PROJECTION DEVICE AND CONTROL METHOD THEREOF

A projection device and a control method of the projection device are provided. The control method of the projection device includes following steps. Position information of the projection device is obtained by a sensor. A first moving signal is generated by at least one processor according to the position information. According to the first moving signal, a projection lens module is controlled by a driving member to move relative to the projection device.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of China application serial no. 202310234918.1, filed on Mar. 13, 2023. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

Technical Field

The invention relates to a projection technology and particularly relates to a projection device and a control method thereof.

Description of Related Art

An existing ultra short focal projection device is, in most cases, capable of projecting images of one single size. An user who intends to adjust a size of a projected image is required to move the entire projection device to change a distance between the projection device and a projection target (e.g., a screen or a wall). After the position of the projection device is set, if the projection device accidentally collides with something and is shifted, the user needs to move the entire projection device again to adjust the projected image. In another aspect, if the user intends to watch the projected image of a large size, the user is required to place the projection device at a position far away from the projection target. As such, a lot of available space may be wasted.

SUMMARY

The invention is directed to a projection device and a control method of the projection device capable of controlling a projection lens module to move relative to the projection device, so as to adjust a size of a projected image.

Other objectives and advantages of the invention may further be learned from technical features disclosed in the invention.

In order to achieve one or a portion of or all of the objects or other objects, an embodiment of the invention provides a projection device that includes an optical engine module, a projection lens module, a sensor, a driving member, and at least one processor. The optical engine module is configured to provide an image beam. The projection lens module is disposed on a transmission path of the image beam and configured to project the image beam out of the projection device. The sensor is configured to obtain position information of the projection device. The driving member is coupled to the projection lens module. The at least one processor is coupled to the sensor and the driving member. The at least one processor generates a first moving signal according to the position information and transmits the first moving signal to the driving member, and the driving member controls the projection lens module to move relative to the projection device according to the first moving signal.

In order to achieve one or part or all of the above objects or other objects, an embodiment of the invention provides a control method of a projection device, where the projection device includes a sensor, a driving member, at least one processor, and a projection lens module configured to project an image beam, and the control method includes following steps. Position information of the projection device is obtained by the sensor. A first moving signal is generated by the at least one processor according to the position information. According to the first moving signal, the projection lens module is controlled by the driving member to move relative to the projection device.

In view of the above, the projection device provided in one or more embodiments of the invention may control the projection lens module through the driving member to move relative to the projection device, so as to enlarge or reduce a projected image within the proper range of the projection size.

DESCRIPTION OF THE EMBODIMENTS

FIG.1is a schematic view illustrating a projection device10according to an embodiment of the invention. The projection device10may include a housing100, at least one processor110(FIG.1illustrates one processor as an example), a storage medium120, an input device130, a sensor140, a driving member150, an optical engine module160, and a projection lens module170. The at least one processor110, the storage medium120, the input device130, the sensor140, the driving member150, and the optical engine module160may be disposed in the housing100. The projection lens module170may be embedded in the housing100. The housing100of the projection device10may be fixed at a specific location (e.g., on a table or a ceiling).

The at least one processor110is, for instance, a central processing unit (CPU), any other programmable general purpose or special purpose micro control unit (MCU), microprocessor, digital signal processor (DSP), programmable controller, application specific integrated circuit (ASIC), graphics processing unit (GPU), image signal processor (ISP), image processing unit (IPU), arithmetic logic unit (ALU), complex programmable logic device (CPLD), field programmable gate array (FPGA), another similar element, or a combination of the above-mentioned elements. The number of the at least one processor110may be one or multiple. The at least one processor110is coupled (electrically connected) to the storage medium120, the input device130, the sensor140, the driving member150, the optical engine module160, and the projection lens module170, and the at least one processor110may access and execute a number of modules and various application programs stored in the storage medium120.

The storage medium120is, for instance, any type of fixed or movable random access memory (RAM), read only memory (ROM), flash memory, hard disk drive (HDD), solid state drive (SSD), or any other similar element, or a combination of the above-mentioned elements. The storage medium120is configured to store the modules or the application programs which may be executed by the at least one processor110.

The input device130is configured to receive a user command. The user may operate the projection device10through the input device130. The input device130may include keys, a button, a touch screen, or the like, for instance.

The sensor140is configured to measure position information of the projection device10, where the position information is, for instance, a distance between the projection device10and a projection target (e.g., a screen or a wall). The sensor140may be, for instance, a time of flight (ToF) sensor.

The driving member150is coupled (electrically connected) to the projection lens module170and may be configured to control the projection lens module170to move relative to the projection device10(the housing100). When the at least one processor110intends to control the projection lens module170to move, the at least one processor110may transmit a moving signal to the driving member150. The driving member150may control the projection lens module170to move relative to the projection device10(the housing100) according to the moving signal, where a moving distance of the projection lens module170is associated with the moving signal.

The driving member150includes, for instance, at least one of a motor, a belt, a rack, a screw, a steel wire and a gear. When the projection lens module170is controlled by the driving member150to move relative to the projection device10on a sliding rail, the projection lens module170may protrude from the housing100, as shown inFIG.1.FIG.2is a schematic view illustrating the projection lens module170moves relative to the projection device10(the housing100) according to an embodiment of the invention. When the projection lens module170moves relative to the projection device10and protrudes from the housing100, a projection size of an image30projected by the projection lens module170on the projection target (e.g., a screen or a wall) may be changed. For instance, the projection lens module170is a reflective ultra short focal projection lens, as shown on the right side ofFIG.2; the longer the moving distance of the projection lens module170, i.e., the longer the length of the projection lens module170protruding from the housing100is, the larger the projection size of the image30is. As shown on the left side ofFIG.2, the shorter the moving distance of the projection lens module170, e.g., the shorter the length of the projection lens module170protruding from the housing100is, the smaller the projection size of the image30is. That is, the projection device10provided in this embodiment may be placed at a fixed position and may project the image30of different projection sizes.

With reference toFIG.1, the optical engine module160is configured to provide an image beam. The optical engine module160may include a light source and a light valve. The light source is configured to provide an illumination beam. The light source may, for instance, include a light emitting diode (LED), a laser diode (LD), or a combination thereof. The light source may also be used together with a wavelength conversion element (phosphor wheel), a light homogenizing element (rod), a light filtering element (filter wheel), at least one light guiding element (mirror, beam splitter), or a combination thereof. The light valve is located on a transmission path of the illumination beam, and the light valve is configured to convert the illumination beam to the image beam. The light valve may include a digital micro-mirror device (DMD), a liquid crystal on silicon (LCOS) panel, a liquid crystal display (LCD), or any other spatial optical modulators.

The projection lens module170may be disposed on a transmission path of the image beam provided by the optical engine module160, and may be configured to project the image beam out of the projection device10. The projection lens module170is, for instance, an ultra short focal lens. The projection lens module170may include a combination of one or a plurality of optical lenses having a diopter, such as a biconcave lens, a biconvex lens, a concave-convex lens, a convex-concave lens, a plano-convex lens, a plano-concave lens, any other non-planar lens, or a combination thereof. In an embodiment, the projection lens module170may include a planar optical lens and may project the image beam from the optical engine module160out of the projection device10in a reflective or penetrating manner.

FIG.3AandFIG.3Bare flowcharts illustrating a control method of the projection device10according to an embodiment of the invention. After the projection device10is activated, in step S301, the at least one processor110may obtain the position information of the projection device10through the sensor140, where the position information is, for instance, the distance between the projection device10and the projection target.

In step S302, the at least one processor110may determine whether the storage medium120stores a mapping relationship between the position information and a specific moving signal. In the embodiment, the mapping relationship may be considered as a use record of the projection device10. The use record may include the last use record or all historical use records. If there exists a mapping relationship between a position information and a specific moving signal, it indicates that when the projection device10was previously used in an environment matching the position information, the at least one processor110and the driving member150may control the projection lens module170to move according to the specific moving signal. Accordingly, the at least one processor110may proceed to execute step S303. By contrast, if the mapping relationship between the position information and the specific moving signal does not exist, it indicates that the projection device10is used in an environment matching the above position information for the first time, and the at least one processor110executes step S304.

In step S303, the at least one processor110may generate a moving signal according to the mapping relationship and transmit the moving signal to the driving member150. The driving member150may control the projection lens module170according to the moving signal to move relative to the projection device10, where the moving distance of the projection lens module170may be instructed by the moving signal.

For instance, it is assumed that the storage medium120has stored a mapping relationship between position information and a specific moving signal, where the position information indicates that when the projection device10was used before, the distance between the projection device10and the projection target is 50 cm, and the specific moving signal is, for instance, an instruction of controlling the projection lens module170to move relative to the projection device10by 10 cm. If the position information obtained by the at least one processor110in step S301matches the stored mapping relationship, it indicates that the distance between the current projection device10and the projection target is also 50 cm. Accordingly, the at least one processor110may generate the specific moving signal to allow the driving member150to control the projection lens module170to move relative to the projection device10by 10 cm. Thereby, the image projected by the projection device10may be adjusted to the projection size which the user is accustomed to.

In step S304, the at least one processor110may obtain a moving range of the projection lens module170according to the position information (e.g., 0 mm to 120 mm). The storage medium120may store a lookup table. The lookup table may record the mapping relationships between parameters, such as the position information of the projection device10, the moving range of the projection lens module170, and/or a range of the projection size of an image projected by the projection device10. Table 1 is an example of the lookup table. The at least one processor110may obtain the moving range corresponding to the position information by looking up the lookup table according to the position information. For instance, if the position information is 50 cm, the at least one processor110may look up the lookup table and obtain the moving range of the projection lens module170as 0 mm to 120 mm. When the position information is 40 cm, it means that the projection device10is placed at a position closer to the projection target. Accordingly, the maximum projection size of the image projected by the projection device10is, for instance, 110 inches. In the embodiment, the projection size of the image projected by the projection device10is, for instance, set to be at least 100 inches. Accordingly, when the position information is 40 cm, the minimum value of the moving range of the projection lens module170is 100 mm, so that the projection size is at least 100 inches.

TABLE 1Position informationMoving rangeRange of the projection size(cm)(mm)(inches)400100-1200100-11005000-1200100-13006000-200120-1300

In step S305, the at least one processor110may generate a moving signal according to the position information and transmit the moving signal to the driving member150. The driving member150may control the projection lens module170to move relative to the projection device10according to the moving signal, where the moving distance of the projection lens module170may be instructed by the moving signal. The at least one processor110may generate the moving signal according to the moving range. The minimum value of the moving range corresponds to the minimum projection size of the image projected by the projection device10, and the maximum value of the moving range corresponds to the maximum projection size of the image projected by the projection device10. The at least one processor110may generate the moving signal to control the projection lens module170to move within the moving range. In an embodiment, the at least one processor110may generate the moving signal according to the minimum value of the moving range, so that the projection device10projects an image of the minimum projection size. For instance, when the position information is 40 cm, the moving range of the projection lens module170is 100 mm to 120 mm. The at least one processor110may generate the moving signal according to the minimum value of the moving range (i.e., 100 mm) and transmit the moving signal to the driving member150. The driving member150may control the projection lens module170to move relative to the projection device10by 100 mm according to the moving signal, so that the projection device10may project an image of the minimum projection size (i.e., 100 inches). When the position information is 50 cm, since the minimum value of the moving range of the projection lens module170is 0 mm, the moving signal generated by the at least one processor110may be an instruction of not moving the projection lens module170, and thereby the projection device10projects an image of the minimum projection size (i.e., 100 inches).

In step S306, the at least one processor110projects an OSD menu having a range of the projection size corresponding to the moving range through the projection lens module170. For instance, when the position information is 50 cm, the OSD menu may be displayed within the range of the projection size of the image projected by the projection lens module170as 100 inches to 130 inches for the user to choose from.

In step S307, the at least one processor110receives a user command through the input device130. The user command refers to the user selecting a specific projection size from the range of the projection size. The at least one processor110may generate a moving signal according to the user command and the moving range, where the moving signal is an instruction of controlling the projection lens module170to move according to the moving distance within the moving range. For instance, if the position information is 50 cm, the user command refers to selecting 130 inches as the projection size of the projection device10from the range of the projection size from 100 inches to 130 inches corresponding to the moving range from 0 mm to 120 mm, and the at least one processor110may obtain a moving distance as 120 mm corresponding to the projection lens module170of the projection size of 130 inches according to the lookup table. The at least one processor110then further generates a moving signal corresponding to the moving distance of 120 mm.

In step S308, the at least one processor110may record the mapping relationship between the position information and the aforementioned moving signal in the storage medium120as a use record. For instance, the at least one processor110may record the mapping relationship between the position information of 50 cm and the moving signal corresponding to the moving distance of 120 mm in the storage medium120.

In step S309, the at least one processor110may transmit the moving signal to the driving member150. The driving member150may control the projection lens module170to move relative to the projection device10according to the moving signal. For instance, the driving member150may control the projection lens module170to move relative to the projection device10(the housing100) by 120 mm according to the moving signal.

In step S310, the at least one processor110may periodically detect the position information measured by the sensor140. In step S311, the at least one processor110may determine whether the position information has changed. If the at least one processor110determines that the position information changes, it means that the projection device10has been moved. Accordingly, the at least one processor110may execute step S304again to generate a new moving signal according to the changed position information and enable the driving member170to control the projection lens module170to move relative to the projection device10according to the new moving signal. If the at least one processor110determines that the position information has not changed, the at least one processor110may execute step S310again to continuously detect the position information.

FIG.4is a flowchart illustrating a control method of the projection device10according to another embodiment of the invention. In step S401, the position information of the projection device is obtained by the sensor. In step S402, the first moving signal is generated by the at least one processor according to the position information. In step S403, the projection lens module is controlled by the driving member to move relative to the projection device according to the first moving signal.

To sum up, the projection device provided in one or more embodiments of the invention may obtain the distance between the projection device and the projection target through the sensor and determine the appropriate range of the projection size for the projected image according to the distance. The projection device may control the projection lens module through the driving member to move relative to the projection device, so as to enlarge or reduce the size of the projected image within the appropriate range of the projection size. Thereby, the projection size may be adjusted in no need of moving the entire projection device, and by extending or retracting the projection lens module, the projection device may be disposed at a position closer to the projection target, so as to prevent the waste of the available space. After the projected image is adjusted, the projection device may store the mapping relationship associated with the measurement results of the sensor and the size of the projected image for future use.