JPH0555666U - Flange back adjustment mechanism - Google Patents

Abstract

(57) [Summary] [Purpose] To enable large switching of flange back and fine adjustment. A rocking cam 44 for moving the imaging element 42 back and forth is provided in the camera housing 43, and an adjusting screw 45 for adjusting the rocking position of the rocking cam 44 by being operated from the outside of the camera housing 43 is provided. Adjust the adjusting screw 45 after ensuring the swinging distance of the swinging cam 44 to be equal to or more than the difference D of the flange back which differs depending on the type of the lens barrel mounted on the camera housing 43 such as the C mount method or the CS mount method. By swinging the swing cam 44 largely, the flange back is largely changed according to the lens mount method, and on the other hand, the swing screw 44 is slightly swung by slightly moving the adjusting screw 45, so that the flange back is slightly changed. Make fine adjustments to the back.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a flange back adjustment mechanism that enables a large amount of flange back switching and fine adjustment.

[0002]

[Prior Art]

 Lenses used in imaging devices such as television cameras have a distance (flange focal length) from the mounting reference plane (flange surface of the lens barrel) to the focal plane (optical image forming surface) to the camera housing. , JIS standards. The flange focal length is generally called a flange back, and is usually adjustable by moving either the lens mount or the image pickup device. However, this flange back needs to be adjusted strictly in order to obtain a good quality reproduced image, and various proposals have been made in the past as a flange back adjustment mechanism for adjusting the relative position of the lens and the image sensor. It has been done.

In the conventional flange back adjustment mechanism 1 shown in FIG. 11, a leaf spring 6 is inserted between a chassis 3 in a camera housing 2 and a holder 5 for holding an image pickup device 4, and a tip end of the holder 5 is provided. An adjusting ring 7 for locking is fitted on the front surface of the camera housing 2 so as to be rotatable and movable back and forth. A female screw is formed on the inner peripheral surface of the adjustment ring 7, and this female screw is screwed onto a male screw on the outer peripheral surface of the fixed cylinder 8 having one end fixed to the chassis 3. The lens barrel 9 is of the CS mount type, and can be mounted on the camera housing 2 by screwing a male screw portion 10 projecting at the end thereof into a female screw formed on the inner peripheral surface of the fixed barrel 8. it can. When adjusting the flange back, insert a finger into the gap between the flange 11 on the end surface of the lens barrel 9 and the end surface of the camera housing 2, rotate the adjustment ring 7, and move the holder 5 back and forth by the adjustment ring 7. Then, the distance L between the flange 11 and the image sensor 4, that is, the flange back is adjusted. Since the CS mount type lens barrel 9 is used here, the flange back L is set to 12.5 mm.

[0004]

[Problems to be solved by the device]

 When adjusting the flange back, the conventional flange back adjustment mechanism 1 rotates the adjustment ring 7 by inserting a finger into a narrow gap between the flange 11 on the end surface of the lens barrel 9 and the end surface of the camera housing 2. Therefore, there is a problem that the turning operation of the adjusting ring 7 is not easy because of this, and it is difficult to make fine adjustments. Also, when the C-mount type lens barrel, which has been widely used so far, is mounted on the camera housing 2, it is necessary to adjust the flange back L'to the specified 17,526 mm. Since the flange back adjustment mechanism 1 of FIG. 1 does not have a structure in which the image sensor 4 can be moved until the flange back difference D of 5.026 mm caused by the lens mount method is filled even if the adjustment ring 7 is rotated to the limit. , Had to use a special adapter. That is, when the C-mount type lens barrel 12 is attached to the camera housing 2, as shown in FIG. 12, between the fixed barrel 8 of the camera housing 2 and the male screw portion 13 of the lens barrel 12. It was necessary to interpose the adapter 14 in between and absorb the flange back difference D. Therefore, the conventional flange-back adjusting mechanism 1 requires the adapter 14 that is attached to and detached from the camera housing 2 according to the lens mount method, and when the adapter 14 is attached, the lens barrel 12 and the camera housing 2 are attached. However, there was a problem that a wasted space was created only for the purpose of absorbing the flange back difference D between the two. Furthermore, for camera housings already on the market for the C-mount method, it is physically necessary to make the adapter compatible with the CS-mount method with an adapter for absorbing the flange-back difference due to the size of the flange-back. Therefore, the method of using this kind of adapter has a problem that it has only one-way compatibility.

[0005]

[Means for Solving the Problems]

 This invention solves the above-mentioned problems, and in a flange back adjustment mechanism that adjusts the distance from the flange, which is the reference surface for mounting the lens barrel to the camera housing, to the image sensor in the camera housing, It is characterized in that it is provided with an image sensor displacement means which operates in response to an operation, and displaces the image sensor with a maximum stroke as a distance exceeding a difference in flange back which differs depending on a lens mounting method.

[0006]

[Action]

 This invention is a camera housing of a lens barrel by displacing the image pickup device by using an image pickup device displacing means that operates in response to an external operation, with a maximum distance that exceeds the difference between flange backs that differ depending on the lens mount method. The distance from the flange, which is the reference surface for mounting to the camera, to the image sensor in the camera housing can be adjusted accurately for all lens mount methods.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. FIGS. 1 and 2 are sectional views showing the states of the first embodiment of the flange back adjusting mechanism of the present invention when the C mount lens and the CS mount lens are attached, respectively.

In the flange back adjustment mechanism 41 shown in FIGS. 1 and 2, an image pickup element 42 is provided in a camera housing 43 so as to be movable back and forth. A moving cam 44 and an adjusting screw 45 for driving the swing cam 44 from the outside are used. The adjusting screw 45 is screwed into the camera housing 43, and its tip is in contact with the back surface of the swing cam 44. The swing cam 44 is swingable about a support shaft 46 over a fixed angle range, and its semicircular tip end is in contact with a holder 47 holding the image pickup element 42. The holder 47 is slidably held in the guide cylinder 48 in the axial direction, and is biased rearward by a leaf spring 49 screwed to the tip thereof. FIG. 1 shows a state in which a C-mount lens is attached. In this state, the adjustment screw 45 is screw-fed up and down within a range of several pitches, so that a flange based on an assembly error at the time of manufacture is produced. The back gap can be adjusted. In addition, FIG. 2 shows a state in which the CS mount lens is attached. In this state, the adjustment screw 45 is screw-fed up and down within a range of about several pitches, so that an assembly error in manufacturing may occur. The deviation of the flange back can be adjusted.

As described above, the flange back adjustment mechanism 41 mounts the swing distance of the swing cam 44 swinging in the camera housing 43 on the camera housing 43 such as the C mount method or the CS mount method. It is possible to drastically switch the flange back according to the lens mount method by adjusting the adjusting screw 45 to drive the swing cam 44 by ensuring the flange back difference D or more depending on the type of lens barrel to be used. Further, by finely moving the adjusting screw 45, the swing cam 44 is slightly swung, and the flange back can be finely adjusted. Furthermore, since the image pickup device 42 is moved back and forth from the inner side of the camera housing 43, no adapter or adjustment ring is required between the camera housing 43 and the lens barrel, and the entire mechanism is compact. Is possible.

The flange back adjustment mechanism 51 shown in FIG. 3 is configured so that the image pickup device 54 can be moved back and forth inside the camera housing 53 when the adjustment ring 52 is rotated. The holder 55 for holding the image pickup element 54 has both wings 55a integrated with the back surface of a tubular cam 56 biased forward by a leaf spring 59a by screwing, and is engraved on the outer peripheral surface of the tubular cam 56. The engaging projections 58 of the adjusting ring 52 are engaged with the formed guide groove 57 at two positions. The engaging projections 58 are provided on the inner peripheral surface of the adjusting ring 52 so as to be opposed to each other, and the guide grooves 57 have two introduction grooves 57a for the engaging projections 58, as shown in FIG. From a Y-shaped branch, a steep sloped groove 57c following the gentle sloped groove 57b, and a gentle sloped groove 57d following the steep sloped groove 57c. The total length of the inclined grooves 57b, 57c, 57d in the circumferential direction is 90 degrees in terms of the circumferential angle of the tubular cam 56. Therefore, when the adjusting ring 52 is rotated exactly 1/4, The engagement protrusion 58 moves from the highest point to the lowest point of the guide groove 57. Further, the projection distance in the axial direction of the steeply inclined groove 57c is set to a length substantially equal to the flange back difference D due to the difference in lens mounting method. Further, the holder 55 for holding the image pickup device 54 has its end portion prevented from rotation by a guide tube 60 with a slit fixed to the chassis 59, and the upper surface of the holder 55 is guided along the inner wall of the slit 60a. I'm doing it. The leaf spring 59a is located between the chassis 59 and the tubular cam 56 and biases the tubular cam 56 forward.

By the way, when the C-mount lens is mounted, as shown in FIG. 5, first, the engaging projection 58 is engaged with the highest point of the proposed groove 57, and the flange back is set to an approximate value. By adjusting the engaging position of the engaging protrusion 58 in the gently inclined groove 57b, the adjustment of the flange back can be performed. On the other hand, when mounting the CS mount lens, as shown in FIG. 6, first, the engaging protrusion 58 is engaged with the lowest point of the guide groove 57, and the flange back is set to an approximate value and then loosened. By adjusting the engaging position of the engaging protrusion 58 in the inclined groove 57d, the flange back can be adjusted.

As described above, the flange-back adjusting mechanism 51 includes the adjusting ring 52 in which the engaging protrusion 58 engages with the guide groove 57 of the tubular cam 56, and the engaging protrusion 58 extends along the guide groove 57 to a stable point. By rotating it so that it slides, it is possible to freely change the flange back according to the lens mount system and adjust the characteristics thereafter, with the adjustment efficiency according to the inclination of the guide groove 57. The stable point formed on the surface makes adjustment easier and is suitable for general use.

In the flange back adjustment mechanism 61 shown in FIGS. 7 and 8, the image pickup element 64 can be moved back and forth by rotating an adjustment ring 63 provided immediately in front of the camera housing 62. The image pickup device 64 is fixed to a displacement member 65 having a thread on its outer periphery, and both ends of a leaf spring 66 screwed to both wings 65a of the displacement member 65 are engaged with the chassis 67 to move forward. Being energized. The displacement member 65 is made of a flat plate-shaped body, and a male screw formed on the outer circumference is screwed into a female screw formed on the inner circumference of the adjustment ring 63. A guide tube 68 with a slit whose front end surface serves as a lens seat is inserted through the inside of the adjustment ring 63, and its end is screwed to the chassis 67. The adjusting ring 63 receives the force of the leaf spring 66 and abuts against and engages with the flange portion 68b of the guide cylinder 68, and the forward displacement is restricted by the flange portion 68b. The displacing member 65 has its upper and lower surfaces engaged with the inner wall of the slit 68a formed in the guide tube 68, whereby only the forward / backward movement is possible and the rotation is impossible. Therefore, when the adjusting ring 63 is rotated, the displacement member 65 is screw-fed and moves in the front-rear direction along the slit 68a of the guide tube 68. In the case of the embodiment, the length of the slit 68a of the guide tube 68 is a length obtained by adding the distance required for fine adjustment to the flange back difference D between the C mount lens and the CS mount lens. Further, the protrusion in front of the camera housing 62 has a very short length in which the thickness of the lens seat is added to the thickness of the operation portion 63a of the adjustment ring 63, and therefore the protrusion is smaller than that of the conventional flange back adjustment mechanism. , The whole can be made more compact.

As described above, the flange-back adjusting mechanism 61 allows the displacement member 65 to move back and forth and rotate when the adjustment ring 63 screwed to the displacement member 65 integrated with the imaging element 64 is rotated. By immovably screw-feeding, the displacement member 65 moves only in the direction necessary for adjusting the flange back, so that the flange back can be adjusted with screw-feed accuracy. Further, since the displacement amount of the displacement member 65 is ensured to be equal to or greater than the flange back difference D which differs depending on the type of the lens barrel mounted on the camera housing 62 such as the C mount method or the CS mount method, it is a flange back adjustment adjustment. Not only that, but the flange back can be changed significantly according to the lens mounting method. Further, the holder 65 holding the image pickup device 64 is biased forward by the plate spring 66, and the spring force transmitted to the adjusting ring 63 is received by the flange portion 68b of the guide tube 68 fixed to the chassis 67. The adjusting ring 63 is always abutted and locked on the collar portion 68b, so that the adjusting ring 63 can always be rotated at the same position without rattling.

The flange-back adjusting mechanism 71 shown in FIGS. 9 and 10 is configured such that the upper and lower blades 74a of a holder 74 holding an image pickup element 73 are fixed to the ends of a cylindrical displacement member 72 having a screw formed on the inner periphery thereof to perform displacement. By rotating the adjusting ring 75 screwed to the member 72, the image pickup device 73 can be moved back and forth together with the displacement member 72. However, in order to prevent the image pickup element 73 from rotating, the upper and lower blades 74a of the holder 74 are engaged with the slits 76a formed longitudinally on the end surface of the guide cylinder 76 that penetrates the adjustment ring 75 and the displacement member 72. .. Further, in the embodiment, the left and right wings 74b of the holder 74 are screwed to the center of the leaf spring 77, and both ends of the leaf spring 77 are locked to the back surface of the chassis 78 to urge the holder 74 backward. is there. Therefore, the adjustment ring 75 is biased rearward by the force of the leaf spring 77, and the end face of the collar-shaped operation portion 75a is brought into contact with and locked to the front surface portion 79a of the camera housing 79. It is positioned so that it cannot be displaced rearward.

Also in this embodiment, when the adjusting ring 75 screwed into the displacement member 72 with which the image pickup device 73 is integrated is rotated, the displacement member 72 is screwed so as to be movable back and forth and non-rotatably. The flange back can be adjusted with the accuracy of screw feed by displacing only in the direction necessary for adjusting the flange back. Further, since the displacement amount of the displacement member 72 is ensured to be equal to or larger than the flange back difference D which differs depending on the type of the lens barrel mounted on the camera housing 79 such as the C mount method or the CS mount method, the flange back adjustment is performed. Of course, it is possible to change the flange back significantly according to the lens mount method. Further, the holder 74 holding the image pickup device 73 is biased rearward by the leaf spring 77, and the spring force transmitted to the adjusting ring 75 is received by the front surface portion 79a of the camera housing 79. The adjustment ring 75 is always abutted and fixed to the front surface portion 79a, so that the adjustment ring 75 can always be rotated at the same position without rattling.

[0017]

[Effect of the device]

 As described above, according to the present invention, the image pickup element displacement means, which operates in response to an external operation, is configured to displace the image pickup element with a maximum distance that exceeds the difference in flange back depending on the lens mount method. The distance from the flange, which is the reference surface for mounting the lens barrel to the camera housing, to the image sensor in the camera housing can be adjusted accurately for all lens mounting methods. Regardless of the type of lens barrel mounted on the camera housing, such as the C-mount method or the CS-mount method, it is possible to obtain an excellent effect such as always obtaining a proper flange back.

Further, according to this invention, a cam for swinging an image pickup device back and forth by swinging is provided in the camera housing so as to be swingable, and an adjusting member for operating the swing position of the cam by being operated from outside the camera housing is provided. Therefore, by adjusting the swing distance of the cam that swings inside the camera housing to more than the difference in flange back that differs depending on the type of lens barrel mounted on the camera housing, such as the C mount method or CS mount method, adjustment is possible. By adjusting the member and swinging the cam, it is possible to change the flange back significantly according to the lens mount system.On the other hand, by slightly moving the adjusting member to slightly swing the cam, the flange back Fine adjustment is possible and the structure is such that the image sensor is moved back and forth from the inner side of the camera housing.Therefore, an adapter or adjustment is provided between the camera housing and the lens barrel. It does not require a straightening ring, and has excellent effects such as making the entire mechanism compact.

Further, according to this invention, a cylindrical cam having a guide groove on the outer peripheral surface is provided in the camera housing in a state where the image pickup device is attached, and an engaging projection protruding on the inner peripheral surface is provided in the above proposal. Since the adjustment ring is arranged in the front part of the camera housing in the state of being engaged with the groove, and the flange ring is adjusted by displacing the cam back and forth by rotating the adjustment ring from the outside. By rotating the adjustment ring that engages the engaging projection with the guide groove of the cam so that the engaging projection slides along the guide groove to a stable point, the flange back can be greatly adjusted according to the lens mount method. From the switching to the subsequent adjustment, it is possible to freely adjust with the adjustment efficiency according to the inclination of the guide groove, and the stable point formed in the guide groove serves as a guide for adjustment, so it is particularly suitable for general use. Excellent effect .

Further, according to the present invention, the displacement member is provided in the camera housing so as to be movable back and forth in a state where the image pickup device is fixed, and the guide member prevents the displacement member from rotating and is screwed to the displacement member. Since the adjustment ring is installed in the front of the camera housing so that it cannot be displaced forward or backward, and the adjustment ring is rotated from the outside to displace the displacement member back and forth to adjust the flange back, When the adjustment ring screwed to the displacement member integrated with the element is rotated to screw-feed the displacement member, the displacement member is in a state in which it can move back and forth but cannot rotate. The displacement member moves only in the direction necessary for adjusting the flange back, which allows the flange back to be adjusted with screw feed accuracy, and the displacement amount of the displacement member can be changed between the C mount method and the CS mount method. By securing more than the difference in flange back that differs depending on the type of lens barrel attached to the camera housing, not only adjustment of the flange back but also drastic change of the flange back according to the lens mounting method can be performed. It is also possible to further regulate the adjustment ring to the same position by urging the displacement member holding the image sensor forward, for example, by a spring, while regulating the adjustment ring so that it cannot be displaced forward. The adjustment ring can be rotated in position without rattling, and conversely, the displacement ring holding the image sensor is biased forward by a spring while restricting the adjustment ring so that it cannot be displaced backward. Even with this, there is an effect that the adjustment ring can always be rotated at the same position without play.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state where a C-mount lens of a first embodiment of a flange back adjustment mechanism of the present invention is attached.

FIG. 2 is a cross-sectional view showing a state when the CS mount lens of the flange back adjustment mechanism shown in FIG. 1 is attached.

FIG. 3 is an exploded perspective view showing a second embodiment of the flange back adjustment mechanism of the present invention.

4 is a development view of a guide groove of the tubular cam shown in FIG.

5 is a cross-sectional view showing a state where the C-mount lens of the flange back adjustment mechanism shown in FIG. 3 is attached.

6 is a cross-sectional view showing a state when the CS mount lens of the flange back adjustment mechanism shown in FIG. 3 is attached.

FIG. 7 is an exploded perspective view showing a third embodiment of the flange back adjusting mechanism of the present invention.

8 is a sectional view of the flange back adjustment mechanism shown in FIG.

FIG. 9 is an exploded perspective view showing a fourth embodiment of the flange back adjustment mechanism of the present invention.

10 is a cross-sectional view of the flange back adjustment mechanism shown in FIG.

FIG. 11 is a CS of an example of a conventional flange back adjustment mechanism.
It is sectional drawing which shows the state at the time of mounting a mount lens.

FIG. 12 C of the flange back adjustment mechanism shown in FIG.
It is sectional drawing which shows the state at the time of mounting a mount lens.

[Explanation of symbols]

 41, 51, 61, 71 Flange back adjusting mechanism 43, 53, 62, 79 Camera housing 42 54, 64, 73 Image sensor 44 Swing cam 45 Adjusting screw 52, 63, 75 Adjusting ring 56 Cylindrical cam 57 Guide groove 58 Engagement projection 65,72 Displacement member 66,77 Leaf spring 68,76 Guide tube

Claims (4)

[Scope of utility model registration request] 1. A flange-back adjusting mechanism for adjusting a distance from a flange, which is a reference surface for mounting a lens barrel to a camera housing, to an image pickup device in the camera housing, which operates in response to an external operation and operates by a lens mount system. The maximum stroke is the distance that exceeds the difference in flange back depending on
A flange back adjustment mechanism comprising an image sensor displacement means for displacing the image sensor. 2. The image pickup device displacing means is swingably provided in the camera casing, and is operated from outside the camera casing by a cam that moves the image pickup device back and forth by swinging.
The flange-back adjusting mechanism according to claim 1, further comprising an adjusting member that adjusts a swing position of the cam. 3. The image pickup element displacing means is located inside the camera housing, has the image pickup element attached along a central axis, has a cylindrical cam having a guide groove on an outer peripheral surface, and projects on an inner peripheral surface. An adjusting ring which is arranged in a front portion of the camera housing in a state where the provided engaging projection is engaged with the guide groove, and which displaces the cam back and forth when the cam is rotated from the outside. The flange back adjustment mechanism according to claim 1, wherein 4. The member for displacing the image pickup device, a member for displacing the inside of the camera casing together with the image pickup device, a guide cylinder for guiding the member in a non-rotatable manner, and a member for being inserted into and removed from the guide cylinder.
2. An adjustment ring, which is disposed on the front part of the camera housing so as not to be displaced forward or backward, and which displaces the image pickup device forward and backward when it is rotated from the outside. Flange back adjustment mechanism.