Optical device and imaging apparatus

Abstract

To provide an optical device that has rigidity despite its small size.SOLUTION: An optical device has: a stationary barrel that is provided with first and second straight advance grooves; a cam barrel that is arranged on an outer diameter side of the stationary barrel, and is provided with first and second cam grooves; a first movable barrel that holds a first optical element; and a second movable barrel that holds a second optical element closer to an image side than the first optical element. The first movable barrel includes first and second straight advance rollers that are engaged with the first straight advance groove, and a first cam roller that is engaged with the first cam groove. The second movable barrel includes a third straight advance roller that is engaged with the second straight advance groove, and a second cam roller that is engaged with the second cam groove. The first straight advance roller is provided at a first attachment part on an outer peripheral surface of the first movable barrel. The second straight advance roller is provided at a second attachment part closer to the image side than the first attachment part on the outer peripheral surface of the first movable barrel. The distance from an optical axis to the first attachment part is longer than the distance from the optical axis to the second attachment part. The length in a radial direction of the first straight advance roller is shorter than the length in the radial direction of the second straight advance roller.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an optical device and an imaging device. [Background technology]

[0002] In recent years, with the trend toward higher definition images, lenses are also required to have high optical performance. However, if the lens holder frame is tilted, it is difficult to obtain high optical performance. Patent documents 1 and 2 propose a structure to suppress the tilt of the lens holder frame, in which multiple rollers that engage with linear grooves are arranged in the optical axis direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-114799 A [Patent Document 2] JP 2014-153618 A Summary of the Invention [Problem to be solved by the invention]

[0004] As shooting styles become more diverse, lens portability is becoming more important, and there is a demand for even smaller lenses. However, in the structures of Patent Documents 1 and 2, the lens holding frame becomes long in the optical axis direction, so in a structure in which multiple lens holding frames are close to each other, it is necessary to provide a large notch in the lens holding frame to avoid interference between the lens holding frames, which reduces the rigidity of the lens holding frame.

[0005] In addition, in the case of a lens configuration in which the height of the light rays decreases toward the image side, the diameter difference between the linear roller mounting part on the image side and the lens on the image side becomes large, and the space between them needs to be connected by a mechanical structure, which increases the mass of the lens barrel and leads to an increase in the size of the lens barrel. SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide an optical device that is small yet has sufficient rigidity. [Means for solving the problem]

[0006] In order to achieve the above object, an optical device includes a fixed barrel provided with a first rectilinear groove and a second rectilinear groove extending in an optical axis direction, a cam barrel disposed on the outer diameter side of the fixed barrel and provided with a first cam groove and a second cam groove, a first movable barrel disposed on the inner diameter side of the fixed barrel and holding a first optical element, and a second movable barrel disposed on the inner diameter side of the fixed barrel and holding a second optical element located on an image side of the first optical element, the first movable barrel including first rectilinear rollers and second rectilinear rollers that engage with the first rectilinear groove, and a first cam roller that engages with the first cam groove, The second movable barrel includes a third linear roller that engages with the second linear groove and a second cam roller that engages with the second cam groove, the first linear roller is provided at a first mounting portion on the outer circumferential surface of the first movable barrel, and the second linear roller is provided at a second mounting portion on the outer circumferential surface of the first movable barrel that is closer to the image side than the first mounting portion, the distance from the optical axis to the first mounting portion is longer than the distance from the optical axis to the second mounting portion, and the radial length of the first linear roller is shorter than the radial length of the second linear roller. Effect of the Invention

[0007] According to the present invention, it is possible to provide an optical device that is small in size yet has rigidity. [Brief description of the drawings]

[0008] [Figure 1] 1 is a partial cross-sectional view of an optical device according to a first embodiment. [Diagram 2] 1 is a partial cross-sectional view of an optical device according to a first embodiment. [Diagram 3] 1 is a partial cross-sectional view of an optical device according to a first embodiment. [Figure 4] FIG. 11 is a partial cross-sectional view of an optical device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Note that the following examples do not limit the configuration of the present invention. In addition, although a plurality of features are described in this embodiment, not all of these features are necessarily required, and a plurality of features may be combined in any desired manner. Furthermore, in the accompanying drawings, the apparatus according to this embodiment is drawn at a scale different from the actual scale in order to facilitate understanding of the apparatus, and the same or similar components are given the same reference numerals, and duplicated descriptions are omitted. Note that in the drawings, the left side corresponds to the object side, and the right side corresponds to the image side. EXAMPLES

[0010] A lens device (optical device) 100 according to a first embodiment will be described with reference to FIGS. FIG. 1 is a partial cross-sectional view including an optical axis 50 at a first phase about an optical axis 50 of a lens device 100 according to a first embodiment. A cam barrel 2 is disposed on the outer periphery (outer diameter side) of the fixed barrel 1 in engagement with the fixed barrel 1 so as to be rotatable around an optical axis 50. The image side end of the cam barrel 2 is biased toward the object side by a cam barrel retainer 3 so that the object side end is pressed against the fixed barrel 1 in the direction of the optical axis 50 in the figure. A first movable barrel 5 is disposed on the inner diameter side of the fixed barrel 1, and the first movable barrel 5 retains a first lens (first optical element) 14 by a lens retaining structure such as a retaining ring. A lens retaining barrel 7 retaining a second lens (second optical element) 15 is fixed to the second movable barrel 6 by a screw (not shown). In this embodiment, the first movable barrel 5 and the second movable barrel 6 are described as retaining lenses, but the present invention is not limited to this, and other optical elements such as a filter and an aperture stop may be retained.

[0011] The first moving barrel 5 is provided with a plurality of first rectilinear roller pairs 8 (e.g., in three or more phases) in the direction of the optical axis 50 and in the circumferential direction around the optical axis 50. The first rectilinear roller pairs 8 are engaged with a first rectilinear groove pair (corresponding to the "first rectilinear groove" in the claims) 12 provided in the fixed barrel 1. The first rectilinear roller pairs 8 are composed of a first rectilinear roller 8a and a second rectilinear roller 8b spaced apart from each other in the direction of the optical axis 50, and are provided in three pairs in three phases (first phases) at intervals of approximately 120 degrees around the optical axis 50. The first rectilinear groove pairs 12 of the fixed barrel 1 are composed of a first rectilinear groove 12a and a second rectilinear groove 12b spaced apart from each other in the direction of the optical axis 50, and are provided in three pairs in three phases (first phases) at intervals of approximately 120 degrees around the optical axis 50. The first linear rollers 8a and the second linear rollers 8b are engaged with the corresponding first linear grooves 12a and second linear grooves 12b, respectively. Figure 1 shows a partial cross-sectional view of the lens barrel in one of the first phases.

[0012] FIG. 2 is a partial cross-sectional view of the lens barrel including the optical axis 50 of the lens device 100 according to the first embodiment in a second phase that is different from the first phase around the optical axis 50. In the second moving barrel 6, a plurality of second rectilinear roller pairs 9 are arranged in the direction of the optical axis 50 and in the circumferential direction around the optical axis 50 (for example, in three or more phases). The second rectilinear roller pairs 9 are engaged with a second rectilinear groove pair (corresponding to the "second rectilinear groove" in the claims) 13 provided in the fixed barrel 1. The second rectilinear roller pairs 9 are configured by providing three pairs of second rectilinear roller pairs consisting of a third rectilinear roller 9a and a fourth rectilinear roller 9b spaced apart from each other in the direction of the optical axis 50 in three phases (second phases) at intervals of approximately 120 degrees around the optical axis 50. The second rectilinear groove pairs 13 of the fixed barrel 1 are configured by providing three pairs of third rectilinear grooves 13a and fourth rectilinear grooves 13b spaced apart from each other in the direction of the optical axis 50 in three phases (second phases) at intervals of approximately 120 degrees around the optical axis 50. The third rectilinear rollers 9a and the fourth rectilinear rollers 9b are engaged with the corresponding third rectilinear grooves 13a and fourth rectilinear grooves 13b, respectively. Figure 2 shows a partial cross-sectional view of the lens barrel in one of the second phases.

[0013] The first moving barrel 5 and the second moving barrel 6 are each provided with a plurality of first cam rollers and second cam rollers (not shown) in the circumferential direction centered on the optical axis 50, which engage with a first cam groove 10 and a second cam groove 11 provided in the cam barrel 2, respectively. The operation barrel 4 engages with the outer periphery of the cam barrel 2 so as to be rotatable around the optical axis 50, and is connected to the cam barrel 2 by a connecting structure (not shown). Due to a linear motion mechanism formed by the first rectilinear groove pair 12, the second rectilinear groove pair 13, the first cam groove 10, and the second cam groove 11, when the operation barrel 4 is rotated, the first moving barrel 5 and the second moving barrel 6 move in the direction of the optical axis 50, and the optical performance changes.

[0014] The positions of the object side rectilinear roller mounting portion 18a and the image side rectilinear roller mounting portion 18b, which are the positions where the first rectilinear roller pair 8a and the second rectilinear roller pair 8b are fixed to the first moving barrel 5, differ in height (distance) from the optical axis 50. Specifically, the height (distance) from the optical axis 50 of the outer circumferential surface of the first moving barrel 5 to which the first rectilinear roller pair 8 is fixed is lower for the image side rectilinear roller mounting portion (second mounting portion) 18b than for the object side rectilinear roller mounting portion (first mounting portion) 18a. This allows the sliding portion between the second rectilinear roller 8b and the second rectilinear groove 12b to be lower (closer to the optical axis 50), and further allows a step to be provided in the fixed barrel 1 to reduce the outer diameter on the image side.

[0015] In the optical axis direction, a first lens 14 held by the first movable cylinder 5 and a second lens 15 held by the second movable cylinder 6 are arranged in this order from the object side to the image side. The first lens 14 is held on the object side within the extension range of the first movable cylinder 5 in the optical axis direction, and the second lens 15 is held on the image side within the extension range of the second movable cylinder 6 in the optical axis direction. In this configuration, a part of the image side of the first movable cylinder 5 and a part of the object side of the second movable cylinder 6 are configured to be nested inside each other so that the first movable cylinder 5 is located on the inner diameter side of the second movable cylinder 6.

[0016] The length of the first linear roller 8a projecting radially from the object side linear roller mounting portion 18a is shorter than the length of the second linear roller 8b projecting radially from the image side linear roller mounting portion 18b. Here, the "radial length" refers to the "radial distance from the mounting portion (outer circumferential surface) to the end of the linear roller (the maximum value if it varies depending on the location)". This allows the image side linear roller mounting portion 18b of the first moving barrel 5 to be positioned on the inner diameter side of the image side linear roller mounting portion 19b of the second moving barrel 6. The second moving barrel 6 is provided with a through hole 21 penetrating in the radial direction and extending in the direction of the optical axis 50 in order to avoid interference with the second linear roller 8b of the first moving barrel 5. The second linear roller 8b of the first moving barrel 5 engages with the second linear groove 12b provided in the fixed barrel 1 via the through hole 21 of the second moving barrel 6. In the case of the conventional techniques disclosed in Patent Documents 1 and 2, it was necessary to provide a large notch in the second movable cylinder 6 to avoid interference with the movable cylinder, but in this embodiment, a hole is provided that penetrates the second movable cylinder 6 radially, thereby ensuring the rigidity of the second movable cylinder 6.

[0017] By ensuring the length in the optical axis direction of the first moving barrel 5, which allows the first rectilinear rollers 8a and the second rectilinear rollers 8b to be spaced apart in the optical axis direction, it is possible to reduce the tilt of the first lens 14. Also, by ensuring the length in the optical axis direction of the second moving barrel 6, which allows the third rectilinear rollers 9a and the fourth rectilinear rollers 9b to be spaced apart in the optical axis direction, it is possible to reduce the tilt of the second lens 15. Also, because the first moving barrel 5 and the second moving barrel 6 are configured in a nested manner, it is possible to achieve a compact lens barrel while ensuring the length in the optical axis direction of the first moving barrel 5 and the second moving barrel 6.

[0018] FIG. 3 is a partial cross-sectional view including the optical axis 50 of the lens device 100 according to the first embodiment in a third phase that is different from the first phase and the second phase about the optical axis 50. The outer periphery of the first moving barrel 5 is provided with pins 16a at multiple phases centered on the optical axis 50, and the outer periphery of the second moving barrel 6 is provided with pins 16b at multiple phases centered on the optical axis 50. The pins 16a and 16b are arranged in three phases (third phases) at intervals of approximately 120 degrees around the optical axis 50, in phases different from the first phase around the optical axis 50 in which the first rectilinear roller pair 8 is provided and the second phase around the optical axis 50 in which the second rectilinear roller pair 9 is provided. FIG. 3 shows a partial cross-sectional view of the lens barrel in one of the third phases.

[0019] Between the pins 16a and 16b, an elastic member 17 is provided that constantly applies an elastic force to the first moving barrel 5 and the second moving barrel 6 in a direction that moves them closer to or farther from each other. The elastic member 17 biases the first moving barrel 5 and the second moving barrel 6 in the optical axis direction, and can suppress (remove) tilting due to a backlash (gap) that occurs between the cam roller and the cam groove, and between the linear roller and the linear groove. In the first embodiment, a tension spring as the elastic member 17 is configured to engage with the pins 16a and 16b, but this is not limited thereto, and a compression spring may be disposed so that a compression force acts in a direction that moves the pins 16a and 16b away from each other. The above structure makes it possible to realize a compact lens while ensuring the rigidity of the movable barrel. EXAMPLES

[0020] Second embodiment: A lens device (optical device) 200 according to a second embodiment will be described with reference to Fig. 4. Fig. 4 is a partial cross-sectional view including the optical axis of the lens device 200 according to the second embodiment. In the first embodiment, the two first rectilinear groove pairs 12 aligned in the optical axis direction with which the first rectilinear roller pair 8 fixed to the first moving barrel 5 engages, and the two second rectilinear groove pairs 13 aligned in the optical axis direction with which the second rectilinear roller pair 9 fixed to the second moving barrel 6 engages are arranged in different phases from each other. In contrast, in the second embodiment, the first rectilinear groove 12a and the third rectilinear groove 13a are shared as the object side rectilinear groove 20a, and are configured as one rectilinear groove. The second rectilinear groove 12b and the fourth rectilinear groove 13b are shared as the image side rectilinear groove 20b, and are configured as one rectilinear groove. In addition, the object side rectilinear groove 20a and the image side rectilinear groove 20b are arranged in the same phase. That is, the object side rectilinear groove 20a with which the first rectilinear rollers 8a and the third rectilinear rollers 9a engage is in phase with the image side rectilinear groove 20b with which the second rectilinear rollers 8b and the fourth rectilinear rollers 9b engage, and the phases around the optical axis are the same. In this embodiment, three linear groove pairs each consisting of the object side rectilinear groove 20a and the image side rectilinear groove 20b arranged in the same phase are included, and these three linear pairs are arranged in different phases from each other in the circumferential direction.

[0021] By adopting this structure, the number of linear grooves provided in the fixed barrel 1 can be reduced. In the first embodiment, the fixed barrel 1 has 12 linear grooves (six for the first moving barrel and six for the second moving barrel), whereas in the second embodiment, the number can be reduced to six. This increases the strength of the fixed barrel 1, thereby improving reliability, and reduces the number of grooves, thereby reducing processing costs. When linear grooves are formed in common on the same phase, the movement ranges of the first moving barrel 5 and the second moving barrel 6 in the optical axis direction may be restricted by interference between the movable ranges of the linear rollers of each barrel. Therefore, it is advisable to adopt common linear grooves in consideration of the optical specifications of the lens device.

[0022] A lens device having the lens barrel of the present invention can be provided that enjoys the effects of the present invention. Also, an imaging device having the lens device having the lens barrel of the present invention and an imaging device having an imaging element that receives an image formed by the lens device can be provided that enjoys the effects of the present invention.

[0023] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention.

[0024] The disclosure of this embodiment includes the following configuration. (Configuration 1) a fixed barrel provided with a first rectilinear groove and a second rectilinear groove extending in the optical axis direction; a cam barrel disposed on an outer diameter side of the fixed barrel and having a first cam groove and a second cam groove; a first movable barrel arranged on an inner diameter side of the fixed barrel and holding a first optical element; a second movable barrel that is disposed on an inner diameter side of the fixed barrel and holds a second optical element that is closer to an image side than the first optical element; the first moving barrel includes a first linear roller and a second linear roller that engage with the first linear groove, and a first cam roller that engages with the first cam groove, the second moving barrel includes a third linear roller that engages with the second linear groove and a second cam roller that engages with the second cam groove, The first linear roller is provided on a first mounting portion on an outer circumferential surface of the first movable cylinder, the second linear roller is provided on a second mounting portion on an outer circumferential surface of the first moving barrel, the second mounting portion being closer to the image side than the first mounting portion; a distance from an optical axis to the first mounting portion is longer than a distance from the optical axis to the second mounting portion; An optical device, wherein a length in a radial direction of the first linear roller is shorter than a length in a radial direction of the second linear roller. (Configuration 2) At least a portion of the first movable barrel is located on an inner diameter side of the second movable barrel, The optical device according to configuration 1, wherein the second moving cylinder has a through hole penetrating in a radial direction, and the second linear roller engages with the first linear groove via the through hole. (Configuration 3) 2. The optical device according to configuration 1, wherein the first linear rollers and the second linear rollers are arranged in the same phase in the circumferential direction. (Configuration 4) The optical device described in configuration 3, characterized in that the first movable cylinder includes three first linear roller pairs each consisting of the first linear roller and the second linear roller, and the three first linear roller pairs are arranged at different phases from each other in the circumferential direction. (Configuration 5) 2. The optical device according to configuration 1, wherein the second moving barrel includes a fourth rectilinear roller that engages with the second rectilinear groove and is disposed closer to the image side than the third rectilinear roller. (Configuration 6) The optical device according to configuration 5, wherein the third linear rollers and the fourth linear rollers are arranged in the same phase in the circumferential direction. (Configuration 7) The optical device described in configuration 6, characterized in that the second movable cylinder includes three second linear roller pairs each consisting of the third linear roller and the fourth linear roller, and the three second linear roller pairs are arranged at different phases from each other in the circumferential direction. (Configuration 8) the first moving cylinder includes three first linear roller pairs each consisting of the first linear roller and the second linear roller arranged in the same phase in the circumferential direction, and the three first linear roller pairs are arranged in different phases from each other in the circumferential direction; the second movable barrel includes a fourth rectilinear roller that engages with the second rectilinear groove and is disposed closer to the image side than the third rectilinear roller, the second moving cylinder includes three second linear roller pairs each consisting of the third linear roller and the fourth linear roller arranged in the same phase in the circumferential direction, and the three second linear roller pairs are arranged in different phases in the circumferential direction, The optical device according to configuration 1, wherein the first pair of rectilinear rollers and the second pair of rectilinear rollers are arranged at different phases from each other in the circumferential direction. (Configuration 9) 2. The optical device according to configuration 1, wherein the first rectilinear grooves and the second rectilinear grooves are arranged at different phases from each other in the circumferential direction. (Configuration 10) 2. The optical device according to configuration 1, wherein the first rectilinear grooves and the second rectilinear grooves are configured to be in the same phase with each other in the circumferential direction. (Configuration 11) 2. The optical device according to configuration 1, further comprising an elastic member that biases each of the first moving barrel and the second moving barrel in the optical axis direction. (Configuration 12) 12. The optical device according to configuration 11, wherein the elastic member is a tension spring. (Configuration 13) 12. The optical device according to configuration 11, wherein the elastic member is a compression spring. (Configuration 14) 2. The optical device according to configuration 1, wherein an outer diameter of the first optical element is larger than an outer diameter of the second optical element. (Configuration 15) 15. An imaging device comprising: the optical device according to any one of configurations 1 to 14; and an imaging element that receives an image formed by the optical device. [Explanation of symbols]

[0025] 1: Fixed cylinder 2: Cam barrel 5: First moving tube 6: Second moving tube 8a: First straight roller (first straight roller on the object side) 8b: First straight roller (first straight roller on the image side) 9a: Second straight roller (second straight roller on the object side) 9b: Second straight roller (Second straight roller on the image side) 10: First cam groove 11: Second cam groove 12: First straight groove pair (first straight groove in the claims) 13: Second straight groove pair (Second straight groove in the claims) 14: First lens (first optical element) 15: Second lens (second optical element)

Claims

1. a fixed barrel provided with a first rectilinear groove and a second rectilinear groove extending in an optical axis direction; a cam barrel disposed on an outer diameter side of the fixed barrel and having a first cam groove and a second cam groove; a first movable barrel arranged on an inner diameter side of the fixed barrel and holding a first optical element; a second movable barrel that is disposed on an inner diameter side of the fixed barrel and holds a second optical element that is closer to an image side than the first optical element; the first moving barrel includes a first linear roller and a second linear roller that engage with the first linear groove, and a first cam roller that engages with the first cam groove, the second moving barrel includes a third linear roller that engages with the second linear groove and a second cam roller that engages with the second cam groove, the first linear roller is provided on a first mounting portion on an outer circumferential surface of the first movable cylinder, the second linear roller is provided on a second mounting portion on an outer circumferential surface of the first moving barrel, the second mounting portion being closer to the image side than the first mounting portion; A distance from an optical axis to the first mounting portion is longer than a distance from the optical axis to the second mounting portion; An optical device, characterized in that a length in a radial direction of the first linear roller is shorter than a length in a radial direction of the second linear roller.

2. At least a portion of the first movable barrel is located on an inner diameter side of the second movable barrel, 2. The optical device according to claim 1, wherein the second moving cylinder has a through hole passing therethrough in a radial direction, and the second linear roller is engaged with the first linear groove via the through hole.

3. 2. The optical device according to claim 1, wherein the first linear rollers and the second linear rollers are arranged in the same phase in the circumferential direction.

4. The optical device according to claim 3, characterized in that the first movable cylinder includes three first linear roller pairs each consisting of the first linear roller and the second linear roller, and the three first linear roller pairs are arranged at different phases from each other in the circumferential direction.

5. 2. The optical device according to claim 1, wherein the second moving barrel includes a fourth rectilinear roller that engages with the second rectilinear groove and is disposed closer to the image side than the third rectilinear roller.

6. 6. The optical device according to claim 5, wherein the third rectilinear rollers and the fourth rectilinear rollers are arranged in the same phase in the circumferential direction.

7. The optical device according to claim 6, characterized in that the second movable cylinder includes three second linear roller pairs each consisting of the third linear roller and the fourth linear roller, and the three second linear roller pairs are arranged at different phases from each other in the circumferential direction.

8. the first moving cylinder includes three first linear roller pairs each consisting of the first linear roller and the second linear roller arranged in the same phase in the circumferential direction, the three first linear roller pairs being arranged in different phases from each other in the circumferential direction, the second movable barrel includes a fourth linear roller that engages with the second linear groove and is disposed closer to the image side than the third linear roller, the second moving cylinder includes three second linear roller pairs each consisting of the third linear roller and the fourth linear roller arranged in the same phase in the circumferential direction, and the three second linear roller pairs are arranged in different phases from each other in the circumferential direction; 2. The optical device according to claim 1, wherein the first pair of rectilinear rollers and the second pair of rectilinear rollers are arranged at different phases from each other in the circumferential direction.

9. The optical device according to claim 1 , wherein the first rectilinear grooves and the second rectilinear grooves are arranged at different phases from each other in the circumferential direction.

10. 2 . The optical device according to claim 1 , wherein the first rectilinear grooves and the second rectilinear grooves are configured to be in the same phase with each other in the circumferential direction.

11. 2. The optical device according to claim 1, further comprising an elastic member for biasing each of the first and second movable barrels in the optical axis direction.

12. 12. The optical device according to claim 11, wherein the elastic member is a tension spring.

13. 12. The optical device according to claim 11, wherein the elastic member is a compression spring.

14. The optical device according to claim 1 , wherein an outer diameter of the first optical element is larger than an outer diameter of the second optical element.

15. 15. An imaging apparatus comprising: the optical device according to claim 1; and an imaging element that receives an image formed by the optical device.

Images