Cordless blind device and method for adjusting cordless blind device

摘要

PROBLEM TO BE SOLVED: To provide a cordless blind device capable of precisely adjusting and adjusting the balance of the device, and an adjusting method for precisely adjusting the balance of the cordless blind device. A cordless blind device includes a winding roll that is connected to a shaft and rotates, a screen member that is wound or unwound by the winding roll, and a torsion spring that rotates together with the winding roll to compress or relax. The increase ratio A1 of the torque applied by the screen member to the take-up roll with respect to the angle of rotation of the take-up roll and the increase ratio A2 of the torque applied by the torsion spring to the take-up roll with respect to the angle of rotation of the take-up roll are determined by Diameter d, Young's modulus E of torsion spring, diameter D of torsion spring, number of turns N of torsion spring, density ρ of screen member, thickness t of screen member, width S of screen member, radius R of take-up roll, gravity For acceleration g, [Correlation] And match each other. [Selection diagram] Figure 1