JP4278422B2 - Lens barrel support device and projection display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lens barrel support device that supports a lens barrel movably along a predetermined direction intersecting an optical axis with respect to an optical apparatus body, and a projection display device including the same.
[0002]
[Prior art]
Conventionally, a projector device as this type of projection display device includes a light source that emits illumination light, an LCD panel as light modulation means that modulates illumination light emitted from the light source, and modulation by the LCD panel. A projection lens barrel is provided as a barrel that projects the illumination light as a projection image onto a screen or the like. Some projector apparatuses are provided with a lens barrel support device that enables the position of a projected image to be moved.
[0003]
The lens barrel support device includes a mount portion that supports the projection lens barrel and a linear guide that guides the mount portion in a straight line. The mount portion is connected to a lead screw as a feed screw, and the lead screw is driven to rotate by a motor. Further, the mount portion follows the rotation of the lead screw and is guided by the linear guide to move in the linear direction.
[0004]
The lens barrel support device is provided with an electric switch such as a limit switch or a potentiometer that detects a state in which the mount portion has moved to the end of the moving range. And these electrical switches stop rotation of a motor, when a mount part moves to the edge part of a predetermined movement range.
[0005]
On the other hand, the lens barrel support device is provided with stopper portions that prevent movement of the mount portion at both ends of a predetermined movement range of the mount portion. For example, when the electric switch is damaged, the mount unit can be removed from the shift mechanism such as a lead screw when the motor does not stop despite the mount unit moving to the end of the predetermined movement range. It is prevented from dropping off or moving beyond a predetermined moving range (see, for example, Patent Document 1).
[0006]
[Patent Document 1]
JP 2002-206615 A (page 3-4, FIG. 2 and FIG. 3)
[0007]
[Problems to be solved by the invention]
However, in the above-described lens barrel support device, for example, when the electrical switch is damaged, if the motor continues to be driven in a state where the mount portion is prevented from moving by the stopper portion, the lead screw may be damaged, Or there is a possibility that the motor may be damaged by overload.
[0008]
In this regard, a configuration is conceivable in which double electrical switches are provided and the motor is stopped by the other electrical switch even when one switch is damaged.
[0009]
However, in the case where the electrical switches are used twice, for example, if damage that causes the same cause, such as damage to a common electric circuit, occurs, the two electrical switches may not work together. .
[0010]
For this reason, the above-described lens barrel support device has a problem that the usability is not good.
[0011]
The present invention has been made in view of these points, and an object of the present invention is to provide a lens barrel support device with improved usability.
[0012]
[Means for Solving the Problems]
The lens barrel support device according to claim 1 is a lens barrel support device that supports the lens barrel so as to be movable within a predetermined movement range along a predetermined direction intersecting the optical axis with respect to the optical apparatus main body. A lens barrel side support portion that supports the lens barrel, a feed screw that is provided along a predetermined direction in which the lens barrel moves, and is screwed into the lens barrel side support portion, and the lens barrel side support portion that rotates the feed screw And a sensor that detects the position of the lens barrel side support portion and stops the driving means when the lens barrel side support portion moves to an end of a predetermined movement range. And a predetermined distance outside the predetermined movement range of the lens barrel side support part, and abuts on the lens barrel side support part so that the lens barrel side support part is outside the predetermined movement range by a predetermined distance. a stopper portion for preventing the moving above, is provided between the motor and the feed screw, When the rotation load of the serial motor exceeds a predetermined, by idling the said motor and the feed screw each other, in a state where the stopper portion is in contact with the barrel-side support portion, and the motor is driven, And a clutch mechanism for suppressing transmission of the driving force of the motor to the lens barrel side support portion.
[0013]
In this configuration, in addition to the sensor and the stopper portion, a clutch mechanism that idles the motor and the feed screw when the rotational load of the motor becomes a predetermined abnormality is provided, so that the lens barrel side support portion has a predetermined movement range. Moving outside is reliably prevented, and even when the sensor does not function, the driving means is protected without being overloaded .
[0014]
The lens barrel support device according to claim 2 is the lens barrel support device according to claim 1, wherein the clutch mechanism is a reduction gear meshed with a gear coupled to a feed screw, and the deceleration to the rotating shaft of the motor. gear, rotation load of the motor is that a resilient means for pressing at a predetermined force such that the reduction gear and the rotation axis of the motor when it becomes more than a predetermined idles each other.
[0015]
In this configuration, the clutch mechanism is configured with a relatively simple configuration, and the manufacturing cost is suppressed.
[0016]
The projection display device according to claim 3 is a light source that emits illumination light, a light modulation unit that modulates illumination light emitted from the light source, and a lens barrel that projects illumination light modulated by the light modulation unit. And a lens barrel support device according to claim 1 or 2 that supports the lens barrel movably along a predetermined direction intersecting the optical axis with respect to the optical device body. is there.
[0017]
In this configuration, by providing the lens barrel support device according to claim 1 or 2 , the lens barrel can be moved within a predetermined movement range, and the driving means is excessive even when the sensor does not function. Protected without load.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the configuration of a projection display apparatus according to an embodiment of the present invention will be described with reference to FIGS.
[0019]
In FIG. 2, reference numeral 11 denotes a liquid crystal projector which is a projector device as a projection display device. The liquid crystal projector 11 includes a housing 12 as an optical device main body and a light source 13 that irradiates the housing 12 with light. The liquid crystal projector 11 includes three transmissive LCD panels 14r, 14g, and 14b as liquid crystal display elements serving as light modulation means. Furthermore, a lens barrel 16 that is a projection lens barrel is attached to the casing 12 via a lens barrel supporting device 15 that is a lens barrel moving mechanism. The casing 12, the lens barrel supporting device 15, and the mirror An optical unit is constituted by the cylinder 16 and the like. The optical unit and the light source 13 are covered with an exterior cover 17 as an exterior body. In the exterior cover 17, a fan, a display unit, a power supply device (not shown), a CPU 18 as a control means, a motor drive circuit 19, and a projection lens shift switch 20 as a switch as an operation means are disposed. Has been.
[0020]
The casing 12 is formed of, for example, a synthetic resin, and is configured by a box-shaped main casing in which various illumination optical systems (not shown) are disposed, and a lid that closes an upper opening of the main casing. .
[0021]
The light source 13 includes an incandescent bulb such as a halogen lamp or a discharge lamp such as a metal halide lamp. Around the discharge lamp, a reflector having a parabolic mirror surface for reflecting light emitted from the discharge lamp is disposed.
[0022]
Therefore, the light emitted from the discharge lamp of the light source 13 is reflected by the reflector, passes through the lens array, etc., is color-separated by a dichroic mirror (not shown), and enters the LCD panels 14r, 14g, and 14b. In the LCD panels 14r, 14g, and 14b, incident illumination light is modulated in accordance with a video signal processed by a video signal processing circuit (not shown), etc., color-synthesized by a dichroic cross prism DXP, and projected from a lens barrel 16 onto a screen To do.
[0023]
Hereinafter, with respect to the optical axis of illumination light traveling from the light source 13 toward the screen, the screen side is the front side, the light source 13 side is the rear side, and the first direction intersects or is orthogonal to the optical axis when viewed from the light source 13 side. Will be described as the vertical direction and the second direction orthogonal to the optical axis and the vertical direction as the width direction, that is, the horizontal direction.
[0024]
The lens barrel support device 15 supports the lens barrel 16 so that the lens barrel 16 can be moved, that is, shifted, with respect to the casing 12 along a vertical direction as a predetermined direction. As shown in FIGS. 1 and 3, the lens barrel support device 15 is movably attached to a first mount (not shown) fixedly attached to the main housing side of the housing 12 and the first mount. And a second mount 22.
[0025]
The first mount includes a first main body portion that is a case-side support portion formed in a frame shape with a metal member having a relatively higher rigidity than the synthetic resin, such as a magnesium alloy, and the first mount portion. 1 has a prism mounting portion that protrudes rearward from the lower end portion of the main body portion 1 and is provided integrally, and on which the LCD panels 14r, 14g, 14b and the dichroic cross prism DXP are mounted.
[0026]
The second mount 22 includes a second body portion 31 as a lens barrel side support portion integrally formed in a substantially square frame shape by a member such as a metal such as an aluminum alloy or a synthetic resin. . The second main body 31 can be shifted in the vertical direction, which is a predetermined direction orthogonal to the optical axis, with respect to the first main body of the first mount, and directly or via another member. The lens barrel 16 is supported.
[0027]
A through hole 32 is formed in one side portion in the width direction of the second main body portion 31 along the vertical direction. A cylindrical rod-like vertical movement linearly moving guide 33 serving as a guide portion is formed in the through hole 32. Is inserted. This vertically moving linear guide 33 is fixed to the first mount or the like, and guides or guides the second main body 31 linearly along the vertical direction, so that the shift direction of the second main body 31 is the vertical direction. And protrudes from the upper end portion and the lower end portion of the second main body 31, respectively.
[0028]
Further, in the vicinity of the upper end portion and the lower end portion of the vertically moving linear guide 33, a rectangular upper stopper portion 34 that constitutes a stopper portion that faces the center of the second main body portion 31 in the width direction. And the lower stopper part 35 protrudes and is provided integrally. These upper and lower stopper portions 34 and 35 are respectively provided at positions separated by a predetermined distance D from the vertical movement range of the second main body portion 31. Further, the upper and lower stopper portions 34 and 35 are configured such that when the second main body portion 31 is shifted upward and downward, the upper end portion and the lower end portion of the second main body portion 31 abut on each other. The main body 31 is prevented from shifting beyond a predetermined moving range in the vertical direction by a predetermined distance D or more.
[0029]
In addition, on the other side in the width direction of the second main body 31, that is, on the side opposite to the vertical movement guide 33, the first insertion portion 36 is located at the lower end in the vertical direction. And projecting toward the side of the main body 31. Furthermore, a first screw hole 37 is formed in the first insertion portion 36 along the vertical direction. A feed screw 38 as a lead screw is screwed into the first screw hole 37 and inserted therethrough. That is, the feed screw 38 is provided along the up-down direction that is the shift direction of the second main body 31, and is attached to the second main body 31. Further, a first screw-side reduction gear 39 that is a spur gear as a screw-side power transmission unit is attached to the lower end side that is one end side in the axial direction of the feed screw 38.
[0030]
On the other hand, a motor 41 as a driving means is disposed on the side of the first insertion portion 36, that is, the feed screw 38. The motor 41 is connected to a first screw-side reduction gear 39, that is, a feed screw 38 via a clutch mechanism 44 fixed to a first mount or the like and attached to a rotating shaft 43 protruding downward. The screw 38 is rotated to shift the second main body 31 in the vertical direction.
[0031]
The clutch mechanism 44 includes an intermediate receiving portion 46 fixed to the intermediate portion of the rotating shaft 43, and a tip receiving portion 47 fixed to the distal end portion of the rotating shaft 43. Further, the intermediate receiving portion 46 and the tip receiving portion A motor-side reduction gear 48 that is a spur gear serving as a motor-side power transmission portion that is a gear that is positioned between the motor 47 and rotatably supported on the rotary shaft 43 is provided. Further, the clutch mechanism 44 includes a coil spring 49 as an elastic means that is positioned between the motor-side reduction gear 48 and the tip receiving portion 47 and is mounted on the rotary shaft 43. The coil spring 49 presses the motor-side reduction gear 48 against the intermediate receiving portion 46, and unless an excessive load is applied to the motor-side reduction gear 48, frictional force between the motor-side reduction gear 48 and the intermediate receiving portion 46 is obtained. Thus, the rotating shaft 43 and the motor side reduction gear 48 are rotated together. When an excessive load is applied to the motor side reduction gear 48, the motor side reduction gear 48 and the intermediate receiving portion 46 slide to cause the motor side reduction gear 48 to idle with respect to the rotating shaft 43. .
[0032]
The motor-side reduction gear 48 meshes with the first screw-side reduction gear 39, and transmits the driving force of the motor 41 to the feed screw 38 at a predetermined reduction ratio. The reduction gears 39 and 48 constitute a vertical reduction mechanism. This vertical speed reduction mechanism is provided so that the speed difference between the upward shift and the downward shift of the second main body 31 is reduced.
[0033]
Further, a sensor 51 for detecting a vertical shift position of the second main body 31 is attached between the first main body 31 and the second main body 31. This sensor 51 is a vertical position potentiometer that is a variable resistor, and is electrically connected to a CPU 18 as control means, as schematically shown in FIG. The CPU 18 is connected to a motor drive circuit 19 that controls the drive of the motor 41. Depending on the operation of the projection lens shift switch 20 and the vertical position of the second body 31 detected by the sensor 51, the CPU 18 The drive of the motor 41 is turned on / off through the motor drive circuit 19.
[0034]
On the other hand, the lens barrel 16 is formed in a double cylindrical shape by a cam cylinder and a guide cylinder (not shown) formed of, for example, an aluminum alloy and holding a plurality of lenses therein. The lens barrel 16 rotates the cam cylinder or guide cylinder in the circumferential direction of the lens barrel 16 to change the position of the lens along the optical axis, thereby enabling an image zoom function or focus adjustment (focusing). ) Has a function.
[0035]
Next, the operation of the above embodiment will be described.
[0036]
Illumination light emitted from the light source 13 is split into R (red), G (green), and B (blue) color light in the housing 12, and these R (red), G (green), and B The (blue) color light is incident on the LCD panels 14r, 14g, and 14b, and is modulated by the LCD panels 14r, 14g, and 14b.
[0037]
Further, each color light modulated by the LCD panels 14r, 14g, and 14b is color-synthesized with the synthesized light by the dichroic cross prism DXP, and enters the lens of the lens barrel 16.
[0038]
Then, a projection image is projected from the lens barrel 16 toward a screen (not shown) or the like.
[0039]
Here, when the projection image is shifted vertically with respect to the screen for adjusting the projection position, the motor-side reduction gear 48 is rotated by operating the projection lens shift switch 20 and driving the motor 41. The first screw-side reduction gear 39 engaged with the motor-side reduction gear 48 is rotated, and the feed screw 38 is rotated.
[0040]
As a result, the second mount 22 is shifted in the vertical direction together with the lens barrel 16 relative to the feed screw 38 while being guided in the vertical direction by the vertical movement linear guide 33, and the vertical position of the projected image is changed. Change.
[0041]
In this state, as shown in FIG. 1, the CPU 18 monitors the position of the second main body 31 via the sensor 51, and the second main body 31 is one of the upper and lower ends A and B of the movement range. CPU 18 stops driving of motor 41 by motor drive circuit 19 when it is detected that the motor 41 has been moved to.
[0042]
Here, when the position of the second main body portion 31 cannot be accurately detected due to a failure of the sensor 51 or the like, and the second main body portion 31 moves out of a predetermined movement range, the second main body portion. The stopper portions 34 and 35 are mechanically contacted with 31 to prevent the second main body portion 31 from moving beyond a predetermined distance D.
[0043]
Furthermore, even when the second body 31 is in contact with the stoppers 34 and 35, if the drive of the motor 41 continues to rotate without stopping, a large load is applied to the vertical speed reduction mechanism or the like. become. In this state, if a load (torque) greater than a predetermined value is applied to the clutch mechanism 44, the motor-side reduction gear 48 rotates idly with respect to the rotating shaft 43 of the motor 41, preventing overload from being applied to each part. Each part such as 41 and the first and second mounts 22 can be protected.
[0044]
As described above, in the above-described embodiment, in the lens barrel shift mechanism in which the lens barrel 16 can be moved by being driven by the motor 41, the sensor 51 that is an electrical switch and the mechanical stopper portions 34 and 35 are provided. In addition, since the clutch mechanism 44 is interposed between the motor 41 and the feed screw 38, the sensor 51, which is an electrical switch, breaks down, and the second mount 22 that supports the lens barrel 16 is attached to the stopper portions 34 and 35. Even when the motor 41 continues to operate in the contact state, the overload applied to the motor 41 by the clutch mechanism 44 can be reduced, and an inadvertent force applied to the shift mechanism such as the feed screw 38 can be buffered.
[0045]
Further, since the clutch mechanism 44 is configured to press the gear with the coil spring 49 mounted on the rotating shaft 43 of the motor 41, the clutch mechanism 44 can be configured with a relatively simple configuration, and the manufacturing cost can be suppressed.
[0046]
The stopper portions 34 and 35 are located outside the shift range which is a position away from the end portions A and B which are predetermined stop positions of the lens barrel 16 by the sensor 51, and the clutch mechanism 44 is It is used only when the sensor 51 is out of order. In addition, the positions where the stopper portions 34 and 35 are provided are set at positions slightly away from the end portions A and B which are predetermined stop positions in order to protect the peripheral mechanism from interference due to excessive movement of the mount portion and the like. Yes.
[0047]
In the above-described configuration, the configuration in which the lens barrel 16 is moved only in the vertical direction has been described. However, the configuration is not limited to this configuration, and the configuration in which the lens barrel 16 is moved only in the horizontal direction is provided. And it can also be set as the structure which moves to the left-right direction.
[0048]
In the above configuration, the first insertion portion 36 provided with the first screw hole 37 that is screwed into the feed screw 38 is integrally provided in the second main body portion 31, but is not limited to this configuration. The feed screw 38 can be screwed onto a separate nut that engages with the two main body portions 31.
[0049]
【The invention's effect】
According to the lens barrel support device of the first aspect, in addition to the sensor and the stopper portion, the lens barrel side is provided with the clutch mechanism that idles the motor and the feed screw when the rotational load of the motor becomes a predetermined abnormality. It is possible to reliably prevent the support portion from moving outside the predetermined movement range, and to protect the driving means without overloading even when the sensor does not function .
[0050]
According to the lens barrel support device of the second aspect , in addition to the effect of the first aspect , the clutch mechanism can be configured with a relatively simple configuration, and the manufacturing cost can be suppressed.
[0051]
According to the projection type display device of the third aspect, since the lens barrel support device according to the first or second aspect is provided, the lens barrel can be moved within a predetermined movement range and is also driven when the sensor does not function. It can be protected without overloading the means.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram viewed from the front showing a projection display device according to an embodiment of the present invention;
FIG. 2 is a plan view for explaining the projection display device.
FIG. 3 is an exploded perspective view for explaining a lens barrel support device of the projection display device.
FIG. 4 is an explanatory diagram for explaining the operation of the projection display device.
[Explanation of symbols]
11 Liquid crystal projector as a projection display
12 Enclosure as optical equipment
13 Light source
14r, 14g, 14b LCD panel as light modulation means
15 Lens barrel support device
16 Lens tube
31 Second body as a lens-barrel support
34 Upper stopper part of the stopper part
35 Lower stopper part of the stopper part
38 Lead screw
41 Motor
43 Rotation axis
44 Clutch mechanism
48 Reduction gear on motor side as gear
49 Coil springs as elastic means
51 Sensor A, B End D Predetermined distance

Claims (3)

A lens barrel support device that supports a lens barrel movably within a predetermined movement range along a predetermined direction intersecting the optical axis with respect to the optical device body,
A lens barrel-side support for supporting the lens barrel;
A feed screw provided along a predetermined direction in which the lens barrel moves and screwed into the lens barrel side support portion;
A motor for rotating the feed screw to move the lens barrel side support portion along the predetermined direction;
A sensor that detects the position of the barrel-side support portion and stops the driving means when the barrel-side support portion moves to an end of a predetermined movement range;
The lens barrel side support portion is provided at a position outside a predetermined distance from the predetermined movement range of the lens barrel side support portion, and comes into contact with the lens barrel side support portion so that the lens barrel side support portion moves outside the predetermined movement range by a predetermined distance or more. A stopper to prevent
Provided between the motor and the feed screw, and when the rotational load of the motor exceeds a predetermined value, the stopper portion is supported on the lens barrel side by causing the motor and the feed screw to idle each other. A lens barrel support device comprising: a clutch mechanism that suppresses transmission of the driving force of the motor to the lens barrel side support portion in a state where the motor is in contact with the motor portion . The clutch mechanism
A reduction gear meshed with a gear connected to the feed screw;
The reduction gear to the rotary shaft of the motor, the rotation load of the motor and an elastic means for pressing at a predetermined force to the rotation shaft of the motor when it becomes more than a predetermined and said reduction gear idles each other The lens barrel support device according to claim 1, further comprising: A light source that emits illumination light;
A light modulation means for modulating the illumination light emitted from the light source;
A lens barrel for projecting illumination light modulated by the light modulation means;
An optical device body;
3. A projection type display device comprising: the lens barrel supporting device according to claim 1 or 2 , wherein the lens barrel is movably supported along a predetermined direction intersecting the optical axis with respect to the optical apparatus main body. .

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