JPH0272985A - Page printer - Google Patents

Abstract

PURPOSE:To arrange vertically a paper feeding passage, at the time of printing, and minimize the possibility of contamination of a printing paper by disposing a developing unit, a photosensitive drum unit, a fixing unit and paper-discharging rollers in that order from the upper side. CONSTITUTION:A printing paper discharged from a transferring unit 51, with the leading end thereof in contact with a guide member 52 of a cover body, is moved downward with the back side thereof along the guide member 52 as printing is conducted in an increasingly larger area. The paper is then fed into a fixing unit 44 while maintaining a curved condition, and a toner adhered to the face side of the paper is fixed. The paper is fed to the fixing unit 44 in the condition where the side of the paper to which the unfixed toner is adhered is opposed to a main body of a casing with a gap maintained therebetween, so that the toner adhered to the face side of the paper is not rubbed against the main body during the feeding of the paper to the fixing unit 44, in which the toner is fixed. The paper discharged from the fixing unit 44 is guided by a guide member 48, and is discharged through a paper- discharging port 3 by paper-discharging rollers 2, with the printed side down.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a page that records characters and patterns on paper based on the principle of electrophotography by irradiating a photoreceptor with a light beam controlled by a data signal. Regarding printers.

(Prior art) In order to meet the demands for improved print quality and printing speed, a light beam is controlled according to print data to form a latent image on a photoreceptor drum, colored toner is attached to this and printed on printing paper. A page printer that uses the principle of so-called serography, which fixes images, has been put into practical use.

In consideration of ease of maintenance, etc., such a page printer has a horizontal hundred-shaped housing M divided into two members N and Q that can be expanded into a crocodile mouth shape, as shown in FIG. The optical writing unit is housed in the half Q, and the photosensitive drum, developing unit, etc. are housed in the other N, and the path from one side of the housing to the other is used as a paper transport path, and the paper cassette is placed on the negative side. It is configured as a so-called clamshell type, in which printing paper is supplied from the printer.

(Problem to be Solved) For this reason, the light beam generation unit and the photosensitive drum are not positioned via the hinge mechanism Sa of the housing M, which not only tends to reduce the relative positioning accuracy of both. However, there is a problem in that in order to secure a paper stock section and a printing path section, a floor area that is at least twice as large as that of the printing paper is occupied.

In order to solve such problems, the applicant has
As shown in Japanese Patent No. 234167, a page printer has been proposed in which the paper conveyance path is substantially vertical, and a light beam generating unit and a photosensitive drum unit are housed on the base side.

According to such a device, it is possible to reduce the installation area and improve the positioning accuracy of the light beam generating unit and the photosensitive drum. For such printers,
Since the units are arranged vertically, there is a problem that the toner scattered from the photosensitive drum unit may adhere to other units and stain the printing paper.

The present invention has been made in view of the above circumstances, and its purpose is to reduce the installation floor area, maintain positioning accuracy of the light beam emitting unit and the photoreceptor drum, etc. To provide a page printer capable of preventing stains on printing paper as much as possible.

(Means for solving the problem) In order to solve this problem, we installed a gate roller, a developing unit, a photosensitive drum unit, a fixing unit, and a paper ejection roller in the order from the top of the housing, and also installed an optical writer on the rear side. In addition, a completion plate was provided between the photoreceptor tram unit and the fixing unit.

(Function) Since the developing unit, photoreceptor drum unit, fixing unit, and paper ejection roller are arranged in order from the top, the paper movement path during printing is vertical, reducing the floor space and reducing the space between these printing paper and paper. The unit with two units is located in the open part of the front of the housing, and the unit that handles the printing paper in cooperation with these units is located on the lid, so opening the lid allows you to easily change the path of the printing paper. The photoconductor tram and the optical writing unit, which require rough positioning accuracy, can be placed in an open state, and high positioning accuracy can be maintained. Roughly, the toner scattered from the photoconductor drum unit is stopped by the shielding plate.
It is prevented from entering the unit located below,
Contamination of printing paper is prevented.

(Example) Therefore, the details of the present invention will be explained below based on the illustrated example.

Figure 1.2.3.4 is a perspective view showing an embodiment of the present invention;
and a cross-sectional view, in which the reference numeral in the figure is a housing that houses the printing mechanism, and the lower part of the side that will be in front when sterilized is a paper ejector that ejects the printing paper from the paper ejection roller 2.2.2. A lid body 4 is attached to the opening 3 so that it can be opened and closed by a hinge so as to straddle the opening 3, and side plates 5.5 for supporting various units are provided on both sides of the interior, and guide mechanisms 1 and 7.7 are provided roughly at the top.
A cut sheet feeder 6 is provided which is movable by. Further, a space 9 is provided on the side of the housing body 1, in this embodiment, on the right side when facing the front, separated by a side plate 5 and openable and closable by a lid 8, in which a control circuit board and an external storage medium reading device can be accommodated. Additionally, a control panel 11 consisting of operation switches, borders, etc., and an external storage medium insertion slot 12 are provided on the front surface.

A paper guide plate 15 is disposed on the front side of the housing body 1, and the paper guide plate 15 is connected to a paper receptacle 14 whose upper end is expanded upward, and a gate roller ]7, a photoreceptor drum unit]8 are disposed in order from the top, and A fixing unit 4 is installed across a shielding plate 43, which will be described later.
4 are arranged.

FIG. 6.7 shows an embodiment of the above-mentioned photosensitive drum unit, in which reference numeral 21 has handles 22.22 on both sides of the front part, and side plates 5.5 of the housing body 1. A photoreceptor drum 24 that engages with the drive mechanism of the main body is rotatably attached to one end by a carrier 23, and a blade 25 that contacts the surface of the drum 24 near the lowest point of the photoreceptor drum 24. , a waste toner tank 26 for storing future toner is integrally attached thereto. Note that the reference numeral 27 in the figure indicates the waste toner tank 26.
The waste toner detector is operated by a detection lever 27a that rises when the toner is full.

Returning to the front blade again, a developing unit 30 is disposed on the back side of the paper guide plate 15 so that the shutter 32 of the toner supply port is exposed when the cut sheet feeder is retracted (FIG. 5).

Around the photosensitive drum 24, a magnetic brush on the surface of the magnetic sleeve 35 of the developing unit 30 is in contact with the photosensitive drum 24, and the bottom surface 31a of the container 31 of the developing unit 30 is in contact with the magnetic brush on the surface of the magnetic sleeve 35 of the developing unit 30.
A charging unit 38 is disposed at a constant interval in the circumferential direction, and a static eliminating unit 3 is roughly located upstream of the charging unit 38 in the rotational direction.
9 are arranged.

Reference numeral 40 denotes a light N-included unit, which is disposed in a rear space whose front and rear parts are divided by a partition wall 41 and a second partition wall 49, which will be described later.
1a and the surface of the photoreceptor drum 24 through the gap between the developing unit 30 and the charging unit 38.

Below the photoreceptor drum unit] 8, there is a partition wall 41 that slopes downward from the front side to the rear side as shown in FIG.
A shielding plate 43 is closely fixed to the side plate 5.5, and a groove 42 for accommodating waste toner is formed at the joint thereof, and a second gap v49 is provided below the groove 42 to protect the housing. It is structured so that it is largely divided into front and back, and the space on the front side is divided into two. The space below the housing, which is divided into two vertically by this shielding plate 43, is
A fixing unit 44 consisting of a heating roller 45 and a pressure roller 47, and an exhaust fan 46 are provided.

A paper guide 48 is provided on the ejection side of the fixing unit 44, and the printing paper that has been vertically moved is guided to the paper ejection roller 2.
．． A path for transporting the paper to the paper discharge port 3 via the paper outlet 3 is formed.

On the other hand, on the inner surface of the lid body 4, there is a paper detection lever 16 that operates a paper detector (not shown) from above, a pinch roller 50 that contacts the gate roller 17, and a transfer roller that faces the photosensitive drum 24 on the downstream side of the magnetic sleeve 35. In addition to disposing the unit 51, a guide member 52 having a plurality of ribs 52a concave in the center arranged in the width direction of the paper is provided on the path from the photoconductor drum 24 to the fixing unit 44. The cover 4 is configured so that the sheet discharged from the cover 24 is convex.

6 is the above-mentioned cut sheet feeder provided at the upper part of the housing body 1 by a parallel link mechanism 7.7, and is located at the paper feeding position (
A plurality of paper feed rollers 61 and 62 are provided in parallel to the front and back on the base 60, which can be set in two positions: a retracted position (Fig. 3) and a retracted position (Fig. 5). Paper hoppers 63 and 64 are vertically arranged to bring the lower ends of the paper into elastic contact with the paper feed rollers 6] and 62, and guide members 65 and 66 are extended from the lower ends of the paper feed rollers 6] and 62 to the main body side support opening 14. It is composed of Further, the receiver is provided with a manual feed port 68 at a position substantially above the port 14 by attaching guide members 67, 67 so as to be movable in the width direction. Note that reference numeral 69 in the figure indicates a locking member for fixing the base 60 to the main body 1.

In this embodiment, when the size of the paper to be printed is selected, one of the corresponding paper feed rollers 6 and 62, for example 62, rotates and one sheet of paper is taken out from the paper hopper 64. It is transferred to the main body 1 side by a guide 66. When the leading edge of the paper reaches the upper surface of the housing body 1, the upwardly expanded receiver enters the opening 14, is guided by the guide plate 15, moves the body downward, and comes into contact with the gate roller 17. At this stage, the paper is fed further and is bent, so the paper detection lever 16 is pressed. As a result, a signal is output from the paper detector, and the gate roller 17 rotates to bring the paper to the standard position, and then roughly moves the paper downward.

On the other hand, data to be printed is input to the control circuit board to control the light beam generator 40, and a latent image is formed on the photoreceptor drum 24 based on the data. This latent image is formed on the photoreceptor drum 2.
4, the toner is adhered by the developing sleeve 35 and visualized. This developed image is moved to a position facing the transfer unit 5 by the rotation of the photoreceptor tram 24, and is transferred to the printing paper located here.

The printing paper that has come out of the transfer unit 5 is attached to the lid 4 with its leading edge.
as the print area expands, the back surface moves roughly downward along the guide member 52. In this way, while maintaining the curved state, the toner enters the fixing unit 44, and the toner adhering to the surface is fixed. As a result, the printing paper is transported to the fixing unit 44 with the unfixed toner-applied @ rough surface maintaining a gap from the main body side of the casing, and the toner adhered to the surface is removed. The toner is moved to the fixing unit 44 and fixed without being rubbed against the main body side. The paper exiting the fixing unit 44 is guided by a guide member 48 and is ejected face down from the paper ejection port 3 by a paper ejection roller 2.2 with the printed side facing downward. On the other hand, high-temperature air due to waste heat from the fixing unit 44 during this fixing process and moisture evaporated from the printing paper are transferred to the shielding plate 43, the photosensitive drum 24 above the second partition wall 49, and the optical writing unit 40. It is prevented from entering the room and is quickly discharged to the outside by the fan 46.

Also, among the toner that adhered to the photoreceptor tram 24 during the development process, the toner that was not transferred to the printing paper is scraped off by the plate 25 below the photoreceptor drum 25 (J), and the waste toner directly below is collected by gravity. It is accommodated in a tank 26.

During this scraping process, the toner scattered to the outside from the waste toner tank 26 is stopped by the Ae plate 43, enters the unit located below, and enters the optical writing unit through the rear opening v4 +, 49. 40 will be blocked.

Toner leaked during the printing process is removed from the side plate 5.5, the partition wall 41,
The particles are prevented from scattering as much as possible by the shielding plate 43, and are finally accumulated in the groove portion 42.

On the other hand, if a paper jam occurs during printing, when the lid 4 is opened, paper holding members such as the pinch roller 50, transfer unit 5], paper guide member 52, etc. Since the printing paper transport path is opened at the front of the apparatus, paper stopped in the middle of the printing path can be easily taken out.

When the removal of the paper is completed, the next printing is possible by lightly returning the lid 4 to the main body. Of course, when the lid is opened and closed, the optical writing unit 40 and the photosensitive drum 24 remain stationary on the side of the main body, so the optical writing unit 40 and the photosensitive drum 24 require precise positioning of the ends. This will not result in a situation where there is a misalignment between the two.

In this embodiment, the shielding plate and each of the partition walls are constructed as separate bodies, but it is clear that the same effect can be obtained even if they are formed as an integral structure by press working, injection molding, or the like.

(Effects) As explained above, in the present invention, a gate roller, a developing unit, a photosensitive drum unit, a fixing unit, and a paper ejection roller are arranged in order from the top of the housing, and an optical writing unit is arranged on the rear side. Since a shielding plate is disposed between the photoconductor tram unit and the fixing unit, the paper movement path during printing is controlled by the unit arrangement consisting of the Getro roller, developing unit, photoconductor drum unit, fixing unit, and paper ejection roller in order from the top. The toner can be configured vertically to minimize the installation floor area of the device, while preventing the toner tX scattered from the photoreceptor drum unit from being caught and intruding into the lower unit. Not only can it prevent contamination of the printing paper, but it can also prevent waste heat from the heating roller of the fixing unit installed at the bottom and water vapor from the printing paper generated during fixing from entering the photoreceptor drum. Thus, deterioration of the photoreceptor drum can be prevented as much as possible.

[Brief explanation of the drawing]

Figures 1 and 2 each show an embodiment of the present invention. Figure 1 shows the exterior of the printer equipped with a cut sheet feeder, and Figure 2 shows the photoreceptor with the front lid opened. Perspective view showing the drum unit pulled out, Section 3.4.5
The figures show cross-sections of the same device as above, with Figure 3 showing it in a printable state, Figure 4 showing it in a state with the lid open, and Figure 5 showing it in a state where the lid is open.
The figure is a cross-sectional view showing the cut sheet feeder in a retracted state, Figures 6 and 7 are perspective views and cross-sectional views respectively showing one embodiment of the photoreceptor drum unit, and Figure 8 is a cross-sectional view showing one embodiment of the shielding structure. The perspective view shown and FIG. 9 are diagrams showing an example of a conventional page printer. 40... Optical writing unit 42... Groove portion 44... Fixing unit 49... Partition wall 38... Charging unit 4]... Partition wall 43... Shielding plate 46... Exhaust fan 5] ...Transfer unit 61.62...Paper feed roller 63.64...Printing paper hopper 65.66...Guide plate 68...Manual feedlot...Housing body 3...Paper output port 4 ... Lid body 5.5 ... Side plate 6 ... Cut sheet feeder 8 ... Lid 9 ... Control unit accommodation space 1] ... Control panel 12 ... External storage medium insertion slot] 4 . . . Paper tray is an opening ] 5 . . Paper guide plate] 7 . . . Gate roller 18 . . . Photosensitive drum unit 24 . . . Photosensitive drum 25 .
...Developing unit 35...Developing sleeve Applicant Seiko Even Co., Ltd.

Claims (2)

[Claims] (1) A gate roller, a developing unit, a photoreceptor drum unit, a fixing unit, and a paper ejection roller are arranged in the housing in order from the top, and an optical writing unit is arranged on the rear side, while the space between the photoreceptor drum unit and the fixing unit is arranged. A page printer equipped with a shielding plate. (2) A partition wall is provided between the gate roller, developing unit, photoreceptor drum unit, fixing unit, paper ejection roller and the optical writing unit on the rear side, and a shielding plate is provided between the photoreceptor drum unit and the fixing unit. A page printer that is installed.