Method for selecting writing sheet for stylus, touchscreen system, writing sheet for stylus, touchscreen, and display device

It is intended to provide a method for selecting a writing sheet for a touch panel pen that can accurately select a writing sheet with which the generation of unpleasant sounds during writing is suppressed. According to the method for selecting a writing sheet for a touch panel pen, a sheet satisfying condition 1-1 and condition 1-2 described below is selected as a writing sheet for a touch panel pen. Sound generated when writing is performed under predetermined conditions using a touch panel pen on the surface of a writing sheet for a touch panel pen is recorded. The sound pressure (dB/Hz) is calculated for each 1 Hz from the recorded sound by means of fast Fourier transform. The values of the dB/Hz at frequencies from 1 Hz to 20,000 Hz are normalized to have a maximum value of 100 and a minimum value of 0, and the normalized values of dB/Hz are adopted as rated sound pressures P. The frequencies from 1 Hz to 20,000 Hz are divided into ten segments of 2,000 Hz each, and integrated values of the rated sound pressures P of each segment are calculated. When the integrated value of the rated sound pressures P for frequencies of 1 Hz or more and less than 2,000 Hz as a first segment is represented by P1, and the integrated value of the rated sound pressures P for frequencies of 18,000 Hz or more and 20,000 Hz or less as a tenth segment is represented by P10, P1/P10 is 1.25 or more. When a standard deviation σ of the integrated values of the rated sound pressures P of the ten segments is calculated, σ is 13,500 or less.