Abstract: A method is described. The method includes obtaining a relationship between a thickness of a contamination layer formed on a mask and an amount of compensation energy to remove the contamination layer, obtaining a first thickness of a first contamination layer formed on the mask from a thickness measuring device, and applying first compensation energy calculated from the relationship to a light directed to the mask.

Abstract: Sport bat 10, made of laminated wood 50, such as of bamboo 51. Bat 10 includes handle 45, taper portion 44 and batting portion 30. Batting portion 30 includes one or more internal chambers 31 for decreasing the weight of bat 10. Internal chambers 31 may be reinforced with sleeve insert 32, rubbery coating 34, or porous filler 33. Internal chamber 31 is disposed between taper portion 44 and sweet spot 12.

Abstract: A shock-absorbing device is designed for use in a game apparatus having a tubular rod body. The game apparatus comprises a ball-hitting portion, and a grip portion. The ball-hitting portion is formed of a frame, a ball-hitting face defined by the frame, and a neck extending from the frame. The grip portion is formed of a hollow rod and is fastened with the neck. The neck is provided with at least one groove and one shock-absorbing device which is disposed in the groove. The groove is extended along the longitudinal direction of the neck and toward the grip portion. The shock-absorbing device is formed of an absorbing member and a weight body which is put through the absorbing member and is capable of swiveling upon being exerted on by an external force.

Abstract: A shock-absorbing device is designed for use in a game apparatus having a tubular rod body. The game apparatus comprises a ball-hitting portion, and a grip portion. The ball-hitting portion is formed of a frame, a ball-hitting face defined by the frame, and a neck extending from the frame. The grip portion is formed of a hollow rod and is fastened with the neck. The neck is provided with at least one groove and one shock-absorbing device which is disposed in the groove. The groove is extended along the longitudinal direction of the neck and toward the grip portion. The shock-absorbing device is formed of an absorbing member and a weight body which is put through the absorbing member and is capable of swiveling upon being exerted on by an external force.