Vibratory assisted direct marking method and apparatus

A method of producing an image on an image receiving member in a direct marking apparatus having an endless photoconductive member with an inner layer, a charge retentive outer layer, and a conductive electrode layer interposed between the inner and outer layers, including the steps of:

• (a) uniformly depositing, on an outer surface of the photoconductive member, electrically charged marking particles, said particles being deposited thereon by an electrically biased developer and attracted thereto;
• (b) charging the photoconductive member and electrically charged marking particles deposited thereon with a corona charging device;
• (c) selectively exposing regions of the photoconductive member to a light source so as cause the collapse of the electric field in the exposed regions;
• (d) applying an electrical bias to the image receiving member, spaced apart from the outer surface of the photoconductive member, to generate an electric field in a gap between the image receiving member and the photoconductive member;
• and
• (e) applying acoustic energy to the photoconductive member so as to further reduce adhesive forces present between the outer surface of the photoconductive member and the marking particles, said acoustic energy being of sufficient magnitude to enable only the marking particles present on the surface of the photoconductive member in the unexposed regions to be transferred to an outer surface of the image receiving member under the force of the electric field.

A printing apparatus, comprising:

• an endless photoconductive member having an inner layer, a charge retentive outer layer, and a conductive electrode layer between the inner and outer layers;
• charged marking particles uniformly deposited on an outer surface of the photoconductive member and held in relative contact therewith;
• means for selectively exposing the photoconductive member to light to produce both exposed and unexposed regions therein and to thereby cause the collapse of the electric field in the exposed regions;
• an image receiving member, spaced apart from the outer surface of the photoconductive member, for receiving the marking particles, said image receiving member having an electrical bias applied thereto to neutralize an electric field present in a gap between the image receiving member and the exposed regions of the photoconductive member;
• and
• means for applying acoustic energy to the photoconductive member so as to further reduce adhesive forces present between the outer surface of the photoconductive member and the marking particles, said acoustic energy applying means applying acoustic energy having sufficient magnitude to enable only the marking particles present on the surface of the photoconductive member in the unexposed regions to be transferred to an outer surface of the image receiving member.

A printing apparatus, comprising:

• an endless photoconductive member having an inner layer, a charge retentive outer layer, and a conductive electrode layer between the inner and outer layers;
• charged marking particles uniformly deposited on an outer surface of the photoconductive member and held in relative contact therewith;
• a corona charging device for charging the photoconductive member and electrically charged marking particles deposited thereon;
• means for selectively exposing the photoconductive member to light to produce both exposed and unexposed regions therein and to thereby cause the collapse of an electric field in the exposed regions;
• an image receiving member, spaced apart from the outer surface of the photoconductive member, for receiving the marking particles, said image receiving member having an electrical bias applied thereto to neutralize an electric field present in a gap between the image receiving member and the exposed regions of the photoconductive member;
• and
• means for applying acoustic energy to the photoconductive member so as to further reduce adhesive forces present between the outer surface of the photoconductive member and the marking particles, said acoustic energy applying means applying acoustic energy having sufficient magnitude to enable only the marking particles present on the surface of the photoconductive member in the unexposed regions to be transferred to an outer surface of the image receiving member.

A multi-color printing apparatus for producing an image on a recording sheet, comprising:

• an intermediate member;
• a plurality of direct marking devices for depositing marking material on an outer surface of said intermediate member to produce an image thereon, each of said direct marking devices including,
• an endless photoconductive member having an inner layer, a charge retentive outer layer, and a conductive electrode layer between the inner and outer layers,
• charged marking particles on an outer surface of the photoconductive member and held in relative contact therewith by an electric field created by the charged particles being deposited on the photoconductive member,
• means for selectively exposing the photoconductive member to light to produce both exposed and unexposed regions therein and to thereby cause the collapse of the electric field in the exposed regions,
• an image receiving member, spaced apart from the outer surface of the photoconductive member, for receiving the marking particles, said image receiving member having an electrical bias applied thereto to neutralize an electric field present in a gap between the image receiving member and the exposed regions of the photoconductive member, and
• means for applying acoustic energy to the photoconductive member so as to further reduce adhesive forces present between the outer surface of the photoconductive member and the marking particles, said acoustic energy applying means applying acoustic energy having sufficient magnitude to enable only the marking particles present on the surface of the photoconductive member in the unexposed regions to be transferred to an outer surface of the image receiving member;
• a heater, in communication with an internal surface of said intermediate member, for heating said intermediate member so as to cause the tackification of the marking particles deposited on the outer surface thereof;
• and
• means, defining a nip with the outer surface of said intermediate member, for transferring the tackified marking particle image to the recording sheet passing through the nip defined by said intermediate member and said transferring means, whereby the tackified marking particle image is cooled upon contact with the recording sheet to become permanently fixed to the surface thereof.

A printing apparatus, comprising:

• an endless photoconductive member having an inner layer, a charge retentive outer layer, and a conductive electrode layer between the inner and outer layers;
• charged marking particles uniformly deposited on an outer surface of the photoconductive member and held in relative contact therewith;
• means for selectively exposing the photoconductive member to light to produce regions having a collapsed electric field;
• an image receiving member, spaced apart from the outer surface of the photoconductive member, for receiving marking particles, said image receiving member having an electrical bias applied thereto to neutralize an electric field present in a gap between the image receiving member and those regions of the photoconductive member having the collapsed electric field;
• and
• means for applying vibratory energy to the marking particles present on the photoconductive member so as to further reduce adhesive forces present between the outer surface of the photoconductive member and the marking particles, said vibratory energy applying means applying energy of sufficient magnitude to enable only the marking particles present on the surface of the photoconductive member in the regions having the collapsed electric field to be transferred to an outer surface of the image receiving member.