WO2014155362A2

WO2014155362A2 - Viewing objects through a transparent display and backlight

Info

Publication number: WO2014155362A2
Application number: PCT/IB2014/060278
Authority: WO
Inventors: Udayan Kanade; Sanat Ganu
Original assignee: Udayan Kanade
Priority date: 2013-03-28
Filing date: 2014-03-28
Publication date: 2014-10-02
Also published as: WO2014155362A3

Abstract

A system comprising a display, a transparent backlight and a cavity containing objects is disclosed. In a given mode, the backlight is switched off in order to make it transparent and the objects in the cavity when lit up using lamps are viewable through the display and the backlight. In another mode, when the backlight is switched on it functions as a normal backlight for a display and images can be shown on the display. Various intermediate modes of operation have also been specified. Such a system can be used as a showcase.

Description

VIEWING OBJECTS THROUGH A TRANSPARENT DISPLAY AND BACKLIGHT

This application claims priority from provisional patent application 1171/MUM/2013 titled "Viewing Objects Through a Transparent Display and Backlight" filed in Mumbai, India on 28 Mar 2013.

The following eleven patent applications whose details are specified in the table below are incorporated herein by reference.

Sr. No.	Patent Title	PCT Publication No	PCT Publication Date
1	An Apparatus and Method for Providing a Light Source in the Form of a Surface	WO 2007/047684 A2	26 April 2007
2	Combined Video Display and Camera System	WO 2007/047685 A2	26 April 2007
3	Extraction of Light from a Light conducting Medium in a Preferred Emanation Pattern	WO 2007/140347 A2	6 December 2007
4	Display With Selectable Viewing Angle	WO 2007/140345 A2	6 December 2007
5	Light Source Having Transparent Layers	WO 2009/006640 A1	8 January 2009
6	Light Source of Varying Thickness	WO 2009/004598 A2	8 January 2009
7	A Polarized Linear Light Source	WO 2009/116013 A2	24 September 2009
8	A Directional Linear Light Source	WO 2009/116012 A2	24 September 2009
9	Photoluminescent Light Source	WO 2009/116014 A1	24 September 2009
10	Light Source Comprising Light Deflecting Particles	WO 2010/128481 A2	11 November 2010
11	Light Source Using a Photoluminescent Plate	WO 2013/027170 A2	28 February 2013

Technical Field

This invention relates to the field of displays. More particularly, it relates to the field of transparent displays through with objects can be viewed.

Background Art

Showcases are used in shops and stores to display products to be sold and are usually transparent.

Summary

The above and other preferred features, including various details of implementation and combination of elements are more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular methods and systems described herein are shown by way of illustrations only and not as limitations. As will be understood by those skilled in the art, the principles and features described herein may be employed in various and numerous embodiments without departing from the scope of the invention.

Brief Description of the Drawing

The accompanying drawing, which is included as part of the present specification, illustrates the presently preferred embodiment and together with the general description given above and the detailed description of the preferred embodiment given below serves to explain and teach the principles of the present invention.

Figure 1 depicts a system of the present invention, according to an embodiment.

Detailed Description

Figure 1 depicts a system 199 of the present invention, according to an embodiment. Display 101 is a display, which may be a liquid crystal display panel. The transparency of each pixel of the display 101 can be configured from a setting of almost opaque to some maximum transparency possible. The pixel may comprise sub-pixels each having a different color filter. The display 101 is of a kind such that whatever light is allowed by the display 101, is primarily allowed through without dispersion, i.e. the display 101 has clarity in any partially transparent state.

Backlight 103 is a transparent backlight. The backlight 103 sources light into the display 101, but is also transparent to light falling on it. The backlight 103 can source various amounts of light. When it is sourcing no light, it seems completely transparent, i.e. almost invisible. When it is sourcing light, the more the light, the more difficult it is to see through the backlight 103. The physical transparency or clarity of the backlight 103 does not reduce, but the light makes it difficult to observe through it.

One or more lamps 105 are a source of light placed in cavity 107. Lamps 105 illuminate cavity 107 and objects 109 placed in cavity 107. The cavity 107 and objects 109 together form scene 111. Lamps 105 may be a single or multiple light sources illuminating the scene 111 in various ways. E.g. each object of the objects 109 may have an independently controllable light source illuminating that object. The lamps 105 may be embedded in the ceiling of the cavity 107, on the sides of the cavity 107, at the back of cavity 107 or may be an illuminated floor, ceiling or backdrop.

The display 101 and backlight 103 form one wall of the cavity 107. The cavity 107 may be an enclosed cavity, or may be partially open. The backlight 103 is placed parallel to the display 101, between the display 101 and cavity 107.

In one mode, the backlight 103 is completely off, and one or more of the lamps 105 are sourcing some light. In this mode, the scene 111 will be visible through the display 101, and an observer will be able to perceive the scene 111 through the display 101. The display 101 may be kept at it's maximum transparency so that only the scene 111 is perceived by a viewer. Alternatively, the display 101 may be displaying text, graphics, videos, etc., which will seem superimposed on the scene 111. This may be used, for example, to display an object such as a consumer product and display information about it at the same time. The user may interact with the system through a touchscreen (integrated into the display 101) or through gestures, mouse, keyboard, keypad, etc., and such input may be used to change the display, or change the lighting condition, or to create other changes in the scene 111 such as moving objects 109, changing the matter on the displays on the objects 109, etc.

In another mode, the backlight 103 is sourcing light, and the lamps 105 are sourcing no light. In this mode, the scene 111 will become almost invisible, and the display 101 will be perceived as a normal display. In this mode, a normal operation of the system, such as showing images, text, videos, graphics, informative content, interactive content is possible.

The switching between the modes where the scene 111 is displayed and only the display 101 is perceived may be performed gradually, so that a continuous fade is achieved. Intermediate states may also be maintained indefinitely. For example, the lamps 105 may source light in a dimmed state, and the backlight 103 may be partially or fully turned on, to give an effect that the scene 111 is still visible, but with lesser contrast than before. In this way, the clarity of displayed matter is increased while keeping the scene 111 in the background but without removing it completely.

Behind the backlight 103 (but ahead of the cavity 107), a partial mirror may be placed. This will increase the efficiency of the backlight 103, but also increase the amount of light that the lamps 105 have to source to achieve a certain illumination level for scene 111. Alternatively, in this position, a switchable mirror may be placed. This can switch between a reflective and transmissive mode. The reflective mode may be most beneficial when the backlight 103 is on, and the transmissive mode may be most beneficial when the lamps 105 are on.

In this same position, a switchable diffuser may also be placed. A switchable diffuser switches between a diffusing mode and a transmissive mode. In highly diffusing mode, the switchable diffuser acts like a diffuse reflector, thus increasing the efficiency of the backlight 103. In transmissive mode, it becomes completely transparent, and this is useful when the lamps 105 are on and the scene 111 is illuminated. The switchable diffuser may also be kept in a partly diffusing mode so that the scene 111 becomes less pronounced without disappearing completely. This will also increase the clarity of the displayed matter, and can be used together with the mode where the backlight 103 is completely or partially on. The lamps 105 may be dimmed for further reduction in definition of scene 111.

In an embodiment, the backlight 103 is segmented into multiple independent backlights. With individual control, sections of the backlight can now be made to source light or seem transparent. In this way, effects such as making one part of the display display matter whereas keeping the scene visible in another part are possible. Individual control over the primary light sources of the backlight may also be provided. Since each light source of the primary light sources has effect over a certain area of the backlight, only a certain area of the backlight will emanate light, which may be used for special ornamental effects.

AUTHORING SYSTEM

Various authoring systems for content on displays and multimedia presentations are well known in the art. For example, Macromedia Flash, HTML5 with Javascript and many tools written for authoring such content, etc. are well known. In an embodiment of the present invention, an authoring system also allows control of the scene 111. For example ways of controlling the lamps 105 and other behaviors of the objects 107 may be provided. For example, a Javascript or Actionscript API for controlling lights may be provided as a base API. An authoring tool may make it easy to integrate such actions into the “script” of an interactive animation. For example, a frame or slide based authoring tool will allow authoring of not only screen content, but also scene content. Various transitions between such frames or slides will be possible, such as fading, in betweening etc. A scripting language will be able to control the playing of such animation, and also control individual elements of the screen content and scene content.

The authoring system will also have a simulator which will simulate the appearance of the entire apparatus, including scene and display and allow the programmed interactions with the apparatus. In this way, the authoring of content can be done without the scene and apparatus being physically present.

OTHER EMBODIMENTS

In an embodiment, the transparent backlight emanates light in only one direction. It may be preferred to emanate the light in the direction of the display, thus increasing the efficiency of the backlight. Another transparent backlight emanating light only in the direction of the scene may be included to achieve good front-lighting of the objects in the scene.

In an embodiment, a transparent backlight emanating light in a narrow cone of angles is present. In this way, only a person standing in a particular location will be able to perceive the light from the backlight. In an embodiment, more than one transparent backlights are present, some emanating light in a narrow cone of angles and some emanating light in a broad cone of angles. Which backlight to choose may be controlled by the software system, or may be chosen based on a sensing of the number and angle of observers.

The display need not be placed at a vertical side of the cavity. The display could be the top surface of the cavity, and viewed from top. The display could be slightly slanted to provide ease of viewing and controlling by a user. Thus the cavity is a box with a slightly tilted top (such as many show-cases), and the slightly tilted top is a display.

In an embodiment, the transparent backlight is not present, but a switchable diffuser is present behind the display 101. When the diffuser is transparent, the scene 111 is seen when lit by lamp 105. When the diffuser is in diffusing mode, the scene 111 becomes diffuse, and direct and indirect light from lamp 105 diffused by the switchable diffuser lights the display 101. Furthermore, a special lamp trained onto the switchable diffuser may be provided inside the cavity 107. When the diffuser is in transparent mode, the special lamp is off. When the diffuser is in diffusing mode, the special lamp sends lights onto it which diffuses and emanates out of the display 101.

In an embodiment, the display 101 produces color by color filters, such as liquid crystal display producing colors by applying color filters on sub-pixels. The color filters may be kept very unsaturated, i.e. each color filter allows a large range of frequencies to pass. The backlight 103 itself carries a mixture of three highly bandlimited (narrowband) light frequencies groups / saturated colors. The color saturation achieved when the display 101 is lit by scene 111 will be low, but efficiency will be high. The color saturation achieved when the display 101 is lit by backlight 103 will be high. In another embodiment, each sub-pixel filter of the display 101 has two narrowband notches, to absorb two of the three narrowband light groups, and allows the third group to pass. Different sub-pixel filters allow different of the three groups to pass. In this way, high efficiency is achieved when the display 101 is lit by the scene 111, and good saturation is achieved when the display 101 is lit by backlight 103. In an embodiment, the amount of individual colors in the backlight is independently controllable, giving further efficiency and rise to novel colored light effects.

In an embodiment, a switchable diffuser is kept in between the backlight 103 and the display 101. This may be in addition to the switchable diffuser between the scene 111 and backlight 103, or it may be the only switchable diffuser present. (6) In an embodiment, the diffuser between the scene 111 and backlight 103 (if present) is segmented in the same way that the backlight 103 itself is segmented. But the switchable diffuser between the backlight 103 and display 101 has a single segment which spans the entire display 101. The front (single segment) switchable display is used to reduce segment boundary defects when the multiple segments are all turned on to illuminate the entire display 101. The back (multi-segmented) switchable diffuser is used in tandem with the backlight 103. A particular segment of the backlight 103 is turned on and the corresponding segment of the switchable diffuser is made diffusing at the same time.

Each segment of the backlight, each segment of the one or more switchable displays, the various scene lights can all be controlled independently in the present invention for achieving various effects. Some modes of the present invention are (i) both scene and backlight are off, (ii) scene light is on, (iii) backlight is on and (iv) both scene and backlights are on. In each of these modes, the diffuser can be kept to be clear or diffusing. Furthermore, any intermediate mode between these eight modes can be achieved and maintained. The apparatus can transition smoothly between such modes or such states.

In an embodiment, a cavity has more than one transparent displays oriented in the same or various directions. Some or all of the transparent displays have transparent backlights behind them, and may have switchable diffusers behind them. In an embodiment, the backlight of one display acts as the scene light of another display and vice versa. The overall media on the displays is managed such that the requirement of backlight when viewing through one display matches the requirement of the scene light when viewing through another display. This embodiment is beneficial when the cavity may be viewed from various directions, such as shop windows, show cases, rotating displays, etc.

In an embodiment, a camera is placed in the cavity 107 such that it can capture an image through the display 101 and transparent backlight 103. In scene lit mode the camera can continuously capture through the display 101, or to reduce leakage from the light source 105, the light source 105 is switched on alternately with the camera capturing an image. This alternation can happen at a very fast rate so that it is imperceptible to a human. Similarly, in backlit mode, the backlight 103 can switch on and off at a very fast rate imperceptible to the human eye. This alternates with the camera recording an image, so that camera captures a clear image. The display 101 may also alternate between showing an image and transparent, where the transparent mode coincides with the camera capturing an image. The switchable diffuser, if present, may also switch between diffusing mode and transparent mode where the transparent mode coincides with the camera capturing an image.

With the presence of a camera, the apparatus may be used as a showcase which converts into a virtual mirror. The virtual mirror displays the image of the person captured by the camera on the display itself. If the cavity has apparel, jewelery, etc., both that item as well as the image of the person may be shown by optimal use of the backlight and scene light. Thus, the person may position himself or herself in such a fashion as to observe how the apparel / jewelery will seem on that person. In another embodiment, an algorithm is used to create an image of the person wearing the clothes or jewelery, etc. This image is displayed on the virtual mirror.

In an embodiment, the scene light 105 and backlight 103 are turned on alternately at a rate that is imperceptible to humans. The display 101 displays different images for when the scene light 105 is turned on and when the backlight 103 is turned on. The image displayed when the scene light 105 is on filters the scene 111, and the image displayed when the backlight 103 is on gets added to this filtered scene image at the eye due to persistence of vision. Thus, additive display of the scene and an image can be achieved. A camera, if one exists, may be turned on during the scene display phase, or the camera may have its own phase when both the lights are turned off.

In an embodiment, the backlight 103 emits ultraviolet light. The pixels of the display 101 allow or block this ultraviolet light. This light then falls on phosphorescent dots in front of the pixels, which convert it into various visible colors (usually red, green and blue). In this way, color filters are not required and the efficiency is thus increased.

In another embodiment, the backlight 103 cycles between emitting various colors (usually red, green and blue) at a rate imperceptible to humans. The display pixels display images appropriate for the three colors. In this way color filters are not required, thus increasing the transparency and efficiency of the display 101. There may be a fourth phase of turning the scene light on that alternates with the three colors, and this phase may also have a camera capturing an image, or there may be a fifth phase of a camera capturing an image.

In an embodiment, the switchable diffuser is pixelated. One way to make a switchable diffuser is to sandwich an element that can turn clear or diffusing depending on the state of an electric field applied across it between electrodes. For example, a suspension of liquid crystal domains in a transparent solid where the refractive indexes of both are arranged in a particular fashion can be such an element. A pixelated diffuser can be created by having multiple electrical domains across such an element. Passive and active matrix technology can create domains of electric fields. These technologies can be applied to a switchable diffuser element to create a diffuser which can be controlled pixel by pixel instead of just one state overall. This can be used by media designers to achieve novel effects such as turning the diffuser on behind displayed elements to make them seem to have a translucent quality whereas keeping other areas transparent. For example if a window, a control or a widget pops up on the display, the diffuser pixels exactly behind it can be made translucent to increase the clarity of the popped up object while maintaining the presence of the objects behind.

In an embodiment, applying passive or active matrix technology to a switchable diffusing element comprises using the electrical elements of a passive matrix or active matrix display on a switchable diffusing element. Tracks of a transparent material such as ITO (or thin tracks of a conductor) may be laid on one or both sides of the switchable diffusing element. Transistors may be created on one side for active matrix. Some electronics can be created on plastics, which may be the substrate. Alternately, glass could be used as the substrate in which the liquid crystal domains are suspended. Alternately, the substrate could be plastic or some transparent material and glass could be applied on one or both sides of this substrate for creating the electronics.

A system comprising a display, a transparent backlight and a cavity containing objects is disclosed. It is understood that the embodiments described herein are for the purpose of elucidation and should not be considered limiting the subject matter of the present patent. Various modifications, uses, substitutions, recombinations, improvements, methods of productions without departing from the scope or spirit of the present invention would be evident to a person skilled in the art.

Claims

An apparatus comprising a display, a transparent backlight placed behind the display and a cavity containing objects placed behind the transparent backlight.
The apparatus of claim 1, further comprising one or more lamps that are used to light up the cavity.
The apparatus of claim 2, wherein a first mode of operation comprises switching off the transparent backlight and switching on the one or more lamps.
The apparatus of claim 2, wherein a second mode of operation comprises switching on the transparent backlight and switching off the one or more lamps.
The apparatus of claim 1, wherein the display is a liquid crystal display and transparency of each pixel of the display is configurable.
The apparatus of claim 1, wherein the transparent backlight sources light into the display, and is also transparent to light falling on it from outside.
The apparatus of claim 1, further comprising a switchable mirror placed in between the transparent backlight and the cavity.
The apparatus of claim 1, further comprising a switchable diffuser placed in between the transparent backlight and the cavity.