Vibration visualizer, vibration measurement system, and vibration measurement method

A vibration visualizer comprising

• an optical member including
• a fixed section to be fixed to a measurement object;
• and
• a movable section movably supported by the fixed section such that a first positional relationship between the fixed section and the movable section is changed by application of an acceleration to the fixed section in a predetermined direction, wherein
• the optical member changes a reflection intensity of light or electromagnetic wave reflected in a retroreflection direction according to a change of the first positional relationship,
• the first positional relationship in a stationary state where the acceleration is not applied to the fixed section and the first positional relationship is maintained constant, is different from the first positional relationship most suitable for retroreflection,
• the optical member includes a corner cube having three reflection faces perpendicular to each other, and a deformation member contacting with the corner cube,
• at least a part of the corner cube is included in the fixed section,
• the deformation member is included in the movable section and supported by the fixed section such that at least one of the three reflection faces is deformed by the deformation member by the application of the acceleration to the fixed section in the predetermined direction, and
• in the stationary state, the at least one of the three reflection faces of the corner cube is deformed by the deformation member.

A vibration visualizer comprising

• an optical member including
• a fixed section to be fixed to a measurement object;
• and
• a movable section movably supported by the fixed section such that a first positional relationship between the fixed section and the movable section is changed by application of an acceleration to the fixed section in a predetermined direction, wherein
• the optical member changes a reflection intensity of light or electromagnetic wave reflected in a retroreflection direction according to a change of the first positional relationship,
• the first positional relationship in a stationary state where the acceleration is not applied to the fixed section and the first positional relationship is maintained constant, is different from the first positional relationship most suitable for retroreflection,
• the optical member includes a spherical lens and a reflective member having a concave reflective surface, the reflective member being located behind the spherical lens,
• one of the spherical lens and the reflective member is included in the fixed section,
• the other of the spherical lens and the reflective member is included in the movable section and supported by the fixed section such that a second positional relationship between the one and the other is changed by the application of the acceleration to the fixed section in the predetermined direction, and
• in the stationary state, a curvature center of the spherical lens and a curvature center of the concave reflective surface is displaced from each other.

A vibration measurement system comprising:

• a first vibration visualizer, and a second vibration visualizer, each of which comprises:
• an optical member including
• a fixed section to be fixed to a measurement object;
• and
• a movable section movably supported by the fixed section such that a first positional relationship between the fixed section and the movable section is changed by application of an acceleration to the fixed section in a predetermined direction,
• wherein the optical member changes a reflection intensity of light or electromagnetic wave reflected in a retroreflection direction according to a change of the first positional relationship, and
• the first positional relationship in a stationary state where the acceleration is not applied to the fixed section and the first positional relationship is maintained constant, is different from the first positional relationship most suitable for retroreflection;
• a lighting device that emits light or electromagnetic wave to the first vibration visualizer and the second vibration visualizer which are fixed to the measurement object;
• an imaging device that captures an image depicting the measurement object, the first vibration visualizer and the second vibration visualizer;
• and
• a vibration measurement device that measures the change of the first positional relationship between the fixed section and the movable section in each of the first vibration visualizer and the second vibration visualizer, based on a change of a luminance of reflected light or a change of an amount of reflected electromagnetic wave from each of the first vibration visualizer and the second vibration visualizer in the image captured by the imaging device.