Process cartridge and image forming apparatus

Electrophotography – Diagnostics – Component present or mounted

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C399S027000

Reexamination Certificate

active

06408142

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process cartridge and an image forming apparatus containing such a cartridge. The image forming apparatus may be, for example, a laser beam printer, an electrophotographic copying machine, a facsimile machine, a word processor or the like.
2. Related Background Art
In image forming apparatuses such as printers, a latent image is formed by selectively exposing a photosensitive drum (an image bearing member) which has been uniformly charged, and the latent image is then visualized with toner as a toner image which is in turn transferred onto a recording sheet, thereby recording an image on the recording sheet. In such apparatuses, whenever the toner is consumed or used up, new toner must be replenished. However, the toner replenishing operation not only is troublesome, but also often causes contamination of surrounding components. Further, maintenance of various elements must be performed periodically.
To this end, a so-called process cartridge wherein a photosensitive drum, a charger, a developing device, a cleaning device and the like are integrally contained in a cartridge housing which can be removably mounted to an image forming apparatus, whereby the replenishment of toner or the exchange of parts whose service lives have expired can be permitted and maintenance can be facilitated, has been proposed and put into practical use (for example, as disclosed in U.S. Pat. Nos. 3,985,436, 4,500,195, 4,540,268 and 4,627,701).
Since such a process cartridge is mounted to and dismounted from the image forming apparatus, it is necessary to detect and ascertain whether the process cartridge is positioned in the image forming apparatus before an image forming operation is started. In the past, the detection of the presence/absence of the cartridge has been mechanically effected by using a contact switch, an actuator and the like. That is to say, when the process cartridge is mounted to the image forming apparatus, the contact switch is turned ON by the actuator; whereas, when the cartridge is dismounted, the contact switch is turned OFF by the actuator. A signal from the contact switch is sent to a controller, thereby judging whether the cartridge is mounted to the image forming apparatus.
However, in the above-mentioned construction for detecting the presence of the process cartridge, since the mechanical parts such as the contact switch and actuator are used, the apparatus was made expensive.
Further, since the parts such as the contact switch and actuator must be provided, it was difficult to make the apparatus small-sized.
Furthermore, it has been desired that the presence/absence of developer in the process cartridge can be detected with a low cost and without making the image forming apparatus large-sized.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a process cartridge and an image forming apparatus, wherein the presence/absence of developer in the process cartridge can be detected with a relatively low cost.
Another object of the present invention is to provide a process cartridge and an image forming apparatus, which can be made small-sized while permitting the detection of the presence/absence of developer in the process cartridge.
A further object of the present invention is to provide a process cartridge and an image forming apparatus, which permits the detection of the presence/absence of the mounting of the process cartridge to the image forming apparatus and can be made small-sized.
The other object of the present invention is to provide a process cartridge and an image forming apparatus, wherein the presence/absence of developer and the presence/absence of the process cartridge can be detected by detecting the electrostatic capacity.


REFERENCES:
patent: 3985436 (1976-10-01), Tanaka et al.
patent: 4133453 (1979-01-01), Ohbora
patent: 4397265 (1983-08-01), Terashima
patent: 4500195 (1985-02-01), Hosono
patent: 4540268 (1985-09-01), Toyono et al.
patent: 4627701 (1986-12-01), Onoda et al.
patent: 4706032 (1987-11-01), Allen et al.
patent: 5003917 (1991-04-01), Toyoshi et al.
patent: 5126800 (1992-06-01), Shishido et al.
patent: 5134441 (1992-07-01), Nagata et al.
patent: 5151734 (1992-09-01), Tsuda et al.
patent: 5198860 (1993-03-01), Yamanaka et al.
patent: 5208634 (1993-05-01), Ikemoto et al.
patent: 5223893 (1993-06-01), Ikemoto et al.
patent: 5229821 (1993-07-01), Fujii
patent: 5276479 (1994-01-01), Inomata
patent: 5283616 (1994-02-01), Numagami et al.
patent: 5331372 (1994-07-01), Tsuda et al.
patent: 5331373 (1994-07-01), Nomura et al.
patent: 5345294 (1994-09-01), Nomura et al.
patent: 5404198 (1995-04-01), Noda et al.
patent: 5450166 (1995-09-01), Yashiro
patent: 5455665 (1995-10-01), Baba et al.
patent: 5475470 (1995-12-01), Sasago et al.
patent: 5500714 (1996-03-01), Yashiro et al.
patent: 5528341 (1996-06-01), Shishido et al.
patent: 5543898 (1996-08-01), Shishido et al.
patent: 5561504 (1996-10-01), Watanabe et al.
patent: 5583613 (1996-12-01), Kobayashi et al.
patent: 5585889 (1996-12-01), Shishido et al.
patent: 5585895 (1996-12-01), Yashiko et al.
patent: 5619309 (1997-04-01), Yashiro et al.
patent: 5623328 (1997-04-01), Isuda et al.
patent: 5638161 (1997-06-01), Numagami et al.
patent: 5652647 (1997-07-01), Yashiro et al.
patent: 5659847 (1997-08-01), Tsuda et al.
patent: 5669042 (1997-09-01), Kobayashi et al.
patent: 5828928 (1998-10-01), Sasago et al.
patent: 5828929 (1998-10-01), Watanabe et al.
patent: 6064842 (2000-05-01), Taeuchi et al.
patent: 55-153970 (1980-12-01), None
patent: 61-77062 (1986-04-01), None
patent: 63-149669 (1988-06-01), None
patent: 4-181266 (1990-06-01), None
patent: 2-304470 (1990-12-01), None
patent: 3-77978 (1991-04-01), None
patent: 3-84562 (1991-04-01), None
patent: 3-121476 (1991-05-01), None
patent: 3-237476 (1991-10-01), None
patent: 3-248176 (1991-11-01), None
patent: 4-13166 (1992-01-01), None
patent: 4-29165 (1992-01-01), None
patent: 4-69669 (1992-03-01), None
patent: 4-162068 (1992-06-01), None
patent: 4-242771 (1992-08-01), None
Murata, “Surface Polymer and Electrostatics,” Japan Surface Science Association, Surface Film Module Design Series 5, Preface, pp. 12-17 with full translation.
Patent Abstract of Japan, vol. 15, No. 254, Jun. 24, 1991.
Patent Abstract of Japan, vol. 5, No. 32, Feb. 27, 1981.
Patent Abstract of Japan, vol. 16, No. 42, Jan. 31, 1992.
Patent Abstract of Japan, vol. 17, No. 14, Jan. 11, 1993.
Patent Abstract of Japan, vol. 15, No. 88, Apr. 3, 1991.
English Abstract of Japanese Patent No. 4-162049.
English Abstract of Japanese Patent No. 3-077978.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Process cartridge and image forming apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process cartridge and image forming apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process cartridge and image forming apparatus will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2934834

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.