JPH01185671A - Image recorder - Google Patents

Abstract

PURPOSE:To evade the inside taint of a recorder by directing a transfer part and a photosensitive drum, both of which comprise the recorder, toward the upper part of the recorder so that they can be opened and moved and blocking an opening part formed between a developing unit and a cleaning unit with a cover for preventing toner splashing together with said actions. CONSTITUTION:The part 30 of a cover for the recorder main body is made turnable, centered about a shaft 31 provided at the end of the main body, and when the part 30 is lifted upwardly, a transfer charger 4 and the upper roller 11 of a resist roller pair are positioned outside the recorder together with the part 30. In such a way, transfer paper conveying path is fully opened, and a jammed transfer sheet can be removed when it occurs. By interlocking with the lift of the part 30, an opening part 30 provided between the developing unit 3 and the cleaning unit 5 is blocked with a paper guide 51, whereby the outflow of toner in the units 3 and 5 is prevented. Thus, the taint inside the recorder due to toner splashing can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an image recording device, and in particular to an image recording device in which optical writing is performed on a photoreceptor drum via an optical writing unit with a light beam according to an image information signal. Regarding equipment.

(Prior art) In various image recording devices such as laser printers and facsimile machines, the emission of a laser beam is controlled or modulated according to an image information signal, and the image information beam is applied to a photoreceptor drum as a latent image carrier through an optical writing unit. Optical writing is performed on the photoreceptor drum, thereby forming an electrostatic latent image on the photoreceptor drum. This electrostatic latent image is developed into a toner image by a developing unit, and this toner image is further transferred to transfer paper fed from a paper feeding unit under the action of a transfer charger, and then transferred to a fixing unit. Fixation is performed by. After the toner image is transferred, the toner remaining on the photoreceptor drum is removed by a cleaning unit, and the photoreceptor drum is initialized.

Incidentally, in conventional recording apparatuses of this type, the optical writing unit is provided above the photoreceptor drum, and the optical writing operation is generally performed on the upper side of the photoreceptor drum. Further, the developing unit is provided on the side of the photoreceptor drum, and the transfer charger is placed below the photoreceptor drum, and the transfer portion formed between the transfer charger and the photoreceptor drum is Transfer paper is normally fed with its transfer surface facing upward.

The paper feeding section is arranged so as to protrude further to the side of the developing unit, or is arranged further below the transfer charger. If the paper feed section is arranged so as to protrude to the side of the developing unit, the entire device must be constructed in a long shape, and the paper feed section is arranged below the transfer charger. In this case, there is a problem in that the height of the entire apparatus becomes large because sufficient space is required to make a U-turn of the transfer paper without difficulty.

Furthermore, in the conventional device described above, when the transfer paper becomes jammed in the transfer section or the paper feed path, in order to remove the jammed paper, not only the optical writing unit but also the optical writing unit is used.
It is necessary to open the entire unit housing the developing unit and the photoreceptor drum upward, which poses a problem in operability.

In order to solve this problem, the inventors of the present invention arranged the optical writing unit below the photoreceptor drum and the developing unit, and arranged the transfer charger above the photoreceptor drum. An image recording device has already been proposed that is installed so as to be openable toward the upper side outside the machine. The developing unit and the cleaning unit in this proposed device are arranged to face each other on the side of the photosensitive drum, that is, above the optical writing unit and below the transfer section. The photosensitive drum is moved open through an opening formed between the developing unit and the cleaning unit.

However, in an apparatus having such a configuration, when the photoreceptor drum is moved to open, the opening formed between the developing unit and the cleaning unit is opened toward the outside, and the opening is opened outward. There is a problem in that toner tends to scatter from the area. For example, when replacing the developing unit and cleaning unit together, if the developing unit and cleaning unit are moved after opening the photoreceptor drum, the developing unit opens outward as the photoreceptor drum moves to open. Toner scattering often occurs from the opening between the printer and the cleaning unit, causing contamination inside the machine. In particular, the scattered toner tends to flow into the optical writing unit disposed on the lower side, and if the optical writing unit becomes contaminated with toner, image formation will be greatly affected.

(Purpose) Therefore, the present invention aims to reduce the size of the device and improve its operability, and at the same time prevent toner from scattering from the developing unit or the cleaning unit, thereby improving the reliability of the device. The purpose of the present invention is to provide an image recording device with a

(Structure) In order to achieve the above object, the present invention provides an optical writing unit that forms an electrostatic latent image by optically writing on a photoreceptor drum with a light beam according to an image information signal, and is provided below the photoreceptor drum. A developing unit is disposed above the photoreceptor drum 1, and a transfer section for transferring a toner image obtained by developing the electrostatic latent image onto a transfer paper is disposed above the photoreceptor drum, and further develops the electrostatic latent image. and a cleaning unit for removing toner remaining on the photoreceptor drum after transfer, which is arranged so as to face both sides of the photoreceptor drum above the optical writing unit and below the transfer section. In the forming apparatus, the transfer section and the photoreceptor drum are provided so as to be open and movable toward the upper side outside the machine, and as the transfer section and the photoreceptor drum are opened and moved, the transfer section and the photoreceptor drum are formed between the development unit and the cleaning unit. It has a structure in which a cover for preventing toner scattering is attached so as to close the opening where the toner is scattered.

In an apparatus having such a configuration, first, the developing unit and cleaning unit can be easily exposed by opening the photoreceptor drum toward the outside of the machine upward, and thereby the developing unit and cleaning unit can be operated. In addition, the opening between the developing unit and the cleaning unit, which is opened to the outside as the photoreceptor drum opens, is provided so as to be linked to the opening movement of the photoreceptor drum to prevent toner scattering. It is designed to be closed by a protective cover.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to a laser printer. Surrounding the photoreceptor drum 1 in this apparatus are a charger 2 that uniformly charges the photoreceptor drum 1 along the direction of rotation shown by an arrow, a developing unit 3 that develops an electrostatic latent image, and a developing unit 3 that develops an electrostatic latent image. A transfer charger 4 that transfers the toner image onto a transfer paper, a cleaning unit 5 that removes toner remaining on the photoreceptor drum 1 after the transfer, and the like are sequentially arranged. An optical writing unit 7 is provided so that a writing beam is incident on the photoreceptor drum 1 at a position 6 to expose it.

In this embodiment, the charger 2 and the light beam writing position 6 are
is arranged below the photoreceptor drum 1 , and the optical writing unit 7 is arranged below the photoreceptor drum 1 . Further, the transfer charger S4 is connected to the photosensitive drum 1.
The developing unit 3 is located above the developing unit 3.
The cleaning units 5 are arranged on both sides of the photosensitive drum 1 above the optical writing unit 7 and below the transfer charger 4 so as to face each other. Furthermore, a paper feed cassette 8 for feeding transfer paper to a transfer section formed between the transfer charger 4 and the photosensitive drum 1 is provided further below the optical writing unit 7. Then, the transfer paper is separated from double feeding by the feed roller 9 and the friction bat 1o that is pressed against the feed roller 9, and is sent out one by one.The transfer paper is then made a large U-turn on the side of the developing unit 3, and is placed above the developing unit 3. The paper is fed to the transfer section at the same timing as the image formed on the photoreceptor drum 1 by a pair of registration rollers 11 and 12. A fixing unit 13 is disposed in the transfer paper path after transfer formed on the upper side of the cleaning unit 5, and a paper discharge tray 14 is disposed on the discharge side of the fixing unit 13.
is provided.

In the optical writing unit 7, as shown in FIGS. 1, 2, and 3, the light beam blinked in response to the image information signal emitted from the laser unit 21 is
After being reflected by a mirror 22, the light is incident on a polarizing mirror 24 that is integrally attached to the shaft of a scanner motor 23, and is repeatedly deflected over a certain angular range.

The deflected light is imaged on a straight line by the fθ lens 25 at the incident position 6 on the photoreceptor drum 1, and corrected so that the projection point is moved at a constant speed. The light enters the photoreceptor drum 1 via the second mirror 26 and the cylindrical lens 27, and main scanning is performed by the polarization of this incident light, and sub-scanning is performed by the rotation of the photoreceptor drum 1, resulting in an image information signal. An image corresponding to the image is written to form an electrostatic latent image. The components of the optical writing unit 7 are mounted directly on the base cover 28 of the device. Note that the reference numeral 29 indicates a synchronization detection sensor.

The electrostatic latent image formed on the photosensitive drum 1 is developed and visualized by a developing unit 3, thereby obtaining a toner image.

On the other hand, the transfer paper is fed to a transfer section by a pair of registration rollers 11 and 12, where the toner image is transferred by the action of the transfer charger 4. After the transfer, the transfer paper separated from the photoreceptor drum 1 is fixed by the fixing unit 13 and discharged to the paper discharge tray 14.

After the transfer, the toner remaining on the photoreceptor drum 1 is cleaned by the cleaning unit 5 and prepared for the next image formation.

In this device, as described above, the optical writing unit 7 is provided below the photosensitive drum 1 and the developing unit 3, the automatic paper feeding unit 8 is further arranged below the optical writing unit 7, the transfer section 4 and the registration roller pair 11. 12 is provided above the photoreceptor drum 1, the transfer paper fed from the paper feed unit 8 can be turned around the outside of the developing unit 3 and transferred to the pair of registration rollers 11 and 12 without taking up a large space. The device can be made smaller.

A part 30 of the upper cover of the apparatus main body is rotatably installed around a shaft 31 provided at the right end of the apparatus in FIG. 1, and can be opened by flipping upward. It looks like this. Further, the transfer charger 4 and the upper roller 11 of the registration roller pair are also provided so as to move integrally with the portion 30 of the upper cover. On the other hand, the photosensitive drum 1 and the lower roller 12 of the registration roller pair can be left on the main body of the apparatus when the upper cover part 30 is opened, or can be lifted up integrally with the upper cover. It is supported in such a way that it can be selected. Therefore, the transfer portion or registration roller pair 11.
When the transfer paper jams in step 12, as shown in FIG. The transportation route is completely open,
Jam paper can be easily removed. If the part 30 of the upper cover is configured to be automatically opened by removing a latching member using, for example, a spring (not shown), operability can be improved.

Further, as shown in FIG. 5, if the photosensitive drum 1 and the lower roller 12 of the registration roller pair are also movable together with the part 30 of the upper cover, the cleaning unit 5 and the developing unit The operation when replacing the third etc. will be facilitated. The photosensitive drum 1 is
It is accommodated in a space formed between the developing unit 3 and the cleaning unit 5, and when the photosensitive drum 1 is opened as described above, the developing unit 3 and the cleaning unit 5 are An opening 50 is formed between them.

Next, on the upper side of the cleaning unit 5, a paper guide 51 is provided that guides the transfer paper in the transfer paper path after transfer to the fixing unit 13. The paper guide 51 is formed from an elongated plate-like member, and the edge portion facing the photoreceptor drum 1 side extends in the axial direction of the photoreceptor drum 1 on the upper surface of the cleaning unit 5. It is rotatably installed around a rotation shaft 52. As a result, the paper guide 51 is rotated between the position shown in FIG. 1 and the position shown in FIG.

When the paper guide 51 is in the position shown in FIG. 1, it forms a conveyance path, has a transfer paper guiding function,
When in the position shown in FIG. 5, the tip of the rotating side comes into contact with the upper surface of the developing unit 3, and the hook is passed between the cleaning unit 5 and the developing unit 3, and both units 5 and 5 are placed in the position shown in FIG. It has the function of covering and closing the opening 50 between .3 and 3.

Furthermore, as shown in FIG.
A drive gear 53 is fixed to at least one end of the drive gear 2 . This drive gear 53 can be formed integrally with the rotation shaft 52.

Further, a rack gear 54 that is reciprocated in conjunction with the opening operation of the upper cover portion 30 and the photosensitive drum 1 is meshed with the drive gear 53 . This rack gear 54 extends in the vertical direction, and is attached with a coil spring 55 that applies an upward biasing force. When the upper cover part 30 is closed as shown in FIG. 1, the rack gear 54 is maintained in a lower position against the upward biasing force of the coil spring 55. At the same time, when the upper cover part 30 and the photosensitive drum 1 are flipped upward as shown in FIG. 5, the rack gear 54 is pushed to the upper position by the upward biasing force of the coil spring 55. Then, the paper guide 51 is rotated.

In such an embodiment, when the upper cover portion 30 is closed as shown in FIG.
is maintained in a state where it is pressed downward against the upward biasing force of the coil spring 55. Therefore, the paper guide 51 is positioned above the cleaning unit 5 and forms a conveyance path, and the It functions to guide the paper to the fixing unit 13. On the other hand, from the state shown in FIG. 1 to the state shown in FIG.
When the photosensitive drum 1 is flipped upward, the developing unit 3 and the cleaning unit 5 are exposed to the outside, so that the developing unit 3 can be easily operated.

At this time, the rack gear 54 is pushed to the upper position by the upward biasing force of the coil spring 55 in conjunction with the upward flip-up operation of the part 30 of the upper cover and the photosensitive drum 1, and the rotation of the paper guide 51 An action is taken.

As a result, the rotating end of the paper guide 51 comes into contact with the upper surface of the developing unit 3, and the paper guide 51 is suspended between the cleaning unit 5 and the developing unit 3. As a result, the opening 50 between both units 5.3 is covered and closed by the paper guide 51.

When the opening 50 is closed by the paper guide 51 in this way, the toner in the developing unit 3 or the cleaning unit 5 will not flow out from the opening 50. This prevents the inside of the machine from being contaminated by toner scattering.

(Effects) As described above, the present invention is provided with a cover for preventing toner scattering that opens and closes the opening between the developing unit and the cleaning unit, and this cover prevents the external Since the above-mentioned opening is closed, it is possible to prevent toner from scattering from the developing unit or cleaning unit when the photoreceptor drum is opened, and it is possible to avoid toner contamination inside the machine. Good reliability can be maintained.

[Brief explanation of the drawing]

FIG. 1 is a schematic side sectional view showing the entire laser printer in one embodiment of the present invention, FIG. 2 is a sectional view taken along line I-I in FIG. 1, and FIG. 3 is an optical writing unit. FIGS. 4 and 5 are schematic side sectional views showing the operation of the device shown in FIG. 1; FIG. 6 is a schematic perspective view showing the structure of the paper guide opening/closing drive mechanism; FIG. It is. 1... Photosensitive drum, 3... Developing unit, 5...
・Cleaning unit, 30...Cover, 50...
・Opening portion, 51...paper guide, 52...rotation shaft,
53... Drive gear, 54... Rack gear, 55...
·coil spring. (1 person out)

Claims (1)

[Claims] An optical writing unit that forms an electrostatic latent image by optically writing on a photoreceptor drum with a light beam according to an image information signal.
A transfer section for transferring a toner image obtained by developing the electrostatic latent image onto a transfer paper is disposed at a position below the photoreceptor drum, and a transfer section for transferring a toner image obtained by developing the electrostatic latent image to a transfer paper is arranged above the photoreceptor drum. A developing unit that performs development and a cleaning unit that removes toner remaining on the photoreceptor drum after transfer are arranged to face both sides of the photoreceptor drum above the optical writing unit and below the transfer section. In the image forming apparatus, the transfer section and the photoreceptor drum are provided so as to be able to be opened and moved upwardly outside the machine, and as the transfer section and the photoreceptor drum are opened and moved, the development unit and the cleaning unit are moved. An image recording apparatus characterized in that a cover for preventing toner scattering is attached so as to close an opening formed between the two.