US 11,754,854 B2
Head mounted display device
Meng-Che Tsai, Taoyuan (TW); and Kuei-Chun Liu, Taoyuan (TW)
Assigned to HTC Corporation, Taoyuan (TW)
Filed by HTC Corporation, Taoyuan (TW)
Filed on Jun. 18, 2021, as Appl. No. 17/351,264.
Prior Publication US 2022/0404636 A1, Dec. 22, 2022
Int. Cl. G02B 30/35 (2020.01); G02B 30/36 (2020.01); G02B 27/14 (2006.01); H04N 13/344 (2018.01)
CPC G02B 30/35 (2020.01) [G02B 27/149 (2013.01); G02B 30/36 (2020.01); H04N 13/344 (2018.05)] 7 Claims
OG exemplary drawing
 
1. A head mounted display device, comprising:
a first display, projecting a first image to a first target area;
a second display, projecting a second image to a second target area;
a third display, projecting a third image; and
an optical element, disposed among the first target area, the second target area, the first display, the second display, and the third display, wherein the optical element transmits the first image to the first target area, transmits the second image to the second target area, and reflects the third image toward the first target area and the second target area, the optical element comprising:
a first beam splitter, disposed between the first target area and the first display;
a first lens, disposed between the first beam splitter and the first display;
a second beam splitter, disposed between the second target area and the second display;
a second lens, disposed between the second beam splitter and the second display;
a third beam splitter, being an X-shaped beam splitter, disposed between the first beam splitter and the second beam splitter; and
a third lens, disposed between the third beam splitter and the third display,
wherein a focal length of the third lens is different from a focal length of the first lens and a focal length of the second lens,
wherein a depth of field of the third image is greater than a depth of field of the first image and a depth of field of the second image so as to reduce the vergence-accommodation conflict of a user.