CN204215138U - A kind of teaching board book optical projection system - Google Patents

Abstract

The utility model discloses a kind of teaching board book optical projection system, comprise writing on the blackboard projection plate (1), background mechanism and projector (2), described background mechanism is positioned at the rear side of writing on the blackboard projection plate (1) and presses close to mutually with it, described writing on the blackboard projection plate (1) is made up of transparent material, described background mechanism comprises fixed black background board (3) and projection screen plate (4), described projection screen plate (4) is positioned between fixed black background board (3) and writing on the blackboard projection plate (1), projection screen plate (4) is electrically-controlled liquid crystal photo chromic glass, electrically-controlled liquid crystal photo chromic glass is transparent shape when being energized, then in white during power-off, described projector (2) is projected on the electrically-controlled liquid crystal photo chromic glass of power-off when projecting.The utility model can increase effective write area, can change the position of electrically-controlled liquid crystal photo chromic glass or outage area to change projected position, make the content seeing projection per capita clearly of different angles.

Description

A blackboard projection system for teaching

technical field

The utility model relates to the field of teaching appliances, in particular to a blackboard projection system for teaching.

Background technique

The blackboard used for teaching blackboard writing is indispensable in the classroom. For modern teaching, multimedia projection is naturally indispensable. Many classrooms use teaching equipment combining blackboards and projection screens, which not only meet the needs of teachers for blackboard writing, but also use projection equipment for projection teaching. In the prior art, the projection equipment includes a projector and a projection screen. The projection screen and the blackboard are generally installed on the wall in front of the classroom. However, due to the limited area of the wall, the projection screen and the blackboard often overlap. Therefore, there are following technical problems in the blackboard projection equipment of the prior art:

1. The overlapping part of the projection screen and the blackboard will cover part of the blackboard, and some projection screens even cover almost half of the blackboard, which greatly reduces the effective writing area of the blackboard;

2. The installation position of the projection screen in the prior art is fixed. If the projection screen is set on the left side of the classroom, the students on the right side will be affected. Similarly, if the projection screen is set on the right side of the classroom, the students on the left side will be affected. will be affected to a certain extent. If the projection screen is set in the middle of the classroom, it will not only affect the viewing of students on both sides, but also affect the teacher's writing on the blackboard;

3. In order to increase the effective writing area of the blackboard, it is necessary to turn off the projector in the middle of the class, raise the projection screen, and then lower the projection again, which is not only troublesome, but also a waste of class time;

4. After writing on the entire blackboard, if you need the assistance of a multimedia projector, the projection screen will cover part of the chalk writing on the blackboard at this time, causing some inconvenience. If you want to use these chalk writing again, you need to turn off the projector. The projection screen rises.

Utility model content

In view of this, the utility model provides a blackboard writing projection system for teaching with large effective writing area and adjustable projection position, aiming at the problems in the prior art that the blackboard overlaps with the projection screen to reduce the effective writing area.

The technical solution of the utility model is to provide a blackboard projection system for teaching with the following structure, including a blackboard projection board, a background mechanism and a projector. The background mechanism is located at the back side of the blackboard projection board and is close to it, so The blackboard projection board is made of transparent material. The background mechanism includes a fixed black background board and a projection screen. The projection screen is located between the black background board and the blackboard projection board. The projection screen is an electronically controlled liquid crystal color changer. Glass, the electronically controlled liquid crystal color-changing glass is transparent when the power is turned on, and is white when the power is cut off, and the projector projects on the electrically controlled liquid crystal color-changing glass when the power is cut off.

With the above structure, compared with the prior art, the utility model has the following advantages: with the utility model, since the background mechanism is close to the blackboard writing projection board made of transparent material, the black background board is fixed as the background when the writing on the blackboard is used, In the corresponding area of the blackboard projection board, the black background allows the listeners to see the content of the blackboard writing clearly, while the electronically controlled liquid crystal color-changing glass is white when the power is off, and it is used as the background for projection. When projected onto this area, it can be clearly To display the projected content, when there is no need to project, it is powered on to make it transparent. At this time, the fixed black background board behind it is all used as the background of the blackboard projection board. The utility model can increase the effective writing area, and can change the position of the electronically controlled liquid crystal color-changing glass or the power-off area to change the projection position, so that people from different angles can clearly see the projected content.

Preferably, the area of the projection screen corresponds to the projection range of the projector, and the projection screen can slide left and right under the drive of the drive mechanism to change the projection position, and the projector also changes the projection direction accordingly, so that the projection range is relatively large. Electronically controlled liquid crystal color-changing glass in quasi-power-off state. By adjusting the position of the projection screen, an appropriate projection position can be selected to meet the needs of use.

Preferably, the drive mechanism includes a screw motor and a screw, the output shaft of the screw motor is connected to the screw, the projection screen is sleeved on the screw, and the screw motor rotates to drive the projection screen The board moves. Through the screw motor and the screw rod, the rotation of the motor is converted into the movement of the projection screen panel, which facilitates the position adjustment of the projection screen panel.

Preferably, the projector is installed on the sliding guide rail. When adjusting the projection position, the screw motor drives the projection screen to slide, and at the same time, the projector slides on the sliding guide rail to keep the projector projected on the projection screen at all times. It is convenient to adjust the projection position as needed.

Preferably, a photosensitive element is provided on the projection screen, a laser source matched with the photosensitive element is provided on the projector, and the photosensitive element is electrically connected to the screw motor and the electronically controlled liquid crystal color-changing glass respectively. When adjusting the projection position, the projector slides along the sliding guide rail, the laser source touches the photosensitive element, and the photosensitive element controls the movement of the screw motor to keep the laser source aligned with the photosensitive element.

As a preference, the electronically controlled liquid crystal color-changing glass is formed by connecting multiple liquid crystal color-changing glass plates, each liquid crystal color-changing glass plate is powered by a corresponding circuit, and the corresponding liquid crystal color-changing glass plate at the projection position is powered off to form a projection area , the projector projects on the projection area. Select the projection position as required, and cut off the power of the liquid crystal color-changing glass plate corresponding to the projection position to form a white projection area, which is convenient for the adjustment and transformation of the projection position.

Preferably, the plurality of liquid crystal color-changing glass plates are provided with photosensitive elements, the projector is provided with a laser source matched with the photosensitive elements, and the photosensitive elements are connected to the power supply circuit of the corresponding liquid crystal color-changing glass plates . When adjusting the projection position, the projector slides along the sliding guide rail, and the laser source touches the corresponding photosensitive element of the liquid crystal color-changing glass plate, and then several liquid crystal color-changing glass plates near the liquid crystal color-changing glass plate are powered off to form a new projection area.

Preferably, a lens cover is provided on the projection lens of the projector, and when the projection is paused or terminated, the lens cover is used to block the projection lens, the laser source touches the photosensitive element, and the photosensitive element controls the energization of the electrically controlled liquid crystal color-changing glass that is powered off. In this way, the annoyance of retracting and placing the projection screen in the prior art is avoided, and the original projection area becomes an area where blackboard writing can be written, effectively utilizing the writing area of the blackboard projection board.

Preferably, when the projection is started or continued, the lens cover is opened, the photosensitive element is touched by the laser source, and the photosensitive element controls the power-off of the corresponding projection area of the electronically controlled liquid crystal color-changing glass. It is convenient to switch between suspending projection and continuing projection.

Preferably, the transparent material used to make the blackboard projection board can realize diffuse reflection of light. So that audiences from different angles can see clearly the contents of the writing on the blackboard and the projection.

Description of drawings

Fig. 1 is the structural representation (first state) of embodiment 1;

Fig. 2 is the structural representation (second state) of embodiment 1;

Fig. 3 is the structural representation (first state) of embodiment 2;

Fig. 4 is the structural representation (second state) of embodiment 2;

Fig. 5 is a structural schematic diagram of a projector and a sliding guide rail;

As shown in the figure, 1. blackboard projection board, 2. projector, 2.1. projection lens, 2.2. lens cover, 3. fixed black background board, 4. projection screen board, 4.1. screw rod, 4.2. liquid crystal color-changing glass plate , 5, sliding guide rail, 6, photosensitive element, 7, laser source.

Detailed ways

The utility model will be further described below in conjunction with the accompanying drawings and specific embodiments, but the utility model is not limited to these embodiments.

The utility model covers any replacement, modification, equivalent method and scheme made on the spirit and scope of the utility model. In order to make the public have a thorough understanding of the utility model, specific details are described in the following preferred embodiments of the utility model, and those skilled in the art can fully understand the utility model without the description of these details. In addition, for the purpose of illustration, the drawings of the present utility model are not completely drawn in accordance with the actual scale, and are described here.

As shown in Fig. 1, 2 and 5, a kind of blackboard projection system for teaching of the present utility model comprises blackboard projection board 1, background mechanism and projector 2, and described background mechanism is positioned at the rear side of blackboard projection board 1 and with it Close to each other, the blackboard projection board 1 is made of transparent material, the background mechanism includes a fixed black background board 3 and a projection screen 4, and the projection screen 4 is located between the fixed black background board 3 and the blackboard projection board 1 Among them, the projection screen 4 is an electronically controlled liquid crystal color-changing glass. The electronically controlled liquid crystal color-changing glass is transparent when it is powered on, and white when it is powered off. on the color changing glass.

It should be noted that the "transparency" of "the blackboard writing projection board 1 is made of transparent material" is not absolutely transparent, including semi-transparent and other states. The transparency is set based on the requirement that the audience can see the characters clearly, for example, in After frosting, its transparency will be reduced, and the diffuse reflection after frosting can make the human eye see more clearly.

Electronically controlled liquid crystal color-changing glass is also called electronically controlled dimming glass. It is a high-tech photoelectric glass product made of liquid crystal film through high temperature and high pressure, interlayer packaging. Users can control the arrangement of liquid crystal molecules by whether the current is energized or not. So as to achieve the ultimate goal of controlling the transparent and opaque state of the glass. The liquid crystal molecules are arranged in a straight line when the power is on, and the liquid crystal glass is light-transmitting and transparent; when the power is off, the liquid crystal molecules are scattered and white, and the liquid crystal film is light-transmitting but opaque.

The utility model lists two embodiments, as shown in Figures 1 and 2, which illustrate the structure of Embodiment 1. Figure 1 shows the projection screen panel in the power-off projection state, and Figure 2 shows the projection screen panel in the power-on transparent state. The area of the projection screen 4 corresponds to the projection range of the projector 2, the projection screen 4 can slide left and right under the drive of the drive mechanism to change the projection position, and the projector 2 also changes the projection direction accordingly, so that the projection range Align the electronically controlled liquid crystal color-changing glass in the power-off state.

The drive mechanism includes a screw motor (for clarity of illustration, the screw motor is not shown in the figure) and a screw 4.1, the output shaft of the screw motor is connected to the screw 4.1, and the projection screen 4 Sleeved on the screw rod 4.1, the screw motor rotates to drive the projection screen panel 4 to move.

The projector 2 is installed on the sliding guide rail 5. When adjusting the projection position, the screw motor drives the projection screen 4 to slide, and the projector 2 slides on the sliding guide rail 5 at the same time, so that the projector 2 is always projected on the projection screen 4 . The projector 2 slides on the sliding guide rail 5 under the drive of the stepping motor.

The projection screen 4 is provided with a photosensitive element 6, and the projector 2 is provided with a laser source 7 matched with the photosensitive element 6, and the described photosensitive element 6 is connected with the screw motor and the electronically controlled liquid crystal color-changing glass electrical connection. When adjusting the projection position, the projector slides along the sliding guide rail, the laser source touches the photosensitive element, and the photosensitive element controls the movement of the screw motor to keep the laser source aligned with the photosensitive element.

As shown in Figures 3 and 4, the structure of Embodiment 2 is schematically illustrated. Figure 3 shows the projection screen panel in the power-off projection state, and Figure 4 shows the projection screen panel in the power-on transparent state. The difference between embodiment 2 and embodiment 1 is that in embodiment 2, when changing the projection position, there is no need to move the projection screen, but the adjustment of the projection position is realized by turning on and off the area. Embodiment 1 may consist of only one piece of electronically controlled liquid crystal color-changing glass equivalent to the projection range, while Embodiment 2 consists of multiple liquid crystal color-changing glass plates, and the combined area is equivalent to that of blackboard projection boards and fixed black background boards. The concrete structure of embodiment 2 is as follows:

The electronically controlled liquid crystal color-changing glass is formed by connecting a plurality of liquid crystal color-changing glass plates 4.2, and each liquid crystal color-changing glass plate 4.2 is powered by a corresponding circuit, and the corresponding liquid crystal color-changing glass plate 4.2 at the projection position is powered off to form a projection area , the projector 2 projects on the projection area.

The plurality of liquid crystal color-changing glass plates 4.2 are provided with photosensitive elements 6 (can be arranged in one-to-one correspondence, and can also be selectively arranged), and the described projector 2 is provided with a laser source that matches the photosensitive elements 6 7. The photosensitive element 6 is connected to the power supply circuit corresponding to the liquid crystal color-changing glass plate 4.2. When adjusting the projection position, the projector slides along the sliding guide rail, and the laser source touches the corresponding photosensitive element of the liquid crystal color-changing glass plate, then several liquid crystal color-changing glass plates near the liquid crystal color-changing glass plate are powered off (the liquid crystal color-changing glass aligned with the laser source glass plate as the center), forming a new projection area.

As shown in Figure 5, Embodiment 1 and 2 also have other common technical characteristics: the projection lens of projector 2 is provided with lens cover 2.1, when suspending projection or finishing projection, block projection lens with lens cover 2.1, laser source 7. Touch the photosensitive element 6, and the photosensitive element 6 controls the energization of the electrically controlled liquid crystal color-changing glass that is powered off;

When starting to project or continue to project, open the lens cover 2.1, the photosensitive element 6 is touched by the laser source 7, and the photosensitive element 6 controls the power-off of the corresponding projection area of the electronically controlled liquid crystal color-changing glass.

The transparent material used to make the blackboard projection board 1 can realize diffuse reflection of light.

"The lens cover blocks the projection lens" is only for the convenience of use in the classroom or teaching process, and does not turn off the power of the projector. After the end, the power of the projector needs to be turned off.

Since the color of the white chalk characters on the blackboard projection board is white, which is consistent with the white background, the white chalk anywhere on the blackboard projection board will not affect the projection effect, that is, it is not necessary to erase the white chalk characters in the projection area during projection. After the projection disappears, the white chalk characters can continue to be used.

The utility model also has the advantages that the prior art does not have: the use of frosted glass or frosted plexiglass does not affect the writing effect of chalk in a wet state, so a wet towel can be used as a blackboard eraser, which avoids the impact of dust on the user's lungs. infringement.

The above is only a description of the preferred embodiments of the present utility model, but should not be construed as a limitation on the claims. The utility model is not limited to the above embodiments, and its specific structure allows changes. In a word, all the various changes made within the scope of protection of the independent claims of the utility model are within the scope of protection of the utility model.

Claims (10)

1. A blackboard projection system for teaching, characterized in that: comprise blackboard projection board (1), background mechanism and projector (2), described background mechanism is positioned at the rear side of blackboard projection board (1) and close to it , the blackboard projection board (1) is made of transparent material, the background mechanism includes a fixed black background board (3) and a projection screen board (4), and the projection screen board (4) is located on the fixed black background board (3) between blackboard projection board (1), projection screen board (4) is electric control liquid crystal color-changing glass, and electric control liquid crystal color-changing glass is transparent when power-on, and then is white when power-off, described projector ( 2) When projecting, it is projected on the electrically controlled liquid crystal color-changing glass that is powered off. 2. The blackboard projection system for teaching according to claim 1, characterized in that: the area of the projection screen (4) is corresponding to the projection range of the projector (2), and the projection screen (4) is driving Driven by the mechanism, it can slide left and right to change the projection position, and the projector (2) also changes the projection direction thereupon, so that the projection range is aligned with the electronically controlled liquid crystal color-changing glass in the power-off state. 3. The blackboard projection system for teaching according to claim 2, characterized in that: the drive mechanism comprises a screw motor and a screw (4.1), and the output shaft of the screw motor is connected to the screw (4.1) , the projection screen panel (4) is sheathed on the screw rod (4.1), and the screw motor rotates to drive the projection screen panel (4) to move. 4. The blackboard projection system for teaching according to claim 3, characterized in that: the projector (2) is installed on the sliding guide rail (5), and when the projection position is adjusted, the screw motor drives the projection screen (4 ) slides, while the projector (2) slides on the sliding guide rail (5), keeping the projector (2) projected on the projection screen (4) all the time. 5. The blackboard projection system for teaching according to claim 2, characterized in that: the projection screen (4) is provided with a photosensitive element (6), and the described projector (2) is provided with a photosensitive element (6) A matched laser source (7), the photosensitive element (6) is electrically connected to the screw motor and the electronically controlled liquid crystal color-changing glass respectively. 6. The blackboard projection system for teaching according to claim 1, characterized in that: the electronically controlled liquid crystal color-changing glass is formed by connecting a plurality of liquid crystal color-changing glass plates (4.2), and each liquid crystal color-changing glass plate (4.2) All are powered by corresponding circuits, and the corresponding liquid crystal color-changing glass plate (4.2) at the projection position is powered off to form a projection area, and the projector (2) is projected on the projection area. 7. The blackboard projection system for teaching according to claim 6, characterized in that: said plurality of liquid crystal color-changing glass plates (4.2) are provided with photosensitive elements (6), and said projector (2) is provided with There is a laser source (7) matched with the photosensitive element (6), and the photosensitive element (6) is connected to the power supply circuit of its corresponding liquid crystal color-changing glass plate (4.2). 8. The blackboard writing projection system for teaching according to claim 1, 2 or 6, characterized in that: a lens cover (2.1) is provided on the projection lens of the projector (2), and when the projection is suspended or terminated, the lens is used to The cover (2.1) blocks the projection lens, the laser source (7) touches the photosensitive element (6), and the photosensitive element (6) controls the energization of the electrically controlled liquid crystal color-changing glass that is powered off. 9. The blackboard writing projection system for teaching according to claim 1, 2 or 6, characterized in that: when starting or continuing to project, the lens cover (2.1) is opened, and the photosensitive element (6) is touched by the laser source (7) , the photosensitive element (6) controls the power-off of the corresponding projection area of the electronically controlled liquid crystal color-changing glass. 10. The blackboard writing projection system for teaching according to claim 1, 2 or 6, characterized in that: the transparent material made of the blackboard writing projection board (1) can realize diffuse reflection of light.