Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
152 words
An apparatus for machining the periphery of an electrically nonconductive workpiece, comprising: a grinding wheel with an electrically conductive grinding surface, means for holding either said workpiece or, an electrically conductive test piece having a predetermined bevel, moving means for changing the relative distance between said holding means and said wheel, touch sensor means for generating a touch signal when the bevel of said test piece held by said holding means electrically contacts the grinding surface of said wheel, and control means coupled to said touch sensor means and to said moving means, for detecting, when said touch signal is generated, machining end position data (N1) corresponding to the relative distance between said holding means and said wheel, and for actuating, when said workpiece is held by said holding means, said moving means according to said machining end position data (N1), so that machining of the periphery of said workpiece is effected.
Claim 2
Independent Claim
152 words
An apparatus for machining the periphery of an electrically nonconductive workpiece, comprising: a grinding wheel with an electrically conductive grinding surface, means for holding either said workpiece or, an electrically conductive test piece having a predetermined bevel, moving means for changing the relative distance between said holding means and said wheel, touch sensor means for generating a touch signal when the bevel of said test piece held by said holding means electrically contacts the grinding surface of said wheel, and control means coupled to said touch sensor means and to said moving means, for detecting, when said touch signal is generated, machining end position data (N1) corresponding to the relative distance between said holding means and said wheel, and for actuating, when said workpiece is held by said holding means, said moving means according to said machining end position data (N1), so that machining of the periphery of said workpiece is effected.
Claim 3
Dependent Claim
87 words
The apparatus of claim 1, wherein said control means includes: a memory for storing predetermined machining amount data (N2) and predetermined feeding amount data (N3) which are defined in accordance with the size of said test piece; and computer means for generating a command signal which determines the relative distance between said holding means and said wheel in accordance with said machining end position data (N1), said machining amount data (N2) and said feeding amount data (N3), said command signal being used for actuating said moving means.
Claim 4
Dependent Claim
34 words
The apparatus of claim 2, wherein said moving means includes actuator means for changing the relative distance between said holding means and said wheel in accordance with the command signal from said computer means.
Claim 5
Independent Claim
27 words
The apparatus of claims 3, wherein said holding means is moved by said actuator means so that the periphery of said workpiece is ground by said wheel.
Claim 6
Dependent Claim
12 words
The apparatus of claim 1, wherein said workpiece is a silicon wafer.
Claim 7
Dependent Claim
11 words
The apparatus of claim 5, wherein said workpiece includes a thyristor.
Claim 8
Dependent Claim
164 words
The apparatus of claim 2, wherein: the relative distance between said holding means and said wheel is changed by forward/backward movement of said holding means; the relative distance between said holding means and said wheel when said workpiece is mounted on said holding means is determined in accordance with total stroke data (N2+N3) which is a sum of said machining amount data (N2) and said feed amount data (N3), with reference to said machining end position data (N1); the relative distance between said holding means and said wheel when the periphery of said workpiece is moved in a forward direction to a position immediately in front of said grinding surface of said wheel is determined in accordance with said feeding amount data (N3) with reference to said total stroke data (N2+N3); and the relative distance between said holding means and said wheel when said workpiece is ground by said grinding surface of said wheel is determined in accordance with said machining amount data (N2).
Claim 9
Dependent Claim
71 words
The apparatus of claim 4, wherein: said moving means includes a movable table on which said holding means is placed, said movable table being movable in a first direction and in a second direction which is different from said first direction; and said actuator means comprises a first actuator for moving said movable table in said first direction and a second actuator for moving said movable table in said second direction.
Claim 10
Dependent Claim
55 words
The apparatus of claim 8, wherein: said first actuator moves said movable table in said first direction for a distance corresponding to said machining amount data (N2); said second actuator moves said table in said second direction for a distance corresponding to said feeding amount data (N3); and said first and second directions are orthogonal.
Claim 11
Dependent Claim
33 words
The apparatus of claim 8, wherein said first actuator moves said movable table in said first direction for a distance corresponding to said machining amount data (N2) and said feeding amount data (N3).
Claim 12
Dependent Claim
28 words
The apparatus of claim 8, wherein: said holding means has first motor means for rotating said workpeice; and said wheel has second motor means for rotating said wheel.
Claim 13
Dependent Claim
18 words
The apparatus of claim 8, wherein said wheel has means for reciprocating said wheel in said second direction.
Claim 14
Dependent Claim
31 words
The apparatus of claim 8, wherein said second actuator has means for reciprocating said movable table in said second direction when the periphery of said workpiece is ground by said wheel.