US-20260127988-A1 - Autostereoscopic Display Apparatus

US20260127988A1US 20260127988 A1US20260127988 A1US 20260127988A1US-20260127988-A1

Abstract

A display apparatus for implementing autostereoscopic display is disclosed. The apparatus includes a display pixel array configured to generate images, and an optical element array disposed above the pixel array, the optical elements being configured to direct different images to the viewer's left and right eyes to enable autostereoscopic perception. A memory stores computer-executable instructions, and a processor executes the instructions to dynamically adjust the brightness of individual pixels. An optimized brightness is derived from a continuously differentiable, monotonically increasing S-shaped function.

Inventors

Cheng-Chung Hu
Han-Hsun Kuo

Assignees

JOYVISION TECHNOLOGY.,CO LTD

Dates

Publication Date: 20260507
Application Date: 20250618
Priority Date: 20241106

Claims (8)

1 . A display apparatus, comprising: a display pixel array configured to generate images for viewing by a viewer; an optical element array disposed above the display pixel array, configured to direct different images to a viewer's left and right eyes to enable autostereoscopic perception; a memory configured to store computer-executable instructions; and a processor configured to execute the instructions, the processor further configured to: obtain, for any given display pixel, a distance d between the pixel and a nearest end of a boundary separating adjacent images; calculate a distance ratio D defined as D=d/Lp, wherein Lp is a pitch of the optical elements; and determine an optimized brightness value B for the given display pixel based on the distance ratio D, wherein the optimized brightness value B is computed according to an S-shaped function that is continuously differentiable, approaches 0 as the distance ratio D approaches 0, approaches 1 as the distance ratio D approaches 1, and has an inflection point at D=0.5.
2 . The display apparatus of claim 1 , wherein the S-shaped function used to compute the optimized brightness value B is a hyperbolic tangent function defined as: B=(1+tanh(C×(D− 0 . 5 )))/2, wherein C is a positive control coefficient that governs the slope of the brightness curve.
3 . The display apparatus of claim 1 , wherein the S-shaped function used to compute the optimized brightness value B is an error function, defined as: B=(1+erf(α×(D− 0 . 5 )))/2, wherein α is a positive control coefficient that adjusts the steepness of the brightness transition near image boundaries.
4 . The display apparatus of claim 1 , wherein the S-shaped function used to compute the optimized brightness value B is an arctangent function, defined as: B=(arctan(π×(D−0.5))/π)+0.5, wherein the function is continuously differentiable and shaped to produce a smooth S-curve with said inflection point.
5 . The display apparatus of claim 1 , wherein the S-shaped function used to compute the optimized brightness value B is a Gudermannian function, defined as: B=2/π*arctan(tanh(C(D−0.5)/2))+1/2, wherein C is a positive control coefficient that governs the steepness of the brightness transition.
6 . The display apparatus of claim 1 , wherein the S-shaped function used to compute the optimized brightness value B is a generalized logistic function, defined as: B=(1+e{circumflex over ( )}{−C(D−0.5)}){circumflex over ( )}{−α}, wherein C and α are positive constants that control the curve's slope and sharpness of transition near the inflection point.
7 . The display apparatus of claim 1 , wherein the S-shaped function used to determine the optimized brightness value B is defined as: B=x/sqrt(1+x{circumflex over ( )}2), wherein x=C(D−0.5), and C is a positive control coefficient, such that higher values of C produce steeper brightness transitions near D=0.5.
8 . The display apparatus of claim 1 , wherein the S-shaped function used to determine the brightness adjustment is stored in the memory in the form of a lookup table (LUT), and wherein the processor is configured to access the LUT, based on the calculated distance ratio D, to retrieve a corresponding brightness value.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of U.S. patent application Ser. No. 19/068,197, filed on Mar. 3, 2025, which is incorporated herein by reference in its entirety. The U.S. application claims priority under 35 U.S. C. § 119(a) to Taiwanese Patent Application No. 113142612, filed on Nov. 6, 2024, in Taiwan, Republic of China, which is also incorporated herein by reference. PRIOR ART When producing glasses-free 3D visuals with lenticular lenses, the aim is to distinctly channel light into separate colors, delivering unique images to each eye. However, crosstalk (where images intended for one eye bleed into the other) can occur at the boundaries, causing visual disturbances like ghosting. To address this, adjusting screen pixel brightness by deactivating pixels near the edges of the lenticular lens pitch can help reduce crosstalk, resulting in a clearer 3D image. The technique of deactivating pixels near lenticular lens pitches is well established in the art and is described in Patent CN110662012A. However, excessive pixel deactivation may lead to a reduction in overall display brightness, and viewers may perceive black grid patterns, resembling a screen door effect, during 3D viewing. BACKGROUND OF THE INVENTION The present invention optimizes brightness dynamically, ensuring clearer, high-quality autostereoscopic displays while reducing crosstalk artifacts. SUMMARY OF THE INVENTION It is an object of the present invention to provide a display apparatus for implementing autostereoscopic display. The apparatus comprises a display pixel array configured to generate images for viewing by a user, and an optical element array disposed above the display pixel array. The optical elements are arranged in parallel and configured to direct different images to the viewer's left and right eyes, thereby enabling stereoscopic perception without the need for special glasses. The apparatus further includes a memory configured to store computer-executable instructions and a processor configured to execute those instructions. The processor is operative to obtain, for any given pixel, a distance d between the pixel and a nearest end of a boundary that separates adjacent images. It then calculates a distance ratio D, defined as D=d/Lp, where Lp is the pitch of the optical element. Based on this distance ratio D, the processor determines an optimized brightness value B for the pixel using an S-shaped function. This function is continuously differentiable, monotonically increasing, approaches 0 as D approaches 0,approaches 1 as D approaches 1, and has an inflection point at D=0.5. This brightness modulation reduces crosstalk near image boundaries and improves the stereoscopic image quality presented to the viewer. In another preferred embodiment, there is provided an autostereoscopic display apparatus, comprising: an array of display pixels arranged in rows and columns; and an array of elongated optical elements extending parallel to one another and overlying the display pixels, wherein the optical elements are slanted at an angle relative to the columns of display pixels; for any given display pixel, an optimized brightness is determined based on the distance from the given pixel to the nearest end of a boundary separating adjacent images. In a preferred embodiment, the adjacent images include a plurality of pixel sets, and through which the pixel sets are viewed, the optical elements acting as optical directing means to provide separate images to a viewer's eyes, thereby providing an autostereoscopic display to the viewer. In another preferred embodiment, the optical element is a liquid crystal lens, including a plurality of lens units which repeatedly create groups of display pixels separated by boundaries between adjacent images. In one embodiment, starting from the pixels near said boundary, the brightness of each pixel is progressively increased. In another embodiment, a system for providing separate images to a viewer's eyes to thereby provide an autostereoscopic display to the viewer, the system comprising: an autostereoscopic display apparatus comprising means for producing a display which comprises an array of display pixels arranged in rows and columns, and an array of elongated lenticular elements extending parallel to one another overlying the display pixel array and through which the display pixels are viewed, the lenticular elements acting as optical directing means to provide separate images to a viewer's eyes to thereby provide an autostereoscopic display to the viewer, the lenticular elements having a pitch greater than a distance from the pixel to the nearest end of a boundary between adjacent images in the row direction. In another embodiment, the autostereoscopic display apparatus consists of a display pixel array arranged in rows and columns. Above this array, an array of elongated optical elements (e.g., lenticular lenses or liquid crystal lenses) is positione