JPH0351155B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image projecting device, in which a plurality of sets of inline or delta-arranged projectors are arranged in a different order for each set, so that the image can be projected regardless of the position of the viewer. An object of the present invention is to provide an image projection device capable of obtaining a color image with bright image brightness without any hue change.

2. Description of the Related Art Conventionally, there has been an image projection device that obtains a color image by enlarging and projecting a red image, a green image, and a blue image onto one screen. This conventional image projection device has three projectors that project red, green, and blue images, respectively, as shown in Figure 1 because it simplifies the convergence of matching the three images at one point on the screen. They are arranged inline on a horizontal plane. In the figure, 1 is a projector for a green image, which is placed on the normal line passing through the center point O of the screen 2, and a projector 3 for a blue image and a projector 4 for a red image are angled horizontally to the projector 1, respectively. They are arranged at an opening angle of θ ₁ . The screen 2 transmits and scatters the incident light from the projectors 1, 3, and 4, but in order to ensure the brightness of the screen image, the intensity of the scattered light on the screen 2 has a sharp directivity that matches the direction of the incident optical axis. It is made to have.
Therefore, at point P on the screen 2, for example, the directivity of the blue light from the projector 3 is as shown by the solid line, and the directivity of the red light from the projector 4 is as shown by the broken line. Therefore, when the observer's eyes are at point Q, the intensity of the blue light at point Q is the length of the line segment PR defined by the intersections P and R of the straight line PQ connecting points P and Q and the solid line. The intensity of the red light is expressed by the length of the line segment PS defined by the intersections P and S of the straight line PQ and the broken line. This line segment PR,
The difference in length of PS is the difference in intensity between blue light and red light, and in this case, point P on screen 2 appears blue, so when the position of the observer's eyes moves, the image on screen 2 The problem was that the color changed and the color looked unnatural. Another drawback was that the brightness of the image projected onto the screen 2 was lower than that of a color television.

The present invention eliminates the above-mentioned drawbacks, and each embodiment thereof will be described with reference to FIG. 2 and subsequent figures.

FIG. 2 is a perspective view of one embodiment of the image projection apparatus according to the present invention, and FIG. 3 is a front view as seen from the screen side. In FIG. 2, the same parts as in FIG. 1 are given the same reference numerals. In Fig. 2, numerals 1 and 5 are both projectors for green images, and they are arranged at an angle of θ ₂ in the direction perpendicular to the normal line passing through the center point O of the screen 2, indicated by a chain line. . Furthermore, a projector 3 for a blue image and a projector 4 for a red image are arranged horizontally with respect to the projector 1 at an opening angle of θ ₁ (θ ₁ is, for example, 5 to 7 degrees), and the projector 4 for a red image is A projector 6 and a blue image projector 7 are arranged horizontally with respect to the projector 5 at an angle of θ ₁ . When these projectors 1, 3 to 7 are viewed from the screen 2 side, as shown in Figure 3, the first set of projectors 1, 3, and 4 project blue images to the right with green image projector 1 in the center. The projector 3 has a red image projector 4 on the left, and the second set of projectors 5, 6, and 7 have a green image projector in the center, a red image projector 6 on the right, and a blue image projector on the left. Machine 7 is located.

These projectors 1, 3 to 7 are each, for example, a fourth projector.
The structure is as shown in Figure A or B. In FIG. 4A, an image drawn by emitting light by irradiating the phosphor-coated surface 9 in the vacuum tube 8 with an electron beam is reflected and magnified by the concave mirror 10 in the vacuum tube 8, and the Schmitt lens 1
After aberrations such as spherical aberration are corrected in step 1, the image is projected onto a screen 2. In addition, in FIG. 4B, the emission image of the phosphor of the cathode ray tube CRT12 is shown by the convex lens 1.
3 and is enlarged and projected onto screen 2.

The screen 2 is of a transmission type, and is made of polymethyl methacrylate (PMMA) resin, for example, and has no difference in transmittance in the wavelength range of visible light, and has fairly strong directivity in the direction of the incident optical axis.

Now, considering the blue image, at point P on the screen 2 shown in FIG. 5, the directivity of the blue light from the projector 3 is shown by the solid line, and the directivity of the blue light from the projector 7 is shown by the broken line Thus, the total amount of blue light is added as shown by the dashed line. Furthermore, if the projectors 3 and 7 in FIG. 5 are replaced with projectors 6 and 4, the directivity of the entire red light at point P will also become as shown by the dashed-dotted line.
Therefore, when the observer's eye position is at point Q,
The intensity of blue light and red light at point Q is the straight line PQ
It is expressed by the length of the line segment PT defined by the intersection points P and T between the line and the dashed-dotted line. Therefore, no difference in intensity occurs between blue and red, and the image on the screen 2 does not change in hue due to movement of the observer's eye position. Regarding blue and green or red and green, since the angle between these projectors is small, there is no noticeable change in hue compared to the conventional technology, and there is no problem with the device of the present invention.
In addition, the intensity of both blue light and red light is the line segment PR,
Since the length of PS is expressed by the length of the line segment PT added, and the same can be said for green light,
The image brightness of the screen 2 is approximately twice that of the conventional one.
In addition, since this image brightness becomes sufficiently large, the directivity of the screen 2 is changed from the elliptical shape shown in Figures 1 and 5 to a semicircular shape, which further reduces the difference in intensity between each color. The resolution of the image on the screen 2 can be improved by increasing the F-number of the optical system such as the concave mirror 10 and convex lens 13 shown in FIGS. 4A and 4B.

The projectors 1, 3 to 7 may be arranged in a delta arrangement, as shown in FIG. 6A, so that the center of each projector forms an equilateral triangle or an erect isosceles triangle.
At this time as well, the projectors 3 and 5 for blue images are positioned to the right and left of the projectors 1 and 5 for green images, respectively.
In this case as well, the same effects as in the above embodiment can be obtained.

Furthermore, a projector 14 for green, red, and blue images;
15 and 16 as a third set and arranged as shown in FIG. 6B, an image with even brighter image brightness can be obtained.

In each of the above embodiments, the screen is of a transmissive type, but the screen may be of a reflective type, and is not limited to the above embodiments.

As described above, the image projection device according to the present invention can produce red images, green images,
It consists of multiple sets of projectors, each set of three projectors projecting a blue picture, and each set has a different arrangement order of the projectors that project a red picture, a green picture, and a blue picture, making it difficult for the observer to There is no difference in the intensity of each color no matter where the eye position is, the image does not change in hue even if the eye position moves, and the brightness of the image on the screen is bright. This has the advantage that it can purify the color, eliminate the difference in intensity between the colors, and improve the resolution of the image.

[Brief explanation of drawings]

Fig. 1 is a diagram for explaining the directivity on the screen of a conventional image projection device, Fig. 2 is a perspective view of one embodiment of the device of the present invention, and Fig. 3 is a view of the device shown in Fig. 2 from the screen side. Front view of the projector, No. 4
Figures A and B are diagrams for explaining the projector used in the device shown in the second diagram, Figure 5 is a diagram for explaining the directivity on the screen of the device of the present invention, and Figures 6A and B are diagrams for explaining the projector used in the device shown in the second diagram. It is a front view of the projector seen from the screen side of the modified example of the invention device. 1, 3-7, 14-15...Projector, 2...Screen, 8...Vacuum tube, 9...Phosphor coated surface,
10... Concave mirror, 11... Schmitt lens, 1
2...Cathode ray tube, 13...Convex lens.

Claims (1)

[Claims] 1. In an image projection device that projects a red image, a green image, and a blue image onto a screen to synthesize a color image, the red image arranged in-line or in delta,
Three projectors projecting green and blue images respectively.
1. An image projection apparatus comprising a plurality of sets of projectors, each of which projects a red image, a green image, and a blue image in a different order of arrangement.