A radiation image reading device includes: a light scanning unit; a light detection unit. Each of a transmittance when the excitation light reflected from the surface of the recording medium is transmitted through the optical filter and a transmittance when the signal light emitted from the surface of the recording medium at an angle larger than a predetermined angle with respect to a direction perpendicular to the scan line within the detection surface is transmitted through the optical filter is smaller than a transmittance when the signal light emitted from the surface of the recording medium at an angle smaller than the predetermined angle with respect to a direction perpendicular to the scan line within the detection surface is transmitted through the optical filter.

An optical filter including: a substrate; and a dielectric multilayer film laid on or above at least one major surface of the substrate as an outermost layer, in which the substrate includes a resin film including a dye (IR) and a resin, the dye (IR) has a maximum absorption wavelength in a wavelength of 680 to 800 nm in the resin, and the optical filter satisfies specific spectroscopic characteristics.

There is provided an optical filter capable of effectively transmitting ultraviolet light in a wavelength range from 220 nm to 225 nm while suppressing the transmission of ultraviolet light in a wavelength range from 240 nm to 320 nm. An optical filter 1 includes a transparent substrate 2 and a dielectric multilayer film 3 provided on the transparent substrate 2 and containing hafnium oxide. A minimum value of spectral transmittance in a wavelength range from 220 nm to 225 nm is 50% or more with an incident angle of 0 degrees, and a maximum value of spectral transmittance in a wavelength range from 240 nm to 320 nm is 5% or less with an incident angle of 0 degrees.

The invention generally relates to optical filters that provide regulation and/or enhancement of chromatic and luminous aspects of the color appearance of light to human vision, generally to applications of such optical filters, to therapeutic applications of such optical filters, to industrial and safety applications of such optical filters when incorporated, for example, in radiation-protective eyewear, to methods of designing such optical filters, to methods of manufacturing such optical filters, and to designs and methods of incorporating such optical filters into apparatus including, for example, eyewear and illuminants.

The present invention relates to an optically functional absorbing solution composition, infrared absorbing-enhanced glass using same, and an infrared transmitting filter comprising same, the optically functional absorbing solution composition comprising: a resin having a siloxane group substituted at an acrylic group; an organic solvent; and a dye comprising heat resistant dyes and/or non-heat-resistant dyes.

Devices, apparatuses, and methods are disclosed that include a glass or glass ceramic substrate with a bleached region and an unbleached region. Examples include a substrate with a region that transmits IR wavelength light, and a region that is substantially opaque to IR light. Examples include additional opacity in some or all regions to visible wavelength light and/or UV wavelength light.

Provided are: a band-pass filter for which filter characteristics can be improved; and a manufacturing method therefor. A band-pass filter 11, which allows light of a specific wavelength region to pass, includes: a substrate 12 which has light transmitting properties; a first dielectric multilayer film 13 that is provided on a first main surface S1 of the substrate 12; and a second dielectric multilayer film 14 that is provided on a second main surface S2 which is opposite the first main surface S1. The first dielectric multilayer film 13 contains a hydrogenated silicon layer. The second dielectric multilayer film 14 contains a hydrogenated silicon layer.

A system and a method for a nanostructured film including a first layer for reflecting at least a portion of an electromagnetic radiation and a second layer for receiving the remainder of the electromagnetic radiation through the first layer and subsequently reflecting at least a portion of the received electromagnetic radiation through the first layer, wherein two electromagnetic radiations with the same wavelength reflected by the first and second layers respectively are combined to form a strengthened electromagnetic radiation, the wavelength of the strengthened electromagnetic radiation being variable based on the physical property of the first layer.

A filter glass contains >1.1 to 6.0 wt % Li.sub.2O and at least one further component selected from Na.sub.2O and K.sub.2O, and includes the following composition (in wt % based on oxide): 55.0-75.0 P.sub.2O.sub.5, 4.1-8.0 Al.sub.2O.sub.3, 8.0-18.0 CuO, 0-<0.8 V.sub.2O.sub.5, ≤2.0 SiO.sub.2, ≤2.0 F, 0-11.0 Total R′O (R′=Mg, Ca, Sr, Ba, Zn), and 3.0-17.0 Total R.sub.2O (R=Li, Na, K).

A low infrared absorbing lithium glass includes FeO in the range of 0.0005-0.015 wt %, more preferably 0.001-0.010 wt %, and a redox ratio in the range of 0.005-0.15, more preferably in the range of 0.005-010. The glass can be chemically tempered and used to provide a ballistic viewing cover for night vision goggles or scope. A method is provided to change a glass making process from making a high infrared absorbing lithium glass having FeO in the range of 0.02 to 0.04 wt % and a redox ratio in the range of 0.2 to 0.4 to the low infrared absorbing lithium glass by adding additional oxidizers to the batch materials. A second method is provided to change a glass making process from making a low infrared absorbing lithium glass to the high infrared absorbing lithium glass by adding additional reducers to the batch material. In one embodiment of the invention the oxidizer is CeO.sub.2. An embodiment of the invention covers a glass made according to the method.