WO2000075724A1 - Light-shielding plate for projection video apparatus - Google Patents

Abstract

Images are projected onto screens (16) by projection video apparatuses (55, 60) and the edges of the images are connected to each other to form a wide image. An improved light-shielding plate (11) for adjusting the luminance at the connected part (T) by blocking the edge part of the projected light beam is placed in front of the projection lens of a video producing unit provided in each of the projection video apparatuses (55, 60). The light-shielding plate is a filter, the transmittance of which gradually decreases from the center of the projected light beam to its periphery, making it a density gradient shielding plate (21, 22, 23, 24).

Description

Description ^: Light shielding plate for projection type video device [Technical field]

 The present invention relates to a light shielding plate of a projection type video device, and more particularly to a light shielding plate of a projection type video device such as a video video projector in continuous multi-screen.

[Background technology]

 In recent years, video display devices have evolved from television devices that can be viewed by a small number of people at home, and have evolved into large-scale, multi-projection video devices, such as movie displays for airplanes.

 Such video projectors include large-sized CRT CRTs with high-brightness light emission, liquid crystal transmissive projectors, liquid crystal reflective projectors such as ILA, and DLPs (reflective projectors with fine mirrors). Various projection devices have been developed.

 In addition, single lenses have become more common than conventional three-lens systems, and the light output of the projection device has increased two to three times.

 A projection type video device in a continuous multi-screen, that is, a video video projector will be described with a liquid crystal reflection type projection device such as a conventional ILA as a representative.

 Fig. 7 shows the basic configuration of a video image projector.

 A video (video) signal from a video playback device (VTR, etc.) 1 is sent to the video generation laminate 2 via the pixel control unit 8 to generate video (optical) light. Image light composed of each color light is incident on the polarization beam splitter 3.

High-brightness white light is simultaneously incident on the polarizing beam splitter 3 from the light source lamp 4 from the 90 ° direction beside it. The light source lamp 4 is a highly directional xenon lamp or the like, and the emitted white light waves are synchronized coherent waves (coherent). This white light is combined with the image light composed of each color light by the polarization beam splitter 3 to become image light composed of each color light with extremely high brightness (high-brightness image light) and is incident on the projection lens (double-sided convex lens) 5. You.

 The projection lens 5 refracts the luminance image light, and projects the image light L enlarged in proportion to the distance to a distant white screen 6.

 On the white screen 6, an image (optical) generated from the image electric signal by the image generation laminate 2 is largely displayed. When only the image light from the image generating laminate 2 is directly projected onto the white screen 6 by the direct projection lens 5, the brightness is low, and when the environment in which the white screen 6 is placed is bright, almost the white screen 6 The image disappears.

 Therefore, the light from the light source lamp 4 is used to intensify the image light from the image-generating laminate 2 with the polarizing beam splitter 3 using the strong light from the light source lamp 4, so that the image on the white screen 6 has high brightness and is clearly visible. ing.

 The focusing of the image on the white screen 6 is performed by moving the projection lens 5 together with the lens holder 10 in the optical axis direction as shown by the arrow.

 Now, the maximum number of pixels of the video generating laminate 2 is, for example, 120 × 24 × 1346 as shown by the broken line in FIG. 7, and the video signal from the video playback device 1 If it corresponds to the number 0 = 1 0 1 0 x 1 3 4 6, it emits light at full size (image is generated).

 If the video signal from the video playback device 1 is less than the maximum number of pixels, for example, 600 × 800, the pixel control unit 8 does not emit light from all pixels, and Only the 600 X horizontal 800 pixels emit light.

Therefore, a window frame 7 is formed around the Q = 600 × 800 pixels, and thus an image of 600 × 800 pixels is projected on the white screen 6. For the sake of simplicity, the brightness on the white screen 6 is set to the maximum white light. Is assumed to be luminance 1.0, and the area without projection light (dark area) is assumed to be 0.0.

 Here, the fact that the light of the light source lamp 4 causes a diffraction phenomenon will be described. For the sake of simplicity, it is assumed that the video signal reproduced by the video reproducing device 1 is also a white video.

 In FIG. 8, a projection lens 5 is mounted on a box of a video image project by a lens holder 10, and the lens holder 10 is screwed into this box (not shown). By screwing or returning the lens holder 110, the projection lens 5 moves in parallel in the optical axis direction, and the focus of the image on the white screen 6 can be adjusted.

 A light blocking plate 11 is arranged on the outer end face of the lens holder 10 in parallel with the projection lens 5 and the white screen 6. The light blocking plate 11 is constituted by a substantially perfect black plate, and completely blocks the lower (right) end, which is a part of the image light L projected from the projection lens 5.

 The light passing through the tip P of the light blocking plate 11 passes through the optical path 14 and forms an image on the white screen 6. Since the light is originally blocked below the optical path 14, it is desirable that the brightness be zero. However, since the image light L is combined with the light from the light source lamp 4, a diffraction phenomenon occurs, and the light behind the P is generated. Wrap around.

 As a result, light that is weaker than the optical path 14 is generated in the optical paths 12, 13, and 15 (these are representative examples and actually exist in large numbers).

 These optical paths 12, 13, and 15 travel as if they originated from point P, and due to the distance difference between optical paths 12 and 13, fringe images 17 and 18 were formed on white screen 6, respectively. tie. When viewed from the front of the white screen 6, as schematically shown on the right side of FIG. 8, these fringe images 17 and 18 appear as light and dark fringes that gradually darken downward (right) (see FIG. 8). In Fig. 8, dark areas are indicated by a large number of diagonal lines.

A luminance graph is shown further to the right of FIG. 8, where the luminous intensity is high and constant at a portion where the light blocking plate 11 is not interposed, and the light path 12 on the lower side (right) outside the light path 14 is light. Luminance irregularities appear on the white screen 6 (projection surface) projected by the road 13.

 Here, the two fringe images 17 and 18 have been described. However, in practice, a plurality of bright and dark fringes whose luminance sequentially decreases from one light source lamp 4 to the optical paths 12 and 13 are generated.

 By the way, such video image projects have become very popular in recent years, and are frequently used for various explanations and guidance in conference rooms, classrooms, and event venues. On the other hand, with the advent of the multi-screen movie of En-Yu-Timment, the necessity of a video software with high amusement property is increasing due to the multi-projection system by this video image project.

 In addition, for various simulation images, CGs that were processed using a combination video system for more realism were projected using a video image projector, as well as a flat screen, as well as a multi-projection system such as a cylindrical screen, a parabolic screen, and a spherical screen. Has become mainstream.

 In general, when performing large-screen projection of television, there is a method of performing high-brightness large-screen projection with a single unit, but it is considerably expensive.

 There is also a method of using a fisheye lens when projecting onto a dome-type screen or the like, but there is a disadvantage that the image quality deteriorates.

 For this reason, a method of creating a large screen by dividing and projecting a plurality of screens has been used. However, in the case of a so-called multi-screen (screen) in which a plurality of video image projectors simply project, a boundary is generally formed between adjacent screens.

 This boundary line is of course annoying, and methods to eliminate this boundary line are actually being implemented. In this method, the screens overlap each other (overlapping), and the brightness of the overlapping projection is doubled. However, the brightness of the border between the screens is adjusted by adjusting the brightness There is a method of cross-over “plending” each other to achieve even brightness.

The projection method by the blending is roughly classified into the following two methods. The above-mentioned optical processing method combines the adjacent images over the entire image by shadowing the defocus part (the part close to the lens) of the light beam (light flux) emitted from the lens surface of the image projection device with an enemy shield. In addition, there are a method of blending, a method of signal processing, and a method of controlling an input signal to a video projector by using a blending waveform so that an adjacent image and the luminance balance are equalized.

 In the above-mentioned optical-type rendering method, it is possible to adjust the range from “black” to “white” to block the light beam.

 Of the latter signal processing methods, the CRT method uses CRT white light emission and can be controlled by signal processing from “black signal” to “white signal”. The following describes the conventional optical blending method in which two video image projects are used on a flat screen for simplicity.

 In Fig. 9, images are projected on a double-size screen 16 with two video image projects 55, 60.

 One (upper) video image projector 55 projects the left landscape in the horizontal direction, and the other (lower) video image projector 60 projects the right landscape. The video signal input to each video image projector 55, 60 is the same as the left video of the right video image projector 60 in the left video image projector 55. Similarly, in the right video image project 60, a significant portion of the left end contains the same portion as the right end image of the left video image projector 55.

 To connect the left and right images continuously on the double screen 16, project the images on the screen 16 from the left and right video image projectors 1, 5, 6, so that the same left and right images can be observed. Adjust the mutual position of the video image project 55, 60 so that they just overlap with.

In other words, if the same part does not look double, a wide image is observed as a continuous image, and the viewer recognizes it as a natural image. Thus the superimposing the left and right video O video projector evening one image is referred to as a-plane loading ₍ In this way, the overlap of the images is almost completely matched.

 However, even if the images match, the image light L-1 and L-2 from both video image projectors 55, 60 are projected on the T portion on the screen 16. Therefore, when considering white light, the brightness of this T region is 2D, which is twice as large as that of the overlapping portion, where D is the brightness of the non-overlapping portion.

 In order to make the dazzling brightness 2D of the T part the same D as the non-overlapping part, place the light blocking plate 11 in the lens holder 10 of the left (top) video image projector as shown in Fig. 8 .

 Since the same part of the image light is blocked, the left and right images will be natural images, and the brightness can be expected to be normal.

 However, as described in FIGS. 8 and 9, several shadow bars and fringe images are generated at the blending boundary.

 Therefore, the following methods are used to make the dazzling luminance 2D of the T portion the same as that of the non-overlapping portion without causing a stripe pattern.

 The light-blocking plate 11 in FIG. 9 is removed (it will be described without omitting it in the drawing), and a blending device 30 is provided between the video reproduction device 1 and the pixel control unit 8, and the left and right videos are provided. In some projectors, the brightness of the output of the overlapping video section by the video projector 55, 60 is adjusted so that the brightness of the T section is the same and a continuous continuous natural screen appears.

 However, in the case of a so-called multi-screen (screen) in which a plurality of images are projected, it is general that a boundary line is formed between adjacent screens.

When the blending method using the optical method is performed to eliminate the boundary line, striped patterns 17 and 18 by the light blocking plate 11 appear as described in FIGS. It is not enough as a video for simulation that requires extraordinary shadowing and high accuracy due to the generation of extraneous shadows. (Among signal processing methods, the latest projectors are liquid crystal instead of white light emission. Since the projection is performed with the equal transmitted light and reflected light, the control by the signal is such that the light tends to leak in the “black signal area” and only the “black signal area”. That is, there is a disadvantage that the resin is lifted without being blended. In addition, video projectors tend to use single lenses, and there is a problem with optical processing (R, G, B optical synthesis) inside the projector using single lenses. A curve cannot be obtained (that is, a single-lens image projection device has a drawback in that, when a light beam is blocked, a plurality of uneven lines are generated).

 Further, the high-precision blending device 30 shown in FIG. 9 is very expensive because electronic control is complicated and precision is required.

 For example, if the price of a video image projector is 250,000 yen, it will be 100,000 to 100,000 times that of 250,000 to 250,000 yen, so it was not easy to use.

 SUMMARY OF THE INVENTION An object of the present invention is to provide a low-cost, simple and easy method for eliminating a stripe pattern generated by multi-screen projection.

[Disclosure of the Invention]

 The present invention has been made to solve the above-described problems, and each image is projected on a plurality of screens using a plurality of projection-type image devices, and a wide image is created by connecting the ends of each image to each other. A light shielding plate disposed in front of a projection lens of an image generation unit provided in the projection-type imaging device, for shielding an end of the projection light and adjusting the brightness of the connection unit, The light shielding plate was composed of a filter whose transmittance gradually decreased from the central part to the peripheral part of the projected light.

 Further, the present invention is configured such that the transmittance of the filter gradually decreases gradually.

 Further, the present invention is configured such that the transmittance of the filter is gradually reduced continuously.

Further, in the present invention, the shape of the fill is adjusted to the shape of the curved screen so that the ends of the images can be continuously joined. [Brief description of drawings]

 FIG. 1 is a diagram showing an overall configuration in which two projection type image devices are provided with a density gradient light shielding plate according to the present invention, respectively. FIG. 2 is a concentration gradient light shielding plate according to an embodiment of the present invention. FIG. 3 is a diagram for explaining the optical function of the concentration gradient light shielding plate according to the embodiment of the present invention, and FIG. 4 is another embodiment of the present invention having a different concentration gradient. FIG. 5 is a diagram illustrating a concentration gradient light shielding plate according to an embodiment of the present invention. FIG. 5 is a diagram for explaining an effect when the concentration gradient light shielding plate according to the embodiment of the present invention is used. FIG. FIG. 7 is a view showing the structure of a concentration gradient shielding plate according to another embodiment of the present invention, FIG. 7 is a view for explaining projection of an image on a screen by a general projection type video apparatus, and FIG. Figure 9 explains the optical function of the plate. It is a figure which shows the whole structure each attached.

[Best Mode for Carrying Out the Invention]

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

 FIG. 1 shows an overall configuration in which a transmission type density gradient shielding plate of the present invention is attached to two projection type video devices (video video projectors). The projection type video devices 55, 60 are placed on the screen 16 composed of a plurality of screens, and are installed so that adjacent comrades overlap each other.

 Projection type imaging devices 55, 60 Each of the lens holders 10 and the defocus line between the lens 5 and the screen 16 on the defocus line physically fills these optical paths. Are provided. The fill-shaped shielding plate is the concentration gradient shielding plate 21 of the present invention.

 FIG. 2 is a view of the lens holder 10 and the concentration gradient blocking plate 21 as viewed from the direction of arrow A in the figure, and the right view of FIG. 2 is an enlarged view of a circle in the left view.

The density gradient blocking plate 21 is constituted by a plurality of filters each having a predetermined width in which light transmittance changes stepwise from an opaque region to a transmissive region, which are sequentially adjacent to each other. The structure is such that the width of the transmission band filter can be set and changed arbitrarily.

 The concentration gradient cutoff plate 21 is a kind of neutral wavelength filter, and has a white light transmittance stepwise from, for example, the vicinity of the optical axis, and a transmission density (D) of 0.15 to 0.30, 1. 2. Finally, it is a gray-scale filter that changes to an opaque plate and changes gradually from white to gray and then to black.

 That is, a band filter 50 of D = 0.15, a band filter 51 of D = 0.30, a band filter 52 of D = l.2, and an opaque wide band filter 53 are formed by connecting the ends to each other. ing.

 The widths of the band filters 50, 51, and 52 are substantially the same, and the length (width) is experimentally determined according to the distance between the video image projector 1 and the white screen 6.

 Now, referring to FIG. 1, a description will be given of the projection in a case where the concentration gradient blocking plates 21 and 22 are attached to the lens holders 10 of two video image projectors 55 and 60, respectively.

 First, referring to FIG. 3, the first video image projector 55 will be described. When a white light is projected, a large rectangular white image is projected on the screen 16.

 Next, when this density gradient cutoff plate 21 is set at the lower (right) end of the lens holder 110 of the video image projector 55, the light projected from the lower (right) end is

 The light that has passed through Obi Fill Yuichi 50 is absorbed by D = 0.15 minutes,

 The light that passed through Obiichi Yuichi 51 was absorbed by D = 0.30 minutes,

 The light transmitted through the band filter 52 is absorbed by D = 1.20 minutes,

 The band filter 53 blocks all light.

Therefore, as shown on the right side of FIG. 3, the brightness on the screen 16 is white with a brightness of 1.0 inside the window, and then the brightness of White, luminance in the part of light transmitted through the band filter 51 The white part of 0.70 and the light transmitted through the band-pass filter 52 gradually decreases in luminance to white of 0.01 luminance, and finally becomes a part without light.

 The luminous intensity on this screen 16 (in the figure, the number of diagonal lines decreases as the brightness increases and the number of diagonal lines decreases, and the number of diagonal lines increases as the brightness decreases) is measured on the line R toward the end. As shown in the figure, there is a step-like line graph (curve) descending to the right.

 Next, when a similar density gradient blocking plate 22 is installed at the upper (left) end also on the front of the lens holder 10 of the lower video image projector 60 in FIG. 1, the light is projected from the upper (left) end. It can be seen that the light has a brightness with a tilt in the reverse direction of FIG.

 A video image project equipped with these two density gradient cutoff plates 21 and 22 The brightness of the projected images from the evening 55 and 60 overlapped as shown by the dotted line on the right side of Fig. 1. In the part, one is down-sloping to the right and the other is down-sloping to the left, so the sum of these luminances is exactly 1.0, and the luminance of the connection is the same white as the luminance 1.0 inside both windows. .

 Therefore, a boundary between a plurality of screens can be formed into a continuous screen image without continuous seams.

 Next, the concentration gradient cut-off plate 21 can be used as the concentration gradient cut-off plate 22 composed of a continuous gray scale.

 As shown in FIG. 4, in the density gradient blocking plate 23, a density graph for reference is shown above, and the transmission density in the width direction from 0.10 (approximately) to 0.30, etc., from the left end to the right end The concentration has been continuously changed to 1.9 mag. The height (length) of the density gradient blocking plate 23 is slightly larger than the diameter of the lens holder 10, and the width is set slightly wider in the gradient direction of the density than the overlap of each image generating laminate 2.

 The structure of the concentration gradient blocking plate 23 is a filter in which the light transmittance changes continuously from a transmission region to a non-transmission region, and the width of the region can be set arbitrarily.

The narrower the width, the larger the concentration gradient and the wider the width. The lower the concentration gradient, the lower the concentration.

 Two video image projects equipped with such a density gradient cutoff plate 23 The brightness of the projected image from the evening as shown by the dotted line in FIG. Since the lower part is the lower part and the other part is a continuous lower part, the luminance obtained by adding these becomes exactly 1.0, and the luminance of the connection becomes the same white as the luminance 1.0 inside both windows.

 Similarly, a boundary between multiple screens can be converted into a continuous screen image without continuous seams.

 In FIG. 1, the screen is further screen-lifted in the upper (lower) direction of the screen 16, and a third video image projector is added in the upper (lower) direction of the video image projector 55 (60). Attach the density gradient cutoff plate 2 1 (2 2, 2 3) to the lens holder of the video projector 1 5 and the 3rd video video projector so that the boundary of the screen is blended to enlarge the video screen rapidly. be able to.

 Density gradient blocking plates 21 (22, 23) will be attached to both sides of the lens holder 110 of the video image project 55 sandwiched between them.

 In FIG. 1, the concentration gradient blocking plate 21 and the concentration gradient blocking plate 22 have been described as blending the flat screen 16, but the screen may be vertical or inclined.

 In addition, the screen can be used with any curved surface such as a cylinder, sphere, paraboloid, or hyperboloid. Constitute.

 For example, inside the spherical surface, the concentration gradient blocking plate 24 is formed in a crescent shape as shown in FIG. 6, and an arc-shaped neutral filter having a constant curvature is connected. The filter is manufactured such that the transmission density (D) of each filter changes from 0.15 to 0.30, 1.2, and finally to an opaque plate from the side closer to the optical axis.

Therefore, even blending between opposing images on the screen And eliminates the problems associated with blending LCDs and the latest projectors.

 Further, in any of the above-described density gradient blocking plates 21, 22, 23, and 24, the combined image area T of the screen and the screen has a density filter corresponding to the emission luminance curve (a) of the video projector. By designing in the evening, smooth blending can be obtained.

[Industrial applicability]

 The structure of the concentration gradient cut-off plate can be made to suit the individual case, such as vertical blending in the vertical direction, horizontal blending in the horizontal direction, and slanting or curved blending. Therefore, it is possible to perform the rendering according to the shape of the projection screen such as flat, dome, hemisphere, and circle. When projecting onto a spherical or dome-shaped screen, a split projection method using multiple screens is adopted. However, according to the present application, it is a useful means of obtaining continuous images with high image quality.

Claims

The scope of the claims 1. Each of the images is projected onto a plurality of screens using a plurality of projection-type image devices, and ends of the images are connected to each other to create a wide image. A light shielding plate disposed in front of a light projection lens of an image generation unit provided in the light shielding plate to shield an end of the projection light and adjust the brightness of the connecting portion; A light shielding plate for a projection-type video device, comprising a filter having a transmittance that gradually lowers over a portion.  2. The light-shielding plate of a projection-type image apparatus according to claim 1, wherein the transmittance of the filter is configured to gradually decrease.  3. The light shielding plate of a projection type video device according to claim 2, wherein the transmittance of the filter is continuously and gradually reduced.  4. The projection-type imaging device according to claim 1, wherein the shape of the fill screen has a structure in which ends of respective images are continuously joined according to a shape of a curved screen. Light shielding plate.