Electrophotography – Diagnostics – Consumable
Reexamination Certificate
2003-02-25
2004-10-12
Brase, Sandra L. (Department: 2852)
Electrophotography
Diagnostics
Consumable
C399S090000, C399S103000
Reexamination Certificate
active
06804476
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process cartridge detachably attachable to an image forming apparatus main body, a developing device, and image forming apparatus to which the process cartridge or the developing device is detachably attachable.
The term image forming apparatus here means one that forms an image on a recording medium using the electrophotography image forming process, and includes electrophotographic copying machines, electrophotographic printers (such as laser beam printers and LED printers), fax machines, word processors, etc.
A “process cartridge” refers to a cartridge obtained by integrating electrophotographic photosensitive drum with at least developing means so as to be detachably attachable to an image forming apparatus main body.
2. Related Background Art
Image forming apparatus using the electrophotography image forming process forms a latent image by irradiating an electrophotographic photosensitive member with light according to image information, visualizes an image from this latent image by supplying developing means with developer that is a recording material, and then forms the image on a recording medium by transferring the image from the electrophotographic photosensitive member onto the recording medium.
Such image forming apparatus employs a process cartridge method in which an electrophotographic photosensitive member and process means working over the electrophotographic photosensitive member are integrated to make a cartridge, or at least an electrophotographic photosensitive member and developing means are integrated to make a cartridge, and the cartridge is detachably attachable to an image forming apparatus main body. The process cartridge method allows a user to perform maintenance work of the apparatus by himself/herself, thereby improving the operability greatly. The process cartridge method is widely used in image forming apparatuses.
This type of process cartridge has a developing container for holding and receiving a developer carrying member that gives an electrophotographic photosensitive member developer, as well as a developer storing container for storing developer to be supplied to the developing container, and uses a developer seal member for separating the developing container and the developer storing container from each other in order to seal the developer in the developer storing container and prevent the developer from being sprayed until time of use. The developer seal member is structured such that it can be removed when the time comes to use the process cartridge. The developer seal member is pulled out of the cartridge before the process cartridge is attached to the image forming apparatus main body. This opens an opening portion of the developer storing container that stores developer to make the developer available to the developing container and the developer carrying member.
In image forming apparatus of process cartridge method, developer stored in a developer storing container inside a cartridge is consumed by forming an image. When the developer is spent, a user replaces the old process cartridge with new one to allow the apparatus to form an image again. Therefore it is necessary to notify, as the need arises, a user of how much of the developer remains in the cartridge and is available for image forming. In many cases, a process cartridge or image forming apparatus is provided with developer amount detecting means that can detect the remaining developer level consecutively in order to recommend a user to prepare a new cartridge and change properly and efficiently as the developer in the current cartridge is running out.
In the above-described process cartridge using a developer seal member which separates a developing container and a developer storing container from each other to seal developer in the developer storing container, the developer seal member must be pulled out of the cartridge upon the arrival of time of use. If, by mistake, the process cartridge is attached to the image forming device main body without pulling out the developer seal member, image output cannot be obtained because no developer is supplied to a developer carrying member and an electrophotographic photosensitive member when the image forming apparatus is turned on.
In order to avoid this situation, a measure disclosed in Japanese Patent Application Laid-Open No. 09-197945 has been proposed as means for detecting the presence or absence of a developer seal member. The means disclosed in this publication which detects the presence or absence of a developer seal member has, in a cartridge attachment portion of the apparatus main body, a light emitting portion and light receiving portion of a photointerrupter for detecting the presence or absence of a developer seal member in a process cartridge. In the case that the process cartridge is attached to the apparatus and main body and the developer seal member is not pulled out of the process cartridge, light from the light emitting portion is blocked by the developer seal member and does not reach the light receiving portion. A detecting circuit connected to the photointerrupter of the apparatus main body thus detects that the developer seal member is not pulled out. Further, based on the detection result, the fact that the developer seal member has not been pulled out is displayed in, for example, a display unit of the apparatus main body to notify a user of the fact.
However, the detecting means disclosed in the publication needs to provide the apparatus main body with the photointerrupter having the light emitting portion and the light receiving portion and with the detecting circuit of the photointerrupter. This addition of parts and circuits makes the structure expensive.
Another method is to affix a projecting member at an end (an end in the pulling-out direction) of a developer seal member to physically prevent a process cartridge from entering image forming apparatus main body unless the developer seal member is pulled out. However, this method requires a fairly large projecting member in order to make sure that the process cartridge cannot enter the image forming apparatus main body.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a developing device, process cartridge, and image forming apparatus capable of detecting, without fail, a developer seal member which is removably attached to a developer storing container to block a supplying opening portion and seal developer in the developer storing container and which should be pulled out to open the supplying opening portion and make the developer available to a developing member but is accidentally left in place without being pulled out.
Another object of the present invention is to provide a developing device, process cartridge, and image forming apparatus capable of detecting, without fail, with no need for dedicated detecting means, a developer seal member which is removably attached to a developer storing container to block a supplying opening portion and seal developer in the developer storing container and which should be pulled out to open the supplying opening portion and make the developer available to a developing member but is accidentally left in place without being pulled out.
Further, another object of the present invention is to provide a developing device, process cartridge, and image forming apparatus which do not start image forming operations when the developing device or the process cartridge is attached to the image forming apparatus main body without removing a developer seal member.
Still further, another object of the present invention is to provide a developing device, process cartridge, and image forming apparatus capable of detecting a developer seal member which is accidentally left without being pulled out when the developing device or the process cartridge is attached to the image forming apparatus main body without removing the developer seal member.
Yet further, another object of the present invention is to provi
Mochizuki Masataka
Oguma Toru
Yokoi Akiyoshi
Brase Sandra L.
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
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