# US 11,451,764 B2 · Method and device for the simultaneous projection of individual images for a plurality of viewers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,451,764 B2 - Document ID: US11451764B2 - Status: Granted - Kind: B2 - Application number: 17/307,932 - Filed: 2021-05-04 - Published: 2021-11-11 - Granted: 2022-09-20 - Earliest claimed: 2020-05-06 - Assignees: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. - Applicants: Fraunhofer-Gesellschaft Zur FöRderung Der Angewandten Forschung E. V. - Inventors: Matthias Bues; Benjamin Wingert - Web page: https://patentgrep.com/patent/US11451764B2 ## CPC - H04N 13/363: using image projection screens (volumetric display H04N13/388) - H04N 13/324: Colour aspects - H04N 13/341: using temporal multiplexing - H04N 13/354: for displaying sequentially - H04N 2013/40: {Privacy aspects, i.e. devices showing different images to different viewers, the images not being viewpoints of the same scene} - H04N 2013/405: {the images being stereoscopic or three dimensional} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Disclosed are a method and a device by which individual images can be displayed simultaneously to a plurality of observers. In this process, projectors can be used that project the colors from which the images are assembled following one another periodically in time. ## Claims ### Claim 1 A method for the simultaneous projection of individual images for a plurality M of viewers, wherein each image Bm, m=1, M, is respectively either a partial image Tm a, a ϵ{left, right} for a right eye and a left eye of the viewer m for a viewer m or is a partial image Tm a=both for both eyes of a viewer m; wherein each partial image Tm a is assembled from N, Nϵ and N≥2, color components Fm a c, c=1, . . . , N of different colors; wherein N projectors Pn, n=1, . . . , N, in each case project color components of the part images in temporally consecutive time intervals ti; wherein each projector projects all N colors of color components periodically temporally in a fixed order after one another; wherein the N projectors together project all color components Fm a c, c=1, . . . , N, of a partial image Tm a for one or both eyes a of one of the viewers m in every time interval ti; and project all the partial images Tm a of both eyes a of all the viewers m once in the course of a period; wherein a filter that can be switched between transparent and opaque is assigned to each eye a, a ϵ (left, right, both) of each viewer; and wherein the respective filter assigned to the eye a of the viewer m is switched to transparent in the time interval ti in which the projectors display the color components of the partial image Tm a. ### Claim 2 (depends on 1) The method in accordance with claim 1, wherein all the projectors project the N colors of the components in the same order, but offset in time from one another. ### Claim 3 (depends on 1) The method in accordance with claim 1, wherein a number of partial image signals equal to the number Tm a that represent the partial images Tm a are provided by a signal source, and wherein the respective N color components of the partial image signals are distributed over the N projectors in that the N color components of this image signal are supplied to different ones of the projectors for each of the partial image signals. ### Claim 4 (depends on 1) The method in accordance with claim 1, wherein the method is a method for the simultaneous projection of individual stereoscopic images for the plurality of viewers, wherein each image Bm, m=1, . . . , M, for one of the viewers m is respectively either a partial image Tm a, a ϵ{left, right} for a right eye and a left eye of the viewer m; wherein the N projectors together project all color components Fm a c, c=1, . . . , N, of a partial image Tm a for exactly one eye a of one of the viewers m in every time period ti; and project all the partial images Tm a of both eyes a of all the viewers m once in the course of a period; wherein a filter that can be switched between transparent and opaque is assigned to each eye a, a ϵ{left, right, both} of each viewer; and wherein the respective filter assigned to the eye a of the viewer m is switched to transparent in the time interval ti in which the projectors display the color components of the partial image Tm a. ### Claim 5 (depends on 4) The method in accordance with claim 4, wherein the delay of the color components supplied to the projector Pn is effected in that the color components supplied to the projector Pn are led through a first-in first-out memory in which n-1 time intervals are buffered. ### Claim 6 (depends on 1) The method in accordance with claim 1, wherein the number of color components is N=3 and/or the number of viewers is M=3. ### Claim 7 (depends on 1) The method in accordance with claim 1, wherein the number of the color components is N=3 and the number of the viewers is M=3 and the image signals are projected to the projectors as follows: Projector 1: L11, L22, L33, R11, R22, R33, . . . Projector 2: L12, L23, L31, R12, R23, R31, Projector 3: L13, L21, L32, R13, R21, R32, . . . where Lmc stands for the color component Fm left c for the left eye of the viewer m and Rmc for the color component Fm right c for the right eye of the viewer m. ### Claim 8 (depends on 1) The method in accordance with claim 1, wherein color components of the images for different eyes of the same viewer are supplied to the same one of the projectors. ### Claim 9 (depends on 1) The method in accordance with claim 1, wherein a respective filter for a right eye and a filter for a left eye of the same viewer are designed as spectacles. ### Claim 10 (depends on 1) The method in accordance with claim 1, wherein all projectors project the color components in the same order. ### Claim 11 (depends on 10) The method in accordance with claim 10, wherein each of the projectors has a color wheel that rotates in the optical path of a light source of the corresponding projector and has filter segments in the N color components along its periphery. ### Claim 12 (depends on 1) The method in accordance with claim 1, wherein all projectors are synchronized with one another so that each simultaneously projects a color component and projects the same colors pairwise offset by a time interval. ### Claim 13 (depends on 1) The method in accordance with claim 1, wherein the images Bm are frames of a moving image or of a film having M components for the M viewers. ### Claim 14 (depends on 1) A display device for the simultaneous projection of individual stereoscopic images for viewing by a plurality M of viewers, comprising N projectors, where N is the number of color components of the images to be projected; 2M filters that can each be switched between transparent and opaque, wherein the display device is configured to perform a method in accordance with claim 1. ### Claim 15 (depends on 13) A display device in accordance with claim 13, comprising a processor with which the method steps can be performed.