JP2010190991A - Lens barrier device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce in thickness an imaging device without enlarging a lens-barrel in a radial direction while causing no fall in the strength of a barrier blade. <P>SOLUTION: The lens barrier device 1 is provided in front of an imaging lens of the imaging device 10 to protect the imaging lens by opening/closing a lens barrier. The lens barrier comprises a first lens barrier 11 covering the peripheral part of the imaging lens 31, and a second lens barrier 12 located in a position closer to the subject side than to the first lens barrier to cover the center section of the imaging lens. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a lens barrier device provided in an imaging device such as a camera.

In recent years, imaging devices such as small digital cameras have been thinned to the limit, and in order to make them thinner, it is necessary to devise a lens barrier structure that covers and protects the lens. Yes.
Patent Document 1 describes a barrier device in which a concave portion is formed on a surface facing a lens of a barrier blade. Here, the concave portion is formed by a method of scraping the surface of the barrier blade facing the lens (first embodiment) and a method of making the barrier blade itself into a spherical shape (second embodiment). This barrier device is provided with two barrier blades, and when the barrier blades are closed, the concave portions formed in the respective barrier blades are combined to form a spherical recess substantially equal to the shape of the lens center portion. It has become. The camera can be thinned by arranging the barrier device so that the center portion of the lens fits in the depression.

JP 2004-45744 A

However, in the first embodiment of the barrier device described in Patent Document 1, since the central portion of the barrier blade is thin, the strength is reduced as compared with the peripheral portion. Furthermore, since the depth of the recess cannot exceed the thickness of the barrier blade, only a slight reduction in thickness can be expected.
In both the first and second embodiments, since the entire lens is covered with two barrier blades, one barrier blade becomes large, and a lens barrel that stores the barrier blades when the camera is used. Becomes larger in the radial direction. If the lens barrel becomes larger in the radial direction, an extra space for storing the lens barrel becomes necessary.

  An object of the present invention is to reduce the thickness of an imaging device without reducing the strength of the barrier blades and without increasing the size of the lens barrel in the radial direction.

  In order to solve the above problems, the invention described in claim 1 is a lens barrier device that is provided in front of the imaging lens of the imaging device and protects the imaging lens by opening and closing the lens barrier, wherein the lens The barrier includes a first lens barrier that covers a peripheral portion of the imaging lens, and a second lens barrier that is positioned closer to the subject than the first lens barrier and covers the central portion of the imaging lens. It is characterized by.

  A second aspect of the present invention is the lens barrier device according to the first aspect, wherein the first lens barrier is divided into two.

  Invention of Claim 3 is a lens barrier apparatus of Claim 2, Comprising: One of the divided said 1st lens barriers covers the peripheral part upper side of the said imaging lens, The other is The lower side of the peripheral part of the imaging lens is covered.

  A fourth aspect of the present invention is the lens barrier device according to the first or second aspect, wherein the second lens barrier is divided into two.

  The invention according to claim 5 is the lens barrier device according to claim 4, wherein one of the divided second lens barriers covers an upper center portion of the imaging lens, and the other is The lower part of the center of the imaging lens is covered.

  A sixth aspect of the present invention is the lens barrier device according to any one of the first to fifth aspects, wherein the surface of the first lens barrier facing the second lens barrier is arranged on the surface facing the second lens barrier. An abutting portion with which the two lens barriers abut is provided.

According to the present invention, when the first and second lens barriers are closed, a recess having a depth similar to that of the first lens barrier is formed behind the second lens barrier. If the lens barrier device is arranged so that the central portion of the imaging lens is accommodated in the concave portion, the lens barrel can be shortened without removing the lens barrier, and the imaging device is made thinner by the shortened length of the lens barrel. be able to.
Further, if the first lens barrier or the second lens barrier is divided into a plurality of members, the storage space for the lens barrier when using the camera can be reduced, so that the lens barrel does not have to be enlarged in the radial direction. Therefore, the camera can be easily reduced in thickness.

It is a cross-sectional view showing an embodiment of a lens barrier device to which the present invention is applied. It is a cross-sectional view showing an embodiment of a lens barrier device to which the present invention is applied. It is a front view which shows one Embodiment of the lens barrier apparatus to which this invention is applied. It is a front view which shows one Embodiment of the lens barrier apparatus to which this invention is applied. It is a front view which shows one Embodiment of the drive mechanism of the said lens barrier apparatus. It is a front view which shows one Embodiment of the drive mechanism of the said lens barrier apparatus.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
1 and 2 show a configuration of an embodiment of the lens barrier device 1 to which the present invention is applied. The lens barrier device 1 is attached to a digital camera 10 as an imaging device. Is a shutter unit. In FIGS. 1 and 2, the camera body is not shown.

  The digital camera 10 has a lens barrel 2 that can be moved back and forth in accordance with the usage status of the digital camera 10 on the front of the camera body. That is, when the digital camera 10 is in the photographing state, the lens barrel 2 is extended forward with respect to the camera body as shown in FIG. 1, and when in the retracted state, the lens barrel 2 is attached to the camera as shown in FIG. It will be in the state accommodated in the inside of a main part.

Next, the configuration of the lens barrel 2 and the lens group 3 will be described.
The lens barrel 2 includes a fixed cylinder 21, a rotating cylinder 22, a first rectilinear cylinder 23, a second rectilinear cylinder 24, a cam cylinder 25, a first lens frame 26, a third rectilinear cylinder 27, and the like. The lens group 3 that is an imaging lens includes four lens groups in order of the first lens group 31, the second lens group 32, the third lens group 33, and the fourth lens group 34 from the subject side. Each is held inside.

  The fixed cylinder 21 is fixed inside the camera body. A helicoid 21 a is formed on the inner peripheral surface of the fixed cylinder 21. Further, a rectilinear groove 21b is formed at the upper end of the inner peripheral surface of the fixed cylinder 21 in parallel with the optical axis.

  The rotary cylinder 22 is provided inside the fixed cylinder 21 so as to be rotatable with respect to the fixed cylinder 21 and movable back and forth. Three protrusions 22 a are formed on the outer peripheral surface of the rotating cylinder 22 and are engaged with the helicoid 21 a of the fixed cylinder 21. The rear end of the outer peripheral surface of the rotating cylinder 22 is a gear 22b, which meshes with a pinion of a drive motor (not shown) provided in the camera body. A rectilinear groove 22 c is formed at the upper and lower ends of the inner peripheral surface of the rotating cylinder 22 in parallel with the optical axis. Further, a plurality of circular rotating grooves 22 d perpendicular to the rectilinear grooves 22 c are formed on the inner peripheral surface of the rotating cylinder 22.

  The first rectilinear cylinder 23 is provided inside the rotating cylinder 22 so as to be rotatable with respect to the first rectilinear cylinder 23. A protrusion 23 a is formed on the rear end upper portion of the outer peripheral surface of the first rectilinear cylinder 23 and engages with the rectilinear groove 21 b of the fixed cylinder 21. A plurality of protrusions 23 d are formed on the outer peripheral surface of the first rectilinear cylinder 23 and are engaged with the rotation groove 22 d of the rotation cylinder 22. At the upper end and the lower end of the inner peripheral surface of the first rectilinear cylinder 23, linear rectilinear grooves 23b are formed in parallel with the optical axis, respectively. A cam groove 23 c that penetrates from the outside to the inside is formed on the side peripheral surface of the first rectilinear cylinder 23.

  The second rectilinear cylinder 24 is provided inside the first rectilinear cylinder 23 so as to be movable back and forth with respect to the first rectilinear cylinder 23. Projections 24 a are formed on the upper and lower portions of the rear end of the second rectilinear cylinder 24, and engage with the rectilinear grooves 23 b of the first rectilinear cylinder 23, respectively.

  The cam cylinder 25 is provided inside the first rectilinear cylinder 23 so as to be movable back and forth with respect to the first rectilinear cylinder 23 and to be rotatable. A boss 25 a is attached to the rear end portion of the cam cylinder 25. The boss 25 a passes through the cam groove 23 c of the first rectilinear cylinder, and its tip end is engaged with the rectilinear groove 22 c of the rotating cylinder 22. A cam groove 25b is formed on the outer peripheral surface of the cam cylinder 25, and cam grooves 25c and 25d are formed on the inner peripheral surface.

  The first lens frame 26 is provided inside the second rectilinear cylinder 24 and outside the cam cylinder 25 so as to be movable back and forth with respect to the second rectilinear cylinder 24. A pin 26 a is attached to the inner peripheral surface of the first lens frame 26 and is engaged with the cam groove 25 a of the cam cylinder 25. A first lens group 31 is held in the center of the front surface of the first lens frame 26, and protrusions 26 c are formed on the front upper portion and lower front portion of the first lens frame 26, and on the left and right side portions of the first lens frame 26. Each protrusion 26d is formed. The lens barrier device 1 is attached in front of the first lens frame 26. Further, rectilinear grooves 26b are formed at the upper end and the lower end of the inner peripheral surface of the first lens frame 26 in parallel with the optical axis, respectively.

  The third rectilinear cylinder 27 is provided inside the cam cylinder 26 so as to be movable back and forth with respect to the first lens frame 26. Projections 27 a are formed on the upper and lower ends of the front end of the outer peripheral surface of the third rectilinear cylinder 27, and engage with the rectilinear grooves 26 b of the first lens frame 26, respectively. Further, rectilinear grooves 27b are respectively formed at the upper end and the lower end of the inner peripheral surface.

  The second lens frame 28 is provided inside the third rectilinear cylinder 27 so as to be movable back and forth with respect to the third rectilinear cylinder 27, and the second lens group 32 is held at the center thereof. A pin 28 a is attached to the lower end of the second lens frame 28, and the tip thereof is engaged with the cam groove 25 c of the cam cylinder 25.

  A shutter unit frame 29 is provided behind the third rectilinear cylinder 27, and the shutter unit 4 is attached to the inside thereof. A pin 29 a is attached to the lower end of the shutter unit frame 29, and the tip thereof is engaged with the cam groove 25 d of the cam cylinder 25.

  A third lens group 33 and a fourth lens group 34 are disposed behind the shutter unit 4. The third lens group 33 can be moved between the front of the fourth lens group shown in FIG. 1 and the upper side of the fourth lens group 34 shown in FIG. 2 by a driving mechanism (not shown). When the digital camera 10 is in a shooting state in which the lens barrel shown in FIG. 1 is extended, the optical axes of the third lens group and the other lens groups are matched. The fourth lens group 34 is held by an arm portion 34 a connected to a driving mechanism (not shown) provided in the camera body, and can be moved back and forth with respect to the fixed cylinder 21.

Next, the configuration of the lens barrier device 1 will be described.
3 and 4 are front views showing the lens barrier device 1, wherein 11 is a first lens barrier, 12 is a second lens barrier, and 17 is an attachment portion. The lens barrier device 1 is attached to the front portion of the lens barrel 2 and opens and closes the first lens barrier 11 and the second lens barrier 12 according to the use status of the digital camera 10, thereby It protects the front lens.

  The attachment portion 17 is a disk-shaped member having a substantially rectangular opening 17a at the center. Screw holes (not shown) are formed on the left and right ends of the attachment portion 17 so that the screws 17b can be attached. In the vicinity of the left and right screw holes, elongated arc-shaped boss holes 17c are respectively formed. As shown in FIGS. 1 and 2, the periphery of the attachment portion 17 is fixed to the front portion of the inner peripheral surface of the first lens frame 26. The front surface of the lens of the first lens group 31 is in contact with the opening 17 a, and the center of the lens protrudes slightly forward from the front surface of the mounting portion 17.

  As shown in FIG. 3, the first lens barrier 11 includes two blade-shaped members, that is, a first barrier blade 13 and a second barrier blade 14. Elongated walls 13a and 14a, which are contact portions, are formed on the side portions of the first barrier blade 13 and the second barrier blade 14, respectively. And the protrusions 13b and 14b which are contact parts are also formed in the tip part. The second lens barrier 12 is also composed of two blade-shaped members, that is, a third barrier blade 15 and a fourth barrier blade 16. Boss 15a and boss 16a are attached to the end portions of third barrier blade 15 and fourth barrier blade 16, respectively.

  The ends of the first barrier blade 13 and the third barrier blade 15 are on the left side of the mounting portion 17, and the ends of the second barrier blade 14 and the fourth barrier blade 16 are on the right side of the mounting portion 17 with screws 17b. It is mounted for rotation. Note that the third barrier blade 15 is overlapped so that the third barrier blade 15 is positioned on the front side of the first barrier blade 13, that is, the subject side, and the fourth barrier blade 16 is positioned on the front side of the second barrier blade 14. It is attached. The boss 15 a of the third barrier blade 15 and the boss 16 a of the fourth barrier blade 16 are respectively inserted into the left and right boss holes 17 c of the mounting portion 17.

  5 and 6 are front views showing a driving mechanism of the lens barrier device 1, wherein 18 is a barrier driving ring, 19a is a first spring, and 19b is a second spring. The barrier drive ring 18 is an annular member provided on the back side of the mounting portion 17 so as to be rotatable with respect to the mounting portion 17. The left and right side portions of the barrier drive ring 18 are slightly wider, and openings 18a are formed in the widened portions. A boss 15a and a boss 16a are inserted through the left and right openings 18a, respectively. In addition, protrusions 18b are formed on the upper and lower portions of the barrier drive ring 18, respectively. When the barrier drive ring 18 is attached in front of the first lens frame 26, as shown in FIG. 5, the protrusion 26c is behind the upper and lower portions of the opening 17a, and the protrusion 26d is behind the left and right side portions of the opening 17a. Located in each.

  A first spring 19a is hung between the upper and lower protrusions 18b and the upper and lower protrusions 26c of the first lens frame 26, and the barrier drive ring 18 is urged to rotate in a clockwise direction when viewed from the front. ing. A second spring 19b is hung between the tip of the boss 15a and the boss 16a penetrating the opening 18a and the left and right protrusions 26d of the first lens frame 26, respectively. The barrier blade 16 is biased in the closing direction. The biasing force of the first spring 19a is stronger than the biasing force of the second spring 19b.

Next, operations of the lens barrel 2 and the lens barrier device 1 will be described.
First, in the housed state shown in FIG. 2, the lens barrel 2 is contracted and housed inside the camera body, and the third lens group 33 is retracted above the fourth lens group 34. As described above, since the urging force of the first spring 19a is stronger than the urging force of the second spring 19b, the first lens barrier 11 and the second lens barrier 12 are opened when no force is applied from the outside. However, a ring rotation mechanism (not shown) stops the barrier drive ring 18 at the position shown in FIG. Therefore, in the retracted state, the first lens barrier 11 and the second lens barrier 12 are closed.

  When a drive motor (not shown) is operated, the pinion of the drive motor rotates and the rotating cylinder 22 rotates. Since the protrusion 22a formed on the outer peripheral surface of the rotating cylinder 22 and the helicoid formed on the fixed cylinder 21 are engaged, the rotating cylinder 22 advances in parallel with the optical axis while rotating and is drawn out of the camera body. It is. Further, since the protrusion 23d of the rectilinear cylinder 23 is engaged with the rotation groove 22d of the rotating cylinder 22, and the protrusion 23a of the rectilinear cylinder 23 and the rectilinear groove 21a of the fixed shaft are engaged, the rotation of the rectilinear cylinder 23 is restricted. It moves forward together with the rotating cylinder 22.

  Further, since the boss 25a of the cam cylinder 25 is engaged with the rotating cylinder 22, the cam cylinder 25 rotates in accordance with the rotation of the rotating cylinder 22 and advances in the optical axis direction. The second rectilinear cylinder 24 also moves forward in accordance with the movement of the cam cylinder 25. The pin 26a is engaged with the cam groove 25b on the outer peripheral surface of the cam cylinder 25, the pin 28a is engaged with the cam groove 25c on the inner peripheral surface, and the pin 29a is engaged with the cam groove 25d. Therefore, when the cam cylinder 25 rotates / advances, the first lens frame advances in accordance with the movement of the cam cylinder 25, and the second lens frame and the third rectilinear cylinder move to predetermined positions. Finally, the third lens group moves to the front of the fourth lens group, and the state shown in FIG. 1 is reached, and the extension operation of the lens barrel 2 from the camera body is completed.

  Next, a ring rotation mechanism (not shown) releases the stationary state of the barrier drive ring 18. As described above, the barrier drive ring 18 is urged by the first spring 19a to rotate clockwise in front view. Moreover, the 3rd barrier blade | wing 15 and the 4th barrier blade | wing 16 are urged | biased by the 2nd spring 19b in the closing direction. For this reason, the boss 15a of the third barrier blade 15 and the boss 16a of the fourth barrier blade 16 push the barrier drive ring 18 counterclockwise when viewed from the front, so that the barrier drive ring 18 simultaneously rotates in opposite directions. Although the biasing force of the first spring is stronger than the biasing force of the second spring, the barrier drive ring 18 starts rotating clockwise. Then, the boss 15a and the boss 16a are respectively pressed against the wall surface of the opening 18a, and the third barrier blade 15 and the fourth barrier blade 16 start rotating counterclockwise around the screw 17b, that is, in a direction away from each other. In this way, the second lens barrier 12 is opened.

  When the third barrier blade 15 and the fourth barrier blade 16 are rotated to the place where the third barrier blade 15 and the fourth barrier blade 16 are located, the outer portion of the third barrier blade 15 is on the wall 13a of the first barrier blade 13 and the outer portion of the fourth barrier blade 16 is on the second barrier. Each abuts against the wall 14 a of the blade 14. As the third barrier blade 15 and the fourth barrier blade 16 continue to rotate, the first barrier blade 13 is pushed by the third barrier blade 15 and the second barrier blade 14 is pushed by the fourth barrier blade 16 and away from each other. As a result, the first lens barrier is also opened as shown in FIGS. As shown in FIG. 4, when the opening 17a of the mounting portion 17 is completely exposed, the movement of the boss 15a and the boss 16a is restricted by the boss hole 17c, and the movement of each barrier blade stops.

  In order to change from the shooting state to the storage state, first, a ring rotation mechanism (not shown) rotates the barrier drive ring 18 counterclockwise when viewed from the front. When the barrier drive ring 18 begins to rotate, the bosses 15a and 16a are pulled by the second spring 19b, and the third barrier blade 15 and the fourth barrier blade 16 rotate clockwise with the screw 17b as the rotation axis in accordance with the movement of the opening 18a. That is, the rotation starts in the direction approaching each other, and the second lens barrier is closed.

  When the third barrier blade 15 and the fourth barrier blade 16 are rotated to the place where the third barrier blade 15 and the fourth barrier blade 16 exist, the front end portion of the third barrier blade 15 extends to the protrusion 13b of the first barrier blade 13 and the front end portion of the fourth barrier blade 16 extends to the second barrier blade. The blade 14 abuts against the protrusion 14b of the blade 14, respectively. When the third barrier blade 15 and the fourth barrier blade 16 continue to rotate, the first barrier blade 13 is pushed by the third barrier blade 15, and the second barrier blade 14 is pushed by the fourth barrier blade 16 and approaches each other. As a result, the first lens barrier is also closed as shown in FIGS. When the third barrier blade 15 and the fourth barrier blade 16 come into contact with each other, the ring rotation mechanism stops the rotation of the barrier drive ring 18 and stops the barrier drive ring 18 in that state. Thus, since the first lens barrier 11 is opened and closed by the power of the second lens barrier 12, the mechanism for opening and closing the lens barrier can be simplified.

  When the first lens barrier and the second lens barrier are closed, the third lens group retreats above the fourth lens group, and the lens barrel 2 contracts in the reverse procedure of the above-described extension operation, so that the inside of the camera body To return to the state shown in FIG. When the first lens barrier 11 and the second lens barrier 12 are closed, the first lens barrier 11 covers the upper and lower peripheral portions of the foremost lens of the first lens group 31, and the second lens barrier 12. However, it covers the center of the foremost lens of the first lens group 31 on the subject side of the first lens barrier 11.

  Then, in the space surrounded by the side surface of the first lens barrier 11 (the lower side surface of the barrier blade 13 and the upper side surface of the barrier blade 14) and the back surface of the second lens barrier 12, which are divided into the upper and lower sides, the first lens group 31 is just right. The center of the foremost lens can be accommodated. Accordingly, the arrangement of the lens barrier device 1 can be moved rearward as compared with the prior art, so that the lens barrel 2 can be shortened. As a result, the thickness of the digital camera 10 can be reduced.

In the above embodiment, a digital camera is used. However, the present invention is not limited to this and may be a film camera or a video camera.
Further, the number of wings constituting the first and second lens barriers can be changed (for example, the first lens barrier is composed of two sheets and the second lens barrier is composed of one barrier wing), the second It is arbitrary to use spherically formed blades as the lens barrier, and it is needless to say that other specific detailed structures can be appropriately changed.

10 Digital camera (imaging device)
DESCRIPTION OF SYMBOLS 1 Lens barrier apparatus 11 1st lens barrier 12 2nd lens barrier 13 1st barrier blade | wing 13a Wall (contact part)
13b Protrusion (contact part)
14 Second barrier blade 14a Wall (contact portion)
14b Protrusion (contact part)
15 3rd barrier blade 15a boss
16 Fourth barrier blade 16a Boss 17 Mounting portion 17a Opening 17b Screw 17c Boss hole 18 Barrier drive ring 18a Opening 18b Projection 19a First spring 19b Second spring 2 Lens barrel 26c Projection 26d Projection 3 Lens group 4 Shutter unit

Claims (6)

A lens barrier device that is provided in front of an imaging lens of an imaging device and protects the imaging lens by opening and closing a lens barrier,
The lens barrier includes: a first lens barrier that covers a peripheral portion of the imaging lens; and a second lens barrier that is positioned closer to the subject than the first lens barrier and covers a central portion of the imaging lens. A lens barrier device.   The lens barrier device according to claim 1, wherein the first lens barrier is divided into two sheets.   3. The lens barrier according to claim 2, wherein one of the divided first lens barriers covers an upper peripheral portion of the imaging lens, and the other covers a lower peripheral portion of the imaging lens. apparatus.   The lens barrier device according to claim 1, wherein the second lens barrier is divided into two.   5. The lens barrier according to claim 4, wherein one of the divided second lens barriers covers an upper center portion of the imaging lens, and the other covers a lower center portion of the imaging lens. apparatus.   6. The contact portion with which the second lens barrier contacts is provided on a surface of the first lens barrier that faces the second lens barrier. 6. The lens barrier device according to Item.

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