Electrophotography – Diagnostics – Consumable
Reexamination Certificate
1999-12-07
2001-07-03
Chen, Sophia S. (Department: 2852)
Electrophotography
Diagnostics
Consumable
C399S223000
Reexamination Certificate
active
06256459
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This document claims priority and contains subject matter related to Japanese Patent Application No. 10-347326 filed in the Japanese Patent Office on Dec. 7, 1998, the entire contents of which are hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a developing apparatus for use in an image forming apparatus, such as a photocopier, a facsimile, a printer, etc., and more particularly to a developing apparatus and method of determining an end-of-toner condition in a toner storage unit.
2. Discussion of the Background
As a background image forming apparatus and a background developing apparatus which determine an end-of-toner condition in a toner storage unit, Japanese Laid-open Patent Publication No. 9-120209 describes an end-of-toner detection device that includes (1) a light path forming unit that protrudes from a wall of a toner storage unit to form a light path along which a light beam passes through an inside of the toner storage unit, and (2) a light sensor of a light-transmission type that includes a light-emitting unit that emits light to a first light-reflecting surface of the light path forming unit and a light-receiving unit that receives the light reflected from a second light-reflecting surface of the light path forming unit. In the above-described end-of-toner detection device, when toner remains in the toner storage unit, the light emitted from the light-emitting unit is blocked by the toner in the light path and does not reach the light-receiving unit. As the amount of toner decreases in the toner storage unit, the intensity of light received by the light-receiving unit increases. In the light sensor, a reference value of the intensity of light received by the light-receiving unit is fixed to detect the end-of-toner condition in the toner storage unit. The light sensor compares the intensity of light received by the light-receiving unit with the reference value, and sends binary output signals (Level High/Level Low) to indicate the end-of-toner condition in the toner storage unit.
However, when the reference value for detecting the end-of-toner condition is fixed in the light sensor, an end-of-toner detection error may be caused by factors such as unevenness of sensitivity of the light sensor, color of toner, etc. For example, when the light sensor has higher sensitivity, the light-receiving unit of the light sensor may receive more light and may determine the end-of-toner condition even though toner remains in the toner storage unit. Further, when the light sensor is stained by scattered toner, the intensity of light received by the light-receiving unit may change, so that an end-of-toner determination error may be caused. Furthermore, because each color toner has a different characteristic of light transmission factor, the intensity of light received by the light-receiving unit may change according to the color of toner, so that an end-of-toner determination error may be caused by the end-of-toner detection employing a fixed reference value.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above-discussed and other problems, and an object of the present invention is to address and resolve the above-discussed and other problems.
Accordingly, one object of the present invention is to provide a novel developing apparatus and method, in which an end-of-toner condition in a toner storage unit is precisely determined.
Another object of the present invention is to provide a novel image forming apparatus and method, in which an end-of-toner condition in a toner storage unit is precisely determined.
The present invention achieves the above and other objects by providing a novel design for an end of toner detector to be utilized in a toner cartridge for a developing apparatus of an image forming apparatus.
A specific embodiment of a developing apparatus of the present invention which achieves the above-noted and other objects includes a developing device which develops latent images formed on an image bearing member so as to form toner images. A toner storage unit stores toner to supply to the developing device. A light path forming unit protrudes from a wall of the toner storage unit into an interior of the toner storage unit and forms the light path through which light passes in the toner storage unit. A light sensor includes a light emitting unit which emits light and a light receiving unit which receives light emitted from the light emitting unit. Further, the light sensor outputs signals which smoothly change according to an amount of toner in the light path formed in the light forming unit.
Other objects, features, and advantages of the present invention will become apparent from the following detailed description when read in conjunction with the accompanying drawings.
REFERENCES:
patent: 5557368 (1996-09-01), Endo et al.
patent: 5671470 (1997-09-01), Maruta et al.
patent: 5826146 (1998-10-01), Maruta et al.
patent: 5899597 (1999-05-01), Shinohara et al.
patent: 5970278 (1999-10-01), Munakata
patent: 8-137175 (1996-05-01), None
patent: 08160698 (1996-06-01), None
patent: 09120209 (1997-05-01), None
patent: 11-327287 (1999-11-01), None
Hasegawa Shin
Ishikawa Tomoji
Kurenuma Takeroh
Yoshioka Makoto
Chen Sophia S.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Ricoh & Company, Ltd.
LandOfFree
Developing apparatus and image forming apparatus using the... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Developing apparatus and image forming apparatus using the..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Developing apparatus and image forming apparatus using the... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2446975