Patent Application
20140176671
This application claims priority to Republic of Korea Patent Application No. 10-2012-0148695 filed on Dec. 18, 2012, which is incorporated by reference herein in its entirety.
1. Field of the Disclosure
The present disclosure relates to an apparatus for displaying a hologram. Especially, the present disclosure relates to a holography three dimensional display.
2. Discussion of the Related Art
Recently, many technologies and research for making and reproducing 3D (Three Dimensional) image/video are being actively developed. As the media relating to the 3D image/video is a new concept media for virtual reality, it can improve visual information better, and it will lead the next generation display devices. The conventional 2D image system merely suggests the image and video data projected to plan view, but the 3D image system can provide the full real image data to the viewer. Thus, 3D image/video technologies are the True North image/video technologies.
Typically there are two methods for reproducing 3D image/video; the stereoscopy method and the autostereoscopic method. The stereoscopy method uses the binocular parallax caused by the human two eyes apart from each other. There are typically two types; one is the glasses type and the other is non-glasses type. For the glasses type, the display device displays the left eye image and the right eye image in different polarization directions or in time division manner. The observer can enjoy the 3D images using the polarization glasses or the liquid crystal shutter glasses. However, the glasses type has the disadvantage in that the user should wear the glasses in order to enjoy the 3D images.
For solving this disadvantage, a non-glasses type has been developed. The volumetric display type, one of non-glasses type, can suggest the scope and color information so that the observer can enjoy the 3D images at any positions freely.
To produce a recording of the phase of the light wave at each point in an image, holography method, one of volumetric display type, uses a reference beam, which is combined with the light from the scene or object (the object beam). If these two beams are coherent, optical interference between the reference beam and the object beam, due to the superposition of the light waves, produces a series of intensity fringes that can be recorded on standard photographic film. These fringes form a type of diffraction grating on the film, which is called the hologram. The central goal of holography is that when the recorded grating is later illuminated by a substitute reference beam, the original object beam is reconstructed (or reproduced), producing a 3D image/video.
There has been a new development of the computer generated holography (or CGH) that is the method of digitally generating holographic interference patterns. A holographic image can be generated e.g. by digitally computing a holographic interference pattern and printing it onto a mask or film for subsequent illumination by suitable coherent light source. The holographic image can be brought to life by a holographic 3D display, bypassing the need of having to fabricate a “hardcopy” of the holographic interference pattern each time.
Computer generated holograms have the advantage that the objects which one wants to show do not have to possess any physical reality at all. If holographic data of existing objects is generated optically, but digitally recorded and processed, and brought to display subsequently, this is termed CGH as well. For example, a holographic interference pattern is generated by a computer system and it is sent to a spatial light modulator such as LCSML (Liquid Crystal Spatial Light Modulator), then the 3D image/video corresponding to the holographic interference pattern is reconstructed/reproduced by radiating a reference beam to the spatial light modulator.
Referring to
For the case that the hologram is reproduced based on the LCD device, the pixel pitch of the LCD is too large to view the angle for seeing the hologram correctly. Therefore, the observer only can see the hologram 3D images within a very small view angle.
An apparatus for displaying hologram images comprises: a hologram display panel that represents light having the hologram images to an observer; a detecting camera that decides a position of the observer; a deflector that forms a prism pattern to refract the light corresponding to the detected position of the observer; and a deflector driver that supplies a driving voltage corresponding to a inclined angle for forming the prism pattern, wherein the deflector includes: a plurality of first electrodes running to a first direction and divided into a plurality of electrode groups; a plurality of connection electrodes running to a second direction crossing with the first direction, and connecting same numbered first electrodes of the electrode groups, wherein each end of the connection electrodes forms a pad portion; and a second electrode facing to the plurality of the first electrodes with a liquid crystal cell therebetween.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
Referring to attached figures, preferred embodiments of the present disclosure will be described. Like reference numerals designate like elements throughout the detailed description. However, the present disclosure is not restricted by these embodiments but can be applied to various changes or modifications without changing the technical spirit. In the following embodiments, the names of the elements are selected for ease of explanation and may be different from actual names.
In this embodiment, the hologram display panel 10 may have the similar structure as shown in
On the path of the collimated light is going (+Z axis of
The hologram display panel driver 50 includes a gate driver and a data driver. The data driver receives the hologram data DATA from the controller 80 and then converts the hologram data DATA to the positive/negative analogue data voltages using the positive/negative gamma compensation voltage supplied from the gamma voltage generator (not shown). The data driver supplies the positive/negative analogue data voltages to the data lines of the hologram display panel 10. The gate driver supplies the gate pulse (or ‘scan pulse’) synchronized with the data voltage to the gate lines of the hologram display panel 10 sequentially, by the controlling signal from the controller 80.
The deflector driver 60 supplies the driving voltages for controlling the deflector 30 to the deflector 30. The driving voltages can decide the inclined amount of the prism pattern formed at the deflector 30 so that the hologram images can be radiated to a proper position of the user/observer. The driving voltages may be groups of voltages which are linearly increased or decreased for linearly controlling the alignment of the liquid crystal molecules disposed in the liquid crystal cell.
The controller 80 may control the hologram display panel driver 50 for driving the hologram display panel 10. The controller 80 supplies the gate control signal GCS to the gate driver and it supplies the data control signal DCS and the hologram data DATA to the data driver. The gate control signal GCS may include a gate start pulse, a gate shift clock, a gate output enable and so on. The data control signal DCS may include a source start pulse, a source sampling clock, a source output enable, a polarity signal and so on.
The detecting camera 90 takes the pictures of the observer and sends them to the controller 80. The controller 80 analyses the images of the pictures and calculates the position of the observer. The controller 80 compares the detected position of the observer with the reference position to decide the relative position of the observer from the reference position. According to this relative position of the observer, the controller 80 controls the deflector driver 60 to form the prism pattern having proper inclined angle at the deflector 30. For the case that the observer moves to a horizontal direction from the reference position, the deflector driver 60 makes the deflector 30 form a prism pattern for refracting the light to the horizontal direction (along the X axis).
According to the X value of the observer's position, the deflector 30 may changes the refraction angle of the light of the hologram images. For example, when the observer's position has a positive value on the X axis, the deflector 30 may form the first prism pattern to refract the light of hologram images to the +θ direction. On the other hand, when the observer's position has a negative value on the X axis, the deflector 30 may form the second prism pattern to refract the light of hologram images to the −θ direction. In addition, when the difference between the observer's position and the reference position is not larger than the predetermined threshold value, the controller 80 decides that the observer is stay on the reference position. In that case, the deflector 30 does not form any prism pattern so that the light of the holography image is passing through the deflector 30 as it is.
The deflector driver 60 may include a look-up-table (or ‘LUT’) having the first driving voltage group for transmitting the light as is, the second driving voltage group for refracting the light to +θ direction, and the third driving voltage group for refracting the light to −θ direction. In this case, responding to the controlling signal from the controller 80, the deflector driver 60 may output any selected one of the first to third driving voltage groups. Here, the look-up-table may include a plurality of the second driving voltage groups and a plurality of the third driving voltage groups in order that the prism pattern may have various inclined angles for corresponding to the various positions of the observer
Hereinafter, referring to
As shown in figures, in the ECB mode, the prism pattern 1PP and 2PP can be represented by controlling the alignment direction of the liquid crystal molecules. In the ECB mode, the liquid crystal molecules can have any direction angle between the horizontal state (X axis on the
By controlling the aligned directions of the liquid crystal molecules included in one pitch 1P of the prism pattern 1PP and 2PP as to be progressively changed from vertical state to the horizontal state along to the +X axis, it is possible to make a prism pattern having the inclined angle of +θ, as shown in
At first, in the case the prism pattern has the inclined angle of +θ, as shown in
Further, in the case the prism pattern has the inclined angle of −θ, as shown in
When the observer is on the reference position, the liquid crystal molecules are in the initial aligned condition. That is, no electric power is supplied to the first electrodes. In the ECB mode, when no electric field is supplied to the liquid crystal cell, all liquid crystal molecules are aligned in the initial alignment direction, horizontal direction. In that case, the refraction ratios of the liquid crystal cells have the same value, ne. Therefore, the horizontally polarized light from the hologram display panel 10 would transmit the deflector 30 without any refraction.
In the deflector 30 as mentioned above, the first electrodes 33 supplied with the driving voltages should be disposed having 2 micrometer (μm) gap at most. Forming the first electrodes 33 having the fine pitch like this, the neighboring first electrodes 33 may be shorted each other, or any first electrode 33 may be broken (disconnected).
Considering these problems, in the present disclosure, the first electrodes may be formed as shown in
Referring to
The deflector (light path deflecting panel) 30 can be divided into two areas; the one is display area AA and the other is non-display area NA. One end of one first electrode 33 is connected to one end of other first electrode 33 by the connection electrode 331 in the non-display area NA. In this embodiment, the connection electrode 331 includes the first connection electrode 331a to the fifth connection electrode 331e.
The first connection electrode 331a is running across the panel along the X axis crossing the first electrodes 33. One end of the first connection electrode 331a is extended to one end of the panel to form a pad portion PAD. The first connection electrode 331a is connected to {circle around (a)} electrode of each group via the first node N1.
The second connection electrode 331b is disposed as being parallel and neighbored with the first connection electrode 331a. One end of the second connection electrode 331b is extended to the one end of the panel to form the pad portion PAD. The second connection electrode 331b is connected to {circle around (b)} electrode of each group via the second node N2.
The third connection electrode 331c is disposed as being parallel and neighbored with the second connection electrode 331b. One end of the third connection electrode 331c is extended to the one end of the panel to form the pad portion PAD. The third connection electrode 331c is connected to {circle around (c)} electrode of each group via the third node N3.
The fourth connection electrode 331d is disposed as being parallel and neighbored with the third connection electrode 331c. One end of the fourth connection electrode 331d is extended to the one end of the panel to form the pad portion PAD. The fourth connection electrode 331d is connected to {circle around (d)} electrode of each group via the fourth node N4.
The fifth connection electrode 331e is disposed as being parallel and neighbored with the fourth connection electrode 331d. One end of the fifth connection electrode 331e is extended to the one end of the panel to form the pad portion PAD. The fifth connection electrode 331e is connected to {circle around (e)} electrode of each group via the fifth node N5.
In addition, all {circle around (a)} electrodes of each group are connected via the first connection line 333a. All {circle around (b)} electrodes of each group are connected via the second connection line 333b. All {circle around (c)} electrodes of each group are connected via the third connection line 333c. All {circle around (d)} electrodes of each group are connected via the fourth connection line 333d. All {circle around (e)} electrodes of each group are connected via the fifth connection line 333e.
At the non-display area NA, one end of the nth first electrode 33 is connected to the same nth first electrodes 33 of other group by the connection electrode 331. The connection electrodes 331 form the pad portion PAD at one end side of the substrate. Further, the other end of the nth first electrode 331 is connected to the same nth first electrode 33 of other group by the connection line 333.
To the pad portion PAD, a conductive flexible film, such as COF (Chip On Film) on which IC package is mounted, may be attached to connect the connection electrode 331 to the driver IC. The driving voltages may be supplied to the {circle around (a)} electrode, the {circle around (b)} electrode, the {circle around (c)} electrode, the {circle around (d)} electrode and the {circle around (e)} electrode included in each group G1, G2, . . . Gn via the IC package and the connection electrode 331. As the first connection electrode 331a is connected to all {circle around (a)} electrodes of all groups via the first node N1, V1 voltage received from the IC package can be supplied to all {circle around (a)} electrodes.
Further, as all {circle around (a)} electrodes are also connected via the first connection line 333a, even though if any one {circle around (a)} electrode is not connected to the connection electrode 331a, that is if any first node N1 is failed, the voltage V1 can be supplied to the disconnected {circle around (a)} electrode via the first connection line 333a.
As the same nth first electrodes of all group are connected each other, the number of the IC package can be minimized. If not, each first electrode should have its own channel for IC package, so that the IC package's number may be equal to or larger than the integer number of (the number of the first electrode)/(number of channel per IC package). However, according to the present disclosure, only one IC package having 5 channels would be enough.
In the above embodiment, each group of the first electrodes is driven with the same driving voltages. However, each group may be driven by different driving voltages. In this case, other IC packages may be required for supplying different driving voltages and the groups using the same driving voltages may be connected same IC package.
In addition, the first electrodes 33 disposed in the display area AA may be made of a transparent conductive electrode. The connection electrode 331 and the connection line 333 disposed in the non-display area NA may be made of metal electrode. In that case, the transparent conductive electrode and the metal electrode are formed at different layers, respectively having an insulating layer therebetween. Then, they can be electrically connected each other via contact hole formed at the non-display area. This structure will be explained referring to
The first substrate 31 facing with the hologram display panel 10 may be med of a transparent plastic substrate or a glass substrate. The first substrate 31 is disposed at the light incident side of the deflector 30. On the first substrate 31, a plurality of the first electrodes 33 are formed. The first electrode 33 may be formed by depositing a transparent conductive material such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO) and patterning it through the photolithography method. The first electrodes 33 may be line pattern running along to one direction of the first substrate 31. The neighboring first electrodes 33 are apart with predetermined distance from each other and disposed in parallel.
In
The second substrate 32 may be made of a transparent plastic substrate or a glass substrate, like the first substrate 31. The second substrate 32 is disposed at the light radiated side of the deflector 30.
On the second substrate 32, a second electrode 34 is formed. Unlike the first electrodes 33, the second electrode 34 is formed as one body by depositing a conductive material on the whole surface of the second substrate 32. The second electrode 34 can be made of the transparent conductive materials including indium-tin-oxide (ITO) or indium-zinc-oxide (IZO), for transmitting the light. On the second electrode 34, a third insulating layer 36 is deposited to protect the second electrode 34. The third insulating layer 36 may include the silicon nitride SiNx or the silicon oxide SiOx.
Between the first substrate 31 and the second substrate 32, a plurality of column spacers CS are disposed for keeping the cell gap, the joining distance between the first substrate 31 and the second substrate 32, evenly. Over the spacer CS, black matrixes BM is disposed for preventing the light from being reflected by the column spacers CS or being recognized by any observer.
The transparent first electrode 33 is formed on the first substrate 31. Over the transparent first substrate 33, the first insulating layer 35a is deposited. Some portions of the transparent first electrode 33 are exposed through the first contact hole CH. The metal connection electrode 331 or the metal connection line 333 is formed over the exposed first electrode 33 so that the first electrode 33 can be connected to the connection electrode 331 or to the connection line 333. Over the first insulating layer 35a, the second insulating layer 35b may be further deposited.
The liquid crystal cell LC disposed between the first substrate 31 and the second substrate 32 may include the ECB (Electrically Controlled Birefringence) mode liquid crystal material.
Referring to
At the step S102, the detecting camera 90 takes pictures of the observer and sends the picture images to the controller 80. The controller 80 analyzes the picture images to calculate the coordination of the observer's position. The controller 80 compares the calculated coordination of the observer's position with the coordination of the reference position to decide the relative coordination of the observer's position. If the observer's position is shifted to +θ from the reference position, the controller 80 sends the second driving voltage corresponding to the observer's position to the light path deflecting panel (or ‘deflector’) 30. The deflector 30 forms a prism pattern to refract the light from the hologram display panel 10 to the correct position of the observer.
According to the moved position of the observer, that is, it is shifted to +θ or −θ, the deflector 30 forms different prism pattern to refract the light properly. For example, when the observer moves to +θ direction, the deflector 30 may form the prism pattern as shown in
In other hand, at the step 107, when the movement of the observer's position by detecting and calculating the position of the observer is less than a predetermined threshold value, it is decided as the observer is not moved. The deflector 30 may not form any prism pattern so that the light from the hologram display panel 10 may pass the deflector 30 as is.
As mentioned above, in one embodiment of the present disclosure, the light path deflecting panel (or ‘deflector’) 30 may be disposed between the hologram display panel 10 and the observer. The deflector 30 can form various prism patterns corresponding to the left or right shifting amount of the observer's position. As a result, the deflector 30 can control the direction of the light for representing the hologram images. According to the present disclosure, as the hologram images can follow the varied position of the observer, it is possible to enjoy the hologram images, even though the observer moves out of view angle of the hologram image system having the narrow view angle.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2012-0153826 | Dec 2012 | KR | national |
