JP2017068179A - Lens shift mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens shift mechanism capable of performing lens shift with a small force to thereby prevent degradation in resolution such as image plane tilt.SOLUTION: The lens shift mechanism includes: a projection lens; a guide member that holds the projection lens and is movable in a linear direction with respect to an optical axis; a base member holding the guide member; and a holding member for preventing the guide member from being pulled out in an optical axial direction with respect to the base member. The lens shift mechanism has a structure in which after placing the guide member on the base member, the holding member is assembled from the top thereof. The holding member is arranged to be smaller at the front side in an assembling direction.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a projector, and more particularly to lens shift.

  Conventionally, as a lens shift mechanism of a liquid crystal projector, ones as disclosed in Patent Document 1 and Patent Document 2 have been proposed. Patent Document 1 is a type that shifts a shift plate by a general spring, and there is no backlash in the shift plate, and image plane tilt of the projection lens does not occur. On the other hand, Patent Document 2 is a guide bar system, which has a low frictional force between the guide bar and the sleeve portion and is excellent in slidability, and operates with a slight force.

JP 2010-97019 A JP 2005-173460 A

  However, each of the conventional examples has problems. In Patent Document 1, a large frictional force is generated in the sliding portion due to the biasing force by the spring, and there is a problem if the shift movement such as hooking and swell is hindered. In addition, Patent Document 2 moves very smoothly with no catch, but has a backlash between the guide bar and the sleeve, and thus has a problem when the image performance of the projection lens changes due to normal driving or posture change. . No matter which method is used, problems remain.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a lens shift mechanism that can suppress an increase in frictional force while having a side-by-side structure in order to ensure image performance of a projection lens.

In order to achieve the above object, the present invention provides:
A projection lens, a guide member that holds the projection lens and moves in a direction perpendicular to the optical axis, a base member that holds the guide member, and a holder that prevents the guide member from slipping out of the base member in the optical axis direction A lens shift mechanism having a member, wherein the guide member is overlapped on the base member and the holding member is assembled thereon, and the holding member has a small front end side in the assembling direction; By doing so, it is possible to suppress an increase in frictional force while having a one-sided structure.

  According to the lens shift mechanism of the present invention, the shifting force acts on the portion that slides with the shift plate by its own weight, and the image performance of the projection lens does not deteriorate. Furthermore, the frictional force is small because it is a force of its own weight regardless of the justified state, and movements that cause problems such as catching and swell are not generated when it is moved. Good movement can be obtained while removing the backlash by displacing. This is maintained not only in the vertical direction but also in various states such as the horizontal direction and the ceiling.

Perspective view of shift unit and projection lens unit Front view of shift unit and projection lens A1-A1 cross section Partial enlarged view of A1-A1 cross section AB-B1 cross section Partial enlarged view of B1-B1 cross section B2-B2 cross section Partial enlarged view of B2-B2 cross section CC cross section Ceiling-mounted shift unit and projection lens front view (cross-sectional line) D1-D1 cross section D1-D1 cross section enlarged view Shift unit and projection lens front view showing Example 2 Shift unit and projection lens front view showing Example 3 EE cross section

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view according to an embodiment of the present invention.

  Reference numeral 1 denotes a projection lens unit that magnifies and projects an image formed inside the projector apparatus. Reference numeral 2 denotes a shift plate A that moves to the left and right, and holds one projection lens unit. 3 is a shift plate B, which moves up and down with 2 shift plates A and 1 projection lens unit. Reference numeral 4 denotes a fixed plate, which is fixed to the projector main body, and holds all the components constituting the shift unit directly or indirectly.

  Reference numeral 5 denotes a nut, which is a component that transmits the rotational force of a screw, which will be described later, to the shift plate. 6 has a screw shape on the outer periphery of the screw A, and the nut of the 5 has a screw shape which is opposed to the screw. The rotation of the screw A of 6 causes the shift plate A of 2 to move in the left-right direction. Moving. Reference numeral 7 denotes a dial A, which is directly connected to the screw A of 6, and is a part that is manually operated by the user. Reference numeral 8 denotes a bearing A, which is fixed to a fixed plate 4 and rotates and holds a screw A 6.

  Reference numeral 9 denotes a screw B having a screw shape on the outer periphery, and the nut 5 has an opposite screw shape. When the screw B of the 9 is rotated, the shift plate B of 3 is vertically moved. Moving. Reference numeral 10 denotes a dial B, which is directly connected to the screw B 9 and is a part that is manually operated by the user. Reference numeral 11 denotes a bearing B, which is fixed to a fixed plate 4 and rotates and holds a screw B 9.

  A screw L is a member for fixing the projection lens unit 1 to the shift plate A 2. 13 is a taper roller, and 14 is a screw T. 13 taper rollers and 14 screws T hold 2 shift plates A to 3 shift plates B. The second shift plate A is movable to the left and right with respect to the third shift plate B. Similarly, the third shift plate B is movable up and down in the optical axis direction with respect to the four fixed plates.

  Reference numeral 15 denotes a restricting piece B, which is fitted so as to sandwich the 3b portion of the three shift plates B, but is movable in the left-right direction with respect to the three shift plates B. 16 is a screw P and 17 is a ball plate. 17 ball plates for holding 18 balls, which will be shown later, are fixed to 4 fixing plates with 16 screws P.

  Hereinafter, the configuration and effects of the first embodiment of the present invention will be described with reference to FIGS.

  In FIG. 1, when the user turns 7 dial A, 6 screw A rotates and 5 nut tries to rotate. However, the 2 shift plate A is moved in the axial direction of the screw A by restricting the rotation of 5 at the portion 2c. If the user turns the dial B, the screw 9 rotates and the nut 5 tries to rotate. The 5 shift plates B are moved in the axial direction of the screws B by restricting the rotation of the 5 nuts at the portion 3b.

  FIG. 2 is a view seen from the front, and is a view for explaining a cross-sectional position of a cross-sectional view described later. FIG. 3 shows an A1-A1 cross section.

  The 1 projection lens and the 2 shift plate are fixed by 12 screws L, and are thus integrated, and are held by the 3 shift plate B in a relatively movable state. In contrast to the shift plate B of 3, the shift plate A of 2 is combined with holes and pins. 13 taper rollers are fitted into this, and it is incorporated so as not to come off with 14 screws T.

  FIG. 4 is an enlarged view of the part (A) and the part (B) shown in FIG.

  The weight F of 1 projection lens is applied to the 2a portion of the shift plate A of 2, and this weight F is applied to the 13a portion which is the taper portion of the upper taper roller. As a result, the shift plate A tends to slide along the portion 13a, so that a weight is applied in the direction of arrow C. As a result, the shift plate B is shifted to the 3a portion which is the sliding portion. Since the center of gravity of the projection lens is at the position of arrow F, the shift plate A generates a rotational moment counterclockwise around arrow C. As a result, the lower side of the shift plate A is brought into contact with the sliding portion 3b of the shift plate B and is shifted in the direction of arrow R. From the relationship between the center of gravity and the taper roller, as a result, the shift plate A is in a state of being shifted to the shift plate B.

  4A, the taper portion 2a of the shift plate A is in contact with the upper portion 13a of the 13 taper roller, but the lower side of the taper roller is not in contact. FIG. 4B also shows that the 13 tape rollers and the shift plate A are not in contact with each other and are not in a double fit. Although the shift plate A is held so as to move in the horizontal direction, even if the dial 7 is rotated, the frictional force is smaller than the force F, so that the shift plate A moves smoothly without rattling. The shift plate A and the shift plate B are shifted together without play and the image plane of the projection lens is always kept constant. This is the same in the A2-A2 cross section, and the image performance of the projection lens is kept good.

  FIG. 5 shows a B1-B1 cross section, in which a vertically moving shift plate B is held so as to be movable relative to three fixed plates. Since it is a horizontal cross section, it is a view from above. This is a state in which the weight of one projection lens is hung on the back of the paper. Then, the weight of the object held by the shift plate B is applied to the taper roller on the lower side of the paper surface of the cross section B1-B1, and is shifted to the arrow L direction.

  As shown in FIG. 6 (A), the 3 shift plates B are not in contact with the 13 tape rollers. On the other hand, the portion 13a and the portion 2a in FIG. 6 (B) are in contact with each other, and the force works and contacts only in the G direction. Similarly, FIG. 7 shows a B2-B2 cross section, and shows that the weight of the projection lens, the shift plate A, and the shift plate B is applied in the direction of the arrow R of the taper roller on the lower side of the drawing. Yes.

  As shown in the enlarged view of FIG. 8, the shift plate A of 2 is not in contact with the taper roller of part (A), but the force of arrow H acts on the taper surface on the upper part of part (B). Because it is in contact. This is because the force F acts on the two tape rollers because of the weight F of the projection lens, and as a result, the shift plate B is offset to the fixed plate. However, this is an action that works only on the taper roller on the right side of the paper in FIG. 2, and no shifting action on the left side. Therefore, the left side of FIG. 2 is pressed by 17 ball plates via 18 balls as shown in the CC cross section of FIG. The 18 balls are provided in two places, and when the shift plate B of the 3 moves in the vertical direction, the frictional resistance is changed to a rolling resistance, so that a very small sliding resistance is sufficient. As a result, the shift plate B can be shifted to the fixed plate without play.

  FIG. 10 shows a suspended state of the shift unit of FIG. 3 and a cross-sectional line. FIG. 11 shows a D1-D1 cross section, in which the shift plate A is offset by the force in the direction of arrow J and the force in the direction of arrow K. This is the same state as in FIG. 3 except that the top and bottom are interchanged. Fig. 12 shows the abutting relationship with 13 tape rollers in an enlarged manner, but the force in the J direction indicated by the arrow is acting on the upper side of (A) expansion, and (B) is There is no contact, and only the force in the direction of the arrow K is working. Thereby, even if it is a ceiling-suspended state, the shift plate A can be shifted to the shift plate B only by reversing the position where it abuts in the backlash range. The shift plate 3 is in contact with the fixed plate.

  From the above, using the weight of the projection lens 1, a structure is realized in which the shift plate 2 is shifted to the shift plate 3 and the shift plate B is shifted to the fixed plate 4. Further, the applied frictional force can be reduced, and there is a great advantage if the state is not caught or swelled during the shift drive.

  FIG. 13 shows a second embodiment. Since the symbols are the same as those in the first embodiment, description thereof is omitted.

  Although the shift plate 2 can be moved left and right by turning the dial 7, the method of holding the shift plate A is the same as that described with reference to FIG. 3. This indicates that the present invention can be implemented with only a shift unit that can move in the horizontal direction.

  FIG. 14 shows a third embodiment. Since the symbols are the same as those in the first embodiment, description thereof is omitted.

  By turning the 10 dial, the 3 shift plates B are moved up and down, but the method of holding the shift plate B is the same as that explained with reference to FIG. This indicates that the present invention can be implemented with only a shift unit movable in the vertical direction.

1 projection lens unit, 2 shift plate A, 3 shift plate B, 4 fixing plate, 5 nut,
6 Screw A, 7 Dial A, 8 Bearing A, 9 Screw B,
10 Dial B, 11 Bearing B, 12 Screw L, 13 Taper piece, 14 Screw T,
15 Restriction piece B, 16 Screw P, 17 Ball plate, 18 balls

Claims (4)

A projection lens;
A guide member that holds the projection lens and moves in a direction perpendicular to the optical axis;
A base member for holding the guide member;
In the lens shift mechanism having a holding member that prevents the guide member from slipping out in the optical axis direction with respect to the base member,
A lens shift mechanism characterized in that the guide member is stacked on the base member and the holding member is assembled thereon, and the holding member has a small front end in the assembling direction. 2. The lens shift mechanism according to claim 1, wherein the holding member is an inclined surface that becomes smaller on a front end side in an assembly direction. 2. The lens shift mechanism according to claim 1, wherein the holding member is an inclined surface whose front end side in the assembly direction becomes smaller, and the inclined surface is an inclined surface having an inclination of 45 ° with respect to the optical axis.   The lens shift mechanism according to claim 1, wherein the holding member is a member having a conical shape.