Display device and head-mounted display

Patent metadata

Field	Value
Publication number	US-10775627-B2
Application number	US-201816497813-A
Country	US
Kind code	B2
Filing date	Mar 30, 2018
Priority date	Mar 30, 2017
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

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.

First claim

The invention claimed is:

1. A display device comprising: a display panel configured to display an image; a lighting device configured to supply light to the display panel for image display; at least one light source included in the lighting device, the at least one light source including at least a blue light emitting element configured to emit blue light and a red phosphor configured to emit red light when excited by the blue light from the blue light emitting element; a lighting controller configured to control driving of the at least one 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; a complex fluoride red phosphor constituting the red phosphor and having a content ratio in a range from 50% to 85% inclusive; and a nitride red phosphor constituting the red phosphor and having a content ratio in a range from 15% to 50% inclusive.

2. The display device according to claim 1 , wherein
the content ratio of the complex fluoride red phosphor is in a range from 75% to 85% inclusive, and
the content ratio of the nitride red phosphor is in a range from 15% to 25% inclusive.

3. The display device according to claim 1 , wherein
the content ratio of the complex fluoride red phosphor is 85%, and
the content ratio of the nitride red phosphor is 15%.

4. The display device according to claim 1 , wherein
the content ratio of the complex fluoride red phosphor is 75%, and
the content ratio of the nitride red phosphor is 25%.

5. The display device according to claim 1 , wherein the complex fluoride red phosphor is a fluoride complex red phosphor with manganese used as an activator.

6. The display device according to claim 1 , wherein the nitride red phosphor is an alkaline-earth silicon nitride red phosphor with europium used as an activator.

7. The display device according to claim 1 , wherein the lighting controller is configured to control the driving of the at least one light source so that the turn-off period starts in synchronization with the start of the one-frame display period and the turn-on period starts after the end of the turn-off period and ends in synchronization with the end of the one-frame display period.

8. The display device according to claim 1 , further comprising a panel controller configured to control driving of the display panel, wherein
the display panel includes a plurality of pixels arranged in rows and columns,
the panel controller is configured to sequentially scan lines of the pixels along a column direction during the one-frame display period, each of the lines of the pixels including a plurality of the pixels arranged in a row direction,
the at least one light source includes a plurality of light sources configured to selectively supply light to the lines of the pixels, and
the lighting controller is configured to control driving of the plurality of light sources in synchronization with driving of the lines of the pixels to which light are supplied so that the turn-on period and the turn-off period are included in a period in which the lines of the pixels are being driven during scanning of the lines of the pixels in sequence by the panel controller.

9. A head-mounted display comprising at least:
the display device according to claim 1 ;
a lens through which an image of a displayed image on the display device is formed in an eye of a user; and
a head mounter to be mounted on a head of the user, the head mounter including the display device and the lens.

Assignees

• Sharp Kk
• Nichia Corp

Inventors

• Hayashi Tokumi
• Hatsuda Kenichi
• Akagawa Seitaro
• Morikawa Takeshi

Classifications

• C09K11/675 Primary

  with alkali or alkaline earth metals · CPC title

• C09K11/77348

  Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides · CPC title

• H10H20/8512

  Wavelength conversion materials · CPC title

• G02F1/133614

  using photoluminescence, e.g. phosphors illuminated by UV or blue light · CPC title

• G02F1/133601

  for spatial active dimming · CPC title