Label producing apparatus and label producing method

A label producing apparatus comprising:

• a housing including a discharging exit;
• a feeding device provided inside said housing that feeds a label tape comprising a light-absorbing positioning mark toward said discharging exit;
• a printing device that prints desired print on the label tape to be fed by said feeding device or a print-receiving tape to be bonded to said label tape;
• an optical sensor provided inside said housing, and comprising a light projecting device capable of projecting light toward a feeding path of said label tape to be fed by said feeding device and a light receiving device capable of outputting a detected voltage value corresponding to a received amount of light;
• a light-on control portion that controls said optical sensor so that said light projecting device is turned on in accordance with an input of a label production instruction signal;
• an initial value storage device that stores a predetermined initial threshold value in relation to said detected voltage detected by said light receiving device;
• a threshold value correction portion that calculates a corrected threshold value using said initial threshold value stored in said initial value storage portion in accordance with a correction instruction signal issued at a predetermined time at which said light projecting device is off and an external light can enter the inside of said housing from said discharging exit;
• a mark detecting portion that detects said positioning mark by an arrival of said detected voltage value of said light receiving device at said corrected threshold value after calculation of said corrected threshold value by said threshold value correction portion and with said light projecting device in an on state;
• a feeding control portion that controls said feeding device so that feeding is started in accordance with an input of the label production instruction signal, and to control a feeding operation of said feeding device based on a detection result of said mark detecting portion;
• and
• a print control portion that controls a print operation of said printing device based on the detection result of said mark detecting portion.