JP2857362B2 - Stereo slide mount and mask amount guide device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereo slide mount and a mask width guide device for the stereo slide mount, and more particularly to a stereo slide mount and a mask width guide device for the stereo slide mount which facilitate the mounting operation. It is about.

[0002]

2. Description of the Related Art FIG. 10 shows left and right photographing screens PL and PR of a stereo camera. The difference between the visual fields of left and right photographing lenses of the stereo camera causes a difference between the left and right ends AB of the left screen PL and the right screen PR. The area between the right ends C and D of the screen is a part that does not overlap between the left and right screens. This non-overlapping part AB, C
In the case of -D, a stereoscopic image is not formed when viewed with a stereo slide viewer, and as shown in FIG. 11, when viewed with both eyes, the edge of the other window overlaps the boundary between the overlapping portion and the non-overlapping portion, and A line will be visible. Therefore, in order to prevent this, the width of the window of the stereo slide mount is formed narrower than the screen size of the slide film, and the non-overlapping portions AB,
It shields CD.

FIG. 12 shows a stereo slide mount 1 made of paper.
The upper half is bent toward the near side at the position of the folding line 2 in the middle of the upper and lower portions, so that the upper surface front cover frame 3 and the lower half rear surface base frame 4 are bonded to each other. Have been. The cover frame 3 and the base frame 4
Windows 5L, 5R, 6L, and 6R are punched on the left and right, respectively, and the windows are arranged vertically symmetrically with the folding line 2 as the axis of symmetry.

[0004] Above and below the windows 6L and 6R of the base frame 4, reference lines 7 and 8, which are targets for the vertical position of the slide film, are printed, and a left slide of a pair of stereo slides cut for each frame. Is aligned with the lower left window 6L, and the edges are bonded. Similarly, the right slide is aligned with the lower right window 6R, and then the cover frame 3 is bent and bonded to the base frame 4.

[0005] When positioning the slide film, using the mounting gauge marks a pitch P ₁ and equal pitch transparent right and left windows of the stereo slide mount 1 in plastic plate or a glass plate, the most foreground of the subject the lateral pitch is performed by equal and positioning pitch P ₁ of the window.

[0006] At this time, in the photograph of distant object as landscape photography equal position of the object in the left and right screen, but the pitch P ₁ of the film pitch and the window is substantially equal adjustments, close photographing distance of an object extent, because the subject on the left and right of the screen by the parallax of the left and right lens approaches, so that equally the film pitch as P ₁ of the pitch of the left and right of the subject window is expanded than the pitch P ₁ of the window. Thus, while shielding the outer non-overlapping portions of the left and right of the screen, such that the inner edges of the left and right of the screen is not exposed in the window, the center pitch P ₁ is the width W of the window in the same window is different to what stage Several types of stereo slide mounts are available, and stereo slide mounts are selected and mounted according to the shooting distance of the subject.

The applicant of the present application has proposed a stereo slide mount formed so that stereo slides are set at a constant pitch. As shown in FIG. 13, the stereo slide mount includes a cover frame 11 and a base frame 12, and the cover frame 11 and the base frame 12 have windows 13L and 1L, respectively.
3R, 14L, and 14R are provided.

At four corners of the windows 14L and 14R of the base frame 12, positioning pins 15 which engage the perforations of the slide film F to be fixed and match the screens of the two slide films with the windows 14L and 14R respectively.
Are provided, and the windows 13L, 1 of the cover frame 11 are provided.
A hole 16 corresponding to the positioning pin 15 is provided around the 3R, and the positioning pin 15 and the hole 16 are fitted to join the base frame 12 and the cover frame 11 together.

This stereo slide mount is compatible with the stereo camera proposed by the present applicant. This stereo camera has the same perforation of the film F and the relative position of the screen on the left and right, and The lens shift mechanism can adjust the center distance between the lenses to take a stereo photograph with parallax optimal for the distance to the subject. Therefore, if the stereo slide photographed by the stereo camera is mounted on the stereo slide mount, the left and right films have a fixed pitch P.
It is fixed at ₂ to obtain the optimal stereo effect, and the loss of the screen is eliminated as much as possible.

[0010]

The stereo slide mount of the fixed film pitch type shown in FIG. 13 eliminates the complexity of the mounting operation in the conventional stereo slide mount and the possibility of erroneously mounting the film pitch. At the time of shooting, it is necessary to adjust the parallax according to the distance to the subject. Therefore, when a stereo slide photographed by a general stereo camera having no lens shift mechanism is mounted on the stereo slide mount of the fixed film pitch, the non-overlapping portions on the left and right screens may be obstructive. is there.

[0011] Therefore, regardless of the presence or absence of a mechanism for adjusting the distance between lenses of a stereo camera, there is no need to adjust the pitch of a stereo slide, so that it can be easily mounted and an accurate three-dimensional effect can be obtained. Therefore, the present invention has an object to solve the above problems.

[0012]

SUMMARY OF THE INVENTION The present invention proposes a camera for achieving the above object, in which a perforation of a perforated film and a pair of left and right photographing screens have the same relative position. A stereo slide mount for mounting a stereo slide photographed in the above, comprising a base frame and a cover frame each having two rectangular windows arranged side by side, and to be fixed to a film mounting surface of the base frame. A positioning pin is provided to engage the perforations of the slide film to match the screens of the two slide films with the windows, and a hole corresponding to the positioning pin is provided on the film holding surface of the cover frame, and the positioning pin and the hole are provided. To join the base frame and cover frame In the slide mount, a plurality of types of cover frames are created in which the width between the left and right windows of the cover frame is the same as the width between the windows of the base frame, and the window width is sequentially reduced with respect to the screen width of the film. Then, the cover frame is selected and joined to the base frame, so that the shielding area on the left and right outer sides of the stereo slide film can be adjusted. A framing mask having a rectangular window in the center and having a locking hole for engaging with a positioning pin of the base frame, wherein a positional relationship between the locking hole and one vertical side of the window is provided. , The window width is the same as the positional relationship between the inside vertical side of the stereo slide film screen and the perforation, and the window width is By creating a plurality of types of framing masks that are sequentially reduced from the width, selecting the framing mask, superimposing the framing mask on a slide film on the base frame, and fitting a cover frame to the base frame, the left and right sides of the stereo slide film are formed. A stereo slide mount characterized in that an outer shielding area can be adjusted, and a stereo slide mount characterized in that a hinge portion is provided at a central portion on the left and right sides of the cover frame to be freely formed. Things.

Further, a transparent film or a transparent glass is attached to each of the windows of the plural types of frames having the same shape as the cover frames having the plural types of window widths, and the same collimation pattern is formed at the same position on the left and right windows. A mask width guide device used for the marked stereo slide mount, and a mask width guide device for the stereo slide mount, wherein the collimation pattern is a pattern including a plurality of vertical lines or a plurality of vertical lines. Is what you do.

A stereo slide viewer having two left and right optical systems including a projection lens, a focusing screen, an erecting prism for inverting an inverted image on the focusing screen, and an eyepiece, wherein the left and right focusing screens are provided. Marking the same collimation pattern at the same position, a projection magnification adjustment mechanism for the image on the reticle, a spacing adjustment mechanism for the reticle, and an interlocking mechanism of the projection magnification adjustment mechanism and the spacing adjustment mechanism are provided, Formed so that the outer edges of the left and right focusing screens and the outer edges of the projection screen are coincident regardless of the projection magnification by the interlocking mechanism,
The mask width guide device of the stereo slide mount in which the relative position between the collimation pattern and the projection screen fluctuates in conjunction with the projection magnification, and the collimation pattern of the reticle has several vertical lines or several vertical lines. An object of the present invention is to provide a mask width guide device for a stereo slide mount, which is characterized by a pattern including lines.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to FIGS. FIG. 1 shows a stereo slide mount according to the first embodiment.
This is the same as the stereo slide mount shown in FIG. The stereo slide mount has a base frame 21 of (a) formed by injection molding of resin, and (b) and (c).
(D), and windows 23L, 23R, 24L, and 24R are provided on the left and right sides, respectively. Left and right windows 23L, 23 of base frame 21
The pitch P ₃ of R is approximately 6 which is close to the pitch of both eyes of a human.
The height is set to about 3.5 mm, and the vertical and horizontal dimensions of the windows 23L and 23R are the same as or slightly larger than the screen dimensions of the slide film F, so that the entire screen of the film F can be seen.

On the base frame 21, cylindrical positioning pins 25 which engage with the perforations of the slide film F are symmetrically erected at four positions on the upper, lower, left and right sides of the window.
A hole 26 is provided in the cover frame 22 at a position symmetric to the positioning pin 25 of the base frame 21.

The positional relationship between the positioning pins 25 of the base frame 21 and the windows 23L and 23R is determined by comparing the perforations of the film F and the screen of the stereo camera configured so that the relative position of the screen is always the same on the left and right. The perforations on the top, bottom, left and right of the slide film F, which are set to the same positional relationship as the perforations, are engaged with the four positioning pins 25, so that the center of the windows 23L and 23R and the slide film F
Screen centers match.

The cover frame 22 is connected to the left and right windows 2.
4L and 24R intervals and the width of the window are
One equal to the window interval C ₁ and the width W _{0 of the} window (# 0)
From interval C ₁ of the window as a plurality of types of progressively stepwise reduced window width W is the same (# 1, # 2, # 3, ‥‥) are prepared (actually per stage The change in the window width is minute, but is exaggerated in FIG. 1). Therefore, the cover frame 22 joined to the base frame 21
The shielding area on the left and right sides of the stereo slide changes stepwise according to the number, and a stereo slide having a shielding area corresponding to the shooting distance of the subject can be created.

Further, a thin hinge portion 22a is formed in the left and right center of the cover frame 22 in the vertical direction, and the cover frame 22 can be bent at the center. FIG.
As shown in the figure, the left film 23 of the stereo slide is mounted on the left window 23L of the base frame 21, the left portion of the cover frame 22 bent at the center is overlapped, and the positioning pins 25 and the holes 26 are fitted. Then, the base frame 21 and the cover frame 22 are joined by mounting the right slide on the right window 23R of the base frame 21 and overlapping and fitting the right portion of the cover frame 22.

When mounting a stereo slide,
By using the mask amount guide device according to claim 4
It is possible to objectively select the optimal cover frame 22
it can. As shown in FIG. 3, the mask amount guide device 31
Are a plurality of types of cover frames 22 (#
0, # 1, # 2, # 3, etc.)
Shaped frame 32 (# 0, # 1, # 2, # 3, ‥‥)
A transparent film 34 is attached to the window 33 of the
The same collimation pattern at the same position on the transparent film 34
35 are printed or developed. Collimation pattern 35
Is the width of the window 33 (W _0,W_1,W_2,W_3,Regardless of ‥‥)
The vertical line passing through the center of the screen and the vertical lines
And complement circular patterns and horizontal lines at the center of the screen.
Auxiliary patterns are added, but the number of vertical lines and auxiliary patterns
The presence or absence of the pattern and its shape are not particularly limited.
No.

These mask amount guide devices 31 (# 0,
# 1, # 2, # 3,... Alone or temporarily fixed to the base frame 21 and viewed with both eyes with a stereo slide viewer, the human visual system The visual axis is adjusted so that the left and right collimation patterns 35 coincide with each other by the collimation effect of, and the image looks as shown in FIG. However, for example, a stereo slide photographing a foreground subject is mounted on the base frame 21, and
When the mask amount guide device 31 is superimposed on the subject and the collimation pattern 35 on the left and right is displaced due to the parallax between the subject and the collimation pattern 35, it looks like FIG. 4B (the illustration of the subject image is omitted). . In such a case, if the mask amount guide device 31 is sequentially changed to one having a larger number,
When a mask amount guide device with an appropriate window width is installed,
The left and right collimation patterns 35 coincide with the object image and look as shown in FIG. 4A, and the sense of distance between the collimation pattern 35 and the object is the same.

If the window width is further changed to a mask amount guide device one step narrower, all the objects appear to be located at the back of the collimation pattern 35, and the stereo slide adjusted at this stage is most easily seen. However, whether the number of the cover frame 22 is set to this stage or the previous stage may be determined according to preference.

When the number of the cover frame 22 is determined, the mask amount guide device 31 is removed from the base frame 21, and the cover frame 22 of the determined number is fitted to the base frame 21, thereby completing the mounting operation.

FIG. 5 shows a framing mask 41 of the stereo slide mount according to the second aspect, which is formed by punching a window out of a light-shielding material such as paper or a black resin film, and has a semicircular shape corresponding to the perforation of the slide film. Notches 41a are provided at four locations, up, down, left, and right. As with the cover frame 22, the framing mask 41 has a plurality of types (# 1, # 2, # 3,...) In which the width of the window changes stepwise.

The relative positions of one vertical side of the window 42 of each framing mask 41 and the semicircular notch 41a are all the same as the positional relationship between the vertical side of the screen of the slide film and the perforation.

When masking the screen with the framing mask 41, the number of the framing mask 41 to be used is determined by the above-described mask amount guide device 31, and as shown in FIG. Framing mask 4 so that the outside of
1 is aligned and superimposed on the slide film F. When the cover frame 22 of # 0 is fitted to the base frame 21, the slide film F and the framing mask 41 are sandwiched in a laminated state. Subsequently, the outside of the right slide film F is similarly shielded by the framing mask 41, and the cover frame 22 is attached to the base frame 2.
1 and a stereo slide mount is assembled.

Naturally, when the framing mask 41 is used, it is sufficient to prepare one type of cover frame 22 (# 0) having the largest window width, and it is not necessary to prepare a plurality of types of cover frames. . FIG. 7 shows another embodiment of the framing mask.
The framing mask 43 is provided with circular holes 44 at four corners as means for engaging with the one positioning pin 25.

FIGS. 8 and 9 show a mask amount guide device 51 according to claim 6, wherein a stereo slide holder 53 and a pair of left and right projection lenses 54 are mounted on a slide guide table 52 as shown in FIG. A pair of left and right reticle holders 57 are attached to a feed screw 56 which is mounted on the front side of the lens holder 55 in the left-right direction. As shown in FIG. 9, a collimation pattern 59 mainly composed of vertical lines is formed on the reticle 58 mounted on the reticle holder 57, as shown in FIG. 9A, similarly to the mask amount guide device 31 (# 0) of FIG. Is provided.

As shown in FIG. 8, an erect prism 60 is fixed to the front end of the slide guide table 52 so as to face the focusing screen holder 57, and an eyepiece 61 is mounted on the erect prism 60. Further, a semicircular reflector 62 is fixed to the rear end of the slide guide table 52, and an illumination bulb 63 is installed in its internal space to uniformly illuminate the back of the stereo slide mount mounted on the stereo slide holder 53. It is configured to do so.

The center of the screen of the stereo slide mount mounted on the stereo slide holder 53 and the left and right optical axes passing through the projection lens 54 and the erecting prism 60 are set to be equal and parallel to the parallax at infinity. The lens holder 55 is slidable in the optical axis direction.

Feed screw 56 for moving reticle holder 57
The left screw is on the left and the right screw is on the right. By rotating the adjustment knob 64 attached to the end of the feed screw 56, the left and right reticle holders 57 are separated from each other in a direction orthogonal to the optical axis or The distance can be adjusted within a certain range in a direction approaching and moving outward from a position where the center of the focusing screen 58 coincides with the optical axis.

Further, two cam plates 65 and 66 for separately moving the stereo slide holder 53 and the lens holder 55 back and forth are mounted at an intermediate portion of the feed screw 56. Stereo slide holder 53 and lens holder 5
Driven tappet rods 67 and 68 projecting in the directions of the cam plates 65 and 66 are fixedly attached to the extension springs 5, respectively.
The driven tappet rods 67, 68 are pressed against the cam plates 65, 66 by being urged by 9, 70. Therefore, the feed screw 5
6 by rotating the adjustment knob 64 of FIG.
The stereo slide holder 53 and the lens holder 55 are linked with the rotation of 66, and move back and forth within the range between the foremost position at an image magnification of 1: 1 and the rear enlarged projection position. Two cam plates 6
5 and 66 are formed in such a shape that the projected image of the focusing screen 58 is always kept in focus within the movement range of the stereo slide holder 53 and the lens holder 55, and the projection screen can be enlarged to an arbitrary magnification. it can.

When the stereo slide holder 53 and the lens holder 55 are moved in the direction in which the projection screen is enlarged,
The interval between the focusing screen holders 57 is increased in conjunction with the focusing screen holder 57, and the inside of the projection screen is masked by the screen frame of the focusing screen 58.
Since the inverted image on the focusing screen 58 is turned upside down and left and right by the erecting prism 60, the screen viewed through the eyepiece 61 of the erecting prism 60 is masked on the left and right sides.

If the actual screen width of the stereo slide and the screen width of the focusing screen 58 are 30 mm, for example, when the slide screen is enlarged and projected to 30/29, the projected screen width is 30 × 30/30. 29 = 31,034 (m
m), and the difference from the screen width of the reticle 58 of 30 mm is 3
1,034-30 = 1,034 (mm). Therefore, if the reticle 58 is at the initial position shown in FIG.
/ 2 = 0,517 (mm).

In the present mask amount guide device 51, the pitch of the feed screw 56 is set so that the left and right reticle holders 57 are shifted outward by 0.517 mm when the projection magnification is 30/29. As a result, in the inverted image viewed through the erecting prism 60, the left and right inner sides of the screen area of the reticle 58 coincide with the inner vertical sides of the slide projection screen, respectively. Then, the projection screen exceeding the outside of the screen of the focusing screen 58 is masked, and a mask width guide device 31 having a window width of 29 mm among the mask amount guide devices 31 shown in FIG. The masking rate is the same as that of a stereo slide viewer with a 1 mm mask on the outside of the camera.

As described above, regardless of the projection magnification, the inner edge of the focusing screen 58 and the inner edge of the slide projection screen appear to match, and the shielding area outside the screen can be continuously changed. . Then, as the projection magnification increases, the collimation pattern moves relatively inward with respect to the left and right projection screens, respectively, as in the case where the mask amount guide device 31 shown in FIG. , The perspective of the collimation pattern and the stereoscopic image fluctuates.

As shown in FIG. 8, the dial 71 of the adjustment knob 64 of the feed screw 56 has a screen shielding ratio corresponding to the number (# 0, # 1, # 2, # 3,...) Of the cover frame 22. The same numeral is written at the rotation position of. Therefore, the user adjusts the adjustment knob 64 while stereoscopically viewing the image while looking through the eyepiece 61 of the erecting prism 60 so that the foreground subject is located at the front / rear position substantially equal to the collimation pattern 59 of the reticle 58 or the depth of the collimation pattern 59. When the dial 71 is seen, the appropriate number of the cover frame 22 or the framing mask 41 can be recognized by looking at the number on the dial 71.

The interlocking mechanism of the stereo slide holder 53, the lens holder 55 and the reticle holder 57 is as follows.
Instead of the manual type shown in the drawing, each movable part is driven by a servomotor, and each movable part is electrically or magnetically or optically interposed with a position sensor to perform feedback control by a position control unit. You may comprise. Various modifications can be made to the configuration of each part within the technical scope of the present invention, and it goes without saying that the present invention extends to those modifications.

[0039]

As described above, in the stereo slide mount of the present invention, when the stereo slide is set at a predetermined position of the base frame and the cover frame is fitted, the mounting operation is completed, and the positioning and bonding of the stereo slide are performed. Work is unnecessary and mounting work is extremely easy.

Further, since the left and right sides of the cover frame are formed to be freely bent at the center, workability when mounting a stereo slide is extremely good. And, by using the mask amount guide device of the present invention, it is possible to objectively recognize the screen mask amount for exhibiting the best stereo effect even if the stereo slide is taken by any form of stereo camera, and If a cover frame or a framing mask having a mask amount is mounted, accurate parallax correction of a subject can be performed, and loss of a screen can be suppressed to a minimum.

Further, since the collimation pattern of the mask amount guide device is constituted by vertical lines, the difference in the sense of distance between the left and right images and the collimation pattern can be clearly recognized, and the number of the cover frame can be selected very easily. .

As described above, the stereo slide mount and the mask amount guide device of the present invention can eliminate the complexity and inaccuracy of the conventional stereo slide mounting operation and sufficiently exhibit the visual effect of stereo photography. This is an invention that contributes to the promotion of stereo photography.

[Brief description of the drawings]

FIG. 1 shows a stereo slide mount according to claim 1, wherein (a) is a front view of a base frame, and (b) and (c).
(D) is a rear view of the cover frame.

FIG. 2 is an assembly explanatory view of the stereo slide mount according to claim 1;

FIGS. 3 (a), (b), (c) and (d) are front views of a mask amount guide device according to claims 4 and 5, respectively.

4 (a) and 4 (b) are explanatory diagrams of binocular images of the mask amount guide device of FIG. 3 , respectively.

FIGS. 5 (a), (b), (c) and (d) are front views of the framing mask of the stereo slide mount according to claim 2;

FIG. 6 is an assembly explanatory view of the stereo slide mount according to claim 2;

FIG. 7 is a front view showing another embodiment of the framing mask shown in FIG. 5;

FIG. 8 is a front view of the mask amount guide device according to claim 6;

FIG. 9 is an explanatory diagram of a configuration of a mask amount guide device according to claim 6;

FIG. 10 is an explanatory diagram showing left and right screens of a stereo slide.

FIG. 11 is an explanatory diagram of a stereoscopic view screen of a stereo slide.

FIG. 12 is a developed front view of a conventional stereo slide mount.

13A and 13B show a conventional fixed-pitch stereo slide mount, wherein FIG. 13A is a front view of a cover frame, FIG. 13B is a cross-sectional view of FIG. 13A, and FIG. 13C is a front view of a base frame;
(D) is a sectional view of (c).

[Explanation of symbols]

 Reference Signs List 21 cover frame 21a hinge portion 22 base frame 23, 24 window 25 positioning pin 26 hole 31 mask amount guide device 32 frame 33 window 34 transparent film 35 collimation pattern 41 framing mask 41a cutout portion 42 window 51 mask amount guide device 52 slide guide Table 53 Stereo slide holder 54 Projection lens 55 Lens holder 56 Feed screw 57 Focusing plate holder 58 Focusing plate 59 Collimation pattern 60 Erect prism 61 Eyepiece F Slide film

Claims (7)

(57) [Claims] 1. A stereo slide mount for mounting a stereo slide photographed by a stereo camera in which the perforations of a perforated film and a pair of left and right photographing screens have the same relative position, each having two rectangles. The frame is composed of a base frame and a cover frame in which windows are juxtaposed, and engages with the perforation of a slide film to be fixed on the film mounting surface of the base frame so that the screens of the two slide films respectively match the windows. In a stereo slide mount, a positioning pin to be provided is provided, a hole corresponding to the positioning pin is provided on a film holding surface of the cover frame, and the positioning pin and the hole are fitted to join the base frame and the cover frame. The width between the left and right windows of the frame is A plurality of types of cover frames having the same width as the width between the windows of the base frame, and the window widths are sequentially reduced with respect to the screen width of the film, and the cover frame is selected and joined to the base frame to form a stereo slide. A stereo slide mount characterized in that the left and right outer shielding areas of the film can be adjusted. 2. A stereo slide mount for mounting a stereo slide photographed by a stereo camera in which the perforations of a perforated film and a pair of left and right photographing screens have the same relative position, each having two rectangles. The frame is composed of a base frame and a cover frame in which windows are juxtaposed, and engages with the perforation of a slide film to be fixed on the film mounting surface of the base frame so that the screens of the two slide films respectively match the windows. In a stereo slide mount, a positioning pin to be provided is provided, a hole corresponding to the positioning pin is provided in a film holding surface of the cover frame, and the positioning pin and the hole are fitted to join the base frame and the cover frame. With a shape equivalent to the slide film of A framing mask having a rectangular window at the center and having a locking hole for engaging with a positioning pin of the base frame, wherein a positional relationship between the locking hole and one vertical side of the window is a stereo slide. Creating a plurality of types of framing masks having the same positional relationship between the inner vertical side of the film screen and the perforation, and the window width being sequentially reduced from the screen width of the slide film, selecting the framing mask and selecting the base frame A stereo slide mount characterized in that the left and right outer shielding areas of the stereo slide film can be adjusted by overlaying the cover film on the upper slide film and fitting the cover frame to the base frame. 3. The stereo slide mount according to claim 1, wherein a hinge portion is provided at a central portion on the left and right sides of the cover frame to be bent. 4. A transparent film or a transparent glass is attached to each of the windows of the plurality of types of frames having the same shape as the cover frames having the plurality of types of window widths, and the same collimation pattern is provided at the same position on the left and right windows. 4. A mask width guide device used for a stereo slide mount according to claim 1, 2 or 3. 5. The mask width guide device for a stereo slide mount according to claim 4, wherein the collimation pattern is a pattern including a plurality of vertical lines or a plurality of vertical lines. 6. A stereo slide viewer having two left and right optical systems including a projection lens, a focusing screen, an erecting prism for inverting an inverted image on the focusing screen, and an eyepiece, wherein: Marking the same collimation pattern at the same position, a projection magnification adjustment mechanism for the image on the reticle,
A focusing mechanism for adjusting the distance between the reticle and the outer edges of the left and right focusing screens and an outer edge of the projection screen regardless of the projection magnification ratio; A mask width guide device for a stereo slide mount, wherein the relative positions of the collimation pattern and the projection screen are changed in accordance with a projection magnification rate. 7. The mask width guide device for a stereo slide mount according to claim 6, wherein the collimation pattern of the focusing screen is a pattern including several vertical lines or a pattern including several vertical lines.