JPH1195520A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color image forming device whose size is reduced by disposing a plurality of laser scanning means so that a part of one laser scanning means covers a part of another. SOLUTION: The laser-beam scanner units 227 (227a-d) are arranged so that a part of the laser-beam scanner unit 227 situated upstream in the direction of the carrying of paper P covers a part of the laser-beam scanner unit situated downstream in the direction of the carrying, and so that photoreceptor drums 222 (222a-222d) which are subjected to the scan of images in their respective colors with the laser-beam scanner units have the fixed lengths of laser-scan optical paths from their respective laser-beam scanner units. A transfer carrying- belt 216 is disposed below the photoreceptor drums such that its upstream side in the direction of the carrying of the paper P is put in a low position and its downstream side in the direction of the carrying is put in a high position. A fixing means 217 is disposed downstream in the direction where the transfer carrying-belt carries the paper P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image signal input means for inputting a color image signal, and scans a laser beam modulated in accordance with each color image signal input by the image signal input signal. A plurality of laser scanning means, and a plurality of image recording means for recording a color image corresponding to an image signal of each color by being scanned by the laser scanning means. The present invention relates to an image forming apparatus that reproduces a color image by sequentially transferring the color images formed in (1) to a transfer material.

[0002]

2. Description of the Related Art In a color image forming apparatus, for example, a color digital copying machine, a color image is output from a printer after a predetermined image processing is performed on an image of a document input from a scanner.

For example, Japanese Patent Publication No. 1-45632 discloses an image of a color original which is separated by a color CCD and read, and the read color separated image of the color original is stored in a memory and then recorded while sequentially reading out. A color image forming apparatus that reproduces a color image in a unit is described.

In the color image forming apparatus described in this publication, a color separation image of a color original read by a color CCD is temporarily stored in a buffer memory of each color, and then the color separation image information is sequentially stored from the buffer memory. Is read, and a toner image of each color is reproduced on the photoreceptor by the semiconductor laser based on the color separation image information. And
Finally, a color image is reproduced by superimposing toner images of each color on the transfer material surface on the transfer drum.

However, in this method, a single color image is reproduced by superimposing a single color image a plurality of times on the paper supported on the transfer drum, so that it takes time to output one color image. Have the problem of too much.

Therefore, recently, a color recording apparatus of a process in which a plurality of recording units for recording each single color image are arranged in parallel (tandem type) has been considered and commercialized.

In the color recording apparatus of the plurality of processes arranged in parallel, for example, as described in Japanese Patent Application Laid-Open No. 1-142679, photosensitive drums corresponding to each color are arranged in a sheet conveying direction by a transfer conveying belt. And a laser beam scanner unit is arranged in parallel in the transport direction of the transfer transport belt in correspondence with each photosensitive drum.

[0008] This laser beam scanner unit comprises:
The polygon mirror is supported so that it rotates vertically,
A condenser lens and the like are vertically arranged below the polygon mirror in the vertical direction.

[0009]

According to this method, however, the laser beam scanner unit itself disposed above the recording unit (photoreceptor) drum of the process in the apparatus is disposed vertically long, although the speed can be increased. Therefore, the width of the apparatus in the horizontal direction (paper transport direction) is reduced, but the height of the apparatus in the vertical direction (vertical direction) is increased, and the apparatus becomes large.

Accordingly, it is an object of the present invention to provide a color image forming apparatus in which a plurality of laser scanning means are arranged in a state of being partially overlapped with each other to reduce the size of the apparatus.

[0011]

According to another aspect of the present invention, there is provided an image forming apparatus, comprising: an image signal input unit for inputting a color image signal; A plurality of laser scanning units each of which scans a laser beam modulated in accordance with an image signal of each color; and an image recording unit which records a color image corresponding to the image signal of each color by being scanned by the laser scanning unit. Are arranged in parallel, and color images formed in the plurality of recording units arranged in parallel are sequentially transferred onto a transfer material to reproduce a color image. A part of the laser scanning means on the downstream side in the transport direction is arranged in a state of being sequentially superimposed on a part of the laser scanning means on the upstream side in the transport direction, and an image of each color is arranged by the laser scanning means. The image recording sections of the image recording means to be inspected are arranged such that the laser scanning optical path lengths from the corresponding laser scanning means are constant, and the transfer material upstream in the transport direction of the transfer material is positioned below the image recording sections. A transporting means for transporting the transfer material with the downstream side in the transport direction at the upper position is disposed, and a fixing means for fixing an image to the transfer material is disposed downstream of the transporting means in the transport direction of the transfer material. ing.

According to a second aspect of the present invention, in the image forming apparatus, a transfer material reversing path for reversing the front and back of the transfer material to form an image on both surfaces of the transfer material below the transfer means in the direction of conveyance of the transfer material. Has been arranged.

According to a third aspect of the present invention, there is provided an image forming apparatus, wherein image signal input means for inputting a color image signal, and laser light modulated respectively in accordance with the image signal of each color input by the image signal input signal. A plurality of laser scanning means for scanning a plurality of image recording means for recording a color image corresponding to an image signal of each color by being scanned by the laser scanning means. In the one in which a color image is reproduced by sequentially transferring color images formed in a recording unit onto a transfer material, the plurality of laser scanning units are transported to a part of the laser scanning unit on the downstream side in the transport direction of the transfer material. An image recording unit of the image recording unit, in which an image of each color is scanned by each of the laser scanning units, is arranged in a state in which a part of the laser scanning unit on the direction upstream side is sequentially overlapped, The laser scanning optical path lengths from the corresponding laser scanning means are arranged so as to be constant, and the transfer material upstream in the transport direction is located at the upper position, the transport direction downstream is located at the lower position below the image recording unit. A transport unit for transporting the transfer material is disposed, and a sheet feeding unit for feeding the transfer material to the transport unit and a loading unit for loading the transfer material are disposed below the transport unit on the upstream side in the transport direction of the transfer material. doing.

According to a fourth aspect of the present invention, the conveying means of the image forming apparatus is provided so as to be rotatable about its lower side as a center of rotation.

[0015] The apparatus body of the image forming apparatus according to claim 5 is formed so as to be openable above the laser scanning means around the lowermost side of the plurality of laser scanning means, and the laser scanning means is opened when the apparatus body is opened. Sometimes it is arranged to be detachable from the laser scanning means on the upper side.

[0016]

FIG. 1 is a front sectional view showing the configuration of a digital color copying machine 1 which is an image forming apparatus according to an embodiment of the present invention. A document table 11 is provided on the upper surface of the copying machine body 1.
1 and an operation panel.
A document pressing cover (not shown) supported on the document table 111 so as to be openable and closable is mounted on the upper surface of the document table 111. Further, an image reading unit 110 and an image forming unit 210 are configured inside the copying machine main body 1.

First, the image reading unit 110 will be described. In order to read an image of a document A set at a predetermined position on a document table 111 with a document image face down, the document table 1 is read.
A document scanning body that reciprocates in parallel along the lower surface of the document table 111 is disposed below the document table 111.

This original scanning body maintains a constant distance on the lower surface of an original table 111 comprising an exposure lamp for exposing the original image surface and a first mirror for deflecting a reflected light image from the original in a predetermined direction. A first scanning unit 113 that reciprocates in parallel at a predetermined scanning speed, and a second scanning unit 113 that further deflects a reflected light image from a document deflected by a first mirror of the first scanning unit 113 in a predetermined direction. The second scanning unit 1 that reciprocates in parallel with the first scanning unit 113 including the third mirror with a constant speed relationship.
14, an optical lens 115 for reducing a reflected light image from a document deflected by the third mirror of the second scanning unit 114 to form an optical image at a predetermined position, and an optical lens 11
5, a photoelectric conversion element 116 that forms the reduced light image, sequentially photoelectrically converts the light image, and outputs a reflected light image from the document as an electric signal.

The document image information converted into an electric signal by the photoelectric conversion element 116 is further transferred to an image processing unit described later and subjected to predetermined processing as image data.

Next, the image forming section 210 located below the copying machine 1 will be described. Image forming unit 21 shown in FIG.
A paper feed mechanism 211 is provided on the right side of 0, and separates and feeds the sheets P stacked and stored in the sheet tray one by one toward the recording unit side. The paper P separated and supplied one by one is conveyed by controlling the timing by a pair of registration rollers 212 disposed in front of the image forming unit 210, and is resupplied and conveyed at a timing with the image forming unit 210. .

Below the image forming section 210, a transfer / transport belt mechanism 213 extending substantially in parallel is arranged.
The paper P is electrostatically attracted to a transfer / transport belt 216 stretched between a plurality of rollers such as a drive roller 214 and a driven roller 215, and is transported.

Further, a fixing device 217 for fixing the toner image transferred and formed on the sheet P to the sheet P is disposed downstream of the transfer / conveying belt mechanism 213. The fixing device 217 has a fixing roller nip. Is passed through the conveyance direction switching gate 218 and the discharge roller 219.
Paper discharge tray 220 attached to the outer wall of the apparatus
Is discharged on top.

The switching gate 218 selectively switches the transport path of the sheet P to discharge the sheet P after fixing to the outside of the apparatus or to resupply the sheet P to the image forming unit 210 again. The sheet P whose transport direction has been switched again toward the image forming unit 210 by the switching gate 218 is again supplied to the image forming unit after the upside down via the switchback transport path 221.

The driving roller 214 and the driven roller 21
5 and the like, the transfer conveyance belt 216 stretched substantially in parallel.
The first, second, third, and fourth image forming stations Pa, Pb, Pc, and Pd are arranged side by side in the order from the upstream side of the transport path close to the transfer transport belt 216.

The transfer conveyance belt 216 is frictionally driven by the drive roller 214 in the direction indicated by the arrow Z in FIG. 1, and carries the paper P fed through the paper feed mechanism 211 as described above. Are sequentially transported to the above-described image forming stations Pa, Pb, Pc, and Pd.

Each of the image stations Pa, Pb, Pc, and Pd has substantially the same structure, and the photosensitive drums 222a and 222 are driven to rotate in the direction of arrow F shown in FIG.
b, 222c, and 222d, and chargers 223a, 223b, 223c, and 223 that uniformly charge the photosensitive drum 222 around each photosensitive drum 222.
d, developing devices 224a, 224b, 224c and 224d for developing the electrostatic latent images formed on the respective photosensitive drums 222, and transfer dischargers 225a and 225b for transferring the developed toner images to the paper P , 225c, and 2
25d, and cleaning means 226a, 226b, 226 for removing toner remaining on the photosensitive drum 222.
c and 226d are sequentially arranged along the rotation direction of the photosensitive drum 222.

Each photosensitive drum 222a, 222
Above b, 222c, and 222d, a semiconductor laser device that emits dot light modulated according to image data, a deflecting device for deflecting light from the semiconductor laser device in the main scanning direction, and a deflecting device Laser beam scanner units 227a, 227b, 227c, and 227d each including an fθ lens for forming an image of the deflected laser beam on the surface of the photosensitive drum 222 are provided.

The laser beam scanner 227a receives a pixel signal corresponding to the yellow component image of the color original image, the laser beam scanner 227b receives a pixel signal corresponding to the magenta component image of the color original image, and the laser beam scanner 227c receives the color signal. The pixel signal corresponding to the cyan component image of the original image is output to the laser beam scanner 2
A pixel signal corresponding to the black component image of the color original image is input to 27d.

Thus, the photosensitive drum 222 of each recording unit
An electrostatic latent image corresponding to the color-converted original image information is formed on the upper portion, a yellow toner is applied to the developing device 224a of each recording unit, a magenta toner is applied to the developing device 224b, and a developing device 224c is attached to the developing device 224c. Since cyan toner is stored in the developing device 224d and black toner is stored in the developing device 224d, original image information that has been color-converted in each recording unit is reproduced as a toner image of each color.

Further, between the first image forming station Pa and the paper feeding mechanism 211, a paper suction (brush) charger 228 is provided, and the suction charger 228 is provided on the surface of the transfer conveyance belt 216. And the sheet feeding mechanism 211
Is transported from the first image forming station Pa to the fourth image forming station Pd without slipping while the paper P supplied from the printer is securely attracted onto the transport belt 216.

On the other hand, a static eliminator (not shown) is provided almost directly above the drive roller 214 between the fourth image station Pd and the fixing device 217. An alternating current for separating the electrostatically attracted paper P is applied.

In the above-described color copying machine, the paper P
When the sheet P is fed out of a sheet cassette and supplied into a guide of a sheet feeding path of a sheet feeding mechanism 211, the leading end of the sheet P is used as a sensor (not shown). The sheet is temporarily stopped by the registration roller pair 212 according to the detection signal output from the sensor.

The image stations Pa, P
At a timing of b, Pc, and Pd, the sheet is sent to the side of the conveyor belt 216 rotating in the direction of arrow Z in FIG.
At this time, since the conveyor belt 216 is given a predetermined charge by the attraction charger 228 described above, while passing through each of the image stations Pa, Pb, Pc, and Pd,
Stable transport is provided.

In each of the image stations Pa, Pb, Pc, and Pd, a toner image of each color is formed by the above-described configuration, and is superimposed on the supporting surface of the sheet P electrostatically attracted and conveyed by the conveyor belt 216. When the transfer of the image by the fourth image station Pd is completed,
The conveyor belt 21 is discharged from the leading edge of the sheet by the discharger for static elimination.
6 and is guided to the fixing device 217. Then, the sheet P on which the toner image has been finally fixed is discharged onto the sheet discharge tray 220 from the sheet discharge port.

(Circuit Description of Image Processing Unit) Next, the configuration and functions of a color image information image processing unit mounted on a color digital copying machine will be described.

FIG. 2 is a block diagram of the image processing section included in the color digital copying machine 1.

An image processing unit included in the digital copying machine 1 includes an image data input unit 40, an image processing unit 41, an image data output unit 42, a hard disk device or an RA.
An image memory 43 including an M (random access memory), a central processing unit (CPU) 44, and an image editing unit 4
5 and an external interface unit 46.

An image data input unit 40 is a three-line color CCD 40a capable of reading a color original image and outputting line data separated into RGB color components.
A shading correction circuit 40 for correcting the line image level of the line data read by the color CCD 40a
b, a line aligning unit 40c such as a line buffer for correcting a deviation of image line data read by the three-line color CCD 40a, and a three-line color CCD 40a
A sensor color correction section 40d for correcting the color data of the line data of each color output from the MTF correction section 40e for correcting the change of the signal of each pixel so as to have a sharp edge, and a visibility by correcting the brightness of the image. It comprises a gamma correction unit 40f for performing correction.

The image processing unit 41 includes an image data input unit 40
Alternatively, a color space correction circuit 41a that corrects a color reproduction range of a color image signal input via an interface to be described later into a color reproduction range by color toner in the recording apparatus.
A masking circuit 41b for converting the RGB signals of the input image data into YMC signals corresponding to the respective printing units of the printing apparatus; a black signal from the RGB signals of the color image input via the image data input unit 40 or an interface to be described later; An under-color removal / black addition circuit (UCR.) That performs a black addition process of adding a black component signal output from the black detection circuit 41c based on the YMC signal output from the black detection circuit 41c and the masking circuit 41b for detecting components. BP) 41
d, a density processing circuit 41e for adjusting the density of the color image signal based on the density conversion table, a scaling processing circuit 41f for scaling the input image information based on the set magnification, and an image from the input image data. It is composed of a separation / screen circuit 41g for detecting character / photo / halftone dot regions in information to separate regions and determine an image output pattern.

The image data output section 42 performs a pulse width modulation based on the image data of each color by a laser control unit 42a, and performs laser recording based on a pulse width modulation signal corresponding to the image signal of each color outputted from the laser control unit 42a. And laser scanner units 42b, 42c, 42d, 42e for each color.

The image memory 43 sequentially receives the 8-bit 4-color (32-bit) image data output from the image processing section 41 and temporarily stores the 8-bit 4-color (32-bit) image data in the buffer to convert the 32-bit data into 8-bit 4-color image data. A hard disk control unit 43a for converting and outputting the divided data to four hard disks, and for storing and managing image data of 8 bits and 4 colors as image data for each color.
Base hard disks (rotary storage media) 43b, 43c,
43d and 43e.

The central processing unit (CPU) 44 includes an image data input unit 40, an image processing unit 41, an image data output unit 42, an image memory 43, and an image editing unit 4 described later.
5, and controls the external interface unit 46 based on a predetermined sequence.

The image editing unit 45 performs a predetermined image editing on the image data once stored in the image memory 43 via the image data input unit 40, the image processing unit 41, or an interface described later. is there.

The interface 46 is a communication interface means for receiving image data from an external image input processing device provided separately from the digital copying machine 1.

The image data input from the interface 46 is also once input to the image processing unit 41 and subjected to color space correction and the like, to a data level that can be handled by the image recording unit 210 of the digital copying machine 1. The converted data is stored and managed in the hard disks 43b, 43c, 43d, and 43e.

(Explanation of Control Structure of Digital Copier Overall)
FIG. 3 is a diagram showing a state in which the operation of each part of the entire apparatus of the digital copying machine 1 is managed by a central control unit (CPU) 44.

Image data input unit 40, image processing unit 4
1, the image data output unit 42, the image memory 43, and the central processing unit (CPU) 44 are the same as those in FIG.

The central processing unit 44 has the RADF2-
1. Each drive mechanism constituting the digital copier 1 such as a scanner unit and a laser printer unit is managed by sequence control, and a control signal is output to each unit.

Further, an operation board unit 47 comprising an operation panel is connected to the central processing unit 44 in a mutually communicable state, and a control signal is transmitted to the central processing unit 44 in accordance with a copy mode set and inputted by an operator. The digital copying machine 1 is transferred to operate according to the mode.

A control signal indicating the operating state of the digital copier is transferred from the central processing unit 44 to the operation board unit 47, and the operation board unit 47 uses the control signal to determine what state the apparatus is currently in. The operation state is displayed on a display unit or the like as shown to the operator as to whether there is.

Reference numeral 46 denotes image information as described in FIG.
And an image data communication unit provided to enable information communication with other digital image equipment such as image control signals.

(Explanation of Operation Panel) FIG. 4 shows an operation panel in a color digital copying machine.

A touch panel liquid crystal display device 6 is disposed at the center of the operation panel, and various mode setting keys are disposed therearound.

On the screen of the touch panel liquid crystal display device 6, there is a screen switching instruction area for constantly switching to a screen for selecting an image editing function, and by directly pressing this area with a finger, various image editing functions are selected. A list of various editing functions is displayed on the liquid crystal screen so that it can be performed. From among the displayed various editing functions, the operator sets the editing function by touching the area where the desired function is displayed with a finger.

The group of various setting keys arranged on the operation panel will be briefly described. Reference numeral 7 denotes a dial for adjusting the brightness of the screen of the liquid crystal display device 6.

Reference numeral 8 denotes an automatic magnification setting key for setting a mode for automatically selecting a magnification, 9 denotes a zoom key for setting a copy magnification in increments of 1%, and 10 and 11 read and select a fixed magnification. A fixed magnification key 12 is a unity key for returning the copy magnification to a standard magnification (actual magnification).

Reference numeral 13 denotes a density switching key for switching the copy density adjustment from automatic to manual or to the photo mode, 14 denotes a density adjustment key for finely setting the density level in the manual mode or the photo mode, and 15 denotes copying. A tray selection key for selecting a desired paper size of the paper P from paper sizes set in the paper feeding unit of the machine.

Reference numeral 16 denotes a copy number setting key for setting the number of copies, 17 denotes a clear key which is operated when clearing the number of copies or stops continuous copying in the middle, 18 denotes a start key for instructing the start of copying, Reference numeral 19 denotes an all release key for releasing all of the currently set modes and returning to the normal state, reference numeral 20 denotes an interrupt key operated when a copy of another document is desired during continuous copying, and reference numeral 21 denotes a copy machine. An operation guide key for displaying a message about the operation method of the copier by operating it when you do not understand the operation,
Reference numeral 22 denotes a message forward key for displaying a continuation of the message displayed by operating the operation guide key 21. Reference numeral 23 denotes a double-sided mode setting key for setting a double-sided copying mode, and reference numeral 24 denotes a post-processing mode setting key for setting an operation mode of a post-processing apparatus for sorting copies discharged from a copying machine.

Reference numerals 25 to 27 denote setting keys for a printer mode and a facsimile mode. Reference numeral 25 denotes a memory transmission mode key for temporarily storing a transmission original in a memory and then transmitting the same. Reference numeral 26 denotes a copy and fax mode for the digital copying machine. A copy / fax / printer mode switching key 27 for switching between the telephone numbers is a one-touch dial key for storing a destination telephone number in advance and transmitting a telephone call to the destination by one-touch operation during transmission.

The operation panel presented this time and the various keys arranged on the operation panel are merely examples, and the keys provided on the operation panel differ depending on various functions mounted on the color digital copying machine. Needless to say.

(Details of Embodiment of the Present Invention) FIG. 5 is a sectional view of a laser beam scanner unit 227 according to the first embodiment of the present invention. As shown in FIG. Some polygon mirror 61
Is supported by a rotary motor 62 so as to rotate in a substantially horizontal direction, and the polygon mirror 61 deflects a laser beam emitted from a laser light source (not shown) in a substantially horizontal direction.

A first folding mirror 66 is provided, which firstly folds the laser beam deflected in the horizontal direction away from the polygon mirror 61 and passed through the condenser lenses 64 and 65 in the vertical direction by the polygon mirror 61, and the first folding mirror 66 is provided. A second folding mirror 67 that folds the laser light folded by 66 toward the polygon mirror 61 is disposed, and a third folding mirror 68 that emits the laser light folded by the second folding mirror 67 to the photosensitive drum 222 is provided. The laser beam deflected by the polygon mirror 61 is folded by the first, second, and third folding mirrors 66, 67, and 68, and the photosensitive drum 222 is disposed.
Is scanned based on the image input signal.

As shown in FIG. 6, the rotary motor 61
A printer board 60 for controlling the amount of current flowing through the stator coil 601 held on the board 600 and eliminating uneven rotation.
2 are provided. Reference numeral 603 denotes a rotor magnet fixed to the motor rotation shaft 63, and a stator coil 601.
It rotates by the electromagnetic field generated by.

The cylindrical holding portion 604 holds, at its upper end and lower end, a bearing 605 that rotatably supports the rotating shaft 63 such as a ball bearing or a needle bearing. These bearings 605 are assembled with high precision by press-fitting, bonding, or the like so as to maintain horizontality and to keep the rotating shaft 63 of the polygon mirror 61 rotatably supported by the bearings 605 at a right angle. The bearing 605 is not limited to the above, and may be a fluid bearing of air or liquid.

Since the bearing 605 is disposed substantially vertically and holds the polygon mirror 61 substantially horizontally, the abrasion of the rotating shaft 63 due to the influence of the polygon mirror 61 rotating at a high speed (about 35,000 rotations per minute or less). Can be prevented, the life can be extended, the durability is excellent, vibration does not occur even by high-speed rotation, and high image quality can be maintained even during long-term use.

By making the rotor magnet 603 and the stator coil 601 horizontally opposed as described above, the height of the rotary motor 61 can be kept low, and the laser beam scanner unit 227 has the polygon mirror 61 This portion is lower in height than the portion where the first, second and third folding mirrors 66, 67 and 68, which are the laser beam deflecting means, are arranged, and the laser beam scanner unit 227 adjacent to this portion is overlapped and arranged. It is possible to do.

Then, as shown in FIGS. 1 and 7, the laser beam scanner units 227a to 227d for the respective color components first move upstream of the transfer / conveyance belt 216 (paper P).
The laser beam scanner unit 227a is disposed at a position where the laser beam scanner unit 227a is located on the lower side of the laser beam scanner unit 227a. A laser beam scanner unit 227c on the downstream side with respect to the transport direction is arranged so as to partially overlap the low portion of the laser beam scanner unit 227b. As described above, the laser beam scanner units 227a to 227d are sequentially arranged.

The above laser beam scanner unit 227
a to d to the respective photosensitive drums 222a to 222d (the laser beam scanner unit 227).
In order to make the semiconductor laser element, which is the laser light source inside the photoconductor drum 222, the same as that of the photoconductor drum 222,
a to 222d are sequentially arranged obliquely upward.

Then, the photosensitive drums 222a to 222d
The transfer conveyance belt 216 is disposed obliquely with the drive roller 214 side at the lower position and the driven roller 215 side at the upper position.

A transfer device 217 is disposed downstream of the transfer / conveyance belt 216 in the conveyance direction.
A transfer direction switching gate 218 is disposed on the downstream side of the sheet P, and in order to form images on both sides of the sheet P in the lower space on the downstream side (the driven roller 215 side) of the transfer and transfer belt 216, the sheet P is turned over. To form a transport path L1,
A reverse path L2 is formed below the transport path L1.

The transport path L1 includes a transport roller pair 23
0, 231, 232 are provided, and a forward / reverse rotation roller 233 that rotates forward / reversely is provided on the paper entry side of the front / back reverse path L2.

The sheet P conveyed to the conveyance path L1 is conveyed by a pair of conveyance rollers 230, 231, 232, conveyed in the direction of arrow A by a forward / reverse rotation roller 233, and conveyed to a front / back inversion path L2, and then forward / reverse The sheet P conveyed in the reverse path L2 when the roller 233 is rotated in the reverse direction is indicated by an arrow B.
By conveying the sheet P in the opposite direction, the sheet P is turned over, and the sheet P is conveyed to the transfer conveyance belt 216 again, so that an image can be formed on the back surface of the sheet P.

As described above, the transfer conveying belt 21
6 is located above the upstream side, the transfer device 217 located downstream of the transfer / conveying belt 216 is also located in the upper part of the copying machine. Heat is less likely to flow to the other components, and the effect of the heat generated by the transfer device 217 can be minimized.

Further, a path for reversing the front and back of the sheet P can be formed in the lower space on the downstream side of the transfer / transport belt 216, so that the lower space of the transfer / transport belt 216 can be used effectively, and copying can be performed. The machine body can be downsized.

Embodiment 2 of the present invention will be described with reference to FIG. The laser beam scanner unit according to the second embodiment uses a laser beam scanner unit according to the first embodiment that is formed left and right upside down.

First, a laser beam scanner unit 227d is arranged at a position on the downstream side of the transfer / transport belt 216 (paper feed side of the paper P), and the laser beam scanner unit 227d is placed on the lower portion of the laser beam scanner unit 227d in the transport direction. On the other hand, an upstream laser beam scanner unit 227c is disposed so as to partially overlap the laser beam scanner unit 227c, and a laser beam scanner unit 227b on the downstream side in the transport direction is placed on a portion where the height of the laser beam scanner unit 227c is low. Some of them are placed one on top of the other. Thus, the laser beam scanner units 227d to 227a are sequentially arranged.

The above laser beam scanner unit 227
a to d to the respective photosensitive drums 222a to 222d (the laser beam scanner unit 227).
In order to make the semiconductor laser element, which is the laser light source inside the photoconductor drum 222, the same as that of the photoconductor drum 222,
a to 222d are sequentially arranged obliquely upward.

Then, the photosensitive drums 222a to 222d
The transfer conveyance belt 216 is disposed obliquely with the drive roller 214 side at the upper position and the driven roller 215 side at the lower position.

A paper tray 236 for stacking the paper P is disposed in a lower space on the upstream side (on the side of the drive roller 214) of the transfer / transport belt 216, and for feeding the paper P from the paper tray 236 to the transfer / transport belt 216. A paper feed mechanism 211 is provided.

As described above, the transfer conveying belt 21
6 is located higher than the downstream side, a space is created below the upstream side (drive roller 214 side), and the paper tray 236 is placed in the lower space on the upstream side of the transfer conveyance belt 216. Therefore, the space under the transfer / transport belt 216 can be effectively used, and the size of the copying machine can be reduced.

Embodiment 3 of the present invention will be described with reference to FIG. The laser beam scanner unit according to the third embodiment has the same shape as the laser beam scanner unit according to the second embodiment.

First, a laser beam scanner unit 227d is arranged at a position downstream of the transfer / transport belt 216 (on the side of feeding the paper P), and the laser beam scanner unit 227d is placed on a lower portion of the laser beam scanner unit 227d in the transport direction. On the other hand, an upstream laser beam scanner unit 227c is disposed so as to partially overlap the laser beam scanner unit 227c, and a laser beam scanner unit 227b on the downstream side in the transport direction is placed on a portion where the height of the laser beam scanner unit 227c is low. Some of them are placed one on top of the other. Thus, the laser beam scanner units 227d to 227a are sequentially arranged.

The above laser beam scanner unit 227
a to d to the respective photosensitive drums 222a to 222d (the laser beam scanner unit 227).
In order to make the semiconductor laser element, which is the laser light source inside the photoconductor drum 222, the same as that of the photoconductor drum 222,
a to 222d are sequentially arranged obliquely upward.

Then, the photosensitive drums 222a to 222d
The transfer conveyance belt 216 is disposed obliquely with the drive roller 214 side at the upper position and the driven roller 215 side at the lower position.

A paper tray 236 for stacking paper P is disposed in a lower space on the upstream side (on the side of the drive roller 214) of the transfer / transport belt 216, and feeds the paper P from the paper tray 236 to the transfer / transport belt 216. A paper feed mechanism 211 is provided.

The transfer / transport belt 216 is rotatable about the driven roller 215 in the vertical direction as shown by an arrow C on the drive roller 214 side about the driven roller 215 as a rotation axis (not shown) of the driven roller 215. Support.

The transfer / conveying belt 216 is located at a position opposing a position (photosensitive drum 222) shown by a broken line in the drawing operation during copying operation.
When a paper jam of the paper P occurs in the portion d, the transfer conveyance belt 216 is rotated about the driven roller 215 to the position shown by the solid line in FIG. Jammed paper P
Can be easily removed.

Embodiment 4 of the present invention will be described with reference to FIG. The fourth embodiment has the same configuration as that of the third embodiment, and a laser beam scanner unit 227 disposed at the lowermost part of the image reading unit 110 of the copying machine body 1.
A reading unit support shaft 238 is provided on the d side, and a gas spring 239 is provided on the opposite side of the image reading unit 110 on which the reading unit support shaft 238 is provided. The image reading unit 110 can be opened upward by the reaction force of the above.

Then, the laser beam scanner unit 2
At the time of assembling or maintaining the image reading units 27a to 27d, the image reading unit 110 is opened upward from the position indicated by the broken line in the drawing to the position indicated by the solid line around the reading unit support shaft 238 as a rotation center, and the space above the laser beam scanner units 227a to 227d. Open each laser beam scanner unit 2
27a to 27d can be easily assembled and maintained.

[0090]

According to the image forming apparatus of the first aspect, since the downstream side of the transfer means in the transfer material transport direction is located above the upstream side, the downstream side of the transport means is provided. The position of the transfer device also becomes the upper position, so that the heat generated by the transfer device is less likely to flow to the other components, and the influence of the heat generated by the transfer device on other components can be minimized.

According to the image forming apparatus of the present invention, a transfer material reversing path for reversing the front and back of the transfer material can be formed in a lower space on the downstream side of the transfer means in the transfer material conveyance direction. The space can be used effectively, and the size of the image forming apparatus can be reduced.

According to the image forming apparatus of the third aspect, the downstream side of the transfer means in the transfer material transport direction is located at a position higher than the upstream side. A paper feeding means for feeding the transfer material to the transport means and a stacking portion for stacking the transfer material can be arranged in the space, so that the space in the image forming apparatus can be effectively used, and the image forming apparatus can be reduced in size. Can be

According to the image forming apparatus of the fourth aspect, since the transporting means is rotatably provided about the lower position side thereof by utilizing the space below the transporting means, the transfer material is provided in the image recording unit. Even if clogging occurs, the lower part of the image recording section can be largely opened, the transfer material can be easily removed, and there is no need to provide a dedicated space for removing the transfer material. Space can be used effectively.

According to the image forming apparatus of the fifth aspect, since the apparatus main body is formed to be openable above the laser scanning means, it is possible to largely open the upper part of the laser scanning means at the time of assembling the laser scanning means or performing maintenance. Thus, assembly and maintenance of the laser scanning means can be easily performed.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a digital color copying machine which is an image forming apparatus of the present invention.

FIG. 2 is a block diagram of an image processing unit of a digital color copying machine which is an image forming apparatus of the present invention.

FIG. 3 is a control configuration diagram of a digital color copying machine which is an image forming apparatus of the present invention.

FIG. 4 is a plan view showing an operation panel of the digital color copying machine which is the image forming apparatus of the present invention.

FIG. 5 is a sectional view of a main part of a first embodiment of a digital color copying machine which is an image forming apparatus of the present invention.

FIG. 6 is a sectional view of the rotary motor of FIG. 5;

FIG. 7 is a sectional view of Embodiment 1 of the digital color copying machine which is the image forming apparatus of the present invention.

FIG. 8 is a cross-sectional view of Embodiment 2 of a digital color copying machine that is an image forming apparatus of the present invention.

FIG. 9 is a cross-sectional view of Embodiment 3 of a digital color copying machine which is an image forming apparatus of the present invention.

FIG. 10 is a cross-sectional view of Embodiment 4 of a digital color copying machine that is an image forming apparatus of the present invention.

[Explanation of symbols]

 216 Transfer / transport belt 222a-d Photoconductor drum 227a-d Laser beam scanner unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shoichiro Yoshiura 22-22, Nagaikecho, Abeno-ku, Osaka City, Osaka Inside (72) Inventor Osamu Fujimoto 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Inside the corporation

Claims (5)

[Claims] 1. An image signal input means for inputting a color image signal, and a plurality of laser scanning means for scanning laser light modulated respectively in accordance with image signals of respective colors input by the image signal input signal. And a plurality of image recording means for recording a color image corresponding to an image signal of each color by being scanned by the laser scanning means, and a color image formed in each of the plurality of recording units arranged in parallel. Are sequentially transferred onto a transfer material to reproduce a color image, wherein the plurality of laser scanning units are arranged such that a part of the laser scanning unit on the upstream side in the transport direction of the transfer material is laser-scanned on the downstream side in the transport direction. The image recording units of the image recording unit, in which the laser scanning units scan the images of the respective colors, are arranged in such a manner that a part of the units are sequentially superimposed, The length of the laser scanning optical path from the inspection means is set to be constant, and the transfer material is positioned below the image recording unit, with the upstream side in the transport direction of the transfer material at the lower position, and the downstream side in the transport direction at the upper position, respectively. An image forming apparatus comprising: a conveying unit that conveys an image; and a fixing unit that fixes an image on the transfer material, disposed downstream of the conveying unit in the conveying direction of the transfer material. 2. A transfer material reversing path for reversing the front and back of a transfer material in order to form an image on both surfaces of the transfer material is disposed below the transfer means on the downstream side in the transfer material transport direction. The image forming apparatus according to claim 1. 3. An image signal input means for inputting a color image signal, and a plurality of laser scanning means for scanning laser light modulated in accordance with image signals of respective colors input by the image signal input signal. And a plurality of image recording means for recording a color image corresponding to an image signal of each color by being scanned by the laser scanning means, and a color image formed in each of the plurality of recording units arranged in parallel. Are sequentially transferred onto a transfer material to reproduce a color image, wherein the plurality of laser scanning units are arranged such that a part of the laser scanning unit on the downstream side in the transport direction of the transfer material is scanned with the laser on the upstream side in the transport direction. The image recording units of the image recording unit, in which the laser scanning units scan the images of the respective colors, are arranged in such a manner that a part of the units are sequentially superimposed, The length of the laser scanning optical path from the inspection means is set to be constant, and the transfer material is positioned below the image recording section, with the upstream side in the transport direction of the transfer material at the upper position, and the downstream side in the transport direction at the lower position, respectively. Transport means for transporting the transfer material, and a sheet feeding means for feeding the transfer material to the transport means and a loading unit for loading the transfer material are arranged below the transport means on the upstream side in the transport direction of the transfer material. Image forming apparatus. 4. The apparatus according to claim 1, wherein the transport means is rotatably provided around a lower side thereof as a center of rotation.
Alternatively, the image forming apparatus according to claim 3. 5. An apparatus main body is formed so as to be openable above said laser scanning means with a center on a lowermost side of said plurality of laser scanning means, said laser scanning means being an upper laser scanning means when said apparatus main body is opened. The image forming apparatus according to claim 1, wherein the image forming apparatus is detachably disposed.