Item management system, item management method, item detection instrument, and item detection device

An item management method comprising:

• arranging an item detection instrument that includes a placement member, a communication device, and a radio wave shield member, the placement member being provided for placing an item and movable between a first position and a second position, a communication device being attached to the placement member, the radio wave shield member being configured to shield radio waves emitted from the communication device when the radio wave shield member is close to the communication device;
• causing the placement member to be at a first position with no item placed on the placement member, resulting in the communication device being separated from the radio wave shield member, and thereby allowing a wireless device to communicate with the communication device;
• causing the placement member to move to the second position with an item placed on the placement member, and resulting in the communication device being close to the radio wave shield member;
• acquiring a result of whether communication by the wireless device with the communication device is possible;
• and
• determining whether the item is placed on the placement member, based on the result of whether the communication is possible.

An item detection instrument for detecting an item, comprising:

• a placement member for placing an item, the placement member being at a first position when no item is placed on the placement member, the placement member moving from the first position to a second position when an item is placed on the placement member;
• a communication device attached to the placement member;
• and
• a radio wave shield member configured to shield radio waves emitted from the communication device when the radio wave shield member is close to the communication device, wherein
• when the placement member is at the first position, the communication device is separated from the radio wave shield member, and when the placement member is at the second position, the communication device is close to the radio wave shield member.

An item detection device comprising a plurality of item detection instruments arranged in a matrix and each provided for detecting an item,

• the plurality of item detection instruments each including:
• a placement member for placing an item, the placement member being at a first position when no item is placed on the placement member, the placement member moving from the first position to a second position when an item is placed on the placement member;
• a communication device attached to the placement member;
• and
• a radio wave shield member configured to shield radio waves emitted from the communication device when the radio wave shield member is close to the communication device, wherein
• when the placement member is at the first position, the communication device is separated from the radio wave shield member, and when the placement member is at the second position, the communication device is close to the radio wave shield member.