CN105022199A - Energy-saving display device and display method - Google Patents

Abstract

The invention belongs to the field of photoelectric display, and relates to an energy-saving display device and a display method. The display device includes a light-transmitting upper protective layer and a lower protective layer. There are two layers of films coated under the upper protective layer, followed by a conductive coating layer and a photosensitive layer. The lower protective layer is coated with a conductive coating layer, and the photosensitive layer is sequentially downward. There are an electrochromic layer, an ion conducting layer and an ion storage layer, and the conductive coating layers on the upper and lower protective layers are connected to lead-out electrodes for connection of driving power. After certain steps are used for electrochemical exposure and electric development, the content given by the external light source will be displayed on the display device, and the content does not need to be maintained by power supply. The invention has the characteristics of energy saving, simple manufacture and maintenance, and low cost.

Description

An energy-saving display device and display method

technical field

The invention belongs to the field of photoelectric display, and relates to an energy-saving display device and a display method.

Background technique

Display technology has developed rapidly in recent years, especially LED large-screen advertising and projection technology, which have become more and more widely used in recent years. The display effect of these technologies is very good, but the power consumption and heat generation are also very serious. The power consumption per square meter of a monochrome LED display is about 200W, and the power consumption of a color LED display is about 1000W per square meter, and it needs to consume electricity all the time during its operation. When the color display screen is working, it is very hot, and it is often necessary to install several air conditioners separately to cool it. The power consumption of the projection is about several hundred W.

When the display content changes frequently, using display devices such as LED/LCD/projection can achieve good results. However, in some cases, the content to be displayed does not change for a period of time and is relatively fixed. For example, when it is necessary to display the theme of a meeting, often during the whole meeting, the projection or screen displays the same content within several hours, which will waste a lot of energy and shorten the life of the equipment needlessly. Another example is traffic signs, in most cases, the displayed content will remain unchanged for a long time.

There is another situation that requires a display that does not change for a period of time, that is, an outdoor billboard. For example, a large number of advertisements on both sides of roads and railways. Most of these advertisements currently use inkjet printing technology, but when replacing the advertising content, the cost is relatively high, and new content needs to be inkjet again, and then the content needs to be replaced through high-altitude operations. The labor cost is high and the efficiency is low.

The present invention combines photosensitive materials, electrochromic materials and other technologies to realize an unprecedented display technology. The display device realized by using this technology only needs to be powered on when changing the display content, and then the content to be displayed can be displayed through projection or other equipment. When irradiated on this display device (named electrochemical exposure), the required content can be displayed on this display device. At this time, the power supply and the external lighting device are disconnected, and the displayed content will be stored for a long time until the operation of clearing the display is performed.

Contents of the invention

The technical problem to be solved by the present invention is to provide an energy-saving display device and a display method.

The display device of the present invention comprises a light-transmitting upper protective layer and a lower protective layer, two layers of films are coated below the upper protective layer, followed by a conductive coating layer and a photosensitive layer, and the lower protective layer is coated with a conductive coating layer, and the photosensitive There are an electrochromic layer, an ion conducting layer and an ion storage layer in sequence downwards, and the conductive coating layers on the upper and lower protective layers are connected to lead-out electrodes for connection of driving power.

The upper protective layer and the lower protective layer should use materials with high light transmission and relatively good strength. Such as glass or organic materials. If a flexible transparent material is used as a protective layer, a flexible, freely cuttable display device can be fabricated.

The content to be displayed is projected into from the upper protection layer.

Two layers of thin films are plated on the upper protective layer, which are respectively a conductive coating layer and a photosensitive layer. The order of the coating is: first conduct the coating of the conductive material, and then conduct the coating of the photosensitive material. There is only a conductive coating layer on the lower protective layer. If solid materials are used for the ion-conducting layer and the ion-storage layer, the lower protective layer can be just glass. The coating process is not required, as long as the protective layer is not damaged.

The material of the conductive coating layer can be fluorine-doped tin oxide (FTO), tin oxide or indium tin oxide, etc. The material of the photosensitive layer can be photoresistive materials such as cadmium sulfide, or photovoltaic cell materials, such as dye-sensitized materials .

The material used in the electrochromic layer is an electrochromic material, and organic electrochromic materials (such as viologens) or inorganic electrochromic materials (such as tungsten trioxide, titanium dioxide, etc.) can be selected. When enough voltage is applied across this layer, causing enough current to flow through it, the electrochromic material changes color to reveal what needs to be displayed.

The ionically conductive layer, also known as the electrolyte layer, serves the purpose of passing electrical current between the electrochromic layer and the ion storage layer. It can be liquid, sol or solid electrolyte, such as propylene carbonate, ethylene carbonate and lithium perchlorate, lithium hexafluorophosphate mixed material, lithium tantalate, etc.

The purpose of the ion storage layer is to store the counter ions generated when the electrochromic layer reacts, so as to balance the charge and ensure that the displayed content will not disappear when the external power supply is removed. Such as nickel oxide, cerium oxide, vanadium pentoxide, Prussian blue, polyaniline, phenazines, etc.

The method for displaying using the above-mentioned device of the present invention, the steps are as follows

1. Make the entire display device fully exposed, and add a positive driving voltage. At this time, the display device completely changes color and clears the previous content;

2. Disconnect the driving voltage, and at this time, the entire display device maintains a full discoloration state;

3. Use an external light source to project the content to be displayed to the upper protective layer of the display device. At this time, according to the content projected by the external light source, the unilluminated part of the photosensitive layer maintains a high resistance state, and the illuminated part becomes a conductive state;

4. Connect the reverse drive voltage, and the content to be displayed will be displayed on the display device at this time;

5. Cut off the driving voltage, turn off the external light source, and at this time, the content to be displayed will be maintained on the display device.

The device of the present invention combines electrochromic technology and photoelectric effect technology to realize an unprecedented display technology, which has the following characteristics:

1. Energy saving

It only needs to consume power when changing the display content, and does not need power supply at ordinary times, that is, the display content is self-maintaining. Even when changing the displayed content, the power consumption is very low, about 100 watts per square meter, and the process can be completed in less than a minute, which is very suitable for solar power.

2. Simple maintenance

It is only necessary to project the content to be displayed onto the device and power it on (called electrochemical exposure and electrodevelopment), and then the required content can be displayed on the device without touching the display device, and without complicated control and driving circuits . Its content will be stored for a long time without power on.

3. Simple manufacture and low cost

The key process is the large-area coating process. Compared with LCD and traditional electrochromic display technology, it does not require sophisticated photolithography technology and has a high yield. Compared with LED technology, there is no need for complicated display circuits and power supply circuits.

4. Simple structure and flexible use

The basic structure is a double-layer protective layer, and the inside is a photosensitive coating and a conductive layer coating, an electrochromic material, an ion-conducting material, and an extraction electrode. When a suitable material is used as the protective layer and a grid structure is used, the display device can be cut arbitrarily without affecting the display function.

The invention combines electrochromic technology and photoelectric effect technology. Both of these technologies are already mature and reliable technologies.

Electrochromism refers to the characteristics of certain materials (such as tungsten trioxide, viologen materials, etc.) that change in color, light transmittance, reflectance and other optical characteristics under the action of an electric field. It is already possible to use this technology for displays, but it has not seen widespread use because it has no obvious advantages.

The photoelectric effect refers to the characteristic that the resistivity of certain materials (most semiconductor materials, cadmium sulfide, etc.) changes under the condition of light and no light. According to this characteristic, a device (mainly a photoresistor) that changes in resistance according to external light can be made.

There is already a technology to place a photoresistor outside the electrochromic device, so as to realize a device that can automatically change color according to the external light intensity, but it can only change the color as a whole, and cannot display effective content.

The main idea of the invention is to incorporate a layer of photosensitive material into an electrochromic display device. Traditional electrochromic display devices cannot get rid of precision photolithography technology, so they also have the same disadvantages as LCDs, that is, there are many lead-out electrodes, many product defects, and complicated control. Once a layer of photosensitive material is added to the electrochromic display device, and then the content to be displayed is projected onto the display device, the resistance of this layer of photosensitive material will change according to the brightness and darkness of the projected content. The dark position, The resistance is still very large, and the current in this area is very small, which cannot reach the degree of conversion of the electrochromic material; at a bright position, the resistance becomes smaller, and the current in this area increases, so that the conversion of the electrochromic material occurs. Finally, the content displayed by the electrochromic display device can be determined by the pattern projected onto the display device.

Description of drawings

Fig. 1 is the schematic diagram of device structure of the present invention;

Fig. 2 is the structural diagram of the present invention when using grid structure;

Fig. 3 is a flowchart of the use of the present invention;

Fig. 4 is a schematic diagram of the use of the present invention.

Detailed ways

The technical solution of the present invention will be specifically described below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, the display device of the present invention comprises a light-transmitting upper protective layer and a lower protective layer, two layers of films are plated below the upper protective layer, followed by a conductive coating layer and a photosensitive layer, and the lower protective layer is plated with There is a conductive coating layer, and the photosensitive layer has an electrochromic layer, an ion-conducting layer and an ion storage layer in sequence, and the conductive coating layers on the upper and lower protective layers are connected to lead-out electrodes for driving power connection.

It can be seen from Figure 1 that, except for the photosensitive layer, the rest of the structure seems to be the same as that of an ordinary electrochromic display device, but in fact, it is because of this photosensitive layer that the device only needs two It is precisely because of this layer of photosensitive layer that the display method of this device is completely different from all current display devices, and it no longer uses changing electrodes for display. Drive, but "electrochemical exposure" by external light source, similar to the exposure and development of photosensitive film.

Figure 1 also expresses the situation when it is necessary to display the left half and the right half of different colors on the display device:

First, an external light source (such as a projector) is used to project the pattern to be displayed on the protective layer. In Figure 1, there is no light on the left and light on the right. At this time, the photosensitive layer on the left half has a large resistance because it is not illuminated; the photosensitive layer on the right half is exposed to light, and the resistance decreases. At this time, a driving voltage is applied between the extraction electrode 9 and the extraction electrode 10, and the current will only pass through the right half of the current channel 12 (including the electrode, the photosensitive layer, the electrochromic layer, the ion-conducting layer, and the ion storage layer), resulting in a The electrochromic material changes color, while the left part has a large loop resistance and a small current, which is not enough to cause the electrochromic material to change color. In this way, the content consistent with the projected pattern is displayed on the display device.

At this time, disconnect the external driving power connected to the electrodes 9 and 10, and turn off the external light source, then the display device will keep the pattern just generated and will not disappear.

If a flexible material (such as PET) is used for the protective layer, and the protective layers are divided into independent lattices, and the lattices are sealed with each other, a display device that can be cut and bent at will can be made. But because there is no electrochromism and no electrolyte in the isolated parts between the small grids, these isolated parts cannot display anything. Since the area occupied by the isolation part is very small, the influence on the display effect is negligible. as shown in picture 2.

Preparation Examples:

Since the manufactured display device may be used outdoors, the temperature resistance and anti-sunlight performance of the display device are more important, so the usual liquid electrolyte is not very suitable. The following uses glass as a protective material to briefly describe the manufacturing process of a display device in an all-solid state:

1. Main raw materials and equipment:

TCO glass, CdS, WO ₃ , LiTaO ₃ , NiOx, ITO, conductive metal foil, ordinary glass.

  Vacuum coating machine.

2. Main steps

First, coat each layer of material on the TCO glass in the following order: CdS, WO ₃ , LiTaO ₃ , NiOx, ITO,

Then use conductive metal foil to lead out the TCO/ITO electrodes respectively;

Place ordinary glass on one side of the ITO layer to play a protective role, and the manufacture is completed.

Example of use:

The usage steps are shown in Figure 3:

1. Make the entire display device fully exposed, and add a forward driving voltage. At this time, the display device is completely changed in color (clearing the previous content);

2. Disconnect the driving voltage;

3. Use an external light source (such as a projector) to project the content to be displayed to the display device (electrochemical exposure);

4. Access the reverse drive voltage. At this point, the content to be displayed will be displayed on the display device (electric development);

5. Disconnect the driving voltage;

6. Turn off the external light source. At this time, the content to be displayed will be maintained on the display device.

The color-changing voltage of the electrochromic device is between 1.2V and 2.0V, and the working current is about 2mA per square centimeter. Since the photosensitive layer will generate a voltage drop, the driving voltage of the entire display device needs to be increased to 5V accordingly. The color change time of the electrochromic material is less than 10 seconds, and the information can be maintained for up to 1 month after the power is cut off. Based on this calculation, a display device with an area of one square meter manufactured using this technology only needs to consume 0.83WH of electricity when the display content is changed, if all the steps of erasing the original information and updating the new information are taken into account , that is, less than 0.001 kWh. For a month thereafter, if its display remains the same, it consumes no more power.

The above embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

Claims (9)

1. an energy-conservation display device; it is characterized in that; comprise up-protective layer and the lower protective layer of printing opacity; two membranes is coated with below up-protective layer; be conduction film plating layer and photosensitive layer successively, described lower protective layer is coated with conduction film plating layer, photosensitive layer has electrochromic layer, ion conductive layer and ion storage downwards successively; conduction film plating layer on upper and lower protective seam connects extraction electrode, connects for driving power.

2. display device according to claim 1, is characterized in that, described up-protective layer, lower protective layer select glass or organic material.

3. display device according to claim 1, is characterized in that, the material of conduction film plating layer is FTO, ITO or TCO.

4. display device according to claim 1, is characterized in that, the material of photosensitive layer is cadmium sulfide, vulcanized lead, bismuth sulfide or dye sensitization material.

5. display device according to claim 1, is characterized in that, electrochromic layer Material selec-tion purpurine class or tungstic acid, titania.

6. display device according to claim 1, is characterized in that, ion conductive layer uses carbonic allyl ester, ethylene carbonate ester, lithium perchlorate or lithium hexafluoro phosphate, lithium tantalate.

7. display device according to claim 1, is characterized in that, ion storage selects nickel oxide, cerium oxide, vanadium pentoxide, Prussian blue, polyaniline or azophenlyene class.

8. display device according to claim 1, is characterized in that: display device adopts cell structure.

9. use device described in claim 1 to carry out the method shown, it is characterized in that step is as follows:

1), whole display device is exposed completely, and adds positive drive voltage, the now complete variable color of display device, the content before removing;

2), disconnect driving voltage, now whole display device maintains whole color change state;

3), will need the up-protective layer of contribute content display device of display with external light source, now the content that project according to external light source of photoresistor layer, the part be not illuminated maintenance high resistance state, the part be illuminated becomes conduction state;

4), access reverse drive voltages, now display device will demonstrate the content needing display;

5), disconnect driving voltage, close external light source, now display device will maintain the content needing display.