Exemplary embodiments of the present invention will be described in detail based on the following figures, wherein:
First, an outline of an image forming apparatus 10 according to the present invention will be explained.
<Basic Configuration>
As shown in
Each of the developing units 16 includes a charging roller 22 (22K, 22C, 22M, 22Y) for uniformly charging a surface of the roll-like image carrier 20, an optical box 24 which irradiates the image carrier 20 with image light based on image data to form a latent image by a difference of electrostatic potentials, a developing roller 26 (26K, 26C, 26M, 26Y) which selectively feeds toner to the latent image to make it visible, and a cleaning member 28 which comes into slide contact with the image carrier 20 after the toner image is transferred to clean the toner remaining on the image carrier 20.
The image carrier 20 is provided on its surface (peripheral surface) with a photoreceptor layer. After the surface (peripheral surface) of the image carrier 20 is uniformly charged by the charging roller 22, the surface (peripheral surface) is exposed to laser light (image light) emitted from the optical box 24, the potential of the exposed portion is attenuated, thereby forming an electrostatic latent image (image). The charging roller 22 abuts against the image carrier 20, voltage is applied to therebetween, electricity is discharged in a fine gap near the abutment portion, and thereby the surface of the image carrier 20 is substantially uniformly charged.
The optical box 24 allows flashing laser light to scan a surface (peripheral surface) of the image carrier 20 to form an electrostatic latent image on the surface (peripheral surface) of the image carrier 20 based on the image data. As the optical box 24, luminous elements such as LEDs may be arranged and they are allowed to flash based on the image data.
The developing roller 26 is disposed close to the image carrier 20 such as to be opposed thereto, and developing bias voltage is applied between the developing roller 26 and the image carrier 20. With this, a developing bias electric field is formed between the developing roller 26 and the image carrier 20, and toner having electric charge is transferred to the exposed portion on the image carrier 20 to form a visible image.
The feeding unit 18 includes a feeding belt 34 which is wound around at least a driving roller 30 and a following roller 32. A plurality of (four corresponding to later-described colors) transferring rollers 36 (36K, 36C, 36M, 36Y) are disposed at predetermined distances from one another at predetermined positions between the driving roller 30 and the following roller 32 on inner side of the feeding belt 34.
When the cover body 14 is closed (when the cover body 14 is turned toward the body frame 12 to close the image carrier 20 and the like), the transferring roller 36 is opposed to the image carrier 20 across the feeding belt 34. By forming a transfer electric field between the image carrier 20 and the transferring roller 36, a toner image (non-fixed image) on the surface of the image carrier 20 is transferred onto the recording sheet P which is sucked and fed by the feeding belt 34.
Here, the developing units 16 are disposed in the vertical direction in the order of yellow (Y), magenta (M), cyan (C), black (K) along the feeding direction of the recording sheet P from below so that full color printing can be carried out, and a fixing apparatus 38 is disposed downstream of the developing units 16Y to 16 K in the feeding direction of the recording sheet P.
The developing units 16Y to 16K develop electrostatic images on the image carriers 20Y to 20K with toner of yellow (Y), magenta (M), cyan (C), black (K), and then transfers the formed toner image on the recording sheet P.
Since toner Ty to Tk in the developing units 16Y to 16K are consumed by forming toner image, the processing is carried out while maintaining the amount of toner of each colors in the developing units 16Y to 16K by filling toner from the toner cartridges 17Y to 17K suitably.
The fixing apparatus 38 includes a heating roller 40 and a pressing roller 42 whose peripheral surfaces are opposed to each other and which are nipped under predetermined pressure. The heating roller 40 and the pressing roller 42 heat and press a pre-fixed toner image transferred onto the recording sheet P, thereby fixing the toner image on the recording sheet P.
The recording sheet P with the toner image fixed by heating and pressing by the fixing apparatus 38 (heating roller 40 and the pressing roller 42) is discharged on an output tray 44. After the toner image is transferred to the recording sheet P, a surface (peripheral surface) of the image carrier 20 is cleaned by the cleaning member 28 to prepare for a next image forming process.
The body frame 12 is provided at its lower portion with a detachable paper cassette 46. The paper cassette 46 can be pulled out in a direction opposite to a direction where the recording sheet P is sent out, in order to supply recording sheets P suitably.
A pair of paper feeding rollers 48 which sends out recording sheets P one-sheet by one-sheet from the paper cassette 46 is provided in the vicinity of a tip end of the paper cassette 46. The recording sheet P sent out from the pair of paper feeding rollers 48 is sent out to a suction feeding surface of the feeding belt 34 at predetermined timing by a pair of resist rollers 49, and is fed to a transfer position of each toner image of the corresponding color.
In the image forming apparatus 10 of the above-described configuration, the feeding unit 18 detachably mounted on the cover body 14 will be explained in more detail.
The feeding unit 18 includes a substantially rectangular frame-like casing 50. The driving roller 30 is rotatably supported on one end (upper end) of the casing 50, and the following roller 32 is rotatably supported on the other end (lower end). The transfer belt 34 capable of sucking the recording sheet P with electrostatic is wound around the driving roller 30 and the following roller 32.
The transferring rollers 36Y to 36K for each of the colors are disposed at predetermined distances from one another between the driving roller 30 and the following roller 32 on the inner side of the transfer belt 34. The transferring rollers 36Y to 36K are also rotatably supported by the casing 50. When the cover body 14 is closed, the transferring rollers 36Y to 36K nip the image carriers 20Y to 20K under a predetermined pressure, sandwiching the transfer belt 34 to rotate following the running of the transfer belt 34.
<Toner Cartridge>
The toner cartridge 17 of the present invention includes three blocks, i.e., a central portion 74, and projections 76A and 76B as shown in
The central portion 74 is a space for containing toner T therein. The capacity of the central portion 74 is reduced for toner whose consuming amount is small as shown in
As shown in
As shown in
As shown in
The agitator 80 which feeds the toner T is driven by external power through a gear 90. The agitator 80 feeds toner T which is dropped into the inner housing 72 from the opening 72A in a direction shown with a white arrow in the figure, and supplies the toner T from the toner supply opening 73 to the apparatus main body.
The opening 72A is provided with at least one bridging portion 71 in the longitudinal direction. The bridging portion 71 maintains the strength of the opening 72A. The bridging portion 71 has a substantially triangular cross section, and base portions of both ends are thickened in a form of taper and connected to the inner housing 72.
An end 71b of the bridging portion 71 is tapered, and connected to the inner housing 72. Therefore, the twisting strength of the bridging portion 71 itself can be enhanced, and is consequently effective for enhancing twisting strength of the inner housing 72 itself.
Since the cross section of the bridging portion 71 is triangular in shape, toner is not deposited on the bridging portion 71 easily, the amount of remaining toner when the use of the toner cartridge 17 is completed can be reduced.
To prevent the inside toner from leaking out at the time of transfer, the inner housing 72 is inserted into the toner cartridge 17 such that the toner supply opening 73 of the inner housing 72 and the toner supply opening 84 of the outer housing 70 are not superposed on each other.
According to the toner cartridge 17 of the present invention, before it is attached, the toner supply opening 73 provided on the inner housing 72 is deviated from the toner supply opening 84 provided in the outer housing 70 and the toner supply opening 73 and the toner supply opening 84 are not in communication with each other. Thus, toner in the central portion 74 of the outer housing 70 does not leak out. The toner supply opening 84 is provided at its both sides with seal members 86, to prevent toner from leaking.
When the toner cartridge 17 is attached to the apparatus main body and toner therein is supplied to the apparatus main body, first, the inner housing 72 is turned in the clockwise direction in the figure by twisting a handle 92 as shown in
Next, the toner cartridge 17 is attached to the apparatus main body and then, the heat seal 88 provided on the inner housing 72 is pulled out. With this, the heat seal 88 which has sealed between the toner supply openings 73 and 84 is discharged out from the toner cartridge 17, the toner supply openings 73 and 84 are brought into communication with each other, and the inside toner T is supplied to the apparatus main body from the toner supply openings 73 and 84.
At that time, since the opening 72A is provided vicinity of substantial center in the longitudinal direction of the inner housing 72 and a cross-sectional area of its portion corresponding to the central portion 74 becomes smaller as compared with the both ends, there has been a problem that when the handle 92 is twisted, the twisting strength near the center of the inner housing 72 cannot be maintained.
According to the present invention, the bridging portion 71 is provided in the opening 72A of the inner housing 72. With this it is possible to suppress the deterioration in twisting strength at the time or rotational operation, and to prevent the rotational load from increasing. Therefore, even when the rotational operation handle 92, on the opposite side of the portion near the toner supply opening 73 which receives a rotational resistance by the seal member 86, is held and operated, the rotational load is not increased, and then the operability with one hand can be secured.
A lower portion of the central portion 74 of the outer housing 70 is formed to have a semi-circular cross section shape that is the same shape as lower ends of the projections 76A and 76B. Therefore, when the inside toner is consumed, transport of the inside toner in the longitudinal direction is not hindered, and unnecessary toner residue (increase in residual amount) can be avoided.
<Angle of Opening>
According to the toner cartridge 17 of the invention, as shown in
With this, a case where toner is deposited between the inner housing 72 and the inner wall of the outer housing 70 and is not discharged out can be avoided. That is, when the opening width of the opening 72A is not wide enough, toner T is deposited between the inner housing 72 and the inner wall of the outer housing 70 as shown in
Whereas, in this embodiment, since the opening angle of the opening 72A is about 180° as shown in
Further, as shown in
The height of the bridging portion 71 in the radial direction (vertical direction in the figure), i.e., the thickness is set to equal to or smaller than the thickness of the inner housing 72 itself.
That is, if the triangular inclination angle 01 which is a cross section of the bridging portion 71 shown in
<Position of the Bridging Portion>
When toner is filled into the toner cartridge 17, toner is filled from a side of the opening (toner filling opening: e.g., 79) formed at the end of the projection 76A and then, it is fixed and sealed using a cap (e.g., 96) (see
On the other hand, in the toner supply position where toner is supplied from the toner cartridge 17 to the apparatus main body as shown in
A V-shaped seal member 82 is provided at a predetermined location (shown in
The toner cartridge 17 of the present invention prevents toner from leaking and sealed by the V-shaped seal member 82 provided between the outer housing 70 and the inner housing 72. Therefore, to enhance the sealing ability, the nipping pressure (abutting pressure) of the V-shaped seal member 82 provided on the inner housing 72 against the outer housing 70 should be increased.
However, if the nipping pressure of the V-shaped seal member 82 is increased, the rotational operation force when the inner housing 72 is attached and detached is increased. That is, there is a drawback in that it becomes heavy when the handle 92 is operated. Thus, it is preferable that the set value of the nipping pressure of the V-shaped seal member 82 is increased within a range in which the operability does not deteriorate, so that the sealing ability is secured.
A graph shown in
The present invention is not limited to the above exemplary embodiment.
For example, although the toner cartridge is for electrophotography in the exemplary embodiment, the invention is not limited to this, and the invention can be applied to other type product as long as fine powder is fed out from a storing container.
The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The exemplary embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.
Number | Date | Country | Kind |
---|---|---|---|
2006-123926 | Apr 2006 | JP | national |