JP3009301B2 - Flat-bed micro camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat-bed type micro camera for projecting a reduced image of a subject on a film sandwiched between an aperture mask and a flat plate.

[0002]

2. Description of the Related Art A film is sandwiched between an aperture mask (hereinafter simply referred to as a mask) perpendicular to the optical axis of a photographing lens and a pressure plate, and a reduced image of a subject by the photographing lens is projected on the film from a window of a frame formed on the mask. 2. Description of the Related Art Flat-bed type micro-cameras are known.

Here, the pressure plate can be pressed and separated from the mask, the film is fed with the pressure plate separated from the mask, and the film is fixed by pressing the pressure plate against the mask. The photographing is performed with the film fixed.

FIG. 10 is a perspective view showing a mask 1 conventionally used. A frame window 2 is formed in the mask 1 and a film 3 for guiding the film 3 moving on the frame window 2 is shown. Guide pins 4 and 5 are protruded. Then, the film 3 is pressed against the mask 1 by the pressure plate 6 from above the mask 1 to perform photographing.

FIG. 11 is a perspective view showing the lower surface of the pressure plate 6 used here, that is, the film pressing surface 7. The film pressing surface 7 has a flat central portion 7A, and both end portions 7B, 7B along the film running direction are flat surfaces one step lower than the flat surface of the central portion 7A.

In FIG. 11, a virtual line indicates a shape in which the entire film pressing surface is one plane. Also, an appropriate number of small holes 8 are opened in the central portion 7A, and a negative pressure is introduced into the small holes 8 to suck the film 3 into the central portion 7A during photographing.

[0007]

As described above, since the film pressing surface 7 of the conventional pressure plate 6 has a step between the plane of the central portion 7A and both ends 7B, a straight line in the film width direction is formed at the step. Are formed.

For this reason, when the film 3 is pressed by the pressure plate 6, the film 3 is pressed more strongly at the portions where the edges 9 and 9 hit than at the portions where the other flat portions 7A hit. Traces, i.e., indentations. For this reason, there was a problem that the image quality of the microfilm deteriorated.

The pressure plate 6 is pressed against the film 3 via a coil spring 6A as shown in FIG. 10, but since the coil spring 6A is helical, there is a slight gap between its two ends during compression and extension. Rotational force is generated. Therefore, when the pressure plate 6 is pressed against the film 3 or separates, the pressure plate 6 slightly rotates. There is also a problem that the rotation of the pressure plate 6 increases the impression due to the edge 9.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and a flat-bed type capable of improving the image quality of a microfilm without generating an impression on the film even when the film is pressed by a pressure plate during photographing. It is intended to provide a micro camera.

[0011]

According to the present invention, there is provided a frame formed by sandwiching a film between an aperture mask and a pressure plate perpendicular to the optical axis of a photographic lens, and forming a reduced image of the object by the photographic lens on the aperture mask. A flat-bed micro camera for projecting the film through a window, a coil spring for pressing the pressure plate against the aperture mask, and a small hole opening on a film pressing surface of the pressure plate;
Through which the film is sucked into the pressure plate during shooting
A pneumatic pump and a guide member provided on the frame side on which the aperture mask is mounted, abutting against a side surface of the pressure plate parallel to the film running direction to regulate rotation of the pressure plate accompanying compression and extension of the coil spring. Along with the film pressing surface of the pressure plate, a central portion along the film running direction is formed as a plane, and both end portions have a slope smoothly continuous with the plane of the central portion, and are formed from a plane including the central portion. This is achieved by a flat-bed micro camera, wherein the retreat amount is formed by a curved surface that continuously increases toward both ends.

It is to be noted that the film pressing surface may be not only gently retracted toward both ends but also gently retracted toward four corners .

[0013]

FIG. 1 is an external perspective view of a flat-bed type micro camera,
2 is a front view showing the internal structure of the camera, FIG. 3 is an enlarged perspective view near the mask, and FIG. 4 is an exploded perspective view near the pressure plate.

In FIG. 1, reference numeral 10 denotes a stand, and 12 denotes a horizontal photographing plate. A subject such as an original is placed in accordance with a corner mark of the photographing plate 12. On the stand 10, a column 14 stands vertically from the back side of the photographing plate 12, and a camera platform 16 is mounted on the column 14 so as to be able to move up and down. The camera mounting table 16 is fixed at a predetermined height in accordance with the image reduction ratio.

A photographing lens 18 (see FIG. 1) is fixed to the camera mount 16 vertically toward the photographing plate 12. A camera head 20 is mounted on the upper surface. The camera head 20 is rotatable around the optical axis of the lens 18, that is, the vertical axis, and can be fixed by tightening the lock lever 22.

Reference numeral 24 denotes an automatic exposure apparatus, 26 denotes a lamp cover having a built-in illumination lamp, 28 denotes a display panel, and 30 denotes a control panel. On the display panel 28, an operation status such as a frame size and a photographing operation is displayed. In the control panel 30, various settings such as setting of film sensitivity, number and mode for printing on the film, and the like are performed.

Next, the configuration inside the camera head 20 will be described with reference to FIGS. FIG. 2 shows a state where the cover plate 32 of the camera head 20 is opened upward. In FIGS.
Reference numeral denotes a supply box housed on the left side of the camera head 20, in which an unphotographed film 36 is housed. FIG. 2 shows the inside of the supply box 34 with the cover plate 38 also opened upward. In the supply box 34, a film 36 wound on a supply reel (not shown)
Is monitored by the swing lever 40.

An aperture mask 44 is detachably mounted on the lower frame 42 of the camera head 20 from the front. A frame window 46 is formed in the mask 44 as shown in FIG.
The mask 44 is fixed at a position on the optical axis. The mask 44 is provided with a light shielding plate 48 for judging the type of the mask. When the mask 44 is set on the frame 42, the camera head 20 automatically determines the type of the mask 44 from the position of the light shielding plate 48.

Reference numeral 50 denotes a guide roller, and reference numeral 52 denotes a drive roller, which are disposed on the left and right sides of the mask 44. The film 36 supplied from the supply box 34 reaches the upper surface of the mask 44 by being guided by the light shielding roller 54 provided in the supply box 34 and the guide roller 50. Then, it is sandwiched between the drive roller 52 and the contact roller 56, and is wound on a winding-side reel (not shown) while being given a predetermined tension by a tension roller 58. The take-up reel is loaded while being accommodated in a magazine (not shown), and engages with the take-up shaft 60 to rotate.

Here, the guide roller 50 and the drive roller 52 have an annular groove having a width substantially corresponding to the width of the film 36, and the width of the film 36 is restricted by the annular groove. The contact roller 56 has a width that engages with the annular groove of the drive roller 52, and engages in the annular groove to clamp the film 36 between the drive roller 52 and the drive roller 52. Therefore, the film 36 can be guided to a correct position on the mask 44 without providing the film guide pins (see pins 4 and 5 in FIG. 10) on the mask 44.

Reference numeral 62 denotes a pressure plate. FIG.
The upper plate 64 is overlapped as shown in FIG. A concave portion 68 is formed on the upper surface of the pressure plate 62 for forming an air chamber between the pressure plate 62 and the upper plate 64.
8 has a plurality of small holes 70 opened on the lower surface of the pressure plate 62.

At the center of the upper plate 64, a pipe 72 stands upright.
A coil spring 76 is compressed between a flange 74 fixed to the pipe 72 and the upper plate 64. A rubber tube 78 is connected to the pipe 72 (see FIGS. 2 and 3), and the other end of the tube 78 is connected to a diaphragm type air pump (not shown). The pipe 72 communicates with the recess 68 of the pressure plate 62.

The pressure plate 62 is driven up and down by an electromagnetic actuator 82 via an L-shaped bracket 80. That is, as shown in FIG. 4, a lower horizontal portion 80a of the bracket 80 is sandwiched between a washer 74 fixed to the pipe 72 and a coil spring 76, while a vertical portion 80b of the bracket 80 is provided with two screws on the frame 42. It is held movably up and down by 84 and 86.

The electromagnetic actuator 82 includes the plunger 8
2a and an electromagnetic coil 82b (FIG. 3), and the lower end of the plunger 82a is attached to the upper end of the vertical portion 80b by a pressure release lever 88. Both ends of a tension coil spring 90 are locked to the lever 88 and the lower screw 86.

For this reason, the plunger 82a and the bracket 80 are given a downward return behavior by the coil spring 90, and the pressure plate 62 is pulled by the tensile force of the spring 90.
Is pressed by the mask 44 via the coil spring 76. Accordingly, at the time of photographing, the film 36 placed on the mask 44 is positioned between the mask 44 and the pressure plate 62 and positioned.

At this time, the inside of the concave portion 68 is sucked to a negative pressure through the tube 78 and the pipe 72 by the plunger pump, and the film 36 is sucked from the small hole 70 to the lower surface of the pressure plate 62. For this reason, the film 36 adheres to the lower surface of the pressure plate 62 without loosening in the frame window 46 of the mask 44, and the planar accuracy of the film 36 at the time of photographing is improved.

When the film 36 is moved, the electromagnetic solenoid 82b of the electromagnetic actuator 82 is excited, and the pressure plate 62 is sucked upward together with the plunger 82a. As a result, the pressure plate 62 separates from the film 36, and the film 36 becomes movable. In this state, the drive roller 52 rotates by a predetermined angle, feeds the film 36 by one frame, and puts an unphotographed area of the film 36 into the frame window 46. The pressure plate 62 can be separated from the film 36 even when the pressure release lever 88 is pushed up with a finger.

Next, the film pressing surface 100 of the pressure plate 62 will be described with reference to FIGS. 5 is a front sectional view of the pressure plate assembly 102 including the pressure plate 62, FIG. 6 is a side sectional view of the same, FIG. 7 is a perspective view showing the film pressing surface 100 of the pressure plate 62, and FIG. Figure 7 for
9 is a sectional view taken along the line VIII-VIII in FIG.

As shown in FIG. 8, the pressing surface 100 has a flat surface at a central portion 100A, and curved surfaces at both ends 100B and 100B following the film running direction. The inclination of the curved surface changes continuously with the inclination of the central portion 100A, and the receding amount α from the plane A (FIG. 8) including the central portion 100A continuously increases from the central portion 100A toward the four corners. It is made like.

For example, in the front sectional view of FIG. 8, the center C is on a perpendicular line B to a plane A passing through the end of the central portion 100A.
An arc D of radius R ₁ with both end portions 100B shown in FIG. 9
In aspects diagram cross section, it is possible to a curved surface obtained by combining the arc G of radius R ₂ centered F on the vertical line E passing through the ends of the flat portion 100A.

The curved surfaces of both ends 100B may be formed by using other curves such as an elliptic curve and a quadratic curve instead of those formed by arcs D and E having radii R ₁ and R ₂ . FIG.
9 with the same radius R ₁ and R ₂ , R ₁ = R ₂ = R
In this case, the curved surface toward the four corners is formed by a spherical surface, and the present invention naturally includes such a surface.

In this embodiment, both ends 100B, 100B are curved not only along the film running direction but also along the film width direction (see FIG. 9).
For this reason, the effect of the present invention becomes more remarkable. However, the present invention may use a curved surface which does not have a curved surface shape in the film width direction but is curved only in the film traveling direction.

Further, since the pressure plate assembly 102 is pressed against the film 36 via the coil spring 76, the pressure plate 62 is
A slight rotational force acts around the center 2. Therefore, at the moment when the pressing plate 62 presses or releases the film 62,
Will rub the back of the film 62,
This is one of the causes of indentation.

Therefore, in the present invention, as shown in FIGS. 5 and 6, the guide member 104 abutting on the side surface of the pressure plate 62 parallel to the film running direction is fixed to the frame 42 by screws 106, 106. As a result, when the pressure plate 62 moves up and down, the pressure plate 62 slides on the guide member 104 to restrict its rotation, and the pressure plate 62 moves up and down without rotation.

[0035]

According to the first aspect of the present invention, as described above, the center portion (100) of the film pressing surface (100) of the pressure plate (62).
A) is a plane, and both ends (100B) have an inclination smoothly continuing to the center plane, and the retreat amount (α) from the plane (A) including the center plane is continuous toward both ends. Since the curved surface is increased, the film pressing surface (100)
No edge is formed on the film, and there is no danger of indenting the film. Also when pressure plate (62) contacts and away from the film (36), while the pressure plate (62) is to slightly rotate by the compression and decompression of the coil spring, the film
(36) opens on the film pressing surface (surface) of the pressure plate (62).
The pressure plate (6
Since the film is sucked by the film pressing surface of 2), the pressure plate (6
2) rubs the back of the film (36) to produce indentations
May be affected. However, according to the present invention, since the rotation of the pressure plate (62) is regulated by the guide member (104), the pressure plate (62) can also be prevented from rubbing against the back surface of the film (36), and the indentation can be reliably reduced. . Therefore, the image quality of the microfilm is improved.

Here, both ends (100B) are not only curved in the film running direction but also curved in the film width direction so that the receding amount (α) is continuous toward the four corners. It is also possible to use a curved surface that increases in number .

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a flat-bed micro camera.

FIG. 2 is a front view showing the internal structure of the camera head.

FIG. 3 is an enlarged perspective view near a mask.

FIG. 4 is an exploded perspective view showing the vicinity of a pressure plate.

FIG. 5 is a front sectional view of the pressure plate assembly.

FIG. 6 is a side sectional view of the same.

FIG. 7 is a perspective view showing a film pressing surface of a pressure plate.

8 is a sectional view taken along line VII-VII in FIG. 7;

9 is a sectional view taken along line IX-IX in FIG. 7;

FIG. 10 is a perspective view showing the vicinity of a mask of a conventional apparatus.

FIG. 11 is a perspective view showing a film pressing surface of a conventional pressure plate.

[Explanation of symbols]

Reference Signs List 18 shooting lens 36 film 44 aperture mask 46 frame window 62 pressure plate 76 coil spring 100 film pressing surface 100A central portion 100B both end portions 104 guide member A plane including central portion α Retreat amount

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03B 27/32

Claims (2)

(57) [Claims] 1. A flat-bed type in which a film is sandwiched between an aperture mask and a pressure plate perpendicular to an optical axis of a photographing lens, and a reduced image of a subject by the photographing lens is projected onto the film through a frame window formed in the aperture mask. in the micro camera, a coil spring that presses the pressure plate in the aperture mask, the pressure plate Fi
When shooting through the small hole opening on the
An air pump that sucks the pressure plate into the pressure plate, and a rotation of the pressure plate caused by the compression and extension of the coil spring by contacting a side surface of the pressure plate, which is provided on the frame side on which the aperture mask is mounted, parallel to the film running direction. And a guide member for regulating the pressure, the film pressing surface of the pressure plate, a central portion along the film running direction is formed in a plane, both ends have a slope smoothly continuous with the plane of the center and A flat-bed type micro camera characterized in that it is formed as a curved surface in which the retreat amount from a plane including a central portion continuously increases toward both ends. 2. The film pressing surface of the pressure plate, wherein corners from the central portion toward four corners are formed as curved surfaces in which the amount of retreat from a plane including the central portion continuously increases. Flat floor type micro camera.