A disclosed laser diode driving circuit causes a laser diode to emit light by varying a current value of a current source in accordance with a control signal input externally and supplying a current that is the same as or proportional to the current value to the laser diode. Preferred catalysts comprise ferric and cupric oxides. , and the 60\xb0, 45\xb0, 20\xb0 specular reflection of the image surface on which the metallic image is formed is 100% or greater, and a brightness is 20 or greater. MRI monitors the location of the target. A hook is configured to secure the length in a loop, and a ratchet mechanism controllably decreases a circumference of the loop to secure the back frame to the tree.