# US 9,872,002 B2 · Method and device for controlling projection of wearable apparatus, and wearable apparatus

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- Number: US 9,872,002 B2
- Document ID: US9872002B2
- Status: Granted
- Kind: B2
- Application number: 14/437,112
- Filed: 2014-08-26
- Published: 2016-10-13
- Granted: 2018-01-16
- Earliest claimed: 2014-04-28
- Assignees: Boe Technology Group Co., Ltd.
- Applicants: Boe Technology Group Co., Ltd.
- Inventors: Xingxing Zhao; Yanshun Chen; Qiushi Xu; Yaohui Li
- Web page: https://patentgrep.com/patent/US9872002B2

## CPC

- H04N 9/3185: {Geometric adjustment, e.g. keystone or convergence (optical or mechanical adjustment of convergence H04N9/317; using scanning means H04N3/22; optical or mechanical adjustments of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/14)}
- G01B 11/00: Measuring arrangements characterised by the use of optical techniques
- H04N 9/3155: {for controlling the light source (light source control per se H05B35/00 – H05B47/00; control of an illumination source for displays in general G09G3/3406)}
- H04N 9/317: {Convergence or focusing systems (electronic adjustment of convergence H04N9/3185; convergence or focusing arrangements for cathode ray tubes H04N9/28; means for automatic focusing of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/53)}
- H04N 9/3173: {wherein the projection device is specially adapted for enhanced portability}
- H04N 9/3176: {wherein the projection device is incorporated in a camera (details of cameras adapted for combination with a projector not peculiar to the presence of an electronic spatial light modulator G03B17/54)}
- H04N 9/3188: {Scale or resolution adjustment (scaling in general G06T3/40; resolution modifying circuits for displays in general G09G5/391)}
- H04N 9/3194: {including sensor feedback}
- H04N 13/275: from three-dimensional [3D] object models, e.g. computer-generated stereoscopic image signals
- G01B 11/24: for measuring contours or curvatures
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION
- G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS

## Abstract

A method and a device for controlling projection of a wearable apparatus, and a wearable apparatus are provided. With the projection method, a 3D profile of the object as projection screen is acquired by a 3D acquisition device disposed on the wearable apparatus; coordinates of vertices of the projection area on the object as projection screen are determined according to the acquired 3D profile of the object as projection screen; a projection plane is determined according to the determined coordinates of vertices; and the projection is controlled according to the angle between the projection plane and the center line of the projection view angle of the projection component, the distance between the geometrical center of the projection plane and the projection component and the 3D profile of the object as projection screen such that the projection picture projected by the projection component is clearly and steadily projection displayed in the projection area on the object as projection screen.

## Claims

### Claim 1

A method for controlling projection of a wearable apparatus that is provided with a projection component, comprising:
acquiring a 3D profile of an object as a projection screen by a 3D acquisition device disposed on the wearable apparatus;
determining coordinates of vertices of a projection area on the object as the projection screen according to the acquired 3D profile of the object as the projection screen;
determining a projection plane according to the determined coordinates of the vertices; and
controlling the projection according to an angle between the projection plane and a center line of an projection view angle of the projection component, a distance between a geometrical center of the projection plane and the projection component, and the 3D profile of the object as the projection screen,
wherein a display luminance of a projection picture projected in the projection area on the object as the projection screen is corrected according to the 3D profile of the object as the projection screen at least by:
determining an extent of deformation of the projection screen through a calculation operation including an integral operation that is related to the 3D profile of the object as the projection screen; and
adjusting the display luminance of the projection picture according to the extent of deformation of the projection screen.

### Claim 2 (depends on 1)

The method of claim 1, wherein a plane with a minimum sum of variances of distances from the determined coordinates of the vertices is determined as the projection plane.

### Claim 3 (depends on 2)

The method of claim 2, wherein,
a shape of the projection picture projected by the projection component is adjusted according to the angle between the projection plane and the center line of the projection view angle of the projection component such that the projection picture projected onto the object as the projection screen adapts to a shape of the projection area on the object as the projection screen; and
a size of the projection picture projected by the projection component is adjusted according to the distance between the geometrical center of the projection plane and the projection component such that the projection picture projected onto the object as the projection screen adapts to a size of the projection area on the object as the projection screen.

### Claim 4 (depends on 3)

The method of claim 3, wherein,
a correction angle for keystone correction of the projection picture projected by the projection component is determined according to the angle between the projection plane and the center line of the projection view angle of the projection component; and
the projection picture projected by the projection component is keystone-corrected according to the correction angle.

### Claim 5 (depends on 3)

The method of claim 3, wherein,
a compression ratio for compressing the projection picture projected by the projection component is determined according to a formula
ϕ
=
L_
⁢
1
L_
⁢
0
*
(
d
1
/
d
0
)
;
a size of the projection picture projected by the projection component is adjusted to a size that is obtained after the projection picture projected by the projection component is compressed according to the compression ratio;
where φ is the compression ratio for compressing the projection picture projected by the projection component, L_1 is the size of the object as the projection screen, L_0 is a preset size of the projection screen, d1 is a distance between the geometrical center of the projection plane and the projection component, and d0 is a distance between the corresponding geometrical center of the projection plane and the projection component when the size of projection area equals the size of the projection screen.

### Claim 6 (depends on 3)

The method of claim 3, wherein,
the display luminance of the projection picture in the projection area on the object as the projection screen is determined according to a formula
L_out(x,y)=L_in(x,y)*∫(x,y,z);
the display luminance of the projection picture projected in the projection area on the object as the projection screen is corrected according to the determinate display luminance,
where L_out(x, y) is the display luminance of the projection picture at the location corresponding to a coordinate point (x, y) in the projection area on the object as the projection screen, L_in(x, y) is the display luminance of the display picture projected at the coordinate point (x, y), and ∫(x, y, z) denotes the integral operation and represents an integral of the three dimensional coordinate point in the 3D profile of the object as the projection screen that corresponds to the coordinate point (x, y) in the projection area on the object as the projection screen.

### Claim 7 (depends on 1)

The method of claim 1, wherein,
a shape of the projection picture projected by the projection component is adjusted according to the angle between the projection plane and the center line of the projection view angle of the projection component such that the projection picture projected onto the object as the projection screen adapts to a shape of the projection area on the object as the projection screen; and
a size of the projection picture projected by the projection component is adjusted according to the distance between the geometrical center of the projection plane and the projection component such that the projection picture projected onto the object as the projection screen adapts to a size of the projection area on the object as the projection screen.

### Claim 8 (depends on 7)

The method of claim 7, wherein,
a correction angle for keystone correction of the projection picture projected by the projection component is determined according to the angle between the projection plane and the center line of the projection view angle of the projection component; and
the projection picture projected by the projection component is keystone-corrected according to the correction angle.

### Claim 9 (depends on 7)

The method of claim 7, wherein,
a compression ratio for compressing the projection picture projected by the projection component is determined according to a formula
ϕ
=
L_
⁢
1
L_
⁢
0
*
(
d
1
/
d
0
)
;
a size of the projection picture projected by the projection component is adjusted to a size that is obtained after the projection picture projected by the projection component is compressed according to the compression ratio;
where φ is the compression ratio for compressing the projection picture projected by the projection component, L_1 is the size of the object as the projection screen, L_0 is a preset size of the projection screen, d1 is a distance between the geometrical center of the projection plane and the projection component, and d0 is a distance between the corresponding geometrical center of the projection plane and the projection component when the size of projection area equals the size of the projection screen.

### Claim 10 (depends on 1)

The method of claim 1, wherein,
the display luminance of the projection picture in the projection area on the object as the projection screen is determined according to a formula
L_out(x,y)=L_in(x,y)*∫(x,y,z);
the display luminance of the projection picture projected in the projection area on the object as the projection screen is corrected according to the determinate display luminance,
where L_out(x, y) is the display luminance of the projection picture at the location corresponding to a coordinate point (x, y) in the projection area on the object as the projection screen, L_in(x, y) is the display luminance of the display picture projected at the coordinate point (x, y), and ∫(x, y, z) denotes the integral operation and represents an integral of the three dimensional coordinate point in the 3D profile of the object as the projection screen that corresponds to the coordinate point (x, y) in the projection area on the object as the projection screen.

### Claim 11 (depends on 1)

The method of claim 1, wherein the wearable apparatus is an intelligent finger ring and the object as the projection screen is a palm.

### Claim 12

A device for controlling projection of a wearable apparatus that is provided with a projection component, comprising:
a 3D acquisition device disposed on the wearable apparatus, configured to acquire a 3D profile of an object as a projection screen;
a processor; and
a memory that stores instructions, when executed by the processor, configured to perform operations including:
determining coordinates of vertices of a projection area on the object as the projection screen according to the 3D profile of the object as the projection screen and determining a projection plane according to the determined coordinates of the vertices; and
controlling the projection according to an angle between a center line of an projection view angle of the projection component and the projection plane, a distance between a geometrical center of the projection plane and the projection component, and the 3D profile of the object as the projection screen,
wherein the instructions when executed by the processor are further configured to correct a display luminance of a projection picture projected in the projection area on the object as the projection screen according to the 3D profile of the object as the projection screen at least by:
determining an extent of deformation of the projection screen through a calculation operation including an integral operation that is related to the 3D profile of the object as the projection screen; and
adjusting the display luminance of the projection picture according to the extent of deformation of the projection screen.

### Claim 13 (depends on 12)

The device of claim 12, wherein the instructions when executed by the processor are further configured to determine a plane with a minimum sum of variances of distances from the determined coordinates of the vertices as the projection plane.

### Claim 14 (depends on 13)

The device of claim 13, wherein the instructions when executed by the processor are further configured to:
adjust a shape of the projection picture projected by the projection component according to the angle between the projection plane and the center line of the projection view angle of the projection component such that the projection picture projected onto the object as the projection screen adapts to a shape of the projection area on the object as the projection screen; and
adjust a size of the projection picture projected by the projection component according to the distance between the geometrical center of the projection plane and the projection component such that the projection picture projected onto the object as the projection screen adapts to a size of the projection area on the object as the projection screen.

### Claim 15 (depends on 12)

The device of claim 12, wherein the instructions when executed by the processor are further configured to:
adjust a shape of the projection picture projected by the projection component according to the angle between the projection plane and the center line of the projection view angle of the projection component such that the projection picture projected onto the object as the projection screen adapts to a shape of the projection area on the object as the projection screen; and
adjust a size of the projection picture projected by the projection component according to the distance between the geometrical center of the projection plane and the projection component such that the projection picture projected onto the object as the projection screen adapts to a size of the projection area on the object as the projection screen.

### Claim 16 (depends on 15)

The device of claim 15, wherein the instructions when executed by the processor are further configured to:
determine a correction angle for keystone correction of the projection picture projected by the projection component according to the angle between the projection plane and the center line of the projection view angle of the projection component; and
keystone-correct the projection picture projected by the projection component according to the correction angle.

### Claim 17 (depends on 15)

The device of claim 15, wherein the instructions when executed by the processor are further configured to:
determine a compression ratio for compressing the projection picture projected by the projection component according to a formula
ϕ
=
L_
⁢
1
L_
⁢
0
*
(
d
1
/
d
0
)
;
adjust a size of the projection picture projected by the projection component to a size after compressing the projection picture projected by the projection component according to the compression ratio;
where φ is the compression ratio for compressing the projection picture projected by the projection component, L_1 is the size of the object as the projection screen, L_0 is a preset size of the projection screen, d1 is a distance between the geometrical center of the projection plane and the projection component, and d0 is a distance between the corresponding geometrical center of the projection plane and the projection component when the size of projection area equals the size of the projection screen.

### Claim 18 (depends on 15)

The device of claim 15, wherein the instructions when executed by the processor are further configured to:
determine the display luminance of the projection picture in the projection area on the object as the projection screen according to a formula
L_out(x,y)=L_in(x,y)*∫(x,y,z); and
correct the display luminance of the projection picture projected in the projection area on the object as the projection screen according to the determinate display luminance,
where L_out(x, y) is the display luminance of the projection picture at the location corresponding to a coordinate point (x, y) in the projection area on the object as the projection screen, L_in(x, y) is the display luminance of the display picture projected at the coordinate point (x, y), and ∫(x, y, z) denotes the integral operation and represents an integral of the three dimensional coordinate point in the 3D profile of the object as the projection screen that corresponds to the coordinate point (x, y) in the projection area on the object as the projection screen.

### Claim 19 (depends on 12)

The device of claim 12, wherein the wearable apparatus is an intelligent finger ring and the object as the projection screen is a palm.

### Claim 20 (depends on 12)

A wearable apparatus comprising a projection component and a device for controlling projection of a wearable apparatus of claim 12.