Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
COLOR CALIBRATION AND ADAPTATION DEVICE
Document Type and Number:
WIPO Patent Application WO/2024/019720
Kind Code:
A1
Abstract:
A color calibration and adaptation device is mountable at an edge of a display device and rotatable between a calibration position in which a surface thereof is adjacent to a display surface of the display device and an adaptation position in which the surface thereof is not adjacent to the display surface. The color calibration and adaptation device includes a color sensor exposed at the surface of the color calibration and adaptation device. The color sensor is operable in calibration position to measure display light emitted by the display device at the display surface to calibrate the display device. The color sensor is operable in the adaptation position to measure ambient light of an environment of the display device to adaptatively adjust the display device.

Inventors:
CHU CHIA HUNG (TW)
WU CHUN-YING (TW)
CHUANG CHIA-WEN (TW)
CHEN HUNG-MING (BR)
Application Number:
PCT/US2022/037804
Publication Date:
January 25, 2024
Filing Date:
July 21, 2022
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
HEWLETT PACKARD DEVELOPMENT CO (US)
International Classes:
G09G3/20
Foreign References:
JP2003241729A2003-08-29
US6674436B12004-01-06
Attorney, Agent or Firm:
DAUGHERTY, Raye, L. et al. (US)
Download PDF:
Claims:
We claim:

1 . A color calibration and adaptation device comprising: a housing permanently or removably mountable at an edge of a display device and rotatable between a calibration position in which a surface of the housing is adjacent to a display surface of the display device and an adaptation position in which the surface of the housing is not adjacent to the display surface; and a color sensor exposed at the surface of the housing, operable in calibration position to measure display light emitted by the display device at the display surface to calibrate the display device, and operable in the adaptation position to measure ambient light of an environment of the display device to adaptatively adjust the display device.

2. The color calibration and adaptation device of claim 1 , further comprising: a hinge mount to hingeably mount the housing at the edge of the display device and permit rotation of the housing between the calibration position and the adaptation position.

3. The color calibration and adaptation device of claim 1 , further comprising: a camera device exposed at the surface of the housing to capture images in front of the display surface in the adaptation position.

4. The color calibration and adaptation device of claim 3, further comprising either: a microphone device exposed at the surface of the housing to record first audio within the environment of the display device; a speaker device exposed at any external surface or external surfaces of the housing to output second audio within the environment; or both the microphone device and the speaker device.

5. The color calibration and adaptation device of claim 1 , further comprising: a brightness sensor exposed at the surface of the housing, operable in the calibration position to measure display brightness of the display light to calibrate the display device, and operable in the adaptation position to measure ambient brightness of the environment to adaptatively adjust the display device, wherein the brightness sensor either is integrated as part of the color sensor or is separate from the color sensor.

6. The color calibration and adaptation device of claim 1 , further comprising: an orientation sensor to detect a current position of the housing as the calibration position or the adaptation position.

7. The color calibration and adaptation device of claim 1 , wherein the color sensor comprises either: a red-green-blue-white (RGBW) color sensor to measure color in a red- green-blue (RGB) color space and white color temperature; or an XYZ color sensor to measure color sensor to measure color in a device-independent XYZ color space and white color temperature.

8. A non-transitory computer-readable data storage medium storing program code executable by a processor to perform processing comprising: in response to determining that a surface of a color calibration and adaptation device at which a color sensor is exposed is adjacent to a display surface of a display device, calibrating the display device based on display light emitted by the display device at the display surface as measured by the color sensor; and in response to determining that the surface of the color calibration and adaptation device is not adjacent to the display surface, adaptively adjusting the display device based on ambient light of an environment of the display device as measured by the color sensor.

9. The non-transitory computer-readable data storage medium of claim 8, wherein calibrating the display device comprises: causing the display device to emit specified colors and brightnesses of the display light at the display surface; measuring the specified colors and brightnesses of the display light using the color sensor; and adjusting how the display device is to subsequently emit the display light based on a comparison between the specified colors and brightnesses as measured and as expected to be measured.

10. The non-transitory computer-readable data storage medium of claim 9, wherein adjusting how the display device is to subsequently emit the display light comprises: adjusting either or both of a white point and a brightness of the display device.

11 . The non-transitory computer-readable data storage medium of claim 8, wherein adaptively adjusting the display device comprises: measuring a color temperature of the ambient light of the environment; and adjusting a color temperature of the display device to match the color temperature of the ambient light.

12. The non-transitory computer-readable data storage medium of claim 8, wherein adaptively adjusting the display device comprises: measuring a brightness of the ambient light of the environment; and adjusting a brightness of the display of the display device in correspondence with the brightness of the ambient light.

13. A display device comprising: a housing having a display surface; a display assembly to emit display light at the display surface in correspondence with a display signal; a color sensor rotatable between a calibration position in which the color sensor is adjacent to the display surface and an adaptation position in which the color sensor is not adjacent to the display surface; and a control circuit to calibrate the display assembly based on the display light emitted by the display assembly as measured by the color sensor in the calibration position, and to adaptively adjust the display assembly based on ambient light of an environment of the display device as measured by the color sensor in the adaptation position.

14. The display device of claim 13, wherein the control circuit is to calibrate the display assembly by adjusting either or both of a white point and a brightness of the display assembly based on the display light as measured by the color sensor in the calibration position.

15. The display device of claim 13, wherein the control circuit is to either: adjust a color temperature of the display assembly to match a color temperature of the ambient light as measured by the color sensor in the adaptation position; adjust a brightness of the display assembly in correspondence with a brightness of the ambient light as measured by the color sensor in the adaptation position; or both adjust the color temperature of the display assembly to match the color temperature of the ambient light and adjust the brightness of the display assembly in correspondence with the brightness of the ambient light.

Description:
COLOR CALIBRATION AND ADAPTATION DEVICE

BACKGROUND

[0001] Electronic devices include consumer, industrial, and business devices, such as computing devices, peripheral devices, and other types of electronic devices. Electronic devices often include displays, or can be connected to standalone display devices, by which they information is displayed to users. The displays can include large or small flat-panel displays (FPDs), including liquid crystal displays (LCDs) and organic light-emitting diode (OLED) displays, among other types of displays.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] FIGs. 1 A and 1 B are side-view diagrams of an example color calibration and adaptation device for a display device in calibration and adaptation positions, respectively.

[0003] FIG. 2 is a diagram of an example non-transitory computer- readable data storage medium storing program code for using a color calibration and adaptation device to calibrate and adaptively adjust a display device.

[0004] FIG. 3 is a flowchart of an example method for calibrating a display device using a color calibration and adaptation device in a calibration position.

[0005] FIG. 4 is a flowchart of an example method for adaptively adjusting a display device using a color calibration and adaptation device in an adaptation position. [0006] FIGs. 5A and 5B are diagrams of an example color calibration and adaptation device that is permanently mountable to and part of a display device and that is removably mountable to and separate from a display device, respectively.

[0007] FIG. 6 is a front-view diagram of an example color calibration and adaptation device for a display device.

DETAILED DESCRIPTION

[0008] As noted in the background, electronic devices often have displays, or can be connected to a standalone display device, by which information is displayed to users. A display device can be considered as an electronic device that has a display. Therefore, a display device can be a standalone display device for connection to another device, such as a computing device like a computer. A display device can also be a computing device or other electronic device, such as a laptop or notebook computer or an all-in-one (AIO) desktop computer, which includes a display.

[0009] A display device can be calibrated so that the device accurately displays images. The calibration of a display device may calibrate the white point of the display, which is a set of tristimulus values or chromaticity coordinates that define the color white in image reproduction, as well as the brightness of the display, which is the light intensity at which images are displayed. Calibrating the display device is independent of the environment in which the device is operating, and thus is independent of the ambient light of the environment in which the device is being used. [0010] A display device can also be adaptively adjusted to accommodate the environment in which the device is being used. The adaptive adjustment of a display device may adaptively adjust the color temperature of the display to match the color temperature of the ambient light of the environment in which the device is being used. The adaptive adjustment may also adaptively adjust the brightness of the display in correspondence with the brightness of the ambient light of the environment, such that brightness is reduced with darker environments and increased with brighter environments. Adjusting the display device to adapt the device to its environment is independent of calibration of the device, and may occur periodically or continuously after calibration, for instance.

[0011] Color temperature is a characteristic of visible light that is measured in kelvins (K), and can differ depending on the environment in which the display device is being used. If the display device is being used under natural light conditions by a window during daytime or other daylight conditions, the color temperature of the ambient light may be 5500-6500 K as one example. If the device is being used in a room illuminated by incandescent or halogen light or another warm light source, the color temperature of the ambient light may be 2700-3000K as one example. If the device is being used in a room illuminated by fluorescent light or another cool light source, the color temperature of the ambient light may be 3000-4500K as one example.

[0012] Techniques described herein provide for a device that can be used for both calibrating a display device and adaptively adjusting the display device. Such a color calibration and adaptation device is rotatable between a calibration position and an adaptation position. In the calibration position, the device is adjacent to the display surface of the display device to measure display light emitted by the display - with little or no ambient light being measured - for calibrating the display. In the adaptation position, the device is not adjacent to the display surface, and may face outwards in the same direction as the display, to measure ambient light of the environment in which the display is operating - with little or no display light being measured - for adaptively adjusting the display. [0013] By the techniques described herein, separate devices do not have to be employed to achieve both color calibration and adaptative adjustment. For example, instead of having a color sensor integrated within the display for adaptive display adjustment to the operating environment, and having a color sensor that is part of a separate device for display calibration, the same color sensor in a single calibration and adaptation device can be employed. The device may also include other components, such as a camera, microphone, and/or speakers so that the device can be used as a webcam.

[0014] FIGs. 1 A and 1 B show side views of a color calibration and adaptation device 100 for a display device 102. The color calibration and adaptation device 100 includes a housing 104, and the display device 102 includes a housing 106. The housing 104 of the device 100 is permanently or removably mounted at an edge 105, such as a corner or a top surface, of the housing 106 of the display device 102. The housing 104 of the device 100 is rotatable between a calibration position in FIG. 1A and an adaptation position in FIG. 1 B. [0015] The color calibration and adaptation device 100 includes a color sensor 108 exposed at a surface 110, such as the front outward surface, of the housing 104 of the device 100. The color sensor 108 may be a red-green-blue- white (RGBW) color sensor to measure color in a red-green-blue (RGB) color space and white color temperature. The color sensor 108 may instead be an XYZ color sensor to measure color sensor to measure color in a deviceindependent XYZ color space and white color temperature. The color sensor 108 may be a color sensor other than a RGBW or XYZ color sensor.

[0016] The display device 102 includes a display assembly 112 to emit display light at a display surface 114, such as the front outward surface, of the housing 106 of the device 102, in correspondence with a display signal. The display signal may be internally and/or externally generated. For example, in the case in which the display device 102 is a standalone display device, the device 102 may be communicatively connected to an external device such as a computing device that transmits the display signal to the device 102. As another example, in the case in which the display device 102 is an AIO computing device, the display signal may be internally generated within the device 102.

[0017] The display assembly 112 may be implemented as an array of pixel elements, such as liquid crystal display (LCD) elements and organic light-emitting diode (OLED) elements, which are individually selectable to display images in correspondence with the display signal. The pixel elements may self-illuminate, such as in the case of OLED elements, to emit display light, or may be illuminated by a light source of the display assembly 112, such as in the case of LCD elements, to emit display light. The light source may be an array of LED elements or a fluorescent lamp like a cold cathode fluorescent lamp (CCFL), and may be side- or back-mounted relative to the pixel elements. The display assembly 112 may also include the circuit(s) that control the pixel elements to emit display light in accordance with the display signal.

[0018] The display device 102 also includes a control circuit 116 disposed within the housing 106 of the device 102, which calibrates and adaptively adjusts the display assembly 112. The control circuit 116 may be considered as including a processor and memory, which may more generally be considered as non-transitory computer-readable data storage medium. The processor and memory may be integrated within an application-specific integrated circuit (ASIC), or the processor may be a general-purpose processor, in which case the memory may be a separate semiconductor or other type of memory. The control circuit 116 can execute instructions or program code.

[0019] In the calibration position of the color calibration and adaptation device 100 per FIG. 1A, the housing 104 is rotated downwards so that the surface 110 is adjacent to the display surface 114 of the display device 102. In this position, the color sensor 108 of the device 100 measures display light emitted by the display assembly 112 of the display device 102. The surface 110 may be in contact with the display surface 114, so that the color sensor 108 measures the emitted display light and little or none of the ambient light of the environment in which the devices 100 and 102 are operating. The control circuit 116 can therefore calibrate the display assembly 112 based on the emitted display light as measured by the color sensor 108.

[0020] In the adaptation position of the color calibration and adaptation device 100 per FIG. 1 B, the housing 104 is rotated upwards so that the surface 110 is not adjacent to the display surface 114 of the display device 102. For example, the surface 110 of the device 100 may face outwards in the same direction as the display surface 114 faces outwards. In this position, the color sensor 108 of the device measures ambient light of the environment in which the devices 100 and 102 are operating. Because the surface 110 is facing outwards in the same direction as the display surface 114, the color sensor 108 may measure the ambient light and little or none of the emitted display light. The control circuit 116 can therefore adjust the display assembly 112 based on the ambient light as measured by the color sensor 108 to adapt emission of display light to the ambient light of the environment of the display device 102.

[0021] FIG. 2 shows an example non-transitory computer-readable data storage medium 200 storing program code 202 executable by a processor to perform processing. The data storage medium 200 and/or the processor may be part of the display device 102, such as in the form of the control circuit 116. Therefore, the control circuit 116 may perform the processing. The processing includes determining the position of the surface 110 of the color calibration and adaptation device 100 relative to the display surface 114 of the display device 102 (204). [0022] That is, the processing can include determining whether the color calibration and adaptation device 100 is in the calibration position of FIG. 1A or in the adaptation position of FIG. 1 B. The device 100 may be determined to be in the adaptation position at any time it is determined that the device is not in the calibration position. Determining the position of the device 100 relative to the display surface 114 can be performed automatically or manually.

[0023] For instance, the color calibration and adaptation device 100 may include an orientation sensor for automatic position determination. As one example, the orientation sensor may be a tilt sensor, such as an accelerometer, that can indicate whether and by how much the device 100 has been tilted from the adaptation position of FIG. 1 B through and to the calibration position of FIG. 1A. As another example, the orientation sensor may be a Hall effect sensor that can indicate whether the device 100 is in the calibration position or not (and thus whether the device 100 is in the calibration position or the adaptation position).

[0024] The position determination may instead be manual. A user may enter a calibration mode of the display device 102 in which the user is requested to rotate the color calibration and adaptation device 100 to the calibration position of FIG. 1A and may then indicate that the device 100 has been placed in the calibration position. A user may enable an adaptive adjustment mode of the display device 102, such that the user is requested to rotate the device 100 to the adaptation position of FIG. 1 B and may then indicate that the device 100 has been placed in the adaptation position. [0025] The processing includes, in response to determining that the surface 110 of the color calibration and adaptation device 100 is adjacent to the display surface 114 (i.e., that the device 100 is in the calibration position of FIG. 1A), calibrating the display device 102 using the color sensor 108 of the device 100 (206). The color sensor 108 is operable in the calibration position to measure display light emitted by the display assembly 112 at the display surface 114 for calibration of the assembly 112. Example calibration is described later in the detailed description.

[0026] The processing includes, in response to determining that the surface 110 of the color calibration and adaptation device 100 is not adjacent to the display surface (i.e., that the device 100 is in the adaptation position of FIG. 1 B), adaptively adjusting the display device 102 using the color sensor 108 of the device 100 (208). The color sensor 108 is operable in the adaptation position to measure ambient light of the environment of the display device 102 for adaptive adjustment of the display assembly 112 to the ambient light. Example adaptive adjustment is described later in the detailed description.

[0027] The processing of FIG. 2 can be repeated. For example, a user may first initiate color calibration of the display device 102 in which the color calibration and adaptation device 100 is in the calibration position of FIG. 1A. Once the display device 102 has been calibrated, the user may enable continuous adaptive adjustment of the display device 102 to the ambient light of the environment of the display device 102 in which the device 100 is in the adaptation position of FIG. 1 B. The user may then periodically recalibrate the display device 102 as desired, and after each calibration, return the device 100 to the adaptation position to permit continuous adaptive adjustment of the display device 102.

[0028] FIG. 3 shows a flowchart of an example method 300 for calibrating the display device 102 when the color calibration and adaptation device 100 is in the calibration position of FIG. 1A. The method 300 can implement the processing of 206 of FIG. 2, and thus can be performed by the control circuit 116 of the display device 102. The method 300 includes causing the display assembly 112 of the display device 102 to emit specified colors and brightnesses (i.e., specified colors at specified brightnesses) of display light at the display surface 114 (302).

[0029] For example, the specified colors and brightnesses can include the primary colors of the color space of the display device 102 at different levels of brightness from minimum to maximum brightness. The primary colors may be red, green, and blue in the case of the RGB color space. The specified colors can also include white, which may be a combination of all the primary colors red, green, and blue, at different levels of brightness from minimum to maximum brightness.

[0030] The method 300 includes measuring the specified colors and the specified brightnesses using the color sensor 108 of the color calibration and adaptation device 100 (304). Because the device 100 is in the calibration position of FIG. 1A, the color sensor 108 is adjacent to the display surface 114 and may measure just display light that the display assembly 112 of the display device 102 emits at the display surface 114. The emitted display light as measured differs depending on the specified color and the specified brightness that the display assembly 112 has been caused to output.

[0031] The method 300 includes adjusting the display light that the display assembly 112 of the display device 102 emits at the display surface 114 based on the previously emitted display light as measured by the color sensor 108 (306). For instance, the white point and/or the brightness of the display device 102 may be adjusted. Specifically, the subsequent emission of display light is adjusted based on a comparison between the specified colors and brightnesses of the previously emitted display light as measured and as expected.

[0032] For example, specified colors and brightnesses of the display light may be emitted based on an assumption that the display device 102 is operating a nominal white point and brightness. However, the specified colors and brightnesses of the emitted display light as measured may indicate that the display device 102 in actuality skews from this nominal white point and brightness. Therefore, the internal white point and brightness of the display device 102 can be adjusted to compensate for this skew, so that subsequently emitted display light is emitted with more accurate color and brightness reproduction and rendition.

[0033] FIG. 4 shows a flowchart of an example method 400 for adjusting the display device 102 to adapt to the ambient light of the environment of the display device 102 when the color calibration and adaptation device 100 is in the adaptation position of FIG. 1 B. The method 400 can implement the processing 208 of FIG. 2, and thus can be performed by the control circuit 116 of the display device 102. The method 400 includes measuring the color temperature and brightness of the ambient light of the environment in which the devices 100 and 102 are operating using the color sensor 108 of the device 100 (402). Because the device 100 is in the adaptation position, the color sensor 108 may be facing outwards in the same direction as the display surface 114 of the display device 102, and therefore may measure just the ambient light of the environment.

[0034] The method 400 can include adjusting the color temperature of the display device 102 to match the color temperature of the ambient light of the environment as measured by the color sensor 108 (404). For instance, if the measured color temperature of the ambient light is 3000K, then the color temperature of the display device 102 may be adjusted to also be 3000K. This can mean that the white point of the display device 102, as may have already been calibrated via the method 300 of FIG. 3, may be further adjusted so that display assembly 112 emits display light at the color temperature of the environment’s ambient light.

[0035] The method 400 can also or instead include adjusting the brightness of the display device 102 in correspondence with the brightness of the ambient light of the environment as measured by the color sensor 108 (406). For instance, as the ambient light becomes darker, the brightness at which the display assembly 112 emits display light, which may already have been calibrated via the method 300 of FIG. 3, may be decreased. Similarly, as the ambient light becomes brighter, the brightness at which display light is emitted, which may already have been calibrated via the method 300, may be increased. How much the ambient light changes in correspondence with the brightness of the environment’s ambient light may be preset or user adjustable.

[0036] FIG. 5A shows an example in which the calibration and adaptation device 100 is permanently mounted to the display device 102. That is, in the example, the device 100 is an integral part of the display device 102. The device 100 is hingeably mounted at the edge 105 of the display device 102 via a hinge 502, which may also be referred to as a hinge mount. The hinge 502 permits the housing 104 of the device 100 to rotate between the calibration position in which the color sensor 108 at the surface 110 of the housing 104 is adjacent to the display surface 114 at which the display assembly 112 is exposed within the housing 106 of the display device 102, and the adaptation position in which the sensor 108 is not adjacent to the display surface 114.

[0037] FIG. 5B shows an example in which the calibration and adaptation device 100 is removably mounted to the display device 102. That is, in the example, the device 100 is a separable part from the display device 102. The device 100 includes a hinge 552 and bracket portions 554, 556, and 558, which may constitute a hinge mount by which the housing 104 is hingably mounted at the edge of the display device 102. The hinge 552 permits the housing 104 of the device 100 to rotate between the calibration position in which the color sensor 108 at the surface 110 of the housing 104 is adjacent to the display surface 114 at which the display assembly 112 is exposed within the housing 106 of the display device 102, and the adaptation position in which the sensor 108 is not adjacent to the display surface 114.

[0038] The bracket portions 554, 556, and 558 together form an adjustable C- or U-shaped bracket that can be fitted to a display device 102 of varying thickness between the display surface 114 and a back surface 562. The bracket portion 558 is telescopingly slidable into and out of an opening 560 of the bracket portion 556. Therefore, the bracket portion 558 can be extended from or retracted into the bracket portion 556 so that the bracket portion 556 securely fits against the back surface 562 and the top surface 564 of the housing 106 of the display device 102, the bracket portion 558 securely fits against the top surface 564, and the bracket portion 554 securely fits against the display surface 114. [0039] In the example, the housing 104 of the color calibration and adaptation device 100 has a projection at area 566 to permit the surface 110 of the housing 104 - and thus the color sensor 108 - to contact and be adjacently positioned against the display surface 114 in the calibration position. The thickness of the bracket portion 554 means that the entire housing 104 of the device 100 cannot be in contact with the display surface 114 in the calibration position due to interference between a corner of the bracket portion 554 and the housing 104. The projection of the housing 104 at the area 566 therefore compensates for this interference so that the portion of the housing 104 at which the color sensor 108 is exposed can still be adjacent to the display surface 114 in the calibration position. [0040] FIG. 6 shows a front view of the example color calibration and adaptation device 100. The device 100 includes the color sensor 108 exposed at the surface 110 of the housing 104. In the example, the device 100 also includes a brightness sensor 602 exposed at the surface 110. The brightness sensor 602 may be separate from the color sensor 108 as shown, or may be integrated as part of the same sensor as the color sensor 108. That is, the color sensor 108 may also be the brightness sensor 602. The brightness sensor is operable in the calibration position of FIG. 1A to measure display brightness of emitted display light to calibrate the display device 102, and in the adaptation position of FIG. 1 B to measure ambient brightness of the environment to adaptively adjust the display device 102. The device 100 may include an orientation sensor 610 disposed within the housing 104, to detect the current position as the calibration position or the adaptation position, as has been described.

[0041] The color calibration and adaptation device 100 can also include a camera device 604, one or multiple speaker devices 606, and/or a microphone device 608 exposed at the surface 110 of the housing 104. The camera device 604 captures images in front of the display surface 114 of the display device 102, such as images of the user positioned in front of the display device 102, in the adaptation position of FIG. 1 B. The microphone device 608 records (first) audio within the environment of the display device 102, such as speech articulated by the user. The speaker devices 606 output (second) audio within the environment, such as that which may be generated by the display device 102 or by a computing or other device communicatively connected to the display device 102.

The devices 604, 606, and/or 608 can permit the device 100 to also be used as a webcam for virtual meeting purposes, for instance.

[0042] A color calibration and adaptation device 100 has been described that includes a color sensor 108 that can be used both for calibration of a display device 102 and adjustment of the display device 102 for adaptation to the ambient light of the environment in the display device 102 is operating. The rotation of the device 100 between a calibration position in which the color sensor 108 is adjacent to the display surface 114 of the display device 102 and an adaptation position in which the color sensor 108 is not adjacent to the display surface 114 permits usage of the color sensor 108 for both calibration and adaptative adjustment. As a result, separate sensors are not required to both calibrate and adaptively adjust the display device 102.