TWI422951B - Aperture adjusting device - Google Patents

Description

Aperture adjustment device

The present invention relates to a diaphragm adjusting device, and more particularly to an aperture adjusting device having a gear ring.

Please refer to FIGS. 1 and 2, which are a conventional aperture adjustment device 9. The aperture adjusting device 9 includes a frame 91, a gear ring 92, a blade 93, a stepping motor 94, and a cover plate 95.

The gear ring 92 is slidably slidably mounted on the cover plate 95 by a plurality of hanging shafts 922 respectively on the plurality of sliding grooves 951 of the cover plate 95, and has a guide groove 921. The blade 93 is swingably coupled to the frame 91 and partially shields the aperture hole 911 of the frame 91. Further, the vane 93 has a stud 931 that projects into the guide groove 921 of the gear ring 92. The stepping motor 94 and the cover plate 95 are fixed to the frame 91, and the drive gear 941 of the stepping motor 94 meshes with the gear ring 92.

When the stepping motor 94 rotates, the drive gear 941 and the gear ring 92 can be rotated. When the gear ring 92 rotates, the boss 931 located in the guide groove 921 is pushed by the gear ring 92, thereby forcing the blade 93 to swing relative to the frame 91. As the swing angle of the blade 93 increases, the area of the aperture hole 911 blocked by the blade 93 also increases. The ratio of the area of the aperture hole 911 blocked by the blade 93 to the original area of the aperture hole 911 can be referred to as "shading rate".

Therefore, by controlling the amount of rotation (the number of rotation steps) of the stepping motor 94, the shielding rate of the aperture hole 911 can be controlled.

As can be seen from the above, the conventional aperture adjustment device 9 can smoothly achieve the purpose of aperture adjustment, but there are still some shortcomings, as explained below.

1. The swing range of the blade 93 is controlled by the length of the guide groove 921. When the guide groove 921 is longer, the swing range of the blade 93 is larger, and the shielding rate of the aperture hole 911 is also larger. However, the gear ring 92 is limited by the teeth necessary to provide the drive gear 941 for the stepping motor 94, and the other components such as the hanging shaft 922 for hanging the gear ring 92 on the cover plate 95, so that there is not enough area for the gear ring 92. Since the guide groove 921 is elongated, the shielding rate of the aperture hole 911 is difficult to increase.
2. In order to finely control the shielding rate, the variation of the change in the shielding rate is small, and it is necessary to reduce the increment of the rotation angle of the gear ring 92 caused by one step per step of the stepping motor 94. When the ratio of the rotational speed of the drive gear 941 to the gear ring 92 is larger, the smaller the increment of the rotational angle of the gear ring 92 caused by the stepping motor 94 per revolution, the smaller the swing angle increment of the blade 93, and thus the shielding rate. The increment of the change is small, which is beneficial to the fine control of the amount of light entering. However, reducing the number of teeth of the drive gear 941 to increase the rotational speed ratio has a limitation, so that the rotational speed ratio of the drive gear 941 to the gear ring 92 is not easily improved. In addition, if the angle of one step of the stepping motor 94 is reduced, the increment of the rotation angle of the gear ring 92 caused by one step per step of the stepping motor 94 is also limited by the specification of the stepping motor 94. Therefore, the change in the shielding rate of the aperture hole 911 of the conventional aperture adjustment device 9 is large, which is disadvantageous for the fine control of the amount of incoming light.
3. The gear ring 92 is attached to the cover plate 95, so the gear ring 92 requires a hanging shaft 922. However, the hanging shaft 922 is not easy to process, and the hanging shaft 922 requires high machining precision, so that the gear ring 92 can be smoothly rotated, so that mass production is not utilized. In addition, the friction between the hanging shaft 922 and the cover plate 95 is large, so that the torque for driving the gear ring 92 needs to be large.
4. Since the gear ring 92 needs to be provided with the hanging shaft 922 and the guide groove 921, the size of the gear ring 92 is large, and the weight of the gear ring 92 is also heavy, so that the torque of the drive gear ring 92 must be increased.

In view of the above, it is an urgent problem to be solved in the industry to provide an aperture adjusting device that can improve at least one of the above-mentioned deficiencies.

An object of the present invention is to provide an aperture adjusting device having a long guide groove to increase the swing range of the blade, thereby increasing the shielding rate of the aperture.

An aperture adjusting device according to an embodiment of the invention includes a bracket, a gear ring, at least one blade and a connecting member. The bracket includes an aperture hole and a first guiding groove, and has a first side and a second side opposite to the first side. The gear ring is rotatably disposed on the first side of the bracket, and the at least one blade is swingably disposed on the second side of the bracket for partially shielding the aperture. The connecting member is fixed to the gear ring and connected to the at least one blade through the first guiding groove. The gear ring is adapted to rotate the gear ring to move the connecting member along the first guiding groove to drive the at least one blade to swing.

Therefore, the bracket of one embodiment of the present invention can provide a larger area for the first guide groove to be extended, so that the rotation range of the gear ring and the swing range of the blade can be increased, thereby increasing the shielding rate of the aperture hole. In addition, the gear ring does not need to be provided with a guide groove, so the size and weight of the gear ring can be reduced, thereby reducing the torque required to drive the gear ring.

The above described objects, features and advantages will be more apparent from the following description.

Please refer to FIGS. 3 to 5 for a preferred embodiment of the aperture adjusting device 1 of the present invention. The aperture adjusting device 1 can be installed in a projector (not shown) to adjust the brightness of the light projected by the projector. The aperture adjusting device 1 includes a bracket 11 , a gear ring 12 , at least one blade 13 , a connecting member 14 and a driving module 15 .

Referring to the embodiment of Figures 5 and 6, the bracket 11 can be a disc structure and has a first side and a second side opposite the first side. In addition, the bracket 11 includes a diaphragm hole 111, a first guiding groove 112, an annular recess 113, an accommodating space 114, a rib 115 and a plurality of bumps 116.

The aperture hole 111 may be located at the center of the bracket 11, and the first guide groove 112 is located at the periphery of the aperture hole 111 and extends in the circumferential direction of the aperture hole 111. Both the aperture hole 111 and the first guide groove 112 penetrate the bracket 11 axially. The annular recess 113 is disposed on the first side of the bracket 11 and surrounds the aperture 111, and the first guide groove 112 is located in the annular recess 113. The accommodating space 114 is located at the periphery of the bracket 11 and penetrates the bracket 11 axially. In addition, the accommodating space 114 is further connected to the annular recess 113. The rib 115 may be an elongated structure and disposed on the second side of the bracket 11 and extending along the circumferential direction of the aperture hole 111. The bumps 116 may be a hemispherical or semi-cylindrical structure, and are disposed in the annular recess 113 and are equally spaced along the circumferential direction of the aperture hole 111.

The gear ring 12 can be generally circular in shape with a plurality of teeth 121 on its outer annular surface. The gear ring 12 is rotatably disposed on the first side of the bracket 11. The gear ring 12 rotates along an axis of rotation 122, and the axis of rotation 122 can pass through the axis of the aperture hole 111, so the gear ring 12 can actually rotate along the axis of the aperture hole 111. Further, the gear ring 12 is further disposed in the annular recess 113 to restrict the radial movement of the gear ring 12 relative to the aperture hole 111, as shown in FIG. The inner annular surface of the gear ring 12 is in contact with the bump 116 to form a point-to-face or line-to-surface contact, so that the contact area of the gear ring 12 with the bracket 11 is small, so when the gear ring 12 rotates relative to the bracket 11, Less friction.

It is to be noted that the material of the bracket 11 and the gear ring 12 is not particularly limited. In practical applications, the bracket 11 of the present invention may be plastic injection molded, and the material of the gear ring 12 may be metal (for example, copper). Preferably, the bracket 11 is made of a self-lubricating material, whereby the gear ring 12 can be smoothly rotated relative to the bracket 11 without the need for external lubrication.

At least one of the vanes 13 may have a substantially meniscus structure to partially shield the aperture opening 111. In one embodiment, the blade 13 includes a first blade 13A and a second blade 13B that are stacked one upon another. Among them, the first blade 13A is in contact with the rib 115 to reduce the contact area with the bracket 11, thereby reducing friction and being easy to swing. The distance from the second guide groove 132 of the first blade 13A to the rotating shaft 131 is shorter than that of the second blade 13B, and the rotating shaft 131 of the first blade 13A is closer to the rotating shaft 131 of the second blade 13B, and is closer to the rotating axis of the gear ring 12. 122. Each of the blades 13A, 13B has a rotating shaft 131 and a second guiding groove 132. The second guiding groove 132 extends in an extending direction, and the extending direction can pass through the rotating shaft 131 of the blade 13 .

Referring to the embodiment of FIGS. 7 and 8 , the first blade 13A and the second blade 13B are swingably disposed on the second side of the bracket 11 , and the rotating shaft 131 and the second guiding groove 132 are respectively located at the aperture. The radial sides of the holes 111 are both sides. The first blade 13A and the second blade 13B are respectively swung relative to the bracket 11 along the rotating shaft 131, and the extending direction of the second guiding groove 132 passes through the rotation axis 122 of the gear ring 12 (or the axis of the aperture hole 111). It is avoided that the connecting member 14 interferes when the first blade 13A and the second blade 13B are driven. Further, the second guide groove 132 partially overlaps the first guide groove 112 by the axial direction of the aperture hole 111; and as the swing angle of the first blade 13A and the second blade 13B changes, the aperture hole 111 is shielded The area (shadowing rate) will change.

The blade 13 (the first blade 13A and the second blade 13B) may be made of metal (for example, copper), because the bracket 11 is preferably made of a self-lubricating material, so that it is smooth without any additional lubrication. The ground rotates relative to the bracket 11.

The connector 14 can be a cylinder and is fixed to the gear ring 12 for rotation with the gear ring 12. The connector 14 passes through the first guide groove 112, and as the gear ring 12 rotates, the connector 14 moves along the first guide groove 112. As shown in Figures 7 and 8, when the connector 14 is moved to the end of the first guide groove 112, the gear ring 12 will not continue to rotate. It can be seen that the length of the first guide groove 112 can limit the range of rotation of the gear ring 12. The length of the first guide groove 112 (the distance between the two ends) is larger, and the range of rotation of the gear ring 12 is larger. In the present invention, the first guiding groove 112 is disposed on the bracket 11 so that the first guiding groove 112 has sufficient space to extend to increase the rotation range of the gear ring 12. In one embodiment, the range of rotation of the gear ring 12 is substantially 100 degrees.

After the connecting member 14 passes through the first guiding groove 112, it is further connected to at least one blade 13 (the first blade 13A and the second blade 13B). Thus, when the connecting member 14 moves along the first guiding groove 112, the first blade 13A and the second blade 13B can be swung. In detail, the connecting member 14 is connected to the first vane 13A and the second vane 13B through the second guide groove 132 of the first vane 13A and the second guide groove 132 of the second vane 13B. The connecting member 14 is simultaneously movable in the second guide groove 132 of the first blade 13A and the second blade 13B, and forces the first blade 13A and the second blade 13B to swing.

As shown in FIGS. 7 and 8, since the distance between the connecting member 14 to the rotating shaft 131 of the first blade 13A and the rotating shaft 131 of the second blade 13B is different, the range of rotation (oscillation) of the first blade 13A and the second blade 13B is also It will be different. In one embodiment, when the range of rotation of the gear ring 12 is about 100 degrees, the range of rotation of the first vane 13A is substantially 52 degrees, and the range of rotation of the second vane 13B is substantially 40.5 degrees. Since the swing range and size of the first blade 13A and the second blade 13B are different, when the first blade 13A and the second blade 13B are swung, different portions of the aperture hole 111 can be shielded, thereby increasing the shielding rate of the aperture hole 111. In an embodiment, the aperture ratio of the aperture aperture 111 can be up to 80%.

As apparent from the above, when the number of the blades 13 is increased, the shielding rate of the diaphragm holes 111 can be improved. Therefore, if the shielding rate of the aperture hole 111 needs to be increased, a third blade (not shown) may be stacked on the second blade 13B; or if the shielding rate of the aperture hole 111 needs to be reduced, the second blade 13B may be removed. Only the first blade 13A is retained.

The drive module 15 can generate a rotational motion, and the amount of rotational motion can be controlled. The drive module 15 is coupled to the gear ring 12 to drive the gear ring 12 to rotate to move the connecting member 14 along the first guide groove 112 to drive the blades 13 (the first blade 13A and the second blade 13B) to swing. The driving module 15 can control the rotation angle of the gear ring 12 to control the swing angle of the blade 13, thereby adjusting the shielding rate of the aperture hole 111.

In an embodiment, the driving module 15 can include a motor 151, a driving gear 152, and a double gear 153. The motor 151 can be a motor that can control the angle of rotation of the motor shaft, such as a stepper motor or a servo motor. The drive gear 152 is fixed to the motor 151 to drive the motor 151 to rotate along the motor shaft. The drive gear 152 and the double-layer gear 153 are both located in the accommodating space 114 of the bracket 11. The double-layer gear 153 has a first stage (gear) 1531 and a second stage (gear) 1532. The number of teeth of the first stage 1531 is smaller than the number of teeth of the second stage 1532. The first stage 1531 extends into the annular recess 113 of the bracket 11 and engages the teeth 121 of the gear ring 12; the second stage 1532 engages the drive gear 152.

Thereby, the rotational kinetic energy of the motor 151 can be transmitted to the gear ring 12 through the drive gear 152 and the double-layer gear 153 to rotate the gear ring 12. Moreover, due to the relationship of the double gear 153, the rotational speed of the gear ring 12 and the drive gear 152 can be 1 to 11 in one embodiment. Therefore, in an embodiment, when the minimum rotation angle increment of the motor 151 is 20 degrees, the minimum rotation angle increment of the gear ring 12 is 1.82 degrees. By dividing the range of rotation of the gear ring 12 by 100 degrees by 1.82 degrees, it can be seen that the range of rotation of the gear ring 12 can be divided into about 55 segments, meaning that the swing range of the first blade 13A and the second blade 13B can also be divided into about 55 segments. In other words, the shielding rate of the aperture hole 111 can be adjusted by dividing into about 55 segments, and the variation of the shielding rate is small, which is advantageous for finely controlling the amount of light passing through the aperture hole 111.

It is worth mentioning that the number of teeth of the first stage 1531 and the second stage 1532 of the double-layer gear 153 can be adjusted to change the speed ratio of the gear ring 12 to the drive gear 152 to meet different requirements. Therefore, in order to increase the rotational speed ratio, the number of teeth of the drive gear 152 is too small, or the gear ring 12 is too small in size to be easy to manufacture.

The aperture adjusting device 1 further includes a cover 16 and a cover 17. The cover plate 16 is fixed on the first side of the bracket 11, and the gear ring 12 is located between the cover plate 16 and the bracket 11, and the gear ring 12 does not need to be hung on the cover plate 16 as in the conventional aperture adjustment device 9, but It is directly accommodated in the annular recess 113 of the self-lubricating bracket 11. The cover plate 16 limits the axial movement of the gear ring 12 to prevent the gear ring 12 from disengaging from the bracket 11.

The cover body 17 is fixed to the second side of the bracket 11, and the at least one blade 13, the drive gear 152 and the double-layer gear 153 are located between the cover body 17 and the bracket 11, and the motor 151 is fixed to the outer edge surface of the cover body 17. on. The cover 17 can limit the axial movement of the blade 13 to prevent the blade 13 from coming off the bracket 11.

The above is the description of the aperture adjusting device 1. The aperture adjusting device 1 has at least one of the following features:

1. There is no guide groove and hanging shaft on the gear ring 12, so the gear ring 12 is small in size and light in weight, so that the driving torque of the gear ring 12 is reduced. In addition, the gear ring 12 is easy to manufacture and manufacture, so the production cost is low.
2. The bracket 11 can provide a larger area for the first guide groove 112 to extend to increase the range of rotation of the gear ring 12 and the blade 13, thereby increasing the shielding rate of the aperture hole 111.
3. The bracket 11 can be made of plastic, and thus can be produced by injection molding or the like to reduce the production cost. In addition, the bracket 11 can be self-lubricating, and the gear ring 12 and the blade 13 can be easily rotated without external lubrication to reduce the driving torque.
4. The double-layer gear 153 can greatly increase the rotational speed ratio of the drive gear 152 to the gear ring 12 to increase the number of segments for adjusting the shielding rate of the aperture hole 111.
5. The first blade 13A and the second blade 13B (or more blades 13) respectively shield different portions of the aperture hole 111 to increase the shielding rate of the aperture hole 111.

The embodiments described above are only intended to illustrate the embodiments of the present invention, and to explain the technical features of the present invention, and are not intended to limit the scope of protection of the present invention. Any changes or equivalents that can be easily made by those skilled in the art are within the scope of the invention. The scope of the invention should be determined by the scope of the claims.

[this invention]

1‧‧‧ aperture adjustment device

11‧‧‧ bracket

111‧‧‧ aperture hole

112‧‧‧First guiding groove

113‧‧‧ annular depression

114‧‧‧ accommodating space

115‧‧‧ ribs

116‧‧‧Bumps

12‧‧‧Gear ring

121‧‧‧ teeth

122‧‧‧Rotation axis

13‧‧‧ leaves

13A‧‧‧First blade

13B‧‧‧Second blade

131‧‧‧ shaft

132‧‧‧Second guiding groove

14‧‧‧Connecting parts

15‧‧‧Drive Module

151‧‧‧Motor

152‧‧‧ drive gear

153‧‧‧ double gear

1531‧‧‧ first level

1532‧‧‧ second level

16‧‧‧ Cover

17‧‧‧ Cover

[知知]

9‧‧‧ aperture adjustment device

91‧‧‧ frame

911‧‧‧ aperture hole

92‧‧‧Gear ring

921‧‧‧Guide

922‧‧‧ hanging axis

93‧‧‧ leaves

931‧‧‧Bump

94‧‧‧Stepper motor

941‧‧‧ drive gear

95‧‧‧ cover

951‧‧‧ slip groove

Fig. 1 is a combination diagram of a conventional aperture adjustment device.

Fig. 2 is an exploded view of a conventional aperture adjustment device.

Figure 3 is a combination view of a preferred embodiment of the aperture adjusting device of the present invention.

Figure 4 is an exploded view of a preferred embodiment of the aperture adjusting device of the present invention.

Fig. 5 is another exploded view of the preferred embodiment of the aperture adjusting device of the present invention.

Figure 6 is a combination view of some of the components of the preferred embodiment of the aperture adjusting device of the present invention.

Fig. 7 is a schematic view showing the minimum aperture of the preferred embodiment of the aperture adjusting device of the present invention.

Figure 8 is a schematic view showing the largest aperture of the preferred embodiment of the aperture adjusting device of the present invention.

1‧‧‧ aperture adjustment device

11‧‧‧ bracket

111‧‧‧ aperture hole

112‧‧‧First guiding groove

113‧‧‧ annular depression

114‧‧‧ accommodating space

116‧‧‧Bumps

12‧‧‧Gear ring

121‧‧‧ teeth

122‧‧‧Rotation axis

13‧‧‧ leaves

13A‧‧‧First blade

13B‧‧‧Second blade

131‧‧‧ shaft

132‧‧‧Second guiding groove

14‧‧‧Connecting parts

15‧‧‧Drive Module

151‧‧‧Motor

152‧‧‧ drive gear

153‧‧‧ double gear

1531‧‧‧ first level

1532‧‧‧ second level

16‧‧‧ Cover

17‧‧‧ Cover

Claims (14)

An aperture adjustment device comprising:
a bracket includes an aperture hole and a first guide groove, and has a first side and a second side opposite to the first side;
a gear ring rotatably disposed on the first side of the bracket;
At least one blade rotatably disposed on the second side of the bracket for partially shielding the aperture hole; and a connecting member fixed to the gear ring and connected to the at least one blade through the first guiding groove;
The gear ring is adapted to rotate to move the connecting member along the first guiding groove to drive the at least one blade to swing. The aperture adjusting device of claim 1, wherein the at least one blade has a second guiding groove, the connecting member extends into the second guiding groove, is adapted to move in the second guiding groove, and forces the at least A blade swings. The aperture adjusting device of claim 2, wherein the at least one blade has a rotating shaft, and the at least one blade swings relative to the bracket along the rotating shaft. The aperture adjusting device of claim 3, wherein the gear ring rotates along an axis of rotation, the second guiding groove extends in an extending direction, and the extending direction passes through the rotating axis of the gear ring and the at least one blade The shaft. The aperture adjusting device of claim 4, wherein the at least one blade comprises a first blade and a second blade stacked on each other, the rotation axis of the first blade being closer to the rotation axis of the second blade The rotation axis of the gear ring, and the connecting member extends into the second guiding groove of the first blade and the second guiding groove of the second blade. The aperture adjustment device of claim 5, wherein the bracket includes a rib and the rib is in contact with the first blade. The aperture adjusting device of claim 5, wherein one of the gear rings has a rotation range of substantially 100 degrees, one of the first blades has a rotation range of substantially 52 degrees, and one of the second blades has a rotation range substantially It is 40.5 degrees. The aperture adjusting device of claim 1, wherein the aperture adjusting device further comprises a driving module, the driving module comprises a motor, a double-layer gear and a driving gear, wherein the driving gear is fixed to the motor, the double The layer gear has a first stage and a second stage, respectively meshing with the gear ring and the drive gear, and one of the first stages has a smaller number of teeth than one of the second stages. The aperture adjusting device of claim 8, wherein the bracket has an accommodating space, and the double-layer gear and the driving gear are located in the accommodating space. The aperture adjusting device of claim 8, wherein the gear ring has a rotational speed ratio of one to eleven to the driving gear. The aperture adjustment device of claim 1, wherein the bracket has an annular recess around the aperture of the aperture, the first guide groove is located in the annular recess, and the gear ring is disposed in the annular recess. The aperture adjustment device of claim 11, wherein the bracket comprises a plurality of bumps disposed in the annular recess, the bumps being in contact with the gear ring. The aperture adjustment device of claim 1, wherein the bracket is self-lubricating. The aperture adjusting device of claim 1, wherein the aperture adjusting device further comprises a cover plate and a cover fixed to the bracket, the at least one blade is located between the cover and the bracket, and the gear ring is located Between the cover plate and the bracket.