JP3693093B2 - Display medium and writing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display medium that can rewrite an image (including characters and graphics) and a writing device that writes the image on the display medium.
[0002]
[Prior art]
Consumption of a large amount of paper, especially in offices, has become a problem due to destruction of forest resources, which are raw materials for paper pulp, waste disposal, and environmental pollution caused by incineration. However, with the spread of personal computers and the development of the information society including the Internet, the consumption of paper as a so-called short-lived document for the purpose of temporary browsing of electronic information tends to increase more and more. Realization of a rewritable display medium replacing paper is desired.
[0003]
Paper is 1) bright, high-contrast, reflective full-color display, easy to read, large amount of information display 2) light and thin, flexible structure, easy posture, favorite lighting 3) The display has memory characteristics, can display and store information without a power supply, and is flickerless, with little eye fatigue. 4) Low cost, It has an excellent information display characteristic that the display is easy to obtain due to the simultaneous display of multiple sheets, easy comparison and browsing of information, etc. This is a renewal of the information displayed on the display It is a factor that causes the act of browsing after printing on paper. Therefore, in addition to the rewritability for realizing resource saving and waste saving, it is necessary for the display medium instead of paper to have the above-mentioned characteristics unique to paper.
[0004]
Therefore, in order to realize a display medium having a form like paper and being easy to use, it has been considered to separate the display medium from a drive circuit for driving the display medium.
[0005]
In Japanese Patent Laid-Open No. 2-254420, as shown in FIGS. 5A and 5B, the matrix liquid crystal panel 1 and the drive circuit 4 are configured separately, and the matrix liquid crystal panel 1 includes column electrodes 2 in the periphery. In addition, the contacts 2a and 3a of the row electrode 3 are formed, and the drive circuit 4 is provided with an electrode 5 to which the contacts 2a and 3a are connected, so that the matrix liquid crystal panel 1 can be attached to and detached from the drive circuit 4. It has been shown.
[0006]
JP-A-6-67141 discloses on both sides of a light modulation member 7 such as a composite film of a polymer material and a low molecular liquid crystal or a composite film of a polymer liquid crystal and a low molecular liquid crystal as shown in FIG. Although the recording medium sheet 9 provided with the protective layers 8a and 8b is not shown in FIG. 6, the recording medium sheet 9 is initialized by passing it through a roll connected to an initialization power source to be in a light transmission state, and then a charge corresponding to the image information. By passing a voltage between the drum on which the pattern is formed and the transfer roller and applying a voltage corresponding to the image information to the recording medium sheet 9, the alignment state of the liquid crystal molecules in the light modulation member 7 is changed according to the image information. Shows changing and writing the image.
[0007]
In order to prevent the high-voltage electrode portion from being exposed to the outside, it is desirable to send power without contact. In a non-contact type IC card or the like, a power supply voltage and a signal are separated and extracted from a high-frequency pulse by one coil using electromagnetic induction. However, since the data capacity that can be supplied by one coil is limited, the data capacity required for the memory card is sufficient, but large-capacity image information cannot be transferred at high speed.
[0008]
Japanese Patent Laid-Open No. 6-187514 discloses an IC memory card system that includes a main unit and an IC memory card that transfers data between the main unit and the main unit without contact with the main unit. A power supply circuit for supplying power to the IC memory card and a coil for supplying power to the IC memory card by induced electromotive force are provided. The IC memory card is inductively coupled with the coil of the main unit and supplied from the power supply circuit. In addition to inductive coupling means comprising both coils, means for non-contact coupling and data transfer to the main unit and the IC memory card are provided. It is shown to be provided.
[0009]
[Problems to be solved by the invention]
However, in the display device shown in FIG. 5, the matrix liquid crystal panel 1 is an m × n matrix, and the matrix liquid crystal panel 1 needs m + n contacts. For example, in the case of a VGA panel, 640 + 480 = 1120. Such a large number of contact points are required, so that it is not easy to align the connection, and it is necessary to sandwich the contacts with a strong force. As a result, there is a problem that it is not easily removable, and is vulnerable to dirt such as contact dirt and metal powder. In order to avoid this, even if a part of the drive circuit is provided to the matrix liquid crystal panel 1, a connector is necessary, and the difficulty of attaching / detaching is not changed.
[0010]
Further, in the method disclosed in Japanese Patent Laid-Open No. 6-67141, it is necessary to charge the recording medium sheet 9 shown in FIG. 6 over the entire surface. When a liquid crystal panel without a polarizing plate is used separately, fingerprints, dirt, etc. In addition, there is a problem that the charging of the sheet surface is influenced by moisture or the like. In addition, in the method of dimming using polarized light such as a ferroelectric liquid crystal, it is necessary to make a close contact with the polarizing plate after writing each time, and the ferroelectric liquid crystal is weak against mechanical deformation and does not return to its original state when broken. There's a problem. In addition, when viewed without a close contact, an air layer is interposed between the liquid crystal panel and the polarizing plate, the reflectance decreases, and a sheet-like display medium cannot be obtained. In addition, because the DC electric field is applied, the space charge in the liquid crystal panel is biased to cause burn-in, the voltage drop on the plastic substrate is larger than the liquid crystal layer, and a high voltage is required, and the writing device is complicated There are problems such as enlargement.
[0011]
Further, according to the method disclosed in Japanese Patent Laid-Open No. 6-187514, a power supply stabilizing device may be thin and small if it is a low-voltage microcurrent drive chip such as an IC memory card, but a display medium such as a memory liquid crystal is used. Since the power supply stabilizing device that stabilizes the high voltage to be driven is enlarged, there is a problem that it cannot be mounted on a thin display medium.
[0012]
Thus, in order to realize a user-friendly display medium having a form such as paper, the present invention provides a connection position between the display medium and a writing device for writing an image on the display medium. The display medium can be easily attached to and detached from the writing device, the high-voltage electrode part can be structured not to be exposed to the outside, large-capacity image information can be transferred at high speed, and a large-sized device can be displayed thinly. There is no need to mount it on a medium.
[0013]
[Means for Solving the Problems]
The writing device of the present invention comprises:
A writing device for writing an image on a display medium in which an image is written by light and the image can be rewritten ,
A light emitting display element for writing on which an image to be written on the display medium is displayed , a ferromagnetic ring, an exciting coil wound around the ferromagnetic ring, and a drive pulse supply connected to the exciting coil characterized in that it comprises a circuit.
[0014]
The display medium of the present invention is
A display medium in which an image is written by light and the image can be rewritten ,
A mark portion to be set in ferromagnetic ring provided on the writing device for writing an image on the display medium, characterized in that it comprises a secondary coil wound around the mark portion.
[0015]
[Action]
In the display medium writing system composed of the writing device and the display medium configured as described above, the exciting coil wound around the ferromagnetic ring provided in the writing device and the winding around the mark portion of the display medium. The rotated secondary coil constitutes a dielectric coupling means, and the drive pulse from the drive pulse supply circuit of the writing device is supplied to the display medium by this dielectric coupling means. Therefore, the connection between the writing device and the display medium only needs to set the mark portion of the display medium on the ferromagnetic ring of the writing device, and the alignment of the connection between both becomes easy, and the display medium is connected to the writing device. On the other hand, it can be easily detached and the high voltage electrode part can be structured not to be exposed to the outside.
[0016]
In addition, by setting the mark portion of the display medium in the ferromagnetic ring of the writing device in this way, the receiving side depends on the location and angle as in the case where the antenna receives electromagnetic waves spatially radiated from the antenna. The power received by the display medium does not change or becomes weak, and the display medium can receive power directly and stably from the writing device.
[0017]
Further, by providing a large number of ferromagnetic rings 12 in the writing device, winding exciting coils on each of them, providing a large number of mark portions on the display medium, and winding a secondary coil around each of them. , Not only drive pulses but also power supply voltage and data can be easily supplied from the writing device to the display medium, high-capacity image information can be transferred at high speed, and the power supply stabilizes the high voltage There is no need to mount a large device such as a stabilizing device on a thin display medium.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
1 and 2 show a first embodiment of a writing apparatus and a display medium according to the present invention.
[0019]
In this embodiment, the writing device 10 is provided with a light emitting display element 11, a ferromagnetic ring 12, and a drive pulse supply circuit 14, and an excitation coil 13 is wound around the ferromagnetic ring 12 to drive the drive pulse supply circuit 14. Are connected to the exciting coil 13. The ferromagnetic ring 12 is openable and closable.
[0020]
The light-emitting display element 11 may be any element that emits light that changes the impedance of a photoconductive layer 23 of the display medium 20 described later, such as a transmissive liquid crystal display element or an EL element.
[0021]
The ferromagnetic ring 12 may be any steel ring core, ferrite core, dust core, etc., as long as it can confine magnetic flux inside. However, the loss due to eddy current is small and the magnetic permeability is high. A ferrite system that requires a small number of windings is desirable.
[0022]
As shown in FIG. 1E, the display medium 20 is formed with a hole 28 as a mark portion, and a secondary coil 29 is wound around the hole 28. The secondary coil 29 is formed by attaching a wire or etching a metal pattern.
[0023]
In this embodiment, the display medium 20 is a display element capable of storing a display image in which pixels are addressed by light.
[0024]
For example, as shown in FIG. 1C, the display medium 20 includes a photoconductive layer 23, a light shielding layer between a transparent substrate 21 on which a transparent electrode 22 is formed and a transparent substrate 27 on which a transparent electrode 26 is formed. A layer 24 and a liquid crystal layer 25 are laminated, and light from the light emitting display element 11 of the writing device 10 is irradiated onto the photoconductive layer 23 to change the impedance thereof, thereby addressing the pixels. It is formed of cholesteric liquid crystal, displays a specific color by selective reflection of cholesteric liquid crystal, and stores and holds an image by the memory property of the cholesteric liquid crystal in a planar state or a focal conic state.
[0025]
The photoconductive layer 23 may be a-Si or an organic photoconductor, but when the transparent substrate 21 is plastic, the organic photoconductor is more preferable because of the deposition temperature.
[0026]
The liquid crystal layer 25 is not limited to the one that displays by selective reflection with cholesteric liquid crystal as long as it can control reflection by changing the applied voltage due to the impedance change of the photoconductive layer 23 and has a memory property. Or a smectic liquid crystal. Further, not only reflection but also a scattering mode may be shown. Further, absorption or polarization may be used, but in that case, a reflective layer such as a dielectric multilayer film or a polarizing plate is further required. Further, the display layer may be formed by an electrophoretic capsule or the like instead of the liquid crystal layer.
[0027]
As shown in FIG. 2, the transparent electrodes 22 and 26 of the display medium 20 are connected to the secondary coil 29.
[0028]
In this embodiment, when an image is written on the display medium 20 and the display of the display medium 20 is changed, the ferromagnetic ring 12 of the writing device 10 is opened and the photoconductive layer 23 of the display medium 20 is written. The device 10 is set at an image forming position on the light emitting display element 11, and the ferromagnetic ring 12 is inserted into the hole 28 of the display medium 20 and closed.
[0029]
Then, a still image is displayed on the light emitting display element 11, and the photoconductive layer 23 of the display medium 20 is irradiated with light from the light emitting display element 11 as shown in FIG. The drive pulse from the pulse supply circuit 14 is boosted by the excitation coil 13 and the secondary coil 29 forming the dielectric coupling means 31 and supplied between the transparent electrodes 22 and 26 of the display medium 20.
[0030]
In this case, almost all the magnetic flux induced by the exciting coil 13 passes through the ferromagnetic ring 12 and crosses the secondary coil 29, and the exciting coil 13 and the secondary coil 29 pass through the ferromagnetic ring 12. , Electrically coupled strongly. Therefore, the driving pulse is stably and efficiently transmitted from the writing device 10 to the display medium 20.
[0031]
In this case, the driving frequency is determined in consideration of the coercivity of the ferromagnetic ring 12, the admittance of the display medium 20, the dielectric loss (tan δ), etc., and is approximately between several tens Hz to several MHz. .
[0032]
As in the example described above, it is desirable that the ferromagnetic ring 12 be openable and closable so as to be inserted into the hole 28 of the display medium 20 and closed. However, since the display medium 20 is thin, the ferromagnetic ring 12 is When the gap interval is small and the magnetic flux leakage is small, the ferromagnetic ring 12 may not be openable and closable. Further, by embedding a ferromagnetic material in the display medium 20 and connecting it to the ferromagnetic ring 12, magnetic flux leakage can be reduced.
[0033]
The mark portion provided on the display medium 20 is not a hole but may simply indicate a position to be set on the ferromagnetic ring 12 of the writing device 10, and the mark portion may be sandwiched between the ferromagnetic ring 12. Good.
[0034]
[Second Embodiment]
3 and 4 show a second embodiment of the writing device and the display medium of the present invention.
[0035]
In this embodiment, not only the driving pulse but also the power supply voltage and write data are written by the dielectric coupling between the excitation coil wound around the ferromagnetic ring of the writing device and the secondary coil on the display medium. In this case, the data is supplied to and transmitted from the display medium.
[0036]
In this embodiment, as shown in FIG. 4, the display medium 20 is provided with a matrix display unit 40, and accordingly, a common driver 51, a segment driver 52, a drive pulse generation circuit 54, a power supply circuit 55, and data A demodulation circuit 56 is provided.
[0037]
For example, as shown in FIG. 3, the matrix display unit 40 includes a light absorption layer 43 and a liquid crystal layer 44 between a substrate 41 on which row electrodes 42 are formed and a transparent substrate 46 on which column electrodes 45 are formed. It is a reflection type liquid crystal display element formed by lamination.
[0038]
The common driver 51 and the segment driver 52 are configured as an IC (integrated circuit). The power supply circuit 55 obtains a DC low voltage power supply voltage for driving the IC. The data demodulating circuit 56 demodulates the data modulated by the high frequency pulse transmitted from the writing device 10 and sends it to the common driver 51 and the segment driver 52. The drive pulse generation circuit 54 sends drive pulses to the common driver 51 and the segment driver 52.
[0039]
The writing device 10 is provided with a drive pulse supply circuit 14, a power supply circuit 15 and a data modulation circuit 16. The drive pulse supply circuit 14 transmits drive pulses to the drive pulse generation circuit 54 of the display medium 20, and the power supply circuit 15 transmits AC power supply pulses to the power supply circuit 55 of the display medium 20. The power supply circuit 55 rectifies and smoothes the AC power supply pulse to obtain a DC low voltage power supply voltage for driving the IC. The data modulation circuit 16 modulates write data with a high frequency pulse and transmits it to the data demodulation circuit 56 of the display medium 20.
[0040]
In this embodiment, as shown in FIG. 3, the writing device 10 is provided with a large number of ferromagnetic rings 12, and an exciting coil 13 is wound around each. In addition, a large number of holes 28 are formed in the display medium 20, and a secondary coil 29 is wound around each of the holes. A large number of ferromagnetic rings can be used as a binder for binding a plurality of display media 20.
[0041]
The many ferromagnetic rings are composed of a drive pulse supply ring, a power supply ring, and a data supply ring. However, the power supply ring and the data supply ring may be combined. In that case, the display medium 20 is provided with a circuit for separating the AC power supply pulse and the modulated data from the AC pulse transmitted through the combined ferromagnetic ring.
[0042]
When a plurality of display media are set and used in a binder, a switch or the like may be attached to the display media to switch the supply of drive pulses or the like to each display medium. Further, an address may be set in the display medium by using a dip switch or the like, and the active display medium may be switched by a signal.
[0043]
In this embodiment, by providing a plurality of ferromagnetic rings, not only the driving pulse but also the power supply voltage and the write data can be transmitted from the writing device 10 to the display medium 20. Since there is little leakage of magnetic flux from the ring, crosstalk between the transmission channels is reduced.
[0044]
【The invention's effect】
As described above, according to the present invention, when the display medium and the writing device for writing an image on the display medium are separated from each other, it is easy to align the connection between the display medium and the writing device. It can be easily detached, the high voltage electrode portion can be structured not to be exposed to the outside, large-capacity image information can be transferred at high speed, and there is no need to mount a large device on a thin display medium.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment of a writing device and a display medium according to the present invention.
FIG. 2 is a diagram illustrating a power feeding circuit according to the first embodiment.
FIG. 3 is a diagram showing a second embodiment of the writing device and the display medium of the present invention.
FIG. 4 is a diagram illustrating a power feeding circuit according to a second embodiment.
FIG. 5 is a diagram showing a conventional matrix liquid crystal panel system.
FIG. 6 is a diagram showing a recording medium sheet used in a conventional image writing system.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Writing apparatus 11 ... Light emission type display element 12 ... Ferromagnetic ring 13 ... Excitation coil 14 ... Drive pulse supply circuit 15 ... Power supply circuit 16 ... Data modulation circuit 20 ... Display medium 28 ... Hole (mark part)
29 ... Secondary coil 40 ... Matrix display 54 ... Drive pulse generation circuit 55 ... Power supply circuit 56 ... Data demodulation circuit

Claims (5)

A writing device for writing an image on a display medium in which an image is written by light and the image can be rewritten,
A light-emitting display element for writing on which an image to be written on the display medium is displayed, a ferromagnetic ring, an exciting coil wound around the ferromagnetic ring, and a drive pulse supply connected to the exciting coil And a writing device. A display medium in which an image is written by light and the image can be rewritten,
A display medium comprising: a mark portion set on a ferromagnetic ring provided in a writing device for writing an image on the display medium; and a secondary coil wound around the mark portion. The writing device according to claim 1.
The writing device includes a plurality of ferromagnetic rings, each having the exciting coil wound thereon, and a dielectric between the exciting coils and the secondary coils provided on the display medium. A writing apparatus characterized in that, by coupling, the drive pulse from the drive pulse supply circuit is boosted and supplied to the display medium. The writing device according to claim 1.
The writing device includes a plurality of ferromagnetic rings, each having the exciting coil wound thereon, and a dielectric between the exciting coils and the secondary coils provided on the display medium. A writing apparatus characterized in that a power supply voltage and data are supplied to the display medium together with drive pulses from the drive pulse supply circuit by coupling. The display medium of claim 2,
A display medium, wherein the display medium is capable of storing an image.

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