Non-contact wet or dry film thickness measuring device

Claim 1

A device for measuring the thickness of a film applied on a substrate without contacting the film, comprising; (a) first optical sensor means for measuring a first distance value between the top surface of the film and the device; (b) second inductive eddy-current proximity sensor means generally oval in shape and has a slot extending about a center axis thereof coaxial with said first means for measuring a second distance value between the top surface of the substrate and the device; and said optical sensor means is positioned centrally above said proximity sensor means and projects a light beam through said slot; and wherein the optical axis of symmetry is coaxial with the proximity sensor means axis and the beam intersects the proximity sensor means axis at the top surface of the film; and (c) said first and second means disposed on the same side of the substrate; and (d) means electrically connected with said first and second means for calculating the film thickness by comparing said first and second distance values.

Claim 2

A device for measuring the thickness of a film applied on a substrate without contacting the film, comprising; (a) first optical sensor means for measuring a first distance value between the top surface of the film and the device; (b) second inductive eddy-current proximity sensor means generally oval in shape and has a slot extending about a center axis thereof coaxial with said first means for measuring a second distance value between the top surface of the substrate and the device; and said optical sensor means is positioned centrally above said proximity sensor means and projects a light beam through said slot; and wherein the optical axis of symmetry is coaxial with the proximity sensor means axis and the beam intersects the proximity sensor means axis at the top surface of the film; and (c) said first and second means disposed on the same side of the substrate; and (d) means electrically connected with said first and second means for calculating the film thickness by comparing said first and second distance values.

Claim 4

A device for applying film to a substrate comprising: (a) means for applying the film to the substrate; (b) means for receiving a signal from a film thickness measuring device defined below and determining increase or decrease in the amount of film to be applied to a next substrate and transmitting a signal to said film applying means for controlling the amount of film to be applied; wherein the film thickness measuring device measures film thickness of a film applied on a substrate without contacting the film and comprises: (1) optical sensor means for measuring a first distance value between the top surface of the film and the device; (2) inductive eddy-current proximity sensor means coaxial with said optical sensor means for measuring a second distance value between the top surface of the substrate and the device, said proximity sensor having a central opening through which the optical sensor measures the first distance value whereby the proximity sensor does not interfere with the optical sensor; (3) said optical sensor means and said proximity sensor means disposed on the same side of the substrate; and (4) means electrically connected with said optical sensor means and said proximity sensor means for calculating the film thickness by comparing said first and second distance values and means for feeding a signal to the above adjusting means.

Claim 5

A device for applying film to a substrate comprising: (a) means for applying the film to the substrate; (b) means for receiving a signal from a film thickness measuring device defined below and determining increase or decrease in the amount of film to be applied to a next substrate and transmitting a signal to said film applying means for controlling the amount of film to be applied; wherein the film thickness measuring device measures film thickness of a film applied on a substrate without contacting the film and comprises: (1) optical sensor means for measuring a first distance value between the top surface of the film and the device; (2) inductive eddy-current proximity sensor means coaxial with said optical sensor means for measuring a second distance value between the top surface of the substrate and the device, said proximity sensor having a central opening through which the optical sensor measures the first distance value whereby the proximity sensor does not interfere with the optical sensor; (3) said optical sensor means and said proximity sensor means disposed on the same side of the substrate; and (4) means electrically connected with said optical sensor means and said proximity sensor means for calculating the film thickness by comparing said first and second distance values and means for feeding a signal to the above adjusting means.

Claim 6

A device for measuring the thickness of a film applied on a substrate without contacting the film, comprising: (a) optical sensor means for measuring a first distance value between the top surface of the film and the device; (b) inductive eddy-current proximity sensor means coaxial with said optical sensor means for measuring a second distance value between the top surface of the substrate and the device, said proximity sensor having a central opening through which the optical sensor measures the first distance value whereby the proximity sensor does not interfere with the optical sensor; (c) said optical sensor means and said proximity sensor means disposed on the same side of the substrate; and (d) means electrically connected with said optical sensor means and said proximity sensor means for calculating the film thickness by comparing said first and second distance values.

Claim 7

A device for measuring the thickness of a film applied on a substrate without contacting the film, comprising: (a) optical sensor means for measuring a first distance value between the top surface of the film and the device; (b) inductive eddy-current proximity sensor means coaxial with said optical sensor means for measuring a second distance value between the top surface of the substrate and the device, said proximity sensor having a central opening through which the optical sensor measures the first distance value whereby the proximity sensor does not interfere with the optical sensor; (c) said optical sensor means and said proximity sensor means disposed on the same side of the substrate; and (d) means electrically connected with said optical sensor means and said proximity sensor means for calculating the film thickness by comparing said first and second distance values.

Claim 9

A device for measuring the thickness of a film applied on a substrate without contacting the film, comprising: (a) optical sensor means for measuring a first distance value between the top surface of the film and the device; (b) inductive eddy-current proximity sensor means coaxial with said optical sensor means for measuring a second distance value between the top surface of the substrate and the device, said proximity sensor having a central opening through which the optical sensor measures the first distance value whereby the proximity sensor does not interfere with the optical sensor; (c) auxiliary sensor means spaced from said proximity sensor means for measuring a third distance value between the top surface of the substrate and the device; (d) said optical sensor means, said proximity sensor means, and said auxiliary sensor means all disposed on the same side of the substrate; (e) means electrically connected with said optical sensor means, said proximity sensor means, and said auxiliary sensor means for calculating the film thickness by comparing said first, second, and third distance values.

Claim 10

A device for measuring the thickness of a film applied on a substrate without contacting the film, comprising: (a) optical sensor means for measuring a first distance value between the top surface of the film and the device; (b) inductive eddy-current proximity sensor means coaxial with said optical sensor means for measuring a second distance value between the top surface of the substrate and the device, said proximity sensor having a central opening through which the optical sensor measures the first distance value whereby the proximity sensor does not interfere with the optical sensor; (c) auxiliary sensor means spaced from said proximity sensor means for measuring a third distance value between the top surface of the substrate and the device; (d) said optical sensor means, said proximity sensor means, and said auxiliary sensor means all disposed on the same side of the substrate; (e) means electrically connected with said optical sensor means, said proximity sensor means, and said auxiliary sensor means for calculating the film thickness by comparing said first, second, and third distance values.