JP4733866B2 - Projection lens device and spotlight equipped with the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a projection lens device (commonly known as a front lens) used in an effect spotlight system that projects various effect images on a horizont or stage floor behind the stage, thereby providing stage effects.
[0002]
[Prior art]
An effect spotlight system that provides stage effects is a lamp body (light source) equipped with a light bulb and a reflector, an effect machine placed in front of the lamp body, and light transmitted through the effect machine. It is composed of a projection lens device (tip lens) that projects (effect image) onto a horizont or a stage floor surface.
Then, the projection lens device has two plano-convex lenses facing the convex surfaces inside a cylindrical holding metal fitting made of a metal plate (for example, an aluminum alloy plate) that is open on both axial sides. And the lid is screwed.
[0003]
The two lenses are configured to move along the axial direction while maintaining the distance therebetween, and the lens feeding mechanism is configured by a combination of only a rack and a pinion.
[0004]
[Problems to be solved by the invention]
By the way, the projection lens apparatus has the following drawbacks due to the above-described configuration.
(1) The image is not clear due to spherical aberration (in the narrow sense).
(2) The negative distortion of the image is large (the projected image becomes a pincushion).
(3) The chromatic aberration is large.
(4) There is a large deviation (curvature of field) between the center and peripheral focus positions.
(5) When the projection lens is determined, the only way to blur the projected image is to remove the focus and blur.
(6) Since the holding bracket for storing the lens is not completely sealed like a photographic lens, the lens becomes dirty during use, and it takes a lot of work to remove the lens to clean it.
(7) Even when an attempt is made to adjust the sharpness of a projected image by inserting a stop between two lenses, it is not easy to attach (remove) the stop.
(8) Since the lens moves when the hand is released after focus adjustment, a separate lock mechanism is required to prevent the adjustment state from changing.
Therefore, conventionally, a plurality of projection lens devices comprising a combination of lenses having different focal lengths are prepared, and the optimum projection lens device is selected and used according to the purpose of the projection effect.
[0005]
The present invention has been made in view of the above-described problems of the prior art. The object of the present invention is to provide a projection that eliminates the conventional drawbacks and can be used in accordance with the purpose of use by changing the combination of lenses. It is in providing a lens apparatus.
[0006]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the technical means taken by the present invention includes a cylindrical protective case in which openings for transmitting light are formed on both sides in the axial direction, and an axial direction in the protective case. The lens holding cylinder is housed and arranged so that it can be moved back and forth, and a plurality of lenses are supported in the lens holding cylinder at a substantially right angle with respect to the axis. The position of the lens holder can be adjusted, and the lens holding cylinder is configured to be openable and closable so that a part of its constituent members can be attached and detached in the direction intersecting the axis. The present invention is characterized in that an opening / closing lid is provided that enables the opening / closing member of the cylinder to be attached and detached.
The standard number of lenses to be accommodated in the lens holding cylinder is three, and it is divided into two and one, and a clear image projected by placing them at a distance, and one lens. Is changed to a two-image configuration, and the two images are adjusted to project a blurred image arranged at a distance. The long focal point can be constituted by two lenses.
[0007]
The protective case may have a cross-sectional shape that can accommodate the lens holding cylinder. For example, if the lens holding cylinder is a substantially regular octagon, it may be any of a substantially regular quadrangular cylinder or a circular cylinder that can enclose it.
As a structure for supporting the lens in the lens holding cylinder so that the position of the lens can be adjusted, an engagement hole is formed in the peripheral wall of the holding cylinder so that the periphery of the lens is fitted, and the lens periphery is fitted in the engagement hole. Examples include a structure or a structure in which a receiving frame having a U-shaped cross section is attached to the inner surface of the peripheral wall of the holding cylinder, and the lens periphery is inserted into the receiving frame.
The engagement hole for fitting the peripheral edge of the lens may be a simple rectangular hole, but it may be a stepped rectangular hole with a large number of locations that abut and engage with the lens so that it can be stably supported.
[0008]
In addition, as a structure in which a part of the peripheral wall that intersects the axis of the lens holding cylinder can be attached and detached, the lens holding cylinder is constituted by two halves, and the other half is the other part. Make the half part detachable. Alternatively, any structure may be used, such as a structure in which a hole is opened in the peripheral wall of the cylinder and a lid that closes the hole is attached in an openable / closable manner.
The movement adjustment mechanism for moving the lens holding cylinder in the front-rear direction along the axis of the protective case may be configured by a rack and a pinion as in the past, but by configuring it by a combination of a worm and a rack and pinion, The fluctuation after adjustment can be prevented.
Furthermore, an aperture plate is arranged between the lenses. However, it is also possible to provide latch holding means such as an aperture plate removed from the lens holding tube or a spare aperture plate with a different aperture diameter on the inner side of the opening / closing lid of the protective case. Good.
[0009]
According to the above means, the lens supported on the inner side of the lens holding cylinder can be attached and detached by opening the opening / closing lid of the protective case and removing the opening / closing member of the lens holding cylinder housed inside. For example, when projecting a clear image, three plano-convex lenses are divided into one and two, two plano-convex lenses are arranged on the rear side in the projection direction with the convex surface side facing each other, and 1 on the front side in the projection direction. A plano-convex lens is disposed with its convex surface facing forward, and a diaphragm plate is disposed between the two lenses and the one lens. When changing to the projection of a blurred image, the opening / closing lid of the protective case and the opening / closing member of the lens holding cylinder are removed, one lens is removed, and the two lenses are respectively directed with the convex side facing rearward, and both By disposing the lenses at an interval and moving the diaphragm plate to the front in the projection direction, a blurred image can be projected.
In addition, the lens can be easily attached to and detached from and changed in position by the structure in which the lens periphery is fitted into the engagement hole formed in the peripheral wall of the lens holding cylinder.
Furthermore, when the movement adjustment mechanism for the lens holding cylinder is configured by a combination of a worm and a rack and pinion, the lens holding cylinder does not move even after the hand is removed from the knob after adjustment, and the adjusted state is maintained.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a use state in which a spotlight having a light source and a reflecting mirror is combined with an effect machine equipped with an effect pattern (seed plate). In the figure, A is a projection lens device according to the present invention, and its projection The lens apparatus A is detachably attached to the front part of an effect machine C that is mounted with a replaceable effect pattern attached to the front part of the effect spotlight B including the light bulb (light source) b1 and the reflecting mirror b2.
[0011]
The projection lens apparatus A includes a protective case 1 formed in a cylindrical shape having a substantially square cross section using an aluminum alloy plate, and is housed inside the protective case 1 and can be moved and adjusted in the front-rear direction along the axial direction. A lens holding cylinder 2 to be supported, a plurality of plano-convex lenses 3a, 3b, 3c and a diaphragm plate 4 accommodated in the lens holding cylinder 2, and a movement adjusting mechanism for moving and adjusting the lens holding cylinder 2 in the front-rear direction. And 5.
[0012]
Protective case 1 is attached to the rear end of the cylinder 1a formed with an aluminum alloy plate, the filter holder frame 1b having an opening attached to the front end in the axial direction of the cylinder 1a, and the cylinder 1a. A side frame composed of a plate 1c, wherein the cylindrical body 1a is formed by folding a bottom plate, one side surface, and about half of the top surface in the width direction into a substantially U shape with a single plate. 6 and an opening / closing lid 7 formed by bending the other side surface and half of the upper surface into a substantially L-shape with a single plate. The opening / closing lid 7 has a hinge at the end of the side surface at the end of the bottom surface of the side frame 6. 9 is connected so that opening and closing is possible. Further, the upper surface side of the opening / closing lid 7 is configured to be brought into contact with the upper surface side of the side frame 6 and detachable by a lock 8. Accordingly, when the lock 8 is removed, the opening / closing lid 7 rotates outwardly about the hinge 9 and the half of the upper surface is opened from the side surface of the protective case 1.
[0013]
The lens holding cylinder 2 accommodated in the protective case 1 is a cylindrical body having a substantially regular octagonal cross section, and the cylindrical body, like the protective case 1, is a side on which an octagonal surface is formed using an aluminum alloy plate. It is composed of two members, a frame 2a and a side frame 2b formed for the remaining three surfaces, and one side frame 2a is installed on the bottom inner surface of the protective case 1 in parallel along the axis. It is placed and fixed on the base frames 11 and 11 ′ that are slidably mounted over the guide rods 10 and 10 ′.
The other side frame 2b is detachably attached to the side frame 2a, so that the side frame 2b functions as an opening / closing member.
[0014]
In the configuration in which the side frame 2b is detachably attached to the side frame 2a, the latch holes 12 are formed in the front and rear portions of the upper edge of the side frame 2a, and the side of the other side frame (opening / closing member) 2b. A leaf spring 13 that is bent in a deformed shape is fixed to the front and rear portions of the edge, and the leaf spring 13 is inserted into the latch hole 12 to form a hinge structure, and the side frame 2a and the side frame 2b are opened. The ends are detachably connected by a buckle-like latch 14.
[0015]
As described above, on the peripheral wall of the lens holding cylinder 2 configured in a substantially regular octagonal cylinder shape with the side frame 2a and the side frame 2b, an engagement hole 15 for fitting the periphery of the plano-convex lenses 3a to 3c, and a circular shape A plurality of sets of engagement grooves 16 for fitting the periphery of the diaphragm plate 4 that has been made transparent are opened at intervals in the axial direction, and the plano-convex lenses 3a to 3c and the diaphragm plate 4 are arranged according to the purpose of projection. The arrangement position can be changed. Although the drawing shows a form in which the engagement groove 16 is formed only at one place, a plurality of engagement grooves 16 are formed along the axial center, and the arrangement position of the diaphragm plate 4 is changed back and forth according to the production purpose. You may make it adjust.
Then, the engagement holes 15 into which the peripheral edges of the plano-convex lenses 3a to 3c are fitted are stepped rectangular holes as shown in the figure, so that the number of contact points with the lens is increased and the lens is stably supported. I can do it. Of course, the engagement hole 15 may be a simple rectangular shape without a stepped shape. Further, the stepped shape of the engagement hole 15 may be formed only on one side of the long side, but may be formed on both sides of the long side. In this case, even when the orientation of the plano-convex lens is changed at the same position, the operation of the stable support by the multipoint support described above is maintained.
[0016]
Further, in the space between the upper corner of the side frame 2a of the lens holding cylinder 2 and the protective case 1, there is a movement adjusting mechanism 5 for moving and adjusting the lens holding cylinder 2 in the front-rear direction along the axial direction. Contained.
The movement adjusting mechanism 5 includes a rack 5a that is vertically fixed on the outside of the vertical surface of the side frame 2a in the lens holding cylinder 2, a pinion gear 5b that meshes with the rack 5a, and a pinion gear 5b that rotates. The pinion gear 5b, the worm wheel 5c, and the worm gear 5d are fixedly held by the bracket 17 inside the side frame 6 constituting the protective case 1. The rotating shaft integral with the worm gear 5d is protruded through the outside of the protective case, and an adjustment knob 5e is fixed to the protruding end portion.
[0017]
Accordingly, when the adjustment knob 5e is rotated, the rotation is transmitted as worm gear 5d → worm wheel 5c → pinion gear 5b, and the rack 5a meshing with the pinion gear 5b is moved in the front-rear direction along the axial direction. Focusing is performed.
Then, between the pinion gear 5b and the worm wheel 5c coaxial with the worm gear 5d, the rotation direction is converted to a right angle direction, so that the lens holding cylinder 2 to which the rack 5a is attached does not naturally move. .
[0018]
The diaphragm plate 4 is an aluminum alloy plate formed in a shape that matches the cross-sectional shape of the lens holding cylinder 2, and an opening for narrowing the light to a predetermined diameter is opened at the center thereof. A protrusion 4 ′ that fits into the engagement groove 16 is formed. The diaphragm plate 4 is prepared in several types (two types in the drawing) with different aperture diameters, and the unused diaphragm plate 4 is provided inside the protective case 1 so that it can be carried with the projection lens device A. A stop holding means 18 for the diaphragm plate 4 is provided.
The latch holding means 18 engages the inner surface of the side frame (opening / closing lid) 7 constituting the protective case 1 with a hook-shaped receiving frame 18 a for receiving one side of the diaphragm plate 4 and the opposite side of the diaphragm plate 4. A rectangular hole is formed in the bottom of the receiving frame 18a so that the diaphragm plate 4 accommodated in the receiving frame 18a is not displaced from side to side.
In the figure, 19 is a carrying handle attached to the upper surface of the protective case 1.
[0019]
Next, the use of the projection lens device A will be described. When a clear image is projected, as shown in FIGS. 1 to 4, the lock 8 of the protective case 1 is removed and the side frame (open / close lid) 7 is attached. The lens holding cylinder 2 is opened, the lock 14 is removed, the opening / closing member 2b is removed, and a part of the side surface and the upper surface of the lens holding cylinder 2 is opened. Then, the three plano-convex lenses 3a, 3b, 3c are divided into one and two, and the one lens 3a is disposed in the front of the projection direction in the lens holding tube 2 with its convex surface side facing forward, The two lenses 3b and 3c are arranged on the rear side in the projection direction of the lens holding cylinder 2 so that the convex surfaces face each other, and the diaphragm plate 4 is arranged between the lens 3a and the lenses 3b and 3c. The plano-convex lens and the diaphragm plate 4 are vertically supported by inserting and fitting the peripheral edge of the lens and the projection 4 ′ of the diaphragm plate 4 into the engagement holes 15 and the engagement grooves 16 formed in the peripheral wall of the lens holding cylinder 2. By closing and attaching the opening / closing member 2b, the lenses 3a to 3c and the diaphragm plate 4 are fixed without rattling due to the spring action of the hinge of the opening / closing member 2b and the elasticity of the material constituting the lens holding cylinder 2. Therefore, the spring action of the hinge of the opening / closing member 2b and the elasticity of the material constituting the lens holding cylinder 2 can be fixed without rattling even if there is some manufacturing error in the thickness and diameter of the lens to be accommodated. Note that the sharpness and brightness of the image can be changed by replacing the diaphragm plate 4 disposed in the middle of the lens with one having a different aperture diameter. When the aperture diameter is reduced (smaller), the image becomes clearer and darker.
[0020]
When the projected image is blurred, the lock 8 that closes the side frame (opening / closing lid) 7 of the protective case 1 is removed, the side frame (opening / closing lid) 7 is opened, and the opening / closing member of the lens holding cylinder 2 is opened. The lock 14 engaging the 2b is removed, the opening / closing member 2b is removed from the side frame 2a, and an opening to substantially half of the peripheral surface of the lens holding cylinder 2 is opened. Then, an extra lens is removed through this opening, and the remaining two lenses are moved to the position indicated by the phantom line in FIGS. 1 and 2 with the convex surface side moved rearward, and the two lenses. A diaphragm plate is arranged in front of the projection direction. The fixing of the lens and the diaphragm plate can be easily changed by inserting into the engaging hole 15 and the engaging groove 16 formed in the side frame 2a and the opening / closing member 2b constituting the lens holding cylinder 2. After the moving arrangement, the opening / closing member 2b is attached to the side frame 2a to fix the lens and the diaphragm plate 4, and the side frame (opening / closing lid) 7 is closed to complete the change adjustment.
In addition, when blurring the image, the two lenses can be arranged in such a way that the convex surfaces face each other in addition to the method in which the convex surfaces are both facing backward, or the convex surfaces are both facing forward. Although it is conceivable, it is most preferable to arrange the convex surfaces facing backwards in terms of chromatic aberration and distortion.
That is, the lens configuration can be easily changed by the engagement hole 15 and the engagement groove 16 of the lens holding cylinder 2. As a result, it is possible to change to a lens configuration with a different degree of blur.
Since the lens movement adjustment mechanism for adjusting the focus is composed of a combination of a worm and a rack and pinion, the adjustment state does not change even if the hand is removed from the adjustment knob after the focus adjustment.
[0021]
With the above configuration, the following effects can be obtained.
(1) A bright and clear image can be projected.
(2) There is almost no distortion of the image.
(3) Little chromatic aberration.
{Circle around (4)} Displacement (curvature of field) between the center and the surrounding focus position is improved.
(5) The sharpness and brightness of the image can be changed by changing the middle aperture plate.
(6) Since the lens can be easily taken out, cleaning is easy.
(7) The focus adjustment operability is good (after adjustment, it is not necessary to lock the movement of the lens holding cylinder separately).
(8) A lens configuration with a different degree of blur can be obtained.
[0022]
【The invention's effect】
The projection lens apparatus according to the present invention can easily change the lens configuration according to the configurations of the first to third aspects. In addition, since the lens can be easily taken out, the lens can be easily cleaned.
According to the fourth aspect of the present invention, the number of support points that come into contact with the lens increases, and the lens can be supported more stably.
Further, according to the fifth aspect, even after the focus adjustment, the adjustment state does not change even if the hand is released from the adjustment knob. Therefore, there is no need to provide a separate lens fixing lock mechanism.
Further, according to the sixth aspect of the present invention, the diaphragm plate used for adjusting the projection can be carried with the apparatus, so that the diaphragm plate can be prevented from being lost.
Further, according to the configuration of the seventh aspect, it is possible to provide an effect spotlight system that can change the projection of a sharp image and the projection of a blurred image with a single projection lens device, and has high operability. .
[Brief description of the drawings]
FIG. 1 is a partially cutaway side view showing a spotlight system equipped with a projection lens device according to the present invention.
FIG. 2 is an enlarged cross-sectional view of a projection lens device portion.
3 is an enlarged cross-sectional view taken along line (3)-(3) of FIG.
FIG. 4 is a perspective view showing a state where an opening / closing lid of a protective case is opened and an opening / closing member of a lens holding cylinder is removed.
FIG. 5 is an exploded perspective view in which a lens and a diaphragm plate are removed from the state of FIG. 4;
[Explanation of symbols]
A ... Projection lens device B ... Spotlight C ... Effect machine 1 ... Protective case 2 ... Lens holding 3a-3c ... Plano-convex lens 4 ... Diaphragm plate 5 ... Movement adjustment mechanism 7 ... Open / close lid 15 ... Engagement hole 16 ... Engagement groove 18 ... Holding holding means

Claims (7)

A cylindrical protective case having openings through which light is transmitted on both sides in the axial direction, a lens holding cylinder accommodated in the protective case so as to be movable back and forth along the axial direction, and the lens It consists of a plurality of lenses that are supported in the holding cylinder at a substantially right angle with respect to the axis, the position of the lens being adjustable according to the purpose of blur / clear projection, and the direction in which the lens holding cylinder intersects the axis In addition, an opening / closing lid is provided on the peripheral wall of the protective case so that the lens and the lens holding cylinder opening / closing member can be attached / detached. A projection lens device characterized by the above. 2. The protective case according to claim 1, wherein the protective case is a substantially square cylinder, the lens holding cylinder is a substantially regular octagonal cylinder, and an engagement hole is formed in the peripheral wall of the lens holding cylinder to fit the periphery of the lens. Projection lens device. The lens holding cylinder is composed of two halves, one half is arranged in the protective case so as to be movable back and forth along the axial direction, and the other half is an opening / closing member with one side in the circumferential direction with a spring piece The projection lens device according to claim 1 or 2, wherein the projection lens device is engaged with the movable half and is engaged and disengaged by locking the half on the other side. 4. The projection lens device according to claim 2, wherein the engagement hole formed in the peripheral wall of the lens holding cylinder is a stepped rectangular hole. The projection lens apparatus according to claim 1, wherein the lens holding cylinder forward / backward movement adjusting mechanism is configured by a combination of a worm and a rack and pinion. The projection lens device according to claim 1, wherein a stop plate holding means for a diaphragm plate mounted in the lens holding cylinder is provided inside the opening / closing lid of the protective case. 7. A spotlight, wherein the projection lens device according to claim 1 is detachably attached to a front portion of an effect machine disposed in front of a lamp body.

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