CN212685062U - Electronic blackboard for multimedia classroom - Google Patents

Abstract

The utility model discloses an electronic blackboard for multimedia classroom, including an at least clipboard and an at least interactive board, clipboard and interactive board are fixed through respective frame work dress respectively, backlight unit further includes base plate, LED lamp area, light guide plate, membrane and reflection paper of homogenizing, the reflection paper is located between base plate and the light guide plate, LED lamp area includes a plurality of LED components and circuit board, LED components equidistant installation is in a side surface of circuit board, the lower extreme of support bar has the first turn-ups portion of bending in a reverse direction on one side of the light guide plate earlier on, the lower surface of this first turn-ups portion and the surface contact of base plate and this first turn-ups portion and base plate fixed connection, the support bar is the aluminium support bar. The utility model discloses multimedia classroom is with electronic blackboard avoids influencing the device performance because of the heat dissipation is not smooth, can also reduce other heat radiation module's use simultaneously, has both practiced thrift the cost, can attenuate the thickness of equipment again, optimize the user experience of product.

Description

Electronic blackboard for multimedia classroom

Technical Field

The utility model relates to an electronic blackboard for multimedia classroom belongs to education and equips technical field.

Background

Teaching lessons in the form of chalk used in conjunction with a blackboard has long been a very important position in the field of education. However, with the development of science and technology and the deeper understanding of some diseases, the disadvantages of the traditional chalk teaching are also gradually paid more attention. For example, chalk dust generated by chalk during writing and erasing is mainly calcium sulfate or calcium carbonate. Inhalation of the trachea can cause discomfort in the nose, throat and throat, and lung cancer is more likely to be caused if the trachea is kept in the environment for a long time. Although "dust-free" chalk is also available on the market, in practical application, the pollution reduction effect on the chalk dust is not very obvious.

In addition, in the campus nowadays, multimedia classrooms and electronic blackboards are common, wherein the general components of the multimedia classrooms include a multimedia computer, a liquid crystal projector, a projection screen, an audio device and the like. During actual teaching, a multimedia computer is used for displaying pre-prepared teaching materials through projection of a projector, and meanwhile, the cooperation of sound and man-machine interaction operation between a user and the computer are added according to needs to complete the teaching or training process. It can be seen that the multimedia teaching apparatus in the prior art also has some drawbacks, such as: the multimedia equipment is more, and a projector, a projection screen and the like need to be independently equipped; the projection screen is generally white and can not be used in an environment with bright light; the function is single, and the expansibility is avoided. The existing electronic blackboard is usually integrated with the display screen as a whole into the blackboard, which is not beneficial to the weight reduction, thinning and installation of the weight of the blackboard.

Disclosure of Invention

The utility model aims at providing an electronic blackboard is used in multimedia classroom, this electronic blackboard is used in multimedia classroom avoids influencing the device performance because of the heat dissipation is not smooth, can also reduce other heat dissipation module's use simultaneously, has both practiced thrift the cost, can attenuate the thickness of equipment again, optimize the user experience of product.

In order to achieve the above purpose, the utility model adopts the technical scheme that: an electronic blackboard for a multimedia classroom comprises at least one writing board and at least one interactive board, wherein the writing board and the interactive board are respectively installed and fixed through respective outer frame frames;

the interactive board comprises a writing panel, a touch control film, a liquid crystal panel and a backlight module, wherein the touch control film is positioned between the writing panel and the liquid crystal panel and is pasted on one surface of the writing panel;

the periphery outer sides of the medium plate and the liquid crystal panel are respectively provided with a plurality of fixed blocks, the fixed blocks are fixed at the periphery edges of the writing panel or the touch control film, the periphery outer sides of the medium plate and the liquid crystal panel are respectively provided with a cover plate connected with the fixed blocks, one side of the cover plate is connected with the fixed blocks, and the other side of the cover plate is connected with the periphery edges of the medium plate and the liquid crystal panel in a pressing way;

the surface of one side, close to the dielectric plate, of the fixed block is connected with a buffer strip used for being in contact with the side face of the dielectric plate, the middle parts of the cover plates positioned on the left side and the right side of the dielectric plate are provided with downward convex strip parts, the convex strip parts are positioned between the fixed block and the liquid crystal panel and close to one end of the liquid crystal panel, and buffer layers are arranged between the convex strip parts and the dielectric plate and between the convex strip parts and the liquid crystal panel;

the backlight module further comprises a substrate, an LED lamp strip, a light guide plate, a light homogenizing film and reflecting paper, wherein the reflecting paper is positioned between the substrate and the light guide plate, the light homogenizing film is positioned on the surface of one side of the light guide plate opposite to the substrate, the LED lamp strip is respectively arranged on the upper side and the lower side of the light guide plate and is respectively arranged on the substrate through a supporting strip;

the LED lamp strip comprises a plurality of LED elements and a circuit board, the LED elements are arranged on the surface of one side of the circuit board at equal intervals, the surface of the other side of the circuit board is connected with the supporting strips in an adhesive mode, and one side of the circuit board provided with the LED elements is arranged face to face with the side surface of the light guide plate;

the movable frame is characterized by further comprising at least one movable plate, a linear guide rail and at least one movable block which is distributed at intervals are arranged between the upper end face of the movable plate and the upper end face of the outer frame, and the linear guide rail is embedded into the movable block or the movable block is embedded into the linear guide rail;

the lower end of the supporting strip is provided with a first flanging part which is bent back to one side of the light guide plate, the lower surface of the first flanging part is in contact with the surface of the substrate, the first flanging part is fixedly connected with the substrate, and the supporting strip is an aluminum supporting strip.

The further improved scheme in the technical scheme is as follows:

1. in the scheme, the diffusion film and the brightness enhancement film are stacked above the light-homogenizing film.

2. In the above solution, an elastic cushion layer is arranged between the lower surface of the cover plate and the upper surface of the liquid crystal panel.

3. In the above scheme, the four cover plates are respectively connected with the fixing block through a screw.

4. In the above scheme, the buffer strip is a foam buffer strip or a silica gel buffer strip.

5. In the above scheme, the buffer layer is a foam buffer layer or a silica gel buffer layer.

6. In the above scheme, the upper end of the supporting bar is provided with a second flanging part which is bent towards one side of the light guide plate, and the lower surface of the second flanging part is in contact connection with the light-equalizing film above the light guide plate.

7. In the scheme, the left side and the right side of the light guide plate are respectively provided with a pressing strip, one end of each pressing strip is arranged on the base plate, and the other end of each pressing strip is in contact connection with the light equalizing film on the light guide plate.

8. In the scheme, the cross section of the pressing strip is a Z-shaped cross section.

Because of above-mentioned technical scheme's application, compared with the prior art, the utility model have the following advantage:

1. the utility model discloses electronic blackboard for multimedia classroom, the lower extreme of its support bar has the first turn-ups portion of bending back to one side of light guide plate earlier on, the lower surface of this first turn-ups portion and the surface contact of base plate and this first turn-ups portion and base plate fixed connection, the support bar is the aluminium support bar, through the setting of aluminium support bar and its first turn-ups portion, can be with the heat of LED lamp area lasting, quick transfer to large tracts of land base plate, realized producing the quick, even heat dissipation of heat to LED lamp area, avoid using the equipment of backlight unit of this invention, such as the touch-control blackboard influences other device performances because the heat dissipation is not smooth, can also reduce the use of other heat dissipation module simultaneously, both practice thrift the cost, can thin the thickness of equipment, optimize the user experience of product again; furthermore, the upper end of the supporting bar is provided with a second flanging part bent towards one side of the light guide plate, the lower surface of the second flanging part is in contact connection with the light equalizing film above the light guide plate, and the supporting bar is enabled to have the effect of limiting the light guide plate and the optical diaphragm at the same time through the arrangement of the second flanging part, so that the positioning of the light guide plate and the optical diaphragm is realized under the condition of not increasing any cost, and the production efficiency is improved.

2. The utility model discloses electronic blackboard for multimedia classroom, it peels off liquid crystal display panel from traditional LCD, and assembles it as independent module with writing panel, touch membrane through the apron, cooperates with backlight unit, just can realize touch-control and display operation, has simplified the flow of production, the processing of being convenient for, very big improvement production efficiency, saving manufacturing cost; meanwhile, the deformation of the dielectric plate and the liquid crystal panel under the influence of environmental factors can be reduced, so that the display definition and the touch precision are improved, and the user experience is good; furthermore, the liquid crystal panel is convenient to maintain and replace, the replacement of the liquid crystal panel cannot generate adverse effects on other components such as the touch control film, and the cost of maintenance is reduced.

3. The utility model discloses electronic blackboard for multimedia classroom, one side surface that its fixed block is close to the dielectric-slab is connected with one and is used for the buffering strip with the side contact of dielectric-slab, the setting of buffering strip, both can prevent the hard contact between dielectric-slab and the fixed block, the protection dielectric-slab, still provide the adaptability space for the expend with heat and contract with cold of dielectric-slab under the influence of environmental factor, make the dielectric-slab can not receive the external force restriction freely to realize expend with heat and contract with cold, thereby guarantee the stability of dielectric-slab materialization nature, the life of extension dielectric-slab.

4. The utility model discloses multimedia classroom uses electronic blackboard, it is located the apron middle part of the dielectric slab left and right sides has a decurrent bulge strip, and this bulge strip is located between fixed block and the liquid crystal display panel and is close to liquid crystal display panel's one end, and the setting of apron bulge strip both can strengthen the physical properties and the mechanical strength of apron under the condition that does not increase apron thickness, improves the stability to liquid crystal display panel, dielectric slab installation, can play good limiting displacement to liquid crystal display panel again, can not restrict the free expend with heat and contract with cold of dielectric slab simultaneously.

Drawings

FIG. 1 is a schematic structural view of an electronic blackboard for a multimedia classroom of the present invention;

FIG. 2 is a schematic structural view of a backlight module in an electronic blackboard for a multimedia classroom;

FIG. 3 is a side view of the electronic blackboard in the multimedia classroom of the present invention;

FIG. 4 is a side view of the backlight module in the electronic blackboard for multimedia classroom of the present invention;

FIG. 5 is a side view of the backlight module in the electronic blackboard for multimedia classroom of the present invention;

figure 6 is a side view of the electronic blackboard with local structure for the multimedia classroom of the utility model II.

In the above drawings: 1. a writing board; 2. an interactive plate; 3. an outer frame; 4. a movable plate; 5. a linear guide rail; 6. a movable block; 1a, a writing panel; 2a, a touch control film; 3a, a dielectric plate; 4a, a liquid crystal panel; 5a, fixing blocks; 6a, a cover plate; 6a1, raised strip; 7a, a screw; 8a, a buffer strip; 9a, a buffer layer; 10a, a backlight module; 1b, a substrate; 2b, an LED lamp strip; 2b1, LED element; 2b2, circuit board; 3b, a light guide plate; 4b, a light homogenizing film; 5b, reflective paper; 6b, supporting strips; 6b1, a first flanging part; 6b2, second flanging part; 7b, a diffusion film; 8b, a brightness enhancement film; 10b, pressing strips.

Detailed Description

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention; the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; furthermore, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, as they may be fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1: an electronic blackboard for a multimedia classroom comprises at least one writing board 1 and at least one interactive board 2, wherein the writing board 1 and the interactive board 2 are respectively installed and fixed through respective outer frame frames 3;

the interactive plate 2 comprises a writing panel 1a, a touch film 2a, a liquid crystal panel 4a and a backlight module 10a, wherein the touch film 2a is positioned between the writing panel 1a and the liquid crystal panel 4a and is pasted on one surface of the writing panel 1a, the backlight module 10a is arranged on one side, opposite to the touch film 2a, of the liquid crystal panel 4a, and a transparent dielectric plate 3a is also arranged between the touch film 2a and the liquid crystal panel 4 a;

a plurality of fixing blocks 5a are respectively arranged on the outer sides of the peripheries of the dielectric plate 3a and the liquid crystal panel 4a, the fixing blocks 5a are fixed at the edges of the peripheries of the writing panel 1a or the touch control film 2a, cover plates 6a connected with the fixing blocks 5a are respectively arranged on the outer sides of the peripheries of the dielectric plate 3a and the liquid crystal panel 4a, one side of each cover plate 6a is connected with the corresponding fixing block 5a, and the other side of each cover plate 6a is connected with the edges of the peripheries of the dielectric plate 3a and the liquid crystal panel 4a in a pressing;

a buffer strip 8a used for contacting with the side surface of the dielectric plate 3a is connected on the surface of one side of the fixed block 5a close to the dielectric plate 3a, a downward convex strip part 6a1 is arranged in the middle of the cover plate 6a positioned on the left side and the right side of the dielectric plate 3a, the convex strip part 6a1 is positioned between the fixed block 5a and the liquid crystal panel 4a and close to one end of the liquid crystal panel 4a, and buffer layers 9a are arranged between the convex strip part 6a1 and the dielectric plate 3a and between the convex strip part and the liquid crystal panel 4 a;

the backlight module 10a further comprises a substrate 1b, an LED strip 2b, a light guide plate 3b, a light-equalizing film 4b and a piece of reflective paper 5b, wherein the reflective paper 5b is located between the substrate 1b and the light guide plate 3b, the light-equalizing film 4b is located on a side surface of the light guide plate 3b opposite to the substrate 1b, and the LED strip 2b is respectively arranged on the upper side and the lower side of the light guide plate 3b and is respectively mounted on the substrate 1b through a supporting strip 6 b;

the LED lamp strip 2b comprises a plurality of LED elements 2b1 and a circuit board 2b2, the LED elements 2b1 are mounted on one side surface of the circuit board 2b2 at equal intervals, the other side surface of the circuit board 2b2 is connected with a supporting strip 6b in an adhering mode, and one side of the circuit board 2b2 on which the LED elements 2b1 are mounted is arranged in a face-to-face mode with the side surface of the light guide plate 3 b;

the movable frame further comprises at least one movable plate 4, a linear guide rail 5 and at least one movable block 6 which is distributed at intervals are arranged between the upper end face of the movable plate 4 and the upper end face of the outer frame 3, and the linear guide rail 5 is embedded into the movable block 6 or the movable block 6 is embedded into the linear guide rail 5;

the lower end of the supporting strip 6b is provided with a first flanging part 6b1 bent towards the opposite side of the light guide plate 3b, the lower surface of the first flanging part 6b1 is in contact with the surface of the substrate 1b, the first flanging part 6b1 is fixedly connected with the substrate 1b, and the supporting strip 6b is an aluminum supporting strip.

A diffusion film 7b and a brightness enhancement film 8b are stacked above the light uniformizing film 4 b; an elastic cushion layer is arranged between the lower surface of the cover plate 6a and the upper surface of the liquid crystal panel 4 a; the four cover plates 6a are respectively connected with the fixed block 5a through screws 7 a; the buffer strip 8a is a silica gel buffer strip; the buffer layer 9a is a silica gel buffer layer.

Example 2: an electronic blackboard for a multimedia classroom comprises at least one writing board 1 and at least one interactive board 2, wherein the writing board 1 and the interactive board 2 are respectively installed and fixed through respective outer frame frames 3;

the interactive plate 2 comprises a writing panel 1a, a touch film 2a, a liquid crystal panel 4a and a backlight module 10a, wherein the touch film 2a is positioned between the writing panel 1a and the liquid crystal panel 4a and is pasted on one surface of the writing panel 1a, the backlight module 10a is arranged on one side, opposite to the touch film 2a, of the liquid crystal panel 4a, and a transparent dielectric plate 3a is also arranged between the touch film 2a and the liquid crystal panel 4 a;

a plurality of fixing blocks 5a are respectively arranged on the outer sides of the peripheries of the dielectric plate 3a and the liquid crystal panel 4a, the fixing blocks 5a are fixed at the edges of the peripheries of the writing panel 1a or the touch control film 2a, cover plates 6a connected with the fixing blocks 5a are respectively arranged on the outer sides of the peripheries of the dielectric plate 3a and the liquid crystal panel 4a, one side of each cover plate 6a is connected with the corresponding fixing block 5a, and the other side of each cover plate 6a is connected with the edges of the peripheries of the dielectric plate 3a and the liquid crystal panel 4a in a pressing;

a buffer strip 8a used for contacting with the side surface of the dielectric plate 3a is connected on the surface of one side of the fixed block 5a close to the dielectric plate 3a, a downward convex strip part 6a1 is arranged in the middle of the cover plate 6a positioned on the left side and the right side of the dielectric plate 3a, the convex strip part 6a1 is positioned between the fixed block 5a and the liquid crystal panel 4a and close to one end of the liquid crystal panel 4a, and buffer layers 9a are arranged between the convex strip part 6a1 and the dielectric plate 3a and between the convex strip part and the liquid crystal panel 4 a;

the backlight module 4a further comprises a substrate 1b, an LED lamp strip 2b, a light guide plate 3b, a light homogenizing film 4b and a piece of reflective paper 5b, wherein the reflective paper 5b is positioned between the substrate 1b and the light guide plate 3b, the light homogenizing film 4b is positioned on the surface of one side of the light guide plate 3b opposite to the substrate 1b, the LED lamp strip 2b is respectively arranged on the upper side and the lower side of the light guide plate 3b, and is respectively arranged on the substrate 1b through a supporting strip 6 b;

the LED lamp strip 2b comprises a plurality of LED elements 2b1 and a circuit board 2b2, the LED elements 2b1 are mounted on one side surface of the circuit board 2b2 at equal intervals, the other side surface of the circuit board 2b2 is connected with a supporting strip 6b in an adhering mode, and one side of the circuit board 2b2 on which the LED elements 2b1 are mounted is arranged in a face-to-face mode with the side surface of the light guide plate 3 b;

the movable frame further comprises at least one movable plate 4, a linear guide rail 5 and at least one movable block 6 which is distributed at intervals are arranged between the upper end face of the movable plate 4 and the upper end face of the outer frame 3, and the linear guide rail 5 is embedded into the movable block 6 or the movable block 6 is embedded into the linear guide rail 5;

the lower end of the supporting strip 6b is provided with a first flanging part 6b1 bent towards the opposite side of the light guide plate 3b, the lower surface of the first flanging part 6b1 is in contact with the surface of the substrate 1b, the first flanging part 6b1 is fixedly connected with the substrate 1b, and the supporting strip 6b is an aluminum supporting strip.

The end of the second flanging part is provided with a second flanging part 6b2 bent towards one side of the light guide plate 3b, and the lower surface of the second flanging part 6b2 is in contact connection with the light-equalizing film 4b above the light guide plate 3 b; the left side and the right side of the light guide plate 3b are respectively provided with a pressing strip 10b, one end of the pressing strip 10b is arranged on the substrate 1b, and the other end of the pressing strip 10b is in contact connection with the light homogenizing film 4b on the light guide plate 3 b; the cross section of the pressing strip 10b is a Z-shaped cross section; the buffer strip 8a is a foam buffer strip; the cushion layer 9a is a foam cushion layer.

When the electronic blackboard for the multimedia classroom is adopted, the aluminum support bar and the first flanging part of the aluminum support bar can continuously and quickly transfer the heat of the LED lamp strip to the large-area substrate, so that the heat generated by the LED lamp strip can be quickly and uniformly radiated, the influence on the performance of other devices caused by unsmooth radiation of equipment using the backlight module, such as a touch blackboard, can be avoided, meanwhile, the use of other radiating modules can be reduced, the cost is saved, the thickness of the equipment can be reduced, and the user experience of products can be optimized; furthermore, the second flanging parts are arranged, so that the supporting strips have the function of limiting the light guide plate and the optical diaphragm at the same time, the positioning of the light guide plate and the optical diaphragm is realized under the condition of not increasing any cost, and the production efficiency is improved;

in addition, the liquid crystal panel is stripped from the traditional liquid crystal display, and is assembled into an independent module together with the writing panel and the touch film through the cover plate, and the touch and display operation can be realized by matching with the backlight module, so that the production flow is simplified, the processing is convenient, the production efficiency is greatly improved, and the production cost is saved; meanwhile, the deformation of the dielectric plate and the liquid crystal panel under the influence of environmental factors can be reduced, so that the display definition and the touch precision are improved, and the user experience is good; furthermore, the liquid crystal panel is convenient to maintain and replace, the replacement of the liquid crystal panel cannot generate adverse effects on other components such as a touch control film and the like, and the maintenance cost is reduced;

in addition, the arrangement of the buffer strips can prevent the medium plate from being in hard contact with the fixed block, protect the medium plate and provide an adaptive space for expansion with heat and contraction with cold of the medium plate under the influence of environmental factors, so that the medium plate can freely realize expansion with heat and contraction with cold without being limited by external force, thereby ensuring the stability of the physical and chemical properties of the medium plate and prolonging the service life of the medium plate;

in addition, the arrangement of the convex strip part of the cover plate can enhance the physical property and the mechanical strength of the cover plate under the condition of not increasing the thickness of the cover plate, improve the installation stability of the liquid crystal panel and the dielectric plate, play a good limiting role in the liquid crystal panel and simultaneously can not limit the free expansion and contraction of the dielectric plate.

The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose of the embodiments is to enable people skilled in the art to understand the contents of the present invention and to implement the present invention, which cannot limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered by the protection scope of the present invention.

Claims (9)

1. An electronic blackboard for a multimedia classroom is characterized in that: the writing board comprises at least one writing board (1) and at least one interactive board (2), wherein the writing board (1) and the interactive board (2) are respectively installed and fixed through respective outer frame frames (3);

the interactive plate (2) comprises a writing panel (1 a), a touch film (2 a), a liquid crystal panel (4 a) and a backlight module (10 a), wherein the touch film (2 a) is positioned between the writing panel (1 a) and the liquid crystal panel (4 a) and is pasted on one surface of the writing panel (1 a), the backlight module (10 a) is arranged on one side, opposite to the touch film (2 a), of the liquid crystal panel (4 a), and a transparent dielectric plate (3 a) is further arranged between the touch film (2 a) and the liquid crystal panel (4 a);

the periphery outer sides of the dielectric plate (3 a) and the liquid crystal panel (4 a) are respectively provided with a plurality of fixing blocks (5 a), the fixing blocks (5 a) are fixed at the periphery edges of the writing panel (1 a) or the touch control film (2 a), the periphery outer sides of the dielectric plate (3 a) and the liquid crystal panel (4 a) are respectively provided with a cover plate (6 a) connected with the fixing blocks (5 a), one side of the cover plate (6 a) is connected with the fixing blocks (5 a), and the other side of the cover plate is connected with the periphery edges of the dielectric plate (3 a) and the liquid crystal panel (4 a) in a pressing mode;

one side surface of the fixed block (5 a), which is close to the dielectric plate (3 a), is connected with a buffer strip (8 a) which is used for contacting with the side surface of the dielectric plate (3 a), the middle parts of the cover plates (6 a) positioned at the left side and the right side of the dielectric plate (3 a) are provided with a downward convex strip part (6 a 1), the convex strip part (6 a 1) is positioned between the fixed block (5 a) and the liquid crystal panel (4 a) and is close to one end of the liquid crystal panel (4 a), and buffer layers (9 a) are respectively arranged between the convex strip part (6 a 1) and the dielectric plate (3 a) and between the convex strip part and the liquid crystal panel (4 a);

the backlight module (10 a) further comprises a substrate (1 b), an LED lamp strip (2 b), a light guide plate (3 b), a light homogenizing film (4 b) and reflecting paper (5 b), wherein the reflecting paper (5 b) is positioned between the substrate (1 b) and the light guide plate (3 b), the light homogenizing film (4 b) is positioned on the surface of one side, back to the substrate (1 b), of the light guide plate (3 b), the LED lamp strip (2 b) is respectively arranged on the upper side and the lower side of the light guide plate (3 b) and is respectively installed on the substrate (1 b) through a supporting strip (6 b);

the LED lamp strip (2 b) comprises a plurality of LED elements (2 b 1) and a circuit board (2 b 2), the LED elements (2 b 1) are mounted on one side surface of the circuit board (2 b 2) at equal intervals, the other side surface of the circuit board (2 b 2) is connected with the supporting bar (6 b) in an adhering mode, and one side of the circuit board (2 b 2) provided with the LED elements (2 b 1) is arranged in a face-to-face mode with the side surface of the light guide plate (3 b);

the movable frame is characterized by further comprising at least one movable plate (4), a linear guide rail (5) and at least one movable block (6) distributed at intervals are arranged between the upper end face of the movable plate (4) and the upper end face of the outer frame (3), and the linear guide rail (5) is embedded into the movable block (6) or the movable block (6) is embedded into the linear guide rail (5);

the lower end of the supporting strip (6 b) is provided with a first flanging part (6 b 1) which is bent back to one side opposite to the light guide plate (3 b), the lower surface of the first flanging part (6 b 1) is in contact with the surface of the substrate (1 b), the first flanging part (6 b 1) is fixedly connected with the substrate (1 b), and the supporting strip (6 b) is an aluminum supporting strip.

2. The electronic blackboard for multimedia classroom according to claim 1, characterized in that: and a diffusion film (7 b) and a brightness enhancement film (8 b) are stacked above the light uniformizing film (4 b).

3. The electronic blackboard for multimedia classroom according to claim 1, characterized in that: an elastic cushion layer is arranged between the lower surface of the cover plate (6 a) and the upper surface of the liquid crystal panel (4 a).

4. The electronic blackboard for multimedia classroom according to claim 1, characterized in that: the four cover plates (6 a) are respectively connected with the fixed block (5 a) through screws (7 a).

5. The electronic blackboard for multimedia classroom according to claim 1, characterized in that: the buffer strip (8 a) is a foam buffer strip or a silica gel buffer strip.

6. The electronic blackboard for multimedia classroom according to claim 1, characterized in that: the buffer layer (9 a) is a foam buffer layer or a silica gel buffer layer.

7. The electronic blackboard for multimedia classroom according to claim 1, characterized in that: the upper end of the supporting strip (6 b) is provided with a second flanging part (6 b 2) which is bent towards one side of the light guide plate (3 b), and the lower surface of the second flanging part (6 b 2) is in contact connection with the light homogenizing film (4 b) above the light guide plate (3 b).

8. The electronic blackboard for multimedia classroom according to claim 1 or 7, characterized in that: the left side and the right side of the light guide plate (3 b) are respectively provided with a pressing strip (10 b), one end of the pressing strip (10 b) is installed on the base plate (1 b), and the other end of the pressing strip (10 b) is in contact connection with the light homogenizing film (4 b) on the light guide plate (3 b).

9. The electronic blackboard for multimedia classroom according to claim 8, characterized in that: the cross section of the pressing strip (10 b) is a Z-shaped cross section.

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