JP2009008717A - Light adjusting device and optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact light adjusting device where a wiring for diaphragm control need not be pulled out from a diaphragm mechanism, and an optical device. <P>SOLUTION: The light adjusting device 100 having an optical aperture 111 which is fixed and a diaphragm blade 105 which can be displaced has a first magnet 110 fixed on the diaphragm blade 105 and a second magnet displacing device 102 changing external magnetic field acting on the first magnet 110. By displacing the first magnet 110 by the change of external magnetic field, the diaphragm blade 105 is displaced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light adjusting device and an optical device.

  An optical system with a simple configuration that does not have an aperture adjustment function has been applied to an ultra-small imaging mechanism used in a mobile phone or an endoscope. In recent years, with the increase in the number of pixels in a small image sensor, there is an increasing demand for an ultra-small aperture adjusting mechanism for improving image quality. As an example of an optical aperture device applicable to such an ultra-small image pickup mechanism, an aperture adjustment mechanism disclosed in Patent Document 1 will be described with reference to FIG.

  The diaphragm blades 1 and 2 are pivotally attached to the main plate 20. One end of each of the diaphragm blades 1 and 2 is engaged with one end of the first shape memory alloy 3 and is stretched over the connecting plate 7. The pair of diaphragm blades 1 and 2 is urged in the closing direction by the springs 4a and 4b. One end of the second shape memory alloy 5 is attached to the connecting plate 7 and one end of the spring 6 is locked, and the connecting plate 7 is urged downward. The SMA drive circuit 12 causes the first shape memory alloy 3 to self-heat and operates the diaphragm blades 1 and 2. When there is a large environmental change, the device is protected by the second shape memory alloy 5 and stable control can be performed without depending on the temperature change.

JP-A-2005-128450

  In a high-resolution compact imaging device, a light adjusting device such as a diaphragm adjusting mechanism is generally disposed between a plurality of lenses. In the conventional diaphragm adjusting mechanism, it is necessary to draw out wiring for energizing the shape memory alloy from the diaphragm mechanism. Here, the distance between the lenses is usually very small, and it is quite difficult to draw out the wiring therefrom. In addition, the necessity of wiring has been an obstacle to miniaturization. Further, when it is desirable to store the imaging optical system in a sealed container such as an endoscope, it is considerably difficult to draw out the wiring from the sealed container.

  The present invention has been made in view of the above, and it is an object of the present invention to provide a small light adjustment device that does not require drawing of a diaphragm control wiring from an aperture mechanism and an optical device using the light adjustment device. To do.

  In order to solve the above-mentioned problems and achieve the object, the present invention provides a light adjusting device having a fixed optical aperture and a displaceable incident light adjusting means, and a first fixed to the incident light adjusting means. And a means for changing the external magnetic field acting on the first magnet, and the incident light adjusting means is operated by displacing the first magnet by the change of the external magnetic field. Equipment can be provided.

  Further, according to a preferred aspect of the present invention, it is desirable that the change of the external magnetic field acting on the first magnet is made by the displacement of the second magnet arranged separately from the first magnet.

  According to a preferred aspect of the present invention, it is desirable that the displacement of the second magnet is a displacement in the optical axis direction.

  According to a preferred aspect of the present invention, it is desirable that the incident light adjusting means is a stop ring having an aperture smaller than the optical aperture.

  Further, according to a preferred aspect of the present invention, it is desirable that the incident light adjusting means is an optical filter that limits a transmitted light amount or a wavelength range.

  According to another aspect of the present invention, a container in which an optical aperture, a displaceable incident light adjusting means, a first magnet fixed to the incident light adjusting means, and an optical element are disposed, and the outside of the container And an external magnetic field changing means disposed in the optical device, wherein the external magnetic field changing means changes the external magnetic field acting on the first magnet.

  According to a preferred aspect of the present invention, it is desirable that the external magnetic field changing means is constituted by a displaceable third magnet.

  According to a preferred aspect of the present invention, it is desirable that the displacement of the third magnet is a displacement in the optical axis direction.

  According to the present invention, it is possible to provide a small light adjustment device that does not require drawing out a diaphragm control wiring from the diaphragm mechanism, and an optical device using the light adjustment device.

  Embodiments of a light adjusting device and an optical device according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of the light adjusting device 100 of this embodiment. The light adjusting device 100 according to the present embodiment includes an aperture mechanism 101 and a second magnet displacement device 102.

  FIG. 2 shows an exploded view of the aperture mechanism 101. The aperture mechanism 101 includes a lower substrate 103, an upper substrate 104, aperture blades 105, a spacer 106, a closing stopper 107, and an opening stopper 108, which are stacked as shown. Here, the thicknesses of the lower substrate 103, the upper substrate 104, and the aperture blade 105 are each 0.05 mm, and the spacers 106, the stopper 107 when closed, and the stopper 108 when opened are each 0.1 mm. Further, the lower substrate 103 and the upper substrate 104 are bonded via a spacer 106, a closing stopper 107, and an opening stopper 108. The diaphragm mechanism 101 corresponds to incident light adjusting means.

  A rotary shaft 109 and a cylindrical first magnet 110 are press-fitted into the diaphragm blade 105. The rotating shaft 109 has a diameter of 0.15 mm and a height of 0.2 mm, and the first magnet 110 has a diameter of 0.2 mm and a height of 0.4 mm. The lower substrate 103 is formed with an optical aperture 111, a rotary shaft insertion hole 112, and a first magnet guide notch 113. Similarly, an optical opening 114, a rotation shaft insertion hole 115, and a first magnet guide notch 116 are formed in the upper substrate 104 as well. The diameter of the optical aperture 114 is set to be the same as or slightly larger than the optical aperture 111.

  Here, the rotation shaft 109 is inserted into the rotation shaft insertion hole 112 and the rotation shaft insertion hole 115, so that the diaphragm blade 105 can be rotationally displaced about the rotation shaft 109. The range is limited by the closing stopper 107 and the opening stopper 108. In addition, the first magnet 110 is provided with a first magnet guide notch 113 and a first magnet guide notch 116 in a rotationally displaceable range, and is configured not to contact the lower substrate 103 and the upper substrate 104.

  The diaphragm blade 105 is formed with a diaphragm ring 118 having a diaphragm opening 117 at the center thereof. The aperture opening 117 is smaller than the optical aperture 111, and the outer diameter of the aperture ring 118 is set slightly larger than the optical aperture 111. Here, the relationship between the optical aperture 111 and the aperture ring 118 will be described. The diaphragm blade 105 is rotationally displaced about the rotation shaft 109. For example, when the aperture ring 118 contacts the closing stopper 107, the center of the aperture opening 117 and the center of the optical aperture 111 coincide. Further, when the aperture ring 118 comes into contact with the opening stopper 108, the aperture ring 118 is completely retracted from the optical aperture 111.

  Next, the 2nd magnet displacement apparatus 102 is demonstrated using FIG. One end of the shape memory alloy wire 120 is fixed to the second magnet 119. A bias spring 121 and an insulating tube 122 are passed through the shape memory alloy wire 120. The other end of the shape memory alloy wire 120 is fixed to the crimping member 123. Further, the caulking member 123 is also fixed at the end of the tube 122 opposite to the second magnet 119. The second magnet displacement device 102 corresponds to an external magnetic field changing unit.

  Although not particularly shown, wiring for energization heating is formed at both ends of the shape memory alloy wire 120. Here, when the shape memory alloy wire 120 is energized and heated, it contracts due to phase transformation, and the second magnet 119 is displaced toward the tube 122 against the bias spring 121. Further, when energization to the shape memory alloy wire 120 is subsequently released, the shape memory alloy wire 120 is expanded by the force of the bias spring 121, and the second magnet 119 is displaced in the direction opposite to the tube 122.

  As described above, the second magnet displacing device 102 can displace the second magnet 119 according to the change in the energization state of the shape memory alloy wire 120. The direction of displacement of the second magnet 119 is the optical axis direction of incident light in the aperture mechanism 101 as can be seen from the arrangement of FIG.

  Next, the operation of the light adjusting apparatus 100 of the present embodiment will be described with reference to FIGS. 4A and 4B and FIGS. 5A and 5B. 4A and 4B show the operation when the shape memory alloy wire 120 is in a non-energized state, and FIGS. 5A and 5B show the operation when the shape memory alloy wire 120 is in an energized state. Is shown. 4 (a) and 5 (a) are top views, and FIG. 4 (b) and FIG. 5 (b) are side views. Here, with respect to the top view, the upper substrate 104 and the second magnet drive mechanism 102 are not shown for easy understanding.

  Further, the position of the end portion 124 of the tube 122 on the second magnet 119 side is assumed to be fixed relatively to the lower substrate 103. Further, both the first magnet 110 and the second magnet 119 are magnetized in the optical axis direction. As shown, the first magnet 110 has the S pole on the upper side, while the second magnet 119 has the S pole on the lower side.

  First, an operation in which the shape memory alloy wire 120 is in a non-energized state will be described with reference to FIGS. In this state, the centers of the first magnet 110 and the second magnet 119 are at the same position in the optical axis direction of the aperture mechanism 101. In this state, the S pole of the first magnet 110 and the N pole of the second magnet 119 face each other, and the N pole of the first magnet 110 and the S pole of the second magnet 119 face each other.

  For this reason, the first magnet 110 is attracted to the second magnet 119 and is displaced to the outer peripheral direction side of the aperture mechanism 101. Therefore, the aperture blade 105 rotates about the rotation shaft 109 in the clockwise direction in the top view until the aperture ring 118 contacts the stopper 108 when opened. As a result, the aperture ring 118 is retracted with respect to the optical aperture 111, and the aperture mechanism 101 is opened.

  Next, the operation when the shape memory alloy wire 120 is energized will be described with reference to FIGS. The shape memory alloy wire 120 contracts by energization. The second magnet 119 is displaced about ½ of the length of the second magnet 119 in the optical axis direction. At this time, the N pole of the first magnet 110 and the N pole of the second magnet 119 face each other.

  For this reason, a repulsive force is generated between the first magnet 110 and the second magnet 119, and the first magnet 110 is displaced toward the center of the aperture mechanism 101. As a result, the aperture blade 105 rotates about the rotation shaft 109 counterclockwise in the top view until the aperture ring 118 comes into contact with the stopper 107 when closed. As a result, the aperture ring 118 covers the optical aperture 111, and the aperture mechanism 101 is in the apertured state in which the aperture diameter is defined by the aperture aperture 117.

  As described above, in the light adjusting device 100 of the present embodiment, the diaphragm can be opened and closed by displacing the second magnet 119 in the optical axis direction depending on the energization state of the shape memory alloy wire 120, that is, the presence or absence of the energization. it can.

  Next, an embodiment in which the light adjusting device of the present invention is applied to an actual imaging optical system will be described. FIG. 6 is a diagram illustrating a schematic configuration of an optical device 200 according to the second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  In the optical device 200 according to the second embodiment, a plurality of lenses 126, an image sensor 127, and a diaphragm mechanism 101 are arranged in a cylindrical case 125. An image of an object (not shown) is formed on an image pickup surface of an image pickup device 127, for example, a CCD, by a plurality of lenses 126. The second magnet displacement device 102 is disposed outside the case 125. The second magnet displacement device 102 is fixed to the case 125 at the end portion 124 of the tube 122 on the second magnet 119 side. The lower substrate 103 of the diaphragm mechanism 101 is fixed to the case 125. Here, the case 125 corresponds to a container. The lens 126 and the image sensor 127 correspond to optical elements. The second magnet 119 corresponds to the third magnet.

  When the shape memory alloy wire 120 is not energized, the second magnet 119 is positioned directly beside the first magnet 110 of the aperture mechanism 101. As described with reference to FIGS. 4A and 4B and FIGS. 5A and 5B, the first magnet 110 is displaced by the energized state of the shape memory alloy wire 120 to open and close the aperture. . As described above, in the optical apparatus according to the present embodiment, since no electrical wiring is required for the aperture opening / closing control of the aperture mechanism 101, wiring for opening / closing the aperture is provided from within the case 125 containing the optical system. It is possible to open and close the aperture without drawing it out.

  Further, in this embodiment, the displacement direction of the second magnet 119 is the optical axis direction, and the second magnet displacement device 102 extends in the optical axis direction, and the occupied area on the plane perpendicular to the optical axis is small. Therefore, it is particularly suitable for applications in which a reduction in diameter is strongly desired, such as an optical device, particularly an endoscope.

Further, by replacing the aperture ring portion in this embodiment with an optical filter, it can be used as an optical filter detaching device that changes the transmitted light amount or the transmitted wavelength region.
As for the magnetization directions of the first magnet 110 and the second magnet 119, in addition to the combinations shown in the present embodiment, several magnetization directions for displacing the diaphragm blade 105 in accordance with the displacement of the second magnet. Combinations of these are possible.

  As described above, the light adjusting device and the optical device according to the present invention do not need to draw out control wiring from the diaphragm mechanism. For this reason, it becomes easy to incorporate a diaphragm adjusting mechanism in a small-sized imaging device having a small lens interval. Further, the light adjusting device and the optical device can be reduced in size. Furthermore, since there is no need to draw out the wiring, the effect of being applicable to a device that seals the light adjusting device is achieved.

  As described above, the light adjusting device and the optical device according to the present invention are useful for a small-sized image sensor, and are particularly suitable for a device that seals an imaging system or a device that requires a reduction in diameter.

It is a perspective view of the light adjustment apparatus of Example 1 of this invention. It is an exploded view of an aperture mechanism. It is a figure which shows the structure of a 2nd magnet displacement apparatus. (A), (b) is a figure explaining the operation | movement at the time of the deenergization of a shape memory alloy wire, respectively. (A), (b) is a figure explaining the operation | movement at the time of electricity supply of a shape memory alloy wire, respectively. It is a figure which shows the structure of the optical apparatus of Example 2 of this invention. It is a figure which shows the structure of the conventional aperture adjustment mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Diaphragm mechanism 102 2nd magnet displacement apparatus 103 Lower board 104 Upper board 105 Diaphragm blade 106 Spacer 107 Closed stopper 108 Opened stopper 109 Rotating shaft 110 1st magnet 111, 114 Optical opening 112, 115 Rotating shaft insertion hole 113, 116 First magnet guide notch 117 Diaphragm opening 118 Diaphragm ring 119 Second magnet 120 Shape memory alloy wire 121 Bias spring 122 Tube 123 Caulking member 124 Side end 125 Case 126 Lens 127 Imaging element 1, 2 Diaphragm blade 3, 5 Shape memory Alloy 4a, 4b, 6 Spring 7 Connecting plate 12, 15 SMA drive circuit 13a, 13b, 16a, 16b Wiring 20 Ground plate

Claims (8)

In a light adjusting device having a fixed optical aperture and a displaceable incident light adjusting means,
A first magnet fixed to the incident light adjusting means;
Means for changing an external magnetic field acting on the first magnet,
The light adjusting device, wherein the incident light adjusting means is operated by displacing the first magnet by a change in the external magnetic field.   2. The light adjusting device according to claim 1, wherein a change in an external magnetic field acting on the first magnet is made by a displacement of a second magnet arranged separately from the first magnet.   The light adjusting device according to claim 2, wherein the displacement of the second magnet is a displacement in an optical axis direction.   2. The light adjusting device according to claim 1, wherein the incident light adjusting means is a stop ring having an opening smaller than the optical opening.   The light adjusting device according to claim 1, wherein the incident light adjusting unit is an optical filter that limits a transmitted light amount or a wavelength range. A container in which a fixed optical aperture, a displaceable incident light adjusting means, a first magnet fixed to the incident light adjusting means, and an optical element are disposed;
An external magnetic field changing means disposed outside the container,
The optical apparatus, wherein the external magnetic field changing means changes an external magnetic field acting on the first magnet.   The optical apparatus according to claim 6, wherein the external magnetic field changing means is constituted by a displaceable third magnet. 8. The optical apparatus according to claim 7, wherein the displacement of the third magnet is a displacement in the optical axis direction.

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