mode. mode.

Single-sided mode, paper ejection mode, re-duplex mode, re-combining mode, blank page mode, double-sided blank page mode, and additional mode can be specified.

Under normal conditions, duplex mode, composite mode, and single-sided mode can be specified. In the duplex mode, a copy is made on a recording sheet fed from a paper cassette, and the copy is inverted and stored in the intermediate tray 34. Therefore, copying is performed on both sides of the recording sheet.

In the composite mode, the recording sheets are stored in the intermediate tray 34 without being reversed. Therefore, recording is performed multiple times on the same surface, that is, images are combined.

The single-sided mode is a normal mode in which a recording sheet on which a copy image is recorded is immediately ejected.

When recording sheets are stored in the intermediate tray 34, other modes can be specified. In the paper ejection mode, the intermediate tray 34
Feed the recording sheet stored in the machine, copy it to it,
Eject the paper. In the re-duplex mode, the recording sheets 1 to 1 stored in the intermediate tray 34 are fed, copies are made thereto, the sheets are reversed, and then the sheets are stored in the intermediate tray 34 again. In the recomposition mode, the recording sheets stored in the intermediate tray 34 are fed, copies are made thereto, and the sheets are stored in the intermediate tray 34 again without being reversed. In the blank paper mode, recording sheets stored in the intermediate tray 34 are fed and immediately ejected without being copied. In the double-sided paper mode, the recording sheets stored in the intermediate tray 34 are fed, and the sheets are reversed without being copied.
It is stored in the intermediate tray 34. In the addition mode, the recording sheets fed from the paper cassette and copied are stored in the intermediate tray 34 with or without being reversed, making it possible to add the missing number of sheets.

If image editing processing is required, press the edit designation key 55.
By pressing the 0 edit specification key 55, you can specify the area. In that input mode, which will be described in detail later,
The editing area can be specified by inputting position information in the X direction and Y direction using the numeric keypad 44 and the input key 54.

4a and 4b show a plan view and a longitudinal sectional view of the eraser 24. FIG. Referring to each episode, the second. The eraser 24 includes a printed circuit board 75, a case 76, a drive circuit unit 77, and a large number of light emitting diodes 78. In the case 76, partition walls 76a are formed at equal intervals of 2 mm, and a light emitting diode 78 is arranged in a space defined by each partition wall. Specifically, here, 150 light emitting diodes are arranged in a line. Therefore, by using this eraser, a 30 cm wide area can be divided into minute areas of 2 mm each, and each minute area can be selectively erased.

FIG. 5 schematically shows the electric circuit of the copying machine shown in FIG. 1.

Please refer to FIG. The main control device is a microcomputer (CPU) 80. System controller 81. Counter 82. Read-only memory (RoM) s3. Read/write memory (RAM) 84° non-volatile read/write memory (NR)
AM) 85. It consists of input/output ports (Ilo) 87, 88, etc.

A battery 90 is connected to the power line of the nonvolatile read/write memory 85 via a backup circuit 86 . A power line from a power supply unit 89 is connected in parallel to a battery 90 via a diode.

Input/output port 87.

Eraser 24 is connected via eraser driver 77 . Input/output port 87 has other inputs.

Separation jam sensor, double feed detection sensor, P sensor.

A toner sensor, a sensor and switch unit including the document density detector, a jam indicator, an operation board (operation panel) 42, and the like are connected.

The input/output port 88 includes a driver that drives various motors, a lamp regulator that controls the illumination lamp 3, a fixing heater control unit, a high voltage power supply unit that supplies a developing bias voltage, etc., a drum heater control unit, and drives various servo motors. A servo motor control unit, clutch, solenoid driver, etc. are connected. A synchronous pulse generator connected to the servo motor control unit outputs a pulse signal synchronized with the rotation of the photoreceptor drum.

Counter 82 is used here to generate control timing for eraser 24. FIG. 6a shows a specific configuration of a circuit including the counter 82 and the eraser driver 77. See Figure 6a. Counter 82 includes two programmable interval timers 93 and 94.

The timers 93 and 94 used here are 8253 (or 8254) manufactured by Intel Corporation.

Simply put, this counter includes three 16-bit counters, and operates in one of six modes depending on the contents of data set in an internal control register. Each mode is
It is as follows.

Mode 0: After setting the terminal count mode, the counter output state is at a low level. When a value is set in the counter, it starts counting the clock input.

When the terminal count is reached, the output state becomes high level and maintains that state.

Mode 1: Programmable One Shot Each timer's gate input functions as a trigger input in this mode. When there is a trigger input, it starts from the next clock.

A wall shot pulse (L active) with a preset clock length appears at the output.

Mode 2: A pulse (L active) at one clock interval is outputted once every n clock inputs according to the value n preset in the rate generator register.

Mode 3: Rectangular wave rate generator Same as mode 2, but outputs a rectangular wave with a count number that is 1/2 of the set rate value.

Mode 4: When the software trigger strobe mode is set, the output is at a high level H, but by setting a value in the count register, the clock input starts counting, and the count up causes pulses at one clock interval (L active) Outputs only once.

In mode 5, the strobe gate terminal of the hardware trigger functions as a trigger, and counting starts at the rising edge of the trigger input. The output goes to low level L only once for l clock intervals during terminal counting.

The count input terminals CLKO, CLKI and CLK2 of each of the three counters (0°1.2) of the programmable interval timer (hereinafter abbreviated as timer) 93 and 94 are connected to the output terminal of an oscillator that generates clock pulses of a predetermined period. It is connected. Counter 0 of timer 93. counter 1
and each gate terminal GATEO of counter 0 of timer 94
, GATE1 and GATEO are commonly connected to the output terminal UT2 of the counter 2 of the timer 94. The gate terminal GATE2 of counter 2 of timer 93 is
is connected to the output terminal 0UT1 of the counter 1 of the timer 9.
Gate terminal GATE 1 of counter 1 of 4 is timer 94
is connected to the output terminal 0UTO of the counter 0 of the timer 9.
4, the gate terminal GATE2 of counter 2 is connected to the power supply line (
+Vcc) IC is connected. The output terminal of the oscillator is connected to the clock output terminal (CLO) via the inverter INVI.
CK), and the output terminal ○UTO of the counter O of the timer 93 is connected to the latch output terminal (LATCH) via the inverter INV2. The output terminal ○UT2 of the counter 2 of the timer 93 and the output terminal 0UTI of the counter 1 of the timer 94 are exclusive OR gates EOR.
The output terminal of the gate EORI is connected to each input terminal of the gate I, and the output terminal of the gate EORI is connected to the signal output terminal (S-
OUT).

Each output terminal (CLOCK) of the counter 82.

(LATCH) and (S-OUT) are respective input terminals (CLOCK) of the eraser driver 7.7.

(LATCH) and (S-IN). The eraser driver 77 includes 19 integrated circuits (Toshiba TD62801P) with the same configuration.
Equipped with CI 9.

As shown in Figure 6b, each integrated circuit consists of an 8-bit shift register, an 8-bit latch, a gate, and a driver, and an output enable control terminal ENABL.
E, latch control terminal LATCH, signal input terminal 5-IN
, clock input terminal CLOCK, reset control terminal RE
SET, a signal output terminal 5-OUT, and an 8-bit driver output terminal. Note that an overlined symbol in the figure indicates that the signal line is L active.

The latch control terminals LATCH of each integrated circuit are commonly connected to the input terminal (LATCH) of the eraser driver 77, and the clock input terminals of each integrated circuit are commonly connected to the input terminal (CLOCK) of the eraser driver 77. . Input terminal of eraser driver 77 (S-I
N) is connected to the signal input terminal 5-IN of the integrated circuit ICI, and is connected to each integrated circuit IC2゜IC3, IC4, IC5,
........., the signal input terminals 5-IN of ICl3 and ICI9 are connected to the respective integrated circuits ICI and ICI9, respectively.
C2, IC: 3. IC4゜・・・・・・・IC17
and is connected to the signal output terminal 5-OUT of rcl 8.

That is, the integrated circuits ICI to IC19 are connected in series, thereby forming a 152-bit shift register as a whole. 150 light emitting diodes LED1 to LED150 (78) of the eraser 24 are connected to the output terminal of each bit via a resistor, respectively. Note that the last two bits are not used here.

Therefore, at the moment the latch signal appears, the bit holding a high level H (which is inverted at the output of the driver) energizes one light emitting diode, and the bit holding a low level L energizes one light emitting diode. Since it is deenergized, signal line 5
By inputting erase information as 150-bit serial data to -IN and applying a latch pulse when the erase is completed, any area of the eraser 24 can be selectively energized.

in one copy cycle. The copyable area on the surface of the photosensitive drum 9 is shown expanded in FIG. 7a. Since the photosensitive drum 9 rotates at a constant speed, the position of the surface of the photosensitive drum 9 in the scanning direction (indicated as the document scanning direction in the figure: X) can be expressed in terms of time when viewed from a fixed position. The vertical direction in the figure is the width direction, that is, the Y direction.

For example, when copying a B4 size original image in an apparatus capable of making A3 size copies, the original image copying area becomes smaller than the copyable area as shown in FIG. 7a. In this case, the area from the edge of the copyable area to the edge of the original image (
From time T1 to T2), leading edge erase (full width erase) is performed, and in the area where the original image exists (time T2 to T5), site erase (erasing areas other than the original width) is performed, and from the rear edge of the original image, the copyable area is erased. Area to the rear end (time T
5 to T6), rear end erase (full width erase) is performed. This is also done in most conventional general copiers.

When erasing or extracting a specific area of the original image for image editing, it is necessary to further erase (erase the electrostatic latent image) within the area of the original image.

That is, FIG. 7a shows the case of erasing an area, in which the area P1 to P2 in one width direction (Y direction) is erased at the scanning direction (X direction) position specified by time T3 to T4. . Since the eraser 24 is arranged to cover the entire area from 0 to M positions along the width direction axis, it is possible to control which area of the eraser 24 the light emitting diodes are energized/deenergized. The erase area in the width direction is determined by .

Furthermore, as described above, since information indicating which region of light emitting diodes to energize is given to the eraser 24 as a serial signal, the erased region in one width direction can also be expressed in terms of time. By controlling the counter 82 shown in FIG. 6a, a signal for energizing the eraser driver 77 can be generated.

FIG. 6c shows the signal timing of each part of the counter a2 for erasing at time T3 shown in FIG. 7a. Note that IC20 and IC21 in FIG. 6c
indicate timers 93 and 94, respectively. 6th
The operation will be explained with reference to figure c.

In order to operate the counter 82, it is first necessary to program each timer 93 and 94. Program setting in this case is performed by the "mode set" subroutine shown in FIG.

In the operation mode, at the timing (erasing) of time 0 time T3 where counters 0, 1 and 2 of the timer 93 are set to 1, 1 and O, respectively, the counters 0, 1 of the timer 93 are
and M, 51-1 in each count register of 2 and 2, respectively.
and S2 (see FIG. 7a), and set Pl-1, P2, and 2 (see FIG. 7a) in the count registers of counters 0, 1, and 2 of the timer 94, respectively.

When the mode setting is completed, the output signal (IC21-0UT2) of the counter 2 of the timer 94 is set to a low level L, and becomes a high level H after counting two pulses. The three counters to which this signal is applied to their gate terminals, 0 and 1 of timer 93 and 0 of timer 94, are triggered from 1 to 1 at the rising edge of the signal and begin counting operations.

Here, since counter 0 of timer 93 is set to mode 5, the output signal (IC20-OUTO) remains at high level H, but counter 1 of timer 93 and counter 0 of timer 94 are set to mode 1. Since it has been
At the falling edge of the next pulse after the gate terminal becomes high level H, those output signals (IC20-OUTI and IC2l
-OUTO) is set to low level L.

Counter 1 of timer 93 has 5l- in the count register.
Since 1 is set, 51-
At the 1st pulse, its output signal (IC20-OUT 1
) is inverted to high level H. The counter 2 of the timer 93 has that signal applied to its gate terminal.

Since mode 1 is set, the output signal (IC20-OUT2) is set to low level L at the fall of the next pulse (S1th pulse) after the signal becomes high level H.

Counter 0 of timer 94 has P in its count register.
Since l-1 is set, at Pl-1st pulse,
Its output signal (IC21-0UTO) is set to high level H. Since the counter 1 of the timer 94 to which the signal is applied to the gate terminal is set to mode 1, the output signal is output at the falling edge of the next pulse (ptth pulse) when the signal becomes high level H. (IC21-00-1
) is set to low level L.

When the P2th pulse appears, the output signal of the counter 1 of the timer 94 (IC21-OUTI) is inverted to high level H, and when the 82nd pulse is cursed, the output signal of the counter 2 of the timer 93 (IC20-0 [IT2) is inverted to high level H. When the Mth pulse appears, since counter 0 of timer 93 is set to mode 5,
An L level pulse of one clock width appears only once in the output signal (IC20-0UTO).

Therefore, two output signals (IC20-0UT2 and IC
21-0υTl) signal 5-O which is the inverted exclusive OR of
A high level H appears at UT for periods corresponding to the number of pulses 0-S1, PI-P2 and S2-M.

Since this signal 5-OUT is read into the shift register of the eraser driver 77 in synchronization with the clock pulse, the number of these pulses corresponds to the position of the light emitting diode of the eraser 24 connected to the eraser driver 77.

Also, since the high level H of the signal 5-OUT means energizing the light emitting diode, that is, erasing the image in that part, this signal causes the 0 to Sl, P in the width direction shown in FIG.
The ranges i to P2 and S2 to M are subject to charge erasure.

The operation explained above is T3 to T4 in the X direction and P in the Y direction.
Although it is assumed that the area specified by 1 to P2 is to be erased, it is also possible to extract the specified area and erase the other areas. That is, in the case of extraction, it is sufficient to invert the signal level (H/L) at the timing of 81 to S2 of 5-OUT shown in FIG. 6C. means. In other words, the output signal of counter 2 of timer 93 (IC20-0UT2
) remains at the high level H during the period 81-S2, the level of the signal 5-OUT during that period is inverted with respect to the state shown in FIG. 6c.

Whether to erase or extract the specified area.

Timer 93.94 program set (mode set)
The content of the program changes slightly as described above, depending on the result of the determination. Details will be described later.

When editing an image, it may be necessary to move a specific area of the image to an arbitrary position.If you use a digital copying machine with a large capacity of memory, data processing makes it easy to move the image. It is possible to do so. However, since this is not possible with an ordinary copying machine, the following method is used in this embodiment.

Since the rotation of the moving photosensitive drum in the X-axis direction is the reference, the scan start timing of the optical scanning system and/or the sheet supply timing of the registration roller 17 are shifted from the standard timing synchronized with the rotation. In other words, if the scanning start timing of the optical scanning system is advanced, the position of the image formed on the photoreceptor drum 9 will move in the negative direction (to the left in the figure) with respect to the document scanning direction (X) in FIG. 7a. If the image is moved and the scanning start timing is delayed, the position of one image moves in the positive direction (to the right in the figure) with respect to the document scanning direction.

In addition, if the sheet supply timing of the registration rollers is advanced, the recording sheet will be shifted to a position ahead of the normal position of the image on the photoreceptor, which is similar to the case where the yK document scanning start timing is delayed. If one image is moved and the sheet supply timing of the registration rollers is delayed, the image will be moved in the same way as when the document scanning start timing is advanced. In this example, when the image is moved by a relatively small distance, only the document scanning start timing is shifted, and when the moving distance is large, the document scanning start timing is shifted. Both timing and sheet supply timing of the registration rollers are shifted.

Movement in the Y direction In this example, the position of the lens 7 provided in the optical scanning system is moved in the Y direction.
This is done by moving it along the axis. The principle of this movement is shown in Figure 7b. That is, in FIG. 7b, when the lens is at the position indicated by the solid line, each part of the document A, B, and C
The light emitted from each part of the document reaches positions A, B, and C on the photoreceptor (inverted image), but when the lens moves to the position indicated by the two-dot chain line, the light emitted from each part of the document A, B, and C becomes , A', B' and C on the photoconductor, respectively, through the optical path indicated by the two-dot chain line.
’ position is reached. That is, by moving the lens, the positional relationship between the image on the document and the image on the photoreceptor is shifted in the Y-axis direction.

Regarding magnification, as in the past, we change the positional relationship between the lens and mirror, adjust the magnification of the entire optical scanning system, and then calculate the difference between the reciprocal of the magnification and the scanning speed of the optical scanning system at the same magnification. Multiplication is performed, and the optical scanning system scans at a speed corresponding to the multiplication result. The amount of movement of the copy image when moving the image in the Y-axis direction is as follows, where d is the amount of lens movement and m is the magnification ratio.

D= (1+m)d In Figures 9a and 9b, a microcomputer (C
An outline of the control operation of PU) 80 is shown.

The operation will be explained with reference to FIGS. 9a and 9b. Note that the numbers of the processing steps to be explained are shown in parentheses.

When the power is turned on, each part is initialized (1), the status of each input port is read (2), and it is determined whether or not it is operable (3). If not ready, check for abnormality (4), and if there is an abnormality, set a display indicating the abnormality (4).
5) Do. After this, until it becomes ready, (2') - (
,3)-(4)-(2)-..., or (2)-(3
)-(4)-(5)-(2)--..., processing is performed in a loop.

When Ready is detected (3), the display indicating an error is reset (6), various parameters in the standard mode are initialized in the specified registers (7), the copy ready display is set (8), and the operation is started. The status of each part (key switches) of the board 42 is read and processing is performed according to the results (9). Check the status of the print start key 43 on the operation board 42 (10) L. If there is no start instruction, then check the status of the edit key on flag (21)
).

This flag is cleared in the initial state.

In that case, return to operation board reading (9) and repeat this operation.

When the edit mode key 55 is operated, either area extraction or area erasure mode is set as the editing mode (
(Registers RB and RE, which will be described later, are set), and at the same time, an edit key-on flag is set. When the edit key-on flag is set, the edit area setting process (22~
32) Execute PR.

In this editing area setting process, first, each coordinate that specifies a rectangular area on the manuscript, that is, the coordinates of the left side of the rectangle (22),
Right hemisphere II (23), inferior hemisphere 1! ? (24) and upper side coordinates (25) are determined. When setting each coordinate, the range of numerical values that can be set is displayed. Numerical values are entered using the numeric keypad 44, and each coordinate is set by pressing the input key 54.

Here, check whether the original size is specified (26)
. If there is no specification, the parameters set so far are memorized for later copying operations, the display contents of each display are returned to the normal state (32), and the operation board is read (9).
).

In addition, if the original size is specified, each step (
The process 27-31) is executed to designate the recording area on the recording sheet, that is, the area where the image read and edited from the original document is to be recorded. In this case as well, each coordinate that specifies a rectangular area on the recording sheet, that is, the coordinates of the left side of the rectangle (27
), right-hand side coordinates (28).

The lower side coordinates (29) and the upper side coordinates (30) are determined. When setting each coordinate, the range of numerical values that can be set is displayed. Numerical values are entered using the numeric keypad 44, and each coordinate is set by pressing the input key 54. When this is completed, copying will be performed in the most favorable condition from the coordinate values input so far.
The magnification ratio and the specified area on the recording sheet are corrected (31).

Detailed processing of the editing area setting processing PR described above.

FIGS. 10a, 10h, 10c, 10d, and 10e show an example of the correspondence between each area on the document placed on the contact glass 1 and each area on the recording sheet. They are shown in Figures 8a and 8b, respectively.

Below, an outline of each representative symbol (indicating the register name) shown in FIGS. 10a to 10e will be explained.

Sx... Length size of the document in the X direction) SY...
Length in the Y direction of the original DX... Length size in the X direction of the recording sheet) DY.
... Length of recording sheet in Y direction X+nin, Xmax, Ymin, Ymax ...
Values to display KIIIin, KIIIax, Ks...
Magnification ratio (lower limit, upper limit).

Setting value) XI, Yl... Input value for area on document (small) X2. Y
2...Input value for the area on the document (large) R3...Document size (enters the value according to the specification, 0 if no specification) RD...Recording sheet size (same as Rs) R.K.
...Input buffer RB, RE...Erase 207 Extraction: I K x, K y...Buffer with variable magnification ratio X3. Y3...
- Input value of area on recording sheet (small) x4. Y4... Input value of area on recording sheet (large) In Fig. 8a, ARI is the contact glass area (readable area: A3
size), AR2 is the document area (B4 size here),
AR3 indicates the editing area specified, and in FIG. 8b, AR4 indicates the recording sheet area (here, A4 portrait), AR
5 indicates a designated recording area, AR6 indicates a recording area after correction processing, and AR7 indicates an unnecessary area.

The region setting processing operation will be described with reference to each episode, along with an example of the region setting operation.

First, reference is made to FIG. 10a. The register R3 is checked to determine whether or not the original size has been specified. If the original size is specified, 0 and original size SX are set in each register Xwin and Xmax, respectively.

If the original size is not specified, Xtsin and Xtaax
0 and DX/Ks, respectively. here,
DX/Ks is the recording sheet size converted to the size on the document reading surface. For example, if the original is 84 size and the recording sheet is A4 size, if 0.82 is selected for the magnification ratio Ks, D
s almost matches the value of the document size SX.

X n+in and X rmax are respectively displayed on the display DS.
Output to PI and DSP3. For example, if the original size is specified and the original size SX is 364 mm (B4 size), O is displayed on the left magnification ratio display DSPI, and 364 is displayed on the right copy number display DSP3.

The value of X min is output to the set number display DSP2 in the center, and the contents of X + oin are set in RK as an initial value.

Check the status of the set key (enter key 54) and the numeric keypad 44, and if the numeric keypad 44 is on, set the value in the register RK, and display the contents on the set number display D.
Set to SP2. A value within three digits is set in register RK. If set key 54 is on, register RK
The contents of are the lower limit value Xll1in and the upper limit value Xll1ax
Check whether it is within the range. If it is outside the range, X min is set as the initial value in the register RK again, an error "E" is displayed on the display DSP2, and the process returns to checking the numeric keypad and set key.

In the example shown in FIG. 8a, the left end coordinates 200 of the editing area AR3 are input from the numeric keypad 44, and the set key 54 is pressed.

If the input value is within the range of X win and X wax, the contents of register RK are stored in register Xi. Therefore.

If the numeric keypad 44 is not operated, the set key 54
When is pressed, the initial value, that is, the coordinates of the left edge of the document, is set in the register Xi.

The above is the details of the process of step 22 shown in FIG. 9b.

Next, the register R3 is checked again to determine whether or not the original size has been specified. If the document size is specified, the previously specified X coordinate value X1 and document size SX are set in each register X win and X max, respectively. If the original size is not specified, use Xwin and Xmax.
Set Xl and Dx/Ks, respectively. Here, DX/Ks is the recording sheet size converted to the size on the document reading surface.

Xm1n and Xl1ax are output to the displays DSPI and DSP3, respectively. For example, if the original size is specified and the original size SX is 364 mm (B4 size), the value of Xl (200 in Figure 8a) will be displayed on the left magnification ratio display DSPI, and the copy number display DSP on the right.
364 is displayed in 3.

The value of X wax is output to the set number display DSP2 in the center, and the content of
).

Check the status of the set key (enter key 54) and the numeric keypad 44, and if the numeric keypad 44 is on, set the value in the register RK, and display the contents on the set number display D.
Set to SP2. A value within three digits is set in register RK. If set key 54 is on, register RK
Check whether the contents of is within the range of the lower limit value Xmin and upper limit value
Set X wax as the initial value in K, and display DSP
Display error rEJ in 2 and return to checking the numeric keypad and set key.

If the input value is within the range of X win and X max, the contents of register RK are stored in register X2. Therefore,
If the numeric keypad 44 is not operated, the set key 54
If is pressed, the initial value, that is, the coordinate 3 of the right edge of the document
64 is set in register X2. In the example of FIG. 8a, the right end of the area AR3 to be specified coincides with the right end (364) of the document area AR2, so it is sufficient to press the set key 54 without operating the numeric keypad 44.

The above is the details of the process of step 23 shown in FIG. 9b.

Next (see FIG. 10b), the register R3 is checked again to determine whether or not the original size has been specified.

If the original size is specified, 0 and original size SY are set in each register Yll1in and Ymax, respectively. If the original size is not specified, set 0 and DY/Ks in Xm1n and Xmax, respectively. Here, DY/Ks is the recording sheet size converted to the size on the document reading surface. For example, if the manuscript is 8
4 size, and the recording sheet is A4 size, the magnification ratio K
If 0.82 is selected for s, DY/Ks almost matches the value of the document size SY.

Y min and Y max are displayed on the display DSPL respectively.
and output to DSP3. For example, if the original size is specified, in the example shown in FIG. 8a, 0 is displayed on the variable magnification display DSPI on the left, and the original size 257 is displayed on the copy number display DSP3 on the right.

The value of Ymin is output to the set number display DSP2 in the center, and the contents of Yn+in are set in RK as an initial value.

Check the status of the set key (enter key 54) and the numeric keypad 44, and if the numeric keypad 44 is on.

The numerical value is set in the register RK, and its contents are set in the set sheet number display DSP2. 3 in register RK
The value within the digit is set.

If the set key 54 is on, it is checked whether the contents of the register RK are within the range of the lower limit value Yll1in and the upper limit value Ymax. If it is outside the range, Y min is again set as the initial value in the register RK, error rEJ is displayed on the display DSP2, and the process returns to checking the numeric keypad and set key.

In the example of FIG. 8a, the lower end coordinates 50 of the editing area AR3 are
Input from the numeric keypad 44 and press the set key 54.

If the input value is within the range of Ywin and Ymax, the contents of register RK are stored in register Y1. Therefore, if the set key 54 is pressed without operating the numeric keypad 44, the initial value, that is, the seat SO at the bottom edge of the document is set in the register Y1.

The details of the process in step 24 shown in FIG. 9b have been described above.

Next, the register R8 is checked again to determine whether or not the original size has been designated. If the original size is specified, the previously specified Y coordinate value Y1 . and set the original size SY. If the document size is not specified, set Yl and DY/Ks in Ymin and Ymax, respectively. here,
DY/Ks is the recording sheet size converted to the size on the document reading surface.

Y n+in and Ymax, respectively, on the display DSPI
and output to DSP3. In the example of FIG. 8a, the value 50 of Yl is displayed on the left magnification display DSPI.

257 is displayed on the copy number display DSP3 on the right side. Output the value of Y max to the set number display DSP2 in the center, and input the contents of Y max to RK as an initial value (257).
Set.

Check the status of the set key (enter key 54) and the numeric keypad 44, and if the numeric keypad 44 is on, set the value in the register RK, and display the contents on the set number display D.
Set to SP2. A value within three digits is set in register RK. If set key 54 is on, register RK
It is checked whether the content of is within the range of the lower limit value Ymin and the upper limit value Ymax. If it is out of range, register R again
Set Ymax to K as the initial value and display 1 display DSP2.
Error "E" will be displayed and the process will return to checking the numeric keypad and set key.

If the input value is within the range of Y min and Y max, the contents of register RK are stored in register Y2. Therefore.

If the numeric keypad 44 is not operated, the set key 54
If is pressed, the initial value, that is, the coordinate 3 of the right edge of the document
64 is set in register Y2. In the example of FIG. 8a, since the upper end coordinate of the area AR3 to be specified is 150, it is sufficient to input 150 from the numeric keypad 44 and press the set key 54.

The above is the details of the process of step 25 shown in FIG. 9b.

See Figure 10c. Whether or not to specify the original size (Section 9b)
Step 26) in the figure is checked by register R8. When the yK document size is specified, the position on the recording sheet side is set as follows. First, register RE is checked to determine whether the editing mode is extraction or erasure. For extraction, set 0 to register X win, and set DX-(X2-Xi) to X
・Set Kmin.

(X2-Xi) Kmin is the size in the X direction on the recording sheet side when the extraction area on the document side set by the above process is copied at the minimum magnification.

If K win is 0.5, then Xmax will be 128 in the example of FIG. 8a and sbm (DX=210).

If deletion is selected, Xm1n is also 0.
Set DX-8X-Kmin for Xmax. If Kff1in is 0.5, then Xm
ax becomes 28 in the example of FIGS. 8a and 8b (DX=210).

Set Xm1n and Xll1ax to DSPI and DSP3 respectively. Therefore, in the example of FIGS. 8a and 8b (extraction case), the left magnification indicator DSPI
0 is displayed, and 1 is displayed on the copy number display DSP3 on the right side.
28 is displayed.

Next, the same process as "left side coordinate input" shown in FIG. 10a is performed. In the example shown in Figure 8b, the left end coordinate of the area to be transferred is set to 50, so the operator can select 50 from the numeric keypad.
, and press the set key 54. In that case, 5
0 (contents of R,) is stored in register X3.

The above is the process of step 27 shown in FIG. 9b.

Next, the contents of register RE are checked again.

In the case of extraction, set X3+ (X2-X 1) ・Kmin to Xrmin.

Xrsax to X3+ (X2-X 1) ・Kmax
Set.

If erasing, set Xm1n to X3+SX-Kmin and Xaax to X3+SX-Kmax.

Therefore, in the example of FIGS. 8a and 8b, if K win is assumed to be 0.5 and K■ ax is assumed to be 2.0 (the same applies hereafter),
In the case of extraction, X min and Xmax are each set to 1
32 (=50+164X0.5) and 378 (=5
0+164X2.0).

However, if Xyaax>DX, DX is set to Xmax. In the above example, Xmax (37g) > D
(210), so update X wax to 210.

X min and X a+ax are respectively displayed on the DSP
Set to I and DSP3. In the example (extraction) of FIGS. 8a and 8b, 132 and 210 are displayed on the displays DSPI and DSP3, respectively.

Next, the same process as the "right side coordinate manual operation" shown in FIG. 10a is performed. In the example shown in Figure 8b, the right end coordinate of the area to be transferred is set to 175, so the operator can press 1 from the numeric keypad.
75 and press the set key 54. In that case, 175 (contents of RK) is stored in register X4.

The above is the process of step 28 shown in FIG. 9b.

Next (see Figure 10d), register RE is checked to determine whether the editing mode is extract or erase.

For extraction, set register Y min to 0 and
DY − (Y 2 − Y 1 ) ・Kmin for ax
Set. (Y2-Y1) Kmin is the size in the Y direction on the recording sheet side when the extraction area on the document side set by the above process is copied at the minimum magnification. Y max is the example of Figures 8a and 8b (DY=2
97) becomes 247.

If erase is selected, Ymin is also 0.
and set DY-8Y-Kmin to Yn+ax.

Set Y min and Y max to DSPI and DSP3 respectively. Therefore, in the example of FIGS. 8a and 8b (extraction case), the left magnification indicator DSPI
0 is displayed on the right side, and the copy number display DSP3↓ko247 is displayed on the right side.

Next, the same process as r"F side coordinate manual effort" shown in Fig. 1 Ob is performed. In the example of FIG. 8b, the lower end coordinates of the area to be transferred are set to 175, so the operator only has to input 175 from the numeric keypad and press the set key 54. In that case, 175 (contents of RK) is stored in register Y3.

The above is the process of step 29 shown in FIG. 9b.

Next, the contents of register RE are checked again.

In the case of lottery 1, set Y3+(Y2-Y1)・Kmin to Ywin,
Set Y3+ (Y2-Yl)・Kmax to Ymax.

If erasing, set Ymin to Y3+SY-Kmin and Yrrrax to Y3+SY-Kmax.

Therefore, in the example of FIGS. 8a and 8b, in the case of extraction, Y win and Yma each have 225 (=1
75+100X0.5) and 375 (=175+10
0X2.0). However, if Ymax>DY, DY is set to Ymax. In the above example, Y+++
ax (375) > D Y (297), so Y
Update max to 297.

Set Ymin and Ymax on the displays DSPI and DSP3, respectively. In the example (extraction) of Figures 8a and 8b, 13
2 and 210 are displayed, "
The same process as ``Upper side coordinate input'' is performed. In the example of FIG. 8b, the upper coordinate of the area to be transferred is set to 275, so
The operator only has to input 275 from the numeric keypad and press the set key 54. In that case, 275 is stored in register Y4.

The above is the details of the process of step 30 shown in FIG. 9b.

In the above steps, the operator sets the area on the document to be edited and the area on the recording sheet to transfer it. But record sea! - It is difficult for the operator to set the upper transfer area at the optimal position (for example, the center of the paper). Therefore.

In this embodiment, the following correction process (step 3 in FIG. 9b) is performed.
1) to reset the transfer area on the recording sheet to the optimum state.

The details of the process are shown in FIG. 10e. This will be explained with reference to FIG. 10e. First, the contents of register RE are checked. For extraction, Kx is (X4-X3)/(X2-X
1) and set Ky to (Y 4-'Y 3)/(Y
2-Y 1 ).

In addition, for erasing, set DX/SX to Kx and D to Ky.
Set Y/SY. That is, the magnification ratios in each axis (X and Y) are set to Kx and Ky, respectively, so that the size of the transfer area on the recording sheet matches the size of the editing area (extraction area or the entire document) on the document.

Then, the contents of Kx and KV are compared and the smaller one is selected. In other words, if KX<Ky, then Kx is the actual magnification ratio Ks
otherwise, set Ky to the actual magnification ratio Ks.

Next, the coordinates of the area on the recording sheet are corrected. This correction is performed only on the axes that were not subject to correction in the magnification change correction described above. In other words, K x < K Y
If it is determined that: The value of Kx is set to Ks, and the Y-axis coordinate is corrected as follows according to the contents of register RE.

For extraction: Y3=Y3+('Y2-Yl)・(1-Ks)/2Y4
=Y4-(Y2-Yl)・(,1-Ks)/2 For deletion: Y3=Y3+SY・(1-Ks)/2Y4-Y4-8
Y・ (1-Ks)/2Kx≧Ky: For extraction: X3=X3+(Xl-Xl)・(1-Ks)/2X4=
X4 (Xl-XI) ・(1-Ks)/In case of 2 elimination: X3=X3+SX・(1-Ks)/2X4=X4-8
X·(1-Ks)/2 and above are the details of step 31 shown in FIG. 9b.

In step 26, when the above processing is completed, including the case where it is determined that the original size is not specified, XI, Xl
,X3. X4. Yl, Y2. Set Y3゜Y4 and s as parameters for the editing process, and display the magnification ratio display D.
The previously set magnification ratio Ks is displayed on the SPI, the predetermined set number is displayed on the set number display DSP2, the initial value 0 is displayed on the copy number display DSP3, and the display is returned to its original state.

After this process, the magnification ratio of the copying machine is determined by the parameter Ks
The timing of the copy operation, that is, the timing of image reading and recording sheet feeding, is set according to the area shift in the X-axis direction (values corresponding to Xi, X3, and Ks), and the lens position is set according to the Y-axis direction. Area deviation (Yl, Y3
and a value corresponding to Ks). Furthermore, the eraser control information is set according to all of these parameters.

Referring again to Figure 9a. When the print start key 43 is pressed in the standby state, a "prescan" subroutine is executed in the AE mode in which automatic density adjustment is performed. "
In the "Prescan" subroutine, the document surface is scanned before exposure to the photoconductor, and for extraction, the average value of the document image density in the specified area (original image density per # area) is calculated, and for erasing, the Find the average value of the original image density outside the area.

Developing bias voltages corresponding to these values are set.

The "prescan" subroutine is shown in FIG.

This will be explained with reference to FIG. In this case, X
i, Yl, Xl, and Y2 represent the coordinates (after correction) of the area on the original specified by the operator, and SX represents the length of the original in the X direction.

After clearing the density register Reg that accumulates density data (voltage values) of the original image, find the coordinates of the center of the specified area, set the Y coordinate (Y1 + Y2)/2 to YO, and set the X coordinate (Y 1
+Y 2)/2 is set as XO (300).

First, the case of extraction will be explained. As mentioned above, phototransistors PH1 to PH3 each have a Y coordinate of 50.150.
, 250, so when YO is less than 100, sensor 1 is selected, and when YO exceeds 100, sensor 1 is selected.
Select sensor 2 when YO is less than 0, and select sensor 3 when YO exceeds 200 (302a to 304), Yl
As for Y2 and Y2, since an error check is performed at the time of input as described above, YO will never exceed 300.

Scanning of the original is started (305). - In this document scanning, the amount of movement of the first carriage is detected by a rotary encoder (not shown) engaged with the optical scanning system, and is indicated by the X coordinate.

When scanning the X coordinate from Xl to Xl, since it corresponds to the extraction area, the already selected sensor output is successively added to the density register Rag (306-308).

Since there is no need to scan the document beyond the X coordinate X2, the scanning is completed and the carriage is driven back to the home position (309).

The value of the density register Reg is determined by the distance between XI and X2 and Y
The average value Va is calculated by dividing the product of the distances between l and 72, that is, the area of the designated area (310), and if Va shows a normal value, the developing bias voltage is set according to this value (310).
11,312). When Va shows an abnormal value, a standard developing bias voltage is set (313).

Next, the case of erasure will be explained. In erasing, the density of the document image in the area that the operator wants to keep as much as possible is detected.

If the center of the Y coordinate of the area to be erased is 200 or more, select sensor 2, and if it is between 100 and 200, select sensor 1.
, and if it is less than 100, select sensor 3 (3
14a-316).

When the center of the X coordinate of the area to be erased is behind the center of the length of the document in the X direction, it is determined that the document image up to the X coordinate X1 should be preserved (317) L, and after starting scanning of the document. (318), and sequentially adds the selected sensor output to the concentration register Reg (318-320). X coordinate X1
After scanning to the position and returning the carriage to the home position, the average value V of the document image density is determined by dividing the value in the density register by the product of Xl and the range for detecting density (for example, 100).

When the center of the X coordinate of the area to be erased is closer to the center of the length of the document in the X direction, it is determined that more of the document image from the X coordinate X2 onwards should be preserved (317), and scanning of the document is started. (323), while scanning from the X coordinate X2 to the trailing edge SX of the document, the selected sensor output is sequentially added to the density register Reg (324-32G). Trailing edge of the document (X coordinate s
After scanning to position x) and returning the carriage to the home position, calculate the average value Va of the document image density by dividing the value of the density register by the product of the distance from X2 to SX (SX - X2) and the detection range. .

A developing bias voltage corresponding to the average value v8 of the document density found in these is set.

When the developing bias voltage is set in the above "prescan" subroutine, steps (10) --(17)
-(1g) -(19) -(20) -(8) -(
9) -... or step (10) -(11) -
(12) -(13) -C14) -(15)
−(16) −(17) −(18) −(19
) −(20) −(13) −(14) −
. . . to proceed with the copy process. "Start cycle processing J (12) performs the processing necessary to start the copy process. Most of the copy process including control of the eraser 24 is carried out in "l Copy processing J
This is done in (13). That is, the timing pulses (not shown) output every minute rotation of the photosensitive drum 9 are constantly counted, and the timing is grasped by checking the value, and the "mode set" shown in FIG. 11 is performed.
By executing subroutines, control is performed according to each timing.

6C, FIG. 7A, and FIG. 11 are referred to.6 Note that FIG. 6C shows only the state of timing T3 in the erase mode, and in FIG. 7A, S2 is the distance or pulse difference with respect to Sl; Note that P2 indicates the distance or pulse difference with respect to Pl, respectively.

The eraser 24 is controlled by the tip erase timing Tl.
It starts from. At this timing TI.

Set the operation mode of each counter 0, 1, 2 of timer 93 and each counter 0, 1, 2 of timer 94, set the numerical value M in the count register of counter 0 of timer 93, and set the count register of counter 2 of timer 94. Set the number 2 to the register. As a result, a pulse appears at the output terminal 0UT2 of the timer 94.

The counter 0 of the timer 93 is triggered at the rising edge, and after M pulses, the output terminal 0UT of the timer 93 is
A pulse appears at O. While the counter 0 of the timer 93 is counting, the output terminal 0UT2 of the timer 93 and the output terminal ○UTl of the timer 94 are both at a high level H, and therefore all bits of the shift register of the eraser driver 77 are eraser-energized. The level is written. That is, until the timer 93 or 94 is reset next time, erasing is performed over the entire width of the photoreceptor.

At timing T2, the contents of the erase mode register RB are checked. If it is 1, that is, extraction, then it is sufficient to continue the full-width erase.

Return without doing anything. When register RB is 0, that is, in the erase mode, each count register of counter 0, counter 1, and counter 2 of the timer 93 has M
, 5L-1 and S2, and the count register of counter 2 of timer 94 is set to 2.

As a result, a pulse appears at the output terminal 0UT2 of the timer 94. At the rising edge of the pulse, counters O and l of timer 93 are triggered. As a result, at the falling edge of the next clock pulse, timer 93 outputs output terminal 0UT1.
goes to a low level L, and then, after an 81-1 clock pulse, its output terminal ○UTI goes to a high level H. The counter 2 of the timer 93 is triggered by this rising edge, and the output terminal 0UT2 of the timer 93 is set to a low level L at the timing of the next clock pulse, that is, SL.

This state continues until the counter 2 of the timer 93 reaches the set value S2. During the period when this output terminal 0UT2 is at a low level L, that is, from 81 to S2, the output terminal 0UT1 of the timer 94
maintains a high level H.

Therefore, the signal line 5-OUT is at a low level, that is, an erase release level appears between 81 and S2.

After that, the output terminal 0UT2 of the timer 93 becomes a high level H, so that the erase level (H) appears again on the signal line 5-OUT. This signal is latched inside the eraser driver 77 by a latch signal appearing at the output terminal UT1 of the timer 93 at the Mth clock pulse.

In other words, in the erase mode, at timing T2, the entire document width (Sl-82
) is excluded from erasing, and therefore only site erasing is performed.

At timing T3, the contents of the erase mode register RB are checked. As a result, if register RB is 0, that is, in erase mode, counters 0, 1, 2 .
M and 5 are input to counters 0゜l and 2 of timer 94, respectively.
l-1, S2. Set PI-1, P2 and 2.

As a result, as described above and shown in FIG. 6c, only the areas corresponding to timings S1 to PI and P2 to S2 are excluded from erasure, and erase and site erase are performed for the specified range of areas P1 to P2. Signal (S-OU
T) is generated.

When the content of the erase mode register RB is 1, that is, the extraction mode, the counter of the timer 93 is set to 0. Counter 0 of timer 94. 1 and 2 count registers, M and P, respectively.
Set L-1, P2 and 2.

When the setting is completed, a pulse appears at the output terminal 0UT2 of the counter 2 of the timer 94, and its rising edge causes the
Counter 0 of timer 94 is triggered, and from the falling edge of the next clock pulse, output terminal 0UTO of counter 0 of timer 94 goes to a low level L for a Pl-1 clock pulse. After counting Pl-1 clock pulses,
When the output terminal 0UTO of timer 94 returns to high level H,
The rising edge triggers the counter 1 of the timer 94, and from the falling edge of the primary clock pulse,
Until timing P2, output terminal 0UT of timer 94
1 is set to low level L.

In this case, counter 2 of timer 93 does not operate.

The output terminal 0UT2 is at a high level H during timing 81 to timing S2. Therefore, the output terminal 0UT of timer 94
A signal similar to that from 1 appears on signal line 5-OUT. In other words, erasing is canceled only from timing P1 to P2.

The signal 5-OUT is output so that only the designated rectangular area remains.

At timing T4, the contents of the erase mode register RB are checked as in the case of timing T2, and timers 93 and 94 are set according to the result. As a result, in the erase mode, a signal (S-OUT) is generated that performs erasure release on the areas 81 to S2 and site erase on the areas 0 to S1 and 82 to M.

In the extraction mode, a signal for erasing across the entire width is generated.

At timing T5, the count register of counter 0 of the timer 93 is set to M, and the count register of counter 2 of the timer 94 is set to 2. After this mode setting, a pulse appears at the output terminal UT02 of the timer 94, and at its rising edge, the counter 0 of the timer 93 is triggered, and after M clock pulses, a latch pulse appears at the output terminal UT0 of the timer 93. In this case, the output terminal 0UT2 of the timer 93 and the output terminal ○
Since UTI is always at a high level H (erase level), all bits of the latch of the eraser driver 77 are set to the eraser activation level.

Therefore, the entire width (rear end) is erased.

Figure 2d shows another embodiment of the invention. In this case, the density of the original image is detected by detecting the potential of the electrostatic latent image formed on the photosensitive drum 9.

The detection probes 1 to 3 are located close to the surface of the photoreceptor drum 9, and are connected to the phototransistor PH1 in the above embodiment.
50°150 and 250 of Y coordinate according to PH3
is placed in a position corresponding to The distance of the detection probes 1 to 3 from the eraser is I2t, which is the circumferential length of the photosensitive drum 9, and is located immediately after the exposure position. These detection probes 1 to 3 are connected to corresponding amplifier circuits 1 to 3, respectively. Since the input impedance of the amplifier circuits 1 to 3 is very high, it is possible to amplify the potential generated in the detection probes 1 to 3 by electrostatic induction caused by the electrostatic latent image.

The outputs of the amplifier circuits 1 to 3 are simultaneously input to the A/D converter, and the A/D converter is given a selection signal from the CPU (microcomputer) 80 to select the input. Select one and output a digital signal indicating the original density.

In FIG. 2d, Q2 represents the distance from the detection probes 1 to 3 to the developing position (drum circumference length), and τ1 represents the time it takes for the surface of the photosensitive drum 9 to move Q1.

Further, τ2 indicates the time it takes for the surface of the photoreceptor drum 9 to move by (11+Q2).

In this embodiment, the control operation of the CPU 80 is different from the previous embodiment (first embodiment) between steps 11a to 14th. First about different parts
This will be explained with reference to the flowcharts shown in FIGS. 3a to 13c. In addition, in this, X3. Y3. X4 and Y
4 is the position* (after correction) of the area on the recording sheet specified by the operator, DY is the length of the recording sheet in the Y direction, X2 is the X coordinate (large) of the area on the document, and
TI, T2. T3. T4 and T5 indicate the timing corresponding to FIG. 7a. Timing T indicates the rotational position information of the photosensitive drum 9 described above.

If the print start key 43 is pressed in step (10) and the AE mode is not selected, steps (400)-(40
6) -(407) -(408) or (/100)
-(406) -(408), and scanning of the original begins.

When extracting a designated area in the AE mode, one of the amplifier circuits 1 to 3 is selected in the same manner as described above.

When erasing a designated area in the AE mode, parallel scanning is performed in this embodiment, so the position and size of the designated area on the recording sheet becomes a problem. That is, when there is a wide erase area (in the Y direction) near the leading edge of the recording sheet, there is little meaning in detecting the original image density at the leading edge.

Therefore, in this embodiment, the distance Q from the leading edge of the recording sheet is
If there is an erase area within 2/2 that exceeds the Y direction width DY/2 (172 of the width of recording sheet 1), set the standard density from the leading edge of the recording sheet to the end of the specified area, and then Automatic density adjustment is performed by detecting the potential of the corresponding electrostatic latent image.

The Y coordinate YO of the center of the specified area is 100≦YO≦
If it is 200, amplifier circuit 1 is selected; otherwise, amplifier circuit 2 is selected (410-411).

Record, the distance heel X3 from the tip of the sheet to the specified area is less than 2272, and the width of the area [4-Y3) is DY/2
When it exceeds r, the "post-detection flag" is set; otherwise, the "post-detection flag" is reset. Thereafter, a start cycle is selected depending on the processing state and document scanning is started (406 to 408). During document scanning, automatic density adjustment control is performed in parallel, but the timing of the specified area is determined by the detection position! There is a delay of τ1 at (positions of detection probes 1 to 3) and τ2 at the development position.

First, we will explain the case of extraction (see Figure 13b).
.

When the length of the specified area (X4-X3) is longer than Q2, the timing T is T3+τ1≦T≦T3 while the tip X3 of the area moves from detection position to detection position.
The density data (potential of the electrostatic latent image) of the original image during the period when +τ2 is sequentially added to the density register Reg, and the width of the area (Y
Divide by the product of 4-Y3) and Q2 to find the average value VB. When the length of the specified area (X4-X3) is shorter than Q2,
During the period corresponding to the length of the region, that is, the timing T is T
3+τl≦T≦T2+τ1 is added to the density register Reg, and the width of the area (Y4−
Divide by the product of Y3) and length to find the average value Va (420~
423). If the value of va is a normal value, a corresponding developing bias voltage is set, and the bias is switched at the timing (T=T3+τ2) when the leading edge of the area becomes the developing position (428°429). The above-mentioned "mode set" subroutine is executed at each timing to perform a predetermined erase, and when the position of the first carriage reaches the rear end position X2 of the specified area on the document, document scanning is finished and the optical scanning system is turned off. Return to home position (430~4
33) When the trailing end erase is completed (434), the process proceeds to the 14th step and thereafter.

Next, the case of erasure will be explained (see Figure 13c).
.

In the case where there is no post-detection flag in AE mode, when the length to the specified area (X3) is longer than Q2, the latent image corresponding to the leading edge of the recording sheet moves from the detection position to the development position, that is, at timing T. is T1+τ1≦T≦
The density data of the original image (potential of the electrostatic latent image) during the time period indicating T1+τ2 is sequentially added to the density register Reg, and the width to be detected (for example).

Divide by the product of 100mm) and Q2 to find the average value Va; when the length to the specified area
2/2 or more) area, i.e.,
While the timing T indicates T1+τ1≦T≦T3+τ1, the density data of the original image is sequentially added to the density register Reg, and divided by the product of the width to be detected and the length to the area to obtain an average value V.

Find (438-442). If this value of v8 is a normal value, set the developing bias voltage corresponding to this,
The development bias is switched at the timing when the latent image corresponding to the leading edge of the recording sheet reaches the development position (2 at T=TI+).
447, 448).

If there is a post-detection flag in the AE mode, a standard developing bias is set up to the rear end of the designated area (454, 445). When the rear end of the designated area becomes the detection position, successive addition of density data to the density register Reg is started. The distance to the latent image corresponding to the rear edge position of the recording sheet is Q
2, the period of Q2 (T4+τ
Calculate the average value v8 of the density where l≦T≦T4+τ2); When the distance to the latent image corresponding to the rear edge position of the recording sheet is shorter than Q2, calculate the average value VB of the density during that time (T4+τ1≦T≦T5+τ1) ( 456-459). If this Va is a normal value, the corresponding developing bias voltage is set, and the timing (T
=T4+τ2) to switch the developing bias (46
0 to 462) shows an abnormal value, the developing bias is not switched and the standard developing bias voltage is applied as is.

The above-mentioned "mode set" subroutine is executed at each timing to perform a predetermined erase, and when the position of the first carriage reaches the rear edge of the original image @SX, the original scanning is finished and the optical scanning system is moved to the home position. Return to (
449-452). After finishing rear end erase (453
), proceed to the 14th step and beyond.

Incidentally, in the first embodiment, the copy density is adjusted by adjusting the developing bias voltage.
Since the first embodiment uses a pre-scan method, the amount of light from the illumination lamp may be adjusted.

■Effects of the Invention As described above, in the present invention, since the operator detects the density of the document image in the area that requires copying, it is possible to always perform optimal automatic density adjustment in response to the editing function. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of one type of copying apparatus embodying the present invention, FIG. 2a is a longitudinal sectional view of the copying apparatus shown in FIG. 1, and FIG.
Fig. 2c is a partially enlarged sectional view showing details of the illumination lamp 3 shown in Fig. 2a, Fig. 2c is a block diagram showing a schematic configuration of the original image density detector of the copying apparatus shown in Fig. 1, and Fig. 2d is a FIG. 3 is a partial cross-sectional view showing the vicinity of the photosensitive drum of another copying apparatus embodying the present invention. FIG. 3 is a partially enlarged plan view showing the operation board 42 of the copying machine shown in FIG. FIGS. 4a and 4b are a plan view and a longitudinal cross-sectional view of the eraser 24, respectively. FIG. 5 is a block diagram showing the electric circuit configuration of the copying machine shown in FIG. 1. FIG. 6a is a block diagram showing the specific configuration of the counter 82 and eraser driver 77 shown in FIG. 5, FIG. 6b is a block diagram showing the configuration of the editing circuit ICI shown in FIG. 6a,
FIG. 6C is a timing chart showing signal states of each part of the counter 82 at a certain timing. FIG. 7a is a plan view showing the relationship between the copyable area on the photosensitive drum and the area included therein. FIG. 7b is a plan view showing the optical positional relationship of the original, the lens, and the photoreceptor. FIG. 8a is a plan view showing each area on the document reading side and their coordinates, and FIG. 8b is a plan view showing each area on the recording sheet side and their coordinates. 9a and 9b are flowcharts showing the general operation of the microcomputer 80 shown in FIG. 5. FIG. 10a to 10e illustrate the process PR shown in FIG. 9b.
FIG. 11 is a flowchart showing the mode set subroutine. FIG. 12 is a flowchart showing the prescan subroutine shown in FIG. 9a. FIGS. 13a to 13c are flowcharts outlining the different operations of the microcomputer 80 shown in FIG. 5 in another embodiment of the present invention. l: Contact glass 2: Pressure plate 3: Illumination lamp 4: First mirror 5: Second mirror 6: Third mirror 7: Lens
8: Fourth mirror 9: Photosensitive drum 10: Developing unit 1 to 10a: Developing sleeve 11.12: Paper feeding cassette 13.15: Paper feeding roller 14.16, 18: Feed roller 17: Registration roller 19: Transfer charger 20
: Separation charger 21: Fixing unit 22: Cleaning unit 23: Charging charger 24: Eraser (# assembly means) 31: Conveyance direction control mechanism 32: Conveyance roller 33: Conveyance belt 34: Intermediate tray 42: Operation board 43 Niblint Start key 44: Numeric keypad (image processing area input means) 52: Recording sheet size designation key 53: Original size designation key 54: Input key 55: &I collection mode key 56 Bi-reverse key 57: Double-sided key 58: Display unit 77: Eraser driver 78, LEDI to LED150: Light emitting diode 80: Microcomputer (area setting means, control instruction means) 82: Counter 91: Document 92: Specified area 93.94: Programmable interval timer DSPI: Magnification ratio display DSP2: Number of sheets set Display DSP3: Copy number display

Claims (3)

[Claims] (1) In a copying device that projects a light image corresponding to the original image onto a photoreceptor to form an electrostatic latent image on the photoreceptor, and develops the latent image to form a visible image: A portion of the original Image processing area input means for specifying an area; Area setting means for setting an image processing area corresponding to the input of the image processing area input means; Static elimination means for removing static from the photoreceptor corresponding to a region outside the area set by the area setting means. ; Density detection means for detecting the density of the original image in the area set by the area setting means; Density control means for controlling the copy density; and Density control means for controlling the copy density corresponding to the original density detected by the density detection means. A copying apparatus with an editing function, comprising: control instruction means for instructing. (2) The density detection means includes a plurality of optical detection means for detecting the intensity of reflected light from the original image; and selection means for selecting the output of the optical detection means corresponding to the area set by the area setting means. A copying apparatus with an editing function according to claim (1). (3) The density detection means includes a plurality of surface potential detection means for detecting the potential of the electrostatic latent image; and selection for selecting the output of the surface potential detection means corresponding to the area set by the area setting means. A copying apparatus with an editing function according to claim (1), comprising means.