CN111161608A - Portable color shadow demonstration device - Google Patents

Abstract

The invention provides a portable color shadow demonstration device, which comprises a base support, a universal converter and three LED projection lamps, wherein the LED projection lamps are fixed on the base support by utilizing the universal converter, and the angles and the heights of the projection lamps are adjusted at will; the projection lamp is powered by using a mobile power supply; three projection lamps are arranged according to a certain position and then projected onto a screen; by means of a certain placement portable color shadow demonstration device, a person can observe a color shadow when standing between an LED projection lamp and a screen; the demonstration device has strong interactivity, interestingness and portability, is suitable for being displayed in classroom environments of schools or large places such as exhibition halls, science and technology halls, and has a good popular science effect.

Description

Portable color shadow demonstration device

Technical Field

The invention belongs to the field of manufacturing of demonstration physical instruments, and particularly relates to a portable color shadow demonstration device which generates colorful shadows by utilizing the principle of three primary colors of light.

Background

Red, green and blue are three basic colors which can not be decomposed in nature, and most colors in nature can be obtained by mixing three primary colors according to a certain proportion, and vice versa. In general, when an object is illuminated with white light, a black shadow is visible on the back of the object. This is because the light projected onto the object is blocked by the object. According to the three primary color principle, if we use several different colored light sources to illuminate the object at different angles, different colored (colored) shadows will be produced.

The existing device for demonstrating color shadows basically utilizes projection lamps with three primary colors and is respectively fixed on the top of a roof. The three lamps are distributed in an equilateral triangle shape, project on the screen and are focused into one point. When no object is between the projector and the screen, the light spot on the screen is white. When the audience station projects light and the screen, the shadow on the screen is not black any more due to shielding part of the light of the projecting light, thereby generating a color shadow effect. The projection lamp with the design can not move usually, the distance between the projection lamps is not adjustable, and the influence of the position and the angle of the projection lamp on the color shadow is inconvenient to demonstrate and the interaction effect is poor. In addition, with the progress of global science popularization work, the portability of science popularization demonstration instruments becomes an important factor, and if the science popularization instruments which can be conveniently carried can be manufactured, the science popularization instruments have great help for developing outdoor science popularization activities, teaching activities and the like. Therefore, it is desirable to design a color shadow demonstration device with portability and interactivity.

Disclosure of Invention

In order to solve the problems of the prior art, the applicant provides a portable color shadow demonstration device.

According to the technical scheme, the portable color shadow demonstration device comprises a base support, a universal converter and three LED projection lamps, wherein the LED projection lamps are fixed on the base support by utilizing the universal converter, and the angles and the heights of the projection lamps are adjusted at will; the projection lamp is powered by using a mobile power supply; three projection lamps are arranged according to a certain position and then projected on a screen.

Further, portable colored shadow presentation device includes 3 base supports, 3 universal converters, 1 red LED profection lamp, 1 green LED profection lamp, 1 blue LED profection lamp, 3 lithium electricity batteries and 1 face screen, wherein the base support is used for supporting and hangs the LED profection lamp, universal converter one end is fixed on the base support, the LED profection lamp is fixed to universal converter's the other end, lithium electricity batteries is used for supplying power for the LED profection lamp, the screen is used for showing colored shadow figure.

The base support comprises an aluminum alloy section and a counterweight cast iron base, the aluminum alloy section and the counterweight cast iron base are connected together through screws, and the aluminum alloy section is vertically fixed on the counterweight cast iron base.

Further, the length of the aluminum alloy section in the base support is 2 meters, and the section size is 10cm multiplied by 10 cm. The counter weight base is square cast iron base, prevents that the aluminum alloy pole from empting, and the base size is 0.4 meter, weight 5 Kg. Both are secured with M6 screws.

Furthermore, the universal converter consists of a square aluminum tube, an aluminum rod, a concave aluminum tube and a circular aluminum tube. Wherein, the inner diameter of the square aluminum pipe is 10cm multiplied by 10cm, the wall thickness is 4mm, and M6 internal threads are drilled on two adjacent sides. The diameter of the aluminum bar is 6mm, the length of the aluminum bar is 2cm, and an M6 external thread is arranged at one end of the aluminum bar. The aluminum bar and one of the internal threads of the square aluminum tube are connected together. An M6 screw was screwed into another internal thread of the square aluminum tube to be fixed to the base bracket. The concave aluminum tube has the inner diameter of 6mm, the length of 2cm and the depth of 1.5cm, M4 internal threads are drilled on the side surface and the bottom, and the concave aluminum tube is fixed on an aluminum bar by using M4 screws and the internal threads on the side surface. The inner diameter of the round aluminum pipe is 5cm, and the length of the round aluminum pipe is 5 cm. A round hole with the diameter of 4mm is drilled in the middle of the side surface, and M4 internal threads are drilled on the other side surface. The aluminium and female aluminium tubes were secured together by means of a 4mm circular hole using an M4 screw. The LED projector is fixed by screwing an M4 screw on the internal thread of the side surface.

Preferably, the LED projection lamp is a single-color LED diffusion light source which can respectively emit red, green and blue lights. The diameter of the lamp tube is 5cm, and the power supply voltage is 5V. And is fixed on an aluminum pipe of the universal converter through an M4 screw.

Furthermore, the lithium battery is a rechargeable mobile power supply, the capacity of the rechargeable mobile power supply is 20000mAh, and the voltage of the rechargeable mobile power supply is 5V. And the LED projection lamp is connected with the USB wire. Because the portable power source is provided with the power switch, the LED projection lamp can be controlled to be turned on or off by switching on or off the switch of the portable power source. The lithium battery is fixed on the counterweight base in the base support through acrylic acid structural adhesive.

Further, the screen can be a vertical type white glass fiber plastic screen or a clean white wall for projection.

Compared with the prior art, the device provided by the invention can be used for demonstrating the three-primary-color superposition principle and also can demonstrate the color shadow phenomenon by switching on and off the three LED projection lamps. The object that the people used as sheltering from the light source has increased the interactive and playability, interesting and maneuverability of demonstration, can demonstrate in large-scale places such as school classroom environment or exhibition hall, science and technology museum. In addition, the invention realizes the interactivity and the portability of the color shadow demonstration instrument through the movable LED projection lamp, and can well show the optical principle of three primary colors and the application thereof. Has better promoting effect on the development of global science popularization.

Drawings

FIG. 1 is a schematic perspective view of a portable color shadow demonstration apparatus according to the present invention.

Fig. 2 is a perspective view of a universal converter used in the demonstration apparatus shown in fig. 1.

Fig. 3 is a schematic view of the presentation apparatus shown in fig. 1 illustrating the principle of three primary colors.

FIG. 4 is a schematic diagram of a typical placement of the color shadow by the presentation apparatus of FIG. 1.

Fig. 5 is a schematic diagram showing the placement of the LED projector when the positions of the LED projector coincide with each other in the case of demonstrating color shadows by the demonstration apparatus shown in fig. 1.

FIG. 6 is a schematic view of the presentation apparatus of FIG. 1 showing the appearance of color outlines and black shadows.

Fig. 7 is a schematic view of the presentation device of fig. 1 in a color profile.

Fig. 8 is a schematic view of the arrangement of the color profiles shown in fig. 5.

FIG. 9 is a schematic illustration of the presentation apparatus of FIG. 1 showing the critical condition of color shadows.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the apparatus of the present invention. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. Additionally, the scope of the present invention should not be limited to the particular structures or components or the particular parameters described below.

FIG. 1 is a schematic three-dimensional structure of a portable color shadow demonstration apparatus according to the present invention; FIG. 2 is a schematic diagram of a gimbal converter of the presentation apparatus shown in FIG. 1; fig. 3 is a schematic view of a component arrangement structure and an effect diagram of the present invention.

Description of reference numerals: 101 is a base support, 102 is an aluminum alloy section bar, 103 is a universal converter, 104 is a red LED projection lamp, 105 is a green LED projection lamp, 106 is a blue LED projection lamp, 107 is a rechargeable mobile power supply, 108 is a rechargeable mobile power supply switch, 109 is a USB power supply line, 110 is a general shielding object or a person, 111 is a screen or a white wall, and 112 is a color shadow. 201 is a square aluminum tube, 202 is M6 internal threads on the square aluminum tube, 203 is an M6 screw, 204 is an aluminum rod, 205 is a concave aluminum tube, 206 is an M4 screw, 207 is an M4 internal thread, 208 is a circular aluminum tube, and 209 is a 4mm round hole on the circular aluminum tube.

The portable color shadow demonstration device comprises a base support 3, universal converters 3, 1 red LED projection lamp 104, 1 green LED projection lamp 105, 1 blue LED projection lamp 106, a mobile power supply 3 and a screen 1. The portable color shadow demonstration device of the invention utilizes the universal converter to fix the LED projection lamp on the base bracket, randomly adjusts the angle and the height of the projection lamp, and utilizes the mobile power supply to supply power to the projection lamp; three projection lamps are arranged according to a certain position and then projected on a screen. The base support is preferably cast iron counterweight base support, the screen is preferably a white wall, and the mobile power supply is preferably a lithium battery. The screen can be selected from a vertical type white glass fiber plastic screen.

Further, in the portable color shadow demonstration device of the invention, the base bracket is fixed on a counterweight cast iron base by an aluminum alloy section bar through screws. One end of the universal converter is fixed on the aluminum alloy section, the other end of the universal converter is connected with the LED projection lamp, and the height and the angle of the projection lamp can be adjusted at will by utilizing the universal converter. The LED projection lamp is a monochromatic LED light source and can emit red, green and blue lights respectively. The lithium battery can be used for supplying power to the LED projection lamp. The device is assembled into a light source projection system, and three light sources are arranged according to a certain angle and then projected onto a screen.

Further, the length of the aluminum alloy section in the base support is 2 meters, and the section size is 10cm multiplied by 10 cm. The counter weight base is square cast iron base, prevents that the aluminum alloy pole from empting, and the base size is 0.4 meter, weight 5 Kg. Both are secured with M6 screws.

Furthermore, the universal converter consists of a square aluminum tube, an aluminum rod, a concave aluminum tube and a circular aluminum tube. Wherein, the inner diameter of the square aluminum pipe is 10cm multiplied by 10cm, the wall thickness is 4mm, and M6 internal threads are drilled on two adjacent sides. The diameter of the aluminum bar is 6mm, the length of the aluminum bar is 2cm, and an M6 external thread is arranged at one end of the aluminum bar. The aluminum bar and one of the internal threads of the square aluminum tube are connected together. An M6 screw was screwed into another internal thread of the square aluminum tube to be fixed to the base bracket. The concave aluminum tube has the inner diameter of 6mm, the length of 2cm and the depth of 1.5cm, M4 internal threads are drilled on the side surface and the bottom, and the concave aluminum tube is fixed on an aluminum bar by using M4 screws and the internal threads on the side surface. The inner diameter of the round aluminum pipe is 5cm, and the length of the round aluminum pipe is 5 cm. A round hole with the diameter of 4mm is drilled in the middle of the side surface, and M4 internal threads are drilled on the other side surface. The aluminium and female aluminium tubes were secured together by means of a 4mm circular hole using an M4 screw. The LED projector is fixed by screwing an M4 screw on the internal thread of the side surface.

Further, the LED projection lamp is a single-color LED diffusion light source which can respectively emit red, green and blue lights. The diameter of the lamp tube is 5cm, and the power supply voltage is 5V. And is fixed on an aluminum pipe of the universal converter through an M4 screw.

Furthermore, the lithium battery is a rechargeable mobile power supply, the capacity of the rechargeable mobile power supply is 20000mAh, and the voltage of the rechargeable mobile power supply is 5V. And the LED projection lamp is connected with the USB wire. Because the portable power source is provided with the power switch, the LED projection lamp can be controlled to be turned on or off by switching on or off the switch of the portable power source. The lithium battery is fixed on the counterweight base in the base support through acrylic acid structural adhesive.

The steps of assembling the portable color shadow demonstration device of the invention are as follows:

first, the weighted cast iron base 101 and the aluminum alloy profile 102 were connected together using M6 screws.

Then, the gimbal converter 103 is assembled: screwing one end of an aluminum rod 204 with threads into an M6 internal thread 203 on the square aluminum pipe 201 to fix the aluminum rod; sleeving a square aluminum pipe 202 on the aluminum alloy section 102, and screwing an M6 screw on the square aluminum pipe 203 to fix the square aluminum pipe on the aluminum alloy section; the concave aluminum tube 205 is sleeved on the aluminum rod 204 and fixed by an M4 screw 206; a round aluminum tube was screwed through a 4mm round hole 209 in the round aluminum tube 208 using M4 screws and secured to the M4 internal threads 207 in the female aluminum tube.

Next, the LED projectors (red LED projector 104, green LED projector 105, and blue LED projector 106) are fixed to a circular aluminum pipe 208 and fixed by M4 screws 206. The universal converter combined in this way can change the height of the LED projector by adjusting the height of the square aluminum pipe 201 on the aluminum alloy section bar 102, and can change the level of the LED projector by adjusting the angle of the concave aluminum pipe 205.

Then, the rechargeable mobile power supply 107 is fixed on a counterweight base in the base bracket by acrylic structural adhesive, one end of the USB power supply line 109 is connected with a USB port of the mobile power supply output port, and the other end is connected to the LED projection lamp (104, 105, 106). The turning on and off of the LED projection lamp can be realized by switching on and off the mobile power switch 108.

Finally, the components are arranged according to the schematic diagram of the arrangement structure of the components shown in FIG. 3. The three LED projection lamps (red LED projection lamp 104, green LED projection lamp 105, blue LED projection lamp 106) are arranged in a symmetrical distribution, wherein the red LED projection lamp 104 is arranged on the left side, the green LED projection lamp 105 is arranged in the middle, and the blue LED projection lamp 106 is arranged on the right side. And ensures that the projection on the screen (or white wall) 110 has a symmetric white light overlap region.

The portable color shadow demonstration device of the invention is used for demonstrating the principle of three primary colors:

the principle of light three primary colors is as follows: when the three primary colors of red, green and blue are used for superposition, other colors can be generated and the rule of "additive method" is followed. That is, red mixed with green may produce yellow, green mixed with blue may produce cyan, and blue mixed with red may produce violet or magenta. When these three primary colors are superimposed together in equal proportion, they become gray; if the intensities of the three primary colors are adjusted to be maximum and overlapped by equal amount, white will appear.

The method comprises the following steps: three LED projection lamps (a red LED projection lamp 104, a green LED projection lamp 105 and a blue LED projection lamp 106) are arranged according to the positions shown in FIG. 3, no special requirements are required for the distance between the projection lamps and the screen 111 (which is obviously improved compared with the technical specification strictly required by the projection lamps in the prior art), and for convenience of observation, the distance between the projection lamps is generally recommended to be 0.5 meter, the height is generally recommended to be 1.5 meters, and the distance between the middle projection lamp and the screen is generally recommended to be 3 meters. The power switch 108 of each projector is turned on, and the angle and height of each projector are adjusted, so that the light spot of each projector on the screen is as shown in fig. 3.

According to the principle of light tri-color, 7 colors will appear in the projected area as shown in fig. 3.

The portable color shadow demonstration device of the invention is used for demonstrating color shadows:

the principle is as follows: the LED projection lamp and the shielding object are placed according to the placement diagram shown in fig. 4, and in general, any one LED projection lamp will form a black area after passing through the shielding object. For example, when the red LED projector 106 passes through the barrier 109, three sections of regions are formed on the screen 110, as indicated by the reference numeral 401, wherein the "F" region is black and the remaining ends are red. Since the green and blue LED projection lamps are also turned on at the same time and are not black in the 'F' region, the color of the 'F' region is the superposition of green and blue, and the shadow formed according to the light three primary color principle is cyan. In the same way, the red and blue LED projection lamps form three color regions on the screen 110 as shown by marks 402 and 403, and form shadows corresponding to the obstacles in both the "D" region and the "B" region.

In order to further describe the influence of the position relationship among the LED projection lamp, the shielding object and the screen on forming the color shadow, the distance between the adjacent LED projection lamps is recorded as a, the distance between the LED projection lamp and the shielding object is recorded as b, the distance between the shielding object and the screen is recorded as c, and the width of the shielding object is recorded as 2 d. Note that when the red LED projector 106 passes through the barrier 109, the boundaries of the shadows formed on the screen 110 are R1 and R2, the red LED projector corresponds to G1 and G2, and the blue LED projector corresponds to B1 and B2. It is clear that B1 and R2, B2 and R1 are point symmetric about the middle O.

As shown in fig. 5, when three lamps of red, green and blue are overlapped, that is, when the distance a =0 between the adjacent LED projectors, B1 and R1 are overlapped, the respective LED projectors form projection areas as shown by 501, 502 and 503, the overlapped projection is shown by 504, at this time, only one shadow is formed and is black, the "B" area as shown by 504, and the non-shadow area is white, and the "a" and "C" areas as shown by 504.

As shown in FIG. 6, as the distance a between adjacent LED projectors gradually increases, the LED projectors form projection areas as shown at 601, 602, and 603, and the superimposed projection is shown at 604. It can be seen that the black shadow 604 "D" segment gradually decreases and the edges appear to have 4 color profiles, yellow, red, blue, cyan, respectively, as shown at 604 "B, C, E, F". However, in this case, the color profile formed is not a true shadow of the mask.

As shown in fig. 7, when the distance a between the adjacent LED projectors is gradually increased and the projection satisfies the coincidence of B2 and R1, the respective LED projectors form projection regions as shown by 701, 702, and 703, and the superimposed projection is as shown by 704. It can be seen that the shadow of black disappears and only the color outline of the shield on the screen, as shown at 704 "B, C, E, F" has 4 colors, yellow, red, blue, cyan, respectively. This is a critical condition for disappearance of the black shadow, and as can be seen from the geometric relationship of the respective components, d/a = c/(b + c) is satisfied.

As shown in fig. 8, the distance a between adjacent LED projectors is increased, and the LED projectors form projection areas as shown in 801, 802 and 803, and the superimposed projection is shown in 804. It can be seen that at this point the shade of the shade becomes progressively sharper and can be formed in 5 colours, yellow, red, magenta, blue, cyan respectively as indicated at 804 "B, C, E, F".

As shown in fig. 9, when the distance a between the adjacent LED projectors is increased, and R1 and G2 or B2 and G1 are overlapped, the respective LED projectors form projection areas as 801, 802, and 803, and the projection after the overlapping is as 804. It can be seen that the three shadows are independent of each other, as indicated at 704 "B, C, E, F", and are 3 colors, yellow, magenta, and cyan, respectively. At this time, as a critical condition for forming an independent color shadow, it can be proved that: ac =2d (b + c).

As shown in FIG. 4, as the distance a between adjacent LED projectors is gradually increased, the LED projectors form projection areas as shown by 401, 402 and 403, and the superimposed projection is shown as 404. It can be seen that the color shadows formed by the three LED projectors are gradually separated, the colors being consistent with fig. 9, and there are white light regions between each color shadow, as shown at 404 "C, E".

The above-mentioned changes are only the changes in the distance a between the LED projectors. Of course, changing the distance b between the LED projector and the shield, or the distance c between the shield and the screen, or the width 2d of the shield can change the projected color change while keeping the distance a between adjacent LED projectors unchanged. The change in shadow occurs as long as the critical geometric relationship described above is satisfied.

Further, a method for using the color shadow for demonstration is provided.

The use method I comprises the following steps: and demonstrating the color shadow outline.

If the barrier is a senior man, typically 2d =0.44 meters, the man is a distance b =1.5 meters from the middle green LED projector, and a distance c =2 meters from the screen, the distance a =0.385 meters between adjacent LED projectors can be obtained according to the geometric critical relationship of fig. 7.

The method comprises the following steps: as shown in FIG. 7, the screen is placed first, and then the green LED projector is placed 3.5 meters away from the screen. The red LED projection lamp and the blue LED projection lamp are respectively arranged on the left side and the right side of the green LED projection lamp, and the distance a between the adjacent LED projection lamps is 0.385 m.

Step two: and (4) loosening a screw 203 of the universal adjuster, and adjusting the height of each LED projection lamp to 1.5 meters. And the screws 206 are loosened to adjust the LED projection lamp to be horizontal.

Step three: and turning on power switches of the LED projection lamps, and respectively rotating bases of the red LED projection lamp and the blue LED projection lamp to enable projection areas of the red LED projection lamp and the blue LED projection lamp to be overlapped with the projection areas of the green LED projection lamp.

Step four: the man substation reaches a position 2 meters away from the screen and faces the screen. A shadow on the screen is observed.

Step five: the arm is swung to observe the change of the shadow.

Step six: multiple persons participate and interact to observe the difference between the shadows of the persons and the shadows of other persons respectively.

Step seven: the man changes the distance from the screen, observes the change of the shadow, and compares with the phenomenon described in fig. 4 to 9.

The use method II comprises the following steps: and demonstrating a color shadow.

If the barrier is a senior man, typically 2d =0.44 meters, the man is a distance b =1.5 meters from the middle green LED projector, and c =2 meters from the screen, the distance a =0.77 meters between adjacent LED projectors can be found according to the geometric critical relationship of fig. 9.

The method comprises the following steps: as shown in fig. 9, the screen is placed first, and then the green LED projector is placed 3.5 meters away from the screen. The red LED projection lamp and the blue LED projection lamp are respectively arranged on the left side and the right side of the green LED projection lamp, and the distance between the adjacent LED projection lamps is 0.77 m.

Step two: and (4) loosening a screw 203 of the universal adjuster, and adjusting the height of each LED projection lamp to 1.5 meters. And the screws 206 are loosened to adjust the LED projection lamp to be horizontal.

Step three: and turning on power switches of the LED projection lamps, and respectively rotating bases of the red LED projection lamp and the blue LED projection lamp to enable projection areas of the red LED projection lamp and the blue LED projection lamp to be overlapped with the projection areas of the green LED projection lamp.

Step four: the man substation reaches a position 2 meters away from the screen and faces the screen. A shadow on the screen is observed.

Step five: the arm is swung to observe the change of the shadow.

Step six: multiple persons participate and interact to observe the difference between the shadows of the persons and the shadows of other persons respectively.

Step seven: the man changes the distance from the screen, observes the change of the shadow, and compares with the phenomenon described in fig. 4 to 9.

The invention can realize the demonstration of different kinds of color shadows by changing the position relation among the LED projection lamps or the shelters, and allows a plurality of people to participate in the demonstration to form interaction. Meanwhile, as a portable instrument, the portable instrument is greatly convenient for people to go out for science popularization. Has portability, interactivity and playability.

The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.

Claims (7)

1. A portable color shadow demonstration device is characterized by comprising a base support, a universal converter and three LED projection lamps, wherein the LED projection lamps are fixed on the base support by utilizing the universal converter, and the angles and the heights of the projection lamps are adjusted at will; the projection lamp is powered by using a mobile power supply; three projection lamps are arranged according to a certain position and then projected on a screen.

2. The portable color shadow presentation device of claim 1, wherein the portable color shadow presentation device comprises 3 base brackets, 3 universal converters, 1 red LED projector, 1 green LED projector, 1 blue LED projector, 3 lithium batteries and 1 screen, wherein the base brackets are used for supporting and suspending the LED projectors, one end of the universal converters is fixed on the base brackets, the other end of the universal converters is used for fixing the LED projectors, the lithium batteries are used for supplying power to the LED projectors, and the screen is used for displaying color shadow figures.

3. The portable color shadow presentation device according to claim 1 wherein the base mount comprises an aluminum alloy section and a weighted cast iron base, the aluminum alloy section and the weighted cast iron base being screwed together, the aluminum alloy section being vertically fixed to the weighted cast iron base.

4. The portable color shadow presentation device according to claim 3 wherein the universal converter comprises a square aluminum tube, an aluminum rod, a concave aluminum tube and a circular aluminum tube; the aluminum bar is connected with an internal thread of the square aluminum tube, the concave side of the concave aluminum tube is fixed on the aluminum bar, and the other side of the concave aluminum tube is connected with the side face of the round aluminum tube.

5. The portable color shadow presentation device of claim 1 wherein the color LED projector is a monochromatic LED lamp; the power supply mode is external power supply, and the power supply voltage is 5V.

6. The portable color shadow presentation device according to claim 1, wherein the lithium battery is a rechargeable lithium ion battery having an output voltage of 5V, the interface is a USB interface, and the power switch is provided.

7. The portable color shadow presentation device of claim 1 wherein the screen is used for color shadow projection and the screen is a vertical fiberglass plastic screen.

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