CN218158498U - Projection lens and projection equipment - Google Patents

Abstract

The application discloses projection lens and projection equipment belongs to projection technical field. The application provides a projection lens includes: lens cone, zoom lens group, drive assembly and transmission mechanism. Wherein the drive mechanism has a locking protection assembly that is capable of applying a pressing force to the drive gear. When the zoom lens group is not positioned at the limit position, the pressing force can enable the driving gear and the rotating shaft to synchronously rotate, and then the driving gear can drive the zoom lens group to move in the axial direction through the transmission mechanism. When the zoom lens group is in the extreme position, the pressing force can not enable the driving gear and the rotating shaft to synchronously rotate any more, the driving gear and the rotating shaft are changed into relative sliding, and the probability that the driving motor and the zoom lens group are damaged is low. Therefore, even if a limit switch is not integrated in the projection lens, the driving motor and the zoom lens group can be protected, and the volume of the projection lens is reduced, so that the projection equipment integrating the projection lens is small in volume and light in weight.

Description

Projection lens and projection equipment

Technical Field

The application relates to the technical field of projection, in particular to a projection lens and projection equipment.

Background

With the improvement of the scientific and technical level, the projection equipment is more and more widely applied and can be applied to various occasions such as meeting rooms, family living rooms, classrooms and the like. In order to meet the focal length requirements of the projection device in various use occasions, a variable-focus projection lens is generally arranged in the laser projection device.

Currently, a projection lens in a projection device may generally include: lens cone, actuating mechanism, zoom lens group and limit switch. The lens cone and the zoom lens group are coaxially arranged, and at least part of the zoom lens group is positioned in the lens cone and movably connected with the lens cone. The driving mechanism can be fixed on the lens cone and can drive the zoom lens group to move in the axial direction. The limit switch can be connected with the driving mechanism, and when the driving mechanism drives the zoom lens group to move to the limit position, the limit switch can control the driving motor in the driving mechanism to stop working so as to ensure that the zoom lens group and the driving motor cannot be damaged.

However, the volume of the projection lens is large due to the large space occupied by the limit switch, and therefore, the projection device integrated with the projection lens is large in volume and heavy in weight.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a projection lens and projection equipment, can solve prior art's projection equipment's volume great, and the great problem of weight, technical scheme is as follows:

in one aspect, a projection lens is provided that includes: the device comprises a lens cone, a zoom lens group, a driving mechanism and a transmission mechanism;

the lens cone and the zoom lens group are coaxially arranged, and at least part of the zoom lens group is positioned in the lens cone and is movably connected with the lens cone;

the driving mechanism is fixed on the lens barrel, and the driving mechanism includes: the locking protection device comprises a driving motor, a rotating shaft connected with the driving motor, a driving gear sleeved on the rotating shaft and a locking protection component;

the transmission mechanism is respectively connected with the driving gear and the zoom lens group;

wherein the locking protection assembly is configured to: and applying pressing force parallel to the axial direction of the rotating shaft to the driving gear, wherein the pressing force can enable the driving gear and the rotating shaft to synchronously rotate when the zoom lens group is not in the limit position, and enable the driving gear to slide relative to the rotating shaft when the zoom lens group is in the limit position.

In another aspect, a projection apparatus is provided, including: an optical machine illumination system and the projection lens.

The beneficial effects brought by the technical scheme provided by the embodiment of the application at least comprise:

the application provides a projection lens includes: lens cone, zoom lens group, drive assembly and transmission mechanism. Wherein the drive mechanism has a locking protection assembly which can apply a suitable amount of pressing force to the drive gear. When the zoom lens group is not in the limit position, the pressing force can enable the driving gear and the rotating shaft to synchronously rotate. Therefore, when the driving motor in the driving mechanism drives the rotating shaft to rotate, the rotating shaft can drive the driving gear to synchronously rotate, and then the driving gear can drive the zoom lens group to move in the axial direction through the transmission mechanism. When the zoom lens group is at the limit position, the zoom lens group can not continuously move along the same direction, the reaction force applied to the driving gear by the zoom lens group through the transmission mechanism is larger, the driving gear and the rotating shaft can not synchronously rotate any more through the pressing force applied to the driving gear by the locking protection component, and the two parts slide relatively. Therefore, when the driving motor in the driving mechanism drives the rotating shaft to rotate, the rotating shaft cannot drive the driving gear to rotate, namely the driving gear stops rotating. Therefore, after the driving mechanism drives the zoom lens group to move to the extreme position through the transmission mechanism, although the driving motor in the driving mechanism still can continue to work, the driving gear in the driving mechanism stops rotating, and the driving motor and the zoom lens group can be guaranteed to be low in probability of being damaged. Therefore, even if a limit switch is not integrated in the projection lens, the driving motor and the zoom lens group can be effectively protected, the volume of the projection lens is effectively reduced, and the projection equipment integrating the projection lens is small in volume and light in weight.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a projection lens provided in an embodiment of the present application;

FIG. 2 is an exploded view of the projection lens shown in FIG. 1;

FIG. 3 is a schematic structural diagram of a driving mechanism provided in an embodiment of the present application;

FIG. 4 is an exploded view of the drive assembly shown in FIG. 3;

FIG. 5 is a schematic structural diagram of another driving mechanism provided in the embodiments of the present application;

FIG. 6 is an exploded view of the drive assembly shown in FIG. 5;

FIG. 7 is a schematic diagram illustrating a positional relationship between a sliding pad and a position limiting member according to an embodiment of the present disclosure;

FIG. 8 is a plan view of a sliding gasket provided in accordance with an embodiment of the present application;

FIG. 9 is a schematic view of a gear mounting seat, a driving gear and a sliding gasket according to an embodiment of the present disclosure;

fig. 10 is a schematic structural diagram of another projection lens provided in an embodiment of the present application;

fig. 11 is a schematic diagram of a projection apparatus provided in an embodiment of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

Referring to fig. 1 and fig. 2, fig. 1 is a schematic structural diagram of a projection lens according to an embodiment of the present disclosure, and fig. 2 is an exploded view of the projection lens shown in fig. 1. The projection lens 000 may include: lens barrel 100, zoom lens group 200, driving mechanism 300 and transmission mechanism 400.

The lens barrel 100 and the zoom lens group 200 in the projection lens 000 may be coaxially disposed, and at least a portion of the zoom lens group 200 may be located in the lens barrel 100 and movably connected to the lens barrel 100. Thus, the zoom lens assembly 200 can move in the axial direction within the lens barrel 100, so that the focal length of the projection lens 000 can be adjusted.

The driving mechanism 300 in the projection lens 000 may be fixed to the lens barrel 100. For a better structure, please refer to fig. 3, fig. 3 is a schematic structural diagram of a driving mechanism according to an embodiment of the present application. The driving mechanism 300 in the projection lens 000 may include: the locking protection device comprises a driving motor 301, a rotating shaft 302 connected with the driving motor 301, and a driving gear 303 and a locking protection component 304 sleeved on the rotating shaft 302.

The transmission mechanism 400 in the projection lens 000 may be connected to the driving gear 303 and the zoom lens group 200 in the driving mechanism 300, respectively.

In the present application, the driving gear 303 of the driving mechanism 300 is movably connected with the rotating shaft 302. That is, after the driving gear 303 is sleeved on the rotating shaft 302, the driving gear 303 and the rotating shaft 302 are in clearance fit. That is, a certain gap exists between the driving gear 303 and the rotating shaft 302. Thus, the drive gear 303 can slide on the rotating shaft 302 in the axial direction of the rotating shaft 302.

At least a portion of the lock protection assembly 304 of the drive mechanism 300 is secured to the shaft 302. For this reason, when the driving motor 301 rotates the rotating shaft 302, the locking protection assembly 304 may rotate synchronously with the rotating shaft 302.

Also, the lock protection assembly 304 in the drive mechanism 300 may be configured to: a pressing force parallel to the axial direction of the rotating shaft 302 is applied to the drive gear 303. The pressing force enables the driving gear 303 to rotate synchronously with the rotating shaft 302 when the zoom lens assembly 200 is not in the limit position, and enables the driving gear 303 to slide relative to the rotating shaft 302 when the zoom lens assembly 200 is in the limit position.

It should be noted that, in the projection lens 000, a reflecting mirror is usually fixedly installed in the lens barrel 100, and the light emitted from the zoom lens group 200 can be directed to and reflected by the reflecting mirror. For this reason, the extreme positions of the zoom lens assembly 200 in the embodiment of the present application mean: the farthest position when the zoom lens group 200 is moved in the axial direction in the direction away from the mirror, or the closest position when the zoom lens group 200 is moved in the axial direction in the direction close to the mirror.

In this case, the lock protection assembly 304 in the driving mechanism 300 can apply a pressing force to the driving gear 303, and the pressing force is not too large or too small. Therefore, when the zoom lens assembly 200 is not in the limit position, the reaction force applied by the transmission mechanism 400 to the driving gear 303 is small, and the driving gear 303 can be rotated synchronously with the rotating shaft 302 by the pressing force applied by the locking protection assembly 304 to the driving gear 303. Thus, when the driving motor 301 in the driving mechanism 300 drives the rotating shaft 302 to rotate, the rotating shaft 302 can drive the driving gear 303 to rotate synchronously, so that the driving gear 303 can drive the zoom lens group 200 to move axially through the transmission mechanism 400.

When the zoom lens assembly 200 is at the limit position, the zoom lens assembly 200 does not continue to move in the same direction, the reaction force applied by the zoom lens assembly 200 to the driving gear 303 through the transmission mechanism 400 is large, and the driving gear 303 and the rotating shaft 302 cannot rotate synchronously any more by the pressing force applied by the locking protection assembly 304 to the driving gear 303, and the two components slide relatively. Thus, when the driving motor 301 in the driving mechanism 300 drives the rotating shaft 302 to rotate, the rotating shaft 302 cannot drive the driving gear 303 to rotate, that is, the driving gear 303 stops rotating.

Thus, after the driving mechanism 300 drives the zoom lens assembly 200 to move to the extreme position through the transmission mechanism 400, although the driving motor 301 in the driving mechanism 300 still continues to work, the driving gear 303 in the driving mechanism 300 stops rotating, so that the probability that the driving motor 301 and the zoom lens assembly 200 are damaged is ensured to be low. Therefore, even if a limit switch is not integrated in the projection lens 000, the driving motor 301 and the zoom lens group 200 can be effectively protected, the volume of the projection lens 000 is effectively reduced, and the projection device integrated with the projection lens 000 is small in volume and light in weight.

In summary, the present application provides a projection lens comprising: lens cone, zoom lens group, drive assembly and transmission mechanism. Wherein the drive mechanism has a locking protection assembly which can apply a suitable amount of pressing force to the drive gear. When the zoom lens group is not in the limit position, the pressing force can enable the driving gear and the rotating shaft to synchronously rotate. Therefore, when the driving motor in the driving mechanism drives the rotating shaft to rotate, the rotating shaft can drive the driving gear to synchronously rotate, and then the driving gear can drive the zoom lens group to move in the axial direction through the transmission mechanism. When the zoom lens group is at the limit position, the zoom lens group can not continuously move along the same direction, the reaction force applied to the driving gear by the zoom lens group through the transmission mechanism is larger, the driving gear and the rotating shaft can not synchronously rotate any more through the pressing force applied to the driving gear by the locking protection component, and the two parts slide relatively. Therefore, when the driving motor in the driving mechanism drives the rotating shaft to rotate, the rotating shaft cannot drive the driving gear to rotate, namely the driving gear stops rotating. Therefore, after the driving mechanism drives the zoom lens group to move to the extreme position through the transmission mechanism, although the driving motor in the driving mechanism still can continue to work, the driving gear in the driving mechanism stops rotating, and the driving motor and the zoom lens group can be guaranteed to be low in probability of being damaged. Therefore, even if a limit switch is not integrated in the projection lens, the driving motor and the zoom lens group can be effectively protected, the volume of the projection lens is effectively reduced, and the projection equipment integrating the projection lens is small in volume and light in weight.

In the embodiment of the present application, referring to fig. 4, fig. 4 is an exploded view of the driving assembly shown in fig. 3, and the locking protection assembly 304 in the driving mechanism 300 may include: an elastic element 304a sleeved on the rotating shaft 302, and a locking piece 304b connected with the end of the rotating shaft 302 far away from the driving motor 301. Wherein an elastic member 304a is located between the driving gear 303 and the locking member 304b, the elastic member 304a being used to apply a pressing force parallel to the axial direction of the rotating shaft 302 to the driving gear 303.

In the present application, after the locking member 304b is connected to the end of the rotating shaft 302 away from the driving motor 301, the locking member 304b may apply a pressing force parallel to the axial direction of the rotating shaft 302 to the elastic member 304a, so that the elastic member 304a can be compressed to store a repulsive force, and further, the end of the elastic member 304a away from the locking member 304b can apply the repulsive force to the driving gear 303, so as to ensure that the elastic member 304a can apply the pressing force to the driving gear 303.

Illustratively, the end of the rotating shaft 302 facing away from the driving motor 301 has an external thread, and the locking member 304b has an internal threaded hole for engaging with the external thread, for example, the locking member 304b may be a nut. The locking member 304b is screwed with the end of the rotating shaft 302 facing away from the driving motor 301. Thus, after the locking member 304b is screwed with the end of the rotating shaft 302, the locking member 304b can be moved on the rotating shaft 302 in a direction approaching the elastic member 304a by rotating around the rotating shaft 302 until the elastic member 304a is compressed, so that the compressed elastic member 304a can apply a pressing force to the driving gear 303.

It should be noted that, when the distance of the locking member 304b moving towards the direction approaching to the elastic element 304a is larger, the larger compression amount of the elastic element 304a will result in a larger pressing force applied by the elastic element 304a to the driving gear 303, which may cause the driving gear 303 to still rotate under the driving of the rotating shaft 302 when the lens module 200 is at the limit position, and further may cause an undesirable phenomenon of damaging the driving motor 301 and the lens module 200. When the distance of the locking member 304b moving in the direction approaching to the elastic element 304a is smaller, the amount of compression of the elastic element 304a is smaller, which results in a smaller pressing force applied by the elastic element 304a to the driving gear 303, and may result in that the driving gear 303 still cannot rotate under the driving of the rotating shaft 302 when the zoom lens assembly 200 is not at the limit position, and thus the undesirable phenomenon that the zoom lens assembly 200 cannot be driven to move may occur.

For this reason, the pressing force applied to the drive gear 303 by the elastic member 304a in the present application cannot be too large or too small. In one possible implementation, the magnitude of the pressing force applied by the elastic element 304a to the driving gear 303 is positively correlated with the magnitude of the compression amount by which the elastic element 304a is compressed. Therefore, the moving distance of the locking member 304b in the direction approaching the elastic member 304a can be controlled to ensure that the elastic member 304a is compressed to an appropriate degree by the locking member 304b, and thus it can be ensured that the pressing force of the elastic member 304a against the driving gear 303 is not too large or too small. Thus, it is ensured that the pressing force can make the driving gear 303 rotate synchronously with the rotating shaft 302 when the zoom lens assembly 200 is not in the limit position, and make the driving gear 303 slide relative to the rotating shaft 302 when the zoom lens assembly 200 is in the limit position.

In the present embodiment, the elastic element 304a has various structures, for example, the elastic element 304a may be a compression spring or an elastic disc spring. For this reason, the following two alternative implementations are schematically illustrated in the embodiments of the present application:

in a first alternative implementation, as shown in fig. 3 and 4, when the elastic element 304a is an elastic disc spring, after the locking member 304b in the locking protection assembly 304 applies a pressing force to the elastic disc spring, the elastic disc spring can be compressed in the thickness direction, so that the compressed elastic disc spring can apply a pressing force to the driving gear 303.

In the present application, the locking protection assembly 304 may further include: an auxiliary washer 304f is sleeved on the rotating shaft 302, and the auxiliary washer 304f is located between the elastic disc spring and the locking member 304b. In this case, after the locking member 304b is fixed to the rotating shaft 302, the locking member 304b may apply a pressing force parallel to the axial direction of the rotating shaft 302 to the auxiliary washer 304f, so that the auxiliary washer 304f may uniformly transmit the pressing force to the elastic disc spring to ensure uniform compression of the elastic disc spring. Thus, the uniformly compressed elastic disc spring can apply a uniform pressing force to the driving gear 303.

It should be noted that, when the elastic element 304a is an elastic disc spring, since the thickness of the elastic disc spring is smaller, the length of the locking protection component 304 in the direction parallel to the rotating shaft 302 can be effectively reduced, and the tightness of the fit of each component in the locking protection component 304 can be improved, so as to effectively reduce the overall volume of the driving mechanism 300, and further reduce the overall volume of the projection lens 000.

Referring to fig. 5 and 6, fig. 5 is a schematic structural diagram of another driving mechanism provided in an embodiment of the present application, and fig. 6 is an exploded view of the driving assembly shown in fig. 5. When the elastic member 304a is a compression spring, the compression spring can be compressed in the longitudinal direction after the locking member 304b in the locking protection assembly 304 applies a pressing force to the compression spring, and thus it can be ensured that the compressed compression spring can apply a pressing force to the driving gear 303.

It should be noted that, in order to ensure that the locking member 304b can uniformly apply the pressing force to the elastic member 304a and that the elastic member 304a can apply the pressing force to the driving gear 303, both ends of the compression spring are processed so that the shape of the end portion of the compression spring contacting the locking member 304b is matched and the shape of the portion of the compression spring contacting the driving gear 303 is matched.

In the embodiment of the present application, as shown in fig. 4 and 6, the locking protection assembly 304 in the driving mechanism 300 may further include: a stop member 304c and a sliding pad 304d. To clearly see the positional relationship between the position-limiting member 304c and the sliding pad 304d in the locking protection assembly 304, please refer to fig. 7, and fig. 7 is a schematic diagram illustrating the positional relationship between the sliding pad and the position-limiting member according to an embodiment of the present disclosure. The limiting member 304c of the locking protection assembly 304 can be sleeved on the rotating shaft 302 and fixedly connected with the rotating shaft 302. Thus, when the driving motor 301 in the driving mechanism 300 drives the rotating shaft 302 to rotate, the rotating shaft 302 can drive the limiting member 304c to rotate synchronously.

The sliding washer 304d of the locking protection assembly 304 can be sleeved on the stopper 304c, and the sliding washer 304d is located between the driving gear 303 and the elastic element 304 a. The sliding pad 304d can slide on the limiting member 304c along the axial direction of the rotating shaft 302, and the sliding pad 304d can also rotate synchronously with the limiting member 304 c. Thus, the resilient member 304a of the lock protection assembly 304 can ensure that the sliding pad 304d can be tightly attached to the driving gear 303 after applying the pressing force to the sliding pad 304d, and the pressing force can be transmitted to the driving gear 303 through the sliding pad 304d. Thus, the pressing force from the elastic element 304a can act on the driving gear 303 more uniformly, so as to ensure that the rotating shaft 302 can better drive the driving gear 303 to rotate when the zoom lens assembly 200 is not in the limit position; when the zoom lens assembly 200 is at the limit position, the rotating shaft 302 and the driving gear 303 can better slide relatively.

In the present application, as shown in fig. 7, the sliding washer 304d has a through hole O, the shape of the through hole O matches the shape of the cross section of the limiting member 304c, and the shape of the through hole O and the shape of the cross section of the limiting member 304c are all arbitrary shapes other than a circle. For example, as shown in fig. 8, fig. 8 is a plan view of a sliding gasket provided in an embodiment of the present application, and the through hole O of the sliding gasket 304d may be a kidney-shaped hole. Here, the cross section of the stopper 304c means: a plane perpendicular to the length direction of the rotating shaft 302.

In this case, after the sliding gasket 304d is sleeved on the limiting member 304c through the through hole O, the sliding gasket 304d and the limiting member 304c are in clearance fit, so that the sliding gasket 304d can slide on the limiting member 304c along a direction parallel to the rotating shaft 301. Moreover, when the shape of the through hole O and the cross-sectional shape of the limiting member 304c are any shapes other than circular, after the rotating shaft 302 drives the limiting member 304c to rotate, the limiting member 304c can drive the sliding spacer 304d to rotate synchronously, so as to ensure that the driving gear 303 can rotate synchronously with the rotating shaft 301 when the zoom lens assembly 200 is not at the limit position.

In the embodiment of the present application, as shown in fig. 4 and 6, the locking protection assembly 304 may further include: the gear mounting base 304e is sleeved on the rotating shaft 302 and fixedly connected with the rotating shaft 302, the driving gear 303 is sleeved on the gear mounting base 304e and movably connected with the gear mounting base 304e, and the gear mounting base 304e is closer to the driving motor 301 relative to the limiting piece 304 c. In this way, the driving gear 303 can be stably sleeved on the rotating shaft 302 through the gear mounting seat 304 e.

For example, please refer to fig. 9, fig. 9 is a schematic diagram of a positional relationship between a gear mounting seat, a driving gear and a sliding gasket according to an embodiment of the present application. The gear mount 304e may include: mount pad body 304e1 to and with mount pad body 304e1 fixed connection's spacing baffle 304e2, spacing baffle 304e2 is closer to driving motor 301 for mount pad body 304e1, drive gear 303 cup joints on mount pad body 304e1, and one side and the contact of spacing baffle 304e2 of drive gear 303, the opposite side and the contact of sliding gasket 304d. Thus, after the sliding gasket 304d applies pressing force to the driving gear 303, the driving gear 303 and the limit baffle 304e2 can be ensured to be tightly attached together. Here, since the gear mounting seat 304e is fixedly connected to the rotating shaft 302, when the driving motor 301 drives the rotating shaft 302 to rotate, the rotating shaft 302 can drive the gear mounting seat 304e to rotate synchronously.

The drive gear 303 has a mounting hole K, and the shape of the mounting hole K and the shape of the cross section of the mount base body 304e1 are both circular. Thus, the driving gear 303 can be fitted to the mount body 304e1 through the mounting hole K. And after the driving gear 303 can be sleeved on the mounting seat body 304e1 through the mounting hole K, the driving gear 303 and the mounting seat body 304e1 are in clearance fit. In this way, after the elastic element 304a in the locking protection assembly 304 applies a pressing force to the driving gear 303 through the sliding spacer 304d, the driving gear 303 between the sliding spacer 304d and the limiting baffle 304e2 can be clamped by the mutual fit between the sliding spacer 304d and the limiting baffle 304e2, so that the driving gear 303 can rotate synchronously with the rotating shaft 302 without the zoom lens group 200 being in the extreme position. Moreover, in the case of the zoom lens assembly 200 in the extreme position, although the driving gear 303 between the sliding spacer 304d and the limiting stopper 304e2 is still in close contact with the two, the pressing force from the elastic element 304a is not enough to press the driving gear 303 any more, so that the driving gear 303 can slide relative to the rotating shaft 302.

It should be noted that, when the driving motor 301 in the driving mechanism 300 is operated, the driving motor 301 may drive the rotating shaft 302 to rotate. When the zoom lens assembly 200 is not in the limit position, the gear mounting base 304e, the driving gear 303, the limiting member 304c, the sliding spacer 304d, the elastic element 304a and the locking member 304b sleeved on the rotating shaft 302 can rotate synchronously with the rotating shaft. When the zoom lens assembly 200 is at the limit position, the gear mounting base 304e, the limiting member 304c, the sliding spacer 304d, the elastic element 304a and the locking member 304b sleeved on the rotating shaft 302 can still rotate synchronously with the rotating shaft, but the driving gear 303 sleeved on the rotating shaft 302 stops rotating.

In the embodiment of the present application, since at least a portion of the locking protection assembly 304 in the driving mechanism 300 is fixedly connected to the rotating shaft 302, the rotating shaft 302 and the locking protection assembly 304 are always rotated synchronously. Since the locking protection assembly 304 can apply a pressing force to the driving gear 303, when the driving mechanism 300 provides a driving force to the rotating shaft 302 to rotate the rotating shaft 302, a friction force may be generated between the driving gear 303 and the sliding pad 304d of the locking protection assembly 304, and a friction force may also be generated between the driving gear 303 and the limit stop 304e2 of the locking protection assembly 304. Here, the frictional force received by the drive gear 303 has two expressions.

The first expression of friction force: when the zoom lens assembly 200 is not in the extreme position, the rotating shaft 302, the driving gear 303 and the locking protection assembly 304 all rotate synchronously, and the three components are in a relatively static state, and the friction force applied to the driving gear 303 is a static friction force.

The second expression of friction: when the zoom lens assembly 200 is at the extreme position, the rotating shaft 302 and the driving gear 303 slide relative to each other, and the friction force applied to the driving gear 303 is a kinetic friction force.

In this case, when the zoom lens assembly 200 is not in the extreme position, the force exerted by the driving assembly 303 satisfies the following relationship:

wherein, T1 is a torque required to be provided for the driving mechanism 300 to drive the transmission mechanism 400 to rotate; k1 is the total transmission efficiency of the torque output by the drive mechanism 300; k2 is a ratio of an angular velocity of the drive gear 303 in the rotational state to an angular velocity of the transmission mechanism 400 in the rotational state; t2 is the torque value output by the driving mechanism 300; m1 is the dynamic friction torque between the drive gear 303 and the locking protection assembly 304; t3 is the static friction torque between the drive gear 303 and the lock protection assembly 304.

In this way, it is ensured that the driving gear 303 and the rotating shaft 302 rotate synchronously, so that the driving gear 303 can drive the zoom lens group 200 to move through the transmission mechanism 400.

When the zoom lens assembly 200 is not in the extreme position, the force applied to the driving assembly 303 satisfies the following relationship:

in this way, relative sliding between the driving gear 303 and the rotating shaft 302 can be ensured, so that the driving gear 303 can stop rotating.

Optionally, as shown in fig. 10, fig. 10 is a schematic structural diagram of another projection lens provided in the embodiment of the present application. The transfer mechanism 400 in the projection lens 000 may include: a gear ring 401 and a transition gear 402. The gear ring 401 in the transmission mechanism 400 may be sleeved on the zoom lens assembly 200, and the gear ring 401 is in threaded connection with the zoom lens assembly 200. The transition gear 402 in the transmission mechanism 400 may mesh with the gear ring 401 and the drive gear 303, respectively. Here, the zoom lens group 200 is further generally provided with a limiting structure for limiting the gear ring 401, and the limiting structure can ensure that the gear ring 401 only rotates and does not move in the axial direction of the zoom lens group 200. Thus, when the driving electrode 301 drives the driving gear 303 to rotate through the rotating shaft 302, the driving gear 303 can drive the transition gear 402 to rotate, so that the transition gear 402 can drive the gear ring 401 to rotate, and further, the zoom lens group 200 can move in the axial direction through the threaded connection between the gear ring 401 and the zoom lens group 200.

In summary, the present application provides a projection lens comprising: lens cone, zoom lens group, drive assembly and transmission mechanism. The driving mechanism is provided with a locking protection component which can apply a pressing force with a proper magnitude to the driving gear. When the zoom lens group is not in the limit position, the pressing force can enable the driving gear and the rotating shaft to synchronously rotate. Therefore, when the driving motor in the driving mechanism drives the rotating shaft to rotate, the rotating shaft can drive the driving gear to synchronously rotate, and then the driving gear can drive the zoom lens group to move in the axial direction through the transmission mechanism. When the zoom lens group is in the extreme position, the zoom lens group can not move continuously along the same direction, the reaction force applied to the driving gear by the zoom lens group through the transmission mechanism is large, the driving gear and the rotating shaft can not rotate synchronously any more through the pressing force applied to the driving gear by the locking protection component, and the two components slide relatively. Therefore, when the driving motor in the driving mechanism drives the rotating shaft to rotate, the rotating shaft cannot drive the driving gear to rotate, namely the driving gear stops rotating. Therefore, after the driving mechanism drives the zoom lens group to move to the extreme position through the transmission mechanism, although the driving motor in the driving mechanism still can continue to work, the driving gear in the driving mechanism stops rotating, and the driving motor and the zoom lens group can be guaranteed to be low in probability of being damaged. Therefore, even if a limit switch is not integrated in the projection lens, the driving motor and the zoom lens group can be effectively protected, the volume of the projection lens is effectively reduced, and the projection equipment integrating the projection lens is small in volume and light in weight.

Referring to fig. 11, fig. 11 is a schematic view of a projection apparatus provided in an embodiment of the present application, where the projection apparatus 001 may include: an optical engine illumination system (not shown) and a projection lens (not shown). The optical machine illumination system is configured to modulate a laser beam provided by the light source into an image beam and emit the image beam to the projection lens, and the projection lens is configured to image the image beam and emit the image beam to the projection screen 002. Here, the projection lens may be the projection lens in the above-described embodiment. This projection lens may be, for example, the projection lens 000 shown in fig. 1, 2, or 10.

In this application, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "plurality" means two or more unless expressly limited otherwise.

The above description is intended to be exemplary only, and not to limit the present application, and any modifications, equivalents, improvements, etc. made within the spirit and scope of the present application are intended to be included therein.

Claims (10)

1. A projection lens, comprising: the device comprises a lens cone, a zoom lens group, a driving mechanism and a transmission mechanism;

the lens cone and the zoom lens group are coaxially arranged, and at least part of the zoom lens group is positioned in the lens cone and is movably connected with the lens cone;

the driving mechanism is fixed on the lens barrel, and the driving mechanism includes: the locking protection device comprises a driving motor, a rotating shaft connected with the driving motor, a driving gear sleeved on the rotating shaft and a locking protection component;

the transmission mechanism is respectively connected with the driving gear and the zoom lens group;

wherein the locking protection assembly is configured to: and applying pressing force parallel to the axial direction of the rotating shaft to the driving gear, wherein the pressing force can enable the driving gear and the rotating shaft to synchronously rotate when the zoom lens group is not in the limit position, and enable the driving gear to slide relative to the rotating shaft when the zoom lens group is in the limit position.

2. The projection lens of claim 1 wherein the locking protection assembly comprises: cup joint in the epaxial elastic element of pivot, and with the pivot deviates from driving motor's end connection's retaining member, elastic element is located drive gear with between the retaining member, elastic element be used for to drive gear applys the packing force.

3. The projection lens of claim 2 wherein the locking protection assembly further comprises: the limiting part is sleeved on the rotating shaft and fixedly connected with the rotating shaft, and the sliding gasket is sleeved on the limiting part and is positioned between the driving gear and the elastic element;

the sliding gasket can slide on the limiting part along the axial direction of the rotating shaft, and can also synchronously rotate with the limiting part.

4. The projection lens of claim 3, wherein the sliding pad has a through hole, the shape of the through hole matches with the shape of the cross section of the limiting member, and the shape of the through hole and the shape of the cross section of the limiting member are any shape except for a circle.

5. The projection lens of claim 3 wherein the locking protection assembly further comprises: the gear mounting seat is sleeved on the rotating shaft and fixedly connected with the rotating shaft, the driving gear is sleeved on the gear mounting seat and movably connected with the gear mounting seat, and the gear mounting seat is relatively close to the driving motor relative to the limiting part.

6. The projection lens of claim 5 wherein the gear mount comprises: the mounting seat body, and with mounting seat body fixed connection's limit baffle, limit baffle for the mounting seat body is closer to driving motor, drive gear cup joints on the mounting seat body, just one side of drive gear with limit baffle contact, the opposite side with sliding gasket contact.

7. The projection lens of any one of claims 2 to 6, wherein an end of the rotating shaft facing away from the driving motor has an external thread, the locking member has an internal thread hole matched with the external thread, and the locking member is in threaded connection with an end of the rotating shaft facing away from the driving motor.

8. The projection lens of claim 7 wherein the elastic element is an elastic disc spring or a compression spring.

9. The projection lens of claim 8 wherein when the elastic element is an elastic disc spring, the locking protection assembly further comprises: the auxiliary gasket is sleeved on the rotating shaft and located between the elastic disc spring and the locking piece.

10. A projection device, comprising: an optical engine illumination system and a projection lens according to any one of claims 1 to 9.

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