JP2003057750A - Lens elevating mechanism and optical device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lens elevating mechanism and an optical device using it, of which the assemblability to a chassis, the maintainablity, etc., are improved by unitizing each function part as much as possible. SOLUTION: The lens elevating mechanism adjusts the vertical position of a lens body 5, which is attached to a mobile frame 4, to a chassis 3 of a device through the mobile frame 4 and is provided with a lens unit LU and a driving unit 7, and the lens unit LU has a connection part 47 projecting to one side together with a lens body 5 and the mobile frame 4 and is vertically movably supported on the chassis 3 through a guide means, and the driving unit 7 which is attached to one side of the chassis 3 and has at least a motor 85 and a spiral shaft 80 turned by the driving force of the motor. The connection part 47 is spirally connected with the shaft 80 to elevate the lens unit LU along the shaft 80.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens elevating mechanism for vertically adjusting a lens body and an optical device using the same.

[0002]

2. Description of the Related Art FIG. 7 is a schematic view of a liquid crystal projector as seen from the front side. This projector 1 supports a projection lens 5 so as to be able to move up and down through a movable frame 4 with respect to a chassis 3 which is built in a housing 2 and in which a liquid crystal panel, a circuit system and the like are arranged. The projection lens 5 is attached to the housing 2
It is exposed through a relatively large opening 2a provided in the, and the vertical position is adjusted via the movable frame 4. By the way, such an elevating mechanism for a movable frame for a lens is disclosed in, for example, Japanese Patent Laid-Open Nos. 5-273245 and 6-33739. The former supports the movable frame on a pair of screw shafts, and rotates one of the shafts through the meshing of bevel gears to move the movable frame up and down along the shaft. The latter one supports the movable frame on the shafts on both sides provided on the chassis so that it can move up and down,
Further, the movable frame is moved up and down through the meshing of a rack provided on one side of the movable frame and a pinion supported on the chassis side.

[0003]

In any of the above structures, the movable frame is manually moved up and down, but as the function is improved, the movable frame is automatically moved up and down by the driving force of the motor built in the housing. It is also being realized. In that structure, for example, a support mechanism for a movable frame and a drive mechanism such as a motor are assembled to the chassis while cooperating with each other, or a position sensor for detecting the position of the movable frame and controlling the motor based on the detected value. Since it is also directly attached to the chassis, the assembly workability is extremely poor and an increase in manufacturing costs cannot be avoided. From such a background, there is a strong demand for a lens elevating mechanism that is more rational and can improve the number of assembling steps to some extent.

The present invention was developed to solve the above problems. The purpose is to improve the assembly and maintenance of the chassis by making each functional unit as much as possible, and to promptly respond when the inspection fails during the assembly. An object of the present invention is to provide a lens elevating mechanism and an optical device using the same, which can significantly reduce the cost.

[0005]

In order to achieve the above object, the present invention has a lens body 5 attached to a movable frame 4 as illustrated in the drawings, and a chassis 3 of equipments through the movable frame 4.
On the other hand, in the lens elevating mechanism for adjusting the vertical position, the lens body 5 and the movable frame 4 have a connecting portion 47 protruding from one side of the movable frame, and the chassis 3 is provided with guide means (for example, a shaft 48 and a support). Part 46, guide member 49
And a lens unit LU which is vertically movably supported via a guide piece 45), and a helical shaft 80 which is attached to one side of the chassis 3 and is rotated by at least a motor 85 and a driving force of the motor. Drive unit 7
It is characterized in that the lens unit LU is moved up and down along the shaft 80 by screwing and connecting the connecting portion 47 to the shaft 80.

According to the above-described lens elevating mechanism, in assembling devices, the lens unit LU and the drive unit 7 are individually attached to the chassis 3, and then the connecting portion 4 is used.
7 can be screwed and connected to the shaft 80. Therefore, with this structure, the assembly procedure can be simplified, the complexity can be eased, and the assembly workability can be improved. Further, for example, the drive unit 7 can be inspected independently, and the chassis 3
It is also easy to maintain because it is guaranteed to be removed independently. Moreover, since such a drive unit 7 can also include other functional parts such as the board 75 and the position sensor 77 as in the embodiment, many items that can be inspected before assembling to the chassis 3 are increased, and the drive unit 7 can be used in the assembly line. It is easy to improve the yield. Further, because the motor 85 is arranged in the drive unit 7, it is easy to prevent vibrations generated during motor driving from being transmitted to the chassis 3 side as much as possible. Therefore,
This lens elevating mechanism is suitable for an optical device as recited in claim 6.

The present invention as described above is more preferably embodied as claimed in claims 2 to 5. First, the drive unit 7 has a moving member 78 that is screwed onto the shaft 80 and is engaged and connected to the connecting portion 47 of the lens unit LU. This is because the connecting portion 47 of the movable frame 4 is connected to the shaft 80 via the moving member 78, so that it is less likely to be restricted by the arrangement of the lens unit LU and the drive unit 7 and the degree of freedom in design can be increased. . -Secondly, the drive unit 7 is configured to be attached to the attachment portion 34 provided on one side of the chassis 3 via the gear box 71 in which the motor 85, the shaft 80 and the like are assembled. This is because the drive unit 7 has a gearbox 71, through which the chassis 3
It is a confirmation that the points attached to the side are specified. Thirdly, a configuration is provided that includes a protrusion 79 provided on the connecting portion 47 of the lens unit LU or the moving member 78, and a position sensor 77 that is assembled to the gear box 71 and detects the protrusion 79. Is. This is because when the lens unit LU is automatically moved up and down by the driving force of the motor 85, it is necessary to detect the position of the movable frame 4 and control the motor 85, but the position sensor 77 is attached to the gear box 71. Then, the inspection of the drive unit 7 can be performed including the performance inspection of the position sensor 77. -Fourth, the drive unit 7 includes the gear box 7
The shaft 80 is rotated via the worm gear 86 mounted on the output shaft of the motor 85 and the helical gear 81 meshed with the worm gear. This is the motor 85
In addition to clarifying the structure for transmitting the driving force to the shaft 80, the worm gear 86 and the helical gear 81 are also arranged in the gear box 71 to be unitized.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a main part of a liquid crystal projector to which the lens elevating mechanism of the embodiment is applied. FIG. 1A is a partially cutaway front view of the liquid crystal projector in a state where the projection lens is not attached to a movable frame. FIG. 6B is a front view showing a state where the projection lens is attached to the movable frame and moved upward. FIG. 2 is a configuration diagram viewed from above and from the left and right in the mode of FIG. 1A, and FIG. 2A is a partial top view in which a part is broken in the state viewed from above,
The same (b) is a partial left side view, and the same (c) is a partial right side view. 3 is a schematic external view of a main part of a liquid crystal projector in which a projection lens is fixed to a moving frame, and FIG. 4 is a schematic exploded view of the main part of FIG. FIG. 5 is an external configuration diagram showing the lens elevating mechanism, FIG. 6 is an exploded configuration diagram of the lens elevating mechanism, and FIG. 7 is an explanatory diagram that schematically shows the projector. In the following description, first, a portion of the projector related to the present invention will be outlined, and then the detailed structure, assembly, and main operation of the lens elevating mechanism will be described in detail.

(Outline) A projector 1 shown in the figure has a substantially L-shaped chassis 3 covered with a housing 2, and a light source lamp, a liquid crystal panel, a circuit system, etc. are arranged on a horizontal wall 31 of the chassis 3. At the same time, the lens unit RU having the projection lens 5 fixed to the movable frame 4 and the drive unit 7 for moving the lens unit RU up and down are attached to the vertical wall 32, respectively.
Is exposed from the opening 2a of the housing 2. here,
The basic mechanism of the projector 1 is, for example, JP-A-6-33.
Same as those disclosed in 7394 and Japanese Patent No. 2578695. The different points are the lens unit RU and the drive unit 7, and the structure of the vertical portion 32 side of the chassis 3 to which these units RU, 7 are attached. The lens elevating mechanism of the present invention is composed of the lens unit RU and the drive unit 7.

Of these, in the chassis 3, the horizontal wall 31 is schematically illustrated, and the vertical wall 32 is a portion for supporting the lens unit LR. An opening 33 is provided in the vertical wall 32, and the upper and lower flange portions 35a and 35b and the flange portions 3 on both sides are formed.
5c and 35d are provided. A shaft 48 is vertically arranged on one side of the collar portions 35a and 35b via mounting holes 36a and 36b. The shaft 48 has a small diameter portion 48 at the lower end.
a, and a circumferential groove 48b is formed at the upper end. Guide members 49 with vertical grooves are attached to the upper and lower portions of the collar portion 35c by screws 39a. Tsubabe 3
5d, as shown in FIG. 4, a lower step 37 and a mounting piece 34 projecting upward and outward are provided. The step 37 is a place where the corresponding portion of the drive unit 7 is released, and the attachment piece 34 forms an attachment hole 34a for detachably attaching the drive unit 7.

(Lens Unit) Lens Unit RU
Is a projection lens 5 as a lens body attached to the movable frame 4 via a lock device 6. The movable frame 4 is arranged with a margin with respect to the vertical portion 32, and has an opening 41 that always fits in the opening 33 when vertically moved and an upper and lower flange portions 42.
It has a and 42b and collar parts 42c and 42d on both sides. A mounting hole 41a for mounting the lock device 6 on the inner surface
And the four mounting seats 4 serving as reference surfaces for the projection lens 5.
3 and two pins 44 for positioning the projection lens 5 are projected. Two mounting holes 41a are provided close to the collar portions 35c and 35d. The mounting seat 43 has an opening 41
The pins 44 are located on the upper and lower sides and on the left and right sides, and the pins 44 are close to the upper and lower mounting seats 43. Guide pieces 45 are provided on the upper and lower sides outside the flange portion 42c. A support portion 46 forming a fitting hole 46a and a connecting portion 47 projecting between the support portions 46 are provided outside the flange portion 42d. A metal bearing (not shown) is installed in the fitting hole 46a. The connecting portion 47 is formed in a U shape or a U shape,
The shaft 80 of the drive unit 7, which will be described later, can be engaged. In the movable frame 4 described above, the guide pieces 45 are fitted into the corresponding vertical grooves of the guide member 49, and the support portions 46 are provided.
Is supported in the collar portions 35a to 35d so as to be vertically slidable via a shaft 48 that is inserted into the fitting hole 46a in a skewered shape. Therefore, the guide piece 45 is the guide member 49 described above.
And constitute the guide means, and the shaft 48 constitutes the guide means together with the support portion 46. The shaft 48 is
The lower end is held between the collar portions 35a and 35b by an E ring 38 (see FIG. 1) whose lower end engages with the small diameter portion 48a and the mounting hole 36b and whose upper end engages with the circumferential groove 48b.

On the other hand, although the projection lens 5 is schematically illustrated in the drawing, a lens barrel 52 holding a lens system 51 is provided.
And a mounting flange portion (mount) 53 fixed to the lens barrel 52, and a reference hole 54 provided in the flange portion 53 and engaged with the positioning pin 44 described above. The projection lens 5 is detachably fixed to the movable frame 4 by a lock device 6. This locking device 6
Although not shown in detail, a supporting member 60 having a pair of legs is rotatably provided between both legs via a pivot, and is in a non-locking position substantially fitted between both legs. , And an anchor member 63 which is projected from between the leg portions and is switched to a locking position where the flange portion 53 is pressed and locked to the inner surface side of the movable frame 4, and the anchor member 63 is biased toward the locking position. The urging member 10 and the supporting member 60 are provided with an operating member 67 that is assembled to the supporting member 60 and that can switch the anchor member 63 between the locking position and the non-locking position by a pressing operation from the front. In addition, the operating member 67 has operating portions on both sides of the pivot that is pivotally supported by the support member 60, and switches the anchor member 63 between the locking position and the non-locking position by selecting the operating portion. It is like this. Therefore, when fixing the projection lens 5, the anchor member 63
With the flange 53 in the non-locking position,
4 is positioned on the mounting seat 43 through the engagement of the pin 4 and the pin 44, and then the operation member 66 is pushed to operate the anchor member 6
The urging force of the urging member 10 rotates the urging member 3 from the non-locking position toward the locking position. Then, the tip end side of the anchor member 63 is locked to the upper edge or the like of the flange portion 53 (to sandwich the flange portion with the mounting surface), and the flange portion 53 responds to the biasing force of the biasing member 10. It is locked and fixed to the movable frame 4 side with strength. When removing the projection lens 5, the operation member 66 is pushed to switch the anchor member 63 to the unlocked position against the biasing force of the biasing member 10.
Substantially enters between the both leg portions, and releases the restriction on the flange portion 53. Therefore, in the lens unit LD described above, for example, the movable frame 4 may be assembled to the vertical wall 32, and then the lens body 5 may be retrofitted or replaced easily.

(Drive Unit) The drive unit 7 is shown in FIG.
As shown in FIG. 6, a motor 85 driven by an external power source to the gear box 71, a worm gear 86 rotated by the motor 85, a helical gear 81 meshing with the worm gear 86, and a helical gear 81 are integrated. Male screw 8
A shaft with 1a (that is, a spiral shaft) 80,
The moving member 78 screwed with the shaft 80 and the substrate 75.
It is a unit by assembling and.

The gear box 71 is made of a resin molded product,
A back surface portion 71a with a mounting hole 71b attached to the mounting piece 34, a motor housing portion 71c provided below the back surface portion 71a, an outer wall portion 71d and upper and lower wall portions located in front of the back surface portion 71a. In this case, a space portion 71g and the like partitioned by 71e and 71f are formed. Outer wall 71d
Is provided with two positioning pins 71h (see FIG. 2), two engaging pieces 71j with a claw portion formed at the tip thereof, and one supporting column 71k with which a board 75 is mounted.
Further, it has a slit 71m provided in the vertical direction. A shaft insertion hole 71n is provided coaxially in the upper and lower wall portions 71e and 71f. The moving member 78 is
The upper and lower flange portions 78a are provided, and the connecting portion 4 is provided therebetween.
7 is engaged, and a projection 79 is integrally formed on the outer circumference. A male screw 80a of the shaft 80 is provided on the inner circumference.
A female screw 78b that is screwed with is formed. Board 75
Forms a mounting hole 76a corresponding to the column 71k and a positioning hole 76b that engages with the pin 71h, mounts the upper and lower position sensors 77, and connects each position sensor 77 and the contact portion of the motor 85 to a conduction circuit. And an external connection portion. The position sensor 77 is composed of a proximity sensor or the like, and detects the vertical position of the lens unit LU, that is, the movable frame 4 via the protrusion 79, and makes it possible to control the driving force of the motor 85 and the like.

(Assembly) The motor 85 has a worm gear 86 mounted on the output shaft thereof, and is inserted into the accommodating portion 71c and fixed by the screw 39d (see FIG. 1). At this time, the worm gear 86 is arranged on the front side (the lower side of the space portion 71g) from the accommodation portion 71c through a through hole (not shown). Reference numeral 87 is a lead wire connected to the terminal of the motor 85, and is joined to the corresponding portion of the substrate 75. The shaft 80 is
The lower end is fixed to the center of the helical gear 81, and the upper end is inserted into the hole 71n of the lower wall portion 71f, the space portion 71g, and the hole 71n of the upper wall portion 71e. It is assembled by being prevented from coming off via 83 and the E ring 84. At this time, the helical gear 81 is meshed with the worm gear 86. At the same time, the moving member 7
8, the female screw 78b is screwed into the male screw 80a portion of the shaft 80, and the protrusion 79 is arranged outside from the slit 71m. The board 75 has a positioning hole 76b and a pin 71h.
Is engaged with and held by and is fixed to the pillar 71k through a groove 39e. Then, the protrusion 79 is arranged between the upper and lower position sensors 77.

(Operation) In the drive unit 7 assembled as described above, the gear box 71 is attached to the attachment piece 34 of the chassis 3 with the screw 39b (see FIG. 6). As for the mounting time, the above-mentioned lens unit L
It does not matter whether R or the movable frame 4 is attached to the chassis 3 or before. In the former case, when fixing the gear box 71 with a screw, the connecting member 4 is attached to the moving member 78.
Engage 7 In the latter case, when the movable frame 4 is supported on the vertical wall 32 via the shaft 48 and the support portion 46 and the guide member 49 and the guide means of the guide piece 45, the connecting portion 47 is engaged with the moving member 78. Therefore, this structure realizes the following basic advantages. First, in the assembly line of the projector 1, the lens unit LU or its movable frame 4 and the drive unit 7 can be assembled to the chassis 3 at any stage. Of course, the projection lens 5
Can be easily attached to the movable frame 4 via the locking device 6 at any stage. Therefore, structurally, it is possible to greatly relax restrictions and restraints in the assembly procedure. In addition, the drive unit 7 has the position sensor 7 before it is assembled to the chassis 3.
7, the drive of the motor 85 and the drive transmission system can be inspected, so that the inspection items after being attached to the chassis 3 can be halved, or the inspection after the final assembly, that is, the yield improvement can be contributed.

Here, the drive unit 7 includes a motor 8
When the rotational force of 5 is transmitted to the shaft 80 via the worm gear 86 and the helical gear 81 and the shaft 80 is normally or reversely rotated, the moving member 78 screwed to the shaft 80.
The movable frame 4 or the lens unit LU, which is connected to the moving member 78 via the connecting portion 47, is moved up or down along the shaft 80. The function is to adjust the position of the projection lens 5 up and down through the movable frame 4 to change the center position of the projection lens 5 with respect to the liquid crystal panel or the like provided on the horizontal wall 31, and to project the projected image on the screen. The position of is changed. By the way, each functional unit
Higher performance and higher quality are being pursued so that clearer images can be obtained, and the number of inspection items is increasing proportionately. In this structure, the projection lens 5 can be easily replaced via the lock device 6 in the case of inspection failure or maintenance at the final stage of assembly, and the entire drive unit 7 can be easily replaced by attaching / detaching the gear box 71. You can When the lens unit LU is automatically moved up and down, the liquid crystal panel or the like mounted on the horizontal wall 31 is affected by the slight vibration generated by the motor 85. In this structure, the motor 85 is housed in the gear box 71, and
By arranging the mounting piece 34 provided on the side portion of the vertical wall 32 via the gear box 71, the vibration is designed to be transmitted to the liquid crystal panel side which is the heart portion as much as possible. Further, conventionally, the lead wire connected to the motor 85 and the position sensor 77 is long, and the lead wire is often entangled in the housing 2. In this structure, the motor 85 and the board 75 are arranged in the gear box 71 of the drive unit 7, and the position sensor 77 is mounted on the board 75, whereby the lead wire 87 of the motor 85 is shortened or the position sensor 77 is installed. It is designed to eliminate the above-mentioned problems of the conventional lead wire by mounting and wiring the lead wire between the lead wire and the like on the substrate 75.

The present invention is not limited to the above embodiment, but can be variously modified within the scope of the requirements specified in the claims. For example, the projection lens 5 may be another lens system, or the connecting portion 47 of the movable frame 4 may have a female screw structure so as to be directly screwed into the male screw 80a of the spiral shuff 80. It doesn't matter.

[0019]

As described above, the lens elevating mechanism of the present invention has a structure in which a movable frame or a lens unit, which is supported by a chassis so as to be vertically movable, is moved up and down by a motor. Since they can be individually attached to the chassis, and then the connecting portion can be screwed and connected to the shaft, restrictions on the assembly procedure can be eliminated, and complexity can be eased to improve assembly workability and maintainability. At the same time, the drive unit can increase the number of items that can be inspected before it is assembled to the chassis, which can contribute to improving the yield in the assembly line of equipment.
An optical device using this can reduce the number of assembling steps and manufacturing cost, and is excellent in maintainability.

[Brief description of drawings]

FIG. 1 is a front view of a main part of an optical device to which the present invention is applied.

FIG. 2 is a configuration diagram of a main part of the apparatus shown in FIG.

FIG. 3 is a schematic external view of a main part of the optical device.

FIG. 4 is an exploded view of the main part of the optical device.

FIG. 5 is a schematic external view showing a drive unit of the main part of the optical device.

FIG. 6 is a detailed block diagram of the drive unit of FIG.

FIG. 7 is a schematic view of the appearance of the entire optical device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Projector (corresponding to an optical device, 2 is a housing) 3 ... Chassis (31 is a horizontal wall, 32 is a vertical wall, 34 is a mounting portion or a mounting piece) 4 ... Movable frame (46 is a supporting portion, 47 is a connecting portion) ) 5 ... Projection lens (corresponding to a lens body, 53 is a mounting flange portion) LU ... Lens unit 6 ... Lock device 7 ... Drive unit 48 ... Guide shaft (guide means) 45 ... Guide piece (guide means) 49 ... Guide member (guide means) 71 ... Gear box 75 ... Substrate 77 ... Position sensor 78 ... Moving member (79 is a protrusion) 80 ... Helical shaft (80a is a male screw) 81 ... Helical gear 85 ... Motor 86 ... Worm gear

Claims (6)

[Claims] 1. A lens elevating mechanism in which a lens body is attached to a movable frame, and a vertical position of the lens body is adjusted with respect to a chassis of devices via the movable frame, the lens body and the movable frame being provided on one side of the movable frame so as to project. A lens unit having a connecting portion and vertically movably supported by the chassis via guide means; and a spiral shaft attached to one side of the chassis and rotated by at least a motor and a driving force of the motor. And a drive unit having, by screwing and connecting the connecting portion to the shaft,
A lens lifting mechanism, wherein the lens unit is moved up and down along the shaft. 2. The lens elevating mechanism according to claim 1, wherein the drive unit has a moving member that is screwed to the shaft and is engaged and connected to a connecting portion of the lens unit. 3. The lens elevating mechanism according to claim 1, wherein the drive unit is attached to a mounting portion projecting on one side of the chassis via a gear box in which the motor, the shaft and the like are assembled. 4. The lens elevating / lowering device according to claim 3, further comprising a protrusion provided on the connecting portion of the lens unit or the moving member, and a position sensor attached to the gear box to detect the protrusion. mechanism. 5. The drive unit is arranged at a corresponding portion of the gear box, and rotates the shaft via a worm gear mounted on an output shaft of the motor and a helical gear meshed with the worm gear. The lens elevating mechanism according to claim 3 or 4. 6. An optical device comprising the lens elevating mechanism according to claim 1 in a chassis built in a housing.