Abstract: Provided is an ATR element which uses measuring light in a near-infrared region and can precisely determine the state of a substance even if the substance has a low absorption coefficient for the measuring light. An ATR element 10 including: an element main body 11 having a reflective surface 13 continuous in a circumferential direction; an entrance surface 19 through which measuring light DL enters the element main body 11; and an exit surface 21 through which the measuring light DL entering through the entrance surface 19 and reflected off the reflective surface 13 of the element main body 11 exits to the outside, wherein the measuring light DL having entered through the entrance surface 19 follows a spiral passage route while repeatedly reflecting off the reflective surface 13 before exiting through the exit surface 21 toward the outside.

Abstract: The method for detecting rotary speed includes: a step (I) for deeming the difference between input power (P) and loss power (A) to be a first order approximation value (PM1) of the mechanical output of an induction motor, and for obtaining a first approximation value (N1=NS(1?S1)) (NS is the synchronous speed) of the rotary speed from the functional relationship (PM1=?S1) of the output (PM) and slip (S) known for the induction motor; a step (II) for obtaining loss power (B1) based on the value (N1); and a step (III) for deeming a second order approximation value (PM2) of the motor output to be P?(A+B1), and for obtaining a second order approximation value (N2=NS(1?S2)) of the rotary speed from the functional relationship (PM2=?S2) (? is the motor constant) of the output (PM) and slip (S).

Abstract: The method for detecting rotary speed includes: a step (I) for deeming the difference between input power (P) and loss power (A) to be a first order approximation value (PM1) of the mechanical output of an induction motor, and for obtaining a first approximation value (N1=NS(1?S1)) (NS is the synchronous speed) of the rotary speed from the functional relationship (PM1=?S1) of the output (PM) and slip (S) known for the induction motor; a step (II) for obtaining loss power (B1) based on the value (N1); and a step (III) for deeming a second order approximation value (PM2) of the motor output to be P?(A+B1), and for obtaining a second order approximation value (N2=NS(1?S2)) of the rotary speed from the functional relationship (PM2=?S2) (? is the motor constant) of the output (PM) and slip (S).

Abstract: A method is presented for maintaining a plate member in a flat state, including the steps of placing the plate member on a surface of a supporting member, the surface of the supporting member being in a flat state and having at least one hole penetrating through the surface, and sucking air from a back side of the surface of the supporting member to generate an airflow flowing from a front side of the surface towards the back side thereof via the hole so as to retain the plate member on the surface of the supporting member. In this manner, the plate member, such as disc substrates adhered together by using an ultraviolet curable composition, can be accurately maintained in a flat state without damaging the surface thereof.

Abstract: A method for manufacturing discs by bonding two disc substrates using a cationic polymerization type ultraviolet curable composition as an adhesive to produce a disc. The method includes the steps of: applying the cationic polymerization type ultraviolet curable composition onto a part of an adhering surface of one of the two disc substrates; radiating ultraviolet light onto the cationic polymerization type ultraviolet curable composition; bonding the disc substrate to the other disc substrate via the cationic polymerization type ultraviolet curable composition which has been irradiated by the ultraviolet light; and spreading the cationic polymerization type ultraviolet curable composition which is present between the two disc substrates.

Abstract: To cement UV radiation-transmitting substrates to one another without deformation and within a short time, and to cement them together with high efficiency without an aluminum film of an information recording layer melting, according to the invention, a device for bonding discs to one another is provided having a radiant light source which irradiates the discs with radiant light which contains ultraviolet radiation at least once in a flash; a wavelength selector which is placed in the optical path between the radiant light source and the discs at a distance from the discs, which transmits the ultraviolet rays and absorbs light in a range of wavelengths which are absorbed by the UV radiation-transmitting substrates of the discs; a cooling device which admits and discharges cooling air between the radiant light source and the wavelength selector.