Tool length measuring method and tool length measuring device

1. A tool length measuring method measuring a length of a tool based on a movement amount of the tool from a predetermined position when the tool is moved from the predetermined position in a predetermined direction and interrupts a laser beam, the method comprising stopping the movement of the tool in a direction in which the tool approaches a main body of a laser device when detecting a first signal indicating that the tool is interrupting the laser beam, wherein, when a second signal which is output when the tool shifts from a state where the tool does not interrupt the laser beam to a state where the tool interrupts the laser beam is detected, a tool length measuring program is continued, and wherein the first signal is output later than the second signal.

2. A tool length measuring device measuring a length of a tool based on a movement amount of the tool from a predetermined position when the tool is moved from the predetermined position in a predetermined direction and interrupts a laser beam, the device comprising: a main body of a laser device including a laser beam generating part generating the laser beam, a laser beam receiving part receiving the laser beam generated by the laser beam generating part, and a first signal output part outputting a first signal indicating that the tool is interrupting the laser beam; and a program controller stopping the movement of the tool in a direction in which the tool approaches the main body of the laser device when detecting the first signal, wherein the main body of the laser device further includes a second signal output part outputting a second signal when the tool shifts from a state where the tool does not interrupt the laser beam to a state where the tool interrupts the laser beam, and wherein the first signal is output later than the second signal.