KR100211900B1 - The image display apparatus - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an image display device, wherein an image segmentation and a shift for improving the image quality of an image projection display device using a single-plate flat panel (flat display device) in which an image is displayed on a pixel basis. shift) technology.

Conventional image projection display apparatuses use a multi-faceted flat plate or a multi-sided prism to perform image segmentation and shifting by wavefront dividing so that an image from which a partition is removed is formed on a screen.

Therefore, deterioration of image quality due to scattered light generated at the surface boundary of the multi-faceted optical element is caused, and manufacturing of the multi-faceted optical element is difficult, and the multi-sided optical element is dependent on the lens system, making design difficult.

According to the present invention, a pixel obtained by copying an original pixel by dividing light of an image image output from a flat panel into two by an amplitude division method using a birefringent plate of a flat plate and moving one of the lights appropriately in any direction is used. By independently projecting to an independent position, the original pixel and the replicated pixel can display an image, thereby doubling the pixels actually observed when the image is observed, fundamentally eliminating the deterioration of image quality due to scattered light, and also providing a flat optical element. The present invention provides an image projection display device that facilitates production and design.

Description

Image display

1 is a diagram illustrating a conventional image segmentation and shift concept.

Fig. 2 is a diagram showing the configuration of an image projection marker apparatus in a practical manner as a first example of an image projection display apparatus.

3 is a diagram showing the configuration of an image projection display device by a virtual image method as a second example of the image projection display device.

Fig. 4 is a diagram showing the shape of a pixel in the delta method.

5 is a diagram showing the shape of a pixel in the stripe method.

6 shows a first example of a conventional image projection display.

7 shows a second example of a conventional image projection display.

8 is a view for explaining a light scattering phenomenon in the first conventional example.

Fig. 9 is a diagram showing the concept of image division shift by the image display device of the present invention.

10 is a diagram showing an embodiment configuration of an image display device of the present invention.

11 is a view showing the light transmission and refraction principle of the birefringent plate applied in the present invention.

12 is a diagram for explaining the above-mentioned FIG. 10 in more detail.

Fig. 13 is a diagram showing the shape of a green pixel in the delta method.

FIG. 14 is a view showing a state in which the green pixel of FIG. 13 is divided and shifted by the image display device of the present invention. FIG.

* Explanation of symbols for main parts of the drawings

101 liquid crystal display panel 102 birefringent plate

103: projection lens 104: screen

105: original R pixel 105a: duplicated shift R pixel

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an image display device, wherein the image segmentation and shift for improving the image quality of an image projection display device using a single-plate flat panel (flat display device) in which an image is displayed on a pixel basis. It is about technology.

In particular, the present invention divides the light of the image image output from the flat panel into two, and appropriately shifts one of the lights in an arbitrary direction to independently project the pixel copied from the original pixel to a position independent of the original pixel, The present invention relates to an image projection display device in which an original pixel and a duplicated pixel display an image so that a pixel substantially observed upon image observation can be doubled.

In the prior art, in the case of an image projection display apparatus using a liquid crystal display panel (LCD panel), a technique of removing partition walls by performing division and shift of an image has been proposed.

A concept of conventional image segmentation and shift will be described with reference to FIG. 1.

In screen projection of an image by R (Red), G (Green), and B (Blue) pixels of a liquid crystal display panel, an area on which an image is not displayed appears on an image on the screen due to a partition wall between pixels.

This is due to the partition between the pixels of the liquid crystal display panel, the gap between the R pixel 1, the G pixel 2, and the B pixel 3 is inevitably shown by the partition wall 4, and this gap is formed on the screen. It appears as a mosaic pattern in the image, which causes a deterioration in image quality.

In order to prevent such deterioration of the image quality due to the barrier rib, the original pixel is divided by an optical element and shifted by a direction and a distance from which the barrier rib can be removed and shifted by the shifted pixels 1a, 1b, and 1c. The image is projected onto the screen together with the image by the original pixel.

In this case, the shifted amount is divided into a plurality of images and moved in a specific direction by an amount less than the pixel period to remove the partition wall.

As described above, a technique for removing the partition wall is applied to an image projection display device using a liquid crystal display panel, and the image projection display device includes a real method and a virtual image method.

In fact, as shown in FIG. 2, the liquid crystal display panel 5 includes an arrangement of a liquid crystal display panel 5, a projection lens 6, and a screen 7, and is outside the focal length f of the eyepiece lens. The liquid crystal display panel 5 is positioned so that the actual image projected on the screen 7 is visible. In the virtual image method, as shown in FIG. 3, the eyepiece 8 and the liquid crystal display panel ( 9), an arrangement of the screens 10, in which the liquid crystal display panel 9 is positioned inside the focal length f so that the virtual image 10 by the liquid crystal display panel is visible.

In either case, the image of the liquid crystal display panel is enlarged and projected on the screen, and the problem of the partition wall remains as it is.

The liquid crystal display panel has a delta method as shown in FIG. 4 and a stripe method as shown in FIG. 5 according to the arrangement of pixels.

In the delta method, R, G, and B filters are sequentially arranged in the horizontal direction, and in the relationship between adjacent horizontal lines, 3/2 pixels are arranged to move in the horizontal direction.

In addition to the liquid crystal display panel (LCD panel) described above, a PDP panel, a FED panel, a DMD panel, or the like may be applied as a flat panel panel capable of projecting an image.

In any case, the image using the flat panel is enlarged even when the projection lens is projected by the projection lens, so that the pixels are recognized as separated by the partition unless the image is observed from the screen by a sufficient distance.

Therefore, the image is observed as if all the pixels constituting the image are recognized and the image is not natural, and the image quality is very degraded.

In order to overcome this disadvantage, image segmentation and shifting techniques such as those shown in FIG. 1 are introduced.

In other words, by copying pixels (images) and projecting the image by the original pixel and the shifted copy image on one screen, the image quality resistance by the partition wall is removed, and the focus is on the removal of the partition wall.

For image duplication, a wavefront division method is used which divides the wavefront of light starting at each point of each image by the liquid crystal display panel.

FIG. 6 is a first example of a conventional image projection display apparatus that performs image segmentation and shifting using a wavefront segmentation method (US Pat. No. 5,250,967), showing an image segmentation and shift technique using a multi-faceted flat plate. Figure 2 shows an image segmentation and shift technique using a multi-sided prism as a second example (US Pat. No. 5,005,968).

The above techniques are techniques for dividing a plurality of images into a position close to the projection optical system and the aperture and moving the components in a specific direction by an amount less than the pixel period.

The conventional image projection display device using the multi-faceted flat panel shown in FIG. 6 includes a liquid crystal display panel 11, an illumination system 12, an aperture 13, a multi-faceted flat panel 14, a projection lens 15, and a screen 16. It consists of.

The liquid crystal display panel 11 outputs light having image information as an image identity to be projected onto the screen, and the output light is incident on the flat plate 14 through the aperture 13.

Light incident on the multi-faceted flat plate 14 is wavefront divided at each curved surface of the multi-faceted flat plate 14 to project the image by the original pixel and the divided duplicate image to the 16 through the projection lens 15.

The shape of the pixel (image) projected on the screen 16 is the original image and the duplicated image, which are divided and shifted, as shown in FIG.

As shown in FIG. 8, the division and the shift of the image are performed by the wavefront division and the shift of the incident light on a plurality of surfaces of the multi-faceted flat plate 14, and thus the original image 24a by the refracted light 23a, and The duplicated and shifted image 24b is obtained.

However, an important problem is exposed here.

The scattering of incident light occurs at the boundary (edges) 14a, 14b, 14c constituting a plurality of planes, and the scattered light 23b causes unwanted images to be projected on the screen in a very irregular and scattered form.

This is provided as a cause of the deterioration of the image quality of the new form, in contrast to the image quality improvement by the removal of the partition wall.

The image, as if the shadow is erased like a ghost, is projected on the screen by the scattered light at the surface boundary of the flat plate.

Therefore, according to the prior art of Fig. 6, the image quality deterioration due to the partition wall can be improved as seen in Fig. 1, but a new problem is that unwanted images of scattered light by the flat plate are projected.

Further, in the prior art of FIG. 6, since the multi-faceted flat plate 14, which is a multi-faceted refractive optical part, must be inserted at the aperture 13 of the projection optical system, the dependency of the projection optical system is very large.

This limits the design of the projection lens and the image projection display system.

In addition, since the exact amount of division and shift is required to obtain the duplicated image, it is difficult to manufacture the multi-faceted plate 14.

On the other hand, the conventional image projection display using the multi-sided prism shown in FIG. 7 includes an illumination system 17, a liquid crystal display panel 18, an aperture 19, a projection lens 20, a multi-sided prism 21, and a screen ( 22).

The liquid crystal display panel 18 outputs light having image information as an image identity to be projected on the screen, and the output light is incident on the multi-side prism 21 via the aperture 19 and the projection lens 20.

Light incident on the multi-sided prism 21 is wavefront divided at each curved surface of the multi-sided prism 21 to project the image by the original pixel and the divided duplicate image onto the screen 22.

The shape of the pixel (image) projected on the screen 22 is an original image and a duplicated image, which are divided and shifted, as shown in FIG.

The division and shift of the image by the multi-sided prism are based on an operation very similar to that shown in FIG.

Therefore, this technique also has problems in the technique using the multi-faceted flat plate of FIG.

As a conventional technique, as an image segmentation and shifting technique for removing a partition, a micro lens array sheet in which one micro lens corresponds to each pixel of the liquid crystal display panel is used (US Patent No. 5,300,942). ), Or a technique using a grating sheet is also presented.

However, the technique using the microlens array plate has a large manufacturing difficulty since the microlenses must be disposed to correspond precisely to each pixel of the liquid crystal display panel.

In addition, the deterioration of image quality due to scattering as described above cannot be avoided at the boundary portions of the microlenses.

Also, even in the technique using the grating sheet, undesired scattering caused by the edges of the grating sheet causes a deterioration in image quality, and a moire caused by interference between gratings is generated on the pixels of the liquid crystal display panel. There is a possibility of deterioration of image quality.

On the other hand, in the case of the conventional liquid crystal display panel image as described above, the image should be observed far from the screen so that the pixels are not visible. In this case, the viewing angle is narrowed and the viewing space is so large.

Summarizing the problems in the conventional techniques as described above are as follows.

First, since the division and shift of the image are intended to remove the partition wall, the image is moved by an amount less than the pixel period, and the parts using wavefront segmentation methods such as a multi-faceted panel, a multi-faceted prism, a micro lens array plate, and a grating sheet are used. It is difficult to exclude the influence of the scattered light because it is implemented.

Secondly, since the division and shift parts should be located at the aperture positions of the projection optical system, the component dependence is large, and this limits the design and arrangement of each part of the image projection display device.

Third, the aberration characteristic of the projection optical system is inferior by the refractive optical system such as a polyhedral element inserted at the aperture insertion position.

Fourth, since the microlenses or the gratings should be arranged at positions corresponding to the pixels of the liquid crystal display panel, manufacturing becomes difficult.

The above problems are the same in the delta method as well as the stripe method.

The present invention solves these problems and can be applied not only to liquid crystal display panels but also to HMD panels, PDP panels, DMD panels, etc. as flat panel display panels, and to image display apparatuses applied regardless of the delta method or the stripe method. To provide.

That is, an object of the present invention is an image projection display device using a single-plate flat panel, in which a replicated pixel is projected independently at a position independent of the original pixel to substantially increase the number of pixels to improve image quality. To provide.

It is still another object of the present invention to provide an image display device using a single-plate flat panel, in which image quality deterioration due to scattered light does not occur during division and shift of an image.

It is still another object of the present invention to provide an image display device using a single-plate flat panel, in which image degradation and image quality degradation due to scattered light do not occur in the shifted yarns.

Still another object of the present invention is to provide an image display apparatus for reducing the dependency of optical elements, simplifying the configuration of the optical system, and facilitating the production thereof in an image projection display apparatus using a single plate flat panel.

The image display device of the present invention, which achieves the above object, increases the number of pixels of a screen image by dividing the pixels of the image formed by the image display means and shifting them at least larger than the pixel period, thereby improving the image quality. Expectations have that feature.

Further, the present invention is characterized by performing division and shifting on a flat plate by using an amplitude division method in dividing and shifting an image region formed in the image display means.

In addition, the present invention is further characterized by increasing the number of pixels of the screen image in the shift direction by moving in the diagonal direction as well as in the vertical direction.

In addition, the present invention further includes an optical means by changing the polarization direction of the light having the image information formed in the image display means to implement an image display device.

9 shows the concept of division and shift in the image display device of the present invention which achieves the above objects and has the features.

The R, G, and B pixels that implement the screen image are copied and shifted by an amount greater than at least the pixel period.

FIG. 10 shows an embodiment of an image display apparatus in which image division and shifting as shown in FIG. 9 are performed.

As a matter of course, the present invention can also be extended to a flat panel display panel using a flat panel display panel such as a PDP panel, a FED panel, a DMD panel, and a stripe type flat panel display panel.

The image display device of FIG. 10 includes a liquid crystal display panel 100 as means for displaying an image in pixel units, and a flat plate 101a for polarizing meaningful light having image information displayed on the liquid crystal display panel 100. 101b and a double refraction plate 102 as optical means for dividing and shifting the light passing through the polarizing plate 101a, and the light split and shifted by the birefringence plate 102 to be enlarged and projected. And a screen 104 on which an image enlarged by the projection lens 103 is formed.

At this time, the polarization axis of the flat plate 101a is arranged to have a direction of 45 ° with respect to the crystal optic axis of the birefringent plate 102.

In this embodiment, since the light having the image information displayed on the liquid crystal display panel 100 has only one component which is horizontal or perpendicular to the ground, the polarization direction with respect to the ground using the polarizing plate 101a is Polarize to have both vertical and horizontal components.

Light having image information passing through the polarizing plate 101a is incident on the birefringent plate 102, and the birefringent plate 102 separates two pixels of the incident light, one through the projection lens 103 and the screen 104. ) Is projected as an image by the original pixel, and the other is projected as an image in which the original pixel is duplicated on the screen 104 through the projection lens 103.

11 and 12 illustrate the structure and principle of the birefringent plate 102, which divides light into two and moves one of them to a specific position.

The crystal optical axis 102a of the birefringent plate 102 has a predetermined angle θ when viewed in the thickness t direction with respect to the incident light 103.

The incident light 103 passes through the polarizing plate 101a and has both the component 103a and the horizontal component 103b whose polarization directions are perpendicular to the ground.

The birefringent plate 102 separates the incident light 103 into two in accordance with the polarization direction along the crystal optical axis.

One light is the light 104a corresponding to the original pixel through which the vertical component 103a of the incident light 103 is passed as it is, and the other light makes the horizontal component 103b of the incident light 103 at a predetermined angle ( The light 104b is refracted by α) and moved by a predetermined distance 1 with the light 104a corresponding to the original pixel.

In other words, division / shift by amplitude division is performed.

The divided shifted light 104b has duplicated image information, and the shifted amount 1 is an amount larger than the period of the pixel, which corresponds to 1.5 times the pixel period in FIG.

The separated width 1 is given by the following equation.

Where n _e is the refractive index for the abnormal light, n _o is the refractive index for the normal light, and t is the thickness of the birefringent plate.

The straight light is perpendicular to the ground and is called an ordinary wave. The light traveling by d is polarized in parallel to the ground and is called an extraordinary wave.

The material of the birefringent plate 102 may include artificial quartz, calcite, LiNbO _3, and the like.

As shown in the above equation, by properly adjusting the thickness t of the birefringent plate 102 and the direction of the optical axis 102a, the pixels of the liquid crystal display panel 101 can be doubled.

For example, when d = 3 / 2Px and Px are horizontal pitches of the pixels of the liquid crystal display panel and are 1.5 times the pixel period, the image generated by the birefringent plate 102 is screened through the projection lens 103. When magnified projection is made to 104, as shown in FIG. 9, the R height 105 can project an image increased by twice (105, 105a).

This duplicated image has all the original image information and is displayed independently at a position independent of the original image.

Since the number of pixels is increased by twice as much as 1.5 times the pixel period, the partition is naturally removed.

As shown in FIG. 13, the division and shift of the delta type G pixel are performed by the original G pixel 106 and the copied G pixel 106a as shown in FIG. The pixel is also doubled.

Similarly, a pixel that is doubled also is projected on the B pixel.

Therefore, an image of a resolution in which the number of pixels constituting the screen image has been doubled is projected onto the screen 104.

As shown in the above equation, the division / shifting of the image in a direction perpendicular to the ground by the crystal optical axis of the birefringent plate 102 and its arrangement is also easily realized.

Naturally, it is also simply implemented to divide / shift the image diagonally with respect to the ground.

In addition, since the birefringent plate 102 is a flat plate, there is no scattered light generated when using a conventional multi-faced flat plate.

Therefore, the degradation of the image quality due to the scattered light is essentially eliminated.

In addition, since the birefringent plate 102 is provided near the flat panel display panel and can be installed independently of other optical systems (projection lens, aperture, etc.), there is no dependency.

Means for displaying an image by said pixel unit and as a signal source of an image to be visible; In the case of displaying an image by controlling the amount of light transmitted in units of pixels, a liquid crystal display panel is used.

However, if a means of displaying an image by controlling the amount of reflection of light on a pixel-by-pixel basis, a DMD projector may be used.

Alternatively, the PDP may be used if the means for displaying the image by controlling the plasma discharge amount on a pixel basis is applied.

In addition, the FED may be used if a means for displaying an image is applied by controlling the intensity of the collision amount by electron emission on a pixel-by-pixel basis.

If the configuration of the image display means of the present invention and the optical means for dividing / shifting is applied to an apparatus for enlarged projection of an image, it includes means for enlarging and projecting the original image formed by the birefringent plate and the divided / shifted image. Applied to an enlarged projection apparatus of an image.

In FIG. 10, the projection lens 103 is used.

As described above, the image display device of the present invention well represents the features of the present invention.

Since the image display device of the present invention does not use a multi-faceted optical element such as a multi-faceted flat plate or a multi-sided prism, the image display device essentially eliminates the deterioration of image quality due to scattered light. It ensures image quality.

In addition, the use of planar dividing / shifting optics makes it easy to fabricate and is quite independent of other optics, so there is no dependency on the system design and component arrangement.

The image display device of the present invention displays the duplicated pixels independently of the original pixels, and the pixel pitch is reduced to 1/2 so that the viewer can reduce the viewing distance from the screen to half.

Therefore, viewing is possible at twice the field of view compared to the prior art, and the system can be installed and operated even in a narrow viewing space.

Claims (10)

An image is displayed in units of pixels, and the displayed image is divided into image display means provided as a signal source of an image for viewing, and a pixel of an image formed by the image display means is divided into meaningful elements of the original pixel and the original pixel. And optical means for dividing the duplicated pixel into information which is intact and placed in an independent position, and shifting the duplicated pixel by an amount greater than at least the period of the pixel. An image display apparatus according to claim 1, further comprising means for enlarging and projecting an image in which the image of the image display means is divided by the optical means and shifted. The image display apparatus according to claim 1 or 2, wherein said image display means is means for displaying an image by controlling the amount of light transmitted per pixel. The image display apparatus according to claim 1 or 2, wherein the image display means is a means for displaying an image by controlling the amount of light reflection in units of pixels. 3. An image display apparatus according to claim 1 or 2, wherein said image display means is means for displaying an image by controlling an amount of plasma discharge on a pixel basis. An image display apparatus according to claim 1 or 2, wherein said image display means is means for displaying an image by controlling the intensity of the collision amount with the screen by electron emission on a pixel-by-pixel basis. The image display device according to claim 1 or 2, wherein the shifted amount is shifted to 1.5 times the pixel period. 3. The optical means according to claim 1 or 2, wherein the optical means has any one of two components with respect to a component in which the image signal source (light) in the image display means is horizontal and vertical in the polarization direction with respect to the ground. The component of the image display device comprising an optical element for passing the component of the visible to the original image by the original pixel, the other component is refracted to be visible as a duplicate image of the original pixel. The image display apparatus according to claim 8, wherein the optical element is a flat plate as a birefringent plate. An image is displayed in units of pixels, and the displayed image includes image display means provided as a signal source of an image for visibility, and a component in which the image signal source (light) in the image display means is horizontal with respect to the ground. Means for converting the light into a component perpendicular to the light of the light source, and one of the two lights converted by the converting means passes as image information corresponding to the original pixel, and the other light duplicates the original pixel. And optical means for shifting at least an amount larger than the period of the pixel as information, and means for enlarging and imaging an image by an original pixel formed by the optical means and an image by a duplicated pixel on the screen. Image display device.