Filter for removing smoke and toner dust used in electrophotographic/electrostatic recording apparatus

Claim 2

An electrophotographic/electrostatic recording apparatus, wherein a toner image is formed on a recording sheet, the recording apparatus generating smoke and toner dust particles in air, the toner dust particles having a predetermined average toner particle size and including toner particles having a charge, the recording apparatus comprising: a fixing unit for fusing the toner image to the recording sheet to fix the toner image on the recording sheet; a flash lamp connected to said fixing unit; and an air filter having an air inlet side, positioned to remove the smoke and toner dust particles from the air and including a first filter unit disposed at the air inlet side and having a first outlet side, and at least a second filter unit disposed at the first outlet side of said first filter unit and having a second outlet side; said first filter unit comprising electrostatically charged fibrous material attracting the charged toner particles and having a polarity opposite to the charged toner particles, said first filter unit having a first predetermined porosity greater than the predetermined average toner particle size; and said second filer unit comprising fibrous material without an electrostatic charge and having a second predetermined porosity less than the predetermined average toner particle size.

Claim 3

An electrophotographic/electrostatic recording apparatus as recited in claim 1, wherein said toner particles are both large and fine and have the predetermined average toner particle size of about 10 microns and include toner particles charged with a positive polarity, wherein said first filter unit includes negatively charged fibrous material for attracting the charged toner particles, and the first predetermined porosity greater than about 10 microns for removing a substantial part of the large toner dust particles from the air and for allowing the fine toner dust particles and smoke to pass therethrough, respectively, and wherein fibrous material of said second filter unit has a second porosity less than about 10 microns for removing the fine toner particles and smoke.

Claim 4

An electrophotographic/electrostatic recording apparatus as recited in claim 2, wherein said charged fibrous material is made of a fibrous dielectric material and a solution coating of vinylidene flouride and methyl ethyl ketone coated onto said fibrous material.

Claim 5

An electrophotographic/electrostatic recording apparatus as recited in claim 1, wherein said toner particles are both large and fine and have the predetermined average toner particle size of about 10 microns and include toner particles charged with a negative polarity, wherein said first filter unit includes positively charged fibrous material for attracting the charged toner particles, and the first predetermined porosity greater than about 10 microns for removing a substantial part of the large toner dust particles from the air and for allowing the fine toner dust particles and smoke to pass therethrough respectively, and wherein fibrous material of said second filter unit has a second porosity less than about 10 micron, for removing the fine toner particles and smoke.

Claim 6

An electrophotographic/electrostatic recording apparatus as recited in claim 4, wherein said charged fibrous material is made of a fibrous dielectric material and a solution coating of styrene acrylic and methyl ethyl ketone coated onto said fibrous material.

Claim 7

An electrophotographic/electrostatic recording apparatus as recited in claims 1, 4 or 2, wherein said air filter further comprises a deodorization filter unit for deodorizing the air adjacent to said first and second filter units, said deodorization filter unit comprising activated carbon particles and being disposed at an exhaust side of said air filter.

Claim 8

An electrophotographic/electrostatic recording apparatus as recited in any of claims 1, 4, 2 or 5, wherein said first and second filter units comprise a planar structure.

Claim 9

An electrophotographic/electrostatic recording apparatus as recited in any of claim 1, 4, 2 or 5, wherein said first and second filter units comprise a cylindrical structure.

Claim 10

An electrophotographic/electrostatic recording apparatus as recited in any of claims 1, 4, 2, 5 or 3, wherein said first filter unit further comprises a separator of folded corrugated material.

Claim 11

An electrophotographic/electrostatic recording apparatus as recited in any of claims 1, 4, 2, 5 or 3, wherein said air filter further comprises at least a third filter unit disposed between the second filter unit and an outlet side, said third filter unit including fibrous material without an electrostatic charge, said uncharged fibrous material having a third predetermined porosity less than the porosity of the second filter unit.

Claim 12

An electrophotographic/electrostatic recording apparatus as recited in claim 10, wherein said first, second and third filter units comprise a planar structure.

Claim 13

An electrophotographic/electrostatic recording apparatus as recited in claim 10, wherein said first, second and third filter units comprise a cylindrical structure.

Claim 14

An electrophotographic/electrostatic recording apparatus, including an air filter for removing smoke and toner dust particles from air, wherein said apparatus forms a toner image on a recording sheet by fusing the toner image to the recording sheet, the toner dust particles being both large and fine, having a predetermined average toner particle size of about 10 microns, and having a negative charge, said air filter having an air inlet side, the apparatus comprising: a flash lamp for fusing the toner image to the recording sheet; a first filter unit disposed at the air inlet side and having a first outlet side, and at least a second filter unit disposed at the first outlet side of said first filter unit and having a second outlet side; said first filter unit including positively electrostatically charged fibrous material for attracting the negatively charged toner particles, said firs filter unit having a first predetermined porosity greater than about 10 microns for removing the large toner dust particles from the air and for allowing the fine toner dust particles and smoke to pass therethrough; and said second filter unit including fibrous material without an electrostatic charge and having a second predetermined porosity less than about 10 microns for removing the fine toner dust particles and smoke.

Claim 15

An electrophotographic/electrostatic recording apparatus, including an air filter for removing smoke and toner dust particles from air, wherein said apparatus forms a toner image on a recording sheet by fusing the toner image to the recording sheet, the toner dust particles being both large and fine, having a predetermined average toner particle size of about 10 microns, and having a negative charge, said air filter having an air inlet side, the apparatus comprising: a flash lamp for fusing the toner image to the recording sheet; a first filter unit disposed at the air inlet side and having a first outlet side, and at least a second filter unit disposed at the first outlet side of said first filter unit and having a second outlet side; said first filter unit including positively electrostatically charged fibrous material for attracting the negatively charged toner particles, said firs filter unit having a first predetermined porosity greater than about 10 microns for removing the large toner dust particles from the air and for allowing the fine toner dust particles and smoke to pass therethrough; and said second filter unit including fibrous material without an electrostatic charge and having a second predetermined porosity less than about 10 microns for removing the fine toner dust particles and smoke.

Claim 16

An air filter for removing smoke and toner dust particles from air, the toner dust particles being both large and fine, having a predetermined average toner particle size of about 10 microns, and being charged with a positive polarity, said air filter having an air inlet side and an air outlet side and comprising: (a) a first filter unit disposed at the air inlet side of the air filter; and (b) at least a second filter unit disposed between said first filter unit and said air outlet side; wherein said first filter unit includes a negatively electrostatically charged fibrous material for attracting the positively charged toner particles, and a fist predetermined porosity greater than about 10 microns for removing a substantial part of the large toner dust particles from the air and for allowing the fine toner dust particles and smoke to pass therethrough; and wherein said second filter unit includes fibrous material without an electrostatic charge, said uncharged fibrous material having a second predetermined porosity less than about 10 microns for removing the fine toner dust particles and smoke.

Claim 17

An air filter for removing smoke and toner dust particles from air, the toner dust particles being both large and fine, having a predetermined average toner particle size of about 10 microns, and being charged with a positive polarity, said air filter having an air inlet side and an air outlet side and comprising: (a) a first filter unit disposed at the air inlet side of the air filter; and (b) at least a second filter unit disposed between said first filter unit and said air outlet side; wherein said first filter unit includes a negatively electrostatically charged fibrous material for attracting the positively charged toner particles, and a fist predetermined porosity greater than about 10 microns for removing a substantial part of the large toner dust particles from the air and for allowing the fine toner dust particles and smoke to pass therethrough; and wherein said second filter unit includes fibrous material without an electrostatic charge, said uncharged fibrous material having a second predetermined porosity less than about 10 microns for removing the fine toner dust particles and smoke.