Apparatus and method for forming images by jetting recording liquid onto an image carrier by applying both vibrational energy and electrostatic energy

An image forming apparatus for forming liquid images onto an image carrier, comprising:

• a photosensitive body;
• an electrostatic latent image forming mechanism which forms electrostatic latent images onto said photosensitive body;
• a multi-nozzle head having a plurality of nozzles for jetting an ink drop to said electrostatic latent images in order to visualize images,
• said multi-nozzle head including an ink charger, an ink supply, and a main body into which a piezoelectric body having protruding portions corresponding to each of said plurality of nozzles and a supporting member having hollowed portions corresponding to each of said plurality of nozzles are united,
• said protruding portions and said hollowed portions having a space therebetween for ink to go through,
• said ink charger charging ink in said space, and
• said ink supply supplying ink to said space;
• and
• a voltage supplying circuit for vibrating each protruding portion of said piezoelectric body,
• wherein a composite energy of said vibration and said electrostatic field forms a drop of said ink and jets said drop from said nozzles of said multi-nozzle head to said image carrier to form liquid images.

An image forming apparatus for forming liquid images onto an image carrier, comprising:

• ink holding means for holding ink;
• a plurality of piezoelectric bodies provided in said ink holding means, each of which corresponds to a pixel of images to be formed;
• one common electrode provided on one side of each of said piezoelectric bodies in a direction orthogonal to a direction heading for said image carrier from said ink holding means;
• a plurality of separate electrodes provided on a side opposite to said common electrode on each of said piezoelectric bodies, said plurality of separate electrodes applying voltage corresponding to image signals of each of said pixels to be formed and to vibrate corresponding piezoelectric bodies;
• and
• electrostatic field forming means for giving electrostatic energy to attract said ink held by said ink holding means toward said image carrier;
• wherein a composite energy of said vibration and said electrostatic field forms a drop of said ink and jets said drop from said ink holding means to said recording medium to form liquid images.

An image forming apparatus for forming an ink image onto an image carrier, comprising:

• a first plate having a plurality of protruding portions which are aligned on a same side of said first plate, said protruding portions being made of a piezoelectric material;
• a second plate, provided separately from said first plate, having a plurality of hollow portions on a same side of said second plate corresponding to said protruding portions, respectively, each of said protruding portions being inserted into a respective one of said hollow portions so that a space is defined between a top surface of each of said protruding portions and a bottom surface of each of said hollow portions to form ink rooms having openings through which ink is jetted;
• an ink supply which is connected with said ink rooms to supply ink into said ink rooms;
• a plurality of electrodes which are provided on said plurality of protruding portions, respectively;
• and
• a driver which is connected with each of said electrodes to apply a voltage for driving each of said protruding portions.

An image forming apparatus for forming an ink image onto an image carrier, comprising:

• a first plate having a plurality of protruding portions which are aligned on a same side of said first plate, said protruding portions being made of a piezoelectric material;
• a second plate, provided separately from said first plate, having a plurality of hollow portions on a same side of said second plate corresponding to said protruding portions, respectively, each of said protruding portions being inserted into a respective one of said hollow portions so that a space is defined between a top surface of each of said protruding portions and a bottom surface of each of said hollow portions to form ink rooms having openings through which ink is jetted;
• an ink supply which is connected with said ink rooms to supply ink into said ink rooms;
• a plurality of electrodes which are provided on said top surfaces of said protruding portions, respectively;
• and
• a driver which is connected with each of said electrodes to apply a voltage for driving each of said protruding portions.

An image forming apparatus for forming an ink image onto an image carrier, comprising:

• a piezoelectric plate having a plurality of protruding portions aligned on a same side of said piezoelectric plate;
• a cover plate, provided separately from said piezoelectric plate, having a plurality of hollow portions on a same side of said cover plate corresponding to said protruding portions, respectively, each of said protruding portions being inserted into a respective one of said hollow portions so that a space is defined between a top surface of each of said protruding portions and a bottom surface of each of said hollow portions to form ink rooms having openings through which ink is jetted;
• an ink supply which is connected with said ink rooms to supply ink into said ink rooms;
• and
• driving means for driving each of said protruding portions individually.

An ink jet head for jetting ink to an image carrier, comprising:

• a first plate having a plurality of protruding portions which are aligned on a same side of said first plate, said protruding portions being made of a piezoelectric material;
• a second plate, provided separately from said first plate, having a plurality of hollow portions on a same side of said second plate corresponding to said protruding portions, respectively, each of said protruding portions being inserted into a respective one of said hollow portions so that a space is defined between a top surface of each of said protruding portions and a bottom surface of each of said hollow portions to form ink rooms having openings through which ink is jetted;
• an ink supply which is connected with said ink rooms to supply ink into said ink rooms;
• and
• a plurality of electrodes which are provided on said top surfaces of said protruding portions, respectively.

An ink jet head for jetting ink onto an image carrier, comprising:

• a piezoelectric plate having a plurality of protruding portions aligned on a same side of said piezoelectric plate;
• a cover plate, provided separately from said piezoelectric plate, having a plurality of hollow portions on a same side of said cover plate corresponding to said protruding portions, respectively, each of said protruding portions being inserted into a respective one of said hollow portions so that a space is defined between a top surface of each of said protruding portions and a bottom surface of each of said hollow portions to form ink rooms having openings through which ink is jetted;
• and
• an ink supply which is connected with said ink rooms to supply ink into said ink rooms.

A method for making an ink jet head comprising steps of:

• forming a plurality of parallel grooves on a same side of a piezoelectric plate to define a plurality of protruding portions, each of which is located between the neighboring grooves;
• forming a plurality of grooves on a same side of a cover plate corresponding to said protruding portions of said piezoelectric plate, respectively;
• and
• inserting each of said protruding portions of said piezoelectric plate into a respective one of said grooves of said cover plate to form an ink room between a top surface of each of said protruding portions of said piezoelectric plate and a bottom surface of each of said grooves of said cover plate.