Electrophotography – Diagnostics – Consumable
Reexamination Certificate
1999-09-15
2001-04-10
Grainger, Quana M. (Department: 2852)
Electrophotography
Diagnostics
Consumable
C399S043000
Reexamination Certificate
active
06215966
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of electrophotographic devices, and more particularly to an apparatus and method to recognize when a developing machine is replaced in an electrophotographic apparatus.
2. Description of the Related Art
Generally, in an electrophotographic apparatus such as a copying machine or a laser printer, a photosensitive drum is charged to a high voltage by a high voltage charging roller. Then, an electrostatic latent image is formed on the photosensitive drum by a ray of light from an exposing apparatus such as a laser diode.
At this time, the electrostatic latent image is passed through a developing machine so as to be converted into a visible image formed by toner discharged from the developing machine. The visible image on the photosensitive drum is then transferred to a paper fed by a pickup roller. After the visible image transferred to the paper is thermally fused by heat and pressure of a fixing device, the paper is discharged.
In the laser printer described as above, the developing machine which contains the toner should be replaced after being used for printing a predetermined number of papers. There are two ways for sensing the replacement of the developing machine. One is to provide a separate sensor in the laser printer, to indicate when the developing machine needs to be replaced. However, such a sensor is expensive.
The other way is to continuously count the number of the printed papers after the replacement of the developing machine and to compare the counting number with a printing number corresponding to the life of the developing machine provided by a manufacturer, thereby determining the replacement time of the developing machine. However, in order to identify the replacement time of the developing machine as described above, a counter must be reset. To reset the counter, generally a separate sensor which is expensive should be provided.
In addition to the cost of the sensor itself, the mounting of the separate sensor makes the mechanical construction of the laser printer complicated, and the manufacturing cost is increased.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved electrophotographic apparatus.
It is a further object of the invention to provide an electrophotographic apparatus with an improved apparatus and method for recognizing when a developing machine has been replaced.
It is a yet further object of the invention to provide an electrophotographic apparatus which is simpler in design.
It is a still further object of the invention to provide an electrophotographic apparatus which does not require a sensor to indicate replacement of the developing machine.
It is another object of the present invention to provide an electrophotographic apparatus which is less complex and less expensive to manufacture.
The objects of the present invention are met in the present invention which provides an apparatus and method to identify a replacement of a developing machine which identifies the replacement of the developing machine by confirming whether a fuse provided on the developing machine is disconnected when an upper cover of the printer is opened and then closed or power source is off, and which initializes a counter when the developing machine is replaced with new one, whereby a user can identify the replacement status of the developing machine so as to decide the replacement time of the developing machine without using a separate sensor.
To achieve the above objects and other advantages, there is provided an apparatus to identify a replacement of a developing machine which includes: a fuse which is disposed at a desired position of the developing machine; a switching part which is disposed at a desired position of a printer body corresponding to the fuse and applies a level of current to the fuse according to a control signal so as to disconnect, that is, blow, the fuse; a control unit which outputs a control signal to the switching part so as to check whether the fuse is disconnected when a warming-up operation of a printer is started, and which outputs a control signal to a power controller so as to disconnect the fuse if the fuse is not disconnected and then initializes a printing counter, wherein the developing machine is determined to have been replaced, if the fuse is not disconnected.
Preferably, the control unit comprises a central processing unit which entirely controls the apparatus and a RAM which initializes the printing counter if the fuse is disconnected by the control signal.
Further, it is preferred that the switching part comprises a transistor of which a base is connected with an output terminal and a collector is connected with a power terminal and an emitter is connected with the fuse so that the switching part is turned on if a first level of current is supplied from the CPU and a second level of current is supplied from the power terminal so as to disconnect the fuse; and a diode of which a cathode is connected with an input terminal of the CPU and an anode is connected with the transistor and a node of the fuse so that the diode is turned on by the second level of current through the transistor if the fuse is disconnected.
Further, according to the present invention, there is provided a method to identify a replacement of a developing machine, includes steps of: checking whether a fuse is disconnected when a warning-up operation of a printer is started; disconnecting the fuse and initializing a printing counter if the fuse is not disconnected; increasing a number of the printing counter by one whenever one paper is printed and storing the number in a storing means.
Preferably, the method further comprises a step of outputting the number of the printing counter stored in the storing means if the user inputs an order of checking the number of the printing counter.
It is preferred that the step of checking whether a fuse is disconnected comprises steps of: initializing the number of the printing counter and applying a power to the fuse so as to disconnect the fuse; checking whether the fuse is disconnected; increasing the number of the printing counter if the fuse is not disconnected, and comparing a predetermined standard number with the counting number; outputting an error message if the counting number is same with the standard number, and disconnecting the fuse if the counting number is less than the standard number.
REFERENCES:
patent: 5021828 (1991-06-01), Yamaguchi et al.
patent: 5315351 (1994-05-01), Matsushiro et al.
patent: 5740491 (1998-04-01), Imai
patent: 5758224 (1998-05-01), Binder et al.
patent: 5835817 (1998-11-01), Bullock et al.
Park Sung-Guen
Yang Chul-Joo
Bushnell , Esq. Robert E.
Grainger Quana M.
Samsung Electronics Co,. Ltd.
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