JP2008299224A - Vibration method for evaluating camera shake correcting function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration method for selectively applying vertical and lateral vibration to a lens to be tested without remounting the lens (including a body) removed from a test table. <P>SOLUTION: The test table 3 on which the lens 1 is mounted in a direction orthogonal to an optical axis L of the lens 1 to be tested is disposed, and on the back face side of the test table 3, a vibration body 5 applying vibration to the back face in a direction to cross the optical axis L is angularly rotated around the optical axis L of the lens 1 to be tested, and positioned to select and apply lateral and vertical vibration to the lens 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is an evaluation test performed to evaluate the correction function of a camera lens or a camera body (with a lens, the same applies hereinafter) in which a camera shake correction function is incorporated as a single lens reflex camera. The present invention relates to a vibration method for applying vibration (artificial camera shake phenomenon) to the lens and the body.

  In an evaluation test of an interchangeable lens or camera body equipped with a camera shake correction function, the lens under test or the body under test with the lens attached (hereinafter sometimes referred to simply as “the lens under test”) is a slight amount corresponding to camera shake. The form of applying vibration is not shown in the figure, but the test stand in a horizontal posture with a single lens (or a camera body with the lens attached) is fixed to be eccentric to be able to rotate to the other end while using one end of the lower surface of the test stand as a fulcrum. It is conceivable that the cam is brought into contact with and supported from the lower surface of the table, and the eccentric cam is rotated to give the test table oscillation vibration centered on a fulcrum.

In the above, the fulcrum of the test bench is set at a position corresponding to the focal point (imaging point) of the lens under test. Therefore, when the test beam (also referred to as spot light) is projected onto the lens under test from the front, A test beam forms an image on the screen.
Therefore, if a position sensor such as a PSD is placed at the image formation point and the test is performed, if the image stabilization mechanism built into the lens or body functions normally, the image formation of the test beam connected to the image formation point of this lens will fluctuate. If it is detected based on the output signal of the sensor such as the PSD that the imaging function fluctuates if the correction function does not function normally, the camera shake correction function can be evaluated.

  However, in the above-described vibration mode, only vibration in the vertical direction (pitching) of the lens and body can occur on the test bench. Therefore, in order to give the lens vibration (yawing) in the left-right direction, There was a problem that the body had to be unmounted, and the lens and body had to be rotated 90 degrees on the optical axis and remounted on the test bench.

  Therefore, in the present invention, it is possible to selectively apply vibrations in the vertical direction and the horizontal direction to the lens without removing the lens under test (including the body) mounted on the test stand and remounting. It is an object to provide a vibration method.

  The configuration of the vibration method of the present invention made for the purpose of solving the above-described problem is that a test table on which the lens is mounted is arranged in a direction orthogonal to the optical axis of the lens under test, and the back side of the test table In addition, by positioning a vibrating body that imparts vibration in the direction across the optical axis on the back surface thereof by rotating the angular rotation around the optical axis of the lens under test, It is characterized by selecting and adding vibrations.

  The vibration method of the present invention includes a test stand on which the lens is mounted in a direction orthogonal to the optical axis of the lens under test (including both the lens alone or the one mounted on the camera body, the same applies hereinafter). And placing a vibration body for applying vibration in the direction crossing the optical axis to the test table on the back surface of the test table by rotating the exciter around the optical axis of the lens under test. Since vibration in the left-right direction (yawing) and up-down direction (pitching) can be selected and applied to the lens, the left-right direction ( Yawing) and vertical (pinching) vibrations can be applied.

Next, an embodiment of the method of the present invention will be described with reference to the drawings.
FIG. 1 is a side view schematically showing an example of an evaluation apparatus for a camera shake correction function using the vibration method of the present invention.

  In FIG. 1, 1 is a lens for a single-lens reflex camera, the lens to be inspected by the present invention, and 2 is a light source for a test pattern placed on the optical axis L of the lens 1, for example, laser light or LED Although collimated light such as light is used, the light source is not limited to these in the present invention.

  Reference numeral 3 denotes a test stand for supporting the lens 1 on its light receiving side (back side) and holding the lens 1 for a test. Here, a direction perpendicular to the optical axis L of the lens 1 (vertical direction in the figure) Is arranged in. A chuck 3a for setting the lens 1 through the center is provided at the center of the test table 3, and the rear surface side of the test table 3 is a focal point (imaging surface) f of the lens 1. A position sensor 4 such as a PSD is disposed on the pixel surface of the lens 1. Since this sensor 4 receives the test beam (spot light) from the light source 2, the lens 1 is placed at the center of the test table 3 so that the spot light passing through the lens 1 reaches the pixel surface of the PSD. A through hole with a chuck 3a for loose insertion is provided.

  Reference numeral 5 denotes a vibration bar for imparting vibration to the test table 3 that is shaken by hand. Here, the vibration bar is formed by a substantially L-shaped rigid member in contact with the back surface of the test table 3, and the horizontal portion below is ± It is connected to a shaft 6a of a vibration motor 6 that performs reciprocal vibration within a range of about 0.1 to 0.5 degrees. The vibration bar 5 and the motor 6 form an example of a vibration body. The center of the shaft 6a of the vibration motor is set to coincide with the focal point (imaging plane) of the lens 1.

  The vibration motor 6 is placed on the distal end side (left side in FIG. 1) of the support arm 7 in a horizontal posture. As a result, when the motor 6 vibrates in a range of about 1 to 8 Hz with a reciprocating rotation angle in a range of about ± 0.1 to 0.5 degrees as an example, a vertical portion of the excitation bar 5 is formed at the lower end of the test table 3. The vibration in the direction crossing the optical axis L (the direction perpendicular to the drawing sheet) is added by the left and right vibrations. As a result, the lens 1 is given a vibration (yawing) in the left-right direction with respect to the optical axis L in FIG.

  On the other hand, the rear end portion of the horizontal support arm 7 is coupled to the lower end portion of the base member 8 in a vertical posture in FIG. 1, and is formed as a substantially L-shaped revolving arm as a whole. A shaft mounting bracket 8a is disposed on the upper end side of the base member 8, and a horizontal shaft 9 is fixed to the bracket 8a as a revolving shaft. As for both ends of the shaft 9, the left end (one end) side in FIG. 1 is supported by the bearing 10, and the motor 11 is connected to the other end side. In FIG. 1, F is a fixed system such as a base or a substrate.

  Due to the crank-shaped form formed by the revolving arm and the shaft 9 formed by the support arm 7 and the base member 8, the vibration motor 6 provided on the support arm 7 is integrated with the vibration bar 5 by rotating the motor 11 by, for example, 90 degrees. It can be rotated (in a plane orthogonal to the paper surface of FIG. 1). Therefore, when the rotation is set to 90 degrees as an example, the contact coupling position (engagement position) between the vibration bar 5 and the test table 3 is moved around the optical axis L from the position shown by the solid line in FIG. It will be displaced to a position rotated 90 degrees in the direction of rotation or in the opposite direction. The vibration bar 5 and the test table 3 are coupled by a locking tool such as a temporary fixing clamp 3b during the test, and the coupling is released during the 90-degree rotation. As a result, even if the vibration bar 5 is rotated 90 degrees, the orientation of the lens and the test stand 3 remains as shown in FIG.

  The vibration bar 5 rotates 90 degrees, and the direction of the contact coupling with the test table 3 is changed from the vertical direction in FIG. 1 to the horizontal direction (in the test table 3, the left and right direction when the optical axis L is viewed from the front). Then, the lens under test 1 mounted and fixed on the test table 3 in the original orientation is subjected to the vertical direction of the lens 1 through the test table 3 (light) due to vibration by the motor 6 of the vibration bar 5. Vibration (pitching) at the front of the axis L) is applied.

  In the method of the present invention, pitching (vibration in the vertical direction) and yawing (vibration in the horizontal direction) with respect to the lens 1 are, for example, 90 in the forward and reverse directions of the motor 11 without changing the mount of the lens 1 with respect to the test table 3. It can be arbitrarily changed or set by the angular rotation of degrees. Accordingly, when the vibration bar 5 is rotated 45 degrees around the optical axis L by the rotation of the motor 11 and the vibration bar 5 is vibrated by driving the motor 6 in this direction, the lens 1 is pitched (up and down movement). Since vibration having both components of yawing (horizontal motion) is applied, the camera shake correction function in the pitching direction and the yawing direction of the lens 1 can be evaluated in one test.

  Here, the handling of the signal for evaluating the action of the camera shake correction mechanism built in the lens 1 generated in the position sensor 4 is equivalent to the sensor output when there is no vibration when the correction mechanism operates normally as an example ( It can be handled as if it is normal (no problem), and if there is a problem with the operation of the correction mechanism, it is judged abnormal because the difference from the sensor output when not vibrating is significant. That's fine. In the test with the lens 1 mounted on the body, a signal generated on the image receiving surface of the image sensor by a CCD or the like disposed in the body instead of the position sensor 4 is used as a signal for evaluation. be able to.

  In general, the performance of the camera shake correction mechanism incorporated in the interchangeable lens 1 is not uniform due to the grade, structure, price, etc. of each lens or camera. That is, there is a high-performance correction mechanism and a normal level performance correction function.

  In the present invention, the vibration amplitude and the frequency applied to the test table 3 can be freely and continuously changed according to the performance of the camera shake correction function incorporated in the lens under test 1. This makes it possible to make a reasonable evaluation according to the performance of the camera shake correction function incorporated in the lens or the body.

  In the above example, the light receiving surface of the position sensor 4 is fixed at a position that coincides with the focal point f of the lens 1, but the position of the sensor 4 is disposed in front of the focal point f in FIG. 1 (in this case, the lens 1 is also disposed in front. May be tested). Further, by slightly modifying the apparatus shown in FIG. 1 capable of carrying out the method of the present invention, whether or not the rolling correction function is functioning for the lens 1 or the body in which the rolling correction mechanism is built in the lens 1 or the body. It can be formed in a device for

  The present invention is as described above, and a test table on which the lens is mounted is disposed in a direction orthogonal to the optical axis of the lens under test, and the optical axis is crossed on the back side of the test table. The vibration body for applying the vibration in the direction is positioned by rotating it around the optical axis of the lens to be tested, so that the vibration in the horizontal direction and the vertical direction is selectively applied to the lens. Therefore, it is possible to obtain a special effect that vibrations in the vertical direction and the horizontal direction can be selectively applied to the lens without removing the lens to be tested mounted on the test bench and remounting.

The side view which showed typically an example of the evaluation apparatus of the camera-shake correction function using this invention excitation method.

Explanation of symbols

1 Lens to be tested (including lenses attached to the body)
2 Light source (or pattern) for testing
3 Test stand 4 Sensor 5 Excitation bar 6 Excitation motor 7 Support arm 8 Base member 9 Revolving shaft
10 Bearing
11 Motor

Claims (3)

  A test table on which the lens is mounted is oriented in a direction perpendicular to the optical axis of the lens under test, and vibration is applied to the test table in a direction crossing the optical axis on the back side of the test table. A vibration method for evaluating a camera shake correction function of a camera, wherein a vibration body is provided, and vibrations corresponding to camera shake are applied to the test table by vibrating the vibration body.   2. The vibration can be selectively applied to the lens in the left-right direction (yawing) and the up-down direction (pitching) by positioning the vibrating body with respect to the optical axis of the lens. Method for evaluating the camera shake correction function of cameras.   The camera shake correction function of the camera according to claim 1, wherein the vibration exciter is disposed at an angle of approximately 45 degrees around the optical axis with respect to the back surface of the test bench and can apply vibration having a yawing component and a pitching component. Exciting method to do.

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