A process for preparing a population of coated phosphor particles is presented. The process includes combining particles of a phosphor of formula I: A.sub.x [MF.sub.y]:Mn.sup.4+ with a first solution including a compound of formula II: A.sub.x[MF.sub.y] to form a suspension, where A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is an absolute value of a charge of the [MF.sub.y] ion; and y is 5, 6 or 7. The process further includes combining a second solution including a source A.sup.+ ions with the suspension.

To provide a semiconductor light emitting device which is capable of accomplishing a broad color reproducibility for an entire image without losing brightness of the entire image. A light source provided on a backlight for a color image display device has a semiconductor light emitting device comprising a solid light emitting device to emit light in a blue or deep blue region or in an ultraviolet region and phosphors, in combination. The phosphors comprise a green emitting phosphor and a red emitting phosphor. The green emitting phosphor and the red emitting phosphor are ones, of which the rate of change of the emission peak intensity at 1000 C to the emission intensity at 25 C., when the wavelength of the excitation light is 400 nm or 455 nm, is at most 40%.

A red phosphor comprising a first red phosphor and a second red phosphor having adjustable wavelength. The first red phosphor is made from a substance having structure formula M.sub.2AX.sub.6:Mn.sup.4+, wherein the element M is selected from Li, Na, K, Rb or Cs, the element A is selected from Ti, Si, Ge or Zr, and the element X is selected from F, Cl or Br; the ratio of the second red phosphor to the red phosphor ranges from 0.01% to 15%. Further provided is a white LED and a backlight module. The adjustably colored points of a device including M.sub.2AX.sub.6:Mn.sup.4+ are achieved by adding a second red phosphor having various wavelength to the red phosphor including M.sub.2AX.sub.6:Mn.sup.4+ whose emission wavelength and spectral shape cannot be adjusted. The device can enable full range of colored points with hardly any reduction of the NTSC color gamut.

An LED-filament includes a light-transmissive substrate; a first array of LED chips on a front face of the substrate; a second array of LED chips on the front face of the substrate; a first photoluminescence arrangement covering the first array of LED chips; and a second photoluminescence arrangement covering the second array of LED chips; where the first array of LED chips and the first arrangement generate light of a first color temperature and the second array of LED chips and the second arrangement generate light of a second color temperature.

A display device includes a display panel, a lighting device, at least one light source, a lighting controller, a complex fluoride red phosphor, and a nitride red phosphor. The one light source includes a blue light emitting element and a red phosphor configured to emit red light when excited by the blue light from the blue light emitting element. The lighting controller is configured to control driving of the light source in synchronization with the image display by the display panel so that a one-frame display period in the display panel includes a turn-on period and a turn-off period. The complex fluoride red phosphor constitutes the red phosphor and has a content ratio in a range from 50% to 85% inclusive. The nitride red phosphor constitutes the red phosphor and has a content ratio in a range from 15% to 50% inclusive.

There is provided a display backlight (604), including an excitation source (644) for generating blue light (650); and a wavelength converter (654) being a unitary construction including a combination of a wavelength selective filter layer (658) bonded to a photoluminescence layer (660), where the photoluminescence layer (658) includes a green photoluminescence material and a red photoluminescence material; and where the wavelength selective filter layer (658) is transmissive to blue light and reflective to green and red light.

A process for preparing a population of coated phosphor particles is presented. The process includes combining particles of a phosphor of formula I: A.sub.x [MF.sub.y]:Mn.sup.4+ with a first solution including a compound of formula II: A.sub.x[MF.sub.y] to form a suspension, where A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is an absolute value of a charge of the [MF.sub.y] ion; and y is 5, 6 or 7. The process further includes combining a second solution including a source A.sup.+ ions with the suspension.

To provide a semiconductor light emitting device which is capable of accomplishing a broad color reproducibility for an entire image without losing brightness of the entire image. A light source provided on a backlight for a color image display device has a semiconductor light emitting device comprising a solid light emitting device to emit light in a blue or deep blue region or in an ultraviolet region and phosphors, in combination. The phosphors comprise a green emitting phosphor and a red emitting phosphor. The green emitting phosphor and the red emitting phosphor are ones, of which the rate of change of the emission peak intensity at 100 C. to the emission intensity at 25 C., when the wavelength of the excitation light is 400 nm or 455 nm, is at most 40%.

Provided is a fluoride phosphor that has a good external quantum efficiency and is suitable for stably producing white LEDs. The fluoride phosphor has a composition represented by a general formula (1) and a repose angle of 30 or more and 60 or less. general formula: A.sub.2M.sub.(1-n)F.sub.6:Mn.sup.4+.sub.n (1), wherein 0<n0.1, the element A is one or more alkali metal elements including at least K, and the element M is a simple substance of Si, a simple substance of Ge, or a combination of Si and one or more elements selected from the group consisting of Ge, Sn, Ti, Zr, and Hf.

A display device includes a display panel, a lighting device, at least one light source, a lighting controller, a complex fluoride red phosphor, and a nitride red phosphor. The one light source includes a blue light emitting element and a red phosphor configured to emit red light when excited by the blue light from the blue light emitting element. The lighting controller is configured to control driving of the light source in synchronization with the image display by the display panel so that a one-frame display period in the display panel includes a turn-on period and a turn-off period. The complex fluoride red phosphor constitutes the red phosphor and has a content ratio in a range from 50% to 85% inclusive. The nitride red phosphor constitutes the red phosphor and has a content ratio in a range from 15% to 50% inclusive.