JPS61156070A - Picture formation device - Google Patents

Abstract

PURPOSE:To load/unload easily an image carrier and a latent image forming head holding a precise gap by holding unitedly the latent image forming head and the image carrier while keeping a prescribed gap between the head and the carrier to constitute an image formation unit, and fitting the unit to a device body attachably/detachably. CONSTITUTION:The image formation unit 3 is constituted by holding a dielectric drum 4 unitedly with an ion head 5 forming an electrostatic latent image on the drum 4 and fitted to a lower body 1b attachably/datachably. The image formation unit 3 is provided with two drum supporting plates 22, 22' supporting the shaft 4' of the drum 4 through a bearing 21 and a supporting frame body 24 consisting of upper stays 23-1, 23-2 and lower stays 23-3, 23-4 connecting and fixing both the supporting plates 22, 22'. The ion head 5 is arranged on an opening part between the upper stays 23-1 and 23-2 and positioning hole parts 25, 25' formed on the fitting part of the ion head 5 are engaged with projection parts 26, 26' formed on the upper end surface of the supporting plates 22, 22' and screwed, so that the ion head 5 is held unitedly wit the dielectric drum 4 while keeping a prescribed fine gap with the surface of the drum 4.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to image formation using a gutter to form a latent image [Prior art] Generally, an electronic image forming apparatus forms an electrostatic latent image on an image carrier. , an image is obtained by developing the latent image with toner, and various methods have been proposed for forming the latent image.

One method of forming an electrostatic latent image in such an image forming apparatus is to generate ions using discharge, extract the ions, and form a latent image on an image carrier having a dielectric surface. For example, it is shown in Japanese Patent Publication No. 57-501348.

This method applies high-frequency alternating current between two electrodes separated by a dielectric member to generate a discharge, and uses an ion head that extracts ions generated by the discharge according to an image signal. A latent image is formed on an image carrier such as a body drum.

Incidentally, the ion head used in this method is arranged with a minute gap of, for example, about 0.31 mm relative to the dielectric drum, but in the past, the ion head and the ion head were placed separately in the main body of the device. Configured to be installed. Therefore, when assembling or performing periodic inspections or replacements, not only must the dielectric drum and ion head be installed or removed using separate mounting means and in separate operations, but the dielectric The ion head must be mounted on the drum through a predetermined minute gap, and the mounting operation is difficult and extremely complicated. Similar problems also occur in image forming apparatuses that use a liquid crystal head, a CCD head, or the like as a latent image forming head.

[Purpose of the invention]

The present invention has been made in order to solve the drawbacks and problems of conventional image forming apparatuses using latent image forming heads. It is an object of the present invention to provide an image forming apparatus that can be easily attached to a main body.

[1 Summary of the Invention] The present invention constitutes an image forming unit by integrally holding a latent image forming head with a predetermined gap with respect to an image carrier such as a drum, and attaching the unit to an apparatus main body. Attaches removably,
This is intended to facilitate the operation of attaching and detaching the image carrier and the latent image forming head while maintaining a precise gap.

〔Example〕

Embodiments of the present invention will be described below.6 Figure 1 is a schematic cross-sectional diagram showing a part of an embodiment in which the present invention is applied to an image forming apparatus using an ion head. is a partially exploded perspective view of the image forming unit, FIG.
is its cross-sectional view, and FIG. 2 (0 is its rear view).

In the figure, 1 is the main body of the device, an upper main body 1a and a lower main body 1.
b, and the upper main body 1a can rotate in the direction of the arrow with respect to the lower main body 1b around the rotation axis 2 to form an opening. 3 is a dielectric drum 4
This is an image forming unit that integrally holds an ion head 5 for forming an electrostatic latent image on the dielectric drum 4, and is removably attached to the lower main body 1b. 6 is the upper body 1
1 at the power feeding part to the node 5 to the ions attached to a.
When the upper body 1a is placed on the lower body 1b and the opening is closed, power is supplied to the ion head 5 through the pin 6'.

7 is a developing device for toner development of the electrostatic latent image formed on the dielectric drum 4; 8 is a transfer corona charger disposed below the dielectric drum 4; The toner image formed on the dielectric drum 4 is transferred onto the paper fed from the paper cassette 7) 10 via the paper cassette 7). Reference numeral 11 denotes a conveyance device that conveys the paper onto which the toner image has been transferred to the fixing device 12, and 13 denotes a paper receiver for receiving the fixed paper. 14 is a cleaning device for removing toner remaining on the electric drum 4 after transfer.

As shown in FIG. 2, the image forming unit 3 includes two drum support plates 22 and 22', each supporting the shaft 4' of the drum 4 via a bearing 21, and 23-2. 1
．． 23-z and lower stays 23-, 23-, and an upper stay 23-z. ,,
.

The ion nozzle 5 is arranged in the opening between 23-2, and the positioning hole 25° 25' formed in the mounting part thereof.
is fitted into the protrusion 26.26' formed on the upper end surface of the support plate 22.22', and is held integrally with the surface of the dielectric drum 4 by keeping a predetermined minute gap with the surface of the dielectric drum 4 by screwing it. It is now possible to do so. Also, upper stay 23-
1.23-z and the lower stay 23-3. A part of the dielectric drum 4 supported between the support plates 22° and 22' protrudes from each opening between the lower stay 23-3 and 23-4. Further, the transfer corona charger 8 is inserted into the opening between the lower stays 23-z and 23-4 when the image forming unit 3 is attached to the lower main body 1b.

Further, a positioning groove 27 is formed in the lower central portion of the support plate 22, 22', and tapered positioning projections 28 are formed in the upper portions of both sides. When the image forming unit 3 is placed in the lower main body 1, the image forming unit 3 shown in FIG. 2 (
As shown in C1, the V groove 27 fits into the chevron-shaped protrusion 30 formed on the support member 29, and the tapered protrusion 28 engages with the tapered notch 31 also formed on the support member 29. and is designed to be accurately positioned and held.

Further, as shown in FIG. 2(B), the upper stays 23-, 23- forming the support frame 24 of the image forming unit 3 have a surface facing the dielectric drum 4 of, for example, 0.1 ~0
．． The upper stay 23 is formed along the surface of the drum while maintaining a minute gap of about 5 mm, and the toner scattered from the developing device 7 or the cleaning device 14 is transferred to the ions in the upper stay 23. It has a toner shield function to prevent it from entering between 23-2. On the other hand, a guide curved surface portion is formed on the surface of the lower stay 23-3, 23- that faces the dielectric drum 4, and is used to feed paper to the transfer section below the drum 4 and to guide paper from the transfer section, respectively. It has a paper feeding guide function.

Note that 32 is a drum driving gear fixed to one end of the shaft 4' of the dielectric drum 4.

As shown in FIG. 3, the developing device 7 has a rotation support shaft 7', and the development device 7 is rotated in the direction of the arrow around the rotation support shaft 7'. A spring 33 is provided to urge the body drum 4 to be sufficiently separated from the body drum 4. Furthermore, a positioning member 34 having an oblong hole 34' is formed in the developing device 7, and a positioning member 34 provided in the oblong hole 34' of the positioning member 34 is provided at a predetermined position of the upper body 1a. A tapered positioning pin 35 is fitted when the upper main body 1a is closed, and the developing device 7 is rotated in the direction opposite to the arrow direction by the taper of the positioning pin 35 against the spring 33. body drum 4
The configuration is such that they face each other at a predetermined interval.

Similarly to the developing device 7, the cleaning device 14 also has a rotating shaft 14', and the cleaning device 4 is rotated in the direction of the arrow around the rotating shaft 14', as shown in FIG. A spring 36 is provided for moving the cleaning device 14 and biasing the cleaning device 14 to a sufficient distance from the dielectric drum 4. The cleaning device 14 is further provided with a positioning member 37 having an oblong hole 37'. A tapered positioning pin 38 provided at a predetermined position of the upper body 1a is fitted into the oval hole 37' of the positioning member 37 when the upper body 1a is closed, and the cleaning device 14 is rotated in a direction opposite to the arrow direction by the taper of the positioning pin 38 against the spring 36, and brought into contact with the dielectric drum 4 at a predetermined position.

In FIG. 1, reference numerals 39 and 40 indicate stoppers for limiting the range of rotation of the developing device 7 and the cleaning device 14 by the springs 33.degree. 36, respectively. Also, the diameter of each positioning pin 35.38 and the pin 35.38
The size of each oval hole 34', 37' into which the developer is inserted is appropriately set according to the desired movement amount of the developing device 7 and the cleaning device 14.

As described above, the image forming unit 3, in which the dielectric drum 4 and the ion head 5 are integrally held with a predetermined gap by the support frame 24, is mounted on the main body 1 of the apparatus and is inverted, and the main body of the apparatus is opened. The power supply unit 6 attached to the main body la is moved from a predetermined position. At this time, upper body 1
In conjunction with the opening operation of a, the respective oval holes 34' of the positioning members 34 and 37 of the developing device 7 and the cleaning device 14 are opened.
, 37' are removed, and the developing device 7 and cleaning device 14 are removed.
are rotated in the direction of the arrow by springs 33 and 36 until they abut against stopper pins 39 and 40, respectively, and enter the retracted state.

In this state, the support plate 22.2 of the image forming unit 3
2' is dropped along the unit support member 29 provided on the lower main body 1b, since the developing device 7 and the cleaning device have been retracted, the developing device 7 and the cleaning device are placed on the dielectric drum 4 of the image forming unit 3. 14 does not come into contact with each other and can be easily inserted without causing any hindrance. Then, the V groove 27 formed on the unit support plate 22, 22' is replaced by the chevron-shaped protrusion 30 formed on the support member 29.
The image forming unit 3 can be accurately mounted in a predetermined position by fitting the image forming unit 3 into the tapered notch 31 of the groove 29. Next, by rotating the upper body 1a and closing the device body 1, the power supply unit 6 is connected to the pin 6.
' to enable connection to the ion head 5 of the image forming unit 3 to start power supply, and positioning pins 35 and 38 for the developing device 7 and cleaning device 14 provided on the upper body 1a, respectively. The positioning members 34.37 of the developing device 7 and the cleaning device 14 are inserted into the oblong holes 34', 37', and the positioning pins 35.
The developing device 7 and the cleaning device I4 are rotated by an amount of 38 tapers against the springs 33 and 36 to be placed in a predetermined position and ready for use.

When the image forming unit 3 is removed for maintenance inspection or replacement at the end of its life, the above mounting operation points may be reversed. That is, first, the upper body 1a is opened and the power supply unit 6 is moved, and in conjunction with the opening operation of the upper body 1a, the positioning pin 35.38 is pulled out from the positioning member 34.37, and the spring 33.36 is pulled out. The developing device 7 and the cleaning device 14 are rotated in the direction of the arrow. As a result, the developing device 7 and the cleaning device 14 are separated from the dielectric drum 4 of the image forming unit 3. Therefore, the developing device 7 and the cleaning device 14 are separated from the dielectric drum 4 of the image forming unit 3.
can be pulled upward from the support member 29 and removed.

In the above embodiment, the image forming unit is installed in the main body of the apparatus by dropping it from above.
The image forming unit can also be configured to be inserted by being pushed in from the side of the apparatus main body. In this case, go to Figure 4~
(As shown in C1, the support 1i22 of the image forming unit 3
．． Protrusions 41 are provided on the upper sides of both sides of 22', and grooves 43 for guiding the protrusions 41 are provided on the unit support member 42 on the main body side.
Form it. When the image forming unit 3 is installed from the side, the projection 41 of the unit 3 is inserted into the groove 43 while being guided, and the positioning pin 44' provided on the surface of the support plate 22' at the front in the insertion direction is inserted into the main body. A positioning hole 45 is inserted into a positioning hole (not shown) provided on the side, and a positioning pin 44 provided on the surface of the rear support plate 22 is inserted into a positioning hole 45 provided in a positioning end plate 45 that is separately attached or fixed to the main body of the device. ′
, and position the image forming unit 3.

Note that when the image forming unit 3 is installed by being pushed in from the side of the apparatus main body as described above, in order to pass the transfer charger 8 disposed below the unit 3, the image forming unit 3 shown in FIG.
As shown in +, it is necessary to form a notch 46 in the front support plate 22'.

However, the transfer charger 8 may be configured to be moved downward when the image forming unit 3 is attached, and returned to a predetermined position after the image forming unit 3 is attached. In this case, as shown in FIG. 4 (Bl), the lower stay 23-3.2 of the unit 3
A notch 21 for positioning the charger 8 is provided at the inner lower end of 3-.
By providing ', 2L,', the positioning of the charger 8 can be easily performed.

Also, when the bE image forming unit 3 is attached from the side as described above, the power supply section 6. Developing device7. It is necessary to clear it. To deal with this, the power supply section 6 is made movable in conjunction with the opening operation of the upper main body 1a, as in the previous embodiment.
Further, as in the previous embodiment, the developing device 7 and the cleaning device 14 are provided with springs so that they can rotate and retreat, and the developing device W7 and the cleaning device 14 are provided with positioning holes (not shown). A taper pin 47 provided on the positioning end plate 45 is provided in the cough hole.
By inserting and removing ゜48, the developing device 7 and cleaning device 14 are installed.
The image forming unit 3 can be retracted from the image forming unit 3 or placed at a predetermined position.

FIG. 5 is a partial cross-sectional schematic diagram of a second embodiment of the present invention, in which the same members as in the first embodiment are designated by the same reference numerals. The image forming unit 51 in this embodiment is constructed by integrally incorporating a developing device and a cleaning device in addition to a dielectric drum and an ion head. That is,
As shown in FIG. 6 (8) to (C1), the image forming unit 5
1 is a drum chamber 52-, in which a dielectric drum is arranged;
A developing chamber 52-3 in which the ion nozzle is placed;
Cleaning chamber 52 where cleaning blades etc. are arranged
-4 is provided with a unit frame 53 integrally formed. In the drum chamber 52-1, a part of the dielectric drum 4 is exposed to the other chambers 52-2+ 52-i+ 52-4, and further through an opening 54 provided at the lower part of the frame 53. It is arranged so as to protrude, and its rotation axis is located at both sides 53- + of the unit frame 53.

53-2, and one shaft end has a side portion 53-2.
A drive gear 55 provided on the outside of 2 is fixed. The ion head 5 is placed in the head placement chamber 52-2.
The positioning holes 25, 25' are engaged with positioning pins 26, 26' provided on the upper surface of the unit frame 53, and the unit frame 53 is fixed with screws so as to maintain a predetermined minute gap with the dielectric drum 4. A developing roller 56 is disposed in the developing chamber 52-3 so as to face the dielectric drum 4 at a predetermined distance, and its rotation axis is connected to both sides 53- of the unit frame 53.
．． ．． 53-z, and one shaft end has a side part 5.
A drive gear 57 provided on the outside of the drive gear 3 is fixed. Further, a cleaning blade 58 is arranged in the cleaning chamber 52-4 so as to be in contact with the surface of the dielectric drum 4.

Note that 59 is a lid of a toner filling hole in the developing chamber 52-3.

The image forming unit 51 configured in this manner can be configured to be installed by being dropped from above the apparatus main body, or can be configured to be installed by being pushed in from the side, as in the first embodiment. You can also do that.

In this embodiment, not only the dielectric drum and ion head but also the developing device and the cleaning device are integrated into a unit, so the distance between the dielectric drum and ion head and the distance between the dielectric drum and developing roller can be adjusted. Settings can be made with high precision, making operations easier during assembly and replacement.

In each of the above embodiments, an image forming apparatus using an ion head has been described, but the present invention is not limited to this. Of course, the present invention can also be applied to an image forming apparatus using a liquid crystal head or a CCD head, and similar effects can be obtained.

〔Effect of the invention〕

As described above in detail based on the embodiments, according to the present invention, in an image forming apparatus, a latent image forming head is integrally held with a predetermined gap with respect to an image carrier such as a drum, and an image is formed. Since the forming unit is configured and detachably attached to the main body of the apparatus, the image bearing member and the latent image forming head can be easily operated while maintaining a predetermined gap between them with high precision. It can be easily attached to the main body of the device, and it can also be easily removed and replaced.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional schematic diagram of a first embodiment of the image forming apparatus according to the present invention, the second diagram is a perspective view of the image forming unit, and FIG. Figure 2 (C1 is
The back view, FIG. 3, is a diagram showing the developing device and cleaning device separated from the dielectric drum, and FIG.
(81, (C) is a second diagram. (Bl, (C) A perspective view of a modified example of the image forming unit shown in (C1. Fig. 6(C) is the back view of Fig. 6(C).
) is its cross-sectional view. In the figure, ■ is the main body of the apparatus, 3 is an image forming unit, 4 is a dielectric drum, 5 is an ion head, 6 is a power supply unit, 7 is a developing device, 8 is a transfer corona charger, 10 is a paper cassette, and 12 is a Fixing W position, 14 is cleaning device, 22.2
2' is a support plate, 23-, 23-2 is an upper stay, 2
3-3.23- is the lower stay, 24 is the support. Frame body, 25.25' is a positioning hole, 27 is a positioning groove, 28 is a positioning projection, 29 is a support member, 30 is a chevron-shaped projection, 31 is a tapered notch, 32 is a drum drive gear, 33.36 is a spring, 34.37 is a positioning member, 35.38 is a positioning pin, 41 is a protrusion, 4
2 is a support member, 43 is a guide groove, 44.44' is a positioning pin, 45 is a positioning end plate, 46 is a notch, 47.
48 is a Cheever pin, 51 is an image forming unit, 53 is a unit frame, 55, 57 is a driving gear, 5G is a developing roller, 58 is a cleaning blade, and 59 is a lid. Patent applicant: Olympus Optical Industry Co., Ltd. lem people! ! ＋! ') ) - (i
l 1 unit, -1 Fig. 1 Fig. 3 +81 +C1 Fig. 5

Claims (2)

[Claims] (1) In an image forming apparatus that forms an electrostatic latent image on an image carrier such as a drum by a latent image forming head and develops the latent image to form an image, a predetermined gap is provided between the image carrier and the image carrier. An image forming apparatus characterized in that the latent image forming head is integrally arranged to form an image forming unit, and the unit is removably attached to an apparatus main body. (2) The image forming unit further integrally holds a developing means for developing the electrostatic latent image formed on the image bearing member, and a cleaning means for removing residual developer on the image bearing member. An image forming apparatus according to claim 1, characterized in that: