Calibrating jig, profile measuring device, and method of offset calculation

A profile measuring device, comprising:

• a first probe configured to acquire information related to a profile of an object-to-be-measured by imaging an image based on reflected light from said object-to-be-measured;
• a second probe configured to acquire information related to the profile of said object-to-be-measured, said second probe being provided at a different position to said first probe;
• a calibrating jig to be measured by said first probe and said second probe;
• a measuring section for measuring said calibrating jig by said first probe and said second probe, respectively, to obtain a first measurement result and a second measurement result respectively;
• and
• an offset calculating section for comparing said first measurement result and said second measurement result to calculate an offset between said first measurement result and said second measurement result,
• said calibrating jig including:
• a reference sphere;
• and
• a reflecting plate configured to support the reference sphere from a lower side thereof:
• wherein the reflecting plate and the reference sphere are configured such that light irradiated from above the reference sphere is returned in a same direction as a direction of incidence by a top of the reference sphere and by the reflecting plate.

A method of offset calculation in which a profile measuring device is used to calculate an offset in said profile measuring device, said profile measuring device comprising:

• a first probe configured to acquire information related to a profile of an object-to-be-measured by imaging an image based on reflected light from said object-to-be-measured;
• a second probe configured to acquire information related to the profile of said object-to-be-measured, said second probe being provided at a different position to said first probe;
• and a calibrating jig to be measured by said first probe and said second probe, said calibrating jig including:
• a reference sphere;
• and
• a reflecting plate configured to support the reference sphere from a lower side thereof:
• wherein the reflecting plate and the reference sphere are configured such that light irradiated from above the reference sphere is returned in a same direction as a direction of incidence by a top of the reference sphere and by the reflecting plate, said method comprising the steps of:
• measuring said calibrating jig by said first probe and said second probe, respectively, to obtain a first measurement result and a second measurement result respectively;
• and
• comparing said first measurement result and said second measurement result to calculate an offset between said first measurement result and said second measurement result.