Method and apparatus of charging for transfer in electrophotograph device

Claim 2

An electrophotograph device comprising: (a) means for forming an electrostatic latent image on an electrographic recording medium uniformly charged with charges of a given polarity; (b) developing means for applying toner charged with a predetermined polarity of charges to said medium in order to develop said electrostatic latent image; (c) means for charging a movable transferring object which is operatively associated with said medium with a predetermined polarity of charges in order to transfer toner from said medium to said transferring object; (d) means for moving said movable transferring object at variable speeds; (e) means for detecting the speed of movement of said transferring object; (f) means for generating a pulse train having a frequency which is proportional to the speed of movement of said transferring object which is detected by said detecting means; and (g) means for receiving said pulse train and means for applying transferring voltage pulses to said transferring object, in response to the frequency of the pulse train received, at a frequency which is proportional to said speed of movement.

Claim 3

Apparatus according to claim 1 wherein said detecting means comprises a rotary whose output signal is a pulse train of a frequency determined in accordance with the detected speed of the transferring object.

Claim 4

Apparatus according to claim 2 wherein said means for applying transferring voltage pulses comprises a switching circuit for selectively applying a high voltage to said means for charging, and a control circuit that controls the operation of the switching circuit in response to the output signal of the rotary encoder.

Claim 5

Apparatus according to claim 1 wherein the electrographic recording medium is a rotating photosensitive drum.

Claim 6

Apparatus according to claim 4 wherein said detecting means comprises a rotary encoder whose output signal is a pulse train of a frequency determined in accordance with the detected speed of the transferring object.

Claim 7

Apparatus according to claim 5 wherein said means for applying transferring voltage pulses comprises a switching circuit for selectively applying a high voltage to said means for charging, and a control circuit that controls the operation of the switching circuit in response to the output signal of the rotary encoder.

Claim 8

Apparatus according to claim 4 wherein the transferring object is a paper sheet.

Claim 9

Apparatus according to claim 7 wherein said detecting means comprises a rotary encoder whose output signal is a pulse train of a frequency determined in accordance with the detected speed of the transferring object.

Claim 10

Apparatus according to claim 8 wherein said means for applying transferring voltage pulses comprises a switching circuit for selectively applying a high voltage to said means for charging, and a control circuit that controls the operation of the switching circuit in response to the output signal of the rotary encoder.

Claim 11

An electrophotograph device comprising: (a) means for forming an electrostatic latent image on an electrographic recording medium uniformly charged with charges of a given polarity; (b) developing means for applying toner charged with charges of the same polarity as said electrostatic recording medium to said medium in order to develop said electrostatic latent image; (c) means for charging a movable transferring object which is operatively associated with said medium with charges of a polarity which is different from the polarity of the charged electrostatic recording medium in order to transfer toner from said medium to said transferring object; (d) means for moving said movable transferring object at variable speeds; (e) means for detecting the speed of movement of said transferring object; (f) means for generating a pulse train having a frequency which is proportional to the speed of movement of said transferring object which is detected by said detecting means; and (g) means for receiving said pulse train and means for applying transferring voltage pulses to said transferring object, in response to the frequency of the pulse train received, at a frequency which is proportional to said speed of movement, wherein said detecting means comprises a rotary encoder which outputs a signal, in the form of said pulse train having a frequency determined in accordance with the detected speed of said transferring object, said pulse train being outputted to a frequency control circuit and a wave shaping circuit, said wave shaping circuit comprising means for outputting a generally rectangular wave to a triangular wave forming circuit, said triangular wave forming circuit, in turn, comprising means for outputting a triangular wave form to a comparator which compares said triangular wave to a reference voltage inputted into said comparator, said apparatus further comprising a switching circuit for thereafter selectively applying high voltage pulses at a controlled frequency to said means for charging.

Claim 12

An electrophotograph device comprising: (a) means for forming an electrostatic latent image on an electrographic recording medium uniformly charged with charges of a given polarity; (b) developing means for applying toner charged with charges of the same polarity as said electrostatic recording medium to said medium in order to develop said electrostatic latent image; (c) means for charging a movable transferring object which is operatively associated with said medium with charges of a polarity which is different from the polarity of the charged electrostatic recording medium in order to transfer toner from said medium to said transferring object; (d) means for moving said movable transferring object at variable speeds; (e) means for detecting the speed of movement of said transferring object; (f) means for generating a pulse train having a frequency which is proportional to the speed of movement of said transferring object which is detected by said detecting means; and (g) means for receiving said pulse train and means for applying transferring voltage pulses to said transferring object, in response to the frequency of the pulse train received, at a frequency which is proportional to said speed of movement, wherein said detecting means comprises a rotary encoder which outputs a signal, in the form of said pulse train having a frequency determined in accordance with the detected speed of said transferring object, said pulse train being outputted to a frequency control circuit and a wave shaping circuit, said wave shaping circuit comprising means for outputting a generally rectangular wave to a triangular wave forming circuit, said triangular wave forming circuit, in turn, comprising means for outputting a triangular wave form to a comparator which compares said triangular wave to a reference voltage inputted into said comparator, said apparatus further comprising a switching circuit for thereafter selectively applying high voltage pulses at a controlled frequency to said means for charging.

Claim 13

An electrograph device comprising: (a) means for forming an electrostatic latent image on a photosensitive drum and for charging said photosensitive drum uniformly with charges of a predetermined polarity; (b) a developing unit for applying toner charged with charges of said predetermined polarity to said drum in order to develop said electrostatic latent image; (c) a transferring charger for charging a movable paper sheet operatively associated with said drum in order to charge said sheet with charges of a polarity which is different from the polarity of said drum in order to transfer toner from said drum to said paper sheet; (d) means for moving said paper sheet at variable speeds; (e) a rotary encoder for detecting the speed of movement of said paper sheet, said rotary encoder comprising means for outputting a signal in the form of a pulse train of a frequency which is established in response to the detected speed of movement of said paper sheet, said rotary encoder comprising means for outputting said pulse train to a frequency control circuit which in turn comprises means for outputting a signal to a wave shaping circuit, said wave shaping circuit comprising means for outputting a generally rectangular wave to a triangular wave forming circuit, said triangular wave forming circuit in turn comprising means for outputting a triangular wave to a comparator which compares the triangular wave to a reference voltage inputted into said comparator; and (f) a switching circuit for selectively applying high voltage pulses at a controlled frequency to said charging means, said controlled frequency being proportional to the speed of movement of the paper sheet.

Claim 14

An electrograph device comprising: (a) means for forming an electrostatic latent image on a photosensitive drum and for charging said photosensitive drum uniformly with charges of a predetermined polarity; (b) a developing unit for applying toner charged with charges of said predetermined polarity to said drum in order to develop said electrostatic latent image; (c) a transferring charger for charging a movable paper sheet operatively associated with said drum in order to charge said sheet with charges of a polarity which is different from the polarity of said drum in order to transfer toner from said drum to said paper sheet; (d) means for moving said paper sheet at variable speeds; (e) a rotary encoder for detecting the speed of movement of said paper sheet, said rotary encoder comprising means for outputting a signal in the form of a pulse train of a frequency which is established in response to the detected speed of movement of said paper sheet, said rotary encoder comprising means for outputting said pulse train to a frequency control circuit which in turn comprises means for outputting a signal to a wave shaping circuit, said wave shaping circuit comprising means for outputting a generally rectangular wave to a triangular wave forming circuit, said triangular wave forming circuit in turn comprising means for outputting a triangular wave to a comparator which compares the triangular wave to a reference voltage inputted into said comparator; and (f) a switching circuit for selectively applying high voltage pulses at a controlled frequency to said charging means, said controlled frequency being proportional to the speed of movement of the paper sheet.

Claim 15

An electrographic device comprising: (a) means for forming an electrostatic image on an electrographic recording medium uniformly charged with charges of a given polarity; (b) developing means for applying toner charged with a predetermined polarity of charges to said medium in order to develop said electrostatic latent image; (c) means for charging a movable transferring object which is operably associated with said medium with a predetermined polarity of charges in order to transfer toner from said medium to said transferring object; (d) means for moving said movable transferring object at variable speeds; (e) means for detecting the speed of movement of said transferring object; (f) means for generating a pulse train having a frequency which is proportional to the speed of movement of said transferring object which is detected by said detecting means; and (g) means for receiving said pulse train and means for applying transferring voltage pulses to said transferring object, in response to the frequency of the pulse train received, at a frequency which is proportional to said speed of movement, wherein said detecting means comprises a rotary encoder which outputs a signal, in the form of said pulse train having a frequency determined in accordance with the detected speed of said transferring object, said pulse train being outputted to a frequency control circuit and a wave shaping circuit, said wave shaping circuit comprising means for outputting a generally rectangular wave to a triangular wave forming circuit, said triangular wave forming circuit, in turn, comprising means for outputting a triangular wave form to a comparator which compares said triangular wave to a reference voltage inputted into said comparator, said apparatus further comprising a switching circuit for thereafter selectively applying high voltage pulses at a controlled frequency to said means for charging.

Claim 16

An electrographic device comprising: (a) means for forming an electrostatic image on an electrographic recording medium uniformly charged with charges of a given polarity; (b) developing means for applying toner charged with a predetermined polarity of charges to said medium in order to develop said electrostatic latent image; (c) means for charging a movable transferring object which is operably associated with said medium with a predetermined polarity of charges in order to transfer toner from said medium to said transferring object; (d) means for moving said movable transferring object at variable speeds; (e) means for detecting the speed of movement of said transferring object; (f) means for generating a pulse train having a frequency which is proportional to the speed of movement of said transferring object which is detected by said detecting means; and (g) means for receiving said pulse train and means for applying transferring voltage pulses to said transferring object, in response to the frequency of the pulse train received, at a frequency which is proportional to said speed of movement, wherein said detecting means comprises a rotary encoder which outputs a signal, in the form of said pulse train having a frequency determined in accordance with the detected speed of said transferring object, said pulse train being outputted to a frequency control circuit and a wave shaping circuit, said wave shaping circuit comprising means for outputting a generally rectangular wave to a triangular wave forming circuit, said triangular wave forming circuit, in turn, comprising means for outputting a triangular wave form to a comparator which compares said triangular wave to a reference voltage inputted into said comparator, said apparatus further comprising a switching circuit for thereafter selectively applying high voltage pulses at a controlled frequency to said means for charging.