Charged particle sensor

Claim 3

An apparatus according to claim 1, wherein said member includes a substantially transparent prism.

Claim 4

An apparatus according to claim 2, wherein said prism is a right triangular prism having equal opposed interior angles.

Claim 5

An apparatus according to claim 3, wherein said transparent plate is secured to said prism on the surface thereof opposed from the right angle therein.

Claim 7

An apparatus according to claim 5, wherein said light source is secured to a surface of said prism other than the surface of said prism having said transparent plate secured thereto.

Claim 8

An apparatus according to claim 6, wherein said detecting means includes a light sensor positioned to receive light rays internally reflected through said prism and said transparent plate.

Claim 9

An apparatus according to claim 6, wherein said light sensor is secured to a surface of said prism.

Claim 10

An apparatus according to claim 8, wherein said transparent plate includes a substantially transparent, electrically conductive layer.

Claim 11

An apparatus according to claim 9, wherein said conductive layer is of a substantially uniform area.

Claim 12

An apparatus according to claim 9, wherein said conductive layer is arranged in a pattern of conductive and non-conductive regions.

Claim 13

An apparatus according to claim 2, further including means for diverting a portion of the charged particles in the passageway between said pair of plates toward said transparent plate.

Claim 14

An apparatus according to claim 12, wherein said diverting means includes a magnetic member positioned before said prism in the direction of flow of the charged particles.

Claim 15

An apparatus according to claim 2, wherein said detecting means generates a signal indicative of the quantity of charged particles attracted to the surface of said transparent plate.

Claim 16

An electrophotographic printing machine of the type having an electrostatic latent image recorded on a photoconductive surface developed with charged particles from a developer mixture, wherein the improvement includes: a pair of spaced-apart conductive plates defining a passageway through which a portion of the developer mixture flows with at least one of said pair of plates being substantially transparent; a member secured to one surface of said transparent plate; means for electrically biasing said transparent plate to attract a portion of the charged particles in the developer mixture to the other surface thereof; means for transmitting a beam of energy through said member and said transparent plate with the internal angle of incidence of the beam of energy being greater than the critical angle of incidence of said members; and means for detecting the intensity of the beam of energy internally reflected through said transparent plate and said member.

Claim 17

An electrophotographic printing machine of the type having an electrostatic latent image recorded on a photoconductive surface developed with charged particles from a developer mixture, wherein the improvement includes: a pair of spaced-apart conductive plates defining a passageway through which a portion of the developer mixture flows with at least one of said pair of plates being substantially transparent; a member secured to one surface of said transparent plate; means for electrically biasing said transparent plate to attract a portion of the charged particles in the developer mixture to the other surface thereof; means for transmitting a beam of energy through said member and said transparent plate with the internal angle of incidence of the beam of energy being greater than the critical angle of incidence of said members; and means for detecting the intensity of the beam of energy internally reflected through said transparent plate and said member.

Claim 18

A printing machine according to claim 15, wherein said member includes a substantially transparent prism.

Claim 19

A printing machine according to claim 16, wherein said prism is a right triangular prism having equal opposed interior angles.

Claim 20

A printing machine according to claim 17, wherein said transparent plate is secured to said prism on the surface thereof opposed from the right angle therein.

Claim 21

A printing machine according to claims 16 or 18, wherein said transmitting means includes a light source transmitting light rays through said prism and said transparent plate onto the charged particles adhering thereto.

Claim 22

A printing machine according to claim 19, wherein said light source is secured to a surface of said prism other than the surface of said prism having said transparent plate secured thereto.

Claim 23

A printing machine according to claim 20, wherein said detecting means includes a light sensor positioned to receive light rays internally reflected through said prism and said transparent plate.

Claim 24

A printing machine according to claim 21, wherein said light sensor is secured to a surface of said prism.

Claim 25

A printing machine according to claim 22, wherein said transparent plate includes a substantially transparent, electrically conductive layer.

Claim 26

A printing machine according to claim 23, wherein said conductive layer is of a substantially uniform area.

Claim 27

A printing machine according to claim 24, wherein said conductive layer is arranged in a pattern of conductive and non-conductive regions.

Claim 28

A printing machine according to claim 16, further including means for diverting a portion of the developer mixture flowing in the passageway between said pair of plates toward said transparent plate.

Claim 29

A printing machine according to claim 26, wherein said diverting means includes a magnetic member positioned before said prism in the direction of flow of the developer mixture.

Claim 30

A printing machine according to claim 16, wherein said detecting means generates a signal indicative of the quantity of charged particles attracted to the surface of said transparent plate.