Patent ID: 11927934
Assignee: DISCO CORPORATION
Field: Control (Instruments)
Classification: CPC B  G | IPC G

Claim 1:
2. A cutting apparatus comprising:
a chuck table for holding a workpiece thereon;
a cutting unit for cutting the workpiece held on the chuck table with a cutting blade mounted on a spindle; and
a management unit for managing the cutting blade mounted on the spindle,
wherein the management unit includes:
a light emitter for emitting light,
a light receiver facing the light emitter, for receiving the light emitted from the light emitter,
a measuring unit for measuring an amount of light emitted from the light emitter and received by the light receiver while the cutting blade is positioned between the light emitter and the light receiver,
a measured waveform forming section for forming a measured waveform representing a configuration of an outer circumferential region of the cutting blade from the amount of light measured at a plurality of rotational angles of the cutting blade,
an ideal waveform forming section for forming an ideal waveform representing a configuration of the outer circumferential region of the cutting blade, wherein the cutting blade is mounted on the spindle with a predetermined eccentricity, wherein the predetermined eccentricity is a predetermined deviation between a rotational axis of the spindle and a center of the cutting blade,
a difference calculating section for calculating an area of a region where there is a difference between the measured waveform and the ideal waveform that are superposed on each other, and
a determining section for determining that the configuration of the cutting blade is abnormal if the difference exceeds a threshold value,
wherein the ideal waveform forming section calculates an intermediate value between a maximum value and a minimum value of the measured waveform, and forms a waveform whose amplitude is represented by a difference between the intermediate value and the maximum value and between the intermediate value and the minimum value, depending on the predetermined eccentricity of the cutting blade, as the ideal waveform.