Method and apparatus for detecting an exchange period for parts within an electrophotographic printing apparatus

#This application makes reference to, incorporates herein and claims all benefits accruing under 35 U.S.C..sctn.119 from our application earlier filed in the Korean Industrial Property Office on 25 May 1993 of our application entitled Method and An Exchange Period Alarm Equipment of Exchangeable Parts Within An Electrophotographic Recording Apparatus, which application was duly assigned Ser. No. 9091/1993.

#The present invention relates to a method and apparatus for detecting an exchange period for parts within an electrophotographic printing apparatus, and more particularly to a control method and apparatus for sensing when a replaceable part within an electrophotographic printing apparatus has received a requisite amount of use and automatically informing a user of such status.

#In electrophotographic printing devices, in order to ensure continuous high quality printing, it is highly recommended that certain parts within the device be replaced after a prescribed amount of use. That is, to ensure high quality printing in a LBP (Laser Beam Printer), LED (Light Emitting Diode) printer, duplicator, facsimile, etc., parts such as the photosensitive drum should be replaced after the printing output of the device reaches a prescribed quantity. There are several replaceable parts within an electrophotographic printing device, including the photosensitive drum, developing unit, etc. Timely replacement of these parts improves copy quality and visibility, and also lengthens the operating life of the device.

#A more complete appreciation of this invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:

#FIG. 1 is a block diagram of a controller and a replaceable part within a conventional electrophotographic printing apparatus.

#FIG. 2 is a flow chart of operation of the controller used in a conventional electrophotographic printing apparatus.

#FIG. 1 is a block diagram of a controller and a replaceable part within a conventional electrophotographic printing apparatus. Referring to FIG. 1, a developing cartridge 20 (i.e. the replaceable part) includes a photosensitive drum 12, a toner supplier 14 for supplying toner to photosensitive drum 12, and a toner sensor 16 for detecting the amount of toner remaining in toner supplier 14. FIG. 1 also shows a controller 22 for determining the number of copies that have been produced by the printer while developing cartridge 20 has been in use. Controller 22 outputs a replacement message when developing cartridge 20 has been used to produce a predetermined number of copies. Controller 22 includes a counter portion (CNT) 21 and a memory portion 23.

#In FIG. 1, controller 22 counts the number of copies produced using developing cartridge 20, analyzes a toner volume detection signal output from toner sensor 16, perceives how much toner remains in toner supplier 14, and outputs a corresponding message.

#FIG. 2 is a flow chart of operation of controller 22 used in a conventional electrophotographic printing apparatus. Referring to FIGS. 1 and 2, the following describes operations for detecting when a particular part should be replaced within a conventional electrophotographic printing apparatus. When the printing apparatus performs a print command, m controller 22 activates developing cartridge 20 to initiate the printing process in step 29. In step 30, a counter portion CNT 21 of controller 22 is incremented by one for each copy produced during the printing process. Controller 22 then checks the value of counter CNT 21, in step 31. This value, representing the number of copies which have been produced with developing cartridge 20, is also stored in a memory portion 23 of controller 22 in step 31. Next, controller 22 compares the stored counter value with a predetermined use value also stored in memory portion 23. The predetermined use value represents the number of copies developing cartridge 20 can produce before replacement is suggested. In step 32, controller 22 determines whether or not the counter value is equal to the predetermined use value. If the counter value is below the predetermined use value for developing cartridge 20, controller 22 returns to step 30. In the above description, the predetermined use value for a particular part is specified by manufacturers of the part.