An electronic device test apparatus called a “handler” conveys a large number of IC devices housed on a tray into the handler, brings the IC devices into electrical contact with a test head, and uses the main unit of the electronic device test apparatus (hereinafter also referred to as a “tester”) to run tests. Further, when the tests end, it ejects the tested IC devices from the test head and reloads them on trays in accordance with the test results so as to sort them into categories such as good devices and defective devices.
Among such handlers, it has been known in the past to prevent miscontact between IC devices and sockets by using image processing technology to position the IC devices relative to the sockets with a high precision before bringing them into contact with the sockets (for example, see Patent Document 1).
Usually, the sockets on a test head are fabricated in accordance with the types of the IC devices, so each time the type of the IC devices are changed, the sockets are changed to other sockets tailored to those devices. For this reason, handlers using image processing technology has to be calibrated in positions of CCD cameras with respect to sockets after the change (for example, see Patent Document 2).    Patent Document 1: International Publication No. 03/075023    Patent Document 2: Japanese Patent Publication (A) No. 2001-51018