JP3374057B2 - Image forming device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image signal inputting means for inputting a color image signal, and a laser beam which is respectively modulated according to the image signal of each color inputted 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 are arranged in parallel, and the plurality of recording portions arranged in parallel. The present invention relates to an image forming apparatus that reproduces a color image by sequentially transferring color images formed on the transfer material.

[0002]

2. Description of the Related Art In a color image forming apparatus, for example, a color digital copying machine, a printer unit outputs a color original after performing a predetermined image processing on the image of the original input from a scanner.

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

Looking at the color image forming apparatus described in this publication, the color separated image of the color original read by the color CCD is once stored in the buffer memory for each color, and then the color separated image information is sequentially stored from the buffer memory. Is read out, and the toner image of each color is reproduced on the photoconductor by the semiconductor laser based on the color separated image information. And
Finally, a color image is reproduced by superimposing the toner images of the respective colors on the surface of the transfer material on the transfer drum.

However, according to this method, since a color image is reproduced by superposing a single color image on the paper supported on the transfer drum a plurality of times, it takes time to output one color image. I have a problem that is too much.

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

In the color recording apparatus of the process of arranging a plurality of them in parallel, for example, as described in JP-A-1-142679, photosensitive drums corresponding to respective colors are arranged in a sheet conveying direction by a transfer / conveying belt. The laser beam scanner units are arranged in parallel in the transport direction of the transfer transport belt so as to correspond to the respective photosensitive drums.

This laser beam scanner unit is
The polygon mirror is pivotally supported to rotate in the vertical direction,
A condenser lens or the like was vertically arranged vertically below the polygon mirror.

[0009]

However, with this method, although the speed can be increased, the laser beam scanner unit itself, which is arranged above the recording section (photoreceptor) drum of the process in the apparatus, is arranged long in the vertical direction. As a result, 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.

Therefore, it is an object of the present invention to provide a color image forming apparatus in which the size of the apparatus is reduced by arranging a part of the plurality of laser scanning means in a superposed state.

[0011]

In order to achieve the above object, an image forming apparatus according to claim 1 is provided with an image signal input means for inputting a color image signal and each color input by the image signal input signal. A plurality of laser scanning means for scanning the laser light each modulated according to the image signal of, and an image recording means for recording a color image according to the image signal of each color by being scanned by the laser scanning means. In the image forming apparatus which reproduces a color image by arranging a plurality of them in parallel and sequentially transferring the color images formed in each of the plurality of recording units arranged in parallel onto a transfer material, the plurality of laser scanning means are are arranged with a portion sequentially superposed with the laser scanning unit in the conveying direction upstream side to a part of the laser scanning means on the downstream side in the transport direction of the wood, by the respective laser scanning unit of each color Image recording portion of the image recording means the image is scanned, arranged so that the laser scanning optical path length from the respective corresponding laser scanning means is constant, the upstream side of the transfer material below the image recording unit A transport unit for transporting the transfer material is disposed at the upper position, with the downstream side in the transport direction at the lower position, and the transport unit upstream of the transport unit in the transport direction.
And a paper feeding means for feeding the transfer material to the conveying means below
And a loading section for loading the transfer material, and
It was rotatably provided with its lower side as the center of rotation.
Is characterized by.

[0012]

[0013]

[0014]

The apparatus main body of the image forming apparatus according to claim 2 is formed so as to be opened above the laser scanning means around the lowermost side of the plurality of laser scanning means, and the laser scanning means opens the main body of the apparatus. It is sometimes arranged to be detachable from the laser scanning means on the upper side.

[0016]

1 is a front sectional view showing the structure of a digital color copying machine 1 which is an image forming apparatus according to an embodiment of the present invention. On the upper surface of the copying machine body 1, a document table 11
1 and an operation panel are provided, and a document table 11 is provided.
A document pressing cover (not shown) supported in an openable and closable state with respect to the document table 111 is mounted on the upper surface of the document 1. 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 section 110 will be described. In order to read the image of the document A set with the document image surface downward at a predetermined position on the document table 111, the document table 1 is read.
A document scanning body that reciprocates in parallel along the lower surface of the document table 111 is arranged below the document table 11.

The original scanning body maintains a constant distance on the lower surface of the original table 111, which comprises an exposure lamp for exposing the original image surface and a first mirror for deflecting the 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 toward a predetermined direction. The second scanning unit 1 which reciprocates in parallel with the first scanning unit 113 composed of the third mirror in a constant speed relationship.
14, an optical lens 115 for reducing the reflected light image from the 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
An optical image reduced by 5 is formed, and a photoelectric conversion element 116 that sequentially photoelectrically converts the optical image and outputs the reflected light image from the document as an electric signal is formed.

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

Next, the image forming section 210 located on the lower side of 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 the papers P stacked and accommodated in the paper tray are separated one by one and supplied toward the recording unit side. The sheets P separated and supplied one by one are conveyed by controlling the timing by the registration roller pair 212 arranged in front of the image forming section 210, and are re-supplied and conveyed by the image forming section 210 in time. .

Below the image forming section 210, a transfer / conveying belt mechanism 213 extending substantially in parallel is arranged.
The sheet P is electrostatically adsorbed and conveyed by a transfer conveyance belt 216 stretched between a plurality of rollers such as a driving roller 214 and a driven roller 215.

Further, a fixing device 217 for fixing the toner image transferred and formed on the paper P on the paper P is disposed on the downstream side of the transfer / conveying belt mechanism 213, and between the fixing roller nips of the fixing device 217. After passing through the sheet, the sheet passes through the conveyance direction switching gate 218 and the discharge roller 219.
Output tray 220 attached to the outer wall of the apparatus by
Discharged on top.

The switching gate 218 selectively switches the transport path of the sheet P, whether the sheet P after fixing is discharged to the outside of the apparatus or is re-supplied toward the image forming section 210. The paper P whose conveyance direction has been switched again toward the image forming unit 210 by the switching gate 218 is supplied again to the image forming unit after being turned upside down via the switchback conveyance path 221.

Further, the driving roller 214 and the driven roller 21
Transfer conveyance belt 216 stretched substantially in parallel with the like
First, second, third, and fourth image forming stations Pa, Pb, Pc, and Pd are juxtaposed on the upper side of the transfer conveyance belt 216 in order from the upstream side of the conveyance path.

The transfer / conveying belt 216 is frictionally driven by the driving roller 214 in the direction indicated by the arrow Z in FIG. 1, and carries the sheet P fed through the sheet feeding mechanism 211 as described above. Then, the image forming stations Pa, Pb, Pc, and Pd are sequentially conveyed.

The image stations Pa, Pb, Pc, and Pd have 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 around each photosensitive drum 222, chargers 223a, 223b, 223c, and 223 that uniformly charge the photosensitive drum 222.
d, developing devices 224a, 224b, 224c, and 224d that develop the electrostatic latent image formed on each photoconductor drum 222, and transfer dischargers 225a and 225b that transfer the developed toner image to the paper P. , 225c, and 2
25d and cleaning means 226a, 226b, 226 for removing the toner remaining on the photosensitive drum 222.
c and 226d are sequentially arranged along the rotation direction of the photoconductor drum 222.

Further, the photosensitive drums 222a, 222
Above b, 222c, and 222d, a semiconductor laser element that emits dot light modulated according to image data, a deflecting device for deflecting the light from the semiconductor laser element in the main scanning direction, and a deflecting device are provided. Laser beam scanner units 227a, 227b, 227c, and 227d each including an fθ lens for forming an image of the deflected laser light 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. Pixel signals corresponding to the cyan component image of the original image, and the laser beam scanner 2
Pixel signals corresponding to the black component image of the color original image are input to 27d.

As a result, the photosensitive drum 222 of each recording unit is
An electrostatic latent image corresponding to the color-converted original image information is formed on the developing device 224a of each recording unit, yellow toner, developing device 224b magenta toner, and developing device 224c. Since cyan toner and black toner are stored in the developing device 224d, the original image information color-converted in each recording unit is reproduced as a toner image of each color.

Further, a sheet suction (brush) charger 228 is provided between the first image forming station Pa and the sheet feeding mechanism 211, and this suction charger 228 is the surface of the transfer / transport belt 216. To charge the paper feeding mechanism 211
The sheet P supplied from the first image forming station Pa is conveyed to the fourth image forming station Pd without being displaced in a state where the sheet P is surely adsorbed on the conveyor belt 216.

On the other hand, between the fourth image station Pd and the fixing device 217, a static eliminator (not shown) is provided almost directly above the drive roller 214, and the static eliminator is provided on the conveyor belt 216. An alternating current is applied to separate the electrostatically attracted paper P.

In the color copying machine having the above structure, the paper P
A sheet of cut sheet is used as the sheet P, and when the sheet P is sent out from the sheet feeding cassette and fed into the guide of the sheet feeding / conveying path of the sheet feeding mechanism 211, the tip portion of the sheet P is detected by a sensor (not shown). The sheet is once stopped by the registration roller pair 212 by a detection signal output from this sensor.

Then, the respective image stations Pa, P
It is sent to the side of the conveyor belt 216 rotating in the direction of arrow Z in FIG. 1 with the timing of b, Pc, and Pd.
At this time, since the conveyor belt 216 is given a predetermined charge by the attraction charger 228 described above, while passing through the image stations Pa, Pb, Pc, and Pd,
It will be stably conveyed and supplied.

At each of the image stations Pa, Pb, Pc, and Pd, a toner image of each color is formed by the above-described structure, and is superposed on the support surface of the paper P electrostatically 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 driven from the leading edge of the sheet by a discharger for discharging electricity.
6 is peeled off from above and guided to the fixing device 217. Then, the paper P on which the toner image is finally fixed is discharged from the paper discharge port onto the paper discharge tray 220.

(Explanation of Circuit of Image Processing Unit) Next, the structure and function of the image processing unit of the color image information installed in the color digital copying machine will be explained.

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

The 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 RA.
An image memory 43 including M (random access memory) and the like, a central processing unit (CPU) 44, an image editing unit 4
5 and an external interface unit 46.

The image data input section 40 is a 3-line color CCD 40a capable of outputting line data obtained by reading a color original image and performing color separation into RGB color components.
Shading correction circuit 40 for correcting the line image level of the line data read by the color CCD 40a
b, a line matching unit 40c such as a line buffer for correcting a deviation of image line data read by the 3-line color CCD 40a, and a 3-line color CCD 40a
The sensor color correction unit 40d that corrects the color data of the line data of each color output from the device, the MTF correction unit 40e that corrects the change in the signal of each pixel so that the change of the signal of each pixel, the visibility by correcting the brightness of the image It is composed of a γ correction unit 40f for performing the correction.

The image processing section 41 includes an image data input section 40.
Alternatively, a color space correction circuit 41a that corrects the color gamut of a color image signal input via an interface described later to the color gamut of color toner in the recording device,
And a masking circuit 41b for converting the RGB signal of the input image data into a YMC signal corresponding to each recording unit of the recording apparatus, the RGB signal of the color image input through the image data input unit 40 or an interface described later to black. An undercolor removal / black addition circuit (UCR) for performing black addition processing for adding the black component signal output from the black detection circuit 41c based on the YMC signal output from the black detection circuit 41c that detects the component and the masking circuit 41b. BP) 41
d, a density processing circuit 41e that adjusts the density of the color image signal based on the density conversion table, a scaling processing circuit 41f that scales the input image information based on the set scaling ratio, and an image from the input image data. It is composed of a separation / screen circuit 41g for detecting character / photo / halftone areas in the information and separating the areas and determining an image output pattern.

The image data output unit 42 performs laser recording based on a pulse width modulation signal corresponding to the image signal of each color output from the laser control unit 42a and the laser control unit 42a which performs pulse width modulation based on the image data of each color. It is composed of laser scanner units 42b, 42c, 42d and 42e of respective colors for performing.

The image memory 43 sequentially receives 8-bit 4-color (32-bit) image data output from the image processing unit 41, and temporarily stores the 8-bit 4-color (32-bit) image data into 8-bit 4-color image data while temporarily storing it in a buffer. A hard disk control unit 43a that outputs the converted data for division management into four hard disks, and stores and manages 8-bit 4-color image data as image data for each color.
Base hard disks (rotating storage media) 43b, 43c,
It consists of 43d and 43e.

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

The image editing unit 45 is for performing a predetermined image editing on the image data temporarily 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.

Further, 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 input to the image processing unit 41 and subjected to color space correction or 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, 43e.

(Explanation of control structure of the entire digital copying machine)
FIG. 3 is a diagram showing a state in which each unit of the entire apparatus of the digital copying machine 1 is operation-managed by a central control unit (CPU) 44.

Image data input section 40, image processing section 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 is RADF2-
1, the scanner unit, the laser printer unit, and the like, each drive mechanism unit that configures the digital copying machine 1 is managed by sequence control, and a control signal is output to each unit.

Further, an operation board unit 47 composed of an operation panel is connected to the central processing unit 44 in a mutually communicable state, and a control signal is sent to the central processing unit 44 according to the copy mode set and input by the operator. The data is transferred and the digital copying machine 1 is operated according to the mode.

Further, a control signal indicating the operation state of the digital copying machine is transferred from the central processing unit 44 to the operation board unit 47, and the operation board unit 47 side uses the control signal to determine the current state of the apparatus. Whether or not there is an operation state is displayed on the display unit or the like as shown to the operator.

Reference numeral 46 is image information as described in FIG.
And an image data communication unit provided for enabling information communication with other digital image devices such as image control signals.

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

A touch panel liquid crystal display device 6 is arranged in the central portion of the operation panel, and various mode setting key groups are arranged around the touch panel liquid crystal display device 6.

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. When this area is directly pressed with a finger, various image editing functions are selected. A list of various editing functions is displayed on the LCD screen so that you can do it. The editing function is set by touching the area, in which the function desired by the operator is displayed, with a finger from the various editing functions displayed.

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

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

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

Reference numeral 16 is a number setting key for setting the number of copies, 17 is a clear key which is operated to clear the number of copies or to stop the continuous copying on the way, and 18 is a start key for instructing the start of copying. Reference numeral 19 is an all release key for releasing all of the currently set modes to return to the standard state, 20 is an interrupt key which is operated when it is desired to copy another document during continuous copying, and 21 is a copy machine. Operation guide key for displaying a message on the operation method of the copying machine by operating when you do not know the operation,
Reference numeral 22 is a message sequential key for displaying the continuation of the message displayed by operating the operation guide key 21. Reference numeral 23 is a double-sided mode setting key for setting the double-sided copying mode, and 24 is a post-processing mode setting key for setting the operation mode of the post-processing device for sorting the copies discharged from the copying machine.

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

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

(Details of Embodiments 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. 5, the laser beam scanner unit 227 includes a deflector. A polygon mirror 61
The rotation shaft 63 of the polygon mirror 61 is supported by a rotation motor 62 so as to rotate in a substantially horizontal direction, and the polygon mirror 61 deflects the laser light emitted from a laser light source (not shown) in a substantially horizontal direction.

The first folding mirror 66 is arranged to first fold back the laser light deflected in the horizontal direction away from the polygon mirror 61 by the polygon mirror 61 and passing through the condenser lenses 64 and 65 in the vertical direction. A second folding mirror 67 is provided for returning the laser light reflected by 66 to the polygon mirror 61 side, and a third folding mirror 68 for emitting the laser light returned by the second folding mirror 67 to the photosensitive drum 222 is provided. The laser beam deflected by the polygon mirror 61 is folded back by the first, second, and third folding mirrors 66, 67, 68, and the photosensitive drum 222 is arranged.
Are scanned based on the image input signal.

The rotary motor 61, as shown in FIG.
Printer board 60 for controlling the amount of current flowing through the stator coil 601 held on the board 600 to eliminate uneven rotation
Two are provided. A rotor magnet 603 is fixed to the motor rotating shaft 63 and includes a stator coil 601.
It is rotated by the electromagnetic field generated by.

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

Since the bearing 605 is arranged substantially vertically and holds the polygon mirror 61 substantially horizontally, the rotating shaft 63 is deviated 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 at high speed rotation, and high image quality can be maintained even in long-term use.

As described above, by making the rotor magnet 603 and the stator coil 601 face each other horizontally, the height of the rotary motor 61 can be suppressed to a low level, and the laser beam scanner unit 227 has the polygon mirror 61 arranged. The height is lower 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 becomes possible to do.

The laser beam scanner units 227a to 227d for the respective color components are, as shown in FIGS. 1 and 7, first of all, on the upstream side of the transfer / conveying belt 216 (paper P.
The laser beam scanner unit 227a is arranged at a position on the sheet feeding side), and the laser beam scanner unit 227b on the downstream side with respect to the transport direction partially occupies a portion of the laser beam scanner unit 227a having a low height. The laser beam scanner unit 227c is arranged so as to be superposed on the low-height portion of the laser beam scanner unit 227b, and a part of the laser beam scanner unit 227c on the downstream side in the transport direction is superposed. In this way, the laser beam scanner units 227a to 227d are sequentially arranged.

The laser beam scanner unit 227
Laser scanning optical path length from a to d to each of the photosensitive drums 222a to 222d (laser beam scanner unit 227)
In order to make the semiconductor laser element, which is the laser light source inside, and the photosensitive drum 222) the same,
a to 222d are sequentially arranged diagonally upward.

Then, the photosensitive drums 222a to 222d
The transfer / conveying belt 216 is obliquely disposed below the drive roller 214 side in the lower position and the driven roller 215 side in the upper position.

A transfer device 217 is arranged on the downstream side of the transfer / transport belt 216 in the transport direction.
A transfer direction switching gate 218 is disposed on the downstream side of the sheet P to reverse the front and back sides of the sheet P 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 / transport belt 216. To form a transport path L1 of
A front / back reversal path L2 is formed below the transport path L1.

A pair of transport rollers 23 is provided on the transport path L1.
0, 231, 232 are provided, and a forward / reverse rotation roller 233 that rotates forward / reversely is provided on the sheet entrance side of the front / back inversion path L2.

The sheet P transported to the transport path L1 is transported by the transport roller pair 230, 231, 232, transported in the direction of arrow A by the forward / reverse rotation roller 233 and transported to the front / back inversion path L2, and then forward / reverse rotation. The paper P conveyed in the front / back reversing path L2 by the reverse rotation of the roller 233 is indicated by an arrow B.
By conveying the sheet P in the opposite direction, the front and back sides of the sheet P are reversed, and the sheet P is conveyed again to the transfer / conveying belt 216 so that an image can be formed on the back side of the sheet P.

As in the above structure, the transfer / transport belt 21
Since the downstream side of 6 is disposed above the upstream side, the position of the transfer device 217 disposed downstream of the transfer / conveying belt 216 is also the upper part in the copying machine, and therefore occurs in the transfer device 217. It becomes difficult for heat to flow to the side of other components, and the influence of heat generated by the transfer device 217 can be suppressed as much as possible.

Further, a path for reversing the front and back of the paper 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 effectively used, and copying can be performed. The machine body can be downsized.

The second embodiment 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 which is formed by reversing the left and right sides of the laser beam scanner unit according to the first embodiment.

First, the laser beam scanner unit 227d is arranged at a position on the downstream side of the transfer / conveyance belt 216 (paper feed side of the sheet P), and the laser beam scanner unit 227d is arranged on the low-height portion in the conveyance direction. On the other hand, the laser beam scanner unit 227c on the upstream side is arranged so as to overlap a part thereof, and the laser beam scanner unit 227b on the downstream side with respect to the transport direction is provided on the low-height portion of the laser beam scanner unit 227c. Part of them are placed on top of each other. In this way, the laser beam scanner units 227d to 227a are sequentially arranged.

The laser beam scanner unit 227
Laser scanning optical path length from a to d to each of the photosensitive drums 222a to 222d (laser beam scanner unit 227)
In order to make the semiconductor laser element, which is the laser light source inside, and the photosensitive drum 222) the same,
a to 222d are sequentially arranged diagonally upward.

Then, the photosensitive drums 222a to 222d
The transfer / conveying belt 216 is obliquely disposed below the drive roller 214 side in the upper position and the driven roller 215 side in the lower position.

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

As in the above configuration, the transfer / transport belt 21
Since the upstream side of 6 is disposed above the downstream side, a space is created in the lower portion of the upstream side (drive roller 214 side), and the paper tray 236 is placed in the lower space of the upstream side of the transfer / conveying belt 216. In this case, the lower space of the transfer / transport belt 216 can be effectively used, and the main body of the copying machine can be downsized.

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

First, the laser beam scanner unit 227d is arranged at a position on the downstream side of the transfer / conveyance belt 216 (paper feed side of the paper P), and the laser beam scanner unit 227d is arranged on the lower portion of the laser beam scanner unit 227d in the conveyance direction. On the other hand, the laser beam scanner unit 227c on the upstream side is arranged so as to overlap a part thereof, and the laser beam scanner unit 227b on the downstream side with respect to the transport direction is provided on the low-height portion of the laser beam scanner unit 227c. Part of them are placed on top of each other. In this way, the laser beam scanner units 227d to 227a are sequentially arranged.

The laser beam scanner unit 227
Laser scanning optical path length from a to d to each of the photosensitive drums 222a to 222d (laser beam scanner unit 227)
In order to make the semiconductor laser element, which is the laser light source inside, and the photosensitive drum 222) the same,
a to 222d are sequentially arranged diagonally upward.

Then, the photosensitive drums 222a to 222d
The transfer / conveying belt 216 is obliquely disposed below the drive roller 214 side in the upper position and the driven roller 215 side in the lower position.

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

The transfer / conveying belt 216 is rotatable about the driven roller 215 as a center of rotation on the drive roller 214 side in the vertical direction as shown by an arrow C by a rotation shaft (not shown) of the driven roller 215. I support you.

The transfer / conveying belt 216 is located at a position facing the position (photosensitive drum 222) indicated by the broken line in the drawing during the copying operation.
When a paper jam of the paper P occurs at the portion d, the transfer / transport belt 216 is rotated about the driven roller 215 to the position shown by the solid line in the figure, so that the paper jam processable space of the paper P is greatly opened. Paper P that is jammed
Can be easily removed.

The fourth embodiment 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 arranged at the bottom of the image reading unit 110 of the copying machine body 1.
The reading unit support shaft 238 is provided on the d side, and the gas spring 239 is provided on the opposite side of the image reading unit 110 where the reading unit support shaft 238 is provided. The gas spring 239 is provided around the reading unit support shaft 238 as a rotation center. The image reading unit 110 can be opened upward by the reaction force of.

Then, the laser beam scanner unit 2
At the time of assembling and maintenance of 27a to 27d, the image reading unit 110 is opened upward from the position shown by the broken line in the figure to the position shown by the solid line with the reading unit support shaft 238 as the rotation center, and the space above the laser beam scanner units 227a to 227d is opened. Open each laser beam scanner unit 2
27a to 27d are 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 transfer direction is located above the upstream side, the transfer material transfer method of the transfer means.
The transfer means feeds the transfer material into the space below the improvement stream.
It is possible to arrange a stacking unit that stacks a sheet feeding unit and a transfer material.
It is possible to effectively use the space inside the image forming apparatus.
Therefore, the image forming apparatus can be downsized.

[0091]

[0092]

[0093] Further, since the rotatably provided as the pivot center to its lower position side conveying means by utilizing the space below the conveying means, even if the transfer material jam occurs in the image recording unit,
The lower part of the image recording unit can be largely opened, the transfer material can be easily removed, and it is not necessary to provide a dedicated space for removing the transfer material, and the space in the image forming apparatus can be effectively used. be able to.

According to the image forming apparatus of the second aspect , since the main body of the apparatus is formed so as to be opened above the laser scanning means, the upper side of the laser scanning means can be largely opened at the time of assembling or maintenance of the laser scanning means. Therefore, it is possible to easily assemble and maintain the laser scanning means.

[Brief description of 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 configuration 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 that is an image forming apparatus of the present invention.

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

FIG. 5 is a cross-sectional view of essential parts of a first embodiment of a digital color copying machine that is an image forming apparatus of the present invention.

6 is a cross-sectional view of the rotary motor of FIG.

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

FIG. 8 is a sectional view of a second embodiment of a digital color copying machine that is an image forming apparatus of the present invention.

FIG. 9 is a sectional view of a third embodiment of a digital color copying machine that is an image forming apparatus of the present invention.

FIG. 10 is a sectional view of a fourth embodiment of a digital color copying machine that is an image forming apparatus of the present invention.

[Explanation of symbols]

216 Transfer conveyor belt 222a-d photoconductor drum 227a-d laser beam scanner unit

─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Shoichiro Yoshiura 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Inventor Osamu Fujimoto 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Sharp Corporation (56) Reference JP-A-8-190245 (JP, A) JP-A-9-114172 (JP, A) JP-A-9-197756 (JP, A) JP-A-9-251223 (JP, A) JP-A-8-87151 (JP, A) JP-A-8-328395 (JP, A) JP-A-9-218551 (JP, A) JP-A-5-241457 (JP, A) JP-A-7-98547 (JP, A) JP-A-4-314074 (JP, A) JP-A-6-19270 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 15/01-15 / 01 117 G03G 15/16 G03G 15/04-15/04 120 G03G 15/00 550

Claims (2)

(57) [Claims] 1. An image signal inputting means for inputting a color image signal, and a plurality of laser scanning means for scanning laser light, each of which is modulated in accordance with the image signal of each color inputted 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 are arranged in parallel, and a color image formed in each of the plurality of recording sections arranged in parallel. In the image forming apparatus that reproduces a color image by sequentially transferring the images onto a transfer material, the plurality of laser scanning means are provided in a part of the laser scanning means on the downstream side in the transfer material transport direction and upstream in the transport direction. The image recording units of the image recording units, which are arranged in such a manner that a part of the laser scanning units on the side are sequentially overlapped, and the images of the respective colors are scanned by the respective laser scanning units, respectively correspond to the corresponding lasers. The laser scanning optical path length from the scanning means is arranged to be constant, the upstream side in the transport direction of the transfer material is in the upward direction below the image recording unit, and the downstream side in the transport direction is in the lower position. Conveying means for arranging each of them to convey the transfer material is arranged, and the conveying means is arranged below the conveying means on the upstream side in the conveying direction of the transfer material.
Paper feeding means for feeding the transfer material to the means and stacking the transfer material
The loading section is arranged, and the transport means is rotatable about the lower side as a rotation center.
An image forming apparatus characterized by being provided in . 2. An apparatus main body is provided with the plurality of laser scanning means.
Can be opened above the laser scanning means centering on the bottom side
The laser scanning means is configured to open the main body of the device.
The image forming apparatus according to claim 1, wherein the image forming apparatus is arranged so as to be attachable to and detachable from the laser scanning unit on the upper side at times .