SENSOR DEVICE, LIQUID CRYSTAL DISPLAY DEVICE, SENSING METHOD AND PROGRAM

• US 20160111048A1
• Filed: 05/29/2013
• Published: 04/21/2016
• Est. Priority Date: 05/29/2013
• Status: Active Grant

• Current Assignee: Sharp NEC Display Solutions, Ltd. (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: NEC Display Solutions, Ltd. (NEC Corporation)
• Inventors: MATSUI, Katsuyuki
• Granted Patent: US 9,530,360 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01J 1/0228 Control of working procedures; Failure detection; Spectral bandwidth calculation
• CPC Class Codes: G01J 1/42 using electric radiation detectors optical or mechanical part G01J1/04; by comparison with a reference light or electric value G01J1/10
• CPC Class Codes: G01J 1/4209 Photoelectric exposure meters for determining the exposure time in recording or reproducing
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: H05B 45/12 using optical feedback
• CPC Class Codes: H05B 45/14 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 45/22 using optical feedback
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A sensor device includes: a light sensor that acquires a first light quantity measurement value that is proportional to a light quantity of a backlight and a first measurement time; a light quantity target value calculating unit that calculates a light quantity target value based on a user setting for the backlight; and a measurement time calculating unit that calculates a second measurement time for when the light sensor acquires a second light quantity measurement value a next time, based on the acquired first light quantity measurement value and the light quantity target value.

Claims

1. A sensor device comprising:

a light sensor that acquires a first light quantity measurement value that is proportional to a light quantity of a backlight and a first measurement time;

a light quantity target value calculating unit that calculates a light quantity target value based on a user setting for the backlight; and

a measurement time calculating unit that calculates a second measurement time for when the light sensor acquires a second light quantity measurement value a next time, based on the acquired first light quantity measurement value and the light quantity target value.

2. The sensor device according to claim 1, further comprising:

a normalizing unit that divides the acquired first light quantity measurement value by the first measurement time, to obtain a normalized light quantity measurement value; and

a light quantity reference value setting unit that calculates an absolute value of a difference between the normalized light quantity measurement value and the light quantity target value,

wherein the measurement time calculating unit sets the second measurement time in such a manner that the second measurement time in a case where the absolute value exceeds a light quantity threshold;

becomes shorter than the second measurement time in a case where the absolute value falls below the light quantity threshold.

3. The sensor device according to claim 1, further comprising:

a normalizing unit that divides the acquired first light quantity measurement value by the first measurement time, to obtain a normalized light quantity measurement value; and

a light quantity reference value setting unit that sets a light quantity reference value based on the normalized light quantity measurement value and the light quantity target value, the light quantity reference value being an index of a value acquired as the second light quantity measurement value,

wherein the measurement time calculating unit calculates the second measurement time based on the normalized light quantity measurement value and the light quantity reference value.

4. The sensor device according to claim 3, wherein

the light quantity reference value setting unit calculates an absolute value of a difference between the normalized light quantity measurement value and the light quantity target value,

the light quantity reference value setting unit sets the light quantity reference value as a first reference value when the absolute value exceeds the light quantity threshold,

the light quantity reference value setting unit sets the light quantity reference value to a second reference value when the absolute value falls below the light quantity threshold, the second reference value being larger than the first reference value, and

the measurement time calculating unit calculates, as the second measurement time, a value having a positive correlation with the light quantity reference value that are set as the first reference value or the second reference value.

5. The sensor device according to claim 4, wherein

the light sensor acquires the first light quantity measurement value for each color of at least two colors,

the normalizing unit divides the acquired first light quantity measurement value for each color by the first measurement time, to obtain the normalized light quantity measurement value for each color,

the measurement time calculating unit adds the normalized light quantity measurement value for each color, to obtain a light quantity measurement total value, and

the measurement time calculating unit divides the light quantity reference value that is set as the first reference value or the second reference value by the light quantity measurement total value, to obtain a first value as the second measurement time.

6. The sensor device according to claim 5, further comprising:

an upper and lower limiter that resets the second measurement time as an upper limit when the first value exceeds the upper limit, the upper and lower limiter resetting the second measurement time as a lower limit when the first value falls below the lower limit.

7. A liquid crystal display device comprising:

the sensor device according to claim 1; and

a backlight control unit that adjusts a brightness of the backlight, based on the first light quantity measurement value acquired by the light sensor.

8. A sensing method comprising:

acquiring a first light quantity measurement value that is proportional to a light quantity of a backlight and a first measurement time;

calculating a light quantity target value based on a user setting for the backlight; and

calculating a second time measurement time for when a second light quantity measurement value is acquired a next time, based on the acquired first light quantity measurement value and the light quantity target value.

9. A non-transitory computer readable recording medium storing a program that causes a computer of a sensor device including a light sensor that acquires a first light quantity measurement value that is proportional to a light amount of a backlight and a first measurement time, to execute:

calculating a light quantity target value based on a user setting for the backlight; and

calculating a second measurement time for when the light sensor acquires a second light quantity measurement value a next time, based on the acquired first light quantity measurement value and the light quantity target value.