Display screen viewing angle test method

Abstract

The present application relates to a display screen visual angle testing method, which places the display screen under a certain rotation angle for detection, the light collecting axis of the detection instrument and the central normal of the display screen are perpendicular to the rotation axis of the display screen, the position of the detection instrument in the direction of the rotation axis of the display screen is the same as the position of the center of the display screen in the direction of the rotation axis of the display screen, the position coordinate of the detection instrument or the position coordinate change value is calculated according to the display rotation angle or the display rotation angle change value, and the detection instrument is controlled to move to the corresponding position according to the position coordinate or the position coordinate change value, that is, the detection instrument is aligned with the center of the display screen and keeps a constant distance with the center of the display screen, and the detection brightness can be converted into equivalent brightness according to the introduced equivalent brightness, so that the related analysis and evaluation are more accurate. The present application is convenient and practical, and is convenient for automatic control of detection.

Description

Technical Field

[0001] This invention relates to a method for testing the viewing angle of a display screen, which can be used to detect the brightness, especially the spectral radiance, of various display screens. Background Technology

[0002] Due to work and life demands, people's dependence on electronic products such as mobile phones and computers has been increasing year by year. Prolonged use of display devices such as mobile phones, tablets, and computers has become a very common phenomenon in today's society. The time people spend looking at screens is also constantly rising. While paying attention to display quality, people are also paying more and more attention to the safety and health effects of light radiation from display products, especially the potential harm of blue light radiation to the retina from prolonged screen viewing. Therefore, it is necessary to test the spectral radiation brightness of screens, such as blue light radiation, to evaluate the characteristics of the screen, determine the impact of prolonged observation on the human eye, and provide a basis for the health and quality control of screens.

[0003] Chinese patent document CN217360484U discloses a device for detecting the brightness uniformity of a display screen, comprising: a clamp, a rotating frame, a sliding component, and a testing component. The clamp is detachably connected to the rotating frame, and the testing component is disposed on the sliding component and positioned opposite the rotating frame. The clamp holds the display screen to be tested, and the clamp is mounted on the rotating frame, causing the rotating frame to rotate the display screen to provide the display status of the display screen under test at different viewing angles. The testing component is disposed on the sliding component and positioned opposite the rotating frame to detect the display status of the display screen mounted on the rotating frame at different distances. This detection device allows the display screen to rotate horizontally for testing from different angles, and can also adjust the spatial position of the testing component, thereby adjusting the relative position and relative distance between the testing component and the display screen, providing convenience for display screen brightness detection. However, for display screen (or monitor) viewing angle detection, there is still a lack of necessary detection rules, equipment control during the detection process, and methods for processing detection data. Therefore, it is necessary to conduct further technical development for display screen viewing angle detection based on existing technology. Summary of the Invention

[0004] The purpose of this invention is to provide a convenient and practical method for testing the viewing angle of a display screen.

[0005] The technical solution of this invention is: a display screen viewing angle testing method, in which the display screen is placed at a certain angle (in a state of being at a certain angle) for testing. The light-collecting axis of the testing instrument (e.g., the lens axis, or other straight lines that can characterize the orientation of the lens of the testing / measuring instrument) and the normal line of the display screen center (the normal line of the display surface passing through the center of the display screen, or other straight lines that can characterize the orientation of the display screen and pass through the center of the display screen) are perpendicular to the rotation axis of the display screen. The position of the testing instrument in the direction of the rotation axis of the display screen is the same as the position of the display screen center (the center of the display surface of the display screen, or the display screen center defined / determined in other ways) in the direction of the rotation axis of the display screen (e.g., when the rotation axis of the display screen is vertical, the testing instrument is set horizontally and its lens height / light-collecting port height is the same as the height of the display screen center).

[0006] Calculate the position coordinates of the testing instrument when the display screen rotates at an angle θ (the position coordinates of the testing instrument during testing) using the following formula:

[0007] x L = -hsin(θ) - kcos(θ),

[0008] y L =hcos(θ)-ksin(θ)+n,

[0009] or,

[0010] The change in the position coordinates of the detection instrument when the display screen angle changes from θ to θ+Δθ is calculated using the following formula (the change in coordinates of the detection instrument from its position when the display screen angle is θ to its position when the display screen angle is θ+Δθ).

[0011] Δx L =-hsin(θ+1)-kcos(θ+Δθ)+hsin(θ)+kcos(θ),

[0012] Δy L =hcos(θ+1)-ksin(θ+Δθ)-hcos(θ)+ksin(θ),

[0013] Based on the calculated position coordinates of the testing instrument, or based on the calculated changes in the position coordinates of the testing instrument, the testing instrument is controlled to move to the corresponding coordinate position in the corresponding coordinate direction, so as to perform testing at the corresponding angle.

[0014] in,

[0015] x L and y L These are the x-axis and y-axis coordinates of the instrument's position, respectively, depending on the display screen's rotation angle θ.

[0016] ΔxL and Δy L These represent the changes in the x-axis coordinate (coordinate value difference) and y-axis coordinate (coordinate value difference) of the instrument's position when the display screen rotation angle changes from θ to θ+Δθ.

[0017] The display screen rotation angle is the forward rotation angle of the display screen relative to a reference state; that is, the forward rotation angle of the display screen's center normal relative to the y-axis.

[0018] -k and h are the x-axis coordinates (coordinate values) and y-axis coordinates (coordinate values) of the center of the display screen in the baseline state, respectively.

[0019] n represents the distance between the testing instrument and the display screen under the baseline condition.

[0020] The so-called forward rotation angle is equal to the angle rotated around the origin of the coordinate system (or the z-axis) until it is parallel to / overlaps with the normal to the center of the display screen. Forward rotation is defined as rotation in the direction where the x-axis rotates 90° around the origin of the coordinate system (or the z-axis) to overlap with the y-axis. The opposite direction of forward rotation is called reverse rotation.

[0021] The reference state is defined as the state where the normal of the display screen is parallel to or overlaps with the y-axis and the light-collecting axis of the detection instrument is aligned with the center of the display screen. The reference state can be used as or regarded as the starting state.

[0022] Under baseline conditions, the x-axis and y-axis coordinates of the testing instrument are -k and h+n, respectively.

[0023] The coordinate system used is a (planar) rectangular coordinate system, with the origin located on the rotation axis of the display screen, the y-axis pointing to the testing instrument in the standard state, and the x-axis perpendicular to the y-axis and the rotation axis of the display screen.

[0024] A coordinate system can be established based on the convenience of coordinate-related calculations and motion control. For example, depending on the detection device used, the x-axis, y-axis, and z-axis of the coordinate system can be set in the three linear motion directions of the detection instrument, or the x-axis and y-axis of the coordinate system (for example, when using a planar coordinate system) can be set in the two linear motion directions of the detection instrument, with the rotation axis of the display screen on the z-axis.

[0025] Depending on the actual needs, some detection devices have multiple rotational degrees of freedom, enabling the display screen to rotate around multiple different rotation axes. Since the position changes and movement control of the detection instrument at different rotation angles are planar, a Cartesian coordinate system can be used based on the involved rotation axes. When the display screen needs to rotate around different axes, the directions of each axis in the coordinate system can be redefined based on the changes in the rotation axes, or the axes can be substituted for each other.

[0026] Preferably, the rotation angle of the display screen is increased (forward rotation) and / or decreased (reverse rotation) with equal steps (equal angular distance) (forward and / or reverse rotation of the display screen), and the display screen is detected sequentially at each rotation angle to form an equal angular distance (equal rotation angle) detection dataset of the entire field of view or a selected field of view.

[0027] For example, the stride (angular distance) detected by equal angular distance (equal rotation angle) can be 1°.

[0028] Preferably, starting from the reference state, equal angular distance (equal rotation angle) detection is performed on the forward side (the side entered by forward rotation) and the reverse side (the side entered by reverse rotation) of the field of view. In the reverse side field of view, the negative value of the reverse rotation angle can be regarded as the display screen rotation angle in the corresponding state, and used to calculate the position coordinates or position coordinate change value of the detection instrument.

[0029] Furthermore, a two-dimensional moving mechanism can be set up, consisting of a longitudinal (y-axis direction, or y-direction) sliding joint and a transverse (x-axis direction, or x-direction) sliding joint. The detection instrument is fixedly mounted on the output component (the two-dimensional moving component on the output side / passive side, used to mount the object to be moved) of the two-dimensional moving mechanism, or the detection instrument is connected to the output component of the two-dimensional moving mechanism through a vertical (z-axis direction, or z-direction) sliding joint. Based on the calculated y-axis coordinates or y-axis coordinate changes of the detection instrument, the longitudinal position of the detection instrument is adjusted through the longitudinal sliding joint in the two-dimensional moving mechanism, and based on the calculated x-axis coordinates or x-axis coordinate changes of the detection instrument, the transverse position of the detection instrument is adjusted through the transverse sliding joint in the two-dimensional moving mechanism.

[0030] When a vertical moving part is provided, the vertical position of the testing instrument can be adjusted by means of the vertical moving part based on the vertical position (z-axis coordinate) of the center of the display screen.

[0031] A rotating mechanism (e.g., a turntable) can be set up to vertically mount the display screen on the output component of the rotating mechanism (the rotating component on the output / passive side, used to mount the object to be rotated). According to the set target rotation angle, the rotating mechanism drives the display screen to rotate to the corresponding rotation angle.

[0032] The detection instrument can be a luminance meter.

[0033] Furthermore, the equivalent brightness of the detected brightness (at any screen rotation angle θ) is calculated according to the following formula:

[0034] L Eθ =L θ ×K S ,

[0035]

[0036] in,

[0037] L θ To measure the brightness (actual brightness) at a rotation angle θ,

[0038] L Eθ For L θ The equivalent brightness,

[0039] K s This is the brightness correction factor (equivalent conversion factor).

[0040] 2γ is the test field of view of the luminance meter, or in other words, γ is 1 / 2 of the test field of view of the luminance meter.

[0041] Preferably, the evaluation or comparative analysis of radiation-related characteristics of the display screen under different rotation angles / viewing angles is based on the equivalent brightness.

[0042] Preferably, the detection instrument is a spectroradiometer or a blue light radiometer.

[0043] Preferably, the detected brightness (display screen radiant brightness) is the blue light radiant brightness.

[0044] The beneficial effects of this invention are: it can calculate the position coordinates of the detection instrument based on the rotation angle of the display screen, and move the detection instrument to the correct position according to the calculated position coordinates, so that the detection instrument will be aligned with the center of the display screen and maintain a constant distance from the center of the display screen, thus facilitating its use; since the y-axis and x-axis movements are decoupled, the movement of the detection instrument in each direction can be independently adjusted and controlled according to the coordinates of each axis, simplifying the control method and movement process, and facilitating automatic control using automatic control technology; since equivalent brightness is introduced, the influence of the projected area on the detection brightness at different rotation angles can be eliminated, and the use of equivalent brightness is more accurate when evaluating the radiation characteristics of the display screen itself. Attached Figure Description

[0045] Figure 1 It refers to the positional relationship between the display and the testing instrument in the coordinate system under the reference state;

[0046] Figure 2 It refers to the positional relationship between the display and the detection instrument in the coordinate system when the display is rotated at an angle θ.

[0047] Figure 3 This is a schematic diagram illustrating the principle of equivalent brightness. Detailed Implementation

[0048] I. Ensure the luminance meter is aligned with the center of the monitor and adjust the distance accordingly.

[0049] Taking horizontal rotation as an example, calculate the coordinate changes of the display center during the rotation process to ensure that the luminance meter is aligned with the display center and maintains a constant distance.

[0050] See Figure 1 In the reference state, A is the intersection of the display and the rotation axis y-axis, P is the horizontal center point of the display, h is the distance from the display surface to the rotation axis x-axis (including the display thickness), and n is the distance from the luminance meter to the display.

[0051] 1) The monitor is mounted and fixed on the bracket. With the center of the device's rotation axis as the origin O(0,0), the coordinates of the intersection of the monitor and the y-axis are A(0,h), the coordinates of the center point of the monitor are P(-k,h), and the coordinates of the luminance meter are L(-k,h+n).

[0052] 2) After the monitor rotates by a certain angle θ, the coordinates of point A are (x...). A ,y A The calculation formula is as follows:

[0053] x A =-hsin(θ) (1)

[0054] y A =hcos(θ) (2)

[0055] The center coordinates of the monitor are P(x) P y P The calculation formula is as follows:

[0056] x P = -hsin(θ) - kcos(θ) (3)

[0057] y P =hcos(θ)-ksin(θ) (4)

[0058] The luminance meter coordinates are L(x) L y L The calculation is as follows:

[0059] x L = -hsin(θ) - kcos(θ) (5)

[0060] y L =hcos(θ)-ksin(θ)+n (6)

[0061] 3) During the test, the monitor rotation angle increases by Δθ (e.g., 1°). Then, the coordinates (x, y, y) of the monitor center point P' are... P ',y P The calculation is as follows:

[0062] x P'=-hsin(θ+Δθ)-kcos(θ+Δθ) (7)

[0063] y P '=hcos(θ+Δθ)-ksin(θ+Δθ) (8)

[0064] Luminometer coordinates L'(x) L y L The calculation is as follows:

[0065] x L '=-hsin(θ+Δθ)-kcos(θ+Δθ) (9)

[0066] y L '=hcos(θ+Δθ)-ksin(θ+Δθ)+n (10)

[0067] Calculate the changes in x and y axis coordinates using the following formulas:

[0068] Δx=-ksin(θ+Δθ)-kcos(θ+Δθ)+hsin(θ)+kcos(θ) (11)

[0069] Δy=hcos(θ+Δθ)-ksin(θ+Δθ)-hcos(θ)+ksin(θ) (12)

[0070] Based on the above coordinate values, the brightness meter can be moved by the corresponding distances Δx and Δy by the control device / software of the detection device, thus ensuring that the brightness meter is aligned with the center of the display and the distance remains constant.

[0071] II. Method for Calculating Equivalent Brightness After Monitor Rotation

[0072] The luminance meter measures the field of view as a solid angle of 2γ. Since the actual area of ​​the display area measured by the luminance meter changes after the monitor is rotated, the luminance measurement data should be corrected accordingly.

[0073] The equation of the field-of-view cone surface of the luminance meter is:

[0074] m 2 (x 2 +z 2 ) = R 2 (my) 2 , where x 2 +z 2 ≤R 2 ,0≤y≤m (13)

[0075] The equation of the plane on which the display screen is located is:

[0076] Ax + By + Cz = D (14)

[0077] After the display is rotated by a certain angle θ, the cross-sectional area is calculated using an inclined plane parallel to the z-axis (B≠0, C=0). The plane equation simplifies to:

[0078]

[0079] Rewritten as:

[0080] y = kx + b (15)

[0081] Combining the equation of the conical surface with the equation of the projected curve of the cross-section plane, we obtain the equation of the projected curve of the cross-section plane as follows:

[0082] (m 2 -k 2 R 2 )x 2 +2k(mb)R 2 x+m 2 z 2 =(mb) 2 R 2 (16)

[0083] The projection curve is an ellipse.

[0084] The straight line y = kx + b (assuming k > 0) passes through the bottom endpoint Q of the cone (located on the x-axis). The coordinates of point P are (x...). Q y Q Given (R, 0), we can find b = kR. Substituting this into the equation of the projection curve, we get:

[0085] (m 2 -k 2 R 2 )x 2 +2k(m-kR)R 2 x+m 2 z 2 =(m-kR) 2 R 2 (17)

[0086] but:

[0087] The semi-major axis of the ellipse:

[0088] The semi-minor axis of the ellipse:

[0089] Ellipse area:

[0090]

[0091]

[0092] R = mtanγ,

[0093]

[0094] Area of ​​the detection area before the monitor rotates:

[0095] S=πr 2 =πm 2 (1-tanγtanθ) 2 (tanγ) 2 (20)

[0096] The viewing angle brightness correction factor is:

[0097]

[0098] During the viewing angle test, the brightness L was measured after the monitor was rotated. θ Equivalent brightness L Eθ for:

[0099] L Eθ =L θ ×K S (twenty two)

[0100] The rotation of the display screen and the movement of the testing instrument in all directions can be achieved using any suitable existing technology.

[0101] Unless otherwise specified, the preferred and optional technical means disclosed in this invention can be arbitrarily combined to form several different specific embodiments when one preferred or optional technical means is a further limitation of another technical means.

Claims

1. A method for testing the viewing angle of a display screen, characterized in that... The display screen is placed at a certain angle for testing. The light-collecting axis of the testing instrument and the normal to the center of the display screen are perpendicular to the rotation axis of the display screen. The position of the testing instrument along the rotation axis of the display screen is the same as the position of the center of the display screen along the rotation axis of the display screen. The rotation angle of the display screen is calculated according to the following formula: Position coordinates of the time detection instrument: ， ， or The rotation angle of the display screen is calculated according to the following formula. Become Changes in the position coordinates of the instrument during the detection process: ， ， Based on the calculated position coordinates of the testing instrument, or based on the calculated changes in the position coordinates of the testing instrument, the testing instrument is controlled to move to the corresponding coordinate position in the corresponding coordinate direction, so as to perform testing at the corresponding angle. in, and These are the positions of the detection instruments. axis coordinates and Axis coordinates and The screen corners are respectively Become In this case, the position of the detection instrument Changes in axis coordinates and Changes in axis coordinates The coordinate system used is a rectangular coordinate system, with the origin located on the rotation axis of the display screen. The axis points to the testing instrument under standard conditions. Axis perpendicular to The axis is perpendicular to the rotation axis of the display screen, and the rotation axis of the display screen is in... On the axis, The display screen rotation angle is the forward rotation angle of the display screen relative to its reference position. and The center of the display screen in the baseline state axis coordinates and Axis coordinates The distance between the measuring instrument and the display screen is measured under reference conditions. The reference state is the normal of the display screen and The reference state is used as or considered as the starting state when the axes are parallel or overlapping and the light-collecting axis of the detection instrument is aligned with the center of the display screen. The detection instrument is a luminance meter, and the equivalent luminance of the detected luminance is calculated according to the following formula: ， ， in, To at the corner The measured brightness is below. for The equivalent brightness, This is the brightness correction factor. This is the test field of view of the luminance meter.

2. The display screen viewing angle testing method as described in claim 1, characterized in that... By increasing or decreasing the rotation angle of the display screen with equal steps, the display screen is detected sequentially at each rotation angle, forming an equal-angle detection dataset for the selected field of view.

3. The display screen viewing angle testing method as described in claim 2, characterized in that... The step size for equiangular distance detection is 1°.

4. The display screen viewing angle testing method as described in claim 2, characterized in that... Starting from the baseline state, equal-angle detection is performed on the forward side field of view.

5. The display screen viewing angle testing method as described in claim 1, characterized in that... A two-dimensional moving mechanism consisting of longitudinal and lateral sliding joints is set up. The detection instrument is fixedly mounted on the output component of the two-dimensional moving mechanism, or the detection instrument is connected to the output component of the two-dimensional moving mechanism through a vertical sliding joint. Based on the calculated value of the detection instrument... Axis coordinates or The change in axis coordinates is used to adjust the longitudinal position of the detection instrument through the longitudinal sliding pair in the two-dimensional moving mechanism, based on the calculated value of the detection instrument. Axis coordinates or The change in axis coordinates is adjusted by the lateral sliding pair in the two-dimensional moving mechanism to change the lateral position of the detection instrument.

6. The display screen viewing angle testing method as described in claim 1, characterized in that... A rotating mechanism is set up, and the display screen is vertically mounted on the output of the rotating mechanism. According to the set target rotation angle, the rotating mechanism drives the display screen to rotate to the corresponding rotation angle.

7. The display screen viewing angle testing method as described in claim 1, characterized in that... Evaluation or comparative analysis of radiation-related characteristics of display screens at different rotation angles or viewing angles based on equivalent brightness.

8. The display screen viewing angle testing method as described in claim 7, characterized in that... The detection instrument is a spectroradiometer or a blue light radiometer, and the detected brightness is blue light radiance.

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