US 12,216,274 B2
Method and program for predicting bending in optical products
Muneo Sugiura, Okazaki (JP); Koichi Tamura, Okazaki (JP); and Takuro Yoshida, Okazaki (JP)
Assigned to Tokai Optical Co., Ltd., Okazaki (JP)
Filed by TOKAI OPTICAL CO., LTD., Okazaki (JP)
Filed on Jul. 12, 2021, as Appl. No. 17/305,611.
Application 17/305,611 is a continuation of application No. PCT/JP2019/050662, filed on Dec. 24, 2019.
Claims priority of application No. 2019-006368 (JP), filed on Jan. 17, 2019.
Prior Publication US 2021/0341733 A1, Nov. 4, 2021
Int. Cl. G02B 27/00 (2006.01); G02B 1/10 (2015.01); G06F 30/20 (2020.01); G06F 111/10 (2020.01)
CPC G02B 27/0012 (2013.01) [G02B 1/10 (2013.01); G06F 30/20 (2020.01); G06F 2111/10 (2020.01)] 8 Claims
OG exemplary drawing
 
1. A computer implemented optical product bending prediction program configured to predict a bending δ of a substrate having a film by execution thereof by a computer,
wherein the computer includes a non-transitory, computer-readable storage medium storing the optical product bending prediction program and an integrated film designing program, and control means capable of referring to the non-transitory computer-readable storage medium to execute the optical product bending prediction program and the integrated film designing program stored therein,
wherein the optical product bending prediction program stored in the non-transitory, computer-readable medium includes the following Expressions (A1) to (I), in which a is set as a first fitting parameter and Td is set as a second fitting parameter, the fitting parameters having been optimized for each coating condition using a plurality of samples,
wherein the control means is configured to execute the optical product bending prediction program to perform calculations to predict the bending δ of the substrate having the film using the Expressions (A1) to (I),

OG Complex Work Unit Math
wherein σint is intrinsic stress, Ef is a Young's modulus of a multilayer film, EH is a Young's modulus of a high refractive index layer, EL is a Young's modulus of a low refractive index layer, vf is a Poisson's ratio of the multilayer film, vH is a Poisson's ratio of the high refractive index layer, vL is a Poisson's ratio of the low refractive index layer, αf is a coefficient of linear expansion of the multilayer film, αH is a coefficient of linear expansion of the high refractive index layer, αL is a coefficient of linear expansion of the low refractive index layer, αs is a coefficient of linear expansion of the substrate, T is a room temperature, d is a film thickness, b is a thickness of the substrate, 1 is a radius of the substrate, Es is a Young's modulus of the substrate, vs is a Poisson's ratio of the substrate, dH is a total film thickness of the high refractive index layer, dL is a total film thickness of the low refractive index layer, σH is intrinsic stress of the high refractive index layer, and σL is intrinsic stress of the low refractive index layer, and
wherein the film designing program stored in the non-transitory, computer-readable medium, automatically passes values determined by the film designing program to the bending prediction program, whereby an accurate bending δ of the substrate can be determined during or at the completion of executing the film designing program.