| 摘要 |
<p>PROBLEM TO BE SOLVED: To protect a user against interruption in the circulation of the blood without pressing the vein of the wrist by providing a core material made of rubbery substance where plural projection parts are formed at the position where a wrist is not pressed on the side of a top surface coming into contact with the hand of the user. SOLUTION: The core material is made of the rubbery substance and provided with nearly crescent-sectioned projection parts 22 on the top surface 21. The projection parts 22 are arranged along the length of the top surface 21 and formed in a thin and long arcuate shape in plane view. The projection parts 22 are about 1 to 5 mm thicker on the width-directional deep side as a keyboard side at the time of use than on the front side. Consequently, an angle closer to the angle of the hand of the user who operates the keyboard is obtained and the user can operate the key board in a comfortable posture and the projection parts 22 are provided preferably at the position where the hands can be made stable according to the arrangement of the hands operating the keyboard, so that they will be standards for the arrangement of the hands when the user operates the keyboard.</p> |
