JPH1055139A - Electronic information display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an erasing characteristics of an image formed on a magnetic display body by forming an intensity distribution of a magnetic field of an opposite surface confronted with a magnetic display body of an erasing means so as to become weeker in a down stream end part of a transportation of a magnetic display body than that of a middle part of a confronted surface. SOLUTION: In an erasing head 20, an erasing magnet 20a composed of a planer permanent magnetic having a length larger than a width of a magnetic display sheet 10 is fixed to a planer part of a supporting member 21 formed with a metal of high permeability such as iron material having a U-shaped cross section. A film 20c having a smooth front surface is stick to a surface of the erasing magnet 20a. The erasing magnet 20a is magnetized so that an N pole and an S pole are periodically arranged with a prescribed pitch. A magnetizing pitch is formed so as to gradually decrease from a middle part to an end part side. By such an arrangement, an intensity distribution of a magnetic field on a contact surface of the sheet is formed so as to become weeker on the end part than in the middle part and, specially when a magnetic display sheet 10 is separated from a contact surface, the erasing magnetic field is made to gradually attenuate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electronic information display device for recording and displaying a still image on a magnetic display based on print information sent from an external host device.

[0002]

2. Description of the Related Art Conventionally, a magnetically responsive magnetic display sheet has been known as a display body which develops or erases color in response to the direction and strength of a magnetic field (for example, Japanese Patent Application Laid-Open No. 48-48).
56393, JP-A-2-146082).

[0003] Such a magnetic display sheet can draw simple characters and figures by contacting a magnet pen with a built-in magnet on the sheet surface, and can be reused many times by erasing. Has been put to practical use.

In recent years, an electronic information display device has been developed which records and displays a still image on a magnetic display sheet by a recording head forming a dot matrix magnetic field based on print information sent from an external host device. Is being done.
Since the electronic information display device can change the display content arbitrarily by remote control from an external host device, it can be installed at public facilities, stations, retail stores, etc. Can be widely announced and advertised. In addition, poster replacement work is not required, which contributes to resource saving of paper and the like, and is therefore expected to be a future bulletin board.

[0005]

In such an electronic information display apparatus, a magnetic display sheet is formed endlessly and circulated and conveyed to perform sub-scanning, and the recording head is reciprocated in the sheet width direction to perform main scanning. To perform two-dimensional scanning.

When erasing an image, an erasing head having a length equal to or more than the sheet width is brought into close contact with the back side of the magnetic display sheet, and continuous erasing can be performed by moving the magnetic display sheet.

It is simple to use a single permanent magnet as the erasing head. In this case, however, the erasing magnetic field distribution on the magnetic display sheet has a square wave shape that changes stepwise along the sheet conveying direction. That is, when a certain portion of the magnetic display sheet moves and comes into contact with the erasing head, the erasing magnetic field rises sharply, and thereafter an erasing magnetic field of almost constant intensity is applied. .

[0008] Therefore, in the case where the magnetic display sheet is fed unevenly or intermittently conveyed using a pulse motor or the like, the time variation of the applied magnetic field becomes large, and a striped pattern corresponding to the speed fluctuation cycle is formed. In some cases, it remains and cannot be completely erased.

It is an object of the present invention to provide an electronic information display device which can improve the erasing characteristics of an image formed on a magnetic display.

[0010]

SUMMARY OF THE INVENTION The present invention provides a magnetic display which can be magnetically written and erased, a transport means for transporting the magnetic display, and a print signal from the outside.
A recording unit for applying a recording magnetic field on the magnetic display to form a still image, and a facing surface facing the magnetic display,
Erasing means for erasing a recorded image by generating an erasing magnetic field from the erasing surface, wherein the magnetic field intensity distribution on the opposite surface is weaker at the transport downstream end of the magnetic display body than at the center of the opposite surface. An electronic information display device characterized by being formed as described above. According to the present invention, by forming the magnetic field intensity distribution on the opposing surface of the erasing means such that the transport downstream end of the magnetic display is weaker than the central portion, when the magnetic display separates from the opposing surface. Then, the erasing magnetic field gradually decreases. Therefore, the time change of the erasing magnetic field applied to the magnetic display body is reduced, so that the influence of uneven feeding or intermittent feeding can be reduced, and a striped pattern corresponding to a speed fluctuation cycle can be particularly eliminated.

Further, the present invention is characterized in that the erasing means is constituted by a planar permanent magnet whose polarity is alternately reversed in the conveying direction of the magnetic display. According to the present invention, since the polarity of the permanent magnet is alternately reversed, when the magnetic display body moves while contacting the erasing means, the magnitude and direction of the erasing magnetic field periodically change. . For this reason, the magnetic particles constituting the magnetic display body largely move, and finally settle at a position where the erasing characteristics are good. Thus, erasure with less erasure and high contrast can be realized.

[0012]

FIG. 1 is a side sectional view of an electronic information display device according to the present invention, and FIG. 2 is a partial perspective view thereof. A driven roller 50 is disposed on the inner upper portion of the housing 1, and a driving roller 60 is disposed on the inner lower portion. A flexible and endless magnetic member is provided between the two rollers 50 and 60. The display sheet 10 is suspended. Roller 5
Numeral 0 is urged upward by an elastic member (not shown) such as a spring, and applies a constant tension to the magnetic display sheet 10 to stabilize the running of the sheet and maintain the flatness of the sheet surface. The roller 60 is driven to rotate by a motor 63 such as a pulse motor via gears 61 and 62.
The driving of the roller 60 causes the magnetic display sheet 10
Are from bottom to top on the front side of the housing 1 (right side of FIG. 1, rear side of FIG. 2), and from top to bottom on the rear side of the housing 1 (left side of FIG. 1, front side of FIG. 2). Circulate to transfer to

A display window 2 made of a transparent material such as acrylic resin or glass is formed on the front surface of the housing 1, and an opaque portion 2a is formed on the upper and lower portions of the display window 2 to hide the internal mechanism. .

The magnetic display sheet 10 is stretched between rollers 50 and 60 to form two opposing surfaces, and the front sheet is close to the display window 2. The rear side sheet is pressed by a pair of rollers 51 and 52 that change the sheet conveyance path, and is displaced toward the front side sheet to the vicinity of an imaginary plane connecting the respective central axes of the rollers 51 and 52. By providing the rollers 51 and 52 for changing the path, the space surrounded by the magnetic display sheet 10 can be reduced, and a space is created in the internal space on the back side of the device, which contributes to the reduction in thickness of the device. .

The recording head 30 is a sheet on the back side of the magnetic display sheet 10 and is installed below a flat portion on a transport path between the rollers 51 and 52, and prints from an external host device (not shown). A dot-matrix recording magnetic field is generated toward the surface of the magnetic display sheet 10 based on the signal. The recording head 30 has a plurality of electromagnetic coils arranged in a staggered manner, for example, and is mounted on a carriage 31 that reciprocates in the sheet width direction. The carriage 31 is 2
Endless belt 3 suspended between two pulleys 34, 35
3 and a motor 36 that drives the pulley 35 to rotate while being guided by the two guide shafts 32.
Driven by

In order to maintain the flatness of the printing portion of the recording head 30, a plate-like platen 25 having a length about the sheet width is provided so as to sandwich the magnetic display sheet 10, and the platen 25 has a U-shaped cross section. The support member 26 is fixed to the support member 26.
On the surface of the platen 25, a film 2 having a smooth surface
5a is adhered, and the running of the sheet is stabilized while maintaining the close contact with the magnetic display sheet 10. The film 25a is formed of a synthetic resin film such as PET (polyethylene terephthalate), and is further provided with conductivity and grounded to the housing 1 to prevent triboelectric charging.

If the rollers 51 and 52 for changing the path are not provided, the recording head 30 protrudes from the rear sheet to the rear side, and the depth of the apparatus is required by the thickness of the recording head 30. As a countermeasure, by providing rollers 51 and 52 for changing the path, the magnetic display sheet 1
Since 0 is displaced to the front side, the projection of the recording head 30 is reduced, and the device is made thinner.

A sensor P for detecting the reference position of the magnetic display sheet 10 is provided near the upstream side of the recording head 30 in the sheet conveyance.
Is provided. The sensor P is composed of, for example, a photo sensor including a light emitting diode and a photodiode,
The initial position of the magnetic display sheet 10 is detected by detecting the presence or absence of a transmission hole (not shown) formed at the end of the magnetic display sheet 10.

The erasing head 20 has a supporting member 21 in which an erasing magnet 20a made of a planar permanent magnet having a length equal to or greater than the sheet width is formed of a metal having high permeability, such as iron having a U-shaped section.
Above the front surface of the magnetic display sheet 10, and is disposed so as to face and closely contact the rear surface of the magnetic display sheet 10.

A film 20c having a smooth surface is stuck to the surface of the erasing magnet 20a to stabilize the running of the sheet while maintaining the adhesion to the magnetic display sheet 10. The film 20c is formed of a synthetic resin film such as PET, and by using such a nonmagnetic material, the erasing magnetic field from the erasing magnet 20a can reach the magnetic display sheet 10 without being attenuated. Further, by imparting conductivity to the film 20c and grounding the housing 1, triboelectric charging is prevented.

Further, the magnetic display sheet 10 is
A pair of pressing rollers 53 and 54 are provided for pressing to the 0 side. The pressing roller 53 is disposed near the center of the erasing magnet 20a, and the pressing roller 54 is disposed near the downstream end of the erasing magnet 20a. The shafts of the pressing rollers 53 and 54 are supported so as not to be displaced with respect to the erasing head 20, and the roller peripheral surface is formed of an elastic material such as rubber or synthetic resin.
0 and the erasing head 20 are improved in adhesion. Therefore, even if the magnetic display sheet 10 vibrates during traveling, the erasing magnetic field applied to the magnetic display sheet 10 can be maintained at a sufficient level, and the erasing characteristics are improved.

The axes of the pressing rollers 53 and 54 may be supported by an elastic member such as a spring so as to be displaceable with respect to the erasing head 20, and although the configuration is slightly complicated, a wide elastic pressing area is secured. it can.

Further, the entire write head 22 made of a permanent magnet or the like having a length equal to or longer than the sheet width is used as the erase head 2.
The magnetic display sheet 10 is provided so as to be in close contact with the front surface side of the magnetic display sheet 10 at the upstream side of the conveyance direction 0, and by forcibly performing full writing before erasing, the fluidity of the magnetic particles in the sheet is increased to improve the erasing characteristics. ing.

FIG. 3 is a partial sectional view showing the structure of the magnetic display sheet 10 and the recording head 30. On the magnetic display sheet 10, microcapsules 15 that develop color in response to magnetism are applied and fixed over the entire surface. The microcapsule 15 is composed of a high-viscosity liquid and a spherical shell that holds the liquid tightly, and substantially black magnetic particles and substantially white non-magnetic particles are dispersed in the liquid. For example, black iron oxide (FeO) particles having a particle size of 0.1 to 5 μm are used as magnetic particles, and non-magnetic particles have a particle size of 0.1 μm.
White titanium oxide particles of 1 to 5 μm are used. Also,
As the high-viscosity liquid, an aqueous liquid, an oil or fat, an organic solvent including a surfactant-based solvent, or the like is used. Gelatin is mainly used as a material of the spherical shell, and the particle size of the microcapsules 15 is 1
It is distributed in the range of 00 to 1000 μm.

The microcapsules 15 are kneaded with a binder 14 made of a highly transparent synthetic rubber-based adhesive or the like, and applied to a substrate 11 made of a transparent material such as polyethylene terephthalate.
A μm capsule coating layer 12 is formed.

On the back surface of the capsule coating layer 12, a protective sheet 13 made of, for example, a polypropylene long-fiber nonwoven fabric is adhered so as to have a thickness of, for example, 300 to 1000 μm.
Seat running is facilitated.

On the other hand, the recording head 30 has a box-shaped yoke 39 made of a high-permeability material, a magnetic core 37 made of a high-permeability material erected inside the yoke 39, and an electromagnetic core mounted on the magnetic core 37. And a plurality of magnetic cores 37 and electromagnetic coils 38 corresponding to the plurality of print dots. The magnetic core 37 is formed in a columnar shape, the diameter of the tip portion is formed smaller than the diameter of the middle portion, and a tapered portion whose diameter changes linearly is formed on the way.

A number of circular gap holes are formed in the printing surface 39a of the yoke 39, and the tip of the magnetic core 37 is positioned at the center of each gap hole, and a gap exists between the magnetic core 37 and the gap hole. As a result, a leakage magnetic field is generated. When the electromagnetic coil 38 is selectively energized in response to a print signal, a magnetic field is generated along the axial direction of the magnetic core 37 and passes through a magnetic circuit composed of the magnetic core 37, a gap, and a yoke 39. A recording magnetic field is generated toward the sheet 10.

Next, the principle of magnetic recording / display and erasure will be described. When the recording head 30 is brought close to the surface of the magnetic display sheet 10 where the substrate 11 is located, and a recording magnetic field is generated based on a print signal, the magnetic particles dispersed in the microcapsules 15 are attracted to the substrate 11 and the pressure is reduced. Thereby, the non-magnetic particles move to the protective sheet 13 side.
Then, when viewed from the front side of the magnetic display sheet 10, the portion to which the recording magnetic field is applied is observed to have a substantially black color. By applying the magnetic field in a dot matrix using the recording head 30, characters and symbols can be displayed. Can be recorded.

Next, when the erasing head 20 is brought close to the back side of the magnetic display sheet 10, that is, the side where the protective sheet 13 is located, the magnetic particles dispersed in the microcapsules 15 are attracted to the protective sheet 13 side, and the pressure is reduced. As a result, the non-magnetic particles move toward the base 11. Then, when viewed from the front side of the magnetic display sheet 10, the portion to which the erasing magnetic field is applied becomes substantially white, and the erasing magnetic field is uniformly erased by applying the erasing magnetic field to the entire sheet width.

As the above-mentioned high-viscosity liquid in the microcapsule 15, a liquid having a predetermined viscosity is selected in order to maintain a display state of the magnetic particles moved to the back side or the front side by applying a magnetic field. That is, if the viscosity of the liquid is low, the display state is prevented from being disturbed by the particles that have once moved to the front side or the back side settling or moving due to vibration or the like. Therefore, the above-described recording head 3
The magnetic attraction force in the zero and erasing heads 20 needs to be greater than the yield value due to the viscosity of the liquid, and thereby writing and erasing of a display are performed.

Next, the operation of the entire apparatus will be described. Referring to FIGS. 1 and 2, first, before printing is started, the magnetic display sheet 10 is circulated at a constant speed and the erase head 20 is rotated.
To erase the entire surface. Next, a print signal is received from an external host device, and each time the development of image data for one print line is completed, the recording head 30 is moved for several milliseconds to several hundred milliseconds while moving in the sheet width direction. The magnetic printing is performed by applying the pulse current described above and applying a dot matrix magnetic field to the surface of the magnetic display sheet 10.

When printing of one line is completed, the magnetic display sheet 10 is moved by a predetermined feed pitch and stopped, and then printing is performed based on the image data developed for the next printing line. Thus, the development of the image data, the recording head 30
The image of one sheet is formed while repeating the serial printing and the intermittent feeding of the magnetic display sheet 10.

Next, when printing a new image, the magnetic display sheet 10 is circulated at a constant speed to erase the entire surface by the erasing head 20, and then the recording head 3 is printed.
Performs serial printing with 0.

FIG. 4 is a configuration diagram showing various examples of the erasing head 20. First, in FIG. 4A, the erasing magnet 20a
Are made of planar permanent magnets, and the polarity is alternately reversed along the transport direction of the magnetic display sheet 10. Erase magnet 2
A film 20c having a smooth surface is stuck on the surface of Oa, and portions protruding from the upstream end and the downstream end of the erasing magnet 20a are bent inward at an angle of about 45 degrees.

The erasing magnet 20a is magnetized such that the N and S poles are periodically arranged at a predetermined pitch, and the magnetizing pitch is formed so as to gradually decrease from the center toward the end. With such an arrangement, the magnetic field intensity distribution at the sheet contact surface is formed to be weaker at the end portion than at the center portion, and the erasing magnetic field is gradually attenuated especially when the magnetic display body is separated from the contact surface. In addition, the wraparound of the magnetic field to the side in the transport direction at the end of the erasing magnet 20a is reduced, so that erasing unevenness can be eliminated and erasing characteristics can be improved.

Further, since the polarities of the permanent magnets are alternately reversed, the magnetic particles in the microcapsules 15 move greatly as the magnetic display sheet 10 moves. Therefore, the fluidity of the high-viscosity liquid in the capsule also increases, and the erasing characteristics can be greatly improved.

Next, in FIG. 4 (b), the erase magnet 20a
The planar display device is configured such that a planar and flexible permanent magnet is supported by a support member 21, and the polarity is alternately reversed along the transport direction of the magnetic display sheet 10. The support member 21 has a flat portion in contact with the magnetic display sheet 10 and approximately 4
And an inclined portion extending in the direction of 5 degrees.
a is bent along the shape of the support member 21. A film 20c having a smooth surface is provided on the surface of the erase magnet 20a.
Is affixed.

The erasing magnet 20a is magnetized such that the N pole and the S pole are periodically arranged at the same pitch in the plane portion and the inclined portion of the support member 21. With such an arrangement, the magnetic field intensity distribution at the sheet contact surface is formed to be weaker at the end portion than at the center portion, and the erasing magnetic field is gradually attenuated especially when the magnetic display body is separated from the contact surface. In addition, there is no influence of the magnetic field wrapping around the side of the end of the erasing magnet 20a in the transport direction, so that erasing unevenness can be eliminated and erasing characteristics can be improved.

Next, in FIG. 4C, the erasing magnet 20a
The planar display device is configured such that a planar and flexible permanent magnet is supported by a support member 21, and the polarity is alternately reversed along the transport direction of the magnetic display sheet 10. The support member 21 is formed of a metal having high magnetic permeability such as iron and has a U-shaped cross section. The length in the transport direction is about half the length of the erasing magnet 20a.
The upper and lower ends of Oa remain flexible. Erase magnet 2
A film 20c having a smooth surface is affixed to the surface of Oa, and portions protruding from the upstream end and the downstream end of the erasing magnet 20a are configured to bend inward.

The erasing magnet 20a is magnetized such that the N pole and the S pole are periodically arranged at an equal pitch. With such an arrangement, the magnetic flux on the support member 21 side of the erasing magnet 20a increases due to the high magnetic permeability of the supporting member 21 in the portion of the erasing magnet 20a supported by the support member 21, and accordingly, the erasing magnet 20a on the magnetic display sheet 10 side. The magnetic flux to
The magnetic field is stronger than the upstream end and the downstream end of the erasing magnet 20a. Therefore, the magnetic field strength distribution at the sheet contact surface is weaker at the end than at the center. Therefore, when the magnetic display is separated from the contact surface, the erasing magnetic field is gradually attenuated, and the erasing characteristics can be improved.

In FIG. 4D, the erasing magnet 20a is formed of a planar permanent magnet, and the polarity is alternately reversed along the transport direction of the magnetic display sheet 10. Erase magnet 20a
A film 20c having a smooth surface is adhered to the surface of the erasing magnet 20a, and portions of the erasing magnet 20a projecting from the upstream end and the downstream end are bent inward at an angle of about 45 degrees.

The erasing magnet 20a is magnetized such that the N pole and the S pole are periodically arranged at the same pitch (P), and further cuts the end magnetic pole at the downstream end in the sheet conveying direction to thereby form the N pole or S pole. The pole width (L) is shorter than the magnetized pitch (L <P). With such an arrangement, the magnetic field intensity distribution at the sheet contact surface is formed to be weaker at the end portion than at the center portion, and the erasing magnetic field is gradually attenuated especially when the magnetic display body is separated from the contact surface. In addition, the wraparound of the magnetic field to the side in the transport direction at the end of the erasing magnet 20a is reduced, so that erasing unevenness can be eliminated and erasing characteristics can be improved.

In the present embodiment, the structure of both the upstream end side and the downstream end side of the erasing magnet is formed symmetrically. However, the present invention is not limited to this, and only the downstream end side of the erasing magnet is provided. It may be one satisfying the present invention.

[0045]

As described in detail above, according to the present invention, when the magnetic display body moves away from the erasing means, the erasing magnetic field gradually decreases. Therefore, the time change of the erasing magnetic field applied to the magnetic display body is reduced, and the influence of the feeding unevenness and the intermittent feeding can be reduced.

Further, since the polarities of the permanent magnets are alternately reversed, erasure unevenness is small and erasure with high contrast can be realized.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an electronic information display device according to the present invention.

FIG. 2 is a partial perspective view showing an internal configuration of the electronic information display device of FIG.

FIG. 3 is a partial cross-sectional view showing the structures of a magnetic display sheet 10 and a recording head 30.

FIG. 4 is a configuration diagram showing various examples of an erasing head 20.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 housing 2 display window 10 magnetic display sheet 11 base 12 capsule coating layer 13 protective sheet 14 binder 15 microcapsule 20 erase head 22 full surface write head 30 recording head 31 carriage 32 guide shaft 33 belt 37 magnetic core 38 electromagnetic coil 39 yoke 50, 51, 52, 60 Roller 53, 54 Pressing roller

Claims (2)

[Claims] 1. A magnetic display which can be written and erased magnetically, transport means for transporting the magnetic display, and a recording magnetic field applied to the magnetic display based on an external print signal. Recording means for forming a still image, and an erasing means for erasing a recorded image by generating an erasing magnetic field from the erasing surface and having a facing surface facing the magnetic display. An electronic information display device, characterized in that the magnetic field intensity distribution on the surface is formed so that the downstream end portion of the magnetic display body is weaker than the central portion of the opposing surface. 2. An electronic information display device according to claim 1, wherein said erasing means is constituted by a planar permanent magnet whose polarity is alternately reversed along the transport direction of the magnetic display. .