A phosphor protection film for protecting phosphors contained in a phosphor layer. The phosphor protection film includes a functional layer, a bulking layer that has a single-layer structure or a laminated structure, and a first vapor deposited layer (gas barrier layer) that has gas barrier properties in this order from outside to inside. The clearance between the functional layer and the first vapor deposited layer in the thickness direction of the phosphor protection film is 45 to 280 μm.

A problem is presented in that conventional photochromic compounds cannot be considered adequate in terms of the colorizing/decolorizing rate and durability, and the production process therefore has many steps. The present invention provides an industrially applicable photochromic compound that has both a rapid colorizing/decolorizing reaction and high durability and can also be synthesized at a low cost. This compound is characterized in that etheric oxygen atoms are bonded to the carbon atoms at position 1 of a pyranoquinazoline (8H-pyrano[3,2-f]quinazoline) skeleton and position 10 of a naphthopyran (3H-naphtho[2,1-b]pyran) skeleton, said compound having photochromic properties and being a photochromic compound that has both a rapid colorizing/decolorizing reaction and high durability. Also provided is an industrially applicable photochromic compound that can be synthesized at a low cost.

A self-luminous display device includes a wavelength selective absorption filter containing a resin and a dye including dye A, which has a main absorption wavelength band (WB) at a wavelength of 390 to 435 nm, a dye B, which has a main absorption WB at a wavelength of 500 to 520 nm, and a dye C, which has a main absorption WB at a wavelength of 580 to 620 nm, and a light emitting diode source, the wavelength selective absorption filter satisfies a definition according to Expression (I): T.sub.min (500 to 520)−T.sub.min (580 to 620)>0%; where T.sub.min indicates a minimum transmittance (%) at the cited wavelength, and a self-luminous display device in which the wavelength selective filter has a specific gas barrier layer directly disposed on at least one surface of the wavelength selective absorption filter.

According to some aspects of the present disclosure, an atomic clock and methods of forming and/or using an atomic clock are disclosed. In one embodiment, an atomic clock includes: a light source configured to illuminate a resonance vapor cell; a narrowband optical filter disposed between the light source and the resonance vapor cell and arranged such that light emitted from the light source passes through the narrowband optical filter and illuminates the resonance vapor cell. The resonance vapor cell is configured to emit a signal corresponding to a hyperfine transition frequency in response to illumination from the light source, and a filter cell is disposed between the light source and the resonance vapor cell and configured to generate optical pumping. An optical detector is configured to detect the emitted signal corresponding to the hyperfine transition frequency.

According to some aspects of the present disclosure, an atomic clock and methods of forming and/or using an atomic clock are disclosed. In one embodiment, an atomic clock includes: a light source configured to illuminate a resonance vapor cell; a narrowband optical filter disposed between the light source and the resonance vapor cell and arranged such that light emitted from the light source passes through the narrowband optical filter and illuminates the resonance vapor cell. The resonance vapor cell is configured to emit a signal corresponding to a hyperfine transition frequency in response to illumination from the light source, and a filter cell is disposed between the light source and the resonance vapor cell and configured to generate optical pumping. An optical detector is configured to detect the emitted signal corresponding to the hyperfine transition frequency.

A method for optical microscopy, including using a first laser beam to excite dye particles in a sample region with light having a first wavelength. A second laser beam with a second wavelength based on the emission spectrum of the excited particles is used to de-excite the excited particles. The first and second beams have first and second respective intensity distributions which are spatially different when co-aligned; the second profile has a minimum where the first has a maximum. The region is once concurrently illuminated with the first and second beams, and an emission signal is detected. For each scanning point, the region is illuminated also with a pulse of the second laser beam or continuously prior to or after illuminating the region of the sample concurrently with both lasers. The illumination with only the second laser beam defines a background signal that is subtracted from the emission signal.

[Problem] A problem is presented in that conventional photochromic compounds cannot be considered adequate in terms of the colorizing/decolorizing rate and durability, and the production process therefore has many steps. The present invention provides an industrially applicable photochromic compound that has both a rapid colorizing/decolorizing reaction and high durability and can also be synthesized at a low cost.

[Solution] This compound is characterized in that etheric oxygen atoms are bonded to the carbon atoms at position 1 of a pyranoquinazoline (8H-pyrano[3,2-f]quinazoline) skeleton and position 10 of a naphthopyran (3H-naphtho[2,1-b]pyran) skeleton, said compound having photochromic properties and being a photochromic compound that has both a rapid colorizing/decolorizing reaction and high durability. Also provided is an industrially applicable photochromic compound that can be synthesized at a low cost.

Provided is an imaging device including a light receiving portion including a plurality of photoelectric conversion elements arranged in a two-dimensional manner, and a spectral filter including a storage portion that stores a substance composed of a fluid or a gas, an inflow portion through which the substance flows into the storage portion, and an outflow portion through which the substance flows out from the storage portion, the spectral filter having a spectral characteristic corresponding to a refractive index of the substance, the spectral filter being each provided for one or more of the photoelectric conversion elements.

According to some aspects of the present disclosure, an atomic clock and methods of forming and/or using an atomic clock are disclosed. In one embodiment, an atomic clock includes: a light source configured to illuminate a resonance vapor cell; a narrowband optical filter disposed between the light source and the resonance vapor cell and arranged such that light emitted from the light source passes through the narrowband optical filter and illuminates the resonance vapor cell. The resonance vapor cell is configured to emit a signal corresponding to a hyperfine transition frequency in response to illumination from the light source, and a filter cell is disposed between the light source and the resonance vapor cell and configured to generate optical pumping. An optical detector is configured to detect the emitted signal corresponding to the hyperfine transition frequency.

A color control member includes a light control layer including quantum dots, a color filter layer disposed on the light control layer, and a low refractive layer disposed between the color filter layer and the light control layer. The low refractive layer includes a base resin, a plurality of non-hollow inorganic particles dispersed in the base resin and of which inner portions are filled. A weight percent of the base resin is in a range of about 40 wt % to about 45 wt % with respect to a total weight of the low refractive layer, and a weight percent of the non-hollow inorganic particles is in a range of about 40 wt % to about 45 wt % with respect to the total weight of the low refractive layer. The color control member including the low refractive layer has excellent reliability.