Shape profile measurement device, and shrink-packaging machine

A shape profile measurement device comprising:

• a light projector having a plurality of light-emitting portions arranged in a predetermined array direction, each of the light-emitting portions emitting substantially parallel measurement light;
• a light receiver having a plurality of light-receiving portions arranged in the predetermined array direction facing the plurality of light-emitting portions, each of the light-receiving portions receiving the measurement light emitted from a corresponding light-emitting portion among the plurality of light-emitting portions, and outputting a signal indicating a light intensity of the received measurement light;
• a movement mechanism for causing an object for measurement to move in relation to the light projector and the light receiver so that the object for measurement passes between the plurality of light-emitting portions and the plurality of light-receiving portions;
• and
• a calculation unit for acquiring the signal of the light receiver when the object for measurement is at a plurality of different movement-direction positions between the plurality of light-emitting portions and the plurality of light-receiving portions, and for obtaining a shape profile of the object for measurement on the basis of the signal acquired and information relating to the plurality of movement-direction positions,
• wherein the calculation unit determines that the object for measurement is present on a propagation path on which the measurement light propagates when the light intensity of the measurement light received by the light-receiving portions drops to or below a predetermined threshold in relation to an initial intensity before measurement,
• wherein, based on the shape profile, the calculation unit executes a calculation to obtain a minimum length of a film required for wrapping the object for measurement in said film,
• wherein the calculation unit further executes:
• a calculation to obtain a starting vertex on the shape profile, which is where, when a predetermined straight line approaches the shape profile, that straight line initially makes contact;
• and
• a calculation to obtain an adjacent vertex in a first rotation direction in relation to an arbitrary vertex on the shape profile, wherein, when a straight line passing through said arbitrary vertex is rotated in the first rotation direction about said arbitrary vertex within a plane of the shape profile, that straight line initially makes contact with the shape profile outside of said arbitrary vertex, and
• wherein the calculation to obtain the minimum length of the film comprises:
• obtaining a first adjacent vertex by executing the calculation to obtain an adjacent vertex in the first rotation direction in relation to the starting vertex, and
• obtaining a first line segment joining the starting vertex and the first adjacent vertex as a portion of the minimum length.