A lancing device for use with a removable lancet having a sharp tip. The system also includes a variable-speed fan, and a microprocessor in communication with the fan and configured to control the speed of the fan. Wireless devices then exchange the content, and a network topology is recorded in response. Accordingly, by utilizing the detected information data to set the target value for focus servo, it is possible to carry out more precise focus servo, with managing a variation in the focus servo target value caused by a change in environment such as temperature or a variation in the thickness of the recording medium.