Optical instrument, imaging apparatus, and method of manufacturing optical instrument

An optical instrument comprising:

• a first part configured to hold an optical element;
• a second part configured to hold the first part;
• and
• a biasing member that includes a first engagement portion and a second engagement portion, wherein:
• one of the first part and the second part includes a third engagement portion that is engageable with the first engagement portion and a fourth engagement portion that is engageable with the second engagement portion,
• the other one of the first part and the second part includes a fifth engagement portion that is engageable with the second engagement portion, and
• a first clearance between the first part and the second part is narrower than the second engagement portion in both a first state in which the second engagement portion is engaged with the fourth engagement portion and a second state in which the second engagement portion is engaged with the fifth engagement portion.

A method of manufacturing an optical instrument including a first part configured to hold an optical element, a second part, and a biasing member that includes a first engagement portion and a second engagement portion, the method comprising:

• causing the first engagement portion engage a third engagement portion provided in one of the first part and the second part;
• causing the second engagement portion engage a fourth engagement portion;
• causing the second part to hold the first part;
• disengaging the second engagement portion from the fourth engagement portion;
• and
• causing the second engagement portion to engage a fifth engagement portion provided in the other one of the first part and the second part.