JPS6345085B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a projection lens holding device used in a microfilm reader, microfilm reader printer, etc., and particularly to a projection lens holding device whose focus can be adjusted by rotational operation.

A conventional projection lens holding device of this type, such as a microfilm reader, generally has a configuration as shown in FIG. This is pressure plate glass 1a
and the lower glass plate 1b.
Then, by irradiating illumination light from below, a projected image of the film F is formed on a transmission screen 6 via a projection lens 3, a first mirror 4, and a second mirror 5. The illumination light is produced by condensing the light emitted by the illumination lamp 7 with a reflecting mirror 8 and condensing lenses 9, 10, 11 and a cold mirror 1.
2 by effectively guiding the film F. Pressure plate glass 1a, lower plate glass 1b
and the handle 1c are integrated into the film carrier 1.
By moving the handle 1c back and forth, left and right, the film F held between the pressure plate glass 1 and the lower glass plate 1b is properly aligned.

The projection lens 3 includes a lens portion 3a and a lens holder 3.
b and a holder support member 3c. A plurality of optical lenses are fixedly arranged inside the lens section 3a according to the projection magnification. The lens portion 3a is removably fitted into the lens holder 3b from above. The lens holder 3b is screwed into a holder support member 3c, and its rotation causes the lens holder 3b to move in the vertical direction.
In FIG. 1, bosses 3d are formed on the front side and the back side of the holder support member 3c. The plate spring 13 extending from the main body presses the boss 3d downward, so that the holder support member 3c is attached to the pressure plate glass 1.
It is crimped on top a, and its position in the front, rear, left and right directions is also restricted. Also, a ring 3e is attached to the lens holder 3b.
is provided around the ring 3e, and a longitudinal knob 3f is fitted into a screw hole formed in the ring 3e so as to be movable in the longitudinal direction.

Therefore, in the conventional example described above, the transparent screen 6
Focus adjustment of the above projected image is performed by pinching the knob 3f and slightly rotating it left and right around the optical path l. That is, this is done by rotating the lens holder 3b with respect to the holder support member 3c and changing the relative distance between the lens portion 3a and the film F. Further, when converting the projection magnification, the lens portion 3a is extracted upward from the lens holder 3b and replaced with another lens portion having the desired magnification.

However, since only one focus adjustment knob 3f is provided on the outer periphery of the projection lens 3,
To adjust the focus, use one of the knobs, 3.
The only option was to pinch f and rotate the lens holder 3b. Therefore, in a device with limited space, the operating range of the knob 3f is limited.
The maximum rotation angle range of lens holder 3b is 90
Therefore, a sufficient adjustment range could not be obtained. In addition, in order to obtain a sufficient focus adjustment range, that is, a vertical movement range with such a rotation angle, the lens holder 3b and the holder support member 3
It becomes necessary to widen the pitch of the thread formed at the threaded part with c. However, doing so would make it impossible to make fine adjustments.

Furthermore, the knob 3f may be forced to be operated in a narrow space at the back of the device, and in this case there is a problem that the operation is inflexible and the range of movement is considerably limited.

Therefore, in Japanese Patent Application Laid-Open No. 47-22124, a drive transmission mechanism such as a gear is provided to connect the projection lens and an operating wheel provided on the operating section on the front of the device, and the focus is adjusted by rotating the operating wheel. is known, but there is a problem that the structure of the device becomes complicated.

In addition, when the projection lens is attached to a reader or the like, a leaf spring 13 is attached to the reader body so that the lower end surface of the holder support member 3c is always in contact with the pressure plate glass 1a in order to maintain a constant distance between the projection lens and the film. However, in order to equip a reader etc. with a focus adjustment mechanism and a constant distance maintenance mechanism, a complex mechanism must be integrated into one piece, which is difficult to manufacture. There was a problem in that the lens unit was extremely complicated and the work of replacing and repairing the lens unit was also complicated.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and provide a projection lens holding device with good operability and high operating precision.

In order to achieve the above object, the present invention provides a plurality of rotating operation handles (knobs) on the outer periphery of a projection lens, and the projection lens is rotated by holding any of the handles. This makes it possible to adjust the focus.

Embodiments of the present invention will be described below with reference to the drawings.

First, based on FIG. 2, a microfilm reader to which an embodiment of the projection lens holding device of the present invention is applied will be schematically described. Here, the first
As shown in the figure, the film carrier 1 is the pressure plate glass 1.
a, a lower glass plate 1b, and a handle 1c.

In order to illuminate the film F held between the pressure plate glass 1a and the lower plate glass 1b, the light from the illumination lamp 7 is focused by a concave reflecting mirror 8, passed through condenser lenses 9 and 10, and then reflected by a cold mirror 12. Only the cold water is directed upward by 90 degrees and further effectively guided to the film F via the condenser lens 11. The light transmitted through the film F passes through the lens fixing member 30, which is a feature of the present invention.
The light is reflected by the first and second mirrors 4 and 5 through the projection lens holding device 20 fixed by the projection lens holder 20, and forms a projected image on the transmission screen 6.

An embodiment of the projection lens holding device 20, which is a feature of the present invention, will be described based on FIGS. 3 to 8. As shown in the plan view of FIG. 3, the projection lens holding device 20 schematically includes a lens portion 20a.
, lens holder 20b, and holder support member 20
c and are integrally constructed so that they can be attached to and detached from each other.

As shown in FIG. 4, the lens portion 20a has a plurality of optical lenses L therein, and the optical lenses L have their optical axes aligned with each other and are arranged at predetermined intervals according to the projection magnification. has been done.

As shown in FIGS. 5 and 6, the lens holder 20b has a plurality of handles (knobs) 20d arranged radially along the outer periphery of a cylindrical portion 20e.
The handle portions 20d have an appropriate length in the radial direction of the lens holder 20b so that they can be easily grasped, and are arranged at approximately constant intervals so that a normal person's fingers can fit comfortably. desirable. The handle portion 20d shown in the figure is a substantially rectangular flat plate, but if it is shaped like this, it is possible to provide ample space for inserting fingers, and the plurality of handle portions 20d can be attached to the outside. You can also hold it by wrapping it up. Of course, other shapes such as elongated rods may be arranged radially around the outer periphery to achieve the desired purpose. The cylindrical portion 20e is further formed with a plurality of claw portions 20f having appropriate elasticity at rotationally symmetrical positions. As shown in Fig. 4, the cylindrical part 2
The lens portion 20a is tightly fitted into the lens portion 0e and dropped into the lens portion 0e, and the claw portion 20f is normally engaged with the stepped portion 20g of the lens portion 20a, so that the lens portion 20a and the lens holder 20b are integrated. becomes fixed.

As shown in FIGS. 7 and 8, the holder support member 20c has a ring-shaped hook portion 20i on the outer periphery of the cylindrical portion 20h, with its central axis aligned, and is further attached via an elastic member (connection member) 20j. It is provided.
The hook portion 20i acts as an engaging portion with the main body of the device, as will be described in detail later. Elastic member 20j
As is clear from FIG. 7, it has a rotationally symmetrical shape with respect to the central axis k of the cylindrical portion 20h. This prevents the cylindrical portion 20h from moving in a direction perpendicular to the central axis k when the hook portion 20i is fixed to the main body of the device, and allows for moderate movement in the direction of the axis k. This enables so-called gyro movement in which the central axis k can be tilted as k' or k''.Furthermore, a threaded portion 20k is provided inside the cylindrical portion 20h.
As shown in FIG. 4, it can be screwed into a threaded portion 20l formed on the outer lower side of the lens holder 20b. This is because rotating the lens holder 20b with respect to the holder support member 20c changes the relative position thereof. That is, the lens part 20a fitted in the lens holder 20b and the film F shown in FIG.
The projection image of the film F formed on the transmission screen 6 is focused by changing the distance from the transmission screen 6.

Next, the means for engaging the projection lens holding device 20 and the main body of the device will be explained. The main body of the apparatus is provided with a lens fixing member 30 as shown in FIGS. 2, 9, and 10. The lens fixing member 30 is integrally constituted by an upper guide 30a, a lower guide 30b, and a central hook portion 30c.

The upper guide 30a and the lower guide 30b have a substantially U-shaped shape corresponding to the outer shape of the hook portion 20i so as to wrap around approximately half of the hook portion 20i shown in FIG. The hook portion 20i can be slid and held between the two. The two distal ends 30d of the lens fixing member 30 have relatively wide openings to facilitate insertion of the hook portion 20i from the direction of arrow X.

The hook portion 30c is formed with appropriate elasticity, and is similar to the hook portion 20 of the holder support portion 20c.
When i is completely housed in the guides 30a, 30b, it is fixed in a predetermined position as shown in FIG. 11 by engaging with the hook portion 20i. As such an engaging means, a hook portion 20 is used.
The present invention is not limited to 1, 30c, and the desired purpose can also be achieved by using, for example, a so-called roller catch, ball catch, or magnet. Also, hook 30c
It may be configured such that the hooks 20i engage from below and the hooks 20i engage from above.

Note that the upper guide 30a and the lower guide 30b
It is desirable that the projection lens holding device 20 be disposed horizontally and at a constant distance from the pressure plate glass 1a so as to bring the projection lens holding device 20 into close contact with the pressure plate glass 1a as shown in FIG. As shown in FIG. 11, the above-mentioned interval is determined by the elastic deformation of the elastic member 20j when the projection lens holding device 20 is attached.
The speed is set so that the plate is pressed onto the pressure plate glass 1a.

Since this embodiment has the above-mentioned configuration, replacement of the projection lens holding device 20 for projection magnification conversion and focusing can be performed as follows.
(i) When removing, (ii) when attaching, and (iii) when focusing the projection lens holding device 20 will be explained together with their respective functions and effects.

(i) At the time of removal: As shown in FIG. 11, the projection lens holding device 20 is elastically engaged from above and below by a hook portion 20i and a hook portion 30c. Therefore, in FIG. 11, their engagement can be released by simply pinching the left end of the hook portion 20i and pulling it on the pressure plate glass 1a in the direction of the arrow Y using the force of velocity. Therefore, even if the mirror 4 is disposed directly above and close to the projection lens holding device 20, it is possible to easily take out only the projection lens holding device 20 without having to move or remove it. . Furthermore, since the hook portion 20i is continuously provided on the outer periphery of the projection lens holding device 20, the portion to be pinched is not limited to one place, and can be pinched from any direction.
Also, by using both hands to pinch in two places, the force is shared and you can pull it out more easily.

It is also possible to hold the entire handle and pull it out.

(ii) At the time of installation: Select the desired one from the extra projection lens holding devices 20 of various magnifications prepared. Since a hook portion 20i is continuously formed on the outer periphery of the projection lens holding device 20, when attaching it to the main body, any part of the hook portion 20i can be pinched from any direction. Then, lightly pinch it and slide it on the pressure plate glass 1a.
It is inserted into the lens fixing member 30 from the direction of arrow X shown in the figure. The hook portion 20i is the hook portion 30c.
The installation is completed in the specified position by engaging the two. In this manner, even when the mirror 4 is attached, it is not necessary to move the mirror 4, etc., and the mirror 4 can be easily and reliably used. Furthermore, there is no need to attach the lens part 20a, lens holder 20b, and holder support member 20c separately, and they can be attached as a pair from the beginning, so that the relative positions of these individual members may be misaligned each time they are replaced. There is no problem at all, and the high accuracy can be maintained.

Further, the hook portion 20i is securely held in place by the upper and lower guides 30a and 30b, and furthermore, as shown in FIGS. 7 and 8, an elastic member 20 having a specific shape and movement direction
It is coupled to the holder support member 20c via Oj. Therefore, the projection lens holding device 20 itself is reliably positioned on the pressure plate glass 1a. Furthermore, even if the relative positional relationship between the lens fixing member 30 and the pressure plate glass 1a changes in the vertical direction, the holder support member 20c performs vertical movement and gyroscope movement as shown in FIG. Apparatus 20 and pressure plate glass 1
There is no deviation in the relative position with respect to a in the front, rear, left, and right directions, which prevents subtle deviations of the optical axis and improves accuracy.

(iii) Focusing: Focusing is performed by rotating the lens holder 20b with respect to the holder support member 20c and changing its vertical position. Furthermore, the fifth
As shown in the drawings, the lens holder 20b has a plurality of handles 20d arranged around its outer periphery at regular intervals. When rotating the lens holder 20b, either handle portion 20d may be pinched and operated. Therefore, the grip portion is not limited to one location, and the handle portion 20d, which is located at the most easily operated position, can be gripped from any direction. In addition, a plurality of handle portions 20
Since it is also possible to operate the device while holding it in a manner that wraps the entire device from the outside, a large degree of freedom is given to the operating means.

Further, since the rotation angle range of the lens holder 3b is not limited, a sufficient focus adjustment range, that is, a vertical movement range can be obtained.
Therefore, the lens holder 3b and the holder support member 3c
Threaded portions 20l, 2 formed at the threaded portion with
By narrowing the pitch of 0k, even finer adjustment is possible.

As explained above, the present invention provides a plurality of knobs extending in a direction substantially perpendicular to the optical axis of the lens, which facilitates the rotation operation in a narrow space at the back of the film projector, and furthermore allows the rotation operation to be carried out within the rotation range. This has the very excellent effect of eliminating restrictions and enabling highly accurate focus adjustment.

Further, since there is no need to provide a drive transmission mechanism between the focus adjustment operation section and the lens as in the conventional case, the structure of the apparatus is simplified, and the apparatus can be made smaller and less expensive.

Furthermore, although it has a focus adjustment function and a constant distance maintenance function, it has a simple structure, is easy to manufacture and assemble, and can easily perform operations such as replacing and repairing the lens unit. In addition, by adjusting each lens unit to the proper focus state, there is no need to perform focus adjustment again each time a lens unit is attached, detached, or replaced. Appropriate images can be viewed and printed.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a conventional microfilm reader, Fig. 2 is a schematic diagram showing an embodiment of a microfilm reader using a projection lens holding device according to the present invention, and Fig. 3 is a schematic diagram showing a projection lens holding device according to the present invention. FIG. 4 is a plan view showing one embodiment of the third embodiment.
5 is a plan view showing an embodiment of the lens holder according to the present invention, FIG. 6 is a sectional view taken along BB in FIG. 5, and FIG. 7 is a sectional view of the holder according to the present invention. FIG. 8 is a plan view showing an embodiment of the support member, FIG. 8 is a sectional view taken along the line CC in FIG. 7, FIG. FIG. 11 is a partial front sectional view showing a state in which the projection lens holding device is attached to the lens fixing member. 20... Projection lens holding device, 20a... Lens part, 20b... Lens holder, 20c... Holder support member, 20d... Handle part, 20e... Cylindrical part, 20f... Claw part, 20g... Step part , 20h
...Cylindrical part, 20i...Hook part, 20j...Elastic member, 20k, 20l...Screw part, 30...Lens fixing member, 30a...Upper guide, 30b...
...Lower guide, 30c...Hook part, 30d...
tip.

Claims (1)

[Claims] 1. A lens holder that supports a lens and is movable in the optical axis direction; a holder support member that rotatably supports the lens holder; and a holder support member that is provided on the lens holder and extends approximately perpendicularly from the outer circumference of the lens holder;
A lens unit is provided with a plurality of operation knobs for adjusting the focus of the lens by rotating the lens holder, a holder support member supports the lens holder, and a lower end surface is in contact with a film pressure plate of a film projection device. a cylindrical part arranged along the outer periphery of the cylindrical part and detachably supported by a fixed part of the film projection device; A projection lens holding device characterized by having a connecting member for connecting.