Microfaceted projection screen

To avoid requiring precise alignment between a projector and a projection screen, plural micro etched faceted grooves are provided for each area of the screen onto which a single pixel is to be projected. Each facet may be roughened, or gently curved, and the walls between adjoining facets likewise may be curved.

FIELD

The application relates generally to projection screens for short throw projectors.

BACKGROUND

With some video projectors, and especially short throw projectors, much of the projected light ends up being reflected toward the ceiling from the projection screen.

SUMMARY

A projection screen is formed with micro-facets that reflect light from a projector toward the viewers of the screen without the need for lenticular lenses to do this.

In an aspect, an apparatus includes a projection screen onto which pixels from a projector are to be projected. Each pixel from the projector corresponds to a small area on the projection screen, which may be referred to as a “pixel area”. Within each of the pixel areas, plural micro grooves are on the projection screen reflect the light toward the viewer.

Each pixel from the projector corresponds to a respective pixel area on the projection screen. In each of at least plural of the pixel areas, plural micro grooves are formed on the projection screen.

In some examples, plural micro grooves are formed in each of at least ninety percent of the pixel areas. Plural micro grooves may be formed in each of all of the pixel areas.

Thus, in some examples a set of micro grooves is formed, with each micro groove containing a set of faceted features in which the vertical and horizontal orientation of each individual facet are aligned to reflect light from a projector toward the expected position of a viewer of the screen. The orientation angles in both the vertical and horizontal directions may vary for each facet to accommodate the changing angle of the light from the projector across the projection screen. The facet orientation angles thus may not be equal between facets because their relative position to the projector will be different. Note further that for each facet, the height and width of the facet may change across the surface of the projection screen.

In example embodiments, in at least a first pixel area of the plural pixel areas, at least first and second micro grooves are formed. The first micro groove is above the second micro groove, and the first micro groove defines a first angle with respect to vertical. The second micro groove also defines a second angle with respect to vertical, and the first and second angles are not equal.

In non-limiting implementations, in at least a first pixel area of the plural pixel areas, at least first and second micro grooves are formed. The first micro groove is above the second micro groove and defines a first angle with respect to horizontal. The second micro groove defines a second angle with respect to horizontal, and the first and second angles are not equal.

In examples, in at least a first pixel area of the plural pixel areas, at least first and second micro grooves are formed, and at least the first micro groove being formed with a roughened surface.

In some embodiments, in at least a first pixel area of the plural pixel areas, at least first and second micro grooves are formed, and at least the first micro groove is formed with a curvilinear surface.

If desired, in at least a first pixel area of the plural pixel areas, at least first and second micro grooves can be formed. A connecting wall between facets may be formed with a curvilinear surface.

In another aspect, an assembly includes a projection screen and a projector projecting video pixels onto respective pixel areas on the projection screen. At least one pixel area includes plural grooves that are parallel to each other.

In another aspect, a method includes forming a projection screen with plural micro grooves, and providing a projector for projecting video pixels onto the projection screen. Each one of at least some of the pixels is projected onto plural micro grooves when the projector projects images onto the screen.

The details of the present application, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:

DETAILED DESCRIPTION

This disclosure relates generally to computer ecosystems including aspects of consumer electronics (CE) device networks such as projector systems. A system herein may include server and client components, connected over a network such that data may be exchanged between the client and server components. The client components may include one or more computing devices including video projectors and projector screens, portable televisions (e.g. smart TVs, Internet-enabled TVs), portable computers such as laptops and tablet computers, and other mobile devices including smart phones and additional examples discussed below. These client devices may operate with a variety of operating environments. For example, some of the client computers may employ, as examples, operating systems from Microsoft, or a Unix operating system, or operating systems produced by Apple Computer or Google. These operating environments may be used to execute one or more browsing programs, such as a browser made by Microsoft or Google or Mozilla or other browser program that can access web applications hosted by the Internet servers discussed below.

A processor may be any conventional general purpose single- or multi-chip processor that can execute logic by means of various lines such as address lines, data lines, and control lines and registers and shift registers.

Software modules described by way of the flow charts and user interfaces herein can include various sub-routines, procedures, etc. Without limiting the disclosure, logic stated to be executed by a particular module can be redistributed to other software modules and/or combined together in a single module and/or made available in a shareable library.

Further to what has been alluded to above, logical blocks, modules, and circuits described below can be implemented or performed with one or more general purpose processors, a digital signal processor (DSP), a field programmable gate array (FPGA) or other programmable logic device such as an application specific integrated circuit (ASIC), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A processor can be implemented by a controller or state machine or a combination of computing devices.

Now referring toFIG. 1, a micro groove projection screen101is shown, the grooves of which may be established by etching or other appropriate process. As shown by the zoomed in portion102, showing an example of the micro groove size relative to the size of the areas103(four shown) of the screen101onto each one of which is projected a single pixel from a projector such as a short throw projector, each projected pixel covers an area of the display101with a large number of micro etched grooves104. This reduces or eliminates the need for a precise alignment between the projection screen and the projector. The number of grooves104is greater than one per pixel and may be between four and sixteen grooves per pixel area, although other numbers may be used.

Thus, the projection screen101onto which pixels from a projector are to be projected has pixel areas103, with each pixel from the projector corresponding to a respective pixel area103on the projection screen in a one-to-one relationship. In each of at least plural of the pixel areas103, plural micro grooves104are formed on the projection screen.

In some examples, plural micro grooves are formed in each of at least ninety percent of the pixel areas. Plural micro grooves may be formed in each of all of the pixel areas103. Note that as shown inFIG. 1, the grooves104are parallel to each other.

The grooves104may be created through a process such as laser micro ablation. In addition, alternate manufacturing methods include mechanical press (similar to what's been used for music CDs) and nano-scale3D printing. These techniques may be used in combination where a metal master made by laser ablation is used to press the micro faceted groove pattern onto another material. For various press methods, a negative image of the faceted micro grooved surface is created such that when pressed into a material it result in a positive version being imparted to the material being pressed. The press methods include a flat plate press and a roll press where material is passed under a large roller which has several copies of the negative master. As the material passed through the roll press the faced groove pattern is imparted to it.

Turning toFIG. 2, showing a side view of part of the screen101, the etched grooves104may be controlled on a row by row basis to have differing angles to ensure even and directed brightness of the light202reflected to the viewer from, e.g., a short throw projector. The angle of the light from the projector with respect to the screen101varies evenly between a top portion203of the projection screen and a bottom portion204of the projection screen. The angles of the facets of the grooves104vary accordingly row by row to accommodate the differing angles of incidence from the projector. InFIG. 2the size of the grooves and the angles are exaggerated for purposes of illustration of the accommodation of the angle of light from the short throw projector.

Thus, as shown inFIG. 2, in at least a first pixel area of the plural pixel areas103shown inFIG. 1, at least first and second micro grooves are formed, with the first micro groove being above the second micro groove. The first micro groove defines a first angle β with respect to horizontal210, and the second micro groove defines a second angle α with respect to horizontal, with the first and second angles not being equal. The second (lower) angle may be less acute than the first (higher) angle.

FIG. 3shows a top view of a projection screen101, showing how the surface within each of the etched grooves104may be further micro faceted to ensure even brightness of the light302reflected from a projector such as a short throw projector. The angle of the light from the projector, particularly a short throw projector, can vary between the left side304and right side303of the screen. Note that the left side304and right side303designations are from the viewpoint of looking at the projection screen from the front. There is a gradual change of the angles of facets between successive grooves104between the left side304and the right side303of the screen to accommodate the changing angle of the light302from the projector.

Thus, as shown inFIG. 3, in at least a first pixel area103of the plural pixel areas, at least first and second micro grooves are formed, the first micro groove being adjacent the second micro groove. The first micro groove defines a first angle α with respect to the normal310to the screen surface, with the second micro groove defining a second angle β with respect to the normal, and with the first and second angles not being equal. For example, the laterally inboard angle (in the example shown, α) can be less acute than the laterally outboard angle (in the example shown, β).

FIG. 4illustrates the two-dimensional faceting described above in reference toFIGS. 2 and 3. An example close up view402of a small section of the upper left corner of the projection screen101illustrates how the individual facets created with the micro grooves direct light from the short throw projector along both the vertical and horizontal axis.

FIG. 5shows a single micro groove104in which a micro facet501within each groove may optionally have a microscopically rough surface502to provide light scattering to increase the field of view. The roughness is at a very small scale relative to the facet size. The roughness may be created through the manufacturing process or by a coating applied to the surface to provide photon scattering. Alternatively, the facet surface may be kept smooth and/or polished to maximize light being reflected toward a selected area where the viewer is expected to be. Variations between these extremes are also possible. An additional surface coating may be applied over the finished projection screen as a protectant for when the projection screen is cleaned. The index of refraction for the protective coating may be made to be close to the index of refraction for regular air.

FIG. 6shows a single micro groove104with a corresponding facet601that can be formed with a slight outward bulge602relative to the center of the facet in order to widen the viewing angle of the projection screen. This can optionally be combined with the surface roughness method shown inFIG. 5. Thus, a micro groove can be formed with a curvilinear surface.

FIG. 7shows a single micro groove104with a facet701and an opposite wall702extending from the groove104to the facet701of an adjacent groove. As shown, the wall702has a curvilinear surface such as a concave bend and/or is constructed at an angle to ensure that it will not interact with the light703from the projector.

Now specifically referring toFIG. 8, an example ecosystem10is shown, which may include one or more of the example devices mentioned above and described further below in accordance with present principles. The first of the example devices included in the system10is a projection screen assembly12. The projection screen assembly12can be established by some or all of the components shown inFIG. 8and may any of the micro groove screens described previously. The projection screen assembly12may include an active display or screen in that it contains addressable screen elements that establish screen pixels and that can be controlled to establish grayscale values. Or, the assembly12may be a passive screen. When implemented by an active screen for, e.g., establishing grayscale values on the screen itself in coordination with color light projected onto the screen from the projector, the techniques described in the present assignee's U.S. Pat. No. 9,640,143, incorporated herein by reference, may be used.

The projection screen assembly12can include one or more microfaceted screens or displays14. The projection screen assembly12may also include one or more speakers16for outputting audio in accordance with present principles.

For active screen assemblies, the assembly can include at least one input device18such as e.g. an audio receiver/microphone or key pad or control keys for e.g. entering commands to at least one screen processor20. An example active screen assembly12may also include one or more network interfaces22for communication over at least one network24such as the Internet, an WAN, an LAN, etc. under control of the one or more processors20. Thus, the interface22may be, without limitation, a Wi-Fi transceiver, which is an example of a wireless computer network interface, such as but not limited to a mesh network transceiver, or it may be a Bluetooth or wireless telephony transceiver. It is to be understood that the processor20may control the screen assembly12. Furthermore, note the network interface22may be, e.g., a wired or wireless modem or router, or other appropriate interface such as, e.g., a wireless telephony transceiver, or Wi-Fi transceiver as mentioned above, etc.

In addition to the foregoing, an active screen assembly12may also include one or more input ports26such as, e.g., a high definition multimedia interface (HDMI) port or a USB port to physically connect (e.g. using a wired connection) to another CE device and/or a headphone port to connect headphones to the screen assembly12for presentation of audio from the screen assembly12to a user through the headphones. For example, the input port26(and/or network interface22) may be connected via wire or wirelessly via the network24to a cable or satellite or other audio video source28with associated source processor28A and source computer memory28B. Thus, the source may be, e.g., a separate or integrated set top box, or a satellite receiver. Or, the source28may be a game console or personal computer or laptop computer or disk player. Yet again, the source28and/or the color video source discussed below may be cloud servers on the Internet, and may include and perform “cloud” functions such that the devices of the system10may access a “cloud” environment via the server28in example embodiments. Or, the server28may be implemented by a game console or other computer in the same room as the other devices shown inFIG. 5or nearby.

An active screen assembly12may further include one or more computer memories30such as disk-based or solid state storage that are not transitory signals, in some cases embodied in the chassis of the screen as standalone devices or as a personal video recording device (PVR) or video disk player either internal or external to the chassis of the AVDD for playing back AV programs or as removable memory media.

Still referring toFIG. 8, in addition to the AVDD12, the system10may include one or more other device types. When the system10is a home network, communication between components may be according to the digital living network alliance (DLNA) protocol. Or, the projector and screen can be used in a public movie theater.

In one example, a front projector32such as but not limited to a Sony ultra short throw (UST) projector may be used to project demanded images onto the front of the display14. The example projector32may include one or more network interfaces34for communication over the network24under control of one or more projector processors36. Thus, the interface34may be, without limitation, a Wi-Fi transceiver, which is an example of a wireless computer network interface, including mesh network interfaces, or a Bluetooth transceiver, or a wireless telephony transceiver.

It is to be understood that the projector processor36controls the projector32to undertake present principles. In this regard, the projector processor36may receive signals representing demanded color images from a color video source38which may be the same as or different from the video source28described previously and which may be established by any one or more of the source types described previously.

The projector processor36controls a lamp assembly40to project color light onto the screen assembly12. The lamp assembly may be a laser lamp assembly or other type of color illuminator assembly. The projector may further include one or more computer memories42such as disk-based or solid state storage.

As shown inFIG. 8, the screen12may be mounted on a substrate44such as but not limited to a wall or window.

The above methods may be implemented as software instructions executed by a processor, including suitably configured application specific integrated circuits (ASIC) or field programmable gate array (FPGA) modules, or any other convenient manner as would be appreciated by those skilled in those art. Where employed, the software instructions may be embodied in a device such as a CD Rom or Flash drive or any of the above non-limiting examples of computer memories that are not transitory signals. The software code instructions may alternatively be embodied in a transitory arrangement such as a radio or optical signal, or via a download over the internet.

It will be appreciated that whilst present principals have been described with reference to some example embodiments, these are not intended to be limiting, and that various alternative arrangements may be used to implement the subject matter claimed herein.