JPH02234169A - Image forming device - Google Patents

Abstract

PURPOSE:To simplify a carrying path of a recording paper for ejecting the paper face down and to miniaturize the device main body by providing a transferring means in the upper direction of a photosensitive body and providing one or more of the transferring means, a fixing means, or an ejecting part of the recording paper in a movable body. CONSTITUTION:The device main body 100 is constituted from a static body and the movable body, and in the movable body, when it is closed against the static body, the transferring device 5 is provided in a position facing it in the upper direction of the photosensitive drum 1, one of a resisting rollers 18 and 19, paper ejecting rollers 23 and 24, and the fixing device 9 are provided. That is at least one or more of the transferring means 5, the fixing means 9, or the paper ejecting parts 23 and 24 of the recording paper are provided in the movable body. Thus, the recording paper carrying path for the face down paper ejecting can be simplified and the device main body 100 can be miniaturized.

Description

Detailed Description of the Invention [Industrial Application Field 1] The present invention relates to a laser beam that irradiates a photoreceptor with a light beam controlled by an image information signal and records characters or bullets on a recording paper using an electrophotographic method. Related to image forming devices such as printers, LCS printers, LED printers, and facsimile machines. rPrior art] Printers, copying machines, etc. that use a process in which an electrostatic latent image formed on an electrophotographic photoreceptor through a charging and photoimage exposure process is visualized on a recording paper through a development, transfer, and fixing process. Image forming devices are known. An example of an image forming apparatus according to the prior art described above will be described below with reference to the drawings. FIG. 4 is a cross-sectional view schematically showing the main parts of a conventional electrophotographic laser beam printer. In the figure, 1 is a photosensitive drum made of a drum-shaped photoconductor. When the photosensitive drum 1 is rotationally driven in the direction of arrow B, the charging device 2
The drum surface is uniformly charged. Next, a static-1 latent image is formed by scanning image exposure with a laser beam modulated by an image signal. The electrostatic latent image is visualized by toner when passing through the developing device 4. The toner image formed in this way is transferred to the transfer device 5.
The toner image is transferred from the paper feeding device 8 onto the recording paper fed to the transfer position in synchronization with the toner image on the photoreceptor drum l. After the recording paper has been transferred, it is separated from the drum and sent to the fixing device 9, and then the recording paper is conveyed along the conveyance path of approximately 180 mm.
The paper is then discharged in a so-called face-down state to a paper discharge section 10 provided at the top of the main body of the apparatus. The transport route is shown by a broken line. [Problems and Objectives to be Solved by the Invention 1 However, in the conventional image forming apparatus having the above-mentioned configuration, in order to realize face-down paper ejection, the withdrawal path after fixing is complicated and mechanical parts for that purpose are required. On the other hand, since the recording paper is conveyed in a sudden bend, there is a high incidence of jams, and it is particularly difficult to convey cardboard, envelopes, etc., which causes wrinkles in the paper. Furthermore, since the recording paper is bent while still retaining heat immediately after passing through both the heating and pressure rollers that make up the fixing device, paper curling occurs, which is particularly noticeable with cardboard and envelopes. It was. On the other hand, in the conventional image forming apparatus described above, the heat source represented by the fixing device is located below the main body of the apparatus, so there is a risk of deterioration of the surface of the photoreceptor, as well as the optical system and developing device. The problem was that it was impossible to avoid the effect on the toner inside the device and cleaning device. The present invention is intended to solve these problems, and its purpose is to improve reliability by simplifying the paper conveyance path, prevent paper jams, and prevent paper from falling into the conveyance path. Provides an image forming device that is easy to handle even when it is clogged, prevents adverse effects caused by heat by improving the layout and configuration of the fixing device, which is a heat source, and can make the device body compact. This is what I am trying to do.
[Means for Solving the Invention] In order to solve the above-mentioned problems, an image forming apparatus of the present invention includes a photoconductor, an exposure device for forming image information as a latent image on the photoconductor, and a device for exposing the latent image. It includes a developing means for forming an image, a transfer means for transferring the developed image onto a recording paper, and a fixing means for fixing the transferred developed image, and includes at least two bodies, a stationary body and a movable body. In the expandable image forming apparatus, the transfer means is disposed above the photoreceptor, and the movable body has at least one of the transfer means, the fixing means, and the recording paper ejection section. It is characterized by having a. [Function] With the above-described configuration, the present invention can simplify the conveying path of the recording paper, downsize the main body of the apparatus, and
Even if recording paper becomes jammed inside the machine, it can be easily removed. Additionally, this configuration allows the fixing device to be placed above the device body, making it possible to suppress the effects of heat on the main mechanisms within the device. In addition, high positioning accuracy can be maintained by arranging the photoreceptor and image exposure device, which require high positioning accuracy, on the stationary body side. [Embodiment] An embodiment of the present invention will be explained below using FIGS. 1, 2, and 3. FIG. 1 is a side sectional view schematically showing the main parts of a laser beam printer using an electrophotographic method according to the present invention. In the figure, parts with the same purpose are indicated by the same symbols. In the figure, 1 is a photosensitive drum made of a photoconductive material such as OPC. 2 is a charging device using corona discharge. 3 is an image exposure device using laser light, which includes a laser light source (not shown), a polygon mirror 11 for sweeping the laser light, a motor 12 for rotationally driving the polygon mirror, an optical system 13 for imaging,
It consists of a reflecting mirror 14, etc. 4 is a developing device that contains toner, which is a developer. 5 is a transfer device that transfers the developed toner image onto recording paper 15. 16 is a paper feed cassette that accommodates the recording paper 15. 17 is a paper feed roller. 18, 19
is the registration roller. Reference numeral 9 denotes a fixing device, which includes a pressure roller 20, a heating roller 22 containing a fixing lamp 2l, and the like. 23 and 24 are paper ejection rollers. 25 is a paper output tray. A cleaning device 6 is composed of a cleaning blade 7 and a waste toner box 26. 27 is a static eliminator. 28 is an exhaust fan. The operation of the laser beam printer configured as described above will be explained in detail below. In FIG. 1, when the photosensitive drum 1 rotatably supported by the printer main body is rotationally driven by a drive source (not shown) in eight directions of arrows, the surface of the drum is uniformly corona charged by a charging device 2. Ru.

On the other hand, the laser beam flux modulated by the image signal is
It is reflected by a polygon mirror 11 rotated at high speed by a motor 12, passes through an optical system 13 and a reflection mirror 14, and sweeps the charged portion on the photoreceptor drum 1 in the longitudinal direction of the drive shaft.
An electrostatic latent image is formed on the drum surface through optical image exposure.
The electrostatic latent image is visualized by toner when it passes through a developing device 4 that forms an air brush. The toner image formed in this manner is transferred by a transfer device 5 using corona discharge onto a recording paper 15 which is fed to a transfer position in synchronization with the toner image on the photoreceptor drum l. Recording paper 15
is stored in the paper feed cassette 16 and the paper feed roller 1
The paper is separated one by one by 7 and is fed between the stopped registration rollers 18 and 19, and waits until the photosensitive drum l
Registration roller 1 starts rotating in synchronization with the toner image above
The paper is fed to the transfer position by 8 and 19. When the recording paper after transfer is further fed, it peels off from the photoreceptor drum 1 due to its own rigidity and enters between the pressure roller 20 and the heating roller 22.The toner image on the recording paper 6 is absorbed by the heat of the fixing device 9. It is fixed by the action of pressure. After fixing, the recording paper is stacked on a paper tray 25 with the image surface facing downward, in the order of printing, by the joint rotation of both rollers of the fixing device 9 and the driving force of the paper ejection rollers 23 and 24, and is ejected. It will be papered. On the other hand, untransferred toner remains on the surface of the photosensitive drum l after the transfer, and this residual toner is removed by a cleaning device 6. After cleaning the drum part, use the static eliminator 2.
7, the static electricity is removed to a certain level by uniform light exposure,
Prepare for the next image creation process. The arrangement positional relationship and characteristics of each image forming means in the image forming apparatus of the present invention due to the above operation will be explained in more detail using FIGS. 1, 2, and 3. The device main body 100 is located at the front when installed from the left side in FIG. 1, and a control panel 29 consisting of operation switches and the like and an external storage medium insertion slot 30 such as an IC card are provided on the upper surface of the front side. At the same time, a paper feed cassette mounting portion puller is formed into which a paper feed cassette 16 containing a recording cassette 15 is inserted and mounted. A paper discharge port 32 for discharging the recording sheets 15 on which images have been formed is provided on the top surface of the apparatus main body 100, and a removable paper discharge tray 25 is provided, and the recording sheets are discharged and stacked in a face-down state. The apparatus body 100 is composed of a stationary body 33 and a movable body 34, and during maintenance such as replenishment and replacement of consumables and paper jam disposal, the apparatus body is moved by a damper mechanism (not shown) as shown in Figure 3. The movable body 34 is expanded upward with respect to the stationary body 33 using the back side of the upper surface as a fulcrum. This opens the inside of the device and allows the above-mentioned processing to be performed easily. Inside the movable body 34, a transfer device 5 is disposed at a position facing above the photosensitive drum 1 when the stationary body 33 is closed, and one of the pair of registration rollers 18, 19 and Paper ejection rollers 23, 24 and a fixing device 9 are provided. Therefore, when a paper jam occurs, the paper path can be opened by expanding the movable body 34, and the jam can be cleared quickly and easily. On the other hand, in this embodiment, a discharge tray 25 is disposed at a predetermined slope on the movable body 34, which also serves as the top door of the apparatus main body 100, so that the recording paper after fixing is not forcibly bent. The haishi paper tray 25 is conveyed and stacked, and the inclination angle of the haishi paper tray 25 is determined by the movable body 3.
4 is set within the angle at which the ejected recording paper does not slide down to the rear of the apparatus main body 100 even when expanded to the maximum extent. As described above, in the paper conveyance path from the recording paper feed to the wandering paper according to this embodiment, the transfer position to the recording paper is provided near the top of the photoreceptor drum 1, and the recording paper is placed on the side of the photoreceptor drum l. The toner image is transferred to the bottom surface of the recording paper at the transfer position, fixed, and then the conveyance direction is slightly shifted upward and the paper is discharged onto the paper discharge tray 25, so it requires a complicated conveyance means and Face-down paper ejection is realized without the need for a path. Approximately 500 W is inside the heating roller 22 of the fixing device 9.
The fixing lamp 2l, which requires a power consumption of 1,000 yen, is contained therein and is disposed above the photosensitive drum 1 and near the paper discharge port 32. On the other hand, an exhaust fan 28 is disposed on the top surface of the apparatus main body 100 above the fixing device 9, and exhausts the hot atmosphere generated by the fixing lamp 21 and the heat from the power supply, motor, electrical transmission parts, etc. to the outside. This makes it possible to minimize the temperature rise of units such as the toner in the photosensitive drum 1, the developing device 4, and the cleaning device 6, which do not like temperature rises, due to heat convection within the device. Heating roller 2
2. A heat shielding cover 35 is disposed around the pressure roller 20 to block radiant heat to the photosensitive drum 1 and the cleaning device 6. By arranging the fixing device 9, which is the largest heat source, above the photoreceptor drum 1, the photoreceptor
This avoids deterioration of toner and the like due to temperature rise, as well as thermal effects on the image exposure device II3, which contains precision optical parts described later. The stationary body 33 of the apparatus includes a photosensitive drum 1, which is the main part of the image forming means, a charging device 2, an image exposure device 3, and a developing device 4.
, a cleaning device 6, a static eliminator 27, etc. are positioned and disposed with respect to a rigid frame of the device (not shown). The image exposure device 3 is disposed at the bottom of the stationary body 33 facing the photosensitive drum 1. Therefore, the relationship between the exposure position and the focus position, which requires accuracy, is ensured with sufficient accuracy, and even when the movable body 34 is opened and closed with respect to the stationary body 33, no positional deviation occurs. In this example,
The movable body is provided with a transfer means and a recording paper discharge tray, which is a discharge section for the recording paper.The paper discharge tray is provided on the stationary body side, and when the movable body is expanded, the stacked recording sheets are discharged. It is also possible to make the paper's posture remain unchanged. Further, by disposing it on the side of a stationary body such as a fixing device, it is possible to facilitate the disposal of jammed paper. [Effects of the Invention] As described above, according to the present invention, a photoreceptor, an exposure means for forming image information as a latent image on the photoreceptor, a developing means for making the latent image visible, and a In an image forming apparatus that includes a transfer means for transferring a developed image onto a recording paper and a fixing means for fixing the transferred developed image, the image forming apparatus can be expanded into at least two bodies, a stationary body and a movable body. By disposing the transfer means above the photoconductor and disposing at least one of the transfer means, the fixing means, and the recording paper discharge section on the movable body, face-down discharge is achieved. The conveyance path for paper recording paper can be simplified, mechanical parts can be reduced, and the device itself can be made smaller and lighter. In addition, since the paper path is not bent, the occurrence of paper wrinkles, curls, etc. in cardboard, envelopes, etc. can be avoided, and the jam rate can be reduced. Furthermore, even if journal paper should become jammed inside the machine, the jammed paper can be easily removed by extending the movable body to the stationary body. As a further advantage of the present invention, since the number of mechanical parts arranged on the movable body side is small, the weight can be reduced, and a large-scale damper mechanism that resists gravity and maintains its posture when the movable body is expanded can be avoided. It's not necessary. Furthermore, a photosensitive drum, a developing device, a cleaning device,
Since the image exposure means is disposed on the side of the stationary body of the apparatus, a predetermined optical relationship is maintained, and even when the movable body is expanded during maintenance and inspection, the developing device and cleaning device are
Since the position does not change, there is no risk of toner leaking and scattering. Furthermore, since the movable body is lightweight and the image exposure means is disposed on the stationary body side, the impact and vibration generated upon engagement are slight, and the imaging optical system, optical position,
The risk of having a negative impact on the positioning relationship, etc. is also reduced. Another advantage of the present application is that the fixing device, which is a heat source, can be installed at the top of the main body of the device, which prevents deterioration of the photoreceptor, toner, etc. due to temperature rise, and heat to the image exposure device that contains precision optical components. This has the effect that it is possible to avoid the influence as much as possible, and it is possible to construct a good image forming apparatus that is stable over time and has excellent reliability and operability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view for explaining an embodiment of the image forming apparatus of the present invention. FIG. 2 is a perspective view for explaining the appearance of the image forming apparatus of the present invention. FIG. 3 is a sectional view for explaining a state in which the movable body of the image forming apparatus of the present invention is expanded with respect to the stationary body. Figure 4 is a cross-sectional view for explaining the prior art.・Photoconductor drum charging device ・Image exposure device ・Developing device ・Transfer device ・Cleaning device ・Cleaning blade ・Paper feeding device ・Fixing device ・Paper ejecting section ・Polygon mirror ・Motor 13''・ 1 4 ・ 1 5 ・ 1 6 ・l 7 ・ 1 8, 2 0 ・ 2 l ・ 2 2 ・ 23, 25 ・ 2 6 ・ 2 7 ・ 28 ・ 30 ・ 3 1 ・ 3 2 ・ 3 3 ・ 34 ・ ・Optical system・Reflection mirror・Recording paper・Paper feed cassette, paper feed roller, registration roller, pressure roller, fixing lamp, heating roller, paper ejection roller, paper ejection tray, waste toner box, static eliminator, exhaust fan, control panel, external storage medium insertion slot installation part, Paper ejection port, stationary body, movable body 3 5 ・ ・ ・ Heat shield cover 100 ... device body and above Applicant: Seiko Epson Co., Ltd. Agent Patent attorney Kisaburo Suzuki (1 other person) Figure 2

Claims (1)

[Claims] 1. A photoreceptor, an exposure means for forming image information as a latent image on the photoreceptor, a developing means for making the latent image visible, and a transfer means for transferring the developed image onto recording paper;
a fixing means for fixing the transferred developed image;
In an image forming apparatus that can be expanded into at least two bodies, a stationary body and a movable body, the transfer means is disposed above the photoconductor, and the transfer means, the fixing means, and the fixing means are arranged on the movable body. An image forming apparatus characterized in that at least one of the recording paper discharge sections is disposed.