JPH06186520A - Electronic blackboard device - Google Patents

Abstract

PURPOSE:To obtain an electronic blackboard device in which erasing time is shortened and the scattering of ink and the dirt of a blackboard are prevented. CONSTITUTION:A display medium consisting of high polymer dispersed liquid crystal is formed between two sheet materials 5a and 5b which are disposed to face oppositely. When write is performed on the surface of the blackboard by a touch pen 7, electric field is given to the display medium at a write part through an ITO electrode 3, and the oriented state of the liquid crystal at that part is changed. By removing one part or all of the electric field, the oriented state is restored to an original state and erasion is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic blackboard device used as an OA information processing device.

[0002]

2. Description of the Related Art Hitherto, as an electronic blackboard device, a white paper sheet of a winding type has been used for writing with a marker pen or the like. In such a device,
Usually, it has a polymer sheet for 5 screens, and the screen is changed by mechanically feeding it. Further, a character input device is provided at the end of the device and has a screen reading / copying function. Then, erasing is performed by erasing the blackboard as in the conventional blackboard.

[0003]

In the electronic blackboard device described above, digitization has been promoted by having a copying function, but writing and erasing are performed in the same manner as in the conventional blackboard. Therefore, basic problems such as time-consuming erasure, blackboard stains, and ink splatter from the pen remain unsolved.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an electronic blackboard device capable of shortening erasing time and preventing ink scattering and blackboard stains. To do.

[0005]

The electronic blackboard device of the present invention is sandwiched between two sheet materials which are disposed opposite to each other, at least one of which is transparent, and a part or all of which is a liquid crystal. And a writing / erasing means for erasing by changing the orientation state of the liquid crystal in the display portion of the display medium for writing and restoring the orientation state. A certain sheet material is arranged on the front side and used, whereby the above-mentioned object is achieved.

The display medium is composed of polymer dispersed liquid crystal,
The writing / erasing means applies an electric field to a portion of the display portion where writing is performed to change the alignment state of liquid crystal in the portion to perform writing, and in the case of full erasing, it is applied to the display portion. The configuration may be such that the electric field is collectively removed to restore the alignment state.

The writing / erasing means may have a partial removal function of partially removing the electric field of the display section in which the writing is performed to restore the alignment state of the liquid crystal.

A dichroic dye may be dispersed in the liquid crystal.

The display medium is made of polymer liquid crystal, and the writing / erasing means applies heat to a portion of the display portion where writing is performed to change the alignment state of the liquid crystal in the portion and performs writing. In the case of erasing, heat may be applied to the entire area of the display portion again to restore the orientation state.

The writing / erasing means may have a function of removing a portion of the display portion where writing is performed by reheating the portion to which heat is applied to restore the alignment state.

A dye may be dispersed in the polymer liquid crystal.

[0012]

The electronic blackboard device of the present invention is provided with the writing / erasing means for performing the writing by partially changing the alignment state of the liquid crystal of the display part and for erasing by returning the alignment state to the original state. . When writing, the alignment state of the liquid crystal in the written portion is changed to change the optical characteristics such as the refractive index and the scattering rate of light. As a result, writing is performed and the written characters / figures are visually recognized. Further, when the alignment state of the liquid crystal in the written portion is returned to the state before the writing, the optical characteristics return to the original state and the erasing is performed.

When polymer dispersed liquid crystal is used as the display medium, writing can be performed by applying an electric field. When an electric field is applied to the writing portion of the display portion, the liquid crystal in that portion is aligned in the electric field direction. At this time, if the dichroic dye is dissolved in the liquid crystal, the dye molecules are also arranged in the same direction as the liquid crystal and decolored or colored, so that writing can be made clear. When erasing the entire surface, erasing can be performed quickly by removing all of the electric field applied to the display section. Further, partial removal can be performed by partially removing the electric field of the display portion where writing is performed. If an electromagnetic induction type or capacitance type position detection panel or the like is provided, the position of the written portion or the erased portion can be detected using this. Then, an electric field is applied to the detected portion of the display portion to perform writing, or the applied electric field is removed, whereby partial erasing can be performed.

When a polymer liquid crystal is used as the display medium, writing can be performed by heat. When the liquid crystal in the display section is partially heated, the liquid crystal becomes an anisotropic state. When this liquid crystal is rapidly cooled, the liquid crystal becomes in a random alignment state, the incident light is scattered, white display is performed, and it is visually recognized as writing. As such heating means, for example, laser light whose irradiated portion is linear can be used. At this time, if a dye or the like is contained in the display medium, light is scattered at a portion to which heat is applied, resulting in white display,
Since the color of the pigment is displayed in the part where heat is not applied,
Writing can be made clear. In the case of erasing, heat is applied to the liquid crystal of the display unit in which the writing has been performed to gradually cool it. As a result, the liquid crystal is rearranged to return to the original alignment state and erasing can be performed. Further, by providing a heater or the like around the display surface, heat can be applied to the entire surface of the display medium, so that erasing can be performed quickly.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1A is a sectional view showing an electronic blackboard device which is an embodiment of the present invention. This electronic blackboard device has polymer sheets 5a and 5b arranged opposite to each other.
In the meantime, the polymer-dispersed liquid crystal in which the liquid crystal 2 is dispersed in the polymer 1 serves as a display medium. A dichroic dye 6 is dispersed in the liquid crystal 2 so that color can be developed. Polymer sheet 5
ITO (Indium Tin Oxid) is provided on the display medium side of a and 5b.
e) The electrode 3 is formed to change the alignment state of the liquid crystal 2. An electromagnetic induction panel 4 provided with electromagnetic induction wiring is provided on the side of the polymer sheet 5b opposite to the display medium so as to detect the position of writing or erasing applied by the touch pen 7 or the like from the side of the polymer sheet 5a. It has become.

Here, as the liquid crystal 2, any liquid crystal whose orientation state changes by application of an electric field can be used, and for example, PCH liquid crystal can be used. Also, by selecting the dichroic dye 6, blackboard surfaces of various colors can be obtained.

The electronic blackboard device can be manufactured as follows.

First, a polymer sheet 5a, 5b made of polyester or the like is sputtered with a thickness of 200
A 0 angstrom ITO film is laminated. This is patterned into a stripe shape by photolithography to form the ITO electrode 3.

Next, the polymer sheets 5a and 5 in this state
On one side of b, a polymer-dispersed liquid crystal in which the dichroic dye 6 is dispersed in the liquid crystal 2 is applied to a thickness of 10 μm and dried to form a display medium. The other polymer sheet is laminated on this. Further, a tablet is connected to the periphery of the ITO electrode 3 to draw it out, and this is connected to a drive circuit. Then, the electromagnetic induction panel 4 incorporating the electromagnetic induction wiring is provided on the back surface of the polymer sheet 5b.

Then, as shown in FIG. 3, the display portion 12 in this state is incorporated into the electronic blackboard board to operate the operation panel 11.
Attach the to complete the electronic blackboard.

In this electronic blackboard device, the touch pen 7
When writing is performed by, for example, the writing unit is detected by the electromagnetic induction panel 4. Then, a voltage is applied to the display medium of the writing section by the ITO electrode 3, and the liquid crystal 2 is oriented in the electric field direction. Along with this, the dichroic dyes 6 are also arranged in the electric field direction, and writing is performed on the display section of the display medium.

FIG. 1 (b) shows the results of measuring the optical characteristics of the writing section and the display section of the portion where no writing was performed in the electronic blackboard device. Here, an anthraquinone dye is used as the dichroic dye 6. As can be seen from this figure, a portion of the display medium where no electric field is applied shows blue (λ = 450 nm) and a writing portion where an electric field is applied shows white. As a result, the writing is visually recognized as a white display on the blue blackboard surface.

In this electronic blackboard device, the entire erase is
By removing the electric field over the entire display portion of the display medium, the operation can be performed quickly. Further, in the partial erasing, the erasing by the touch pen 7 having a certain area or the like is detected by the electromagnetic induction panel 4. Then, it can be performed by removing the electric field applied to the display medium of the erasing section.

The page can be changed by providing a memory function and storing the entire screen. Also, page reading can be performed by reading the memory.

In the above embodiment, the position of the writing / erasing unit was detected using the touch pen and the electromagnetic induction panel, but a capacitance type touch panel may be used.
In addition, it is also possible to use an ultrasonic optical method used in a free cursor type digitizer or the like, or a current division method using resistance. Further, the positions of the writing unit and the erasing unit can be designated by an optical, magnetic, mechanical, or other pointing device or a light pen.

(Embodiment 2) FIG. 2A is a sectional view showing an electronic blackboard device which is another embodiment of the present invention. This electronic blackboard device includes a polymer sheet 15a disposed opposite to each other,
The polymer liquid crystal 18 is provided between 15b as a display medium. A blue or black dye 16 is dispersed in the polymer liquid crystal 18. The pen 19 incorporating the laser beam 10 and the like applies heat.

Here, as the polymer liquid crystal 18, any one can be used as long as the alignment state is changed by heat applied from the outside, and for example, a polyester liquid crystal polymer or the like can be used. Also, dye 1
By selecting 6, it is possible to obtain blackboard surfaces of various colors.

The electronic blackboard device can be manufactured as follows.

First, a polymer-dispersed liquid crystal in which a dye 16 is dispersed in a polymer liquid crystal 18 is applied to one of the polymer sheets 15a and 15b made of polyester to have a thickness of 20 μm and dried to form a display medium. The other polymer sheet is laminated on this.

Then, as shown in FIG. 3, the display portion 22 in this state is incorporated in the electronic blackboard board and the operation panel 11 is installed.
Attach the to complete the electronic blackboard.

In this electronic blackboard device, when a laser beam is applied to the liquid crystal of the writing section by the pen 19, the liquid crystal 1
8 is heated to be in an isotropic orientation state. In this case, since the writing portion is linear, the writing portion is rapidly cooled and the liquid crystal is in a random alignment state. As a result, writing on the display unit is performed.

FIG. 2B shows the results of measuring the optical characteristics of the display medium in the writing section and the non-writing section in the electronic blackboard device. Here, a blue dye was used as the dye 16. As can be understood from this figure, blue (λ
= About 450 nm), and the incident light is scattered at a portion where writing is performed by applying heat to the display medium, and a white color is obtained.
As a result, the writing is visually recognized as a white display on the blue blackboard surface.

In this electronic blackboard device, the entire erase is
After winding the polymer sheet, heat can be applied to the entire display portion of the display medium by a line-shaped heater or the like provided at the end of the device, and then gradually cooled.
When the liquid crystal is gradually cooled after being heated, the liquid crystal rearranges and returns to the original alignment state, so that the display surface becomes the background color which is the color of the dye 16. Further, partial erasing can be performed by applying heat with a light pen or the like having a laser light flux of a certain area and gradually cooling.

Similar to the first embodiment, the page can be changed by providing a memory function and storing the entire screen. Also, page reading can be performed by reading the memory.

Any method can be used for writing / erasing as long as it is a method of changing the alignment state of the liquid crystal.
For example, a magnetic field or the like can be used.

[0037]

As is apparent from the above description, according to the present invention, since it is possible to obtain an electronic blackboard device capable of writing and erasing by changing the alignment state of liquid crystal, it is possible to shorten the erasing time and It is possible to prevent scattering and dirt on the blackboard.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an electronic blackboard device of the present invention. (A) is a cross-sectional view and (b) shows the results of measuring the optical characteristics of the display medium.

FIG. 2 is a diagram showing another embodiment of the electronic blackboard device of the present invention. (A) is a cross-sectional view and (b) shows the results of measuring the optical characteristics of the display medium.

FIG. 3 is a diagram showing an example of a schematic configuration of an electronic blackboard device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polymer 2 Liquid crystal 3 ITO electrode 4 Electromagnetic induction panel 5a, 5b, 15a, 15b Polymer sheet 7 Touch pen 19 Pen which heats by laser etc.

Claims (7)

[Claims] 1. A pair of sheet materials, which are opposed to each other, at least one of which is transparent, a display medium which is sandwiched between the two sheet materials and which is partially or wholly made of liquid crystal, and a display portion of the display medium. The writing and erasing means for writing by partially changing the alignment state of the liquid crystal in, and erasing by restoring the alignment state are used, and a transparent sheet material is arranged on the front side. Electronic blackboard device 2. The display medium is composed of polymer dispersed liquid crystal, and the writing / erasing means applies an electric field to a writing portion of the display section to change the alignment state of the liquid crystal in the writing portion. The electronic blackboard device according to claim 1, wherein the electric field applied to the display portion is collectively removed to restore the alignment state in the case of erasing the entire surface. 3. The writing / erasing means has a partial removal function of partially removing an electric field of a display section in which writing is performed to restore an alignment state of liquid crystal. The electronic blackboard device described in. 4. The electronic blackboard device according to claim 2, wherein a dichroic dye is dispersed in the liquid crystal. 5. The display medium is composed of a polymer liquid crystal, and the writing / erasing unit applies heat to a portion of the display unit where writing is performed to change the alignment state of the liquid crystal in the portion to perform writing. 2. The electronic blackboard device according to claim 1, wherein in the case of erasing the entire surface, heat is applied again to the entire area of the display unit to restore the alignment state. 6. The structure according to claim 5, wherein the writing / erasing means has a part removing function for returning the alignment state to the original state by applying heat again to the heat application part of the display part in which writing is performed. The described electronic blackboard device. 7. The electronic blackboard device according to claim 5, wherein a dye is dispersed in the polymer liquid crystal.