Operation apparatus

An operation apparatus comprising:

• an imaging unit which has a preset imaging range and which images a target within the imaging range;
• an index determining unit which determines whether a particular index image has intruded into the imaging range;
• and
• a notification unit which generates vibration or a voice signal when the index determining unit determines that a tip of the index image overlaps a predetermined image part within the imaging range,
• wherein the predetermined image detecting unit is configured to determine a change direction of a changed part of image information and a no-change direction, and
• the notification unit notifies in accordance with the relation between a change direction of the index image and a change direction of image information.

A target checking method comprising:

• imaging a target within an imaging range;
• determining whether an image of a particular index has intruded into the imaging range;
• and
• notifying that the index image is determined to overlap a predetermined image part within the imaging range, wherein the notification is performed in accordance with a relation between a change direction of the index image and a change direction of image information.

A non-transitory storage medium storing a program, the program causing a computer to perform:

• imaging by using an imaging unit;
• determining whether a particular index image has intruded into an imaging range of the imaging unit;
• determining the index image;
• determining that a tip of the index image overlaps a predetermined image part within the imaging range;
• and
• notifying that the index image is determined to overlap a predetermined image part within the imaging range, wherein the notification is performed in accordance with a relation between a change direction of the index image and a change direction of image information.