An electronic teaching aid
By designing the main body, projector, host, and control unit of the electronic teaching aid, and combining radar and casters, interactive games based on ground projection are realized. This solves the problems of insufficient interactivity and poor portability of existing equipment, enhances students' interest in participation and the portability of the equipment, while protecting students' eyesight and extending the life of the equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WEIFANG LOKOMO PRECISION IND
- Filing Date
- 2026-03-31
- Publication Date
- 2026-05-29
AI Technical Summary
Existing interactive entertainment devices lack targeted teaching adaptation capabilities, have insufficient interactivity, fail to stimulate students' interest, and are poorly portable, posing a risk of vision damage.
Design an electronic teaching tool, including a main body, a projector, a host, and a control unit. The projector lens faces the ground and is combined with radar and casters to realize interactive games projected onto the ground. It is equipped with a heat dissipation system to protect the projector lens and improve portability.
Interactive games using ground projection enhance student engagement, address the issue of insufficient interaction, improve portability, protect students' eyesight, and extend equipment lifespan.
Smart Images

Figure CN122116702A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of optical product technology, and more specifically, to an electronic teaching aid. Background Technology
[0002] In daily teaching for K-12 students, knowledge consolidation, learning feedback, and improving student participation are core challenges, especially for lower-grade students. Traditional methods such as after-school exercises, classroom questioning, and written tests are often monotonous and lack engagement, failing to motivate students and resulting in ineffective knowledge consolidation, thus hindering the achievement of the "learning through play" teaching goal. Currently, the education sector urgently needs a device that deeply integrates teaching content with interactive entertainment, guiding students to actively participate in knowledge consolidation through engaging and enjoyable formats, and enabling them to master knowledge points through interaction.
[0003] Currently available related equipment has obvious shortcomings; for example, conventional interactive entertainment equipment focuses on entertainment and lacks targeted teaching adaptation capabilities. It cannot present the question bank content in a gamified form, has serious lack of interactivity, cannot combine teaching content with students' physical movements, cannot get students "moving" during the question-answering process, and is difficult to stimulate students' interest in participation.
[0004] In addition, existing interactive and teaching equipment is not portable, and switching between application scenarios is cumbersome, making it difficult to flexibly adapt to the usage needs of different places such as classrooms and activity rooms. Furthermore, the light output ports of some floor projection equipment lack effective protection, and the brightness is too high, which can easily cause vision damage to students if they look at them directly for a long time, posing a safety hazard.
[0005] In view of this, a new technical solution is needed to solve at least one of the above-mentioned technical problems. Summary of the Invention
[0006] One objective of this application is to provide a new technological solution for electronic teaching aids.
[0007] According to a first aspect of this application, an electronic teaching aid is provided, the electronic teaching aid comprising: The main body includes a support body and a first housing. The support body is disposed inside the first housing, and the first housing has a window that faces the ground. A projector, wherein the projector is mounted on the support body and the lens of the projector is correspondingly arranged with respect to the window portion; The host is mounted on the support body and is signal-connected to the projector; The control unit is rotatably connected to the main body and disposed at the end of the main body away from the ground; the control unit is signal-connected to the host computer and is configured to receive user operations to control the host computer.
[0008] Optionally, the front side of the first housing is provided with a recessed area, and the first housing is formed with a mounting top surface corresponding to the recessed area, and the window is opened on the mounting top surface.
[0009] Optionally, the electronic teaching aid further includes a connecting part, through which the control part is rotatably connected to the main body.
[0010] Optionally, the connecting part includes a connecting neck, a connecting piece, a hinge, and a mounting piece. The mounting piece, hinge, and connecting piece are disposed inside the first housing. The connecting neck extends into the first housing, and the control part is mounted on the first end of the connecting neck that is exposed outside the first housing. One end of the connecting piece is connected to the second end of the connecting neck, the other end of the connecting piece is connected to the first leaf of the hinge, the second leaf of the hinge is connected to the mounting piece, and the mounting piece is fixedly disposed within the first housing.
[0011] Optionally, the control unit includes a second housing, a touch screen, and a camera. The touch screen and the camera are mounted on the second housing, and both the touch screen and the camera are signal-connected to the host.
[0012] Optionally, the electronic teaching aid also includes a radar and a set of casters, which are located at the bottom of the main body.
[0013] Optionally, the electronic teaching aid further includes a heat sink, which is disposed within the first housing and close to the projector.
[0014] Optionally, the heat sink includes a heat sink pipe and a heat sink fan. The heat sink pipe is installed on the support body, one end of the heat sink pipe is connected to the air outlet of the projector, and the heat sink fan is installed on the other end of the heat sink pipe and is connected to the heat sink hole of the first housing.
[0015] Optionally, the support includes a bracket, a first mounting plate, and a second mounting plate, both of which are connected to the bracket, with the first mounting plate positioned above the second mounting plate; the projector is mounted on the first mounting plate, and the host is mounted on the second mounting plate.
[0016] Optionally, the support body further includes a tray, which is connected to the bracket and located between the first mounting plate and the second mounting plate, and is used to support the projector.
[0017] The electronic teaching aid provided in this application embodiment establishes a core structure for interactive ground projection through the coordinated operation of the main body, projector, host, and control unit. The projector's lens is positioned correspondingly to the window facing the ground, which is crucial for achieving interactive entertainment. This layout allows the projector to present the question bank stored in the host in the form of a ground projection, enabling the game to proceed in a falling selection manner. Students need to avoid incorrect options and step on the correct options from the ground projection according to the question requirements. This perfectly matches the interactive format that students prefer, allowing them to move while selecting answers. After stepping on the correct option, the host can control the projector to display corresponding feedback effects (such as light changes, screen prompts, etc.), effectively enhancing the interactive entertainment of the electronic teaching aid, fully mobilizing students' participation, and solving the problems of insufficient interaction and difficulty in stimulating student interest in existing teaching equipment.
[0018] Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description
[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.
[0020] Figure 1 The diagram shown is a schematic representation of the overall structure of the electronic teaching aid according to an embodiment of this application. Figure 2 The diagram shown is an exploded view of the electronic teaching aid according to an embodiment of this application. Figure 3 The diagram shown is a partial structural schematic of an electronic teaching aid according to an embodiment of this application; Figures 4a-4b The diagram shown is a schematic representation of the rotation state of the electronic teaching aid according to an embodiment of this application.
[0021] Explanation of reference numerals in the attached figures: 1. Main body; 11. Support body; 111. Bracket; 112. First mounting plate; 113. Second mounting plate; 114. Support plate; 115. Base; 12. First housing; 13. Protective cover; 120. Window; 121. Recessed area; 1211. Mounting top surface; 2. Projector; 3. Main unit; 4. Control unit; 41. Second housing; 42. Touch screen; 43. Camera; 5. Connecting part; 51. Connecting neck; 52. Connecting piece; 53. Hinge; 54. Mounting piece; 6. Radar; 7. Universal wheel set; 8. Heat sink; 81. Heat dissipation pipe; 82. Cooling fan; 91. Power switch; 92. Light strip. Detailed Implementation
[0022] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components and steps set forth in these embodiments do not limit the scope of the present application.
[0023] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.
[0024] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.
[0025] In all the examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.
[0026] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.
[0027] Reference Figures 1-4b As shown, according to one embodiment of this application, an electronic teaching aid is provided. The electronic teaching aid includes a main body 1, a projector 2, a host 3, and a control unit 4. The main body 1 includes a support body 11 and a first housing 12. The support body 11 is disposed inside the first housing 12. The first housing 12 has a window 120, which faces the ground. The projector 2 is mounted on the support 11, and the lens of the projector 2 is correspondingly arranged with the window 120; the host 3 is mounted on the support 11, and the host 3 is signal connected to the projector 2. The control unit 4 is rotatably connected to the main body 1 and is disposed at the end of the main body 1 away from the ground; the control unit 4 is signal connected to the host 3, and the control unit 4 is configured to receive user operations to control the host 3.
[0028] In the electronic teaching aid provided in this application embodiment, the main body 1 serves as the mounting carrier for the entire electronic teaching aid, playing a role in supporting and protecting the internal components. The main body 1 includes a support body 11 and a first housing 12. The support body 11 is disposed inside the first housing 12, providing a stable mounting reference for the projector 2 and the host 3, ensuring the structural stability of the components after installation. The first housing 12 has a window 120, which faces the ground, providing a dedicated channel for the light projection of the projector 2, ensuring that the image projected by the projector 2 can be accurately and stably projected onto the ground, providing basic scene support for the subsequent interactive games.
[0029] Projector 2 is mounted on support 11, and the lens of projector 2 is correspondingly set with window 120. This corresponding setting, together with the layout of window 120 facing the ground, enables projector 2 to accurately project the game screen, answer questions, and options stored in host 3 onto the ground, meeting the needs of interactive floor projection. Host 3 is mounted on support 11 and is signal-connected to projector 2. Host 3 is not only used to store game and answer information, but also to receive control commands from control unit 4 to control the switching of projected content, game start and pause, etc. It is the control core and data storage core of the entire electronic teaching aid, providing data and control support for the realization of gamified answering scenarios.
[0030] The control unit 4 is rotatably connected to the main body 1 and is located at the end of the main body 1 away from the ground. The control unit 4 is signal-connected to the host 3 and is configured to receive user operations to control the host 3. Users can use the control unit 4 to perform operations such as selecting a question bank, starting a game, and switching screens, achieving flexible control of the entire electronic teaching aid and ensuring the smooth operation of interactive teaching scenarios. The rotatable connection design allows the angle of the control unit to be flexibly adjusted according to the user's operation; for example, referring to… Figure 4a As shown, the control unit 4 can be rotated to a near-horizontal position, thereby facilitating user operation; and, referring to... Figure 4b As shown, the control unit 4 can also be rotated to a near-vertical position to facilitate user face recognition.
[0031] The electronic teaching aid provided in this application embodiment establishes a core structure for interactive ground projection through the coordinated operation of the main body 1, projector 2, host 3, and control unit 4. The lens of the projector 2 is positioned corresponding to the window 120 facing the ground, which is crucial for achieving interactive entertainment. This layout allows the projector 2 to present the question bank content stored in the host 3 in the form of ground projection, enabling the game to proceed through a falling selection method. Students need to avoid incorrect options and step on the correct options among the options projected on the ground according to the question requirements. This perfectly matches the interactive format that students prefer, allowing them to move while selecting answers. After stepping on the correct option, the host 3 can control the projector 2 to display corresponding feedback effects (such as light changes, screen prompts, etc.), effectively enhancing the interactive entertainment of the electronic teaching aid, fully mobilizing students' participation, and solving the problems of insufficient interaction and difficulty in stimulating student interest in existing teaching equipment. Secondly, the support body 11 of the main body 1 cooperates with the first shell 12, which not only ensures the installation stability of the internal components, but also ensures that the light from the projector 2 is accurately projected onto the ground through the orientation design of the window 120, providing a scene guarantee for the smooth development of interactive games; the rotating connection design of the control unit 4 improves the ease of operation and meets the operation needs of different users; the signal connection between the host 3, the projector 2, and the control unit 4 realizes the integrated control of the equipment, laying a structural foundation for subsequent question bank editing, game operation, and learning data collection, while taking into account both teaching practicality and ease of operation.
[0032] Reference Figure 1 , Figure 2 As shown, in one embodiment, the front side of the first housing 12 is provided with a recessed area 121, and the first housing 12 is formed with a mounting top surface 1211 corresponding to the recessed area 121, and the window portion 120 is formed on the mounting top surface 1211.
[0033] In this specific example, because the light output port of the projector 2 has a high brightness, prolonged direct viewing can damage eyesight. Therefore, by providing a recessed area 121 on the front side of the first housing 12 and opening a window 120 on the mounting top surface 1211 of the recessed area 121, the light output port of the projector 2 is hidden within the recessed area 121. During use, the user cannot see the light output port from directly in front, effectively preventing students from directly viewing the light emitted by the projector 2 and causing eye damage, thus improving the safety of using the electronic teaching aid. Simultaneously, the design of the recessed area 121 also provides some dust and impact protection for the projector lens, reducing dust ingress and damage from external impacts, extending the projector's lifespan. Furthermore, the mounting top surface 1211 provides a stable opening position for the window 120, ensuring the stability of the projector's light projection without affecting the overall structural aesthetics of the first housing 12.
[0034] Reference Figure 2 As shown, in one embodiment, the electronic teaching aid further includes a connecting part 5, and the control part 4 is rotatably connected to the main body part 1 through the connecting part 5.
[0035] In this specific example, the connecting part 5 serves as a connecting medium between the control part 4 and the main body 1, enabling stable rotation between the two. Compared to the direct rotational connection between the control part 4 and the main body 1, the setting of the connecting part 5 can reduce wear at the rotational connection, improve the stability and service life of the rotational structure, and at the same time, the rotation angle range of the control part 4 can be flexibly adjusted, further optimizing the user's operating experience.
[0036] Reference Figure 2 As shown, in one embodiment, the connecting part 5 includes a connecting neck 51, a connecting piece 52, a hinge 53, and a mounting piece 54. The mounting piece 54, the hinge 53, and the connecting piece 52 are disposed inside the first housing 12. The connecting neck 51 extends into the first housing 12, and the operating part 4 is mounted on the first end of the connecting neck 51 that is exposed outside the first housing 12. One end of the connecting piece 52 is connected to the second end of the connecting neck 51, and the other end of the connecting piece 52 is connected to the first leaf of the hinge 53. The second leaf of the hinge 53 is connected to the mounting piece 54, and the mounting piece 54 is fixedly disposed within the first housing 12.
[0037] In this specific example, the mounting plate 54 is fixedly disposed within the first housing 12, providing a stable mounting reference for the entire connection. For example, the mounting plate 54 is fixedly connected to the support body 11. The hinge 53, as the core component for rotation, is connected to the connecting plate 52 via the first plate and to the mounting plate 54 via the second plate, enabling flexible rotation of the connecting plate 52, the connecting neck 51, and the control part 4. The connecting plate 52 is used to connect the connecting neck 51 and the hinge 53, playing a role in force transmission and ensuring smooth rotation. The connecting neck 51 is used to install the control part 4, and part of it extends into the first housing 12, which not only ensures the stability of the connection but also avoids the connection structure from being exposed, improving the overall aesthetics of the equipment, while protecting the connection part from external damage.
[0038] Reference Figure 2 As shown, in one embodiment, the control unit 4 includes a second housing 41, a touch display screen 42, and a camera 43. The touch display screen 42 and the camera 43 are mounted on the second housing 41, and both the touch display screen 42 and the camera 43 are signal connected to the host 3.
[0039] In this specific example, the second housing 41 serves as the mounting carrier for the touch display screen 42 and the camera 43, providing support and protection while enhancing the overall structural strength of the control unit 4. The touch display screen 42 is used for operations such as selecting games, switching question banks, and setting parameters, providing users with an intuitive and convenient operating interface without the need for additional operation buttons, simplifying the operation process and adapting to the operating habits of teachers and students. The camera 43 is used for user facial recognition, which, combined with the host's learning analysis function, enables rapid identification of students, facilitating the accurate collection of each student's answer data, play records, and other information. Furthermore, the student ID input method allows different schools to choose according to their own circumstances.
[0040] Reference Figure 1 , Figure 3 As shown, in one embodiment, the electronic teaching aid further includes a radar 6 and a set of universal wheels 7, which are disposed at the bottom of the main body 1.
[0041] In this specific example, radar 6 is used to capture the user's movements. Combined with the game screen projected onto the ground, it enables real-time interaction between students and the game. For example, students answer questions by stepping on the options on the ground. After the radar captures the stepping action, it transmits the signal to the host 3. The host 3 controls the game screen to present the corresponding feedback effect, further enhancing the interactive fun and solving the problem of insufficient interaction in existing teaching equipment. The omnidirectional wheel set 7 allows the entire electronic teaching aid to move flexibly and easily switch application scenarios, such as moving it from the classroom to the activity room. Compared with conventional ground projection equipment on the market, it greatly improves portability and meets the needs of schools in multiple scenarios.
[0042] Reference Figure 3 As shown, in one embodiment, the electronic teaching aid further includes a heat sink 8, which is disposed inside the first housing 12 and close to the projector 2.
[0043] In this specific example, since the projector 2 generates a lot of heat during long-term operation, if the heat cannot be dissipated in time, the temperature of the projector 2 will become too high, affecting the projection effect and even damaging the internal components of the projector, thus shortening the service life of the device. Therefore, the heat sink 8 is placed close to the projector 2, which can quickly absorb the heat generated by the projector and dissipate the heat, ensuring that the projector is always at a suitable operating temperature, ensuring the stability and clarity of the projected image, preventing the projector from being damaged due to overheating, extending the service life of the projector, and ensuring the smooth progress of interactive teaching.
[0044] Reference Figure 3As shown, in one embodiment, the heat sink 8 includes a heat dissipation pipe 81 and a heat dissipation fan 82. The heat dissipation pipe 81 is installed on the support body 11, one end of the heat dissipation pipe 81 is connected to the air outlet of the projector 2, and the heat dissipation fan 82 is installed on the other end of the heat dissipation pipe 81 and is connected to the heat dissipation hole of the first housing 12.
[0045] In this specific example, the heat generated by the projector 2 enters the heat dissipation pipe 81 through the air outlet. The heat dissipation pipe 81 plays the role of heat conduction and concentration, guiding the heat to the cooling fan 82. When the cooling fan 82 is working, it generates airflow, which discharges the heat in the heat dissipation pipe 81 to the outside of the device through the heat dissipation holes of the first housing 12, forming a complete heat dissipation channel and improving heat dissipation efficiency.
[0046] Thus, the heat dissipation pipe 81 and the cooling fan 82 work together to form a highly efficient heat dissipation channel, greatly improving heat dissipation efficiency and ensuring that the projector 2 can work stably for a long time. The heat dissipation pipe 81 is directly connected to the air outlet of the projector, which can quickly absorb the heat generated by the projector and prevent heat from accumulating in the first housing 12. The cooling fan 82 is connected to the heat dissipation holes of the first housing 12 to ensure that heat is discharged smoothly. At the same time, the structure is simple, easy to process and assemble, and reduces production costs.
[0047] Reference Figure 3 As shown, in one embodiment, the support 11 includes a bracket 111, a first mounting plate 112 and a second mounting plate 113. The first mounting plate 112 and the second mounting plate 113 are both connected to the bracket 111, and the first mounting plate 112 is located above the second mounting plate 113. The projector 2 is mounted on the first mounting plate 112, and the host 3 is mounted on the second mounting plate 113.
[0048] In this specific example, the bracket 111, as the core component of the support body 11, provides stable support for the first mounting plate 112 and the second mounting plate 113, ensuring the overall structural strength of the support body 11. The first mounting plate 112 and the second mounting plate 113 are arranged in layers to install the projector 2 and the host 3 separately. On the one hand, this can avoid mutual interference between the two. For example, the heat generated by the projector 2 will not be directly transferred to the host 3, protecting the internal electronic components of the host 3. On the other hand, it makes the spatial layout inside the first housing 12 more reasonable, which facilitates the installation of subsequent heat dissipation components, connecting parts and other components, and also facilitates the inspection and maintenance of the equipment.
[0049] Reference Figure 3As shown, in one embodiment, the support 11 further includes a tray 114, which is connected to the bracket 111 and is located between the first mounting plate 112 and the second mounting plate 113. The tray 114 is used to support the projector 2.
[0050] In this specific example, the projector 2 is mounted on the first mounting plate 112, and the support plate 114 supports the projector 2 from below, further improving the installation stability of the projector 2 and preventing the projector 2 from becoming loose or shaking due to long-term use or during equipment movement. This ensures that the lens of the projector 2 is always aligned with the window 120 of the first housing 12, guaranteeing the accuracy of the projected image. At the same time, the support plate also plays a certain role in buffering, reducing the damage to the projector 2 caused by vibration during equipment movement.
[0051] In addition, the support body 11 also includes a base 115, a bracket 111 is disposed on the upper surface of the base 115, and the radar 6 and the caster wheel assembly 7 are disposed on the lower surface of the base 115; a protective cover 13 is sleeved on the outside of the base 115, and a power switch 91 and a light strip 92 are installed on the protective cover 13.
[0052] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.
Claims
1. An electronic teaching aid, characterized in that, The electronic teaching aids include: The main body (1) includes a support (11) and a first shell (12). The support (11) is disposed inside the first shell (12). The first shell (12) has a window (120) facing the ground. Projector (2), the projector (2) is mounted on the support (11), and the lens of the projector (2) is correspondingly set with the window (120); The host (3) is mounted on the support (11) and is connected to the projector (2) via signal. The control unit (4) is rotatably connected to the main body (1) and is located at one end of the main body (1) away from the ground; the control unit (4) is signal connected to the host (3) and is configured to receive user operations to control the host (3).
2. The electronic teaching aid according to claim 1, characterized in that, The front side of the first housing (12) is provided with a recessed area (121), and the first housing (12) is provided with a mounting top surface (1211) corresponding to the recessed area (121), and the window portion (120) is opened on the mounting top surface (1211).
3. The electronic teaching aid according to claim 1, characterized in that, The electronic teaching aid also includes a connecting part (5), and the control part (4) is rotatably connected to the main body part (1) through the connecting part (5).
4. The electronic teaching aid according to claim 3, characterized in that, The connecting part (5) includes a connecting neck (51), a connecting piece (52), a hinge (53), and a mounting piece (54). The mounting piece (54), the hinge (53), and the connecting piece (52) are disposed inside the first housing (12). The connecting neck (51) extends into the first housing (12). The operating part (4) is installed at the first end of the connecting neck (51) exposed outside the first housing (12). One end of the connecting piece (52) is connected to the second end of the connecting neck (51), the other end of the connecting piece (52) is connected to the first leaf of the hinge (53), the second leaf of the hinge (53) is connected to the mounting piece (54), and the mounting piece (54) is fixedly disposed in the first housing (12).
5. The electronic teaching aid according to any one of claims 1 to 4, characterized in that, The control unit (4) includes a second housing (41), a touch screen (42) and a camera (43). The touch screen (42) and the camera (43) are mounted on the second housing (41), and both the touch screen (42) and the camera (43) are signal connected to the host (3).
6. The electronic teaching aid according to claim 1, characterized in that, The electronic teaching aid also includes a radar (6) and a set of universal wheels (7), which are located at the bottom of the main body (1).
7. The electronic teaching aid according to claim 1, characterized in that, The electronic teaching aid also includes a heat sink (8), which is disposed inside the first housing (12) and close to the projector (2).
8. The electronic teaching aid according to claim 7, characterized in that, The heat sink (8) includes a heat sink pipe (81) and a heat sink fan (82). The heat sink pipe (81) is installed on the support body (11). One end of the heat sink pipe (81) is connected to the air outlet of the projector (2). The heat sink fan (82) is installed on the other end of the heat sink pipe (81). The heat sink fan (82) is connected to the heat dissipation hole of the first housing (12).
9. The electronic teaching aid according to claim 1, characterized in that, The support (11) includes a bracket (111), a first mounting plate (112) and a second mounting plate (113). The first mounting plate (112) and the second mounting plate (113) are both connected to the bracket (111), and the first mounting plate (112) is located above the second mounting plate (113). The projector (2) is mounted on the first mounting plate (112), and the host (3) is mounted on the second mounting plate (113).
10. The electronic teaching aid according to claim 9, characterized in that, The support (11) also includes a tray (114), which is connected to the bracket (111) and is located between the first mounting plate (112) and the second mounting plate (113). The tray (114) is used to support the projector (2).