Display device and signal processing method

Patent metadata

Field	Value
Publication number	US-2019180701-A1
Application number	US-201716321850-A
Country	US
Kind code	A1
Filing date	Sep 4, 2017
Priority date	Sep 9, 2016
Publication date	Jun 13, 2019
Grant date	—

Abstract

A display device is a display device having a display that displays an image based on a received image signal. This display device includes: a memory that stores maximum luminance information regarding maximum luminance that the display can display; a determiner that determines whether the image signal is an HDR image signal specified by relative luminance; a first converter that, when the determiner determines that the image signal is the HDR image signal specified by the relative luminance, subjects luminance information obtained from the image signal to nonlinear conversion based on a luminance characteristic of the display; and a second converter that converts the luminance information that has been subjected to the nonlinear conversion by the first converter such that the display displays an image at increased luminance within a luminance range determined in accordance with the maximum luminance information.

First claim

1 . A display device having a display that displays an image based on a received image signal, the display device comprising:
a memory that stores maximum luminance information regarding maximum luminance that the display can display; a determiner that determines whether the image signal is a high dynamic range (HDR) image signal specified by relative luminance; a first converter that, when the determiner determines that the image signal is the HDR image signal specified by the relative luminance, subjects luminance information obtained from the image signal to nonlinear conversion based on a luminance characteristic of the display; and a second converter that converts the luminance information that has been subjected to the nonlinear conversion by the first converter such that the display displays an image at increased luminance within a luminance range determined in accordance with the maximum luminance information.

2 . The display device according to claim 1 , wherein the second converter converts the luminance information that has been subjected to the nonlinear conversion by the first converter such that the display displays an image at increased luminance within the luminance range and within a high luminance range, luminance being higher in the high luminance range than in the luminance range, different conversion methods being used for the luminance range and the high luminance range.

3 . The display device according to claim 2 , wherein the second converter converts the luminance information that has been subjected to the nonlinear conversion by the first converter, by multiplying the luminance information in the luminance range by a gain more than 1 and such that the luminance information before the nonlinear conversion and the luminance information after the nonlinear conversion have a linear relationship within the high luminance range.

4 . The display device according to claim 2 , wherein the luminance range is a luminance range determined from the maximum luminance information corrected using information received from a user.

5 . The display device according to claim 2 , wherein the second converter sets a maximum value in the luminance range to a lower value as maximum luminance used in the image signal has a larger value.

6 . The display device according to claim 2 , wherein the second converter decreases a maximum value in the luminance range as a white area in the image signal increases.

7 . The display device according to claim 1 , wherein the second converter sets a maximum value in the luminance range to a higher value as average luminance obtained from the image signal has a larger value.

8 . The display device according to claim 1 , wherein the second converter converts the luminance information that has been subjected to the nonlinear conversion by the first converter such that the display displays an image at further increased luminance within at least a partial range contained in the luminance range as surrounding illuminance increases.

9 . A signal processing method performed by a display device having a display that displays an image based on a received image signal, the signal processing method comprising:
determining whether the image signal is a high dynamic range (HDR) image signal specified by relative luminance; when the determination is made that the image signal is the HDR image signal specified by the relative luminance, subjecting luminance information obtained from the image signal to nonlinear conversion based on a luminance characteristic of the display; and converting the luminance information that has been subjected to the nonlinear conversion such that the display displays an image at increased luminance within a luminance range determined in accordance with maximum luminance information regarding maximum luminance that the display can display.

10 . The display device according to claim 3 , wherein the luminance range is a luminance range determined from the maximum luminance information corrected using information received from a user.

11 . The display device according to claim 3 , wherein the second converter sets a maximum value in the luminance range to a lower value as maximum luminance used in the image signal has a larger value.

12 . The display device according to claim 3 , wherein the second converter decreases a maximum value in the luminance range as a white area in the image signal increases.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Nakanishi Hirokazu
• Higashida Takashi

Classifications

• H04N23/951

  by using two or more images to influence resolution, frame rate or aspect ratio · CPC title

• G09G3/20

  for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters} · CPC title

• G09G5/10

  Intensity circuits · CPC title

• H04N5/20

  Circuitry for controlling amplitude response · CPC title

• G09G2320/0646

  Modulation of illumination source brightness and image signal correlated to each other · CPC title