KR20050022955A - A multiple-view directional display - Google Patents

Abstract

PURPOSE: A multiple view directional display is provided to increase the angular distance between two viewing windows for right-eye screen and left-eye screen, thereby effectively display a stereoscopic image, by using an image display layer and a parallax optic sandwiched between two substrates. CONSTITUTION: A multiple view directional display(58) comprises an image display part and a parallax optic(13). The image display part includes the first substrate, the second substrate(6), and an image display layer(8) sandwiched between the first and the second substrates. Herein, the parallax optic is disposed within the image display part. The parallax optic is capable of being disposed between the first substrate and the second substrate, within one of the first substrate and the second substrate. The first substrate includes a base substrate(19), and a light transmitting layer(20) over the base substrate, wherein the parallax optic is capable of being disposed between the base substrate and the light transmitting layer.

Description

Multi-screen directional display {A MULTIPLE-VIEW DIRECTIONAL DISPLAY}

The present invention relates to a multi-screen directional display representing two or more images so that each picture can be viewed in a different direction. Thus, two observers looking at the display from different directions see different images. Such a display can be used, for example, as an autostereoscopic display device or a dual screen display device. The invention also relates to a method for manufacturing parallax barrier substrates and multi-screen directional displays.

For many years, conventional display devices have been designed for simultaneous viewing by multiple users. The display characteristics of the display device are made so that users can see equally good picture quality from different angles with respect to the display. This is useful in fields where multiple users need the same information, such as a display showing departure information at an airport or railway station. However, there are many areas where it may be desirable for individual users to be able to see different information from the same display. For example, in a car the driver may want to view satellite navigation data while the passenger may want to watch a movie. This conflicting need can be met by providing two separate display devices, but this takes up additional space and increases cost. Also, if two separate displays are used in this example, the driver may be distracted by turning his head to look at the passenger display. As another example, in a computer game for two or more players, each player may wish to view the game on their own screen. Currently, for this purpose, each player has their own screen on a dedicated screen by viewing the game on a separate display screen. However, providing separate display screens for each player takes up a lot of space and adds cost, and is not practical for portable games.

In order to solve these problems, a multi-screen directional display has been developed. One field of multi-screen directional displays is a "dual-view display," which can display two or more different images at the same time, and each image can only be seen in a particular direction, thus providing a display device in one direction. The observer looking at the viewer and the viewer looking at the display device in another direction sees a different image. A display that can show different images to two or more users significantly reduces space and cost compared to using two or more separate displays.

Although examples of the applicable fields of the multi-screen directional display device have been described above, there are many other fields. For example, it may be used in an airplane that provides each passenger with his own in-flight entertainment program. Recently each passenger is typically provided with a personal display device in the backrest of the front seat. Multi-screen directional displays offer significant savings in cost, space, and weight by providing a display for two or more passengers while allowing them to choose the movie of their choice.

Another advantage of a multi-screen directional display is that users can be prevented from seeing different people's screens. This is desirable in areas where security is required, such as banking or commerce using ATMs, and in the field of computer games described above.

Multi-screen directional displays can also be applied to the manufacture of three-dimensional displays. In a normal visual state, both eyes of the person accept the world's sights in different perspectives due to different positions in the head. The brain then uses these two perspectives to evaluate the distance to various objects in a scene. To make a display that effectively represents a three-dimensional image, one must reproduce this condition and provide a so-called "stereoscopic pair" of images corresponding to each eye of the observer.

Three-dimensional displays are classified into two types according to the method used to provide different screens for both eyes. Stereoscopic displays typically display two images of stereoscopic image pairs over a wide viewing area. Each picture is encoded, for example, by color, polarization state, or display time. The user must wear glasses of a filter system that separates the screens and allows each eye to see only the screen corresponding to that eye.

The autostereoscopic display displays a right-eye screen and a left-eye screen in different directions, so that each screen is visible only in a limited space area. The area of space in which an image is visible throughout the display active area is called a "viewing window." When the observer is positioned so that the left eye is in the viewing window for the left eye screen of the stereoscopic pair and the right eye is in the viewing window for the right eye image of the stereoscopic pair, the observer's eyes show the correct scene and the 3D image is displayed. It is recognized. Autostereoscopic displays do not require a viewing aid to be worn by an observer.

Autostereoscopic displays are similar in principle to dual screen displays. However, the two images appearing on the autostereoscopic display are left eye images and right eye images of the stereoscopic image pairs and are not independent of each other. In addition, two images are displayed such that each image is visible to each observer's eye while two images are displayed to one observer.

In flat panel autostereoscopic displays, the structure of the see-through window typically consists of a picture element (or pixel) structure of the picture display unit of the autostereoscopic display and of an optical element, commonly referred to as a parallax optic. Due to the combination. An example of parallax optics is a parallax barrier, which is a screen with transmission zones in the form of predominantly slits separated by opaque zones. This screen can be installed on the front or back of a spatial light modulator (SLM) with a two-dimensional array of picture elements to create an autostereoscopic display.

1 is a plan view of a conventional multi-screen directional device in the case of an autostereoscopic display. The directional display 1 consists of a spatial light modulator (SLM) 4 and a parallax barrier 5 constituting an image display device. The SLM of FIG. 1 is in the form of an active matrix thin film transistor (TFT) substrate 6, an opposing substrate 7, and a liquid crystal layer 8 disposed between the substrate and the opposing substrate. The SLM has an addressing electrode (not shown) that defines a plurality of independently-addressable picture elements, and an alignment layer (not shown) for aligning the liquid crystal layer. Perspective angle increasing film 9 and linear polarizer 10 are provided on the outer surface of each substrate 6 and 7. Illumination 11 is supplied from a backlight (not shown).

The parallax barrier 5 comprises a substrate 12 having a parallax barrier opening array 13 formed on its surface adjacent to the SLM 4. The opening array includes a transparent opening 15 extending vertically (ie, extending into the ground in FIG. 1) separated by the opaque portion 14. An anti-reflection (AR) coating 16 is formed on the opposite surface of the parallax barrier substrate 12 (formed on the outer surface of the display 1).

The pixels of the SLM 4 are arranged in columns and rows extending into the ground of FIG. The pixel pitch (distance from the center of one pixel to the center of an adjacent pixel) in the row or in the horizontal direction is p. The width of the vertically extending transmissive slit 15 of the aperture array 13 is 2w, and the horizontal pitch of the transmissive slit 15 is b. The face of the barrier opening array 13 is spaced apart from the face of the liquid crystal layer 8 by a distance s.

In use, the display device 1 forms a left eye image and a right eye image, and an observer whose head is positioned so that his left and right eyes coincide with each of the left eye sight window 2 and the right eye sight window 3 respectively. You will see a three-dimensional image. Left and right eye viewing windows 2 and 3 are formed on the window surface 17 at a predetermined viewing distance from the display. The window surface is spaced apart from the plane of the opening array 13 by a distance γ ₀ . The windows 2, 3 are continuous within the window surface and have a pitch corresponding to the average distance between the human eyes. The half angle with respect to the center of each window 2, 3 from the normal axis to the display normal is α _s .

The pitch of the slits 15 in the parallax barrier 5 is chosen to be close to an integer multiple of the pixel pitch of the SLM 4 so that the group of rows of pixels is associated with a particular slit of the parallax barrier. FIG. 1 shows a display device in which two columns of pixels of the SLM 4 are associated with each transmissive slit 15 of the parallax barrier.

Figure 2 shows the angular zone of light generated from the SLM 4 and the parallax barrier 5, where the parallax barrier has a pitch of an exact integer multiple of the pixel column pitch. In this case, the angular regions coming from different places across the display panel surface are mixed, and image 1 or image 2 (where 'image 1' and 'image 2' are the two images displayed by the SLM 4). The pure area of the screen does not exist. In order to address this, the pitch of the parallax barrier is preferably slightly reduced to be slightly smaller than an integer multiple of the pixel column pitch. As a result, the angular area is concentrated in the front of the display in a pre-defined plane ("window face"). This effect is shown in the accompanying Figure 3 showing the image area generated by the SLM 4 and the modified parallax barrier 5 '. When created in this manner, the plan view of the see-through area is approximately kite-shaped.

4 is a plan view of another conventional multi-screen directional display device 1 '. Mostly correspond to the display device 1 of FIG. 1 except that the parallax barrier 5 is located on the backside of the SLM 4 and is between the backlight and the SLM 4. This device may have the advantage that parallax barriers are less visible to the viewer, and pixels on the display appear closer to the front of the device. Also, although each of FIGS. 1 and 4 shows a transmissive display device illuminated by a backlight, a reflective device using ambient light (in the bright state) is known. In the case of a transflective device, the rear parallax barrier of Figure 4 does not absorb ambient light. This is an advantage if the display has a 2D mode using reflected light.

In the display device of Figs. 1 and 4, the parallax barrier is used as the parallax optic. Several types of parallax optics are known. For example, a lenticular lens array can be used to send mixed images in different directions to form two or more images that are each viewed in different directions or to form a stereoscopic pair.

Holographic methods of image splitting are known, but in practice such methods suffer from the problem of viewing angles, pseudoscopic areas and lack of ease of image control.

Another type of parallax optic is a micropolariser display, which uses a patterned high precision micropolarizer element and a polarized directional light source aligned with the pixels of the SLM. Such displays offer the possibility of high window picture quality, compact devices, and the ability to switch between 2D and 3D display modes. The main requirement when using micropolarizer displays with parallax optics is that parallax problems should be avoided when micropolarizer elements are mixed into the SLM.

If a color display is desired, each pixel of the SLM 4 generally has a filter associated with one of the three primary colors. By controlling a group of three pixels each with a different color filter, many visible colors can be produced. In autostereoscopic displays each stereoscopic image channel must include sufficient color filters for balanced color output. Since many SLMs have color filters arranged in vertical rows for ease of manufacture, all pixels within a given column have the same color filters associated with them. If the parallax optics are arranged on such an SLM with a lenslet of parallax optics or three pixel rows associated with each slit, each perspective region will show only one color of pixel. To avoid this situation, pay attention to the color filter layout. A more detailed description of suitable color filter layouts is described in EP-A-0 752 610.

The function of the parallax optics in the directional display device as shown in Figs. 1 and 4 is to limit the light transmitted through the pixels of the SLM 4 to a predetermined output angle. This limitation defines the viewing angle of each pixel column on the backside of certain elements of the parallax optic (eg, such as transmission slits). The angular range of the perspective of each pixel includes the pixel pitch (p), the spacing (s) between the plane of the pixel and the plane of the parallax optics, and the material between the plane of the pixel and the plane of the parallax optics (the substrate 7 ) Is determined by the refractive index n. H. IEICE Trans by H. Yamamoto and others. Electron, vol. E83-C, No. 10, p1632 (2000), "Optimum parameters and viewing areas of stereoscopic full-colour LED displays using parallax barrier", show images on automatic stereoscopic displays. It is disclosed that the angular spacing between them depends on the distance between the display pixel and the parallax barrier.

The half angle α of Fig. 1 or Fig. 4 is given by the following equation.

[Equation 1]

One problem with many existing multiscreen directional displays is that the angular spacing between two pictures is too small. In principle, the angle 2α between the see-through windows can be increased by increasing the pixel pitch p, decreasing the spacing s between the pixel and parallax optics, or increasing the refractive index n of the substrate. .

Confirmation of the prior art

Co-pending UK patent application 0315171.9 discloses a novel pixel configuration for use with standard parallax barriers that provide greater angular spacing between viewing windows of a multi-screen directional display. However, it may be desirable to be able to use standard pixel configurations in multi-screen directional displays.

Co-pending UK patent applications 0306516.6 and 0315170.1 propose to increase the angular spacing between viewing windows of a multi-screen directional display by increasing the effective pitch of the pixels.

JP-A-7 28 015 proposes to increase the pixel pitch and increase the angular spacing between the viewing windows of a multi-screen directional display by rotating the pixel configuration such that the color subpixels are arranged horizontally rather than vertically. This increases the pixel width by three times and the perspective angle by approximately three times. However, this has the disadvantage that it increases the visibility of the parallax barrier for the observer because the pitch of the parallax barrier must increase as the pixel pitch increases. The fabrication and operation of such non-standard panels may not be cost effective. It may also be necessary to increase the perspective angle to be three times or more the standard configuration, in which case simply rotating the pixels will not be sufficient. This problem often occurs in high resolution panels.

However, in general, the pixel pitch cannot be changed because it is limited by the required resolution specification of the display device.

Changing the refractive index of a substrate usually made of glass is not always quite practical or cost effective.

Another attempt to increase the angular spacing between viewing windows of a multi-screen directional display device has been to reduce the spacing between the face of the SLM's pixels and the parallax optics. However, this is difficult as will be described later with respect to Fig. 5, which is a schematic block diagram of the display device 1 of Fig. 1 using an LCD as the SLM 4.

The LCD panel forming the SLM 4 is made of two glass substrates. The substrate 6 is known as a "TFT substrate" because it supports the TFT switching element for addressing the pixels of the SLM. Also in general, the substrate supports other layers, for example to align the liquid crystal layer 8 and to allow electrical switching of the liquid crystal layer. On another substrate 7 (corresponding to the opposing substrate of FIG. 1), for example, a color filter 18 is formed together with another layer for aligning the liquid crystal layer. Thus, the counter substrate 7 is generally known as a "color filter substrate" or CF substrate. The LCD panel is formed by arranging a color filter substrate opposite the TFT substrate and inserting the liquid crystal layer 8 between the two substrates. In conventional directional displays, parallax optics are attached to the completed LCD panel as shown in FIG. The distance between the LCD pixel and the parallax optic is mainly determined by the thickness of the CF substrate of the LCD. Reducing the thickness of the CF substrate reduces the distance between the LCD pixels and the parallax optics, but this weakens the substrate. The practical minimum for LCD substrate thickness is about 0.5 mm, but the pixel-to-parallax optic spacing can still be too large in most cases if parallax optics are attached to a substrate of this thickness.

Japanese Patent No. 9-50 019 discloses a method of reducing the viewing distance by increasing the angular spacing between the viewing windows of the multi-screen directional display device. This patent proposes to reduce the thickness between the LCD and the barrier. This is accomplished by constructing a stereoscopic LCD panel in order of LCD panel, parallax barrier, and polarizer. The original sequence was LCD panel, polarizer, parallax barrier, as shown in FIG. This reduces the spacing between the pixel plane and the parallax barrier by the thickness of the polarizer, but the angular spacing between the viewing windows of the multi-screen directional display device is only limited in increasing.

GB 2 278 222 discloses a spatial light modulator with a microlens array disposed near a liquid crystal layer to prevent secondary image formation from occurring at high angles of incidence.

GB 2 296 099 discloses a spatial light modulator with elements such as a half wave plate 32 and a polarizer disposed between two substrates of the spatial light modulator. This is to avoid having to use a high isotropic substrate, which makes it possible to use inexpensive and light plastic substrates. If the polarizer is disposed outside of the spatial light modulator, the substrate of the spatial light modulator must have high isotropy so that the substrate prevents a change in the polarization direction of the light passing through the substrate.

US-A-5 831 765 discloses a directional display having a liquid crystal panel and a parallax barrier. The parallax barrier is not placed inside the liquid crystal panel, the parallax barrier is outside the liquid crystal panel, and is separated from the liquid crystal layer by the substrate and the diffuser of the liquid crystal panel.

US-A-4 404 471 discloses a lenticular film for use with X-rays. Mercury, lead or tungsten powder, or other flowable X-ray absorbers enter the recesses in the X-ray penetrating materials.

The present invention provides a multi-screen directional display having an image display element and parallax optics, the image display element comprising a first substrate, a second substrate and an image display layer interposed between these first and second substrates. And the parallax optics are disposed inside the image display element.

Placing the parallax optics within the image display element places the parallax optics close to the image display layer, thereby reducing the spacing s of equation (1) and increasing the angular spacing between the two viewing windows produced by the display device. Since there is no need to reduce the thickness of one of the substrates of the image display element, the structural strength of the image display element is not affected.

The display of the present invention is adapted to use light in the visible region of the spectrum to display an image that is within the visible region of the spectrum and is directly visible to the viewer.

The parallax optic may be disposed between the first substrate and the second substrate. This is a convenient way to position parallax optics close to the image display layer.

Alternatively, the parallax optic may be disposed on either the first substrate or the second substrate. This is another way for the parallax optics to be located close to the image display layer without reducing the thickness of the substrate of the image display apparatus.

Alternatively, the parallax optics may be disposed within the thickness of the first substrate.

The parallax optics comprise a plurality of parallax elements, each parallax element disposed in each recess in the major surface of the first substrate.

The first substrate may include a base substrate and a light transmissive layer disposed on the base substrate, and the parallax optic may be disposed between the light transmissive layer and the base substrate.

The first substrate may include a base substrate, a light transmitting layer disposed on the base substrate, and a plurality of recesses formed in the light transmitting layer, the parallax optics may include a plurality of parallax elements, each parallax element It is arranged in each recess in the light transmitting layer.

Each parallax element may be disposed on the bottom surface of each recess.

The cross section of the recess parallel to the surface of the substrate may decrease with depth.

Each parallax element may substantially fill each recess.

The array of color filters or the array of switching elements can be disposed above the main substrate of the first substrate.

The display may also include a light transmitting layer disposed between the parallax optics and the color filter array or the array of switching elements.

The display may also include other parallax optics disposed between the parallax optics and the array of color filters or the array of switching elements.

The array of color filters or the array of switching elements can be disposed on the second major surface of the first substrate.

The light transmissive layer may be disposed between the parallax optic and the image display layer.

One of the array of parallax optics and color filter and the array of switching elements can be disposed above the major surface of the base substrate, the base substrate being included in the first or second substrate.

The parallax optics can be arranged on the major surface of the base substrate, and the color filter array of the switching elements is disposed above the parallax optics.

The array of color filters or switching elements may be disposed on the first major surface of the base substrate, and the parallax optics may be disposed over the array of color filters or the switching elements.

The light transmissive array can be arranged between the parallax optic and color filter array or the array of switching elements.

The display may further comprise parallax optics and other parallax optics disposed between the array of color filters or the array of switching elements.

The parallax optics may comprise a number of parallax elements, each parallax element disposed in each recess in the major surface of the first or second substrate.

 The second light transmitting layer may be disposed on the major surface of the base substrate between the base substrate and the first light transmitting layer, a plurality of recesses may be formed in the second light transmitting layer, and the parallax optics may include a plurality of parallax elements Wherein each parallax element is disposed in each recess in the second light transmitting layer.

One of the color filter array or the array of switching elements can be disposed on the first major surface of the base substrate, the parallax optics can be disposed in or on the second major surface of the base substrate, and the base substrate is the first or second one. It is included in the substrate.

The parallax optics may comprise a plurality of parallax elements, each parallax element disposed in each recess in the second major surface of the base substrate.

Each parallax element may be disposed on the bottom surface of each recess.

The cross section of the recess parallel to the surface of the substrate may decrease with depth.

Each parallax element may substantially fill each recess.

The light transmitting layer may be a transparent resin layer, a laminated plastic layer, or a glass layer.

The parallax optic may be a parallax barrier or lenticular lens layer.

Parallax optics can be disabled and addressable.

A second aspect of the present invention is to provide a dual screen display device comprising the multi-screen directional display device defined above.

A third aspect of the invention is to provide an auto-stereoscopic display device comprising the multi-screen directional display device as defined above.

A fourth aspect of the invention includes a light transmissive substrate and a plurality of parallax elements, each parallax element providing a parallax optic disposed in each recess in the surface of the substrate.

The parallax optics of the present invention are for use with light in the visible region of the spectrum.

The cross section of the recess parallel to the surface of the substrate may decrease with depth.

Each parallax element may substantially fill each recess.

A fifth aspect of the present invention provides a method for reducing the thickness of a first substrate of an image display element comprising a first substrate, a second substrate, and an image display layer disposed between the first substrate and the second substrate, and And (b) attaching a third substrate to the first substrate such that the parallax optics are disposed therebetween.

The third substrate may be attached directly to the first substrate or one or more additional components may be interposed between the first substrate and the third substrate.

The parallax optic may be formed on or within the first major surface of the third substrate, and step (b) may include attaching the first major surface of the third substrate to the first substrate of the image display element.

Preferred embodiments of the present invention will be described as illustrative examples with reference to the accompanying drawings.

Like reference numerals refer to like parts throughout.

6A is a schematic plan view of a multi-screen directional display according to a first embodiment of the present invention. The display device 58 includes a first transparent substrate 6 and a second transparent substrate 7, with an image display layer 8 disposed between the first substrate 6 and the second substrate 7. . An array of color filters 18 is provided on the second substrate 7, so that the second substrate will be referred to as a color filter substrate.

The first substrate 9 has pixel electrodes (not shown) for forming an array of pixels in the image display layer 8, and switching elements such as thin film transistors (TFTs) for selectively specifying the pixel electrodes. (Not shown) is also provided. Substrate 6 will be referred to as a "TFT substrate".

In this example, the image display layer 8 is a liquid crystal layer 8. However, the present invention is not limited thereto, and any transmissive image display layer can be used. Moreover, if the display is used in "front barrier mode" with parallax optics disposed between the image display layer and the viewer, the display layer may alternatively be a radioactive display layer such as a plasma display or an organic light emitting device (OLED) or the like.

The display 58 is assembled such that each of the color filters 18 is substantially opposite to each pixel of the image display layer 8. Other components, such as alignment layers, may be disposed on the surface of the substrates 6, 7 adjacent to the image display layer, and counter electrodes or electrodes may be disposed on the CF substrate 7, which components are conventional and no longer described. Will not be. Moreover, display 58 may include additional components, such as polarizers, perspective enhancement films, retroreflective films, and the like, which are also conventional and will not be described further.

The color filter substrate 7 is shown in more detail in Fig. 6A. The color filter substrate 7 may comprise a base substrate 19 made of a light transmitting material such as glass. The parallax barrier opening array 13 may be disposed on one major surface of the base substrate 19. In the embodiment of FIG. 6A, the parallax barrier opening array 13 may be formed by depositing an opaque strip 14 over the surface of the base substrate to form a transmissive slit 15 between the opaque strips.

In the present embodiment, the color filter substrate formed of the light transmissive resin may further include a spacer layer 20 provided in the parallax opening array 13. Thus, the parallax barrier opening array is disposed within the thickness of the substrate 7. Finally, the color filter 18 is disposed on the top surface of the spacer layer 20.

In this embodiment, the parallax barrier opening array 13 is separated from the pixels of the liquid crystal layer 18 by the thickness of the resin spacer layer 20. Since the resin layer 20 can be manufactured very thin, the range of the error (1) is small, and the angle separation of a viewing window can be enlarged. Although the resin layer 20 is shown as a single layer, in practice it may be necessary to form two or more separate resin layers in order to obtain the desired thickness. For example, layer 20 may have a thickness of 50 microns and may comprise polyethylene preephthalate.

FIG. 6D is a schematic plan view of a display 21 according to another embodiment of the present invention, and FIG. 6C shows an opposite substrate of this display. Only differences between this embodiment and the previous embodiment will be described.

In this embodiment, the parallax barrier opening array 13 and the color filter 18 are both disposed on the first major surface of the base substrate 19 of the color filter substrate 7 '. The spacer layer 20 of the color filter substrate formed again from the resin is disposed over the parallax barrier opening array 13 and the array of color filters. Again, the parallax barrier opening array 13 is separated from the pixels in the liquid crystal layer 8 by the thickness of the resin layer 20, which can be made small. Having the parallax barrier and the color filter in the same plane simplifies the manufacture of the display.

The resin layer 20 of Figs. 6A to 6D is easy to produce with a uniform thickness. The layer can be deposited, for example, by spin-coating or printing.

FIG. 7B is a top view of a display 22 according to another embodiment of the present invention, and FIG. 7A shows a color filter substrate of the display 22. Only the differences between this embodiment and the first embodiment will be described.

In the embodiment of FIGS. 7A and 7B, a parallax barrier opening array 13 is deposited over the major surface of the base substrate 19. The color filter substrate 7 further comprises a spacer layer 20 lying on the barrier opening array 13 and the color filter is disposed over the spacer layer 20. Thus, the parallax barrier opening array is disposed within the thickness of the color filter substrate 7. In this embodiment, the spacer layer 20 is a glass spacer layer rather than a resin spacer layer. The glass spacer layer is attached to the parallax barrier and can be etched to the desired thickness.

The use of the glass layer 20 facilitates further processing. For example, when the transmissive layer is a glass layer, fabricating the color filter 18 over the transmissive layer 20 is similar to fabricating a color filter usually on a glass substrate.

FIG. 8B is a schematic plan view of a display 23 according to another embodiment of the present invention, and FIG. 8A shows a CF substrate of this display. The display 23 of this embodiment generally corresponds to the display of FIG. 6B and only the differences in these embodiments will be described. In the display 23, the spacer layer 20 between the parallax barrier opening array and the color filter array is a layer of plastic material. The layer of plastic material is attached to the parallax barrier opening array 13 by a suitable method such as lamination or adhesion. The plastic material 20 may alternatively be printed over the parallax barrier opening array.

Using a laminated plastic layer as the transmission layer 20 may be cheaper than using spin coating techniques for the resin light transmission layer. If resin is used, less material is wasted and the lamination process can be faster.

9B is a schematic top view of a multi-screen directional display 24 according to another embodiment of the present invention, and FIG. 9A shows a CF substrate 25 of the display. The display 24 again includes a TFT substrate 6, a color filter substrate 25, and a liquid crystal layer or other image display layer 8 interposed between the TFT substrate 6 and the color filter substrate 25.

9A shows a color filter substrate 25 of a display. As shown in the figure, a plurality of recesses 26 are formed on the first major surface of the base substrate 19. Base substrate 19 may be formed of any suitable light transmitting material, such as, for example, glass, plastic, or glass reinforced plastic. Recess 26 may be formed by any suitable process, such as, for example, an etching or cutting process. The recess 26 takes the form of a slot that extends across the entire vertical height of the base substrate 19, ie, into the paper plane of FIG. 9A. The recesses 26 preferably have the same depth and width as each other.

A parallax barrier opening array is formed in the base substrate 19 by depositing an opaque material in each recess 26 to cover at least the bottom surface of each recess. The opaque material forms an opaque strip 14 of the parallax barrier opening array, with light transmissive regions formed between the opaque strips 14. Thus, the opaque strip 14 and the parallax barrier opening array are disposed within the thickness of the substrate 25.

The opaque material forming the opaque region of the parallax barrier opening array can be any suitable opaque material and can be deposited by any suitable method. For example, the opaque resin can be deposited in the recess 26 using a spinning process.

Once the opaque material is deposited, the recess is filled with a light transmissive material to planarize the surface of the base substrate 19. For example, the light transmissive resin can be deposited into the recess 26 using a spinning process.

If the surface of the base substrate 19 is made flat, an array of color filters 18 may be deposited over the base substrate 19 to complete the color filter substrate 25.

In this embodiment, the separation between the parallax barrier opening array and the liquid crystal layer approximately coincides with the depth d of the recess 26. The depth d of the recess can be made small, for example 50 microns, so that a larger angular separation between the viewing windows can be obtained.

Fig. 10B shows a display 27 according to another embodiment of the present invention. The display 27 includes a TFT substrate 6, a color filter substrate 25 ′, or a liquid crystal layer (or other image display layer) 8 disposed between the TFT substrate 6 and the color filter substrate 29. do. This embodiment generally corresponds with the embodiment of Figs. 9A and 9B, and only the differences between the two embodiments will be described.

10A is a schematic plan view of the color filter substrate 25 ′ of the display 27. In this embodiment, the color filter 18 is deposited on the first major surface of the base substrate 19. The recess 26 is formed in the second major surface of the base substrate 19 using, for example, an etching or cutting technique. An opaque material is then deposited in the recess to form the opaque strip 14 of the differential barrier opening array. The opaque strip 14 and the parallax barrier opening array are disposed within the substrate 25 thickness. If necessary, the recess can be filled with a light transmitting material to planarize the second major surface of the base substrate 19. As in the embodiments described above, any suitable material may be deposited with an opaque material and may be deposited by any suitable technique. In one preferred embodiment, the opaque resin is deposited into the recess 26 using spinning techniques.

Compared with the conventional display of Fig. 5, the separation between the parallax barrier and the liquid crystal layer is reduced by a recess thickness of, for example, 50 microns, so that each separation between the viewing windows is increased. Since the thickness of the base substrate is reduced only in the region where the recess is present, the structural strength of the base substrate can be larger than when the entire substrate is manufactured with the reduced thickness.

11B is a schematic top view of a multi-screen directional display 28 according to another embodiment of the present invention. The display is composed of a TFT substrate 6, a color filter substrate 29, a liquid crystal layer 8 or another image display layer disposed between the TFT substrate 6 and the color filter substrate 29.

The color filter substrate 29 is shown in Fig. 11A. As shown, the color filter substrate 29 is generally similar to the color filter substrate 7 of Fig. 6A, except that two parallax barriers 13 and 13 'are provided. The color filter substrate 29 comprises a base substrate 19 made of any suitable light transmitting material such as glass, for example. The first parallax barrier opening array 13 is disposed above the first surface of the base substrate. The parallax barrier opening array can be formed, for example, by depositing a strip 14 of opaque material on the substrate to form the opacity 14 of the parallax barrier opening array 13.

The first light transmitting spacer layer 20 may be deposited on the surface of the substrate 19 on which the parallax barrier opening array is formed. The first spacer layer may be formed of, for example, light transmitting resin, glass, or transparent plastic material as in the embodiments of FIGS. 6A, 7A, and 8A described above.

The second parallax barrier opening array 13 ′ is disposed on the top surface of the first spacer layer 20. This second parallax barrier opening array can be provided by depositing an opaque material over the spacer layer 20 to form the opacity 14 'of the second parallax barrier opening array.

The color filter substrate further includes a second spacer layer 20 'provided over the second parallax barrier opening array. Both parallax barrier opening arrays 13, 13 ′ can be disposed within the substrate 29 thickness. The second spacer layer can be any suitable light transmissive material, such as light transmissive resin, glass layer, glass or light transmissive plastic material.

The color filter 18 is deposited on the top surface of the second spacer layer 20 '.

The two parallax barriers 13, 13 ′ are arranged such that the transmissive region of the second barrier 13 ′ is not disposed directly in front of the transmissive region of the first parallax barrier 13. The two parallax barriers are arranged such that the transmissive regions within the second parallax barrier 13 'are aligned with the opaque regions 14 of the first parallax barrier 13, such that the opaque regions 14' of the second parallax barrier 13 'are aligned. ) Is aligned with the transmission region of the first parallax barrier 13. As a result, light emitted by the backlight in a direction parallel to, close to, or normal to the display surface of the display is blocked by one or the other of the parallax barriers 13, 13 ′. Light exiting the second parallax barrier 13 'as the two parallax barriers are arranged such that the transmissive region within the first parallax barrier 13 is laterally offset relative to the transmissive region within the second parallax barrier 13'. Moves in the inclined direction of the first and second ranges with respect to the normal.

Many backlights provide maximum intensity along the normal axis, which is a problem in multi-screen directional displays because the viewing window is located at a position displaced angularly from the normal axis. In a typical dual screen display, two viewing windows may be ± 40 degrees to the normal. The use of two parallax barriers as in the display of FIG. 11B can provide a "black center window"-that is, an area centered on the normal on the display side of the low intensity display.

This embodiment is not limited to the provision of two parallax barriers on the color filter substrate. In principle, three or more arrays of parallax barrier openings may be provided over the substrate 19, with each pair of adjacent parallax barrier opening arrays separated by respective spacer layers.

In the embodiment of Figure 11A, two spacer layers 20, 20 'need not be formed of the same material. The two spacer layers can be made of different materials. For example, the first spacer layer 20 may be a glass layer while the second spacer layer 20 'may be a light transmitting resin layer.

In another embodiment (not shown), the color filter substrate comprises two arrays of parallax barrier openings, one of which is disposed on each side of the base substrate 19. In this embodiment, a first parallax barrier array is formed on the major surface of the base substrate 19, a filter 18 is provided on the first parallax barrier structure, and a light transmitting sprayer layer is shown in FIG. 6A, FIG. It is interposed between the color filter 18 and the first parallax barrier opening array as in 7a and 8a. A second parallax barrier opening array is formed on the second major surface of the base substrate 19, which is covered by the light transmitting layer such that the two parallax barrier opening arrays are disposed within the thickness of the color filter substrate.

12A and 12B show another embodiment of the present invention. 12B is a schematic top view of a multi-screen directional display 30 according to an embodiment of the present invention. The display apparatus includes a TFT substrate 6, a color filter substrate 31 and a liquid crystal layer 8 or other image display layer disposed between the TFT substrate 6 and the color filter substrate 31.

12A is a schematic plan view of the color filter substrate 31 of the embodiment of the present invention. The color filter substrate 31 comprises a base substrate 19 that can be made of any suitable light transmitting material. The plurality of recesses 26 are formed in one surface of the substrate 19 by any suitable process such as etching or cutting. When viewed from the front of the substrate 31, the recess 26 appears to be a parallel strip running from top to bottom of the base substrate 19.

As shown in Fig. 12A, in this embodiment, the width of the recess parallel to the surface of the substrate 19 is reduced with distance in the substrate. In the embodiment of Figure 12A, the recess 26 has a triangular cross section, but the recess is not limited to a particular cross section.

The parallax barrier opening array 13 is formed by depositing an opaque (or reflective) material into the recess 26 to form the opacity 14 of the parallax barrier opening array. The opaque material preferably fills the recess 26 substantially to planarize the top surface of the base substrate 19. In a preferred embodiment, the opaque material is an opaque resin deposited in the recess 26 by a spinning process, but in principle any opaque material can be used.

The color filter substrate 31 includes a light transmitting spacer layer 20 deposited on the top surface of the base substrate 19. The parallax barrier opening array is disposed within the thickness of the substrate 31. As described above, the light transmitting spacer layer may be a light transmitting resin layer, a glass layer, a light transmitting plastic material layer, or the like. The spacer layer may be attached to the substrate 19 in any suitable manner.

As a result, the color filter 18 is deposited on the top surface of the spacer layer 20 to form the color filter substrate 31.

In this embodiment, the parallax barrier has a three-dimensional profile because the opaque element 14 of the parallax barrier opening array extends into the substrate, for example above a finite depth of 50 microns. The parallax barrier operates in the same manner as a conventional parallax barrier such as the parallax barrier of Fig. 6A. However, due to the three-dimensional structure of the parallax barrier, light incident on the parallax barrier at a large angle perpendicular to the plane of the substrate 19 is blocked, while such light rays are conventional parallax barriers of the type shown in FIG. 6A. Will be transmitted by. This will be beneficial to prevent the auxiliary window.

In the color filter substrate of FIG. 12A, the depth of the recess can be varied across the substrate 19 to change the depth of the opaque portion of the parallax barrier. This means that the cutting angle changes across the display device with respect to the normal of the plane of the substrate where the light is blocked.

Fig. 13A shows the color filter substrate 31 'of the present invention, and Fig. 13B shows the color filter substrate of Fig. 13A included in the display 30'. This embodiment is largely similar to the embodiment of Figs. 12A and 12B, only the differences will be described herein.

In the color filter substrate 31 of FIG. 13A, the recess 26 is not formed in the base substrate 19. Instead, the color filter substrate includes a light transmitting spacer layer 32 provided on the base substrate 19, and the recess 26 is formed in the spacer layer 32. Spacer layer 32 may be any suitable material, such as, for example, light transmitting resin, glass, light transmitting plastic material, and the like. The recess 26 may be formed in the spacer layer 32 by any suitable method such as cutting or etching.

An opaque material is deposited in the recess 26 in the spacer layer 32 to form the opacity 14 of the parallax barrier opening array, as described in connection with FIG. 12A. Finally, the second spacer layer 20 is deposited over the first spacer layer 32, and the color filter 18 is formed on the top surface of the second spacer layer 20. The parallax barrier opening array is disposed within the substrate 31 'thickness.

In the above embodiment, the parallax optics are constituted by a parallax barrier opening array. However, the present invention is not limited to this particular type of parallax optics, and other types of parallax optics may be used.

14A and 14B show another embodiment of the present invention in which the parallax optics are formed by a lenticular lens array.

14B is a schematic plan view of a multi-screen directional display according to an embodiment of the present invention. The display 33 includes a TFT substrate 6, a color filter substrate 34, and a liquid crystal layer or other image display layer 8 disposed between the color filter substrate 34 and the TFT substrate 6.

14A shows the color filter substrate 34 of the display device 33. The color filter substrate 34 includes a light transmitting base substrate 19 having a top surface profiled to form the lenticular lens array 35. Base substrate 19 may be formed in any suitable manner by, for example, molding a light transmitting plastic material using a suitable mold to provide a lenticular lens array 35 on one surface of base substrate 19. have. Alternatively, lens array 35 may be formed by compressing the glass substrate.

The color filter substrate further includes a spacer layer 20 deposited on the lenticular lens array 35. The spacer layer transmits light and is preferably formed of a resin or plastic material such that the bottom surface of the spacer layer can follow the profile of the lenticular lens array 35. The color filter 18 is preferably deposited on the top surface of the flat spacer layer 20. The lens array is disposed within the thickness of the substrate 31.

In this embodiment, the separation between the parallax optics (lens-shaped lens array 35) and the liquid crystal layer 8 is equal to the thickness of the spacer layer 20, which must be thick enough to flatten the lens. The spacer layer 20 can be made thin, and large angular separations can be obtained between the see-through windows.

14C and 14D show another embodiment of the present invention. 14C shows another substrate 34a of the present invention. Substrate 34a includes a first light transmissive substrate 19 having a surface profiled to form first lenticular lens array 35. The substrate 34a further has a second light transmissive substrate 19a having a surface profiled to form the second lenticular lens array 35a. The light transmissive substrates 35, 35a may be formed using any suitable manner, such as one of the methods described with reference to FIG. 14A.

The light transmissive substrate is assembled with surfaces formed by lenticular arrays facing each other, as shown in Fig. 14C. The transparent spacer layer 20 is disposed between the two lenticular lens arrays 35 and 35a, and the layer 20 may be, for example, a transparent resin layer or a transparent adhesive layer. The two lenticular lens arrays 35 and 35a are close to each other and are combined with only one curved surface, such as the lens array of FIG. 14A, to provide higher focus power than the lens array. The lenticular array is disposed within the substrate 34a thickness.

The array of color filters 18 is preferably deposited on the outer surface of the flat substrate 34a.

FIG. 14D shows a display 33a including the substrate 34a of FIG. 14C, an image display layer 8 such as a liquid crystal layer, and a second substrate 6.

15A and 15B show another embodiment of the present invention. This embodiment is largely similar to the embodiment of Figs. 14A and 14B, only the differences will be described.

14A and 14B, the lenticular lens array 35 is formed integrally with the base substrate 19, and is obtained by appropriately profiling an upper surface of the base substrate 19. As shown in FIG. However, in the embodiment of FIGS. 15A and 15B, the lenticular lens array 35 ′ is not integral with the base substrate 19. Instead, the base substrate 19 has a substantially flat top surface, and the lenticular lens array 35 ′ is deposited on the top surface of the base substrate 19. This can be done by any suitable technique. For example, a light transmissive resin or light transmissive plastic material layer may be deposited on the top surface of the base substrate 19, which is patterned to form the lenticular lens array 35 ′.

FIG. 15C shows a CF substrate 34 '' that is different from the substrate 34 'of FIG. 15A where the lenticular lens array 34' 'is "duplex". That is, the lenticular array 35 'is plano-convex, while the lenticular array 35' 'is convexo-convex. Although this arrangement is more difficult to manufacture because the recess must be formed in the substrate 19, the optical performance is improved. For example, a display using substrate 34 '' in Figure 15C has a smaller crosstalk area and wider degrees of freedom of viewer movement.

FIG. 15D shows a modified CF substrate 34 'different from the substrate 34' 'of FIG. 15C in that the lens array 34' '' is spaced apart and separated by a black mask area 35 '' ''. ''). In fact, any embodiment using a lens array such as parallax optics may similarly have individual lenses or lens elements separated by black mask regions that do not transmit visible light.

The f-number of the lenticular lens array is required to be very low, which makes the array difficult to manufacture. By reducing the diameter of each array lens and maintaining the pitch constant (by filling the gap between the lenses having the light absorbing material or the light reflecting material or both), the number of f of the lenses can be increased. This arrangement improves performance, for example providing smaller crosstalk areas and wider degrees of freedom of viewer position.

16A and 16B show another embodiment of the present invention. FIG. 16B is a schematic plan view through the multi-screen directional display 37 of this embodiment, and FIG. 16A is a schematic plan view of the color filter substrate 36. This embodiment is largely similar to the embodiment of Figs. 6A and 6B, only the differences will be described herein.

In the embodiment of Figs. 16A and 16B, the positions of the parallax barrier opening array 13 and the color filter 18 are interchanged with those in the embodiments of Figs. 6A and 6B. That is, the color filter 18 is deposited on the main surface of the light transmitting base substrate 19. The spacer layer 20 is deposited over the color filter 18, and the parallax optics are formed on the top surface of the spacer layer 20. In the embodiment shown in Figs. 16A and 16B, the parallax barrier opening array 13 forms parallax optics, but this embodiment is not limited to this particular type of parallax optics. The spacer layer 20 may be a light transmitting resin layer, a glass layer, a plastic material light transmitting layer, or the like.

In the embodiment of FIGS. 16A and 16B, the parallax barrier array 13 is disposed substantially adjacent to the liquid crystal layer 8. Large angular separation between different viewing windows can be obtained.

17A and 17B show a display 38 according to another embodiment of the present invention. In this embodiment, the parallax optic is constructed by a reactive mesogen parallax barrier. This embodiment generally corresponds with the embodiment of Figs. 6A and 6B, only the differences will be described herein.

The RM barrier in this embodiment is formed by a strip of active messaging material disposed on the top surface of the light transmissive base substrate 19 of the color filter substrate 39. Polarizer 41 is provided on the top surface of base substrate 19 including a strip of RM material. The strip of RM material and the polarizer 41 form an RM parallax barrier 42. Manipulation of the RM parallax barrier is described in detail in EP 0 829 744 A.

Since the color filter substrate 39 further includes a spacer layer 20 deposited on the top surface of the RM parallax barrier 42, the parallax barrier 42 is disposed within the thickness of the substrate 39. The color filter 18 is deposited on the top surface of the spacer layer 20. As in the previous embodiment, the spacer layer 20 may be, for example, a light transmissive resin layer, a glass layer, a light transmissive plastic layer, or the like. The base substrate 19 may be a glass substrate, a plastic substrate, a glass reinforced plastic layer, or the like.

In the multi-screen directional display 38 of this embodiment, the separation between the parallax barrier 42 and the liquid crystal layer 8 is equal to the thickness of the spacer layer 20. The spacer layer can be made thin so that good angular separation between different viewing windows can be achieved.

This embodiment has another advantage that the RM parallax barrier is an active parallax barrier, in order to render the strip of RM material 40 transparent so that the parallax barrier is disabled or “switched off” (not shown) By means). If the parallax barrier 42 is disabled, the display device will act as a conventional two-dimensional or single screen display device. Thus, this embodiment is capable of operating in a two-dimensional display mode or a three-dimensional or multi-directional display screen mode mode, and providing a display that can provide good angular separation between adjacent viewing windows when operating in a three-dimensional or multi-screen display mode. to provide.

Fig. 18B shows a display 38 'according to another embodiment of the present invention, and Fig. 18B is a schematic cross sectional view of the color filter substrate 39' of the display. The display 38 ′ of this embodiment is essentially the same as the embodiment of FIGS. 17A and 17B except that the spacer layer 20 is missing and the color filter 18 is disposed directly on the top surface of the polarizer 42. Matches. All other features of the display 38 ′ of FIG. 18B will not be described further because they correspond to the display 38 of FIG. 17B.

19A and 19B show another embodiment of the present invention. In this embodiment, the color filter substrate 44 of the multi-screen directional display has an active parallax barrier 46. 19B is a schematic plan view of the entire display device 43, and FIG. 19A is a schematic cross-sectional view of the color filter substrate 44. FIG.

The active parallax barrier 46 is formed by a plurality of regions 47 of material whose optical properties are switchably disposed on the surface of the base substrate 19. Region 47 may be in the form of a strip extending into the paper surface of FIG. 19A. The active parallax barrier is formed by the region 47 in combination with another layer 45 disposed over the region 47, which may be a linear polarizer or a transparent spacer layer, depending on the material used for the active strip 47.

In a preferred embodiment, region 47 is a liquid crystal material and layer 45 is a linear polarizer. As is well known, the liquid crystal material can be addressed to rotate or not rotate the polarization plane of linearly polarized light passing therethrough. Preferably, the area 47 of the liquid crystal material can be switched between a state of rotating the polarization plane of linearly polarized light by 90 degrees and a state of not rotating the polarization plane of linearly polarized light. Thus, the region 47 of the liquid crystal material can be transmitted by the linear polarizer 45 where light passing through the region 47 is transmitted (in this case, the region 47 forms a transmissive region) by the linear polarizer 45. May be addressed to be blocked (in this case, area 47 forms an opaque area).

The display 43 needs to be irradiated from the color filter substrate side by a light source emitting polarized light or polarized light from a polarizer disposed in front of the light source. Alternatively, it may be irradiated from the TFT side, in which case an additional polarizer (not shown) must be disposed over the color filter substrate.

If light that does not pass through the area 47 of switchable optical properties (eg, passes through the gap between adjacent active areas) is passed by the polarizer 45, light passing through the area 47 is passed through the polarizer. When blocked by, a parallax barrier is formed, in which case a three-dimensional or multi-screen display mode is obtained.

In principle, it is also possible to determine the transmission direction of the polarizer 45 and the polarization direction of the incident light so that light passing through the gap between the regions 47 of the liquid crystal material is blocked by the polarizer 45. In this case, a parallax barrier is formed when region 47 rotates the polarization plane of incident light so that incident light can pass through polarizer 45. However, if area 47 is switched such that light passing through strip 47 is blocked by polarizer 45, a dark display will result because all light is blocked by polarizer.

The area of the active material 47 is not limited to the liquid crystal material. In principle, any material that can be addressed so that its optical properties can be changed can be used. For example, a polymeric scattering liquid crystal material can be used as the material of the active parallax barrier. As is well known, PDLC consists of particles of liquid crystal material scattered through a polymer matrix. The refractive index of the liquid crystal material can be varied, and PDLC will transmit light if the refractive index of the liquid crystal particles is equal to the refractive index of the polymer matrix. However, if the liquid crystal material is converted such that its refractive index is different from the polymer refractive index, light passing through the PDLC is scattered.

Another suitable material for the active parallax barrier is a dichroic guest-host material.

This embodiment allows the parallax barrier to be turned on or off so that a three dimensional (or multi screen) or two dimensional display mode can be selected. Moreover, it is possible to arrange the active parallax barrier 46 so that the shape of the permeable and opaque zones can be changed. For example, the active parallax barrier 46 can be switched such that the opaque region of the barrier moves from one location to another. This allows the barrier to be effectively switched over the area of the display device and to change the position of the viewing window. Thus, in this embodiment, it is possible to control the position of the viewing window by appropriately addressing the active parallax barrier 46. This embodiment is particularly useful when combined with an observer tracking device that tracks an observer of the display because the position of the viewing window can be controlled based on the position of the observer determined by the observer tracking device.

In this embodiment, the polarizer 45 is included in the liquid crystal display element. Therefore, the polarizer 45 must be able to withstand the harsh processing conditions generated during the manufacture of the liquid crystal panel. Conventional polarizers used on the exterior of liquid crystal displays may not be able to withstand such processing conditions well, and thus cannot be used. This has the potential disadvantage of using a polarizer with a lower contrast ratio than conventional polarizers used outside the liquid crystal panel. In this case, the polarizer 45 may be oriented such that the poor contrast ratio affects the contrast ratio of the parallax barrier or the contrast ratio of the pixels of the liquid crystal layer 8.

If layer 45 is a spacer layer, it can be processed to align the liquid crystal material of region 45, for example, with a particular alignment direction and pre-tilt angle. For example, the spacer layer may be coated with a polyimide layer (not shown) to be exposed to and / or rubbing against ultraviolet light in a conventional photo-alignment process.

In another embodiment, the color filter may be disposed on the TFT substrate 6 or between the active parallax barrier 46 and the substrate 19.

20B shows a display 48 according to another embodiment of the invention, and FIG. 20A shows a color filter substrate 49 of the display. This embodiment is the embodiment of FIGS. 6A-6B, except that in this embodiment the color filter substrate 49 of the multi-screen directional display 48 also includes an active parallax optic 35 ''. Usually corresponds to In this embodiment, the active parallax optic 35 '' is an active lenticular lens array. The lenticular lens array can be switched between a mode that generally has a no lensing effect (and therefore no parallax optics) and a mode that has a lens effect (and thus a parallax optics are formed). The lenticular lens array 35 ″ may be addressed by suitable addressing means (not shown).

For example, the lenticules of the lenticular lens array may be made of a liquid crystal material addressed by an electrode (not shown) disposed on opposite sides of the lenticular. The liquid crystal material is selected such that the refractive index is as close as possible to the refractive index of the base substrate 19 for the voltage slightly applied to the lens array. When an appropriate voltage is applied between the electrodes provided on opposite sides of the lenticules, the refractive index of the liquid crystal material of the lenticules closely matches the refractive index of the spacer layer 20, and the lenticules have no lens effect. However, by changing the applied voltage, the liquid crystal material of the lenticules can be changed such that the refractive index is produced differently from that of the substrate 19. Thus, the lenticules act as lenses, forming elements of parallax optics.

The lenticules 50 of the active lenticular lens are designed with graded refractive power (GRIN), which can be designed with Fresnel lenses.

FIG. 20C shows a substrate 49 different from that shown in FIG. 20A in that the glass substrate 19 is recessed to receive the active lenticular lens array 35 ″. In such a structure, the refractive index of the active array generally matches the refractive index of the substrate 19 in a single screen or non-directional mode of operation. FIG. 20D shows the substrate 49 being biconvex so that the lenses of the active array 35 ″ provide improved performance such as smaller crosstalk areas and greater viewer freedom of movement. In this case, in the single screen mode of operation, the index of refraction of the array 35 ″ generally matches that of the substrate 19 and the spacer 20.

FIG. 21B shows a display 48 'according to another embodiment of the invention, and FIG. 21A shows a color filter substrate 49' of the display 48 '. This embodiment is largely similar to the embodiment of Figs. 20A and 20B, only the differences will be described later.

The multi-screen directional display 48 'of FIG. 21B has a color filter substrate 49' that mounts an active active lens array 35 ''. However, in this embodiment, the switching of the lens array is accomplished in another manner. In this embodiment, the lenticules 50 are made of liquid crystal material. However, the microstructure of the liquid crystal material is fixed and the liquid crystal material is not addressed in the operation of the device.

In this embodiment, the switching of the lens array is achieved by utilizing the fact that the refractive index of the liquid crystal material is generally changed in accordance with the polarization state of the light passing therethrough. The liquid crystal material of the lenticules 50 is selected such that the refractive index of the liquid crystal material is approximately equal to the refractive index of the spacer layer 20 for light in one polarization state. Thus, the liquid crystal material generally does not have a lens effect on the light in this polarization state. However, for other polarization states, in particular for polarization states perpendicular to the first polarization state, the refractive index of the liquid crystal material does not coincide with the refractive index of the layer 20 so that the liquid crystal material has a lens effect for light in the second polarization state. Has

The liquid crystal lenticule 50 is switched on or off by changing the polarization state of the light entering the display 48. This can be achieved by providing a polarization switch 51 that can change the polarization state of light passing through the selected portion of the polarization switch 51, for example by selecting one of two vertical linear polarizations. The polarization switch 51 may be composed of, for example, a liquid crystal cell, followed by a polarizer 51 '.

FIG. 21C shows another substrate 49 'recessed in the glass substrate 19 to accommodate the array 35 ". In this case, one of the refractive indices of the materials of the array 35 '' must generally match the refractive index of the glass substrate 19 to provide single screen mode operation.

Fig. 21D shows another form of the color filter substrate 49 'which is double-sided convex and has a recess such that both the spacer 20 and the glass substrate 19 receive the lens array 35 ". In this case, one of the refractive indices of the materials of the array 35 '' needs to generally match the refractive indices of the glass substrate 19 and the spacer 20 to provide a non-directional or single screen mode of operation.

22 is a schematic cross-sectional view of a multi-screen directional display 52 according to another embodiment of the present invention. This is similar in many respects to the display 58 of FIG. 6B, except that a plurality of prisms 53 are provided on the outer surface of the base substrate 19 of the color filter substrate 7. In Fig. 22, the prism 53 is shown to have a triangular cross section. Prism 53 works with parallax barrier 13 provided inside the display device. In use, the device is illuminated by light provided behind the TFT substrate 6 so that the base substrate 19 of the color filter substrate 7 forms the outer surface of the display device. The prism structure changes the separation angle between the left and right images induced by the parallax barrier.

In the embodiment of Fig. 22, the prism is arranged to reduce the separation angle between the viewing windows of another image.

Although the prism is shown as having a triangular cross section in Fig. 22, the present embodiment is not limited to the prism having a triangular cross section. In principle, any prism structure that reduces the angle of separation between two viewing windows can be used. In addition, when a prism having a triangular cross section is used, the prism need not have an equilateral triangular cross section. In fact, any symmetrical or asymmetrical convergent or divergent element can be used, for example, to suit any application of the display.

The embodiment of Fig. 22 illustrates, for example, that the separation between the left eye image and the right eye image is such that the separation between the left eye window and the right eye window is equal to the distance between the two eyes of the person at the preferred viewing distance of the display. It can be used in an autostereoscopic display device as needed to provide it.

Figure 23 shows a display 52 'according to another embodiment of the present invention. This display 52 ′ generally corresponds to the display of FIG. 22, except that a prism 53 provided on the surface of the base substrate 19 is intended to increase the angular separation between the two viewing windows.

Figure 24 shows a multi-screen display directional display 59 according to another embodiment of the present invention. The display 59 of the present embodiment has the display device 20 of FIG. 6B except that the display further comprises switching means 54 for varying the angle between the two viewing windows provided by the device. Mostly consistent. The switching means 54 can be switched between a state that does not substantially affect the angular separation between the two viewing windows and other states that increase or decrease the angular separation between the two viewing windows. In the present embodiment, the switching means 54 comprises a plurality of light transmitting prisms 53 mounted on the outer surface of the base substrate 19 of the color filter substrate. The active layer 55 is disposed on the prism 53 to planarize the prism. The active layer is held by the transparent plate 56. The prism and the transparent plate may be formed of glass, transparent resin, transparent plastic material, or the like. The active layer 55 may include, for example, a liquid crystal layer. The liquid crystal layer is selected such that when the electric field is applied across the liquid crystal material, the refractive index of the liquid crystal material matches the refractive index of the prism 53. In this state, the prism has virtually no effect on the angular separation between the two viewing windows produced by the device 54.

The switching means 54 further comprise an electrode (not shown) so that an electric field can be applied across the liquid crystal layer 55. By applying a voltage across the electrode and applying an electric field across the liquid crystal layer, it is possible to change the refractive index of the liquid crystal material such that the refractive index of the liquid crystal material is different from that of the prism 53. Thus, light passing through the interface between the prism and the liquid crystal layer is refracted. As a result, each separation between the two viewing windows formed by the display device is changed by the prism 53. This causes the display 59 to switch between, for example, a dual perspective display mode and an autostereoscopic display mode.

The switching means 54 can allow each separation between the two viewing windows to be continuously controlled by continuously changing the applied electric field across the liquid crystal layer. This allows each separation between the two viewing windows to be adjusted to suit the particular use of the display device 54. This embodiment is particularly useful when information about longitudinal separation between the display and the observer is available, for example from the observation vehicle tracking device. In the autostereoscopic display mode, the switching means 54 can control the angular separation between the left and right eye viewing windows so that the lateral separation at the observer remains the same as the separation between the two eyes of the person.

25 illustrates a multi-screen directional display 57 according to another embodiment of the present invention. This display 57 is largely similar to the display 54 of FIG. 24, and only the differences will be described herein.

In the display 57 of Fig. 25, the switching means 54 for changing the angular separation between the two viewing windows formed by the display are arranged on the outer surface of the substrate 19 of the color filter substrate 7 53). The liquid crystal layer 55 is located above the prism 53, but in comparison with the embodiment of Fig. 24, the microstructure of the liquid crystal layer is fixed. Thus, no means for addressing the liquid crystal layer 55 is needed.

The refractive index of the liquid crystal layer 55 depends on the polarization state of the light passing through the liquid crystal layer. The liquid crystal layer is selected such that in one polarization state the refractive index is substantially the same as the refractive index of the prism 53. In this case, the light passing through the prism is virtually refracted.

However, in light of another polarization state, for example, a polarization state perpendicular to the first polarization state, the refractive index of the liquid crystal material 55 is not equal to the refractive index of the prism 53. Thus, in the light of this second polarization state, refraction occurs at the interface between the prism and the liquid crystal layer 55, leading to a change in the angular separation between the two viewing windows formed by the display 57.

The refractive effect of this embodiment can be switched on or off by appropriately selecting the polarization state of light entering or exiting the panel. This can be done by providing a polarization switch 51 and a polarizer 51 'between the light source and the observer. In Fig. 25, the polarization switch 51 and the polarizer 51 'are disposed between the display device and the observer, but they may optionally be provided between the light source and the display device. For example, the polarization switch can be a liquid crystal cell.

24 and 25 can be performed using a prism structure that increases the angular separation between viewing windows as shown in FIG.

26A and 26D illustrate a method of manufacturing the display of the present invention. First, the method takes a conventional image display apparatus 63 having an image display layer 8 (such as a liquid crystal layer) disposed between two substrates 60 and 61, as shown in FIG. 26A. . The image display device 63 includes an image display layer 8 and other elements such as switching elements and electrodes for controlling color filters in the case of a color image display device. These are entirely prior art and are omitted in FIGS. 26A-26D for clarity of explanation.

According to the method of the present embodiment, the thickness of the substrate 60 of the image display apparatus 63 is preferably reduced in the range of 50 to 150 mu m. The thickness of the substrate 60 may be reduced by any suitable method such as, for example, mechanical polishing or chemical etching. Thus, the substrate 60 is deformed into a thin transparent layer 60 'as shown in Fig. 26B. The thickness of the thin transparent layer 60 'is preferably substantially uniform over the area of the layer 60'.

Next, another substrate 62 is attached to the thin transparent layer 60 'such that the parallax optic 13 is disposed between the thin transparent layer 60' and the other substrate. This can be conveniently done by providing parallax optics on the surface of the other substrate and attaching the surface of the other substrate to the thin transparent layer 60 '. For example, the parallax barrier opening array may be printed onto the surface of another substrate 62 as shown in FIG. 26C. Alternatively, a lenticular lens array or RM parallax barrier may be formed in / on the surface of another substrate. The other substrate 62 may be attached to the thin transparent layer 60 'using a suitable transparent adhesive.

The other substrate 62 may be directly attached to the thin transparent layer 60 'as shown in Figure 26D. Alternatively, one or more elements may be interposed between the other substrate 62 and the thin transparent layer 60 'as described with respect to FIG. 28 below.

The resulting display is shown in Figure 26d (transparent adhesive is omitted in Figure 26d for clarity). The parallax optics are separated from the image display layer 8 only by the thin transparent layer 60 'obtained by reducing the thickness of the substrate 60 (and by reducing the thickness of the transparent adhesive). Thus, the parallax optics are placed close to the image display layer 8, and the above-described advantages are obtained. In the method of Figures 26A-26D, the substrate 60 is incorporated into the display device 63 when its thickness is reduced. Another element of the display device 63 provides physical support for the substrate 60 during the thickness reduction process and after the thickness is reduced. Thus, the thickness of the substrate 60 can be reduced by as small as 50 μm without serious risk of substrate breakage. In contrast, if the thickness of the separated substrate is reduced, it is difficult to significantly reduce the thickness to 0.5 mm or less without serious risk of substrate breakage.

The method of FIGS. 26A-26D is used for manufacturing the display 22 shown in FIG. 7B, for example. When comparing FIG. 26D with FIG. 7B, the other substrate 62 of FIG. 26D corresponds to the base substrate 19 of FIG. 7B, and is obtained by reducing the thickness of the substrate 60 of the image display apparatus 63. The thin transparent layer 60 ′ of 26d corresponds to the glass layer 20 between the parallax barrier 13 and the color filter array 18 of FIG. 7B.

The method of FIGS. 26A-26D is used in display fabrication where parallax optics are not a parallax barrier opening array. For example, a lens array or RM parallax barrier may be disposed on the surface of another substrate, allowing for the fabrication of the display shown in FIG. 15B or 17B, for example.

The lens array can be attached to another substrate by providing a transparent adhesive layer over the entire area of the substrate. Alternatively, the lens array may be attached to another substrate, for example by arranging the adhesive only at selected locations around each lens. This provides an air gap between the lens and the substrate to which the adhesive is applied, eliminating the reduction in focus power that can occur when there is a transparent adhesive layer having a refractive index close to that of the lens. If the adhesive is placed only in selected locations, it is possible to use an adhesive that is not transparent.

Figure 27 is a cross-sectional view (from above) of display 64 according to another embodiment of the present invention. The display again includes an image display element 65 and has a parallax optic 66 disposed within the image display element. In the present embodiment, the parallax optic is the prism array 66.

Prism array 66 is formed over base substrate 19 (eg, made of glass), and a flat layer 67 is provided over the prism array. Base substrate 19, prism array 66, and flat layer 67 form substrate 68 of image display element 65. For example, an image display layer 8 of the pixelated liquid crystal layer is disposed between the substrate 68 and the second substrate 6. For example, other elements of the image display element such as the color filter array (in the case of the full color display), the alignment layer, the switching element, and the electrodes are all conventionally included and thus omitted in FIG.

Display 64 includes a backlight 69 that illuminates image display element 65 with collimated or partially collimated light. Light from the backlight is refracted by the prism of the prism array and directed to the left viewing window 2 or the right viewing window 3. When two staggered images are displayed on the pixel 70 of the image display layer 8, a directional display is provided. Using a prism array to guide light into two viewing windows means that a backlight 69 with a relatively low degree of collimation is used. Alternatively, if a lens array is used instead of a prism array, it is necessary to use a backlight having a high degree of collimation.

One way in which the substrate 68 can be fabricated is to place a photoresist layer over the base substrate 19. The refractive index of the photoresist should be as close as possible to the refractive index of the base substrate 19, and the refractive index of the photoresist is preferably equal to or nearly equal to that of the base substrate 19. The prism array 66 is then formed in the photoresist layer using conventional masking, irradiation, and etching steps.

A flat layer 67 is then disposed over the prism array 66. The flattening layer 67 preferably has the minimum thickness necessary to planarize the substrate 68.

Elements such as alignment layers, color filters, and the like may be provided on the substrate 68 using any suitable technique. Substrate 68 may then be assembled with second substrate 6 to form image display element 65.

The refractive index of the flat layer 67 is different from the refractive index of the prism array 66 such that light is refracted at the interface between the prism array 66 and the flat layer 67. While it is usually easier to find a suitable material for a flat layer having a substantially lower refractive index than the prism array, the refractive index of the flat layer may be higher or lower than the refractive index of the prism array (in the direction of refraction, the refractive index of the flat layer is higher than the prism). Depending on whether it is higher or lower than the refractive index of the array).

Embodiments of the present invention have been described with regard to specific forms of parallax optics. However, the present embodiment is not limited to the specific type of parallax optics shown, but can be used with other types of parallax optics.

The present invention allows the substrate on which the parallax optics are mounted to be mounted for use as a substrate of an image display element such as, for example, a liquid crystal display element. This has the advantage that the parallax optics and the alignment of the pixels of the display element are performed during the fabrication of the display element. This allows the alignment to be performed more accurately compared to the conventional case where the outer parallax optics are aligned with the complete liquid crystal display element (as in FIG. 1). In addition, eliminating the step of adhering or otherwise attaching the parallax optics to the complete image display element makes the manufacturing process faster and cheaper.

Figure 28 is a schematic plan sectional view of a multi-screen directional display 76 according to another embodiment of the present invention. The display 76 includes a first transparent substrate 6 and a second transparent substrate 71 having an image display layer 8 disposed therebetween. An array of color filters (not shown) is provided on the second substrate 71, so that the second substrate will be referred to as a color filter substrate.

The first substrate 6 is provided with a pixel electrode (not shown) that forms a pixel array of the image display layer 8, and also not shown (such as a thin film transistor (TFT) for selectively addressing the pixel electrode. Switching electrodes are provided. The substrate 6 will be referred to as a "TFT substrate". In this embodiment, the image display layer 8 is a liquid crystal layer 8. However, the present invention is not limited thereto, and any transparent image display layer may be used.

The display 76 is assembled such that the color filter is substantially respectively opposed to each pixel of the image display layer 8. Other elements, such as an alignment layer, may be disposed on the surface of the substrates 6, 71 adjacent to the image display layer, and the opposite electrode or electrodes may also be disposed on the CF substrate 71. These elements are included in the prior art and will not be described further. In addition, the display 76 may further include elements such as an angle of view enhancement film, an antireflective film, and the like disposed outside the image display element. These elements are also included in the prior art and will not be described any further.

The color filter substrate 71 includes a transparent waveguide 74, a linear polarizer 73 disposed on the waveguide 74, and a transparent layer 72 disposed on the linear polarizer 73. The waveguide 74 not only forms part of the color filter substrate 71 but also forms part of the backlight of the display.

In use, the backlight of the display 76 consists of a waveguide 74 and one or more light sources 75 arranged along the sides of the waveguide. Although only one light source 75 is shown arranged in FIG. 28 along the side surface 74a of the waveguide 74, the present invention is not limited to the specific configuration shown in FIG. 28 and two or more light sources may be used. . By way of example, the display may be provided with two light sources 75 arranged along opposite side surfaces 74a and 74b of the waveguide 74. The light source 65 preferably extends along all or substantially all of each side surface of the waveguide and may be, for example, a fluorescent tube.

Waveguide 74 is attached to polarizer 73 by an adhesive disposed along the edge of polarizer 73. Since the adhesive 81 is disposed only along the edge of the polarizer 73, there is an air gap 82 over most of the region of the polarizer and between the waveguide 74. As is well known, light from light source (s) 75 enters waveguide 74 and is trapped within waveguide 74 by total internal reflection phenomena. Light propagating in the waveguide incident on the front or rear face of the waveguide 74 experiences total internal reflection at the waveguide / air interface and is not emitted from the light guide plate.

Alternatively, waveguide 74 and polarizer 73 may be attached using a low refractive index transparent adhesive, ie, an adhesive having a refractive index lower than that of the waveguide. The low refractive index adhesive may be disposed over the entire area of the polarizer 73 and the internal reflection at the front face of the waveguide 74 is due to the difference between the refractive index of the adhesive and the refractive index of the waveguide.

According to the embodiment of FIG. 28, diffusion dots are provided in selected areas of the front face 74c of the waveguide 74. As shown in FIG. When light propagating in the waveguide is incident on the area 84 of the front face 74c of the waveguide in which the diffusing dot is provided, the light is not specularly reflected but scattered by the diffusing dot as shown in FIG. As a result, some of the light is scattered out of the waveguide towards the image display layer 8.

Light is scattered out of the waveguide 74 only in the region 84 where diffusion dots are present, where light is not emitted from the waveguide 74. Thus, waveguide 74 has a zone that emits light (corresponding to a zone 84 where diffusion dots are present) and a zone that does not primarily emit light. When the area 84 where the diffusion dots are provided has a stripe shape extending into the paper plane of FIG. 28, the area of the waveguide 74 that emits light is, for example, of a parallax barrier such as the parallax barrier 13 of FIG. 6A. The size, shape, and location of the transmissive zones correspond, and the area of the waveguide 74 that does not emit light corresponds to the size, shape, and location of the opaque zone of the parallax barrier. Therefore, the parallax barrier is effectively formed in the front face 74c of the waveguide 74 within the thickness of the color filter substrate 71.

The area of waveguide 74 without diffusion dots may be coated on the absorbing material such that light is not scattered from this area. This reduces the light intensity emitted by the area of the waveguide that is intended to correspond to the opaque zone of the parallax barrier 13 of FIG. 6A.

The diffusion dot may be composed of a diffusion structure, a diffraction structure or a microrefractive structure. The precise structure of these is not important unless light is scattered generally from the area 84 where diffusion dots are provided and light is not scattered generally in areas where diffusion dots are not provided.

Since display 76 of FIG. 28 does not require a parallax barrier opening array, light emitted from waveguide 74 is not absorbed by the opaque region of the parallax barrier opening array. At a given output from the light source (s) 75, the display 76 of FIG. 28 provides a brighter picture than the display of FIG. 6A with a parallax barrier opening array.

The polarizer 73 acts as a conventional entry polarizer for the image display layer 8. Depending on the mode of operation of the image display layer, a first linear polarizer (not shown) may be provided on the opposite side of the image display layer for polarizer 73.

Display 76 may be fabricated using a method similar to that shown in FIGS. 26A-26D. In this way, an image display element comprising the front substrate 6, the image display layer 8 and the rear substrate is first produced. Thereafter, the back substrate is reduced in thickness to form the transparent layer 72. Next, the polarizer 73 is attached to the transparent layer 72 and the waveguide 74 is attached to the polarizer 73.

Alternatively, the color filter substrate 71 may be manufactured by attaching the polarizer 73 to the waveguide 74. Thereafter, the transparent layer 72 may be attached to the polarizer 73, for example, in the case of the glass transparent layer 72. Alternatively, a transparent plastic or transparent resin layer may be disposed over the polarizer 73 to form the transparent layer 72. Thereafter, the color filter substrate 71 is assembled with the TFT substrate 6 to form the display 76. In this way, waveguide 74 forms the base substrate of color filter substrate 71.

Fig. 29 is a schematic plan sectional view of a multi-screen directional display 76 'according to the fourth embodiment of the present invention. Display 76 'generally corresponds to display 76 of Figure 28, and only the differences are described.

In the display 76 'of FIG. 29, the polarizer 73 is located adjacent to the rear face of the waveguide 74 and attached to the waveguide 74 using, for example, a transparent adhesive (not shown). The refractive indices of waveguide 74, polarizer 73, and adhesive are such that light propagating within waveguide 74 passes into polarizer 73 with virtually no internal reflection at the interface between waveguide 74 and polarizer 73. Is selected. Internal reflection is generated at the rear face of the polarizer 73 as shown by the optical path of FIG.

In this embodiment, the distance between the front face 74c of the waveguide 74 and the image display layer 8 is reduced by the thickness of the polarizer. Light reflected internally at the rear face of the waveguide is polarized during reflection.

30 is a schematic plan cross-sectional view of a multi-screen directional display 77 according to another embodiment of the present invention. The display 77 includes a first transparent substrate 6 and a second transparent substrate 80 having an image display layer 8 disposed therebetween. An array of color filters (not shown) is provided on the second substrate 80, so that the second substrate will be referred to as a color filter substrate.

The first substrate 6 is provided with pixel electrodes (not shown) for forming the pixel arrays 8P, 8S of the image display layer 8, and further includes a thin film transistor TFT for selectively addressing the pixel electrodes. The same (not shown) switching element is provided. The substrate 6 will be referred to as a "TFT substrate". For example, the image display layer 8 is a liquid crystal layer 8. However, the present invention is not limited thereto, and any transparent image display layer may be used.

The display 77 is assembled such that the color filter is substantially respectively opposed to each pixel of the image display layer 8. Other elements, such as an alignment layer, may be disposed on the surface of the substrate 6, 80 adjacent to the image display layer, and the opposite electrode or electrodes may also be disposed on the CF substrate 80. These elements are included in the prior art and will not be described further. In addition, the display 77 may further include elements such as a polarizer, an angle of view enhancement film, an antireflection film, and the like disposed outside the image display element. These elements are also included in the prior art and will not be described any further.

In the present embodiment, the display includes a parallax barrier 79 having a transmissive portion 79a and an opaque portion 79b. In this embodiment, the opaque portion 79a of the parallax barrier 79 polarizes the opening and transmits one polarization while substantially blocking orthogonal polarized light. The pixels 8S and 8P emit / transmit light in the first polarization state or the second polarization state. In Fig. 30, two polarization states are taken to be P- and S-linear polarization states. Pixels named "8S" or "8P" emit / pass S polarized light and P polarized light, respectively. The transmissive portion 79a of the parallax barrier 79 is also named "P" or "S" which names them to transmit S polarized light or P polarized light, respectively.

The parallax barrier 79 is disposed above the base substrate 19. A transmissive spacer layer 78, which can be a glass, transparent resin or transparent plastic layer, is provided between the image display layer 8 and the parallax barrier 79.

The parallax barrier may be formed, for example, with a patterned polarizer having a region that transmits P polarization but blocks S polarization and a region that transmits S polarization but blocks P polarization. Opaque zone 79b may be disposed on the patterned polarizer, for example, by printing. Alternatively, the parallax barrier may be in the form of a combination of a uniform linear polarizer and a patterned retarder having a zone that rotates the polarization plane of light by 90 ° and another zone that does not rotate the plane of polarization of light. The opaque zone 79b can be placed back by, for example, printing.

The parallax barrier 79 is arranged such that the opening 79a that transmits a specific polarization is not in front of the pixel that emits / transmits the polarization. Therefore, the hole 79a for transmitting the P polarization state is not arranged in front of the pixel 8P for transmitting / emitting the P polarization state, and the hole 79a of the parallax barrier for transmitting the S polarization state is used for the S polarization state. It is not arranged in front of the pixel 8S to emit / transmit. As a result, the light transmitted / emitted by the pixel in the polarization state passes through the parallax barrier 79 in different first and second directions, and lies on opposite sides perpendicular to the display surface of the display. For example, light emitted by S pixels parallel or close to the vertical direction is incident on the hole 79a that transmits only P polarized light or on the opaque portion 79b of the parallax barrier. Therefore, the illuminance of the light emitted by the display of this embodiment in the vertical direction or in a direction close to the vertical direction is low. Thus, the apparatus provides a black window between the viewing windows of two images, providing the advantages described with reference to Fig. 11B.

A black mask (named opaque zone 8b) is provided between adjacent pixels 8S and 8R. The angular range of the black center window is changed by changing the pixel ratio (while maintaining the pixel pitch constant) of the black mask. The larger the width of the black mask between adjacent pixels, the larger the angular range of the black center window.

The angular range of the black center window is also determined in accordance with the width of the polarization hole 79a of the parallax barrier 79. The angular range of the black center window can be varied by changing the width of the polarizing hole (while maintaining the hole pitch constant). The smaller the width of the polarization hole of the parallax barrier, the larger the angular range of the black center window.

In any of the above embodiments including a lens array, the lens array may be a GRIN (grade index) lens described with respect to the embodiment of FIG. 20B above.

FIG. 31 illustrates a change in backlight of the display 76 of FIG. The backlight of FIG. 31 includes a first waveguide 74 and one or more first light sources 75 arranged along sides of the first waveguide. Although two first light sources 75 arranged along the opposing side surfaces 74a and 74b of the first waveguide 74 are shown in FIG. 31, the present invention is not limited to this particular configuration, but one light source or 3 More than one light source may be provided. The light source 75 preferably extends along all or substantially all respective side surfaces of the first waveguide and may be, for example, a fluorescent tube.

 Diffusion dots are provided in the selected zone 84 of the rear face 74c of the first waveguide 74. The area 84 where the diffusion tote is present can be, for example, stripe shaped and extend into the paper plane of FIG. When light propagating in the first waveguide is incident on the area 84 of the front face 74c of the waveguide in which the diffusing dot is provided, the light is not specularly reflected and as described with reference to FIG. Scattered outward (in FIG. 31, the viewer is assumed to be at the top of the page, and light is scattered out of the first waveguide 74 in a generally upward direction).

The backlight includes a second waveguide 74 'and one or more second light sources 75' arranged along the sides of the first waveguide. The second waveguide 74 ′ is located behind and is generally parallel with the first waveguide 74. The second waveguide 74 ′ generally corresponds in size and shape to the first waveguide 74. Although the second light source 75 'is shown in FIG. 31 as being arranged along the opposing side surfaces 74a', 74b 'of the second waveguide 74', the present invention is not limited to this particular configuration, but only one. May be used or three or more light sources. The light source 75 'preferably extends along all or substantially all of each side surface of the second waveguide and can be, for example, a fluorescent tube.

Diffusion dots 89 are provided over virtually all front surfaces 74d 'of the second waveguide 74'. Thus, when the second light source 75 'is irradiated, light is scattered out of the front face 74d' of the second waveguide over most of its area.

Thus, the backlight of Fig. 31 is switchable between " patterned mode " and " uniform mode. &Quot; In the "pattern mode", the first light source 75 is irradiated, and the second light source 75 'is not irradiated. Light propagates only in the first waveguide 74, and the backlight does not emit light (corresponding to the region 84 in which the diffusing dots are present) and light (corresponding to the region in which the diffusing dots do not exist). Does not have a zone. In the "uniform mode", the second light source 75 'is irradiated and the light propagates into the second waveguide. Since diffusion dots 89 are provided over substantially the entire front face 74d 'of the second waveguide 74', the backlight provides substantially uniform illumination over the entire area in "uniform mode". The display having the backlight of Fig. 31 can be switched from the directional display mode to the conventional two-dimensional display mode by switching the backlight from "pattern mode" to "uniform mode".

In the "uniform mode", the first light source 75 may or may not be irradiated. If desired, the first light source is successively "ON " and the backlight is " uniform mode " or " pattern mode " by switching the second light source 75 'to " on " or " OFF ", respectively. [Maintaining the patterned waveguide irradiated in uniform mode may cause a change in illuminance over the region of the backlight, but this possible drawback is due to the need to switch only the second light source 75 ' May be important in some applications].

In order for internal reflection to occur at the rear face 74c of the first waveguide, the space between the first waveguide 74 and the second waveguide 74 'has a lower refractive index than the first waveguide 74. This can be conveniently accomplished by providing an air gap between the first waveguide 74 and the second waveguide 74 ', or alternatively the space between the first waveguide 74 and the second waveguide 74' It can be filled with a light transmitting material having a low refractive index.

The rear face of the region 84 where the diffusing dots are provided on the first waveguide 74 may be made reflective, for example by applying a metal coating. When this process is performed, any light scattered towards the second waveguide 74 'by the diffused dots is reflected back towards the viewer (diffusion of the area 84 where the diffused dots are provided on the first waveguide 74). When the rear surface becomes reflective, the reflector is black light scattered upward from the second waveguide 74 ', so it is necessary that the first light source and the second light source be irradiated to obtain a uniform mode.

Each waveguide may be provided with an antireflective coating (not shown).

32 shows another backlight of the present invention. The backlight includes waveguide 74 and one or more light sources 75 arranged along the side of the waveguide. Although two light sources 75 arranged along the opposing side surfaces 74a and 74b of the waveguide 74 are shown in FIG. 32, the present invention is not limited to this particular configuration, and one light source or three or more light sources are Can be used. The light source 75 preferably extends along all or substantially all respective side surfaces of the waveguide and may be, for example, a fluorescent tube.

Waveguide 74 includes a layer of liquid crystal material 87 interposed between two light transmissive substrates 92, 93. The liquid crystal layer is addressable, for example, by an electrode (not shown) which causes an electric field to be applied across the liquid crystal layer 87. Zones 87A, 87B of the liquid crystal layer (indicated by broken lines in FIG. 32) are addressable independently of one another, for example, by the use of suitably patterned electrodes that allow an electric field to be applied across selected zones of the liquid crystal layer. . Zones 87A and 87B of the liquid crystal layer are, for example, stripe-shaped and can extend into the paper plane of FIG.

Zones 87A and 87B of the liquid crystal layer can be switched to scattering mode or clear light transmission mode. When all liquid crystal zones are switched to the light transmission mode, light propagates into the waveguide with minimal scattering. Light experiences internal reflection at the upper surface 92a of the upper substrate 92, passes through the upper substrate 92 and the liquid crystal layer 87 into the lower substrate 93, and lower surface of the lower substrate 93. Internal reflection is experienced at 93b and reflected back toward upper substrate 92 and the like. Light is emitted little or no from the waveguide.

In order to cause the emission of light from the waveguide, one or more liquid crystal zones are switched to form a scattering zone, shown schematically at 85 in FIG. When light propagating within the first waveguide is incident on the scattering zone 85, the light is scattered out of the waveguide described with reference to FIG. 28 (in FIG. 32, assuming the observer is at the top of the page, Light is scattered out of the waveguide 74 in a generally upward direction.

32 shows the waveguide when all of the alternating liquid crystal zones 87A are switched to produce a scattering zone 85. The other liquid crystal region 87B is switched so as not to be scattered. Light is generally emitted only from the area of the front face of waveguide 74 corresponding to scattering area 85 and the backlight operates in a "pattern mode".

When all liquid crystal zones 87A and 87B are switched to form a scattering zone, the liquid crystal layer 87 scatters light over virtually the entire area so that light is emitted from the substantially full area of the waveguide 74. Thus, when all liquid crystal zones 87A and 87B are switched to form a scattering zone, the backlight is operated in "uniform mode". Thus, by switching the liquid crystal region accordingly, the backlight is switched between "pattern mode" and "uniform mode". The display provided with the backlight of Fig. 32 can be switched from the directional display mode to the conventional two-dimensional display mode by switching the backlight from "pattern mode" to "uniform mode".

In the example of the backlight of Fig. 32, the rear surface 92b of the upper substrate 92 is made of a soft material in its entire area. An example of this is a liquid crystal, such as, for example, a polymer-dispered liquid crystal (PDLC), in which layer 87 can be switched between a state that transmits light and a state that scatters light generally without scattering. It needs to contain the material. Scattering zone 85 is obtained by switching the zone of the liquid crystal layer in scattering mode.

Thus, for example, zone 87A of the liquid crystal layer is switched to scattering mode to create scattering zone 85. Light passing from the upper substrate 92 to the region 87A of the liquid crystal layer is reflected up and passed out of the front face of the waveguide 74. Alternatively, zone 87B of the liquid crystal layer is switched to non-scattering mode. Light passing from the upper substrate 92 into the region 87B of the liquid crystal layer is not scattered by the liquid crystal but simply passes to the lower substrate. In the region 87B of the liquid crystal layer in the non-scattering mode, the backlight is in the "pattern mode".

In order to achieve the "uniform mode" of the backlight, all zones 87A and 87B of the liquid crystal layer are switched to scattering mode. Thereafter, the back face of waveguide 74 is generally scattered over its entire area.

In this example, it is also possible to change the size and position of the scattering zone 85 and the non-scattering zone. For example, by switching two adjacent liquid crystal zones into scattering mode, the next liquid crystal zone into non-scattering mode, the next two liquid crystal zones into scattering mode, the next liquid crystal zone into non-scattering mode, and so on, 2: It is also possible to adjust to a parallax barrier with an aperture to barrier ratio of one.

Alternatively, the zones of the rear face 92b of the upper substrate 92 that correspond to certain portions of the scattering zone 85 may be manufactured so rough that these zones always scatter light. The backlight can be switched between "uniform mode" and "pattern mode" by switching the liquid crystal regions 87B respectively in scattering mode or non-scattering mode.

As another alternative, the rear face 92b of the upper substrate may be optically rough over its entire area. This embodiment requires a layer 87 of liquid crystal material having a refractive index that can be varied. The scattering zone 85 is obtained by switching the corresponding liquid crystal zone 87A such that the refractive index of the liquid crystal does not match the refractive index of the waveguide 74. Light propagating in the upper substrate will be scattered by "seeing" the optically rough side of the back side of the upper substrate.

The non-scattering zone is obtained by switching the corresponding liquid crystal zone 87B such that the refractive index of the liquid crystal in the zone 87B does not match the refractive index of the upper substrate 92. Light propagating in the upper substrate will not "meet" at the optically rough surface and will pass through the liquid crystal layer without being scattered (then reflected internally at the rear surface 93b of the lower substrate).

Once the scattering zones are located, a reflector may be provided behind the scattering zone 85, which is shown at 86 in FIG. 32. All light scattered towards the rear substrate 93 by the scattering zone 85 will be reflected by the reflector 86 towards the viewer.

33 shows another backlight. The backlight includes waveguide 74 and one or more light sources 75 disposed along the sides of the waveguide. While two light sources 75 disposed along opposite sides 74a and 74b of waveguide 74 are shown in FIG. 33, the invention is not limited to this particular structure, but only one light source or three or more. Light sources can be used. The light source 75 preferably extends along all or substantially all of each side of the waveguide, and may be, for example, a fluorescent tube.

Diffusion dots are provided in predetermined regions 84 of the rear face 74c of the waveguide 74. The regions 84 where diffusion dots may be present are, for example, strip-shaped and may extend into the paper plane in FIG. As described with reference to FIG. 28 above, when light propagating into the first waveguide is incident on the area 84 of the front face 74c of the waveguide provided with diffusion dots, the light is not reflected like a mirror and the first Scattered from the wave guide (in FIG. 33, the viewer is assumed to be at the top of the page, and light is generally scattered from the first waveguide 74 in the upward direction).

Lens array 88 is disposed in front of waveguide 74. The lens array directs light emitted by the waveguide 74 mainly in the first direction (or direction of the first range) 90 and in the second direction (or direction of the second range) 91. The first direction (or direction of the first range) 90 and the second direction (or direction of the second range) 91 are preferably separated by a third range of directions including the vertical direction. Since light is primarily directed in the first and second directions (or directions of the first and second ranges) 90, 91, the first and second directions (or directions of the first and second ranges) 90, 91), the illuminance of the light is greater than the illuminance in the direction of the third range. The first direction (or direction of the first range) 90 and the second direction (or direction of the second range) 91 are on opposite sides of the vertical direction and are preferably generally symmetrical about the vertical.

The backlight of Figure 33 is particularly suitable for use with directional displays. A typical dual view display displays, for example, two pictures displayed along a direction lying on opposite sides of the vertical direction. The backlight in FIG. 33 mainly directs the light in the direction in which the two images are displayed by the dual screen display, producing a bright image. In contrast, conventional backlights have the highest illuminance along the vertical direction and have low illuminance when viewed off the axial direction.

A four screen illumination system can be manufactured using microlenses in a 2D array and diffused dots in a 2D array. This will provide four screens with two screens arranged on top of two screens, providing separate screens both horizontally and vertically.

34 shows another backlight. This backlight is similar to the backlight of FIG. 33 in that a lens array is provided that directs the emitted light in two preferred directions (or direction ranges) 90,91. The backlight of FIG. 34 includes a second waveguide 74 'and a second light source 75' disposed along each side of the second waveguide 74 '. Diffusion dots 89 are provided for the entire front face of the second waveguide 74 '. The second waveguide 74 'of FIG. 34 generally corresponds to the second waveguide 74' of FIG. The backlight of FIG. 34 may be switched between "pattern mode" and "uniform mode" in the manner described above for the backlight of FIG.

31-34 may be mounted to, for example, display 76 of FIG. 28 or display 76 'of FIG.

31 to 34, the density of the diffused dots can be adjusted to change the spatial illumination uniformity, so that increasing the distance from the light source 75 compensates for the reduction in the illuminance of the light propagating in the waveguide. This may apply to all waveguides of the embodiment of FIGS. 31 and 34.

In the embodiment of Figs. 31 to 34, diffusion dots may be replaced with micro reflective structures such as prisms, protrusions, and the like. This can be used, for example, to control the radial direction from the region of the waveguide in which the diffuse dots are stored.

In the above-described embodiments, the parallax optics were disposed on the same substrate as the color filters. Alternatively, it is also possible to arrange parallax optics on the TFT substrate 6 of the display, and there is a corresponding embodiment in which parallax optics are provided on the TFT substrate for all the above-described embodiments where the parallax optics are provided on the color filter substrate. . In this modified embodiment, a spacer layer can be inserted between the parallax optics and the thin film transistors, while an element of parallax optics and an array of switching elements, such as an array of TFTs, will be placed over the base substrate of the TFT substrate. The separation between the parallax barrier and the image display layer is again generally the thickness of the spacer layer (assuming that the spacer layer is disposed over the parallax optics). In particular, in the embodiment of Figs. 22 to 25, a prism 53 may be disposed on the TFT substrate.

Alternatively, in some liquid crystal panels, color filters are disposed on the same substrate as the thin film transistors. The present invention can also be applied to such a device. For example, a light transmissive spacer layer (eg, a resin, glass or plastic spacer layer) can be disposed over the color filters and TFTs (or other switching elements), and the parallax optic can be disposed over the spacer layer.

Except for those shown in FIGS. 22-25 and 28-34, embodiments of the present invention may be used as a front barrier device (shown in FIG. 1) or a rear barrier device (shown in FIG. 4).

When the apparatus of the present invention, wherein the parallax optic is a parallax barrier, is used in the rear barrier mode of Fig. 4, it is preferable that the parallax barrier element is reflected on the surface facing the backlight. Thereafter, light from the backlight incident on the opaque region of the barrier can be reflected, reflected from the backlight and passed through the parallax barrier and through the display device. This increases the brightness of the display. The surface of the parallax barrier element facing away from the backlight is preferably absorbent, preventing crosstalk.

The present invention has been described above with respect to an image display element comprising a liquid crystal layer. However, the present invention is not limited to this particular image display element, and any suitable image display element may be used. For example, an OLED (organic light emitting device) image display element can be used.

According to the present invention, it is possible to provide a multi-screen directional display capable of increasing the angular interval between two viewing windows generated by the display device.

1 is a schematic plan view of a conventional automatic stereoscopic display device.

2 is a schematic view of a viewing window provided by a conventional multi-screen display device.

3 is a schematic plan view of a viewing window manufactured by another conventional multi-screen directional display device.

4 is a schematic plan view of another conventional autostereoscopic display device.

5 is a schematic plan view showing main components of a conventional multi-screen directional display device;

6A and 6B show a display according to a first embodiment of the present invention;

6C and 6D illustrate a display according to another embodiment of the present invention.

7A and 7B illustrate a display according to another embodiment of the invention.

8A and 8B illustrate a display according to another embodiment of the present invention.

9A and 9B illustrate a display according to another embodiment of the present invention.

10A and 10B illustrate a display according to another embodiment of the present invention.

11A and 11B illustrate a display according to another embodiment of the present invention.

12A and 12B illustrate a display according to another embodiment of the present invention.

13A and 13B illustrate a display according to another embodiment of the present invention.

14A and 14B illustrate a display according to another embodiment of the present invention.

14C and 14D show a display according to another embodiment of the present invention.

15A and 15B illustrate a display according to another embodiment of the present invention.

15C and 15D show a display according to another embodiment of the present invention.

16A and 16B illustrate a display according to another embodiment of the present invention.

17A and 17B illustrate a display according to another embodiment of the present invention.

18A and 18B illustrate a display according to another embodiment of the present invention.

19A and 19B illustrate a display according to another embodiment of the present invention.

20A and 20B illustrate a display according to another embodiment of the present invention.

20C and 20D illustrate a color filter substrate of a display according to another embodiment of the present invention.

21A and 21B illustrate a display according to another embodiment of the present invention.

21C and 21D show a color filter substrate of a display according to another embodiment of the present invention.

Figure 22 illustrates a display according to another embodiment of the present invention.

Figure 23 shows a display according to another embodiment of the present invention.

Figure 24 shows a display according to another embodiment of the present invention.

25 illustrates a display according to another embodiment of the present invention.

26A-26D illustrate a method of manufacturing the display of the present invention.

Figure 27 illustrates a display according to another embodiment of the present invention.

Figure 28 shows a display according to another embodiment of the present invention.

Figure 29 illustrates a display according to another embodiment of the present invention.

30 illustrates a display according to another embodiment of the present invention.

Figure 31 illustrates a backlight suitable for use in the display of the present invention.

Figure 32 illustrates another backlight suitable for use in the display of the present invention.

Figure 33 illustrates another backlight suitable for use in the display of the present invention.

Figure 34 illustrates another backlight suitable for use in the display of the present invention.

<Explanation of symbols for the main parts of the drawings>

6, 7: substrate

13: parallax barrier opening array

14: Opaque Strip

18: color filter

19: base substrate

20: light transmitting layer

23: display

26 recess

74: waveguide

Claims (41)

A multi-screen directional display with picture display elements and parallax optics 13, 13 ', 35, 35', 35 '', 35 '' ', 42, 46, 67, 79, 84, The image display elements may be formed of the first substrates 7, 25, 25 ', 29, 31, 31', 34, 34 ', 34' ', 34' '', 36, 39, 39 ', 44, 49, 49', 68, 71, 80, a second substrate 6, and an image display layer 8 interposed between the first substrate and the second substrate, A parallax optic is a display disposed within an image display element. The display of claim 1, wherein the parallax optic is disposed between the first substrate and the second substrate. 2. The parallax optics 13, 13 ', 35, 35', 35 '', 35 '' ', 42, 46, 67, 79, 84 are disposed in one of the first substrate or the second substrate. Display. The display of claim 3, wherein the parallax optic is disposed within a thickness of the first substrate. 5. A display according to claim 4, wherein the parallax optics comprise a plurality of parallax elements, each parallax element disposed in each recess (26) on the major face of the first substrate (25, 25 ', 31). The substrate of claim 4, wherein the first substrate comprises a base substrate 19 and a light transmitting layer 20 disposed over the base substrate, and the parallax optics are disposed between the light transmitting layer 20 and the base substrate 19. display. The substrate of claim 4, wherein the first substrate comprises a base substrate 19, a light transmitting layer 20 disposed over the main surface of the base substrate, and a plurality of recesses 26 formed in the light transmitting layer 20. , A parallax optic (13) comprises a plurality of parallax elements, each parallax element disposed in each recess (26) in the light transmitting layer (20). 8. Display according to claim 5 or 7, wherein each parallax element is disposed on the bottom face of each recess (26). 8. Display according to claim 5 or 7, wherein the cross section of the recess (26) parallel to the surface of the substrate is reduced with depth. 10. A display according to any one of claims 5, 7, 8 and 9, wherein each parallax element generally fills each recess (26). The display according to claim 4, wherein the color filter array (18) or the switching element array is disposed on the major surface of the first substrate. 12. The display according to claim 11, further comprising a light transmitting layer (20) disposed between the switching element array or the color filter array (18) and the parallax optics. 13. A display according to claim 11 or 12, further comprising another parallax optic (13 ') disposed between the switching element array or color filter array (18) and the parallax optic (13). The display according to claim 5, wherein the color filter array (18) or the switching element array is disposed on the second major surface of the first substrate. The light transmitting layer 20 according to any one of claims 1 to 4, wherein the light transmitting layer 20 and the image display layer 8 and the parallax optics 13, 13 ', 35, 35', 35 '', 35 '' ', 42, 46) disposed between. 16. A display according to claim 15, wherein one of the switching element array and the color filter array (18) and the parallax optics are disposed on the major surface of the base substrate (19), the base substrate being included in the first or second substrate. 17. The color filter array 18 or the switching element array according to claim 16, wherein the parallax optics 13, 35, 35 ', 35 &quot;, 35' &quot;, 42 are disposed on the first major surface of the base substrate. The display is placed above the parallax optics. 17. The display according to claim 16, wherein the color filter array (18) or switching element array is disposed on the first major surface of the base substrate and the parallax optics (13) are disposed over the color filter array or switching element array. 19. A display according to claim 17 or 18, wherein the light transmitting layer (20) is disposed between the switching element array or the color filter array (18) and the parallax optics. 20. The display as claimed in claim 17, further comprising another parallax optic (13 ′) disposed between the switching element array or the color filter array (18) and the parallax optic (13). 17. A display according to claim 16, wherein the parallax optics comprise a plurality of parallax elements, each parallax element disposed in each recess (26) of the major surface of the first or second substrate. The second light transmitting layer 32 is disposed on the major surface of the base substrate 19, and the second light transmitting layer 32 is the first light transmitting layer 20 and the base substrate 19. A plurality of recesses 26 are formed in the second light transmissive layer 32, the parallax optics comprise a plurality of parallax elements, each parallax element having a respective recess of the second light transmissive layer 32. Display placed in the set. The method of claim 15, wherein one of the switching element array and the color filter array 18 is disposed above the first major surface of the base substrate 19, and the parallax optics are disposed on or above the second major surface of the base substrate, The base substrate (19) is included in the first or second substrate (25 ', 6). 24. A display according to claim 23, wherein the parallax optics comprise a plurality of parallax elements, each parallax element disposed in each recess (26) of the second major surface of the base substrate. The display according to claim 21, 22 or 24, wherein each parallax element is disposed on the bottom face of each recess (26). The display according to claim 21, 22 or 24, wherein the cross section of the recess parallel to the face of the substrate decreases with depth. 27. The display of claim 26, wherein each parallax element generally charges each recess. 28. The method of any one of claims 6, 7, 12, 15-27, or 12, or 12, when quoting 7 Display according to claim 13, wherein the light transmitting layer (20) is a transparent resin layer. 28. The method of any one of claims 6, 7, 12, 15-27, or 12, or 12, when quoting 7 Display according to claim 13, wherein the light transmitting layer (20) is a laminated plastic layer. 28. The method of any one of claims 6, 7, 12, 15-27, or 12, or 12, when quoting 7 Display according to claim 13, wherein the light transmissive layer (20) is a glass layer. 31. A display according to any one of the preceding claims, wherein the parallax optic is a parallax barrier (13, 13 '). 32. A display according to any one of the preceding claims, wherein the parallax optics are lenticular lens arrays (35, 35 ', 35' ', 35' ''). 33. A display according to any one of the preceding claims, wherein the parallax optics can be suppressed. 34. A display as claimed in any preceding claim, wherein the parallax optics are addressable. 35. A dual screen display device comprising a multi screen directional display as defined in any of claims 1 to 34. 35. An autostereoscopic display device comprising a multi-screen directional display as defined in any of claims 1 to 34. A parallax optic comprising a light transmissive substrate and a plurality of parallax elements, each parallax element disposed in each recess of a face of the substrate. 38. The parallax optics of claim 37, wherein a cross section of the recess parallel to the face of the substrate decreases with depth. 39. The parallax optics of claim 38, wherein each parallax element generally fills each recess. Is a method of manufacturing a display device, (a) of a first substrate 60 of an image display element comprising a first substrate 60, a second substrate 61, and an image display layer 8 disposed between the first and second substrates. Reducing the thickness, (b) attaching a third substrate (62) to the first substrate with disparity optics (13) disposed therebetween. 41. The method of claim 40, wherein the parallax optic 13 is defined on or above the first major surface of the third substrate 62, and step (b) is performed on the first substrate of the image display element. Attaching a face.