JP2889580B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus such as a laser beam printer and an electrophotographic copying machine, and more particularly to a power supply unit for supplying power to a process cartridge.

(Prior Art) In an image forming apparatus such as a laser beam printer or an electrophotographic copying machine, a photosensitive drum as an image carrier, a charger,
Process equipment such as a developing device and a cleaning device are integrated because long-term use of the device requires some maintenance such as cleaning, replenishment of consumables, or replacement due to life.
Many of the process cartridges are integrally detachable from the apparatus main body. It is necessary that a predetermined power be supplied to the process cartridge from the apparatus main body side.

FIG. 8 and FIG. 9 are diagrams showing a prior art relating to an arrangement state in a device main body such as a high-voltage power supply unit for supplying power from a device main body to a process cartridge in an image forming apparatus. In the figure, reference numeral 110 denotes a process cartridge, and the process cartridge 110 includes a photosensitive drum 1 serving as an image carrier.
A developing bias contact for applying a developing bias voltage to a developing sleeve 112a of the developing device 112 is provided on a lower surface of the process cartridge 110. 200 or charger 1
A high-voltage contact 201 and a grid contact 202 for applying a charging high voltage and a grid voltage to the 13 charging lines 113a and the shield 113b, respectively, are provided.

Although the process cartridge 110 is disposed substantially at the center of the apparatus main body 100, the axial direction of the photosensitive drum 111,
That is, a high voltage power supply unit 120 for applying an appropriate voltage to each of the contacts 200,... Of the process cartridge 110 and supplying power to the contacts 200,. On the lower surface of the high-voltage power supply unit 120, there are provided a developing bias output terminal 203, a high-voltage output terminal 204, and a grid output terminal 205 corresponding to the contacts 200,. Each of the contacts 200 to 202 of the process cartridge 110 and the high-voltage power supply unit 120
The connection unit 130 for electrically connecting the terminals 203 to 205 of the process cartridge 110 and the high-voltage power supply unit
The developing bias cable 131, the high-voltage cable 132, and the grid cable 13 are disposed below the
Each of the contacts 200,... Of the process cartridge 110 is electrically connected to each of the terminals 203,. Reference numeral 140 denotes a power input unit for supplying power to the high-voltage power supply unit 120.

(Problems to be Solved by the Invention) However, in the above-described conventional example, the voltage applied to the process cartridge 110 is generally very high, such as 500 to 1000 V, so that the insulation distance is set so that the wiring does not leak with other components. It was necessary to take measures such as securing them and inserting an insulating material between them. In addition, since the current value is as small as 50 to 100 mA, the contact resistance between the contacts must be minimized and conduction must be ensured.Use expensive materials with low contact resistance and make simultaneous contact at several places. Was configured to.

The present invention has been made to solve the above problems, and the object thereof is to simplify the electrical connection circuit between the process cartridge and the high-voltage power supply unit, to ensure the process cartridge and the high-voltage power supply unit, and An object of the present invention is to provide a small and compact image forming apparatus which can be easily electrically connected.

(Means for Solving the Problems) In an image forming apparatus for forming an image on a transfer material, an apparatus main body, a photosensitive drum, a charging member for charging the photosensitive drum, and a photosensitive member formed on the photosensitive drum A developing member for developing the latent image, and a cartridge mounting portion provided on the apparatus main body for detachably mounting a process cartridge detachably mounted on the apparatus main body; An opening / closing member that can be opened and closed with respect to the apparatus main body for mounting a process cartridge in the cartridge mounting portion; and a voltage for applying a voltage to the charging member and the developing member of the process cartridge mounted in the cartridge mounting portion. Power supply unit for detachably attaching the power supply unit to the apparatus main body from the side opposite to the side provided with the opening / closing member. A unit mounting portion, which is disposed on the back side of the cartridge mounting portion with respect to the opening / closing member, and is provided at a front end of the support member for guiding and sliding the power supply unit. A power supply unit mounting portion provided on the apparatus main body, the positioning portion having a positioning hole for engaging a guide pin of the power supply unit; and a front in a mounting direction when the process cartridge is mounted on the cartridge mounting portion. The charging member, and a cartridge electrical contact for receiving a voltage to be applied to the developing member provided from the power supply unit mounted on the power supply unit mounting portion, provided on the front end surface of the process cartridge located at The process cartridge mounted on the cartridge mounting portion when mounted on the power supply unit mounting portion The power supply unit provided on the surface of the power supply unit facing the cartridge electrical contact, the charging member of the process cartridge mounted on the cartridge mounting portion, and the developing member via the cartridge electrical contact. And a power supply unit electrical contact for applying a voltage from the power supply unit.

(Operation) According to the above configuration, power supply to the process cartridge can be performed directly from the power supply unit, and electrical connection between the process cartridge and the power supply unit can be reliably, easily, and quickly performed with a minimum number of components.

Further, since no relay member is required between the process cartridge and the power supply unit, the number of components can be reduced.

Further, the power supply unit is disposed inside the longitudinal end face of the process cartridge, and the power supply unit is detachably mounted to the apparatus main body in a direction substantially perpendicular to the longitudinal direction surface of the process cartridge. Of the cartridge in the longitudinal direction of the cartridge can be shortened, and an extra space available outside the cartridge in the longitudinal direction of the apparatus main body can be created.

(Embodiment) An embodiment of the present invention will be described below by taking a laser beam printer as an example of an image forming apparatus.

First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a side sectional view of a laser beam printer, FIG. 2 is a perspective view around a device main body of the laser beam printer, and FIG. 3 is a front sectional view around a process cartridge of the laser beam printer.

First, the configuration inside the laser beam printer will be described with reference to FIG. That is, in the drawing, reference numeral 1 denotes an apparatus main body, 10 denotes a process cartridge detachably mounted in the main body 1, and a photosensitive drum as an image carrier in the cartridge 10.
A well-known process device such as a charger 11, a developing device 13, and a cleaning device 14 disposed around the device 11 is built therein. Reference numeral 15 denotes a scanner unit that emits and scans laser light, and the charger 12 is a uniformly charged photosensitive drum.
The photosensitive drum 11 forms a latent image corresponding to desired printing (image) information by irradiating the laser beam L emitted from the unit 15 to the unit 11, and the latent image is developed by the developing unit 13.

16 is a cassette for storing the transfer paper P, 17 is the cassette
The transfer roller P feeds one sheet of transfer paper P from the transfer roller 16. The transfer paper P sent out by the feed roller 17 is synchronized with the rotation of the photosensitive drum 11 by the registration roller 18 and is directed toward the photosensitive drum 11. Conveyed. Reference numeral 19 denotes a transfer charger for transferring the developed image formed on the photosensitive drum 11 by the developing device 13 onto the transfer paper P, and reference numeral 20 denotes the transfer paper P on which the image transfer is performed by the transfer charger 19 to the fixing device 21. It is a conveyance belt unit for guiding.

In the above configuration, when a print start command is input from a computer, an image reader, or the like (not shown), a printing (image forming) operation is started, and the transfer paper P in the cassette 16 is fed to the apparatus by a feed roller 17 and a registration roller 18. The paper is conveyed from the upper left to the lower right in the figure in the main body 1 and passes between the photosensitive drum 11 and the transfer charger 19 and between the fixing devices 21 to print on the transfer paper P according to a known electrophotographic process. After that, the transfer paper P is discharged out of the apparatus.

In the apparatus shown in the drawing, there are provided two discharge methods. When the paper is discharged face-up, that is, with the print surface facing upward, the transfer paper P is directly discharged from the face discharge roller 22 to the first discharge tray. When the sheet is ejected face down, that is, ejected in the order of pages with the print side down, the transfer paper P is transferred from the face-up ejection roller 22 to the flapper 26 serving as a transfer sheet transport direction switching mechanism.
Is guided upward through the discharge roller for face down
The paper is discharged from 23 to the second paper discharge tray 25. 27 and 28 are transfer rollers for the transfer sheet P, and 29 is a manual feed port for the transfer sheet P.

Also, when performing maintenance of the apparatus, that is, when performing jam clearance of the transfer paper P or replacing the process cartridge 10, the first operation is performed.
As shown by the broken line in the figure, the front part 1a of the apparatus main body 1 on the side facing the operator rotates forward around the support shaft 30 to open the inside of the apparatus, and inserts a hand in the direction of arrow A in the figure. Work can be done.

2 and 3, the mounting state of the process cartridge 10 in the apparatus main body 1 will be described. The process cartridge 10 has a support shaft 10a on its left and right longitudinal end faces which are axial directions of the photosensitive drum 11. , 10a project, and the support shafts 10a, 1
0a is guided and supported in lateral grooves 31a, 31a of left and right cartridge holders 31, 31 fixed to the left and right side plates 1b, 1c of the apparatus main body 1, whereby the process cartridge 10 can be moved up and down, left and right, front and rear. And the lower part of the process cartridge 10 is supported by a cartridge table 32 fixed to the apparatus main body 1 to restrict the rotation of the process cartridge 10 about the support shafts 10a. Have been. Therefore, the process cartridge 10 is arranged such that the transfer surfaces extending in the left and right longitudinal directions are directed forward, and the longitudinal width is disposed entirely between the left and right plates 1b and 1c of the apparatus main body 1. Is detachable on the front side of the apparatus main body 1.

Next, power supply to the process cartridge 10 will be described with reference to FIGS. Process cartridge
On the back surface 10b side opposite to the transfer surface of 10, three contacts of a developing bias contact 40, a high voltage contact 41, and a grid contact 42 are vertically arranged. As shown in FIG. 1, the developing bias contact 40 is for applying a developing bias voltage to the developing sleeve 13a of the developing device 13, and the high voltage contact 41 is for applying a charging high voltage to the power interruption line 12a of the charger 12. The grid contact 42 is for applying a grid voltage to the shield 12b of the charger 12.

Behind the back surface 10b of the process cartridge 10 where the three contacts 40,... Are arranged, a predetermined voltage is applied to each of the contacts 40,. A power supply unit 50 is provided. The high-voltage power supply unit 50 is provided on the right side plate 1c of the apparatus main body 1.
It is mounted on a support plate 33 horizontally mounted in a direction substantially perpendicular to the back surface 10b of the process cartridge 10 at the lower part of the inner surface,
The upper and lower portions on the rear side are fixed to the right side plate 1c by screws 36,36. The upper part of the front surface 50a of the high-voltage power supply unit 50 is parallel to the rear surface 10b of the process cartridge 10 and is slightly inclined.
The developing bias contacts 4 are opposed to the three contacts 40,.
A developing bias output terminal 51 for zero, a high voltage output terminal 52 for high voltage contact 41, and a grid output terminal 53 for grid contact 42 are provided. The terminals 51,... Are formed of coil springs, and are electrically connected to the three contacts 40,.

A front end 33a of the support plate 33 is bent upward, and a positioning hole 34 for the high-voltage power supply unit 50 is provided in the front end 33a.
A guide pin 54 inserted into 34 is provided to protrude forward. The left side of the support plate 33 is also bent upward as shown in FIG. 2 to form a guide.

Thus, the high-voltage power supply unit 50 is located on the rear side of the main body 1.
That is, since the high-voltage power supply unit 50 can be attached to the apparatus main body 1 in the direction C in FIG. When the front surface 50a of the high-voltage power supply unit 50 is brought into contact with the front end 33a of the support plate 33 by sliding the guide on the support plate 33, the high-voltage power supply unit 50
Guide pin 54 and the positioning hole 34 of the support plate front end 33a are engaged, and the high-voltage power supply unit 50 is positioned, and the screws 36, 36
And is fixed to the apparatus main body 1 via. In this case, each terminal 51 of the high-voltage power supply unit 50 composed of a coil spring is provided.
Are pressed against the contacts 40,... Of the process cartridge 10,
The high-voltage power supply unit 50 and the process cartridge 10 are electrically connected directly. High-voltage power supply unit 50
Can be removed from the apparatus main body 1 in exactly the same procedure as in the case of the attachment.

As described above, the power supply to the process cartridge 10 can be directly performed by the high-voltage power supply unit 50 by inserting the high-voltage power supply unit 50 to the predetermined position of the apparatus main body 1, and the terminals 51, Are constituted by coil springs, the terminals 51,... And the contacts 40,... Are connected in a stable state even if the terminals 51,. Therefore, the process cartridge 10 and the high-voltage power supply unit 50 can be electrically connected reliably, easily, and quickly with a minimum number of components.

Also, the high-voltage power supply unit 50 is
1 The high-voltage power supply unit 50 is disposed inside the apparatus main body 1 from the outer surface, and the high-voltage power supply unit 50 can be attached and detached in a direction substantially orthogonal to the back surface 10b of the process cartridge 10. The distance between 1b and 1c can be minimized, and the apparatus body 1 can be made small and compact, and the space outside the left and right plates 1b and 1c can be used freely. The components of the drive system can be designed and arranged on the outside, and the electric boards of the control system can be designed and arranged outside of the right side plate 1c without considering the position and size of the high-voltage power supply unit 50. Therefore, an ideal image forming apparatus can be designed without increasing the width of the apparatus main body 1 in the longitudinal direction of the process cartridge 10. As described above, the main body 1 of the high-voltage power supply unit 50
It is easy to install and remove from
Maintenance is also improved.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a perspective view around the apparatus main body of the laser beam printer, and FIG. 5 is a view showing a state where the process cartridge is removed from the apparatus main body. When the components in the laser beam printer according to the present embodiment and the components in the laser beam printer according to the first embodiment have the same function, the components according to the present embodiment are related to the components according to the first embodiment. The same numbers are assigned to the constituent parts, and the description is omitted.

In the present embodiment, unlike the first embodiment, the high-voltage power supply unit 60
Can be attached to and detached from the apparatus main body 2 from the front side of the apparatus main body 2. That is, the support plate 330 that guides and supports the high-voltage power supply unit 60 and is attached to the right side plate 2c of the apparatus main body 2
The rear end 331 is bent upward, and a positioning hole 34 for the high-voltage power supply unit 60 is provided in the rear end 331. The high-voltage power supply unit 60 is fixed to the apparatus main body 2 by an L-shaped support fixed to a fixing plate 61 provided on the upper front surface of the high-voltage power supply unit 60 and the right side plate 2c of the apparatus main body 2. This is performed by fixing the plate 35 with screws or the like.

In order to remove the high-voltage power supply unit 60 from the apparatus main body 2, as shown in FIG. 5, the front part 2a of the apparatus main body 2 is pivoted forward to open, and the process cartridge 10 is opened to the left and right cartridges. After removal from the holders 31, 31, the engagement between the fixing plate 61 of the high-voltage power supply unit 60 and the L-shaped support plate 35 of the apparatus main body 2 is released, and the high-voltage power supply unit 60 is slid on the support plate 330, What is necessary is just to pull out the front which is a direction substantially orthogonal to the back surface 10b of the process cartridge 10.

The high-voltage power supply unit 60 may be mounted on the apparatus main body 2 by reversing the above-described procedure. The high-voltage power supply unit 60 is slid on the support plate 330 until the rear surface thereof contacts the rear end 331 of the support plate. When inserted into the apparatus main body 2, the rear end of the support plate
Guide pin 54 of high-voltage power supply unit 60 in positioning hole 34 of 331
Are engaged and the high-voltage power supply unit 60 is positioned, and then the fixing plate 61 of the high-voltage power supply unit 60 is fixed to the L-shaped support plate 35 on the device body 2 side.
Installation to the is completed.

Next, the supports 10a, 10a of the process cartridge 10 are engaged with the lateral grooves 31a, 31a of the cartridge holders 31, 31, and the process cartridge 10 is supported by the cartridge holders 31, 31. When the front end 2a of the apparatus main body is closed, the attachment of the process cartridge 10 to the apparatus main body 2 is completed.

By attaching the process cartridge 10 to the apparatus main body 2 as described above, three terminals of the high-voltage power supply unit 60 composed of a coil spring protrudingly provided on the back surface 10b side of the process cartridge 10, that is, a developing bias output terminal 51 and a high voltage output terminal 52 , Grid output terminal 53, process cartridge
It is electrically connected directly to three contacts provided on the back surface 10b side of 10, namely, a developing bias contact 40, a high voltage contact 41, and a grid contact 42.

As described above, in this embodiment, the process cartridge
Since the power supply to the high-voltage power supply unit 60 can be performed directly from the high-voltage power supply unit 60, the electrical connection between the process cartridge 10 and the high-voltage power supply unit 60 can be made reliably, easily, and quickly with a minimum number of necessary parts as in the first embodiment. The high-voltage power supply unit 60 is disposed inside the apparatus main body 2 from the outer surfaces of the cartridge holders 31 and 31.
60 can be mounted in a direction substantially perpendicular to the back surface 10b of the process cartridge, and can be mounted. Therefore, as in the first embodiment, the space outside the left and right plates 2b and 2c of the apparatus main body 2 can be freely set. The apparatus main body 2 can be made compact and compact, and an ideal image forming apparatus can be designed. Also, as described above, mounting the high-voltage power supply unit 60 to the device main body 2,
The ease of removal improves the ease of assembly and maintenance of the device.

Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a perspective view of a laser beam printer, and FIG.
The figure is a sectional side view of a laser beam printer. In the case where the component according to the present embodiment and the component according to the first embodiment have the same function, the component according to the present embodiment is given the same number as that of the component according to the first embodiment, and the description thereof will be made. Omitted.

The laser beam printer according to the present invention is of a type in which the transfer paper is moved horizontally, and as shown in FIG.
Below the process cartridge 10 in the apparatus main body 3, a cassette 16, a paper feed roller 17, a registration roller 18, a transfer charger 1
9, a conveyor belt unit 20, a fixing unit 21, and a face-up discharge roller 22 are provided. A face-down discharge roller 23 and a second discharge tray are provided above the process cartridge 10.
25 are located. The flapper and the first discharge tray are omitted in the figure. The back of the process cartridge 10
Above 10b, a high-voltage power supply unit 70 whose upper part is fixed to the apparatus main body 3 is disposed, and three contacts disposed on the back surface 10b of the process cartridge 10, namely, a developing bias contact 40,
The high-voltage contact 41, the grid contact 42, and three terminals formed of a coil spring disposed on the lower surface of the high-voltage power supply unit 70, that is, the developing bias output terminal 51, the high-voltage output terminal 52, and the grid output terminal 53 are in direct contact with each other in a pressed state. It is electrically connected in a stable state. The upper part of the high-voltage power supply unit 70 is covered with the power supply cover 36.

Thus, when removing the high-voltage power supply unit 70 from the apparatus main body 3, first remove the power supply cover 36 from the apparatus main body 3, then remove the screws 37, 37, and pull out the high-voltage power supply unit 70 upward. Power supply unit 70 to device body 3
, It may be performed in the reverse order. As described above, the high-voltage power supply unit 70 is attached to the apparatus main body 3 in a direction substantially orthogonal to the longitudinal back surface 10b which is the axial direction of the photosensitive drum 11 of the process cartridge 10, and is removed. The three terminals 51,... And the three contacts 40,... Of the process cartridge 10 can be securely, easily and quickly electrically connected with the minimum necessary parts, and the apparatus body 3 can be made small and compact. , Right side plate 3
The space outside b, 3c can be used effectively. Further, if a voltage adjustment volume (not shown) or the like is provided on the upper surface of the high-voltage power supply unit 70, the adjustment of the high-voltage power supply unit 70 can be easily performed only by removing the power supply cover 36.

In the first to third embodiments, the laser beam printer has been described. However, the present invention is not limited to this, and other screen forming apparatuses may be used as long as they include a process cartridge and a high-voltage power supply unit. It is.

As is apparent from the above description, according to the present embodiment, the power supply to the process cartridge is performed directly from the power supply unit, so that the electrical connection between the process cartridge and the power supply unit can be reliably, easily, and quickly performed with a minimum number of components. In addition, it is possible to eliminate the need for electric connection parts between the process cartridge and the power supply unit, so that it is possible to reduce the space and cost of the apparatus.

Further, the power supply unit is disposed inside both ends in the longitudinal direction of the process cartridge, and the power supply unit is detachably mounted to the apparatus main body in a direction substantially orthogonal to the longitudinal surface of the process cartridge. The space outside the longitudinal end face of the process cartridge can be effectively used, and the power supply unit can be attached to the apparatus body,
Removal becomes easy, and assemblability and maintainability of the device are improved. Further, the size of the apparatus main body with respect to the longitudinal direction of the process cartridge can be reduced, and the size and size of the apparatus main body can be reduced.

(Effects of the Invention) As described above, according to the present invention, the mounting direction of the power supply unit and the process cartridge is specified, and the power supply unit can be easily mounted at the correct position. In spite of making the power supply unit detachable, the cartridge electrical contact and the power supply unit electrical contact can be connected smoothly and reliably.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a laser beam printer according to a first embodiment, FIG. 2 is a perspective view around the apparatus main body of the laser beam printer, and FIG. 3 is a front sectional view around a process cartridge of the laser beam printer. FIG. 4 is a perspective view around the apparatus main body of the laser beam printer according to the second embodiment, and FIG.
FIG. 6 is a view showing a state where a process cartridge is removed from the apparatus main body of the laser beam printer. FIG. 6 is a perspective view of the laser beam printer according to the third embodiment. FIG. 7 is a side sectional view of the laser beam printer. FIG. 8 is a side sectional view around a process cartridge of an image forming apparatus according to the prior art, and FIG. 9 is a front sectional view around a process cartridge of the image forming apparatus. 1, 2, 3: Main body of the apparatus, 10: Process cartridge, 10b: Back surface of the process cartridge (longitudinal surface), 11: Photosensitive drum (image carrier), 50, 60, 70: High-voltage power supply unit (power supply unit).

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Ichiro Osawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-61-157225 (JP, A) JP-A-1 -140171 (JP, A) JP-A-62-234170 (JP, A) JP-A-63-360 (JP, U) JP-A-62-79248 (JP, U) JP-A-2-58750 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) G03G 15/00 556

Claims (1)

(57) [Claims] 1. An image forming apparatus for forming an image on a transfer material, comprising: an apparatus main body, a photosensitive drum, a charging member for charging the photosensitive drum, and a latent image formed on the photosensitive drum. A developing member for developing, for detachably mounting a process cartridge detachably mountable to the apparatus main body, a cartridge mounting section provided in the apparatus main body; and An opening / closing member that can be opened and closed with respect to the apparatus main body for mounting a process cartridge, the charging member included in the process cartridge mounted on the cartridge mounting portion, and a power supply unit for applying a voltage to the developing member. A power supply unit mounting portion for removably mounting from the side opposite to the side provided with the opening and closing member with respect to the apparatus main body; There is disposed on the back side of the cartridge mounting portion with respect to the opening and closing member,
The apparatus body further includes a support member for guiding and sliding the power supply unit, and a positioning hole provided at a front end of the support member for engaging a guide pin of the power supply unit. A power supply unit mounted on the power supply unit mounted on the front end surface of the process cartridge positioned forward in the mounting direction when the process cartridge is mounted on the cartridge mounting unit. From the unit the charging member, and
A cartridge electrical contact for receiving a voltage applied to the developing member, and facing the cartridge electrical contact of the process cartridge mounted on the cartridge mounting portion when the power supply unit is mounted on the power supply mounting portion. A power supply for applying a voltage from the power supply unit to the charging member of the process cartridge mounted on the cartridge mounting portion provided on the surface of the power supply unit and the developing member via the cartridge electrical contact; An image forming apparatus comprising: a unit electrical contact;