JPH02153384A - Compound function copying machine - Google Patents

Abstract

PURPOSE:To keep a machine from being down when a trouble occurs by inverting the logic of an image signal so that countermeasure in regular develop ment is facilitated when a developing device in a reversal developing system cannot be used. CONSTITUTION:In an image writing mode, an image write starting signal is received. Since the reversal development can be performed by deciding whether or not toner exists in the developing device 24, the control of supplying paper, the digital input of an image from an external equipment, the processing of image data, the control of a printing head 71 and the control of a resist roller 37 are performed. Next, whether an image writing action is normal or not is decided. When the action is not normal, the display of error is performed and the machine returns to actions for warming up, the selection of the mode and the setting of a condition. Meanwhile, when it is decided that the toner does not exist in the developing device 24, the machine is switched to a regular developing system. Then, the logic of the image data is inverted, the developing device 25 in a regular developing system is set in a development-enabled state, the polarity of the power source of a transfer charger 26 is made negative and the image is written, whereas the machine is kept from being down.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a multifunctional copying machine having an analog copying function and a digital copying function.

(Prior Art) Copying machines using an electrophotographic process include digital copying machines that copy digital images and analog copying machines that copy analog images.

A digital image in a digital copying machine is obtained by projecting a dot-shaped optical image onto a photoreceptor based on the digital image signal obtained by reading the original image with a photoelectric conversion element and converting it into a binary digital electric signal. It will be done. Digital image signals can be processed by digital electric circuits, so the advantage of digital copiers is that they allow editing such as cutting and pasting images, and they also allow digital image data to be stored and transferred externally. be.

On the other hand, a drawback of digital copying machines is that it is difficult to achieve both halftone reproduction (gradation expression) and resolution. A dither matrix method is generally used to reproduce halftone images, but this method reduces resolution and causes significant image deterioration when copying binary images such as characters. Furthermore, as the resolution increases, the amount of data increases, resulting in a decrease in processing speed and a significant increase in cost. Furthermore, when an image that has been digitally copied is digitally copied again, the image quality deteriorates due to a moiré phenomenon. Further, re-copying a halftone copy using a digital method (generating copy) causes significant image deterioration.

Therefore, at present, analog copying machines and digital copying machines are used depending on the purpose.

Solutions to the disadvantages of digital copying machines include achieving both binary and gradation expression through electrical image processing, compatibility with generation copying by reducing moiré phenomena through filtering, and image quality through higher density. Attempts have been made to improve the processing speed, but each method requires a complicated device configuration, resulting in an increase in cost and a decrease in processing speed.

On the other hand, most documents that are copied in a typical office are binary information such as letters, numbers, and line drawings, and image data with halftones is also treated as hard copies.

Therefore, analog type copying machines have higher cost performance for the work of copying.

Therefore, a multifunction copier that combines analog copying and digital copying functions has been proposed. By using this copying machine, you can use the features of both types depending on the purpose. For example, when recopying a copy using a digital copying method, there is less image deterioration if the copy is made using an analog copying method. Furthermore, it becomes possible to synthesize an analog halftone image and a digital binary image.

For example, an LED head is used as an image writing head for writing digital image data onto a photoreceptor in a multifunctional copying machine. When an LED head is energized to emit light, it generates heat, which affects its lifespan in the long term.

With digital image data, by inverting the logic, it is possible to cause the image area to emit light or to cause the non-image area to emit light. However, since image j) 15 has a smaller area inside the -shell, image 1! Preferably, the head is illuminated. However, when the analog copying function is activated, reflected light from the non-image area is projected onto the photoreceptor. Therefore, if we consider a multifunctional copying machine that utilizes the functions and structure of an analog copying machine as is and is equipped with an image writing head and peripheral circuits, it is not possible to cause the image portion of a digital image to emit light.

Therefore, in another application, the present applicant has disclosed a multifunctional copying machine that uses normal development in analog copying mode and reversal development in digital copying mode.

(Problem to be Solved by the Invention) By the way, in this multifunction copying machine, when the reversal developing type developer cannot be used in the digital copying mode or the image writing mode due to some trouble or empty toner, copying cannot be performed. I can't. However, since this copier also has an analog copy mode, the toner color (for example, black) of the regular development system developer for analog copying and the toner color of the reversal development system developer for digital copying is particularly important. If they are the same, it would be convenient to switch to analog copy mode and copy. Furthermore, digital printing may be used by remote control from the outside, such as output printing from a host computer. In this case, in an emergency when reversal development becomes impossible, it is better to continue printing with regular development, although this is not preferable in terms of heat generation and lifespan of the image writing head. Furthermore, if mode switching is possible, there is no need to prepare a reversal developer for colors that are rarely used.

The copying machine described in Japanese Patent Application Laid-Open No. 56-83757 has a configuration capable of copying by analog positive exposure and writing images by digital negative exposure. Further, the image reading device described in Japanese Patent Application Laid-Open No. 55-123270 uses two optical systems to perform analog writing on a photoreceptor and digital reading using a COD element. However, none of them mention mode switching.

An object of the present invention is to be able to make 6 copies using either analog or digital methods! - To provide a multifunction copier that avoids machine downtime as much as possible when a problem occurs.

(Means for Solving the Problems) A multifunctional copying machine according to the present invention optically scans a photoreceptor on which an acid 1U latent image is formed by exposure and an original on an original placing table, so that the original image is exposed to light. A scanning optical system that projects onto the body, an image sensor placed at a position optically equivalent to the exposure position of the photoreceptor, and an electrical signal from the original image read by the image sensor or an electrical signal from an external device. an image writing head for projecting a dot-shaped optical image onto the photoreceptor; a first developer using a regular development method in which the non-exposed area of the photoreceptor is visualized with toner; A second developing device of a reversal development type that is visualized with toner, a transfer device that transfers the toner image onto paper by applying a voltage, and an analog copy mode using the first developing device, image sensor, image u
a selection means for selecting a digital copying mode using a writing head and a second developing device and an image writing mode using an image writing head and a second developing device; an optical path conversion means for projecting the image onto the exposure position of the photoconductor and the image sensor; and a first phenomenon device when the analog copying mode is selected by the selection means;
copying control means for operating the second developing device when the digital copying mode is selected and setting the polarity of the voltage of the transfer device in accordance with the operated developing device;
This copying control means reverses the logic of the image data input to the writing head and develops it in the first developing device when the second developing device cannot be used in the digital copying mode or the image writing mode. It is characterized by making settings.

(Function) In the multifunction copying machine according to the present invention, when the analog copy mode is selected, the first developing device is activated, the voltage polarity of the transfer device is set corresponding to regular development, and the scanning optical The static 11i latent image of the original image formed on the photoreceptor by the system is normally developed.

When the digital copy mode is selected, the original image is projected onto the image sensor by an optical path converting means (a foldable mirror, a semi-transparent mirror, etc.) and is read and digitized, while the second developing device is operated. At the same time, the voltage polarity of the transfer device is switched to reverse development, and the image writing head performs image exposure on the photoreceptor according to the digitized image data, and the electrostatic latent image formed is removed. is reverse developed.

If the use of the second developing device of the reversal development method is not possible in the image writing mode or the digital copying mode due to i. At the same time, the first developing device of the normal phenomenon type is operated and a voltage of negative polarity is applied to the transfer device.In this way, normal development is performed.

Note that if there is another developing device with the same conditions as the reversal developing type developing device that is no longer usable, it is sufficient to switch to that developing device.

In addition, the current v1. If a reversal developing device with a different color developer (toner) is installed in addition to the device, use another reversing developing device, or use a regular developing device with the same color. The user may be able to select whether to switch to .

Furthermore, by including the case where it is not installed when it cannot be used, if the reversal type developer of the set color developer is not installed, the regular phenomenon type developer of the same color developer of the regular phenomenon is included. can be switched to

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiments) Hereinafter, embodiments of the present invention will be described in the following order with reference to the accompanying drawings.

(a) Overall structure of the copying machine (1)) Analog copying (c) Digital copying (d) Registration control (c) Control system (') Copying flow Note that the digital copying mode or image writing, which is a feature of the present invention, For switching to regular development in mode,
Section (r) will be explained with reference to FIG. 11(c).

(a) Overall configuration of copying machine FIG. 1 shows a schematic configuration diagram of a multifunctional copying machine according to an embodiment of the present invention.

This multi-function copying II utilizes the functions and structure of a normal analog knob type electrophotographic copying machine as it is, and uses the R6 photoreceptor 2 of the multiple reflecting mirrors that make up the scanning optical system.
In addition to making the reflection mirror 14 near the mirror 14 foldable, a line-type CCD (charge coupled device) image sensor 61 for image reading, an LED head 71 for image writing, and peripheral circuits are incorporated. And analog copy mode, digital 1! J, photo mode, image reading mode where the image is read with the COD imager 6I, and image is read with the LED head 7! Equipped with an image writing mode for writing. By adding a communication control unit, it can also be used as a facsimile.

One of the differences from normal analog copying machines is that in addition to the scanning optical system that scans the reflected light of the original in analog copy mode, it incorporates a COD imager 61 and LED head 7I for digital copy mode. It is.

In the analog copy mode, an original placed on a transparent glass original table 2 is illuminated by an illumination lamp 4 in an illumination unit 3. The image of the original is captured by a reflection mirror 5 attached to the illumination unit 3, a reflection mirror 7.8 attached to the mirror unit 6, a scanning lens IO attached to the lens stand 9, and a reflection mirror 12 attached to the mirror unit 11. ,! 3, and by the folding mirror 14 (!
An image is formed on the photoreceptor 21 on the drum by a scanning optical system in which the image is formed.

On the other hand, in the digital copying mode (image reading mode), the optical system from the original 1°t to the image sensor 61 is as follows.
Foldable mirror! The scanning optical system in the analog copy mode is shared by up to 4, and the image sensor 61 is provided at a position optically equivalent to the exposure point on the photoreceptor 21. In the digital copying mode (image reading mode), the collapsible mirror 14 is retracted from the optical path, so that the reflected light from the reflective mirror 13 reaches the image sensor 61 without being obstructed by the collapsible mirror 14. In this way, since the optical path for image reading in digital copying is largely the same as the scanning optical system for analog copying, the apparatus can be simplified.

Another difference from a normal analog copying machine is that the polarity of the transfer voltage by the transfer charger 26 can be set to either positive or negative, and a plurality of developing devices 23, 24, and 25 containing toner of different polarities are provided. That's true. That is, regular development was used for analog copying, and reversal development was used for digital copying. Around the photoreceptor 21, a charger 22, developing devices 23, 24, 25, a transfer charger 26, a cleaning unit 28, and an eraser lamp 30 are arranged as in a normal electrophotographic copying machine. When an electrostatic latent image is formed on the photoconductor 21 which is uniformly negatively charged by the charger 22, a toner image is formed on the electrostatic latent image by the developer 23, 24 or 25. Next, the toner image is transferred onto a sheet of paper by a transfer charger 26. The toner remaining on the photoreceptor 21 is collected by a cleaning unit 28, and then the photoreceptor 21 is irradiated with an eraser lamp 30 to eliminate static electricity. Note that the toner image on the paper is fixed by the fixing roller 43, and the paper is discharged to the discharge tray 47.

In this process, in analog copy mode, the photoreceptor 2
1, since the reflected light of the document is scanned while it is uniformly charged to a negative polarity by the band device 22, a static Ti1t latent image is formed in which the charges of the image portion remain. Therefore, a positively charged toner image is formed on the photoreceptor 21 when developed by the developer 'I'' A23 or 25 having the toner of the positive band 1 (!). Therefore, the polarity of the transfer charger 2G is changed to negative 4 Then,
The toner image is transferred to the paper. On the other hand, in the digital copying mode (or image writing mode), the LED head 71 emits light in the image area on the negatively charged photoreceptor 21, so that the image area's electricity i! ! An electrostatic latent image in which 7 has disappeared is formed. Therefore, the developer 'I with 7u of toner is used.
:) When development is performed using 24, a negatively charged toner image becomes 71
It is formed on the area where i-load disappears (image area). Therefore, when the polarity of the transfer charger 2G is set to positive, the toner image is transferred to the paper.

Note that the seventh ED head 1, which is used in the digital copying mode (and image writing mode), is provided between the charger 22 and the developer 23.

In this embodiment, the paper is fed from the paper cassette 31 or 32 to the transfer unit via the registration rollers 37.

In addition, a paper refeeding system consisting of a gate 45 and transport rollers 51 to 54 is provided, and the fixed paper is fed back to the registration rollers 37.
It was possible to transport up to Therefore, it is now possible to perform composite copying in which dates and other information are written digitally on paper that has been subjected to analog copying. Since analog and digital images can be combined, the range of applications is widened.

In this embodiment, a foldable mirror 14 is used to separate the optical path for digital copying and the optical path for analog copying. However, a semi-transparent mirror can be used instead of the foldable mirror 14. In this case, since the semi-transparent mirror is fixed, no movable parts are required. In analog copy mode,
A part of the light reflected from the original is reflected by the semi-transparent mirror and is reflected onto the photoreceptor 2.
Expose 1. On the other hand, in the digital copy mode, the light transmitted through the semi-transparent mirror is detected by the COD image sensor 61. When writing an image in the digital copying mode, exposure must be performed without exposure from the semi-transparent mirror, so the timings of image reading and image writing are appropriately shifted.

(1.) Analog copying mode Since the copying machine of this embodiment is based on the configuration of an analog copying machine, the operation in the analog copying mode will be explained next.
Each part of the copy 1a will be explained in detail.

The lighting unit 3 and mirror unit in FIG. 1!・6
The location is home. When making an analog copy of a document and when reading an image using the image sensor 6 (described later), the illumination unit 3 and mirror unit 6 of the scanning optical system are moved to the left in the figure at a predetermined speed by a well-known machine groove (not shown). By doing so, the original image is scanned in a slit shape. At this time, the moving speed of the illumination unit 3 and the moving speed of the mirror unit 6 have a 2:1 relationship, and the optical distance from the document surface to the scanning lens 10 is always kept constant.

FIG. 1 shows the position of the scanning optical system when scanning an original image onto the photoreceptor 21 at a magnification of Ill. The speeds are equal.

Although not shown, the lens stand 9 to which the scanning lens 10 is attached is constructed so as to be movable in the left and right directions in the figure, so that the scanning magnification of the original can be changed.

Now, if the scanning magnification of the original is to be doubled, the scanning lens 10 is moved to the 10° position shown by the broken line in the figure. 11 is also moved and mirrors 12 and 13 are placed at positions of 12° and 13°, respectively, as indicated by broken lines, thereby correcting the conjugate length F+Ii.

Furthermore, since the circumferential speed of the photoreceptor 21 is constant regardless of the scanning magnification, the moving speed of the illumination unit 3 is
It is controlled at a speed of /2.

In this embodiment, the photoreceptor 21 is an aluminum driver 1.
An OPC drum whose surface is coated with an OPC (organic photoreceptor) layer is used, and is uniformly charged negatively (=) by a band 7riz22.

When a document image is scanned onto the charged photoreceptor 21, the negative charge on the photoreceptor disappears depending on the intensity of the scanning light. In other words, the charges in the bright parts of the original disappear, and the fI! in the dark parts disappears. The cargo was left behind;
A static TX latent image corresponding to the original image is formed.

Developing devices 23, 24, and 25 for developing the electrostatic latent image with powder toner are arranged around the photoreceptor.

The phenomenon units 23, 24, and 25 are developer! - The color, charging characteristics, etc. of the toner are set differently, and in this embodiment, the developing unit 23 has positive '! ! The developing device 24 contains F-charged red toner, the developing device 24 contains negatively charged black toner, and the developing device 25 contains positively charged black toner.

The developing device 24 containing the negatively charged black I/toner contains a second
As shown in the figure, a protrusion 91 is provided;
When inserted into a fixed position within the library, the interlab switch 93 is accessed. In addition, in the case of the developing device 23, 25 into which positively charged toner is placed, there is a protrusion 9 at the position of the broken line in FIG.
2 is provided, and when inserted into position within the copier 1, a switch 94 is accessed. Therefore, the polarity of the toner can be determined using the switches 93 and 94.

Only one of these developing devices 23, 24, and 25 is enabled to perform development according to an instruction from an operation section (not shown), and the other two are kept in a state in which they do not participate in development.

Assuming that the developing device 25 is selected in the analog copy mode, the negatively charged portion of the electrostatic latent image formed on the photoconductor 21 is developed with positively charged black toner, and the photoconductor 21 A visible image corresponding to the original image is formed thereon. Similarly, when the developing device 23 is selected, a developed image is formed using positively charged red toner. However, when the developer 24 is selected in the digital copy mode, a negative-positive inverted image is formed.

On the other hand, this multifunction copying machine 1 is equipped with paper trays 1-31 and 32 containing copy sheets, which can be selected as required.

Assuming that paper cassette 31 is selected now,
By the pickup roller 33 driven by a signal generated at a predetermined timing! Sheets of paper are in cassette 3
1 and transported by a transport roller 35,
It stops when the tip reaches the registration roller 37.

When the paper cassette 32 is selected, the pickup J-roller 34 is driven, and the paper is transported by the transport roller 36 until it reaches the registration roller 37.

The resist [l-ra 37 is as shown in FIG. 1i
1. It is connected via a clutch 38 to a drive motor (not shown) by a chain 39. The paper 40 conveyed from the paper feed cassette is on standby in a state where it collides with the stopped registration rollers 37.

When the leading edge of the image visualized by one of the developing devices reaches a predetermined position, the registration roller 37 is driven by a control circuit to be described later, and the paper 40 is restarted.

When the paper 40 conveyed by the registration roller 37 comes into contact with the photoreceptor 211.1, it is transferred from the back side to the transfer charger 2.
6, the toner is applied with an electric current of opposite polarity to the toner and brought into close contact with the photoreceptor 21, and the toner on the photoreceptor 21 is transferred onto the paper.

A high AC voltage is applied to the separation jersey 27, whereby the paper is separated from the photoreceptor 21.

Although most of the toner on the photoconductor 2I is transferred to the paper,
A small amount of toner m remains on the photoreceptor 21 without being transferred. This residual toner is scraped off by a cleaning blade 29 installed in the cleaning unit 28 and stored in a collection box (not shown).

In this state, since some charge remains on the photoreceptor 21, the entire surface is exposed by the eraser lamp 30, and the image is returned to the initial state.

The paper separated from the photoreceptor 2I is transferred to the Zakujo unit 4.
1 , is conveyed by a conveyor belt 42 , and guided to a fixing roller 43 .

A heater lamp 44 is installed inside the fixing roller 43 to maintain the roller surface at a temperature necessary to melt the toner. The paper to which the toner has been fixed by passing through the fixing section 43 is normally discharged onto the discharge tray 47 by the discharge roller 46 because the gate 45 is located at the solid line position.

On the other hand, in a mode in which data created on a computer or the like is combined and printed on a normal original, the gate 45 is switched to the position shown by the broken line, so the paper on which the original image has been copied is transferred to the transport roller 5.
1.52, 53.54, and then reaches the reno stroller 37 again and waits.

(C) Digital Copying The above is a description of copying in the normal analog copying mode, but next, image reading and image writing in the digital copying mode will be explained. Note that the case where only image reading is performed is the image reading mode, and the case where only image writing is performed is the image writing mode.

The reflecting mirror 14 in FIG. 1 is of a foldable type,
In the normal analog copying mode, it is at the position shown by the solid line in the figure, and guides the reflected light from the original to the photoreceptor 21, but when reading the original image in the digital copying mode, it is at the position shown by the broken line in the figure. At this time, the reflection mirror 14 is out of the scanning optical path of the scanning optical system, and the original image is formed on the line type image sensor 6.

In this embodiment, the image sensor 61 uses a C0D (charge coupled device) line image sensor. As shown in FIG. 4, this image sensor 61 has 400 light-receiving elements per inch arranged in a straight line, and the total number of elements is about 500Of'1, or the length of the light-receiving part is about 12. It is 5 inches.

When the scanning magnification of the scanning optical system is 1x, the original image is 400D1
A digital scanning lens with a resolution of 1 (dot/inch)! When 0 is at the dashed line position 10', that is, when magnified twice, the resolution is 800 DPl.

In the image sensor 61 shown in FIG. 4, a CCD element 63 is mounted on a ceramic substrate 62, and a transparent protective glass 64 is attached thereon.

Although COD was used as the image sensor element in this embodiment, an image sensor such as amorphous silicon or CDS may also be used.

In FIG. 1, the image sensor 61 is connected to the scanning lens 10.
The optical pressure 1 from the image forming surface of the photoreceptor 21 and the scanning lens I
It is placed at a position that is equal to the distance to O. The scanning optical system from the original to the mirror 13 is the same as in analog copying.

This makes it possible to vary the resolution of document reading by the image sensor 61 by 4 degrees using a control panel that is exactly the same as the control used when changing the magnification during analog copying.

FIG. 5 is a schematic circuit diagram of the image sensor section. Image sensor 6! Then, depending on the amount of light received, the light 771
A conversion is made and this is amplified by amplifier 65. The 8-digit converter 66 converts the amplified analog value for each l dot of the light receiving element into a digital value. In this example, considering the reduction in gradation due to shading correction, 7-bit (
2'=+28 levels).

In general image reading systems, including this embodiment, when a document with uniform density is read, due to unevenness in the light from the illumination lamp, a decrease in peripheral light m due to the scanning lens, and variations in the sensitivity of the reading sensor element, etc. Also, the digital value output from the AD converter 66 is not constant.

Digital values subjected to shading correction are outputted as read image data via the ROMG 7 and RAM 68 for shading correction to correct the influence of variations inherent in the image reading system.

The shading-corrected image data is subjected to halftone processing by an image processing circuit (not shown) or outputted to an external device via an interface unit as necessary, but a description thereof will be omitted here.

FIG. 6 is a schematic structural diagram of the LED head 7■ used as an image writing head in this embodiment, and FIG.
7 is a block diagram of a drive circuit for an LED head 71. FIG.

In the ID head 7I shown in FIG. 6, an LED array 73 is mounted on a ceramic substrate 72 on which a circuit pattern is printed.
And electronic components forming the drive circuit shown in FIG. 7 are mounted. A transparent protective glass 74 is adhered to the upper surface of the LED array 73 to protect the LED array 73 and the wire bonding portion connecting the drive circuit with the LED array 73 from the external environment.

SELFOC lens array 76 has a diameter! A large number of lenses 75 of about +u+ are arranged, and a bit image is formed by scanning a photoreceptor with blinking LED light in response to a manually inputted image signal.

! , the ceramic substrate 72 on which the ED array 73 and drive circuit components are mounted, and the SELFOC lens array 76 are arranged so that the distance between the SELFOC lens array 76 and the LED array 73 is a predetermined distance using fixing fittings (not shown). Fixed.

At this time, an aluminum heat radiating member is attached to the back surface of the ceramic substrate 72 for heat radiation.

In the drive circuit for the LED head 71 shown in FIG.
82 is a parallel shift register that receives the image data of the serial shift register 8I in parallel; 83 latches each image data of the parallel shift register 82; This is a latch register that outputs during the strobe signal output period. Further, a resistor array 84 for limiting the current flowing through the switching element and the LED is connected to the LED array 7.
3 and is connected by wire bonding.

Now synchronize to the image clock! When image data h (serial shift register, star 81) for a line is input, the data in the serial shift register 8I is transferred to the parallel shift register 82 by a shift signal, which is a horizontal synchronization signal, and the data of the next line is transferred to the serial shift register 81. Shift register 8! is manually powered.

The next shift signal causes the data in the parallel shift register 82 to be transferred to the latch register 83, the second line data is shifted to the parallel shift register 82, and the third line data is transferred to the serial shift register 83.
! is input.

When a strobe signal set to the time width for lighting the LED is input manually, L1? , D array 73 is switched.

In this way, the LED-D based on the image data for each I line
The lighting of the array 73 is controlled to form a bit image on the photoreceptor.

Margin below (d) Registration control Next, the electrostatic latent image formed on the photoreceptor 21 is transferred to the copy paper.
The timing of registration control for transferring to the second predetermined position will be explained.

Since data writing methods and exposure positions are different between analog copying and digital copying, the timing of registration control for transferring the image formed on the photoreceptor 21 to a predetermined position on copy paper is different.

In the case of analog copying control (see FIG. 13), the timer value for driving the clutch 38 of the registration roller 37 (FIG. 3) is determined by the leading edge force of the document image (on the photoreceptor 2I) in FIG. When rotated from the exposure position gia point to the transfer position point, it is set so that it coincides with the leading edge of the printing area of the paper 40 (Fig. 9).In other words, the exposure position corresponding to the angle section C in Fig. 8 The time is up when the leading edge of the original image moves from the exposure position gla by the distance H (12c - 12,) obtained by subtracting the distance MQ from the registration roller 37 to the transfer point from the distance #Ill!c on the body. Specifically, this is carried out by starting a timer (1) on a switch (not shown) activated by the movement of the lighting unit 3 and counting clock pulses synchronized with the movement of the lighting unit 3. .

The distance that the illumination unit 3 moves while moving by the leading edge of the document image (Qc - Qυ, that is, the distance that the exposure point on the document moves from the operating point C of the timer activation switch to the drive timing of the registration roller 37 I2. differs depending on the scanning magnification of the optical system, so the timer value is calculated according to the copying magnification.

When the timer times up, the clutch 38 is driven and the paper 40 is conveyed by the registration rollers 37, but the timing at which the paper 40 reaches the transfer point is the same as the timing at which the leading edge of the image reaches the transfer point. for,
The leading edge of the image on the transfer paper and the leading edge of the paper match.

In this embodiment, since the registration timer counts clock pulses synchronized with the movement of the illumination unit 3, it is necessary to calculate the timer value in accordance with the copying magnification. However, if the system is different from the one that starts at the moment when the leading edge of the document starts being exposed and counts clock pulses synchronized with the rotation of the photoreceptor 21, the speed of the photoreceptor is constant, so correction calculations using the scanning magnification are necessary. No, start switch position variation, timing roller 37
It is only necessary to correct positional variations, etc.

On the other hand, in the case of digital copy control (see FIG. 14), a timer different from the timer used for analog copy control is started at the start of printing, as will be described later. When the timer expires, the registration roller latch 38 is driven, and the paper 40 is conveyed by the registration roller 37.

At this time, the timer value is L El) Head 7! on the photoreceptor 21! The distance from the printing point to the transfer point, that is, the 8th
Distance ρf1 on the photoreceptor corresponding to angle section d in the figure
In contrast, the tip of the printed image is C(ld-(1,-α)
It is set so that the count is incremented at the point when the distance has moved. As shown in FIG. 9, α is the margin () when the print area is set to be a little smaller than the paper 40.

Also at this time, hli corrections such as variations in the position of the print head 71 and variations in the position of the registration rollers 37 occur.

(c) Control System FIG. 1O is a control diagram of the cash function copying machine of this embodiment.

The body system that is also dimensioned by the CPU (C)
- The controller 101 includes an operation panel controller 105, a subsystem controller 102, an image processing processor 111,
It is connected to input/output interface controllers 112 and 113 via control signal communication lines 121 and 122, and performs management control of the entire system.

The subsystem controller 102 controls each part in the stepper copying machine according to the commands from the overall system controller 101.
4.115, and transmits these statuses to the overall system controller 101.

The mechanical controller 103 controls the area around the photoconductor and the paper feeding system table device based on a preset control program according to commands from the sub system controller 102, and also reports the status of each part to the sub system controller 102. . For example, the developer 23.
The access status of the photointerrupter switches 93 and 94 provided for each of 24 and 25 is monitored by the mechanical controller 103, and is transmitted as a status report to the subsystem controller 102 and further to the overall system controller 1011.

The scanning optical system controller 104 reports the control of each part of the scanning optical system and the status of each part to the subsystem controller 102 in response to a command from the subsystem controller 102 . Specifically, blinking and light amount control of the illumination lamp 4, scanning control of the illumination unit 3 and mirror unit 6,
Scanning lens based on copy magnification! 0 and mirror unit 11
control the position and calculate the scanning speed.

Operation panel control [1-ra! 05 reports the status of switches (including mode setting switches) operated by the operator to the overall system controller 101, and controls the lighting of various indicators according to commands from the overall system controller lot.

The image sensor controller 114 controls the image sensor 6I according to a command from the subsystem controller +02.
The image processing unit 111 takes in an image signal from the computer and performs specified processing on it by an image processing processor Ill.

LEI) The head controller 115 controls the image processing processor 11 according to the instructions from the subsystem controller 102.
! , or input interface controller +12
The image data is captured by the LED head 71, and the image is written by the LED head 71.

Also, based on the information from the subsystem controller 102, it performs the inversion of negative and positive, calculation of an image area corresponding to the paper size, and editing of image data based on this.

The image processing processor 111 controls the image sensor controller 1 based on the commands from the overall system controller 101.
The image data sent from 14 is processed with halftones using a specified dither pattern, compressed, and output ■/1? output to the controller 113,
LI? : Output to D head controller [l-ra 115 and print directly (digital copy).

Also, human power 1/I? Restoration processing and the like of image data taken in from the controller 112 are performed.

The output ■/F controller 113 is the overall system control [
Communication control with external equipment is performed according to commands from the 1-ra 101, and image data processed by the image processing processor 111 is output to the external equipment.

′ Human power! /F controller 112 controls communication with external equipment according to commands from overall system controller 101, imports image data from external equipment, and
In order to convert the data into data that can be printed by the ED head 71, the captured data is processed by the image processing processor 1.
Send it out on 11th.

Control signal lines 121 and 122 connected to the overall system controller 101 are lines for communicating control commands and status status.

Signal line 1 connected to Zabu system controller +02
236f+, I+ is a line for communicating control commands and status status, and includes a timing signal for defining control timing.

Signal line 13 for exchanging control signals with external equipment
The image signal lines 1, 132 and 133/13/I for transmitting and receiving image data are selected depending on the external device.

The image signal line 135°1 from the image sensor 61 and the image signal line 13G to the E-head 71 are image signal lines for serial data, and the other image signal lines 137, 138,
139.140 uses an 8-bit parallel data image signal line.

In FIG. 10, the range surrounded by the dashed line is the base analog system control block, and by using this as it is, the multifunctional multifunction multi'1:j machine is constructed. The operation panel controller 105 is connected to the Zabu system controller +02 by a control line 12B in the Ana (J) M machine.

The entire system controller 101 controls the access status of the photointerrupter switches 93 and 94! - Composite printing can be controlled based on operation information from the operation panel controller 105. For example, computer data can be printed on paper on which an analog copy of an original image has been made.

That is, the combination data taken in from the data line 131 is sent to the photoreceptor 21 by the LED head 71.
When the registration roller clutch 38 is activated (FIG. 14), the LE
Computer data created by the D head 71 is transferred.

(f)) Summer Photo Flow FIGS. 11(a), (b), and (c) show the control flow of the overall system controller 101. The processing when a 1-rubble occurs during digital copying (image writing) and the reversal phenomenon becomes impossible, which is a feature of the present invention, is as follows:
Step S73 in FIG. 11(c). S82.891~S
93. S')G to S98.

When the main switch (not shown) is pressed and power is supplied (step S! (hereinafter "step" will be omitted))
, initial settings are performed (S2), then a check of the device is performed (S3), and it is determined whether the device is normal (S4). If it is not normal, an error message is displayed on the operation panel (not shown) (S5).

If the device is normal, mode selection and condition setting are performed in parallel according to the settings on the software and operation panel.

4--z,, up (S11) until completed (
(YES in S12) is carried out. When the process is completed (4), the process advances to 345 and the device is activated.

On the other hand, mode CM) is selected on the operation panel (S
21). The modes include analog copy mode (M=I) and image reading mode (M=2), as will be explained later.
, image writing mode (M=3), digital copy mode (M
=4). Next, the operating conditions of the subtraction machine are determined by mode νJ
If the condition is the same as the period condition (YES in S22), or if the condition is not the same but does not match the mode (No in S23).
) sets initial conditions for each mode (S24).

Then, the process advances to S41. On the other hand, if the condition matches the mode (YlεS in S23), the process directly advances to S41.

Further, conditions such as the paper feed cassette are set on the operation panel (S31). Then, it is determined whether the condition is suitable for the mode (532), and if not, a warning that the condition is inappropriate is displayed on the operation panel (533), S31
Return to If the mode is compatible, the process advances to S41. In the table,
The setting conditions for each mode are shown below.

In the margin table mode and setting conditions S41 below, the apparatus is set (including the settings of the developing device and transfer charger for normal development or reversal development, which is a feature of the present invention) based on the above mode/condition settings (S4
1, see Figure 12). Then, a check is made to see if the device is normal (S42). If it is normal, proceed to S.15 and start up the device. If it is not normal, an error message is displayed (S44), and then the process returns to Sl 1 and S21.831 to perform resetting.

When the device is activated (S45), the process proceeds to FIG. 1L (V)), the selected mode (M) is checked, and branching occurs accordingly (S4G).

In the analog copying mode (M=1), first, the illumination lamp 4 is controlled, the photoreceptor 21 is driven, the electrophotographic process system is controlled, the transport system is driven, and the constant 1° 1 part is controlled (
S51). Next, paper feed control (S52), setting of the foldable mirror and scanning of the optical system (S53), registration roller 3
7 control (S54, see Figure 13) and optical system return (S55) are operating normally (YES at 956).
) until the end (YES in S57), and after the end, the process returns to Sll, S2+, and S31. If it is not operating normally (No at 356), an error is displayed (S44)
, Sll.

Return to S2t and S31.

In the image reading mode (M=2), communication is performed with an external device (host computer, etc.) (SGI), and upon receiving a signal to start image reading, the illumination lamp 4 is controlled (S (
i2), initialize the successor route (SG3).

Then, the foldable mirror 14 is retracted, the scanning optical system scans the document (S64), and the image sensor 61 performs image reading, image processing, and data output to external equipment (S65).

When image reading is completed, a completion signal is sent to the external device (
S6G), the illumination unit 3 of the scanning optical system and the mirror unit G are returned to their original positions (SG7).

Next, it is determined whether or not image reading has been completed normally (SG
8). If it ends normally, Sll, S21, S3t
Return to If the process has not ended normally, an error is displayed (S44) and the process returns to Sll, 521 and S31.

In the l1Iiii image writing mode (M=3), FIG.
) As shown in J-, the photoreceptor 21 is driven and the electrophotographic plate c1
Controls the processing system, drives the conveyance system, and controls the fixed pipe section (S
? +), communicates with an external device (post convenience store L-Yu, etc.) (S72), and receives a signal to start image writing.

Next, it is determined whether or not there is toner in the developing device 24 (S
73). If it is determined that there is toner, reversal development can be performed, so paper feeding control (S74), image data input from external equipment, processing of image data, and control of the print head 71 (S74) are performed.
S75), control of the rhenostroller 37 (876, 13th
(see figure lid).

Next, it is determined whether the image writing operation is normal (S?
? ). If it is not normal, an error will be displayed and then C844)
, S l l, S21. Return to S31. If normal,
Next, communication is performed with an external device (S7B), and it is determined whether or not image writing is completed (S79). If not finished, S7
Return to step 4 and perform the next stroke (44t'J included).

If finished, SI 1. S21. Return to S31.

On the other hand, if it is determined that there is no toner in the developing device 24 (No in S73), the copying machine is immediately stopped.

First, processing that is a feature of the present invention is performed. In other words, since this restoration machine is also capable of regular development, image writing is performed using regular development. So, in order to switch to the regular development method,
Reversing the logic of the image data (591), developing the normal development method 'a:'i 25 into the developable state Cera 1-L (S
92), make the polarity of the voltage of the transfer charger 26 negative (
S93), and then proceeds to S74. In this way, when there is no toner and the reversal phenomenon cannot be performed, it is switched to the normal phenomenon, and S7
Return to step 4 and write the image to avoid machine failure.

In the digital copying mode (M=4), first, the illumination lamp 4 is controlled, the photosensitive drum 21 is driven, the electrophotographic process section is controlled, the transport system is driven, and the constant section 11 is controlled (
S8 Ri. Next, it is determined whether or not there is toner in the developing device 24 (S82). ! - If it is determined that there is a color difference, reversal development can be performed, so paper feeding is controlled (S83), the foldable mirror I4 is retracted, the document is scanned by the scanning optical system (S84), and the image sensor 61 The image is read in, the image data is processed, and writing by the print head 71 is controlled (S85), and the registration roller 37 is controlled to feed the paper (886, see FIG. 14). If scanning is completed, the illumination unit 3 and mirror unit 6 of the scanning optical system
Return to its original position (S8?). The next question is whether the digital copying is working properly or not. Ii is determined (38B). If it is not normal, after displaying an error (S44),
S21. Return to S31. If it is normal, it is then determined whether the digital copying is finished (S89). If it is not completed, the process returns to S83 and the next copy is performed. If the process is finished, the process returns to S11°S2+ and S31.

On the other hand, if it is determined that there is no toner in the developing device 24 (
If S82 is No), the copying machine is not stopped immediately, but the processing that is a feature of the present invention is performed. By the way, this copying machine is also capable of regular development, so digital copies are made using regular development. Therefore, in order to switch to the regular development method, the logic of the image data is reversed (59G), and the developer 2 of the regular development method is
5 to a developable state (597), and the polarity of the voltage of the transfer charger 2G is set to negative (S98). And S8
Proceed to step 3. If reversal development cannot be performed due to lack of toner, the process is switched to regular development, the process returns to S83, and image writing is performed to avoid machine failure.

Note that if reverse development is not possible due to a problem other than toner empty, you can similarly switch to the normal phenomenon.

Further, a warning may be displayed so that the user can select whether or not to perform the switching.

FIG. 12 shows the control regarding the developing device and the transfer chamber 1-jar in the above apparatus cellar 1-(S41).

First, it branches (Slot) depending on the mode (M). M=
1 (analog copy mode), either one of the regular developing devices 23 and 25 is set to a developing state. In other words, if it is a black and white image, the black toner developer 25
If it is set (S+03), or not (color copy), it is red! - The developer device 23 of the toner is set to a developing state (S104). Then, the transfer charger 2G is set to negative polarity (S105).

In addition, in the case of M=3 (image writing mode) and M-4 (digital copying mode), since reversal development is performed, it is necessary to set the reversal developing device 24 to a developing state (5ill), and transfer charger 26. Make the polarity positive (S I 12).

FIG. 13 shows the flow of registration control (S54) in analog copy mode. First, calculate the timer value (already explained using FIG. 8) for driving the electromagnetic clutch 38 (512I) and start the timer (S+22). Then, start the timer to keep time. 5123), when the timer counts up (S
YES at +24), the clutch 38 is driven (S125
), the paper is transported.

Further, FIG. 14 shows the flow of registration control in the digital copy mode (S8G) and the image u) included mode (S7f3). Wait for printing to start (YES in S141),
Timer timing is performed by setting another timer value as described above with reference to FIG. 8 (S l 42). Then, when the timer counts up (YES at S143), the clutch 38 is driven (S+4/I) and the paper is conveyed.

Below are the margins (effects of the invention) When a reversal developing type developer cannot be used in image writing mode or digital copying mode due to a problem such as empty toner, the logic of the image signal is reversed and normal development can be used. Made it possible to avoid being knocked down. Particularly when printing received image data under the control of an external device, six prints can be made with regular development in an emergency when a problem occurs with a developing device or the like during printing.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a multifunction copying machine. FIG. 2 is a perspective view of the developing device. FIG. 3 is a perspective view of the resist [J-RA]. FIG. 4 is a perspective view of the CCl) image sensor. FIG. 5 is a block diagram of the image reading circuit. FIG. 6 is a perspective view of the LED head. FIG. 7 is a circuit diagram of the LED head. FIG. 8 is a diagram for explaining the timing of registration control. FIG. 9 is a diagram showing the meaning of α. FIG. 1O is a block diagram of the control system of the multifunctional copying machine. Figure 11 (a), (b), (c), Figure 12,
FIG. 13 and FIG. 14 are flowchart 1 of the control of the overall system controller. ! ...Multifunction copying machine, 14...Foldable reflective mirror 21...Photoreceptor, 23.25...Reversal development system development 2: (,24...
Regular development method phenomenon 2:), 2G...transfer chart, 61...COD imager, 7! ...L E I) Head, 101... Whole system controller. Patent Applicant Minolta Camera Co., Ltd. Agent Patent Attorney Haka Aoyama

Claims (1)

[Claims] (1) A photoconductor on which an electrostatic latent image is formed by exposure; a scanning optical system that optically scans the document on the document table and projects the document image onto the photoconductor; and an exposure position of the photoconductor. An image sensor placed at an optically equivalent position, and an image sensor for projecting a dot-shaped optical image onto a photoreceptor in response to an electrical signal of a document image read by the image sensor or an electrical signal from an external device. an image writing head, a first developer using a regular development method in which the non-exposed area of the photoreceptor is made visible with toner, a second developer using a reversal development method in which the exposed area of the photoreceptor is made visible with toner, and a voltage. a transfer device that transfers a toner image onto paper by applying a toner image; a selection means for selecting an image writing mode using a developing device; an optical path conversion means for projecting a document image onto an exposure position of a photoreceptor and an image sensor in accordance with the mode selected by the selection means; Copying control that operates a first developing device when a copy mode is selected and a second developing device when a digital copying mode is selected, and sets the polarity of the voltage of the transfer device in accordance with the operated developing device. means, the copy control means inverts the logic of the image data input to the writing head when the second developing device cannot be used in the digital copying mode or the image writing mode, and the copying control means inverts the logic of the image data input to the writing head. A multi-function copying machine characterized by being set to perform development with.