Method for manufacturing strip-shaped glass film

A method of manufacturing a band-shaped glass film, the method comprising:

• a forming step of forming a band-shaped glass film while drawing the band-shaped glass film downward in a vertical direction;
• a conveyance direction changing step of changing a conveyance direction of the band-shaped glass film from a vertically downward direction to a horizontal direction by conveying the formed band-shaped glass film along a curved conveyance path;
• and
• a horizontal conveyance step of conveying the band-shaped glass film, which has been changed in conveyance direction by the curved conveyance path, in the horizontal direction by a plurality of conveyance devices arranged along a horizontal conveyance path,
• wherein a state of the band-shaped glass film conveyed downward in the vertical direction is detected by a detection unit, and a conveyance speed of each of the plurality of conveyance devices is controlled based on detection data in the detection unit by a speed governor,
• wherein, under a condition that, of the plurality of conveyance devices, a conveyance device of the plurality of conveyance devices located on a most upstream side is defined as an upstream side conveyance device, and a conveyance device of the plurality of conveyance devices on a downstream side of the upstream side conveyance device is defined as a downstream side conveyance device, an upper limit and a lower limit are set to the conveyance speed of the downstream side conveyance device,
• wherein a conveyance speed V1 of the upstream side conveyance device is corrected from a reference speed based on the detection data in the detection unit,
• wherein determination is made on whether or not the conveyance speed V1 of the upstream side conveyance device after the correction falls within a specified speed range, and
• wherein the speed governor comprises a control unit that corrects the conveyance speed of the downstream side conveyance device based on the conveyance speed V1 after the correction when the conveyance speed V1 after the correction falls within the specified speed range, and corrects
• the conveyance speed of the downstream side conveyance device to the upper limit or the lower limit based on an upper limit value or a lower limit value within the specified speed range when the conveyance speed V1 after the correction is outside of the specified speed range.