CN113867095A - Projection equipment and method for lifting curtain - Google Patents

Abstract

The embodiment of the application discloses a projection device and a method for lifting a curtain, and belongs to the technical field of projection. The projection device includes: the projection screen comprises a base, a curling mechanism, a lifting mechanism and a screen sheet; the lifting mechanism comprises a first driving motor, a second driving motor, a first lifting frame, a second lifting frame, a cross beam, a plurality of detectors and a controller. In the embodiment of the application, rise at first driving motor and the first crane of second driving motor drive and second crane to when propping up the curtain through the crossbeam, a plurality of detectors detect the distance between base and the crossbeam respectively, and then through the comparison of the distance that the controller detected a plurality of detectors, with the second side of ensureing the curtain and being located same height, thereby can guarantee the planarization of curtain, avoid the curtain to take place the problem of distortion. Therefore, when the screen receives the light beam emitted by the optical engine and displays a picture, the problem of distortion of the displayed picture is avoided, and the projection effect of the projection equipment is improved.

Description

Projection equipment and method for lifting curtain

Technical Field

The embodiment of the application relates to the technical field of projection, in particular to a projection device and a method for lifting a curtain.

Background

With the continuous development of science and technology, projection equipment is more and more applied to the work and the life of people. The projection device mainly comprises an optical engine and a projection screen. The light outlet of the optical engine faces the projection device to emit a light beam to the projection screen, and the projection screen is used for reflecting the light beam to realize the display of the picture.

In the related art, a projection screen comprises a base, a curling mechanism, a lifting mechanism and a curtain sheet, wherein the lifting mechanism comprises a first lifting frame, a second lifting frame and a cross beam. The mechanism that curls is rotatable to be fixed on the base, and the first end of first crane and the first end of second crane all with the pedestal connection, the second end of first crane and the second end of second crane all are connected with the crossbeam, the first side and the mechanism fixed connection that curls of curtain piece, second side and crossbeam fixed connection relative with first side on the curtain piece. When the curtain sheet is not used, the first lifting frame and the second lifting frame are retracted, and the curtain sheet is curled through the curling mechanism; when using the curtain, prop the crossbeam through first crane and second crane to prop the curtain through the crossbeam, guarantee the roughness of curtain.

However, when the first crane and the second crane support the curtain, because the first crane and the second crane are worn and the like, the effective supporting height of the first crane is inconsistent with the effective supporting height of the second crane, so that the heights of the two ends of the cross beam are inconsistent, the phenomenon of the distortion of the curtain is easily caused, and the picture display effect of the curtain is further reduced.

Disclosure of Invention

The embodiment of the application provides a projection device and a method for lifting a screen, which can avoid the problem that the display picture is distorted due to inconsistent heights of two sides of the screen included by the projection device. The technical scheme is as follows:

in one aspect, a projection apparatus is provided, the projection apparatus comprising:

an optical engine to emit a light beam;

the projection screen comprises a base, a curling mechanism, a lifting mechanism and a curtain sheet;

the curling mechanism is limited on the base, the first side edge of the curtain sheet is fixedly connected with the curling mechanism, and the curling mechanism can rotate along the circumferential direction of the curling mechanism so as to control the curtain sheet to be folded;

the lifting mechanism comprises a first driving motor, a second driving motor, a first lifting frame, a second lifting frame, a cross beam, a plurality of detectors and a controller;

the first driving motor, the second driving motor and the detectors are fixed on the base, the first driving motor, the second driving motor and the detectors are all electrically connected with the controller, the first driving motor is connected with the first lifting frame, the second driving motor is connected with the second lifting frame, the first lifting frame and the second lifting frame are further connected with the cross beam, and a second side edge, opposite to the first side edge, of the screen sheet is fixedly connected with the cross beam;

the detector is used for detecting the base with distance between the crossbeam and transmit extremely the controller, the controller is used for being based on a plurality of distance control that the detector detected first driving motor with second driving motor is in order to drive first crane with the second crane rises, first crane with the second crane can prop the crossbeam is in horizontal position in order to expand the curtain piece, receive when the curtain piece expands the light beam.

Optionally, the detector is a laser detector or an infrared detector.

Optionally, an included angle formed by the light beam emitted by each detector and the vertical direction is an acute angle.

Optionally, the light beam emitted by each detector is parallel to the vertical direction.

Optionally, the number of the detectors is two, and a distance between the two detectors is greater than or equal to half of the length of the beam and less than or equal to the length of the beam.

Optionally, the first crane comprises a first connecting rod and a second connecting rod;

the first end of the first connecting rod is limited on the base and is in transmission connection with the first driving motor, the second end of the first connecting rod is in rotatable connection with the first end of the second connecting rod, the second end of the second connecting rod is in rotatable connection with the cross beam, and the first driving motor can drive the first connecting rod to rotate in a vertical plane.

In another aspect, a method for lifting a curtain is provided, where the method is applied to the projection apparatus of the above aspect, and the method includes:

the controller controls the first driving motor and the second driving motor to be started so as to control the first lifting frame and the second lifting frame to lift;

the controller acquires the distances between the base and the cross beam detected by the plurality of detectors;

controlling the first driving motor and the second driving motor to stop when the controller determines that the distances detected by the plurality of the probes are equal to a reference distance.

Optionally, the controlling the first driving motor and the second driving motor to stop when the controller determines that the distances detected by the plurality of detectors are equal to a reference distance includes:

controlling the first driving motor and the second driving motor to stop when the controller determines that the maximum distance among the distances detected by the plurality of probes is equal to the reference distance;

the controller determines a target driving motor to be started from the first driving motor and the second driving motor based on the minimum distance in the distances detected by the plurality of detectors, and controls the target driving motor to be started;

the controller acquires the distances detected by a plurality of the detectors again;

and when the controller determines that the reacquired distances detected by the plurality of detectors are all equal to the reference distance, controlling the target drive motor to stop.

Optionally, after the controller obtains the distances between the base and the beam detected by the plurality of detectors, the controller further includes:

the controller determines an angular velocity of the first drive motor based on any one of the distances detected by the plurality of detectors;

the controller controls the first drive motor to rotate based on the angular velocity.

Alternatively, when the first crane includes a first link and a second link, the controller determining the angular velocity of the first driving motor based on any one of the distances detected by the plurality of detectors includes:

based on the any distance, the reference transmission ratio, and the reference speed of the curtain deployment, the angular speed of the first drive motor is determined according to a first formula as follows:

the first formula:

wherein ω is an angular velocity of the first driving motor, L is the distance, V is a reference velocity of the curtain, and i is the reference transmission ratio.

The technical scheme provided by the embodiment of the application has the beneficial effects that at least:

rise at first driving motor and the first crane of second driving motor drive and second crane to when propping up the curtain through the crossbeam, detect the distance between base and the crossbeam respectively through a plurality of detectors, also be the height that detects the curtain and rise, and then the comparison of the distance that detects a plurality of detectors through the controller, be in horizontal position when guaranteeing the curtain to expand, also be that the second side of curtain is located same height, thereby can guarantee the planarization of curtain, avoid the curtain to take place the problem of distortion. Therefore, when the screen receives the light beam emitted by the optical engine and displays the picture, the problem of distortion of the displayed picture is avoided, the display effect of the screen is improved, and the projection effect of the projection equipment is improved.

Drawings

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

Fig. 1 is a schematic diagram illustrating a lifting mechanism according to an embodiment of the present disclosure;

FIG. 2 is a schematic structural diagram of a projection apparatus provided in an embodiment of the present application;

FIG. 3 is a schematic side view of a projection screen according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a lifting mechanism provided in an embodiment of the present application;

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

fig. 6 is a schematic flow structure diagram of a method for lifting a curtain according to an embodiment of the present application.

Reference numerals:

1: an optical engine; 2: a projection screen; 3: a storage section;

21: a base; 22: a crimping mechanism; 23: a lifting mechanism; 24: a screen sheet;

231: a first drive motor; 232: a second drive motor; 233: a first lifting frame; 234: a second lifting frame; 235: a cross beam; 236: a detector;

2331: a first link; 2332: a second link; 2333: a third link; 2334: a fourth link; 2335: a support bar; 2336: a slider; 2337: and a lead screw.

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.

Before the embodiments of the present application are described in detail, the desynchronization of the unfolding of the curtain and the raising of the display screen will be explained.

Referring to fig. 1, the first crane includes a first link 2331 and a second link 2332, and one end of the first link 2331 is connected to a first driving motor, so that when the first driving motor rotates at a constant speed, the first link 2331 is driven to rotate at a constant speed, that is, the angles a1, a2 and a3 of the rotation of the first link 2331 in the same time are equal. As can be seen from fig. 1, the rising heights b1, b2 and b3 of the end of the second link 2332 not connected to the first link 2331 are significantly different, that is, the rising speed of the end of the second link 2332 is significantly different when the first link 2331 rotates at a constant speed, so that the speed of the curtain is changed. The rising speed of the display picture projected by the optical engine is a fixed speed, so that the expansion of the curtain film and the rising of the display picture are asynchronous, and the picture display effect of the curtain film is reduced.

Fig. 2 illustrates a schematic structural diagram of a projection apparatus according to an embodiment of the present application, fig. 3 illustrates a schematic structural diagram of a projection screen in a side view, and fig. 4 illustrates a schematic structural diagram of a lifting mechanism according to an embodiment of the present application. With reference to fig. 2 and 3, the projection apparatus includes: an optical engine 1, the optical engine 1 being configured to emit a light beam; projection screen 2, projection screen 2 includes base 21, crimping mechanism 22, elevating system 23 and curtain 24. The winding mechanism 22 is limited on the base 21, the first side of the curtain sheet 24 is fixedly connected with the winding mechanism 22, and the winding mechanism 22 can rotate along the circumferential direction of itself to control the curtain sheet 24 to be folded.

As shown in fig. 4, the lifting mechanism 23 includes a first driving motor 231, a second driving motor 232, a first lifting frame 233, a second lifting frame 234, a cross beam 235, a plurality of detectors 236, and a controller (not shown); the first driving motor 231, the second driving motor 232 and the plurality of detectors 236 are fixed on the base 21, the first driving motor 231, the second driving motor 232 and the plurality of detectors 236 are all electrically connected with the controller, the first driving motor 231 is connected with the first lifting frame 233, the second driving motor 232 is connected with the second lifting frame 234, the first lifting frame 233 and the second lifting frame 234 are further connected with the cross beam 235, and a second side edge of the curtain sheet 24, which is opposite to the first side edge, is fixedly connected with the cross beam 235; the detectors 236 are used for detecting the distance between the base 21 and the cross beams 235 and transmitting the distance to the controller, the controller is used for controlling the first driving motor 231 and the second driving motor 232 to drive the first lifting frame 233 and the second lifting frame 234 to lift based on the distance detected by the plurality of detectors 236, the first lifting frame 233 and the second lifting frame 234 can lift the cross beams 235 to be in a horizontal position to unfold the curtain 24, and the curtain 24 receives light beams when unfolded.

In the embodiment of the present application, when the first driving motor 231 and the second driving motor 232 drive the first lifting frame 233 and the second lifting frame 234 to lift the curtain 24 by the cross beam 235, the distance between the base 21 and the cross beam 235 is detected by the plurality of detectors 236, that is, the height of the curtain 24 is detected, and further, the distance detected by the plurality of detectors 236 is compared by the controller, so as to ensure that the cross beam 235 is at the horizontal position when the curtain 24 is unfolded, that is, the second side of the curtain 24 is at the same height, thereby ensuring the smoothness of the curtain 24 and avoiding the problem of the curtain 24 being distorted. Thus, when the screen 24 receives the light beam emitted from the optical engine 1 and displays a picture, the problem of distortion of the displayed picture is avoided, and the display effect of the screen 24 is improved, thereby improving the projection effect of the projection device.

The controller is configured to determine that the cross beam 235 is at a horizontal position, and further configured to control the first driving motor 231 and the second driving motor 232 to ensure that the cross beam 235 ascends at a constant speed, so as to ensure synchronization between the spreading of the curtain sheet 24 and the rising of the display screen. The implementation manner of ensuring that the beam 235 ascends at a constant speed will be described in detail in the embodiment of the method corresponding to the projection apparatus.

Alternatively, the optical engine 1 is an ultra-short focus optical engine 1, so that the distance from the optical engine 1 to the plane of the projection screen 2 is set to be a short distance to achieve a compact design of the entire laser projection apparatus. The optical engine 1 includes a light source, an optical-mechanical system and a lens, the optical-mechanical system includes a DMD (Digital Micromirror array) board and a DMD, the light source is used for emitting a light beam to the optical-mechanical system, the DMD board included in the optical-mechanical system is used for providing a driving signal to the DMD, so that the DMD can modulate the light beam emitted from the light source based on the driving signal, emit the modulated light beam to the lens, and emit the light beam to the projection screen 2 through the lens for displaying.

Optionally, in this embodiment of the present application, the projection apparatus is a laser ultra-short focus projection apparatus, the ultra-short focus optical engine is a DLP (Digital Light processing) projection optical engine, and the optical engine 1 includes a lens that is an ultra-short focus projection lens. And, the screen 24 of the projection screen 2 is an optical film, such as a rollable fresnel optical screen, or may also be a flexible black screen, such an optical film has a higher optical gain compared to the conventional screen, can reduce the brightness and contrast of the light beam as much as possible, and can realize a higher flatness by the control and stretching of the control mechanism, and can be suitable for the application of ultra-short focus projection imaging.

Since the detector 236 is fixed on the base 21, and the distance between the detector 236 and the cross beam 235 is approximately the distance between the base 21 and the cross beam 235, the detector 236 can be used to directly detect the distance between the base 21 and the cross beam 235, and further determine whether the second side edges of the curtain 24 are at the same height according to the height of the cross beam 235.

It should be noted that the plurality of detectors 236 are located at the same height, that is, the fixing surface on which the plurality of detectors 236 are located is a horizontal surface. When the plurality of probes 236 are not located at the same height, the controller determines whether the cross beam 235 is located at a horizontal position based on the height difference of the plurality of probes 236 and the distance detected by each probe 236.

Optionally, the detector 236 is a laser detector 236 or an infrared detector 236. Of course, in other embodiments, the detector 236 is an ultrasonic detector 236 or other detectors 236 capable of detecting distance, and the like, which is not limited in the embodiments of the present application.

Wherein the detector 236 includes a transmitting portion and a receiving portion. Illustratively, when the detector 236 is a laser detector 236, the detector 236 includes a laser emitting portion and a laser receiving portion, the laser emitting portion is configured to emit laser light, and the laser receiving portion is configured to receive the reflected laser light; when the detector 236 is an infrared detector 236, the detector 236 includes an infrared emitting portion for emitting infrared light and an infrared receiving portion for receiving the reflected infrared light.

Optionally, the emitting portion and the receiving portion are independent, and an included angle formed between the light beam emitted from the emitting portion and the light beam reflecting surface (the beam 235) is an acute angle. Of course, in other embodiments, the emitting portion and the receiving portion are integrally designed, and the light beam emitted from the emitting portion is perpendicular to the light beam reflecting surface.

Optionally, the angle formed by the light beam emitted by each detector 236 and the vertical direction is equal. Thus, when the cross beam 235 is in the horizontal position, the distance between the emitting part of each detector 236 and the light beam reflecting surface is equal, that is, the length of the light beam between the emitting part and the cross beam 235 is equal, and the controller can directly compare the distances detected by the two detectors 236 after receiving the distance detected by each detector 236 to determine whether the cross beam 235 is in the horizontal position, without performing other conversions.

Illustratively, the included angle between the light beam emitted by each detector 236 and the vertical direction is an acute angle, that is, the included angle between the light beams emitted by two detectors 236 and the reflecting surface of the beam 235 is an acute angle; or the light beams emitted by each detector 236 are parallel to the vertical direction, that is, the light beams emitted by the two detectors 236 are perpendicular to the reflecting surface of the beam 235.

Of course, in some embodiments, the included angles formed by the light beams emitted by the plurality of detectors 236 and the vertical direction are not all equal, and at this time, for each detector 236, after the detector 236 detects the distance between the emitting portion and the beam 235, the controller calculates the vertical distance between the emitting portion and the beam 235 through the cosine theorem based on the distance and the included angle formed by the light beam and the vertical direction, and then compares the vertical distance corresponding to each detector 236 to determine whether the beam 235 is in the horizontal position.

Wherein a plurality of detectors 236 are arranged along the length of beam 235. In order to ensure the levelness of the beam 235, the number of the detectors 236 is two, and the distance between the two detectors 236 is greater than or equal to half of the length of the beam 235 and less than or equal to the length of the beam 235.

Illustratively, the plurality of probes 236 includes a first probe 236 and a second probe 236, a distance between the first probe 236 and the second probe 236 is equal to a length of the beam 235, the first probe 236 is configured to detect a first distance between a first end of the beam 235 and the base 21, and the second probe 236 is configured to detect a distance between a second end of the beam 235 and the base 21.

In some embodiments, as shown in fig. 4, the first crane 233 includes a first link 2331 and a second link 2332; the first end of the first link 2331 is limited on the base 21 and is in transmission connection with the first driving motor 231, the second end of the first link 2331 is rotatably connected with the first end of the second link 2332, the second end of the second link 2332 is rotatably connected with the cross beam 235, and the first driving motor 231 can drive the first link 2331 to rotate in the vertical plane.

Optionally, a pinion is fixed at a first end of the first link 2331, a main gear is fixedly connected to an output shaft of the first driving motor 231, the main gear is engaged with the pinion, and an axial direction of the output shaft of the first driving motor 231, an axial direction of the main gear, and an axial direction of the pinion are parallel to each other and are perpendicular to a length direction of the first link 2331. Thus, after the first driving motor 231 is started, the main gear is driven to rotate, and further the sub-gear is driven to rotate, and the first connecting rod 2331 is further driven to rotate by taking the central shaft of the sub-gear as a rotating shaft, so as to realize the lifting or lowering of the first lifting frame 233.

In other embodiments, as shown in fig. 5, the first crane 233 includes a third link 2333, a fourth link 2334, a support bar 2335, a slider 2336, and a lead screw 2337; a first end of the third link 2333 is rotatably connected to the base 21, a second end of the third link 2333 is rotatably connected to a first end of the fourth link 2334, and a second end of the fourth link 2334 is rotatably connected to the beam 235; the screw 2337 is fixedly connected to an output shaft of the first driving motor 231, the slider 2336 is engaged with the screw 2337, a first end of the support rod 2335 is rotatably connected to the slider 2336, a second end of the support rod 2335 is rotatably connected to the third link 2333, the first driving motor 231 can drive the screw 2337 to rotate along its circumferential direction, so as to drive the slider 2336 to slide in the length direction of the screw 2337, and the slider 2336 can drive the third link 2333 to rotate through the support rod 2335 when sliding.

Optionally, the length direction of the screw 2337 is parallel to the length direction of the cross beam 235, and one end of the screw 2337 is fixedly connected to the output shaft of the first driving motor 231. Thus, when the first driving motor 231 is turned on to drive the screw 2337 to rotate, the screw 2337 rotates in place, so that the slider 2336 moves in the length direction of the screw 2337 to support the support rod 2335 or retract the support rod 2335. When the slider 2336 slides to support the support rod 2335, the support rod 2335 drives the third link 2333 to rotate around the connection point of the third link 2333 and the base 21 as a rotation center, so as to realize the lifting of the first lifting frame 233, and further realize the lifting of the first lifting frame 233; when the slider 2336 slides to retract the support rod 2335, the support rod 2335 drives the third link 2333 to rotate around the connection point of the third link 2333 and the base 21 as a rotation center, so as to retract the first lifting frame 233, and further retract the first lifting frame 233.

In the embodiment of the present application, the second lifting frame 234 has the same structure as the first lifting frame 233 described in the first embodiment, or the same structure as the first lifting frame 233 described in the second embodiment, but the second lifting frame 234 may have another structure as long as it can be lifted by the driving of the second driving motor 232 and lift the cross beam 235, which is not limited in the embodiment of the present application.

In the embodiment of the present application, the optical engine 1 and the projection screen 2 included in the projection apparatus are provided in a split type, which facilitates the transportation of the optical engine 1 and the projection screen 2, and the separate maintenance in the later use process.

Of course, during normal use of the projection apparatus, the position between the optical engine 1 and the projection screen 2 is relatively fixed, and in this case, in order to avoid relative displacement between the optical engine 1 and the projection screen 2, as shown in fig. 1, the projection apparatus further includes a receiving portion 3, and the receiving portion 3 has a first receiving portion and a second receiving portion; the optical engine 1, the optical engine 1 is located in the cavity of the first containing part, the first containing part has a light-transmitting area, and the light beam emitted by the optical engine 1 can pass through the light-transmitting area; the projection screen 2, the projection screen 2 includes the base 21, curls the organization 22, the lifting gearing 23 and curtain slice 24; the base 21 and the curling mechanism 22 are located in the inner cavity of the second accommodating part, and the curling mechanism 22 can control the curtain sheet 24 to be retracted into the second accommodating part; the lifting mechanism 23 is disposed on the second accommodating portion, the second accommodating portion has an opening, the lifting mechanism 23 can control the curtain sheet 24 to pass through the opening for expansion, and the curtain sheet 24 can receive the light beam penetrating through the light-transmitting area after expansion.

Thus, the optical engine 1 is accommodated by the first accommodating portion, and the projection screen 2 is accommodated by the second accommodating portion, so that the optical engine 1 and the projection screen 2 are integrated, the situation that the optical engine 1 and the projection screen 2 are displaced relatively is avoided, and the picture display effect of the projection screen 2 is ensured.

The vertical distance from the center point of the transparent region to the plane of the developed screen 24 is equal to the product of the projection ratio of the optical engine 1 and the width of the display area on the screen 24, and the width of the display area refers to the size of the display area along the horizontal direction. Thus, the light beam emitted from the optical engine 1 can be projected to the display area of the screen 24 accurately, so as to ensure the clarity of the display picture on the screen 24.

Since the throw ratio is a performance parameter of the optical engine 1 itself, the throw ratio of the optical engine 1 is related to the selected optical engine 1 itself, that is, the throw ratio may be different for different optical engines 1, and further the vertical distance from the center point of the light-transmitting region to the plane where the unfolded screen 24 is located is different. In this way, in the actual installation process, the vertical distance from the center point of the light-transmitting area to the plane where the developed screen 24 is located is calculated by the projection ratio of the optical engine 1 and the width of the display area, and the vertical distance is determined as the vertical distance between the center point of the light-transmitting area and the center line of the opening in the length direction, so that the light beam emitted by the optical engine 1 can be completely projected on the display area of the screen 24.

Alternatively, the receiving portion 3 is a T-shaped structure, that is, the first receiving portion and the second receiving portion are connected to form a T-shaped structure, and the volume of the first receiving portion is smaller than that of the second receiving portion. This can reduce the space occupied by the storage unit 3, and particularly, the space occupied by the entire projection apparatus when the projection screen 2 is stored.

Optionally, the first accommodating portion and the second accommodating portion are detachably connected, or the first accommodating portion and the second accommodating portion are not detachably connected, that is, the first accommodating portion and the second accommodating portion are integrally connected.

In the embodiment of the application, rise at first crane of first driving motor and second driving motor drive and second crane, in order to prop up the curtain through the crossbeam, detect the distance between base and the crossbeam respectively through a plurality of detectors, also be the height that detects the curtain and rise, and then through the comparison of the distance that the controller detected a plurality of detectors, in order to ensure that the crossbeam is in horizontal position when the curtain expandes, also be the second side of curtain and be located same height, thereby can guarantee the planarization of curtain, avoid the curtain to take place the problem of distortion. Therefore, when the screen receives the light beam emitted by the optical engine and displays the picture, the problem of distortion of the displayed picture is avoided, the display effect of the screen is improved, and the projection effect of the projection equipment is improved.

Fig. 6 illustrates a schematic flow chart of a method for lifting a curtain according to an embodiment of the present application. The method is applied to the projection device described in the above embodiment, and as shown in fig. 6, the method includes the following steps.

Step 601: the controller controls the first driving motor and the second driving motor to start so as to control the first lifting frame and the second lifting frame to lift.

Wherein, the controller is a remote controller or a control panel. When the user uses the projection equipment, the user presses a corresponding key on the remote controller or a corresponding key on the control panel to control the power supply of the first driving motor and the second driving motor to be switched on, and after the first driving motor and the second driving motor are switched on, the first driving motor and the second driving motor are in a working state, namely the first driving motor and the second driving motor are started. The first lifting frame is controlled to lift after the first driving motor is started, and the second lifting frame is controlled to lift after the second driving motor is started.

The principle of controlling the first lifting frame and the second lifting frame to lift is described in the above embodiments, and the embodiments of the present application are not described herein again.

Step 602: the controller obtains the distances between the base and the beam detected by the plurality of detectors.

In the process that first crane and second crane rise, the crossbeam highly also can change, and a plurality of detectors can real-time detection base and the distance between the crossbeam this moment, perhaps the interval is preset for a long time and is detected the distance between base and the crossbeam to the distance transmission to the controller between base and the crossbeam that will detect.

After the controller obtains the distances detected by the plurality of detectors, the following steps 603 and 604 may be directly performed to determine the angular velocity of the first driving motor, or the steps 603 and 604 may be skipped to perform the step 605, which is not limited in this embodiment.

Step 603: the controller determines the angular velocity of the first drive motor based on any one of the distances detected by the plurality of detectors.

Optionally, when the first crane includes the first link and the second link, based on any one of the distance, the reference transmission ratio, and the reference speed of the curtain deployment, the angular speed of the first drive motor is determined according to a first formula as follows:

the first formula:

in the first formula, ω is an angular velocity of the first driving motor, L is any distance, V is a reference velocity of the curtain, and i is a reference transmission ratio.

Wherein, in connection with the description of the above embodiments, i refers to the ratio between the radius of the secondary gear and the radius of the primary gear.

Optionally, when the first crane includes a first connecting rod, a second connecting rod, a supporting rod, a slider and a lead screw, based on any distance, a reference speed of curtain expansion, a length of the supporting rod, a lead of the lead screw and a reference transmission ratio, determining an angular velocity of the first driving motor in combination with the following second formula, third formula and fourth formula:

the second formula:

the third formula: 4180.5b⁶-20563b⁵+41948b³+27518b²-8847.2b+1179.5

The fourth formula:

in the second, third and fourth formulas, b is an angular velocity of the first link, L is any distance, V is a reference velocity for spreading the curtain, a is an angular velocity of the support rod, ω is an angular velocity of the first driving motor, M is a length of the support rod, d is a lead of the lead screw, and i is a reference transmission ratio. In conjunction with the above example, i is 1.

It should be noted that, when the structure of the first crane is the same as that of the second crane, after the controller determines the angular velocity of the first driving motor in the above manner, the angular velocity of the first driving motor may be directly determined as the angular velocity of the second driving motor. When the structure of the first lifting frame is different from that of the second lifting frame, the controller determines the angular speed of the second driving motor according to the corresponding mode based on the structure of the second lifting frame.

Step 604: the controller controls the first drive motor to rotate based on the angular velocity.

The controller controls the rotation of the first drive motor based on the angular velocity of the first drive motor determined in step 603 above. The controller further controls the first drive motor to rotate based on the determined angular velocity of the second drive motor.

The controller can readjust the angular speed of the first driving motor and readjust the angular speed of the second driving motor, so that the first lifting frame and the second lifting frame are ensured to rise at a constant speed, and the synchronism of curtain sheet unfolding and display picture rising is realized.

Step 605: when the controller determines that the distances detected by the plurality of detectors are equal to the reference distance, the first driving motor and the second driving motor are controlled to stop.

In some embodiments, it can be determined that the distances detected by the plurality of probes are equal to the reference distance by the following steps 6051-6054, and the first driving motor and the second driving motor are controlled to stop.

6051: when the controller determines that the maximum distance among the distances detected by the plurality of detectors is equal to the reference distance, the first driving motor and the second driving motor are controlled to stop.

After the controller obtains the detected distances transmitted by the plurality of detectors, the detected distances of the plurality of detectors may be sorted to determine the maximum distance among the detected distances of the plurality of detectors. And then judging the relation between the maximum distance and the reference distance.

If the controller currently obtains that the maximum distance among the distances detected by the plurality of detectors is smaller than the reference distance, returning to the step 602 to obtain the distances detected by the plurality of detectors again until the controller determines that the maximum distance among the obtained distances detected by the plurality of detectors is equal to the reference distance, which indicates that one end of the cross beam is lifted to the height of the unfolded curtain sheet, and at the moment, the controller controls to disconnect the power supply of the first driving motor and the second driving motor so as to control the first driving motor and the second driving motor to stop.

6052: the controller determines a target driving motor to be started from the first driving motor and the second driving motor based on a minimum distance among the distances detected by the plurality of detectors, and controls the target driving motor to be started.

The minimum distance among the distances detected by the plurality of detectors is necessarily smaller than the reference distance, which indicates that the other end of the cross beam is not lifted to the height of the unfolded curtain sheet, and the cross beam is required to be continuously supported by the corresponding lifting frame. Accordingly, the controller may determine the target driving motor that needs to be started based on the minimum distance among the distances detected by the plurality of detectors.

If the end of the cross beam corresponding to the first lifting frame is lifted to the height of the curtain to be unfolded, the target driving motor is a second driving motor; and if one end of the cross beam corresponding to the second lifting frame is lifted to the height of the curtain to be unfolded, the target driving motor is the first driving motor. After determining the target driving motor, the controller controls the target driving motor to be restarted.

6053: the controller reacquires the distances detected by the plurality of detectors.

The manner of reacquiring the controller is the same as the manner of acquiring the controller described above, and details of this embodiment are not described herein.

6054: when the controller determines that the reacquired distances detected by the plurality of probes are equal to the reference distance, the control target driving motor is stopped.

When the controller determines that the distances detected by the plurality of reacquired detectors are equal to the reference distance, the controller indicates that the beam is entirely lifted to the height of the unfolded curtain, that is, the second side edge of the curtain is lifted to the reference distance, and the target driving motor is controlled to stop.

In the embodiment of the application, first crane and second crane are driven to rise by first driving motor and second driving motor to when the curtain is propped up through the crossbeam, detect the distance between base and the crossbeam respectively through a plurality of detectors, also be the height that detects the curtain and rise, and then through the comparison of the distance that the controller detected a plurality of detectors. When the controller determines that the distances detected by the detectors are equal to the reference distance, the first driving motor and the second driving motor are controlled to stop so as to ensure that the cross beam is in a horizontal position when the curtain is unfolded, namely, the second side edge of the curtain is at the same height, so that the smoothness of the curtain can be ensured, and the problem that the curtain is distorted is avoided. Therefore, when the screen receives the light beam emitted by the optical engine and displays the picture, the problem of distortion of the displayed picture is avoided, the display effect of the screen is improved, and the projection effect of the projection equipment is improved.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (10)

1. A projection device, characterized in that the projection device comprises:

an optical engine to emit a light beam;

the projection screen comprises a base, a curling mechanism, a lifting mechanism and a curtain sheet;

the curling mechanism is limited on the base, the first side edge of the curtain sheet is fixedly connected with the curling mechanism, and the curling mechanism can rotate along the circumferential direction of the curling mechanism so as to control the curtain sheet to be folded;

the lifting mechanism comprises a first driving motor, a second driving motor, a first lifting frame, a second lifting frame, a cross beam, a plurality of detectors and a controller;

the first driving motor, the second driving motor and the detectors are fixed on the base, the first driving motor, the second driving motor and the detectors are all electrically connected with the controller, the first driving motor is connected with the first lifting frame, the second driving motor is connected with the second lifting frame, the first lifting frame and the second lifting frame are further connected with the cross beam, and a second side edge, opposite to the first side edge, of the screen sheet is fixedly connected with the cross beam;

the detector is used for detecting the base with distance between the crossbeam and transmit extremely the controller, the controller is used for being based on a plurality of distance control that the detector detected first driving motor with second driving motor is in order to drive first crane with the second crane rises, first crane with the second crane can prop the crossbeam is in horizontal position in order to expand the curtain piece, receive when the curtain piece expands the light beam.

2. The projection device of claim 1, wherein the detector is a laser detector or an infrared detector.

3. The projection device of claim 2, wherein the light beam emitted by each of the detectors is at an acute angle to the vertical.

4. The projection device of claim 2, wherein the light beam emitted by each of the detectors is parallel to the vertical.

5. The projection device of any of claims 1-4, wherein the number of detectors is two, and a distance between two of the detectors is greater than or equal to half a length of the beam and less than or equal to the length of the beam.

6. The projection device of claim 1, wherein the first crane comprises a first link and a second link;

the first end of the first connecting rod is limited on the base and is in transmission connection with the first driving motor, the second end of the first connecting rod is in rotatable connection with the first end of the second connecting rod, the second end of the second connecting rod is in rotatable connection with the cross beam, and the first driving motor can drive the first connecting rod to rotate in a vertical plane.

7. A method for lifting a curtain, wherein the method is applied to the projection apparatus of any one of claims 1 to 6, the method comprising:

the controller controls the first driving motor and the second driving motor to be started so as to control the first lifting frame and the second lifting frame to lift;

the controller acquires the distances between the base and the cross beam detected by the plurality of detectors;

controlling the first driving motor and the second driving motor to stop when the controller determines that the distances detected by the plurality of the probes are equal to a reference distance.

8. The method of claim 7, wherein said controlling the first drive motor and the second drive motor to stop when the controller determines that the distances detected by the plurality of detectors are equal to a reference distance comprises:

controlling the first driving motor and the second driving motor to stop when the controller determines that the maximum distance among the distances detected by the plurality of probes is equal to the reference distance;

the controller determines a target driving motor to be started from the first driving motor and the second driving motor based on the minimum distance in the distances detected by the plurality of detectors, and controls the target driving motor to be started;

the controller acquires the distances detected by a plurality of the detectors again;

and when the controller determines that the reacquired distances detected by the plurality of detectors are all equal to the reference distance, controlling the target drive motor to stop.

9. The method of claim 7 or 8, wherein after the controller obtains the distances between the base and the beam detected by the plurality of detectors, further comprising:

the controller determines an angular velocity of the first drive motor based on any one of the distances detected by the plurality of detectors;

the controller controls the first drive motor to rotate based on the angular velocity.

10. The method of claim 9, wherein when the first crane includes a first link and a second link, the controller determining the angular velocity of the first drive motor based on any one of the distances detected by the plurality of detectors comprises:

based on the any distance, the reference transmission ratio, and the reference speed of the curtain deployment, the angular speed of the first drive motor is determined according to a first formula as follows:

the first formula:

wherein ω is an angular velocity of the first driving motor, L is the distance, V is a reference velocity of the curtain, and i is the reference transmission ratio.

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