JP2000089696A - Display information erasure device and display information rewrite device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent printing thinning from occurring due to a charge remaining at an erasure time. SOLUTION: This device is a display information erasure device used for a reversible display card 100 provided with a display part 100a rewriting display information and erasing the display information displayed on the display part, and contains an erasing electrifier 31 electrifying the charge on the display part of the reversible display card 100 without contacting and an earth roller 32a arranged adjacent to the erasing electrifier 31, being in contact with the reversible display card 100 and removing a surface charge, and is provided with an erasure part 31 applying an electric field to the display part and erasing the display information and a destaticizing electrifier 33 applying a polarity opposite to the charge of the erasing time of the erasing electrifier 31 or AC, and neutralizes the charge remaining on the reversible display card 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display information erasing device for erasing display information on a reversible display medium and a display information rewriting device for rewriting the display information.

[0002]

2. Description of the Related Art A reversible display medium has a reversible display unit using a reversible display element in which display information can be rewritten. This reversible display element is, for example, a liquid crystal / polymer composite film (Polymer Dispersed Liq) in which a liquid crystal such as a smectic liquid crystal is dispersed in a polymer matrix.
uid Crystal film, hereinafter referred to as PDLC film)
And the like (JP-A-5-294092).

A reversible display device using this PDLC film utilizes light scattering and light transmission due to a change in the order of liquid crystal molecular alignment due to heat and an electric field. , Transparency (light transmission) is used as the erased state. Therefore, writing is performed using a thermal head, and erasing is performed by sandwiching the PDLC film between electrodes and applying a voltage equal to or higher than the threshold value of liquid crystal alignment to align the liquid crystal.

Japanese Patent Application Laid-Open No. 8-202294 discloses a charger which is charged positively or negatively and is not in contact with the surface of a PDLC film.
An electrode is provided on the same side as the charger and is brought into contact with the surface of the PDLC film, and a method for aligning the liquid crystal using a potential difference between the charge by the charger and the electrode is disclosed.

Japanese Patent Laid-Open No. Hei 8-171977 discloses a rewriting device that erases by applying an electric field and prints by heating. The erasing means of this apparatus is excellent in that the method of applying an electric field by corona discharge applies an electric field uniformly including minute irregularities on the surface. Further, the erasing means does not come into contact with the reversible display medium, and therefore may be durable.

[0006]

FIG. 4 is a diagram for explaining the problems of the conventional display information erasing device. In FIG. 4, reference numeral 100 denotes a reversible display card (reversible display medium), 61
Is a corona electrode of the charger, and 62a and 62b are earth rollers serving as a static eliminator. Conventional display information erasing devices are:
The corona electrode 61 and the earth rollers 62a and 62b are provided on the front side of the reversible display card 100, and the reversible display card 100 is transported in the direction of arrow A. At the time of (a), the discharge is turned on, and ( At the point b), the discharge is turned off. For this reason, after corona discharge, charge is removed in the range of arrow B, and charge remains in the range of arrow C indicated by hatching, and the effect of charge removal is limited. Note that by shortening the distance between the corona electrode 61 and the earth rollers 62a and 62b, the charge removal range can be reduced, but there is a physical limit.

As described above, when the reversible display card 100 is charged, the liquid crystal is vertically aligned by the electric field even after printing by heating, which causes print blur.
In order to suppress the print blur, it is conceivable to increase the printing energy. However, there is a possibility that the PDLC film of the reversible display card 100 is damaged and an afterimage of erasure appears.

On the other hand, as a static elimination means, a static elimination brush, an ion blow, an ion bar, and the like are known, and many of them are commercialized. There is. For example, a static elimination brush is less effective at low levels of charging. In the case of ion blow, ion bar, etc., the size of the device is large,
Immediate static elimination is not possible.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a display information erasing device and a display information rewriting device capable of preventing the occurrence of print blur due to the charge remaining during erasing.

[0010]

According to an aspect of the present invention, there is provided a reversible display medium having a rewritable display section in which display information is rewritable, wherein the display information is displayed on the reversible display section. A display information erasing device for erasing the displayed information, wherein the erasing charger and the erasing charger are arranged adjacent to the erasing charger for charging the non-contact reversible display medium without contact. A display information erasing unit for erasing the display information by applying an electric field to the reversible display unit, the display information erasing unit including a static eliminator for removing a surface charge in contact therewith; and a charge for neutralizing a charge remaining on the reversible display medium. And a neutralizing means.

According to a second aspect of the present invention, in the display information erasing apparatus according to the first aspect, the charge neutralizing means applies a reverse polarity or alternating current to the charge at the time of erasing of the erasing charger. And a display information erasing device.

According to a third aspect of the present invention, in the display information erasing apparatus according to the first aspect, the apparatus further comprises a transport unit for transporting the reversible display medium, and the charge neutralizing unit is configured to perform the reversible display by the transport unit. A display information erasing apparatus, wherein a medium is returned to the position of the erasing charger, and a polarity or an AC opposite to the charge at the time of erasing is applied using the erasing charger.

According to a fourth aspect of the present invention, there is provided the first to third aspects.
The display information erasing apparatus according to any one of the preceding claims, further comprising an auxiliary erasing section for previously performing an entire writing by heating on the variable display section of the reversible display medium. is there.

According to a fifth aspect of the present invention, there is provided the first to fourth aspects.
A display information rewriting device, comprising: the display information erasing device according to any one of the above items; and a writing device that writes display information to the reversible display unit of the reversible display medium by heating. .

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described in more detail.
FIG. 3 is a diagram showing a reversible display card to be rewritten by the display information rewriting device of the present embodiment. Reversible display card 10
0 denotes a card base 101 made of an insulating material such as a plastic sheet, as shown in FIG.
A transparent electrode such as an O film, a conductive layer 102 made of a metal vapor-deposited film of aluminum or the like, a metal foil, and a material in which a smectic liquid crystal is dispersed in a polymer matrix. PD that can rewrite visible information by causing the liquid crystal to be in a regular alignment state such as homeotropic alignment or homogeneous alignment.
In order to protect the LC film 103 and the PDLC film 103,
A protection layer 104 formed by laminating a resin film or applying a resin liquid;

FIG. 1 is a diagram showing an embodiment of a display information rewriting device according to the present invention, and FIG. 2 is a schematic diagram for explaining the operation of the display information rewriting device according to this embodiment. The display information rewriting device 10 includes a writing unit 20, an erasing unit 30, an auxiliary erasing unit 40, a transport unit 50, and the like.

The writing section 20 writes display information on the display section 100a of the reversible display card 100 (PDLC film 103).
The thermal head 21 is capable of displaying an arbitrary character or figure by heating a predetermined portion in a spot manner.

The erasing section 30 is a section for orienting the liquid crystal of the PDLC film 103 regularly so as to be in an erasing state. The erasing section 30 is provided with a corona electrode 31a for charging a charge without contacting the reversible display card 100. A charger 31 and a static eliminator 32 that is grounded and removes surface charges from the surface of the reversible display card 100 by rotating and contacting the ground rollers 32a and 32b with the charged surface of the reversible display card 100 are provided.

In this embodiment, a charger 33 for removing electricity is further provided. The static eliminator 33 is used as charge neutralizing means for neutralizing the charge remaining on the reversible display card 100.

The auxiliary erasing section 40 is a section for heating the display section 100a to a uniform opaque state (whole written state) by heating before erasing by the erasing section 30, and eliminating erasing unevenness. , A heating plate 41 and the like.

The transport unit 50 is provided within the apparatus for reversible display card 1
00 is a part for transporting the transport belt 51,
It is composed of transport rollers 52, 53 and the like. In addition,
Writing unit 20, erasing unit 30, auxiliary erasing unit 40, transport unit 50
And the like are controlled by a control unit (not shown) as in the operation described later.

Next, the operation of the display information rewriting device of this embodiment will be described. First, the reversible display card 100 is transported to a lower portion of the heating plate 41 by the transport unit 50. In the reversible display card 100, the PDLC film 103 is heated by the heating plate 41, and the entire surface is written. Thereafter, in the process of being conveyed back to the card entrance 51 side, it is erased by the erasing unit 30 and printed by the writing unit 20.

As shown in FIG. 2A, the erasing section 30 includes a surface portion of the display section 100a positively (or negatively) charged by the charger 31, a PDLC film 103, and a conductive layer 102.
-PDLC film 103-Earth roller 32a of static eliminator 32
A potential difference is generated along the path, and charges are applied vertically to the liquid crystal in the PDLC film 103 to erase the display.

Here, the reversible display card 100 after erasing is used.
As shown in FIG. 2B, as shown in FIG. 2B, a small amount of charge remains even in the charge elimination range B, and almost no charge is removed in the non-charge elimination range C.

Next, the charging device 33 for discharging performs discharge of the opposite polarity. The discharge of the opposite polarity is weakened and electrically neutralized. For example, as shown in FIG. 2A, a positive charge is applied by a corona electrode of the erasing charger 31,
Due to the potential difference from the earth roller 32, the PDLC film 103
When an electric field is applied to the surface of the reversible display card 100, as shown in FIG. Neutralize with charge. The polarity of the erasing charger 31 and the charge elimination charger 33 may be reversed, or alternating current may be applied to the corona electrode of the charge elimination charger 33.

As described above, in this embodiment, P
In the erasing device for the reversible display card 100 using the DLC film 103, the erasing unit 30 performs the application of an electric field by corona discharge of the erasing charger 31, and the printing unit performs heating by a thermal head. However, as a result of the application of the electric field, the reversible display card 100 is charged, and even after printing by heating, vertical orientation is caused by the electric field, which causes print blur. Therefore, in the present embodiment, the erasing charger 3 is used.
Since the charge removing charger 33 for performing the reverse polarity or alternating current corona discharge of No. 1 was provided, the above-described charge was neutralized, and print blurring was prevented.

(Modifications) Various modifications and changes are possible without being limited to the embodiment described above, and they are also within the equivalent scope of the present invention. For example, although the description has been given of the example of the rewriting device, the rewriting device may be used as an erasing device.

Further, in the present embodiment, a corona electrode of the charging device 33 for static elimination is added downstream of the transport direction, and is electrically neutralized by applying a reverse polarity or an alternating current to that applied at the time of erasing. As described in the example, after the eraser is erased by the charger 31 and the earth rollers 32a and 32b, the reversible display card 100 is sent backward by the transport unit 50 to the upstream in the transport direction A, and is applied to the corona electrode of the eraser charger 31. The charge may be neutralized by applying a reverse polarity or alternating current to neutralize the charge.
As a result, an increase in the size of the apparatus can be prevented, and the processing time can be reduced.

[0029]

As described above, the present invention has the following effects. (1) Since the charge neutralizing means is provided, the charge on the reversible display medium can be completely removed, and the occurrence of printing unevenness can be prevented. (2) In addition, unlike the related art, it is not necessary to increase the printing energy in order not to cause printing unevenness, and as a result, it is possible to prevent an afterimage of erasure. (3) Since the charge can be removed at the transport speed of the reversible display medium, the processing speed is not reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a display information rewriting device according to the present invention.

FIG. 2 is a schematic diagram illustrating an operation of the display information rewriting device according to the embodiment.

FIG. 3 is a diagram showing a reversible display card to be rewritten by the display information rewriting device of the embodiment.

FIG. 4 is a diagram illustrating a problem of a conventional display information erasing device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 display information rewriting device 20 writing unit 21 thermal head 30 erasing unit 31 erasing charger 32 static eliminator 32a, 32b ground roller 33 static eliminator 40 auxiliary erasing unit 41 heating plate 50 transport unit 100 reversible display card 100a Display unit 101 Card base 102 Conductive layer 103 PDLC film 104 Protective layer

Claims (5)

[Claims] 1. A display information erasing device for use in a reversible display medium having a reversible display unit in which display information is rewritable and for erasing display information displayed on the reversible display unit.
An erasing charger that charges electric charges in a non-contact manner on the reversible display portion of the reversible display medium and an erasing device that is disposed adjacent to the erasing charger and contacts the reversible display medium to remove surface charges. A display information erasing unit for erasing the display information by applying an electric field to the reversible display unit; and a charge neutralizing unit for neutralizing charges remaining on the reversible display medium. Display information erasing device. 2. The display information erasing device according to claim 1, wherein the charge neutralizing means is a charge erasing device for applying a polarity or an AC opposite to a charge at the time of erasing of the erasing device. A display information erasing device characterized by the above-mentioned. 3. The display information erasing device according to claim 1, further comprising a transport unit that transports the reversible display medium, wherein the charge neutralizing unit uses the transport unit to erase the reversible display medium for erasing. A display information erasing device, wherein the display device is returned to a position of a charger, and the opposite polarity or alternating current to the charge at the time of erasing is applied using the erasing charger. 4. One of claims 1 to 3
3. The display information erasing device according to claim 1, further comprising an auxiliary erasing unit for previously performing an entire writing by heating on the variable display unit of the reversible display medium. 5. The method according to claim 1, wherein:
A display information rewriting device, comprising: a display information erasing device according to any one of the preceding items, and a writing device that writes display information to the reversible display section of the reversible display medium by heating.