Thin aperture control structure applied to imaging device

Abstract

The utility model discloses a thin aperture control structure applied to an imaging device. A variable aperture structure comprises a fixed seat, a turntable, a driving motor, a plurality of blade driving lever groups, a transmission gear and a fixed ring, a through hole communicated with the rotating hole is formed in the middle of the fixing ring, the hole diameter of the through hole is larger than that of the rotating hole, and the rotating disc is exposed in the through hole of the fixing ring; limiting driving levers of the blade driving lever set are installed on the fixing base and are stacked and arranged in sequence, and then the rotating disc is installed on the fixing base. The blade driving lever group forms a light inlet hole; by improving the structural design of the rotating disc and the fixing ring, the rotating disc is directly exposed in the through hole of the fixing ring, the lens of the imaging device can enter the rotating disc through the through hole, the distance between the lens and the blade set is greatly shortened, and the imaging device can be smaller in size, thinner and more compact; and optical errors can be reduced, the detail definition of the image is improved, and the imaging effect is more effectively achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of aperture devices, in particular to a thin aperture control structure applied to an imaging device. Background Art

[0002] Aperture assemblies are used in optical systems to adjust the amount of light passing through, achieving variable aperture functionality. Currently, these assemblies typically utilize a multi-blade structure. This is due to the flexible aperture adjustment range it provides, with each blade controlled by an independent lever. When the aperture opening is at its maximum diameter, the blades retract within the width of the locking cover. Consequently, these multi-blade structures face challenges such as bulk, difficulty fitting into existing spaces, complex assembly and maintenance, difficulty disassembling, noise issues, and difficulties in achieving a thin design. These issues limit the application of aperture assemblies in modern miniaturized and compact devices.

[0003] The existing aperture control structure has many components and is large in size. In addition, the distance between the lens and the blades is too large, making precise adjustment more difficult, affecting the aperture control accuracy and thus the imaging effect. At the same time, in order to accommodate the larger distance between the lens and the blades, the volume of the entire aperture control device needs to be further increased, resulting in low overall integration of the imaging device and difficulty in compact and thin design.

[0004] Furthermore, the multi-blade structure is relatively complex to assemble, requiring each blade to precisely mate with its own independent lever system. This process is not only tedious but also prone to assembly errors. For example, the alignment of the blades, the engagement of the levers, and the adjustment of the drive mechanism all require precise operation, otherwise the normal function of the aperture will be affected.

[0005] Therefore, further research and development is needed to solve the problems existing in the existing technology. Utility Model Content

[0006] Therefore, in order to solve the above-mentioned problems, the purpose of the present invention is to provide a thin aperture control structure for an imaging device, improve the structure of the aperture control device, enable the control structure to achieve space optimization and ultra-thin design, and at the same time make installation simpler and faster.

[0007] The purpose of this utility model is achieved by the following technical solutions:

[0008] A thin aperture control structure for an imaging device includes a fixing base with a rotation hole extending through the middle thereof; a blade assembly, a rotating disk, and a fixing ring for locking the blades and the rotating disk are sequentially mounted on the upper surface of the fixing base;

[0009] A through hole is provided in the middle of the fixing ring and is connected to the rotating hole. The aperture of the through hole is larger than that of the rotating hole. The lens of the imaging device can extend into the turntable through the through hole.

[0010] The blade group is formed by a plurality of arc-shaped blades arranged around the edge of the rotating hole; an integrally formed adjustment lever is provided on the upper surface of one end of the blade, and a plurality of radially arranged strip holes are provided on the rotating disk, and the adjustment lever is passed through the strip holes and moves back and forth; an integrally formed limit lever is provided on the lower surface of the other end of the blade, and a limit hole matching the limit lever is provided on the fixing seat, and the blade is fixed on the fixing seat by inserting the limit lever into the limit hole;

[0011] A plurality of teeth are provided on the outer edge of the turntable, and a driving motor is installed on the lower surface of the fixing seat. The driving motor passes through the fixing seat and is meshed with the teeth of the turntable through a transmission gear for transmission.

[0012] Furthermore, the fixing seat is provided with a first mounting groove for mounting the blade assembly and the turntable on the upper and lower sides, and a second mounting groove for mounting the transmission gear is provided adjacent to one side of the first mounting groove; the fixing ring is designed to cover the top of the first mounting groove.

[0013] Furthermore, the depth of the first mounting groove is greater than the depth of the second mounting groove.

[0014] Furthermore, the inner side wall of the first installation groove is provided with a plurality of limit blocks extending radially toward the turntable, and the outer periphery of the turntable is provided with a limit groove extending along its circumference; when the turntable rotates in the first installation groove, the limit blocks can move along the limit groove.

[0015] Furthermore, a plurality of limit posts are spaced apart on the outer peripheral edge of the fixing seat, and the limit posts extend toward the fixing ring. The edge of the fixing ring is provided with a limit notch matching the limit posts, and the limit posts are located in the limit notch to limit the horizontal displacement of the fixing ring.

[0016] Furthermore, the height of the limiting clamping column is not greater than the thickness of the fixing ring, and the opening edge of the limiting notch is provided with a guide arc surface for guiding the limiting clamping column to enter.

[0017] Furthermore, an arc-shaped positioning piece extending toward the fixed seat is provided on the outer side of the turntable, and the fixed seat is provided with an arc-shaped groove for the positioning piece to move back and forth; the length of the arc-shaped groove is the same as the rotation stroke of the turntable; and a sensing device for sensing the positioning piece is provided on the arc-shaped groove.

[0018] Furthermore, the outer periphery of the fixing seat is provided with a plurality of connecting blocks spaced apart along its circumferential direction, the outer periphery of the fixing ring is provided with a plurality of elastic clips which are clamped and connected with the connecting blocks, the elastic clips are provided with buckle grooves which are adapted to the connecting blocks, and the elastic clips are clamped and fixed with the connecting blocks through the buckle grooves; the end of the connecting block close to the fixing ring is provided with a guide slope inclined toward the direction of the fixing seat.

[0019] Furthermore, deformation notches are respectively provided on both sides of the elastic buckle to increase the deformation force of the elastic buckle.

[0020] Furthermore, the transmission gear is meshed with the teeth of the turntable through a first driven gear and a second driven gear.

[0021] Furthermore, a plurality of locking grooves are provided at intervals on the outer peripheral edge of the fixing ring, and the locking grooves are used to fix the fixing ring on the fixing seat by screws, and the tops of the screws do not protrude outside the fixing ring.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. This utility model improves the structure of the aperture control device, achieving space optimization and an ultra-thin design for the control structure, while also simplifying and speeding up installation. Specifically, by improving the structural design of the turntable and fixed ring, the turntable is directly exposed to the through-hole of the fixed ring, allowing the lens of the imaging device to enter the turntable through the through-hole, greatly shortening the distance between the lens and the blade assembly. This not only makes the imaging device smaller, thinner, and more compact, meeting the requirements of modern equipment for lightness, thinness, and compactness, but also reduces optical errors, improves the clarity of image details, and more effectively achieves imaging effects.

[0024] Furthermore, the shape of the turntable and the depth of the first mounting groove of the fixing seat can be designed according to the specific installation space or structural design requirements of the product to accommodate imaging devices with different lens lengths and more limited installation spaces, with strong adaptability.

[0025] 2. The present invention also optimizes the structure of the blades, integrating the blades, adjustment lever, and limit post into one piece. On the one hand, the integration of the blades, adjustment lever, and limit post saves the riveting process of the traditional aperture control structure, improves the reliability of the integration, avoids the accumulation of tolerances between multiple parts, reduces the motion instability or error caused by assembly errors, and achieves higher precision. On the other hand, the shutter is more compact and quicker to install by simply installing the one-piece blade assembly onto the rotating ring and base, wrapping the blades around the mounting groove of the base, and then installing the turntable.

[0026] 3. In one preferred embodiment of the present invention, the fixing ring is fixed by engaging with the connecting block through an elastic clip. The elastic clip design reduces the need for traditional screws, making the installation and removal of the fixing ring more efficient. At the same time, due to the design of the limit clamping column, the fixing ring is retained in a predetermined position by the limit clamping column, so that the fixing ring can be quickly positioned during assembly. The position of the elastic clip and the connecting block can be determined by simply aligning the limit notch with the limit clamping column, reducing manual adjustment and making installation faster and more accurate.

[0027] 4. The utility model is suitable for installing space-efficient monitoring devices, etc., reduces assembly restrictions, and has strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the overall structure of a thin aperture control structure applied to an imaging device according to Example 1 of the utility model;

[0029] Figure 2 This is a partial structural decomposition diagram of a thin aperture control structure applied to an imaging device according to Example 1 of the utility model;

[0030] Figure 3 for Figure 2 A magnified schematic diagram of the local structure at center A;

[0031] Figure 4 This is a schematic diagram of the overall structure of the thin aperture control structure applied to the imaging device in Example 1 of the utility model;

[0032] Figure 5 This is a schematic diagram of the overall structure of a fixing base of a thin aperture control structure applied to an imaging device according to embodiment 1 of the present utility model;

[0033] Figure 6 This is a schematic diagram of the overall structure of a thin aperture control structure applied to an imaging device according to embodiment 2 of the present utility model;

[0034] Figure 7 This is a schematic diagram of the structure decomposition of a thin aperture control structure applied to an imaging device according to Embodiment 2 of the present utility model;

[0035] Figure 8 This is a schematic diagram of the partial structural decomposition of a thin aperture control structure applied to an imaging device according to embodiment 2 of the present utility model.

[0036] In the picture:

[0037] 1. Fixing seat; 11. Rotating hole; 12. Limiting column; 13. Limiting hole; 14. First mounting slot; 15. Second mounting slot; 16. Arc groove; 17. Connecting block; 171. Guide slope; 18. Limiting block; 2. Blade assembly; 21. Blade; 211. Adjusting lever; 212. Limiting lever; 3. Turntable; 31. Strip hole; 32. Teeth; 33. Limiting groove; 34. Positioning piece; 4. Fixing ring; 41. Limiting notch; 411. Guide arc surface; 42. Elastic buckle; 421. Buckle groove; 43. Deformation notch; 5. Driving motor; 6. Transmission gear; 7. Sensing device; 8. First driven gear; 9. Second driven gear. DETAILED DESCRIPTION

[0038] To facilitate understanding of the present invention, a more comprehensive description of the present invention will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present invention.

[0039] In the description of the present invention, unless otherwise specified, the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. The term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. In addition, the "first" and "second" mentioned in the present invention do not represent specific quantities and orders, but are merely used to distinguish names.

[0040] Example 1

[0041] like Figure 1-5 As shown, this embodiment 1 provides a thin aperture control structure for an imaging device. This utility model is suitable for use in miniaturized imaging devices. The aperture control device comprises a fixing base 1 having a rotating hole 11 extending through the center thereof. The rotating hole primarily allows light to pass through it and enter the imaging device. By adjusting the size of the rotating hole (i.e., the diameter of the aperture), the amount of light entering the device can be controlled.

[0042] The upper surface of the fixing base 1 is stacked with a blade assembly 2, a rotating disk 3, and a fixing ring 4 for locking the blades 21 and the rotating disk 3. A through hole is provided in the middle of the fixing ring 4, which is connected to the rotating hole 11. The aperture of the through hole is larger than that of the rotating hole. The rotating disk is exposed in the through hole of the fixing ring, so that the lens of the imaging device can extend into the rotating disk through the through hole. This design can shorten the distance between the lens and the aperture blades, reduce the volume of the entire aperture control device, and make the imaging device design more compact and thin.

[0043] The blade assembly 2 is formed by a plurality of arcuate blades 21 arranged around the edge of the rotating hole 11; an integrally formed adjustment lever 211 is provided on the upper surface of one end of the blade 21, and a plurality of radially arranged strip holes 31 are provided on the rotating disk 3. The adjustment lever 211 is inserted into the strip holes 31 and reciprocates; an integrally formed limit lever 212 is provided on the lower surface of the other end of the blade 21, and a limit hole 13 is provided on the fixing base 1 to match the limit lever 212. The blade 21 is fixed to the fixing base 1 by the insertion of the limit lever 212 and the limit hole 13. The insertion design of the limit lever and the limit hole simplifies the installation process. Positioning is completed by simply aligning the blade with the limit hole on the fixing base and then inserting the limit lever into the limit hole. This reduces the multiple steps required in traditional assembly and avoids complex alignment and adjustment.

[0044] The outer edge of the turntable 3 is provided with a plurality of teeth 32, and the lower surface of the fixing base 1 is installed with a driving motor 5. After passing through the fixing base 1, the driving motor 5 engages with the teeth 32 of the turntable 3 through a transmission gear 6 for transmission. The turntable rotates under the drive of the driving motor, driving the adjustment lever of the blade to move along the strip hole. Since the fan-shaped arc blades are arranged around the rotating hole, the size of the aperture can be uniformly changed during the rotation or movement, so that the light can be transmitted to the sensor of the imaging device in the best way when passing through the aperture.

[0045] In order to make the turntable installation more stable, preferably, a first installation groove 14 for installing the blade group 2 and the turntable 3 is recessed under the fixing seat 1, and a second installation groove 15 for installing the transmission gear 6 is adjacent to one side of the first installation groove 14; the fixing ring is designed to cover the first installation groove.

[0046] In this embodiment, the transmission gear is meshed and connected with the teeth 32 of the turntable 3 through the first driven gear 8 and the second driven gear 9, thereby realizing multi-stage transmission.

[0047] In this embodiment, by improving the structural design of the turntable and the fixed ring, the turntable is directly exposed to the through hole of the fixed ring, so that the lens of the imaging device can enter the turntable through the through hole, greatly shortening the distance between the lens and the blade group. This not only makes the imaging device smaller, thinner and more compact, meeting the requirements of modern equipment for lightness and compactness; it also reduces optical errors, improves the clarity of image details, and more effectively achieves imaging effects.

[0048] The present invention also optimizes the structure of the blades, forming the blades, adjustment lever and limit column into one piece; on the one hand, the integration of the blades, adjustment lever and limit column can save the riveting process of the traditional aperture control structure, and the integration has better reliability, avoids the accumulation of tolerances between multiple parts, reduces the motion instability or error caused by assembly errors, and has higher precision; on the other hand, it is only necessary to install the one-piece blade assembly on the swivel and the base, wrap the blades around the mounting groove of the base, and then install the swivel, so that the overall structure of the shutter is more compact and the installation is faster.

[0049] Furthermore, the inner sidewalls of the first mounting slot 14 are provided with a plurality of limit blocks 18 extending radially toward the turntable 3. The outer periphery of the turntable 3 is provided with a limit groove 33 extending along its circumference. When the turntable 3 rotates within the first mounting slot 14, the limit blocks can move along the limit groove 33. The limit blocks extend radially within the first mounting slot and can precisely mate with the limit grooves on the turntable, preventing any wobble or offset during rotation and helping to limit the turntable's rotational travel, thus avoiding errors. They can also effectively reduce backlash during operation. This tight fit improves the stability of the turntable and reduces vibration and noise caused by backlash.

[0050] Preferably, an arc-shaped positioning piece 34 is provided on the outside of the turntable 3, extending toward the fixed base 1. The fixed base 1 is provided with an arc-shaped slot 16 for the reciprocating movement of the positioning piece 34. The length of the arc-shaped slot 16 is the same as the rotation stroke of the turntable 3. The arc-shaped slot 16 is provided with a sensing device 7 for sensing the positioning piece 34. In this embodiment, the length of the arc-shaped slot 16 is completely matched with the rotation stroke of the turntable 3. This ensures that the rotation range of the turntable is accurately limited to a predetermined range, so that the rotation stroke of the turntable does not exceed the set range, thereby preventing mechanical failure caused by exceeding the predetermined stroke.

[0051] Several limiting posts 12 are spaced apart along the outer edge of the fixing base 1. These posts 12 extend toward the fixing ring 4. The edge of the fixing ring 4 is provided with limiting notches 41 that match the limiting posts 12. The limiting posts 12 are positioned within these notches 41 to limit the horizontal displacement of the fixing ring 4. In this embodiment, the design of the limiting posts, combined with the limiting notches and the guiding slopes, ensures accurate positioning of the fixing ring. Since the limiting posts 12 do not protrude from the surface of the fixing ring 4, the fixing ring can easily contact the fixing base during installation without being hindered by the protruding posts.

[0052] Preferably, the height of the limiting post 12 is no greater than the thickness of the fixing ring 4, and the edge of the opening of the limiting notch 41 is provided with a guide arc 411 for guiding the limiting post 12 into the notch. In this embodiment, the presence of the guide arc further simplifies the installation process. By guiding the post into the notch, the complexity of alignment adjustment is reduced. The guide arc reduces friction between the fixing ring and the fixing seat, and helps the limiting post enter the notch smoothly, ensuring the correct positioning and alignment of the fixing ring.

[0053] Preferably, the outer periphery of the fixing seat 1 is provided with a plurality of connecting blocks 17 spaced apart along its circumference. The outer periphery of the fixing ring 4 is provided with a plurality of elastic clips 42 that are engaged with the connecting blocks 17. The elastic clips 42 are provided with clip grooves 421 that match the connecting blocks 17. The elastic clips 42 are engaged and fixed with the connecting blocks 17 through the clip grooves 421. The end of the connecting block 17 near the fixing ring 4 is provided with a guide slope 171 that is inclined toward the fixing seat 1. Furthermore, to increase the deformation capacity of the elastic clips, deformation notches 43 are provided on both sides of the elastic clips 42 to increase the deformation force of the elastic clips 42. In this embodiment, the elastic buckle 42 cooperates with the buckle groove 421 of the connecting block 17 to allow the fixing ring 4 to be quickly and stably fixed to the fixing base 1. The advantage of this design is that the elastic action of the elastic buckle ensures a secure engagement and simplifies the installation operation, allowing the user to easily install the fixing ring in place. The design of the guiding slope reduces alignment errors, ensuring a tight fit between the fixing ring 4 and the fixing base 1, thereby improving the stability and reliability of the entire device. The elastic buckle 42 is fixed to the connecting block 17 through the buckle groove 421, providing a secure and stable fixing effect. This locking structure effectively prevents the fixing ring 4 from loosening or displacement during use, ensuring the normal operation of the device.

[0054] It should be noted that the present invention also includes other components that meet the aperture control structure of the present invention, such as SMT circuit boards, FPC circuit boards, etc. Their working principles and installation structures can refer to the existing technology and will not be elaborated here.

[0055] Example 2

[0056] like Figure 6-8 As shown, the difference between Example 2 and Example 1 lies in the depth of the first mounting groove being greater than the depth of the second mounting groove. This allows the imaging device's lens to extend further into the through-hole of the fixing ring, further reducing the size of the imaging device. Furthermore, in Example 2, the limiting block can be positioned on the outer circumference of the turntable, while the limiting groove can be positioned within the inner circumference of the first mounting groove, similarly achieving the effect of the limiting block being movable along the limiting groove.

[0057] Furthermore, the transmission gear of the second embodiment is directly meshed with the teeth of the turntable.

[0058] In addition, this embodiment 2 can also add a waterproof film (not shown in the drawings) according to the needs of the application scenario, which is preferably set at the module of the drive motor and the circuit board, and its material and shape are not limited.

[0059] The present invention improves the structure of the aperture control device, achieving space optimization and an ultra-thin design for the control structure, while also making installation simpler and faster. Specifically, by improving the structural design of the turntable and the fixing ring, the turntable is directly exposed to the through-hole of the fixing ring, allowing the lens of the imaging device to enter the turntable through the through-hole, greatly shortening the distance between the lens and the blade group. This not only makes the imaging device smaller, thinner, and more compact, meeting the requirements of modern equipment for lightness, thinness, and compactness, but also reduces optical errors, improves the clarity of image details, and more effectively achieves imaging effects.

[0060] Furthermore, the shape of the turntable, the depth of the first mounting groove of the fixing seat, etc. can be designed according to the specific installation space or structural design requirements of the product to adapt to imaging devices with different lens lengths and more limited installation spaces, with strong adaptability.

[0061] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A thin aperture control structure for an imaging device, characterized in that: It comprises a fixing base with a rotating hole running through the middle; a blade assembly, a rotating disk and a fixing ring for locking the blades and the rotating disk are sequentially mounted on the upper surface of the fixing base; A through hole communicating with the rotating hole is provided in the middle of the fixing ring, the aperture of the through hole is larger than that of the rotating hole, and the rotating disk is exposed in the through hole of the fixing ring; The blade group is formed by a plurality of arc-shaped blades arranged around the edge of the rotating hole; an integrally formed adjustment lever is provided on the upper surface of one end of the blade, and a plurality of radially arranged strip holes are provided on the rotating disk, and the adjustment lever is passed through the strip holes and moves back and forth; an integrally formed limit lever is provided on the lower surface of the other end of the blade, and a limit hole matching the limit lever is provided on the fixing seat, and the blade is fixed on the fixing seat by inserting the limit lever into the limit hole; A plurality of teeth are provided on the outer edge of the turntable, and a driving motor is installed on the lower surface of the fixing seat. The driving motor passes through the fixing seat and is meshed with the teeth of the turntable through a transmission gear for transmission.

2. The thin aperture control structure for an imaging device according to claim 1, wherein: The fixing seat is concavely provided with a first mounting groove for mounting the blade assembly and the turntable, and a second mounting groove for mounting the transmission gear is adjacent to one side of the first mounting groove; the fixing ring is designed to cover the first mounting groove.

3. The thin aperture control structure for an imaging device according to claim 2, wherein: The depth of the first mounting groove is greater than the depth of the second mounting groove.

4. The thin aperture control structure for an imaging device according to claim 3, wherein: The inner side wall of the first installation groove is provided with a plurality of limit blocks extending radially toward the turntable, and the outer periphery of the turntable is provided with a limit groove extending along its circumference; when the turntable rotates in the first installation groove, the limit blocks can move along the limit groove.

5. The thin aperture control structure for an imaging device according to any one of claims 2 to 4, wherein: A plurality of limit posts are spaced apart on the outer peripheral edge of the fixing seat, and the limit posts extend toward the fixing ring. The edge of the fixing ring is provided with a limit notch matching the limit posts, and the limit posts are located in the limit notch to limit the horizontal displacement of the fixing ring.

6. The thin aperture control structure for an imaging device according to claim 5, wherein: The height of the limiting clamping column is not greater than the thickness of the fixing ring, and the opening edge of the limiting notch is provided with a guide arc surface for guiding the limiting clamping column to enter.

7. The thin aperture control structure for an imaging device according to claim 2, wherein: An arc-shaped positioning piece extending toward the fixing seat is provided on the outer side of the turntable, and the fixing seat is provided with an arc-shaped groove for the positioning piece to move back and forth; the length of the arc-shaped groove is the same as the rotation stroke of the turntable; and a sensing device for sensing the positioning piece is provided on the arc-shaped groove.

8. The thin aperture control structure for an imaging device according to any one of claims 2 to 4, wherein: The outer circumference of the fixing seat is provided with a plurality of connecting blocks spaced apart along its circumferential direction; the outer circumference of the fixing ring is provided with a plurality of elastic clips which are clamped and connected with the connecting blocks; the elastic clips are provided with buckle grooves which are adapted to the connecting blocks; the elastic clips are clamped and fixed with the connecting blocks through the buckle grooves; the end of the connecting block close to the fixing ring is provided with a guide inclined surface inclined toward the fixing seat.

9. The thin aperture control structure for an imaging device according to claim 8, wherein: Deformation notches are respectively provided on both sides of the elastic buckle to increase the deformation force of the elastic buckle.

10. The thin aperture control structure for an imaging device according to claim 9, wherein: The transmission gear is meshed with the teeth of the rotating disk through a first driven gear and a second driven gear.

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