Displacement meter, storage medium, manufacturing system, and method for manufacturing articles

A displacement meter comprising:

• an incoherent light source configured to illuminate an object to be measured;
• a double telecentric optical system configured to receive diffused-reflected light generated on a surface of the object that has been illuminated by the incoherent light source;
• an image pickup unit configured to receive diffused-reflected light through the double telecentric optical system to output an image;
• and
• at least one processor or circuit configured to function as:
• a calculation unit configured to calculate the displacement of the object to be measured,
• wherein the calculation unit calculates a displacement amount of the object to be measured by using sub-pixel estimation and using a cross-correlation function between reference image data and measurement image data, in which an image acquired during a predetermined timing from an imaging unit serves as the reference image data and an image acquired after the predetermined timing serves as the measurement image data,
• generates a value obtained by adding a correction value to the displacement amount to serve as a correction displacement amount,
• sets the most recent measurement image data as the reference image data and sets the displacement amount obtained most recently as the correction value in a case where the displacement amount meets a predetermined condition, and
• does not change the reference image data and the correction value in a case where the displacement amount does not meet the predetermined condition.

A non-transitory computer-readable storage medium configured to store a computer program to control a displacement meter, the displacement meter comprising:

• an incoherent light source configured to illuminate an object to be measured;
• a double telecentric optical system configured to receive diffused-reflected light generated on a surface of the object that has been illuminated by the incoherent light source;
• an image pickup unit configured to receive diffused-reflected light through the double telecentric optical system to output an image;
• and
• at least one processor or circuit configured to function as:
• a calculation unit configured to calculate the displacement of the object to be measured,
• wherein the computer program comprises instructions for causing the calculation unit to execute following processes:
• calculating a displacement amount of the object to be measured by using sub-pixel estimation and using a cross-correlation function between reference image data and measurement image data, in which an image acquired during a predetermined timing from an imaging unit serves as the reference image data and an image acquired after the predetermined timing serves as the measurement image data;
• generating a value obtained by subtracting a correction value from the displacement amount to serve as a correction displacement amount;
• setting the most recent measurement image data as the reference image data and setting a predetermined initial value as the correction value in a case where the displacement amount meets a predetermined condition;
• and
• setting the displacement amount obtained most recently as the correction value in a case where the displacement amount does not meet the predetermined condition.

An article manufacturing method using a displacement meter, the displacement meter comprising:

• an incoherent light source configured to illuminate an object to be measured;
• a double telecentric optical system configured to receive diffused-reflected light generated on a surface of the object that has been illuminated by the incoherent light source;
• an image pickup unit configured to receive diffused-reflected light through the double telecentric optical system to output an image;
• and
• a calculation unit configured to calculate the displacement of the object to be measured,
• wherein the article manufacturing method comprises the steps of:
• calculating a displacement amount of an object to be measured by using sub-pixel estimation and by using a cross-correlation function between reference image data and measurement image data, in which an image acquired during a predetermined timing from an imaging unit serves as the reference image data and an image acquired after the predetermined timing serves as the measurement image data,
• generating a value obtained by subtracting a predetermined correction value from the displacement amount to serve as a correction displacement amount,
• setting the most recent measurement image data as the reference image data and setting a predetermined initial value as the correction value in a case where the displacement amount meets a predetermined condition,
• setting the displacement amount obtained most recently as the correction value in a case where the displacement amount does not meet the predetermined condition, and
• calculating the displacement amount or a speed of the object to be measured by the calculation unit and
• manufacturing an article by processing the object to be measured based on the displacement amount or the speed.

A non-transitory computer-readable storage medium configured to store a computer program to control a displacement meter, the displacement meter comprising:

• an incoherent light source configured to illuminate an object to be measured;
• a double telecentric optical system configured to receive diffused-reflected light generated on a surface of the object that has been illuminated by the incoherent light source;
• an image pickup unit configured to receive diffused-reflected light through the double telecentric optical system to output an image;
• and
• at least one processor or circuit configured to function as:
• a calculation unit configured to calculate the displacement of the object to be measured,
• wherein the computer program comprises instructions for causing the calculation unit to execute following processes:
• calculating a displacement amount of the object to be measured by using sub-pixel estimation and using a cross-correlation function between reference image data and measurement image data, in which an image acquired during a predetermined timing from an imaging unit serves as the reference image data and an image acquired after the predetermined timing serves as the measurement image data,
• generating a value obtained by adding a correction value to the displacement amount to serve as a correction displacement amount,
• setting the most recent measurement image data as the reference image data and setting the displacement amount obtained most recently as the correction value in a case where the displacement amount meets a predetermined condition, and
• inhibiting changing the reference image data and the correction value in a case where the displacement amount does not meet the predetermined condition.

An article manufacturing method using a displacement meter, the displacement meter comprising:

• an incoherent light source configured to illuminate an object to be measured;
• a double telecentric optical system configured to receive diffused-reflected light generated on a surface of the object that has been illuminated by the incoherent light source;
• an image pickup unit configured to receive diffused-reflected light through the double telecentric optical system to output an image;
• and
• wherein the article manufacturing method comprises the steps of:
• calculating a displacement of the object to be measured by using sub-pixel estimation and using a cross-correlation function between reference image data and measurement image data, in which an image acquired during a predetermined timing from an imaging unit serves as the reference image data and an image acquired after the predetermined timing serves as the measurement image data,
• generating a value obtained by adding a correction value to the displacement amount to serve as a correction displacement amount,
• setting the most recent measurement image data as the reference image data and sets the displacement amount obtained most recently as the correction value in a case where the displacement amount meets a predetermined condition,
• inhibiting changing the reference image data and the correction value in a case where the displacement amount does not meet the predetermined condition;
• and
• manufacturing an article by processing the object to be measured based on the displacement amount or the speed.