Device and method for reducing power consumption in display devices

• US 9,691,334 B2
• Filed: 10/28/2013
• Issued: 06/27/2017
• Est. Priority Date: 11/07/2012
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kanzaki, Eisuke, Nakayama, Yasutomo D.
• Primary Examiner(s): Tryder, Gregory J
• Assistant Examiner(s): Le, Michael
• Application Number:
  US14/065,033
• Publication Number:
  US 20140125690A1
• Time in Patent Office: 1,338 Days
• Field of Search: 345581, 345600
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• CPC Class Codes: G09G 2320/0606 Manual adjustment
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 2370/027 Arrangements and methods specific for the display of internet documents
• CPC Class Codes: G09G 2370/042 for monitor identification
• CPC Class Codes: G09G 3/36 using liquid crystals
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/10 Intensity circuits

Abstract

Devices and methods are disclosed that reduce the amount of power consumed by an existing display device irrespective of the display mode. One such method includes recognizing a display mode related to light and dark when no voltage is applied to the display device. The method also includes determining a shift direction for the values of an image based on the recognized display mode so that power consumption is reduced in the display device. The method further includes determining a shift amount for the values of the image in accordance with a predetermined process, and converting the values of the image to be converted in the determined shift direction in accordance with the determined shift amount.

Claims

1. A power consumption reducing device of a display device, the device comprising:

a recognizing unit configured to recognize a display mode related to light and dark when no voltage is applied to the display device;

a shift direction determining unit configured to determine a shift direction for the values of an image based on the display mode recognized by the recognizing unit so that power consumption is reduced in the display device;

a shift amount determining unit configured to determine a shift amount for the values of the image based on a first user operation that specifies an allowable level for each value of the image related to change in appearance of the image and based on the values of the image to be converted,

wherein a shift S is determined in a white direction using a first calculation of cV=[V+S], and in a black direction using a second calculation of cV=[V−

S],

wherein the shift S is the shift amount, V is a sub-pixel value before a conversion, and cV is a sub-pixel value after the conversion,

wherein the shift S applies a maximum value when one or both of the first and second calculations produce a value greater than the maximum value and applies a minimum value when one or both of the first and second calculations produce a value smaller than the minimum value; and

a converting unit configured to convert the values of the image to be converted in the shift direction determined by the first determining unit in accordance with the shift amount determined by the second determining unit and changing the settings of the cascading style sheet (CSS) used by the image to be converted; and

an acquiring unit configured to acquire association information for associating a range of a density of the image with the allowable level related to change in appearance of the image based on a second user operation that specifies an allowable level for each image density range.

2. The device of claim 1, wherein the shift direction determining unit determines that the shift direction is in the direction in which the image becomes brighter in response to the recognizing unit recognizing a first mode in which the screen is light when no voltage is applied, and determines that the shift direction is in the direction in which the image becomes darker in response to the recognizing unit recognizing a second mode in which the screen is dark when no voltage is applied.

3. A device for reducing power consumption in a display device, the device comprising:

a recognizing unit configured to determine whether a display mode of the display device is a normally white mode or a normally black mode;

a shift direction determining unit configured to determine;

that a shift direction for the density of an image is in the direction of lower density in response to the determination by the determining unit that the display mode is the normally white mode, and

that the shift direction for the density of the image is in the direction of higher density in response to the determination by the determining unit that the display mode is the normally black mode;

an acquiring unit configured to acquire association information for associating a range of the density of the image with an allowable level related to change in appearance of the image based on a user operation that specifies the allowable level for each image density range;

a calculating unit configured to calculate the density of the image to be converted by determining the average values of an R value, G value and B value in the image to be converted;

a shift amount determining unit configured to determine a shift amount for the density of the image to be converted based on the allowable level associated by the association information with a range including the density of the image to be converted as calculated by the calculating unit and based on the values of the image to be converted,

wherein a shift S is determined in a white direction using a first calculation of cV=[V+S], and in a black direction using a second calculation of cV=[V−

S],

wherein the shift S is the shift amount, V is a sub-pixel value before a conversion, and cV is a sub-pixel value after the conversion,

wherein the shift S applies a maximum value when one or both of the first and second calculations produce a value greater than the maximum value and applies a minimum value when one or both of the first and second calculations produce a value smaller than the minimum value; and

a converting unit configured to convert the density of the image to be converted in the shift direction determined by the shift direction determining unit by the shift amount determined by the shift amount determining unit and by changing the settings related to the colors in the cascading style sheet (CSS) used by the image to be converted.

4. The device of claim 3, wherein the shift direction determining unit determines that the shift direction is in the direction in which the image becomes brighter in response to the recognizing unit recognizing a first mode in which the screen is light when no voltage is applied, and determines that the shift direction is in the direction in which the image becomes darker in response to the recognizing unit recognizing a second mode in which the screen is dark when no voltage is applied.

5. A method for reducing power consumption in a display device, the method comprising:

recognizing a display mode related to light and dark when no voltage is applied to the display device;

determining a shift direction for the values of an image based on the recognized display mode so that power consumption is reduced in the display device;

determining a shift amount for the values of the image in accordance with a predetermined process based on a user operation that specifies an allowable level for each value of the image related to change in appearance of the image and based on the values of the image to be converted,

wherein a shift S is determined in a white direction using a first calculation of cV=[V+S], and in a black direction using a second calculation of cV=[V−

S],

wherein the shift S is the shift amount, V is a sub-pixel value before a conversion, and cV is a sub-pixel value after the conversion,

wherein the shift S applies a maximum value when one or both of the first and second calculations produce a value greater than the maximum value and applies a minimum value when one or both of the first and second calculations produce a value smaller than the minimum value;

converting the values of the image to be converted in the determined shift direction in accordance with the determined shift amount; and

acquiring association information for associating a range of a density of the image with the allowable level related to change in appearance of the image based on a user operation that specifies the allowable level for each image density range.

6. The method of claim 5, wherein the determining that the shift direction is in the direction in which the image becomes brighter is in response to recognizing a first mode in which the screen is light when no voltage is applied, and the determining that the shift direction is in the direction in which the image becomes darker in response to a second mode in which the screen is dark when no voltage is applied.