JPS604450B2 - stereoscopic image projection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention projects a slide film or 8 mm film or the like on which a normal two-dimensional image is recorded onto a screen.
This invention relates to a stereoscopic image projection device for observing this as a stereoscopic image.

Conventionally known stereo projection techniques take measures to record stereoscopic information in some sense at the image recording stage. For example, integrated lenticular
Photography and holograms are good examples. In other words, techniques for reproducing images having stereoscopic information on a screen have been conventionally known. On the other hand, stereo movies that use polarized glasses or dichroic glasses and take advantage of the binocular parallax of the human eye are also known, but in this case, two images, a left eye image and a right eye image, must be used. Must be. The main purpose of the stereoscopic image projector of the present invention is to project a film image taken with a normal image pickup device, such as an 8 mm camera, onto a screen without taking any special measures such as including stereoscopic information, and to display the film in a stereoscopic manner. An object of the present invention is to provide an extremely inexpensive and simple three-dimensional image projection device for the purpose of

The feature of the stereoscopic image projection device of the present invention is that it skillfully utilizes the psychological effect of the binocular parallax of the naked eye. (good quality) and polarized glasses. The stereoscopic image projection device of the present invention is a kind of lens attachment consisting of two optical towers and a polarizing film,
An advantage of the present invention is that it can be installed anywhere in front of the projection lens of a slide projector or 8 mm projector, or in the space between the lens and the film, and is extremely easy to attach and detach. The stereoscopic sensation obtained by the device of the present invention is
This is an artificially created three-dimensional sensation because images recorded on film do not have essential three-dimensional information. In other words, it cannot be denied that this is a false three-dimensional image. However, when photographing a subject normally, there is a high probability that the D portion in the angle of view will be configured as a foreground, and the peripheral portion will be configured as a distant view. The three-dimensional image projection device of the present invention is effective for such compositions. Another advantage of the present invention is that by adjusting the forehead angle of the optical sliding door, the stereoscopic image projected on the screen can be adjusted, and the stereoscopic sensation that the viewer can perceive is better than when viewing the actual subject with the naked eye. The scales are even more exaggerated.

A third advantage of the present invention is that by changing the angles of the two optical butterflies with respect to the optical axis, the projected image can be expanded or compressed in the left-right direction, and either one can be selected.

Such nonlinear effects are expected to modulate artificial stereoscopic sensation. A fourth advantage of the present invention is that the stereoscopic effect or perspective of the projected scene can be freely adjusted by inserting a correction plate that corrects the image shifting effect of the optical nucleus.

In other words, by adjusting the angle of the correction plate, it is possible to make the projected image appear closer to or farther away from the actual screen. Embodiments of the stereoscopic image projection apparatus of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram schematically showing a conventionally known method of projecting a pseudo-stereoscopic image. Film 3 installed on the right side of optical axis x X'
The upper image size is the images a and q shown on the stereo screen 7.
projected as. The film 3 is illuminated by an illumination lamp 1 and a condenser lens 2, and an image aobo is projected onto a screen 7 via a projection lens 4. A conventionally known three-dimensional image projection device consists of optical butterflies 6r, 61 and polarizing films 5r, 51 adhered thereto. Here, the tail symbols r and 1 indicate that they contribute to the image configuration for the right eye and the left eye, respectively. If this 3D image projection device is removed, the image heat BO
merely images ordinary two-dimensional traces a, b, on the screen 7. The optical lenses 6r and 61 are installed so as to divide the lens aperture into left and right halves, and the polarizing films have mutually orthogonal polarization directions of 145o and 145o, as shown by the arrows in FIG. Due to the action of the optical towers 6r and 61, the images of the image object bo are laterally shifted from each other on the screen 7, and the images are respectively a
rbr, alb, etc. That is, arbr, alb
, are right eye images and left eye images whose polarization directions are orthogonal to each other. This is observed with the naked eyes 9r, 91 through polarized glasses 8r, 81. The polarization direction of the polarized glasses 8r and 81 is determined by the polarizing film 5r.
, 51, respectively. In this case, it is ideal that the right eye image and left eye image generated on the screen 7 have the same degree of parallax as when observing the subject from a predetermined distance, but in reality, the sliding angle of the optical device must be adjusted considerably. Even if it is made larger, only a slight inkstone difference as shown in Fig. S will occur. FIG. 5 shows a cut-out square pyramid viewed from directly above as an example of a subject.

FIG. 6 shows the left eye image when the projection lens focal length is 72 with an optical angle of 5o and a screen distance of 2.
D, is slightly elongated, and only a small amount of left eye disparity occurs.

FIG. 7 is a left eye image obtained by the stereoscopic image projector according to the present invention, as will be described later, and shows a left eye image with a large parallax in which the side C2D2 is significantly elongated.

That is, with the arrangement of the optical pincers 6r and 61 as shown in FIG. 1, an image having the desired parallax cannot be obtained even if the sliding angle is made considerably large. Note that the results shown in FIGS. 6 and 7 can be easily confirmed by simple geometric optical calculations and experiments. Furthermore, in the conventional method, since the optical converter divides the lens aperture into left and right halves, light rays are kicked in the left and right directions of the image filter, making it impossible to obtain a homogeneous binocular image. The present invention eliminates these two drawbacks and changes the arrangement of the optical elements so as to produce the desired binocular parallax, and this point is a feature and advantage of the present invention.
FIG. 3 shows an embodiment of the stereoscopic image projection apparatus of the present invention.

One surface of the optical sliding door 6r, 61 to which the polarizing films 5r, 51 are bonded is tilted in opposite directions to the optical axis by an angle B. Figure 3 shows this optical system viewed from directly above, with optical ports 6r and 61'
As shown in Fig. 4 (Fig. 4 is a view of the optical butterfly seen from the optical axis direction), unlike Fig. 2, the lens opening □ is divided into upper and lower halves, so both eyes can There is no unevenness in the amount of light in the horizontal direction of the image. In addition, as shown by the arrow in FIG. 4, the polarizing film 5r
, 51 are installed so that their polarization planes are perpendicular to each other.

In this case, it is shown in FIG. 7 that the stereoscopic parallax of the projected image becomes significantly larger than that of the conventionally known stereoscopic image projector. Figure 7 depicts the left eye image C2D2E2F2 based on calculated values and experiments when the head angle of the tower is 8 = 30o (the specifications of the projection lens are the same as in Figure 6). 5), the image has a large parallax with the side C2D2 extending to the left. Shokoro 6r
, 61 can finely adjust the angle 8 around the respective rotation axes Gr, G, but the adjustment mechanism can be easily realized by a conventionally known mechanism, so a detailed explanation thereof will be omitted. . By doing so, it is possible to adjust the binocular parallax and observe the projected image while exaggerating the stereoscopic sensation generated by the actual subject. In FIG. 3, the optical lenses 6r and 61 are arranged so that their apex portions are close to the projection lens 4. For this reason, both the left eye image and the right eye image take the form of being expanded in the left-right direction, but these images can also be compressed left and right. As shown in FIG. 8, if the apex of the optical device is placed away from the lens 4, the square pyramid C3D3E shown in FIG.
A horizontally compressed left eye image (or right eye image) with a large parallax such as 3F3 can be obtained, and this can be shown in a drawing by simple optical calculation. The left and right eye images compressed in the left-right direction are closer to actual stereoscopic vision with the naked eye. The problem here is the lateral movement of the left and right eye images. It can be confirmed by optical calculation that the magnitude of this movement increases as the sliding door angle y, the thickness t of the sliding door glass, and the forehead angle 8 increase. However, in the embodiments of FIGS. 3 and 8, the amount of lateral movement of the left eye image and the right eye image is in the left and right directions, respectively, regardless of the orientation of the sliding door. That is, since the shift of both numbers is in the direction of increasing the distance between the eyeballs, it is inconvenient for observing the projected image. Therefore, this stereoscopic image projector should be designed in consideration of the specifications of the optical acid so that the amount of shift of both images is equal to or less than the distance between the eyes. FIG. 10 shows an example of a method for correcting this image movement amount.

This figure shows only the correction of the left eye image, and the right eye image is not shown. If a correction plate 101 made of, for example, parallel plane glass is installed in front of the optical sliding door 61 at an angle of 8,
The left eye images a and bl before insertion are moved to the right as a,'b,' due to the light beam deflection effect of this correction plate, and b, = b. ′
There is something to be done. The amount of light ray movement by this correction plate can be easily calculated from the plate thickness t, head angle 0, and glass refractive index n. There is no problem in principle if the thickness of the optical plate 61 is increased instead of using this correction plate 101, but the optical plate 61
8 is used as a means for generating an inkstone difference, which is its original purpose, and has a structure that can also adjust parallax. Therefore, it is practically preferable to install it separately for lateral movement correction and to make 8 variable. FIG. 11 shows another embodiment of the stereoscopic image projection apparatus according to the present invention. optical tower 6r with polarizing films 5r and 51 bonded;
Reference numeral 61 is located between the projection lens 4 and the film 3, and is installed at a position as close to the lens as possible. In this case, optical sliding doors 6r, 6
It must be noted that the angle B of No. 1 should be installed in the opposite direction to that shown in FIG. Further, as described above, the optical sliding doors 6r and 61 should divide the opening □ into upper and lower halves.
The advantage of this method compared to the embodiment shown in FIG. 3 is that the amount of lateral movement mentioned above is reduced, and this can be determined by simple optical calculations. Another disadvantage is that since the optical system is installed inside the lens, the aberration of the projected image is large and it is difficult to obtain a clear image. In order to solve this problem, the thickness of the optical sliding door should be made thinner and the sliding sliding angle y should be made smaller.
In this case as well, a mechanism for adjusting the optical angle can be easily provided. It is obvious that in order to obtain a binocular parallax image that is expanded and compressed laterally as described above, it is sufficient to reverse the positional relationship of the apex corner of the optical cone with respect to the projection lens. In this way, firstly, the binocular parallax can be increased and the parallax can be adjusted, and secondly, it is possible to provide a stereoscopic imaging device with no unevenness in the amount of light between the left and right images as an inexpensive, small and lightweight lens attachment. Therefore, it is possible to create a pseudo-stereoscopic view of 8mm film or slide positives made by normal photographing methods, and it can be easily attached to an existing film projection device. It can be expected to have a wide range of applications such as entertainment, educational projection equipment, and medical biological observation.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing a conventionally known stereoscopic image projector. Figure 2 is a diagram of the optical sliding door viewed from the optical axis direction. FIG. 3 is a diagram showing an embodiment of the stereoscopic image projection device of the present invention. Figure 4 is a diagram of the optician shown in Figure 3 viewed from the optical axis in all directions. Figure 5 is an example of a subject. FIG. 6 shows only the left eye image among the projected images obtained by the conventional stereoscopic image projector shown in FIG. FIG. 7 is a left eye image extended in the left-right direction by the stereoscopic image projector of the present invention. FIG. 8 is a diagram showing the optical orientation for obtaining a projection image compressed in the left-right direction. Figure 9 is an image of the left eye compressed in the left-right direction. FIG. 10 is a diagram showing the arrangement of a correction plate for correcting the amount of lateral movement of the left eye image. FIG. 11 shows another embodiment of the stereoscopic image projection apparatus of the present invention. 1: Lighting lamp, 2
: Condenser lens, 3: Film, 4: Projection lens,
5r, 51: Polarizing film, 6r, 61: Optical filter 7: Stereo screen, XX': Optical axis, a. : Image on film 3, a, b, : Projection image on screen 7, arbr: Right eye image, a, bl: Left eye image, 8r, 81
: polarized glasses, 9r, 91: naked eye, GI, Gr: center of rotation of optical axis, 8: tilt angle of optical acid, CDEF, C, D,
E, F,, C2D2E2F2: 4 vertices of a square pyramid, 1
0 1: Correction plate, a, 'bl': Left eye image with the amount of lateral movement corrected. Moxibustion diagram 2nd figure 3rd figure Even 4th figure

Claims (1)

[Claims] 1. A film projection device in which an image on a film surface illuminated by an illumination lamp through a condenser lens is projected onto a screen by a projection lens,
two optical wedges are installed adjacent to the projection lens so as to divide the aperture of the projection lens into upper and lower halves, and these two optical wedges are inclined in mutually opposite directions with respect to the optical axis; A three-dimensional image projection device characterized in that polarizing plates whose polarization directions are perpendicular to each other are adhered to each of the optical wedges. 2. The stereoscopic image projection apparatus according to claim 1, wherein the apex portion of the optical wedge is close to the projection lens, and the optical wedge is installed immediately in front of the projection lens. 3. The stereoscopic image projection apparatus according to claim 1, wherein the apex portion of the optical wedge is located at a position farther from the projection lens, and the optical wedge is installed immediately in front of the projection lens. 4. The stereoscopic image according to claim 1, wherein the apex portion of the optical wedge is close to the projection lens, and the optical wedge is placed on the optical axis between the projection lens and the film. Projection device. 5. The optical wedge according to claim 1, wherein the apex portion of the optical wedge is located at a position farther from the projection lens, and the optical wedge is installed on the optical axis between the projection lens and the film. Stereoscopic image projection device. 6 Claims 1, 2, 3, and 4, characterized in that the inclination angles of the two optical wedges are adjustable.
3. The stereoscopic image projection device according to item 5, item 6, or item 6. 7. Claims 1, 2, and 3, characterized in that a correction plate is provided close to each of the two optical wedges in order to correct lateral movement of the two projected images on the screen. 3. The stereoscopic image projection device according to item 4, item 5, or item 6.