JP2764322B2 - Color image forming equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image forming apparatus such as a color printer or a color copying machine in which an exposed surface of an image forming body is protected by a shutter member.

[Conventional technology]

Conventionally, many proposals have been made on techniques for protecting the exposed surface of an image forming body. For example, there are JP-A-59-34546, JP-A-59-61865 and JP-A-59-61860. Each of the techniques described in these publications is an apparatus for forming a monochrome image, and the protection of the exposed surface of the image forming body is performed by opening the above-mentioned housing provided to be openable to the apparatus main body, or by opening the image. This is performed by opening and closing a shutter member that operates in conjunction with insertion and removal of a unit including a forming unit.

[Problems to be solved by the invention]

However, in the case of the color image forming apparatus, the structure and control of the apparatus are complicated, and the frequency of jam processing and component replacement is increased. A malfunction occurs in the interlocking operation with the insertion / removal of the unit, and the opening and closing of the upper housing and the insertion / removal of the unit are performed without the exposed surface of the image forming body being blocked.As a result, the image forming body is damaged and deteriorated early. However, there is a problem that a good image cannot be obtained.

Further, as a color image forming apparatus using an image forming drum, for example, JP-A-1-76076 and JP-A-1-112
268 and JP-A-1-112269. In these color image forming apparatuses, a plurality of rotations of the image forming drum form a color toner image formed by superimposing each color toner image on the drum, and collectively transfer and fix the color toner image on a transfer material to fix the color image. Is formed. According to this image forming apparatus, there is an advantage that the superposition accuracy of each color toner image is high and a color image with high resolution is obtained, but no protection measures are taken for the exposed surface of the image forming body.

In addition, a color image forming apparatus using an image forming belt is known from, for example, EX-7500 in a sharp full-color copying machine, but also in this apparatus, no protection measures are taken for the exposed surface of the image forming body.

(Object of the Invention) The present invention has been proposed in view of the above-mentioned circumstances,
The upper housing is opened to the main body of the apparatus, and the surface of the image forming body exposed when the unit including the image forming means is inserted / removed is always protected without malfunction, and the color having excellent resolution is always provided. An object of the present invention is to provide a color image forming apparatus capable of constantly supplying an image.

[Structure and operation of the invention]

The object is to provide an image forming unit including at least an image forming body, a plurality of developing devices provided on a peripheral edge of the image forming body, a cleaning device, and an exposure device, and a paper feed cassette below the image forming body. In the color image forming apparatus, the image forming body is provided with a shutter member for protecting an exposed surface of the image forming body, and the shutter member interlocks with insertion and removal of the sheet cassette. This is achieved by a color image forming apparatus characterized by being opened and closed.

In the color image forming apparatus of the present invention, the image forming body to be incorporated may be either a photosensitive drum or a photosensitive belt, and a charger provided on a peripheral edge thereof, a plurality of developing devices,
An image forming unit is integrated with a cleaning device and the like to form an image forming unit, and a paper feed cassette for supplying transfer paper is disposed below the unit.

Further, the color image forming apparatus of the present invention has a so-called clamshell structure in which an image forming means such as an exposure device or an upper housing including the unit and the like can be opened with respect to the apparatus main body including the paper feed cassette.

Here, the feature of the present invention is that the upper housing is opened to the apparatus main body at the time of jam clearance, component inspection, component replacement, and the like, and the unit is exposed to the outside when the unit is pulled out from the apparatus main body or the upper housing. For example, an object of the present invention is to protect a surface of an image forming body, such as a charging unit, a transfer unit, and an exposure unit, safely and reliably by a shutter member. Therefore, the shutter member for protection stops opening and closing directly in conjunction with opening and closing of the upper housing or insertion and removal of the unit including the image forming means, and the shutter member in conjunction with insertion and removal of the sheet cassette. Outside the opening and closing of the
The upper housing is opened and closed and a unit including the image forming unit is inserted and removed.

For example, the shutter member is driven in conjunction with the pull-out operation of the sheet cassette to shield the exposed surface of the image forming body.When the exposed surface is shielded, the opening and closing of the upper housing is performed. The cassette can be inserted and removed. Therefore, when the exposed surface of the image forming body is not shielded, that is, the upper housing is not erroneously opened and the unit is not pulled out while the exposed surface is being exposed.

In order to avoid malfunction, the safety lamp is interlocked with the opening and closing of the shutter member in consideration of the case where the interlocking mechanism of the paper cassette with the upper housing or the interlocking mechanism with the unit has a failure. The safety lamp may be turned on when the shutter member is blocking.

Next, in the color image forming apparatus of the present invention, preferably, a method described in each of the publications such as the above-mentioned JP-A-1-76076, that is, a toner image of each color is formed by superimposing on the image forming body, In this case, batch transfer is performed on a transfer material. In this case, there is an advantage that a color image having a high resolution can be stably supplied.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to examples, but embodiments of the present invention are not limited thereto.

(Embodiment 1) FIGS. 1 and 2 are diagrams for explaining the present embodiment.
FIG. 1 shows an upper housing 2 including an image reading system unit A and a laser writing system unit B with respect to an apparatus main body 1 including a paper feeding yarn unit D, a paper conveying system E, a fixing unit 45 and a process unit 3. FIG. 2 is a cross-sectional view of the color copier when the lid is closed, and FIG. 2 is a cross-sectional view of the color copier when the upper housing 2 is opened with respect to the apparatus main body 1.

Image reading system unit A incorporated in the upper housing 2
Then, the color original 11 on the original table 10 was optically scanned by the light source lamp 12 traveling at the speed of V, and was reflected by the reflection mirror 13. The reflected light was further reflected by V mirrors 14 and 15 running at V / 2 and introduced into an optical information conversion unit 16. The unit 16 incorporates a lens, B (blue), G (green), and R (red) three-color separation prisms and three CCDs for each color photoelectric conversion. Here, it was converted into an electrical signal of three colors B, G, and R. The electrical signals of these three colors are output to the next image processing device 17, where color correction, color extraction, and digital conversion are performed.
Digital signals of four colors (yellow), M (magenta), C (cyan), and BK (black) are obtained. These digital signals are obtained every one scanning of the color original (one rotation of the image forming drum). One color image signal, in this case, a Y image signal, was selected and output to the next laser writing unit B. In the unit B, the laser light of the semiconductor laser device 20 is modulated by the Y image signal, and the obtained modulated laser light is deflected by a polygon mirror 22 rotated at a high speed by a motor (not shown), and an f-θ lens 23, an optical latent image was formed on the image forming drum 30 which had been uniformly charged in advance by the charger 34 via the reflecting mirror 24 to form an electrostatic latent image.

By the way, the process unit 3 incorporated in the apparatus main body 1 includes an image forming drum 30, a charging device 34, a Y developing device 35, an M developing device 36, a C developing device 37, and a BK developing device 38 arranged on the periphery of the drum. A cleaning device 39 including a cleaning blade 39A and a cleaning brush 39B is integrally included. The unit 3 can be inserted into and removed from the apparatus main body 1.

The electrostatic latent image formed on the image forming drum 30 in the process unit having the above-described configuration is reversibly developed in a non-contact manner by a Y developing device 35 at the first rotation of the image forming drum 30 to form a Y toner image. Was formed. Thereafter, the cleaning device is rotated with the cleaning device turned off, and is recharged by the charger 34. In the second rotation of the image forming drum 30, laser exposure using the M image signal and development by the M developing device 36 are performed. Similarly, an M toner image was formed so as to overlap the Y toner image. Thereafter, in the same manner, at the third and fourth rotations of the image forming drum 30, laser exposure based on the C image signal and the BK image signal, and development by the C developing device 37 and the BK developing device 38 are repeated, so that the Y toner image is obtained. And the C toner image and the BK toner image were superimposed on the M toner image to form a color toner image.

The color toner image is sent out from the paper feed cassette 40 of the paper feed system unit D by the paper feed roller 41, and is transferred by the timing roller 42 onto the transfer paper conveyed in timing with the image formation by the action of the transfer pole 43a. Was.

The transfer paper on which the color toner image has been transferred is a separation pole 43b.
The toner image was separated from the image forming drum 30 by the action of the separation claw 43c, conveyed to a fixing unit 45 by a conveyance belt 44, fixed to form a color image, and discharged to a paper discharge tray 46.

Here, in the color image forming apparatus of the present embodiment, the shutter member 61 is linked with the insertion / removal of the sheet feeding cassette 40 into / from the apparatus main body 1.
, The upper housing 2 is opened and closed, and the process unit 3 is inserted and removed in the front-rear direction. The interlocking mechanism is shown in FIG. 3, which shows a sheet cassette 40 loaded in a cassette storage section. In the figure
Reference numeral 51 denotes a control plate having long holes 52a and 52b, and pins 53a and 53b extending from the apparatus main body are inserted through the long holes. Here, the control plate 51 is pulled by a tension spring 53 provided at an upper portion thereof, and is urged to move rightward in the drawing via the elongated holes 52a and 52b. However, in the process of loading the paper cassette 40, the control plate 51 is moved to the left end by the engagement with the stopper 54 provided on the cassette, and is stopped at that position.

On the other hand, a lever 62 and a tension spring 63 are connected to the right end of the shutter member 61 in the drawing.
The shutter member 61 is moved to the left end portion against the spring 63 by the engagement and movement of the projection 55 and the lever 62, and the opening 61b of the shutter member 61 is moved to the exposed portion 31 of the image forming drum 30. , So that an image can be formed.

Further, in this state, the locking member 56a for moving the process unit 3 up and down by the spring pressure provided on the projection 55 is fitted in the engagement groove 56b and cannot be pulled out.
Is closed, and the latch 70 of the upper housing 2 is a latch.
71, and is set at a predetermined position with respect to the apparatus main body 1;
72 protrudes upward to prohibit the latch 70 from being disengaged from the latch 71, making it impossible to open the upper housing 2. The rod 72 is held by the metal body 73 on the apparatus main body 1 and the amount of vertical movement of the rod 72 is restricted by the lowering ring 74 and the lowering ring 75.

Next, when it becomes necessary to pull out the process unit 3 for component replacement and jam clearance, first, the cassette 40 is pulled out in the direction of the arrow (rightward in the drawing). At this time, the projection 56 on the cassette 40 is removed from the rod 72, and the rod 72 descends until the ring 74 reaches the metal 73, so that the latch 70 can be disengaged from the latch 71, and the upper housing 2 can be opened to the apparatus main body 1.

The stopper is moved by the rightward movement of the cassette 40.
54 is also retracted, the control plate 51 is pulled by the spring 53, and the pins 53a, 53
b moves rightward in the drawing by sliding in the slots 52a and 52b, and the pins 53a and 53b reach the left ends of the slots and stop. With the movement of the control plate 51, a locking member 56a for locking the process unit 3 is removed from the engagement groove 56b, and the unit 3 can be inserted and removed from the apparatus main body. Further, the shutter member 61 is pulled by the spring 63 and moves rightward in the drawing, and the exposed surface shielding portion 61a of the shutter member reaches the exposed portion 31 of the image forming drum 30 and is stopped. After the exposed surface 31 of the image forming drum 30 is protected by the shutter member 61, the latch 70 is manually removed to open the upper housing 2 upward. Next, the process unit 3 is pulled out, the jam is processed, and parts are replaced.

At the time when the jam processing and the component replacement are completed, the process unit 3 is first mounted on the apparatus main body 1, then the upper housing 2 is closed, and the latch 70 is manually engaged with the latch 71. Next, the paper feed cassette is loaded into the apparatus main body. In the process, the shutter member 61 is moved to the shielding portion 61 as described above.
The process unit 3 is moved from the position a to the opening 61b, locked so that the process unit 3 cannot be pulled out by the locking member 56a, and the release of the upper housing 2 is prohibited by the abutment of the rod 72.

The control plate 51 and the rod 72 are installed and operated at the center of the sheet cassette 40 in the width direction (vertical direction in the drawing).

In this embodiment, the OPC photosensitive drum 30 is rotated four times, and Y, M, C, B
A four-color toner image of K was formed on the drum, and this was transferred and fixed on A4 transfer paper to form a color image at a speed of 10 parts. At this time, the charge on the photosensitive drum 30 is -700 V, and the charged latent image formed by the semiconductor laser light is developed using a two-component developer, and a bias of DC component -500 V, AC component of 3 KHz and 1 KV is applied. It was carried out in a non-contact, reversal development mode below. In this embodiment, the process unit 3 was pulled out every 25,000 color copies, the developer was replaced, and color copying was performed up to 100,000 copies. However, high quality color images were obtained without fatigue deterioration of the photoreceptor. .

(Embodiment 2) FIGS. 4 and 5 are cross-sectional views of a color printer for explaining the present embodiment. FIG. 4 shows a state in which an upper housing 90 is closed with respect to an apparatus main body 80. FIG. 5 shows a state where the lid is opened.

The apparatus main body 80 includes a laser writing system unit 107, a paper feed cassette 114, a transfer paper transport system 115, a lock member 160 of a process unit K described later, a charger 106, a transfer pole 112, and a fixing device 1.
18, a paper discharge system 119 and a shutter member 151 are included. The upper housing 2 also includes a process unit K,
0 is included, and the upper housing 2 can be opened around the shaft 121 as shown in FIG. The process unit K
Includes a photoreceptor belt 101, a cleaning device 113, a Y developing device
A developing unit including a developing unit 108, an M developing unit 109, a C developing unit 110, and a BK developing unit 111, a shutter member 152, and the like are included.

In the color printer of this embodiment, the Y signal of the Y, M, C, and BK color image signals output from an external device such as a CPU
The laser light emitted from 40 was modulated, and the modulated laser light was introduced into laser writing unit 107. The unit 107
In the above, the laser light is reflected by a polygon mirror 107B rotated at high speed by a motor 107A, and the reflected light is previously charged through the f-θ lens 107C and the reflection mirrors 107D and 107E.
Exposure was performed on the photoreceptor bell 101 to which uniform charging was imparted by 06 to form an electrostatic latent image. This electrostatic latent image is developed by a non-contact reversal developing method by a Y developing device 108, a Y toner image is formed on the belt 101, and the other developing devices
The belt 101 was rotated with the cleaning device 113 and the transfer device 117 released, and was recharged by the charger 106. In this cycle, the image exposure based on the M, C, and BK signals and the development by the M developing unit 109, the C developing unit 110, and the BK developing unit 111 are repeated by rotating the photosensitive belt 101 two, three, and four times. In the same manner as in Example 1, a color toner image in which the toner images of the respective colors were superimposed was formed. The color toner image is supplied from a paper supply cassette 114 by a paper supply roll 116 and is transferred onto a transfer paper conveyed through a conveyance path 115 and a timing roller 117.
The image was transferred by the action of, and was heat-fixed by the fixing device 118 to form a color image. The photoreceptor belt after the transfer was cleaned by the blade 113A and the roll brush 113B of the cleaning device 113 in the operating state, and continued to form the next image.

The color image after fixing is conveyed by the rolls 119A and 119B of the paper discharge system 119 and discharged onto the paper discharge receiver 120.
The photoreceptor belt 101 includes a guide member 104 and a transport roll.
Images were formed by being conveyed while being stretched by tension rolls 102 and 103.

Next, a description will be given of the lock member 160 which inhibits the insertion and removal of the shutter members 151 and 152 and the process unit K and the opening of the upper housing 2 which are features of the present invention.

The paper feed cassette 114 is loaded into the apparatus main body 80 as shown in FIG. In the process of loading, when the micro switch 114B (the micro switch 114C is separated by the cam) is turned "on" by the projection 114A provided on the cassette 114, a timer is operated to activate the reverse motors 151C and 152C.
To actuate the shutter members 151 and 1 from the original rolls 151A and 152A urged counterclockwise by a spring.
52 is wound on winding rolls 151B and 152B for a predetermined time,
The shutter members 151 and 152 are opened.
Also, by the time the loading is completed, the projection 159 provided on the paper feed cassette 114 pushes up the rod 161 of the lock member 160 against the spring 168, and the lower end of the lever 162 against the spring 165 in conjunction therewith. Push up. Here, the lever 162 is rotated clockwise about the shaft 167. At the same time, the engaging member 162a connected to the shaft 167 is also rotated clockwise. Engagement locking is performed by the locking member 166 at the lower end. Thus, the drawer of the cassette K and the opening of the upper housing including the cassette K are prohibited.

Next, when the opening / closing door 170 is opened and the sheet cassette 114 is pulled out, the projection 159 is disengaged from the rod 161 and the ring 164 is lowered until reaching the upper surface of the holding device 163, and the lever 162 and the engaging member 162a are moved by the spring 165. The rotation of the shaft 167 causes the engagement with the locking member 166 to be released, and the process unit K and the upper housing can be opened.

In the process of pulling out the paper feed cassette 114, the preceding micro switch 114B is moved to a non-contact position by a cam device (not shown), and the next micro switch 114C is pressed on by the projection 114A, and the reverse motors 151C and 152C are turned on. It rotates in a reverse direction through a timer for a certain period of time and rewinds by the attractive force of the original roll roll spring to shield the exposed surface of the photoreceptor belt. The exposed surface is the surface of the photoconductor of the charger 106 and the image exposure unit. In the process of loading the cassette 114, the microswitch 114C is retracted by the action of a cam (not shown), and at the same time, the microswitch 114B is returned to the operating position. With this configuration, the protection of the exposed surface of the photoreceptor belt is ensured, and a high-quality color plant can be obtained over a long period without fatigue deterioration of the photoreceptor belt.

In this embodiment, a color plant of 100,000 sheets was created using the OPC photoreceptor belt while exchanging the developer by opening the upper housing and pulling out the process unit in the same manner as in the first embodiment. A plant was obtained.

〔The invention's effect〕

As is clear from the above description, the protection of the exposed surface of the photoreceptor by the shutter member or the like is always performed with sufficient safety measures so that malfunction does not occur. The effect is that a high-resolution color image can be stably supplied.

[Brief description of the drawings]

1 and 2 are cross-sectional views of a color copying machine illustrating a first embodiment. FIG. 3 is a cross-sectional view illustrating a mechanism in which a shutter member is opened in conjunction with insertion and removal of a sheet cassette of the color copying machine. FIG. 4, FIG. 4 and FIG. 5 are sectional views of the color printer according to the second embodiment. 1,80: Main body of device, 2,90: Upper housing A: Image reading system unit 3, K: Process unit 20,107: Laser writing system unit 30,101: Image forming body (photosensitive drum, photosensitive belt) 35,36, 37,38,108,109,110,111 Developing device 39,113 Cleaning device 40,114 Paper feed cassette, 43a, 112 Transfer pole 51 Control plate 61,151,152 Shutter member 56,159,114A Projection, 72 Rod 160 Lock member 114B, 114C Micro switch

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-59-34546 (JP, A) JP-A-63-43171 (JP, A) JP-A-61-219965 (JP, A) 111861 (JP, A) JP-A-1-172856 (JP, A) JP-A-3-132267 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 15/00 550- 556 G03G 15/01 G03G 21/00 350-354 G03G 15/00 510-534

Claims (4)

(57) [Claims] An image forming means including at least an image forming body, a plurality of developing devices provided on a peripheral edge of the image forming body, a cleaning device, and an exposing device; and a sheet feeding device below the image forming body. In the color image forming apparatus including a cassette, the image forming body is provided with a shutter member for protecting an exposed surface of the image forming body, and the shutter member is interlocked with the insertion and removal of the sheet feeding cassette. And a color image forming apparatus that is opened and closed. 2. An image forming means including at least the image forming body, a plurality of developing units, and a cleaning device is formed as a unit, and insertion and removal of the unit is operated in conjunction with insertion and removal of the sheet cassette. 2. The color image forming apparatus according to claim 1, wherein: 3. An apparatus body including the sheet cassette, wherein an upper housing including at least one of the image forming means is provided so as to be openable and closable. 3. The color image forming apparatus according to claim 1, wherein the color image forming apparatus is operated in conjunction with insertion / removal. 4. A plurality of operations of the image forming means to form a color toner image on the image forming body by sequentially superimposing the respective color toner images, and collectively transfer the color toner images onto a transfer material. Claims 1 to form a color image by
Item 4. The color image forming apparatus according to any one of Items 3 to 3.