Abstract: A backrest of chair in which the lower part of a back frame can be concealed neatly by a stretching material. In the backrest device of a chair where a bag like stretching material (12) knitted or woven in the shape of mesh and opening downward is stretched across a back frame (11) formed by coupling the upper ends of right and left side frames (14a) directing the vertical direction by an upper frame (14b) directing the right and left direction, and coupling the lower ends of both the side frames (14a) by a lower frame (14c) which can be fixed to a backrest supporting rod (8) erected from the upper rear of the seat body of the chair, upper portion of the stretching material (12) is made air permeable, and at least a part at the lower portion of the stretching material (12) covering the lower frame (14c) is made non-translucent.

Abstract: A backrest device for a chair, in which a backboard is easily flexible without a reduction in its strength, thus making the chair comfortable to sit on. The lower ends of both right and left sides of the back frame are supported at both sides at the back of a leg body, and the flexible back board is formed on the inside of rear frames. A large number of openings are formed in the backboard so as to be close to each other in the top-bottom and left-right directions. Between openings adjacent to each other in the left-right direction, there is formed a connection section continuing in the top-bottom direction, and the dimension in the front-back direction of the connection section is made larger than the dimension in the left-right direction of the connection section.

Abstract: A backrest of chair in which the lower part of a back frame can be concealed neatly by a stretching material. In the backrest device of a chair where a bag like stretching material (12) knitted or woven in the shape of mesh and opening downward is stretched across a back frame (11) formed by coupling the upper ends of right and left side frames (14a) directing the vertical direction by an upper frame (14b) directing the right and left direction, and coupling the lower ends of both the side frames (14a) by a lower frame (14c) which can be fixed to a backrest supporting rod (8) erected from the upper rear of the seat body of the chair, upper portion of the stretching material (12) is made air permeable, and at least a part at the lower portion of the stretching material (12) covering the lower frame (14c) is made non-translucent.

Abstract: A backrest device for a chair, in which a backboard is easily flexible without a reduction in its strength, thus making the chair comfortable to sit on. The lower ends of both right and left sides of the back frame are supported at both sides at the back of a leg body, and the flexible back board is formed on the inside of rear frames. A large number of openings are formed in the backboard so as to be close to each other in the top-bottom and left-right directions. Between openings adjacent to each other in the left-right direction, there is formed a connection section continuing in the top-bottom direction, and the dimension in the front-back direction of the connection section is made larger than the dimension in the left-right direction of the connection section.