JPH02280116A - information storage device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a device for reversibly and optically storing an extremely large amount of data, and particularly to an information storage device using a polymeric liquid crystal composition.

[Prior Art] Optical storage systems are currently in practical use as they have a large capacity and are excellent in random access. There are many different ways to do this, and for playback only, digital audio discs (C
O) and laser video discs (LD) have been put into practical use. Write-once optical discs (
WO), optical carts (OC) are known, and some use phase change of a metal thin film, and others use a pit type of organic dye.

Furthermore, research on rewritable optical disks is progressing, and efforts are being made to put those using the magneto-optical effect and those using phase change into practical use. Among these, polymer liquid crystals have also been proposed as information storage media (Japanese Patent Application Laid-Open No. 10930-1983)
No. 1, JP-A-59-35989, JP-A-62-
154340), in which the recording method involves changing the helical pitch length of the cholesteric polymer liquid crystal;
Alternatively, a method has been proposed in which the light reflectance is multivalued by forming pits in a non-oriented state (Japanese Patent Laid-Open No. 62
In addition to information recording media, display devices using polymer liquid crystals have also been proposed. (Unexamined Japanese Patent Publication No. 62-2785
(No. 29, Japanese Unexamined Patent Publication No. 62-2785:10) These are capable of storing large amounts of data and have excellent characteristics, but the recording wavelength of magnetic recording is 0.1 The current situation is that it is possible to hold a large amount of horse mackerel, so it can no longer be said that the capacity is sufficiently large.

Holographic memory has been proposed as a possibility for ultra-large capacity storage using optical recording [P.J.
Van Harden “Applied Optics J (
P. J. van Heerden, Appl.

2, p. 393 (1963)].

However, these could not be used practically because there were no reversible photosensitive materials capable of recording ultra-high density holograms.

Recently, a reversible photosensitive material suitable for such purposes using a photoisomerization reaction of polymeric liquid crystals has been reported. (Unexamined Japanese Patent Publication No. 63-87626, Unexamined Japanese Patent Publication No. 62-19
1826 Publication) [Problems to be Solved by the Invention] However, since the above-mentioned conventional example uses a photoisomerization reaction, it has a drawback that writing speed and erasing speed are slow. Furthermore, in the conventional example described above, when recording and reproducing extremely large amounts of data, the recording speed and reproducing speed are not sufficient, which has the disadvantage of limiting the performance of the input/output control device in inputting and transferring data.

The purpose of the present invention has been made in order to improve the drawbacks of the conventional technology, and it is possible to record an extremely large amount of data on an information storage medium at high speed using holograms, and also to enable the recorded extremely large amount of data to be recorded at high speed. The object of the present invention is to provide an information storage device that enables playback.

[Means for Solving the Problems] That is, the present invention provides a means for irradiating a laser beam, a means for separating the laser beam into a reference beam and a recording beam, and a plurality of methods for intensity modulating the separated recording beam. A means for providing bit information, a means for recording interference between a reference light made of a polymer liquid crystal composition and a recording light, and a means for receiving diffracted light generated when the reference light is irradiated. This is an information storage device characterized by:

The present invention will be explained in detail below.

According to the information storage device of the present invention, means for irradiating laser light, means for separating the laser light into reference light and recording light,
Means for imparting multiple bits of information consisting of intensity modulation to the separated recording light, means for recording interference between the reference light and recording light made of a polymeric liquid crystal composition, and diffracted light generated when the reference light is irradiated. By providing a means consisting of multiple photodetectors that receive light, it becomes possible to record extremely large amounts of data using holograms at high speed on a storage medium made of a polymeric liquid crystal composition, and it also becomes possible to record extremely large amounts of data at high speed. It is possible to reproduce it.

Next, the information storage device of the present invention will be explained in detail using FIG. FIG. 1 is a schematic diagram showing an example of an information storage device of the present invention. In the figure, first, the intensity and pulse width of the laser light source 102 are controlled by a laser light source driving device lot, thereby modulating the laser light for recording or reproduction. A semiconductor laser is most suitable as a laser light source capable of such modulation, and a single transverse mode semiconductor laser with a long coherence lens length is particularly selected.

The obtained laser beam is made into parallel light by the collimator lens 103, and the recording beam +1 is converted by the half mirror 1Ω4.
9 and a reference beam 120.

The recording light 119 is focused by the condenser lens 109 onto the polymer liquid crystal composition photoreceptor layer 114 on the information storage medium 116 . At this time, the recording light 119 is transmitted by the input data signal generated from the input data transfer device R110 for recording.
A shutter array drive circuit 111 generates a drive signal for the shutter array 112, and provides the shutter array 112 with input data based on density changes.

For the shutter array 112, it is possible to use a ferroelectric crystal, a ferroelectric ceramic such as PLZT, a ferroelectric liquid crystal such as the liquid crystal 9, or the like. In particular, shutter arrays using surface-stabilized ferroelectric liquid crystals can be driven at high speed.
Moreover, it is possible to output extremely large amounts of data using its memory properties.

The recording light subjected to density modulation by the shutter array is focused by a mirror 113 onto a polymer liquid crystal composition photoreceptor layer 114 of an information storage medium 116.

On the other hand, the reference beam 1 separated by the half mirror 104
The light beam 20 is reflected by a mirror 105 and further focused by a condenser lens 108 at the same position as the recording light. The focused recording light 119 and reference light 120 cause interference and are recorded in the oriented polymer liquid crystal composition of the polymer liquid crystal composition photoreceptor layer 114 as an interference stripe holographically as a change in refractive index.

At this time, autofocus is performed to partially detect the reflected light so that the recording section is irradiated with a constant laser power, thereby making stable recording usable.

The polymeric liquid crystal composition photoreceptor layer 114 used in the information storage medium 116 is made of a polymeric liquid crystal compound and a light absorber, and is obtained by coating it on the substrate 115 and then subjecting it to alignment treatment.

Specific examples of the polymer liquid crystal compound in the present invention and the polymer liquid crystal compound used for products include the following.

(In the following formulas (1) to (13), 15>n≧1.) (L) (!2) (]4) (In the following formulas (14) to (17), p=5 to 1000° pI+p2: 5-1000°q=1-16°Q+=1-16°Q2=.

CH:1 →C112-C→r (In the following formulas (18) to (46), * indicates asymmetric carbon center Show.

n=5 to 1000.

(-, -=2~10) (2ri(kai,=2~l5) (2 pieces) (Kou2=2~Is) (m,=2~!8+) (x+y=1゜q=l~ 1G, P2= l~l5) (Otori2=2~1s) (@, =2~Is) (m2=2~+5°x+y=1) (x+y=1.■2=2~15) (x+y= 1) (x+y=1.a+t=2~l5) (x+y=1.m2=2~+5) (recommended=1~5) (I15=0~5) r (5ri (hereinafter, 16 is 1~18 ) (β2=5-18) P-decyloxybenzylidene-P'-amino-2-methylbutylcinnamate (DOBAMBC) (60) P-hexyloxybenzylidene=P'-amino-2-chloropropylcinnamate IIOBACPC The polymeric liquid crystal compound can be used in combination with a low molecular weight liquid crystal to adjust its phase transition temperature.

A specific example of a low molecular weight liquid crystal is the following P-decyloxybenzylidene-P'-amino-2-methylbutyl-α-cyanocinnamate (DOBAMBCC).
) can be mentioned.

P-tetradecyloxybenzylidene-P'-amino-2
-Methylbutyl-α-cyanosinname)-(TDOB
To 8MB: C) (2-methylbutyl) ester P-octyloxybendisodene-P'-amino-2-
Methylbutyl-α-chlorocinnamate (OOBAM
B(:C)-4'-octylaniline (MBRA oxybiphenyl-4-carboxylate P-octyloxybenzylidene-P' to amino-2-methylbutyl-α-methylcinnamate (1) butyl) biphenyl-4' -carboxylate 4-(2″-methylbutyl)phenyl-4-(4″-methylhexyl)biphenyl-4′-carboxylatebutyl) biphenyl-4′-carboxylate 4-(2′-(pro-and-ruoxy)propyl) )oxyphenyl-4-(desyloxy)biphenyl-4'-carboxylatebutyl) biphenyl-4'-carboxylate (4'-(4-hexyloxy)phenyloxycarbonyl)phenyl-p-(4''-methylhexyloxy) )
Benzoate Direct Red 28 Direct Violet 12 Furthermore, write with a laser beam, etc.

In the case of erasing, the sensitivity can be improved by adding a laser light absorbing compound to the photoreceptor layer of the polymeric liquid crystal composition.

Added to polymer liquid crystal layer Examples of laser light absorbing compounds include:

Shown below Examples include:

Direct Blue + Direct Blue Is Direct Blue 98 Direct Blue 151 Direct Red 81 Direct Yellow 44 Direct Yellow 12 Direct Orange :19 N■2 υ υ11 υ N■2 Disperse Red Disperse lue Ci'048 AsF,e CRO,e Also, semiconductor As near-infrared absorbing dyes suitable for recording, reproducing, and erasing using laser light, the following are used.

Organic macrocyclic dyes that can be added to polymeric liquid crystal compounds to significantly lower the glass transition point (Tg) and melting point (Tm) and do not cause an increase in mobility that would reduce the liquid crystal phase include: There are azaannulenes, annulenes, etc., and an alkyl substituent is provided for solubility, but other substituents may be provided to the extent that solubility is not inhibited.

More specifically, phthalocyanines, naphthalocyanines, tetrabenzoporphyrins, and other substituted and unsubstituted porphyrins are used.

Particularly effective examples include phthalocyanine and naphthalocyanine represented by the following general formula (I).

(General formula (I) middle code is shown.

[However, R3-R2゜ is a hydrogen atom, and has 4 to 20 carbon atoms.
represents a straight-chain or branched alkyl group, alkoxy group, alkenyl group, or a substituent selected from the following.

SiQ+QzQ3 5Q4 -　COQ.

-C00Q6 NQtQa (Q, ~Q6 is a hydrogen atom, a linear or branched alkyl group or alkenyl group having 1 to 2 carbon atoms; M is Ge, Sn, transition metal, All, Ca, I
n, indicating alkaline earth metals, lanthanide metals, aftinite metals, and their oxides, halogen compounds, or alkoxy compounds) When performing optical recording, the use of a semiconductor laser with a wavelength from near infrared to red visible is used for recording and reproduction. miniaturization of equipment,
Naphthalocyanines are particularly excellent as soluble organic macrocyclic dyes that can be used in this wavelength range, which is important for improving performance.

In particular, those represented by general formula (II) have excellent solubility and are therefore suitable for the storage medium of the present invention.

(Xsn)b [M in general formula (+1): Gc, Sn, 3-transfer metal, ACCa, I
n, alkali metal, lanthanide metal or aftinite metal X: halogen group, alkyl group, carboxyl group, alkoxy group, ether group or alkenyl group, etc. ether group or alkenyl group, etc.

a to d: O to 4.

(However, a+b+c+d≧1),] These compounds can be easily synthesized by the method disclosed in JP-A-61-90291.

Furthermore, other compounds that can be used as absorbers for semiconductor laser light include aminium salt compounds and diimonium salt compounds.

The aminium salt compound and diimonium salt compound used in the present invention each have the following general formula [ml [
IV] and [V].

General formula [I11] % formula % [ general formula [V,] - In the general formulas [ml, [IV] and [V] of -F, 11 to 810 are the same or different hydrogen atoms, or alkyl groups (e.g. Methyl group, ethyl group, n-propyl group, 1so-propyl group, n-butyl group, 5ec-butyl group, 1so-butyl group, t-butyl group, n-amyl group, t-amyl group, n-hexyl group , n-octyl group, t
-octyl group, C9-C1□ alkyl group, etc.)
and further includes other alkyl groups, such as substituted alkyl groups (e.g., 2-hydroxyethyl group, 3-hydroxypropyl group, 4-hydroxybutyl group, 2-acetoxyethyl group, carboxymethyl group, 2-carboxyethyl group, 3-carboxypropyl group, 2-sulfoethyl group, 3
-Sulfopropyl group, 4-sulfobutyl group, 3-sulfatepropyl group, 4-sulfnietratyl group, N-(
(methylsulfonyl)-carbamylmethyl group, 3-(acetylsulfamyl)propyl group, 4-(acetylsulfamyl)butyl group, etc.), cyclic alkyl groups (e.g.

cyclohexyl group, etc.), alkenyl group (vinyl group, allyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, todecynyl group, prenyl group, etc.), aralkyl group 2! (eg, benzyl group, phenethyl group, α-naphthylmethyl group, β-naphthylmethyl group, etc.), and substituted aralkyl groups (eg, carboxybenzyl group, sulfopencyl group, hydroxybenzyl group, etc.).

Y represents C- or -()-(t-), and this aromatic ring may be substituted with an alkyl group, a halogen group, or an alkoxy group.

80 is an anion, such as barchlorate, fluoroborate, iodide, chloride, bromide, sulfate, bariodide, p-toluenesulfate. Aminium salt compounds and diimonium salt compounds of these are disclosed in Japanese Patent Publication No. 43-25335, etc. It can be synthesized according to the synthesis method described in .

Next, representative examples of the aminium salt compound* (AM) represented by the general formula [ml, [IV]] are listed in Table 1 below.

Compound general formula %formula% ^Praise-lgo ^M-14 8M-1s table Kuy Σ + minutes stand (y top Kuy minutes + ÷ Kuto , kun stand ÷ Cll.

C11.

CH.

C. 11% C.J.

alls n-C=Hy iso-C. II.

-CJs n-Ca.

-CJs -CJq n-C. lI.

-CJIs t-C. II9 Ryu Eighty sFse cPo. .

SbFsθ AsF. .

CI! 04θ 8F. θ AsFa’ CI! 04.

cPo. .

AsF6.

SbF. θ RF4θ CIl, KyS Off.

cpo. ' Compound General formula % Formula % [ [ ] [ ] Next, representative examples of the diimonium salt compound (IM) represented by the general formula [V] are listed in Table 2 below.

table 1 to 1 1 to 2 1M-, 3 G4 G5 G6 G7 G8 G9 Between - Summer Seki-12 Thread! 8 C11.

C2 IIs C 2H.

zHs n-C311 iso-C3Ht -C4Hs n-C, II.

n−C<Is n-C4 IIs n-C. ll.

-Cls -C4Hs t-C4) 1s n-Cs)It:+ n-C6H+t AsF. θ CI! O, θ SbF. e ASF6θ cpo. e 8F4θ sF6e cpo. .

cpo. e AsF. e SbF6' RF. e CIi1C TOSO3e CI! 04θ AsF. θ cro. OAsF. θ General formula [1] 1M-19n-C+J□s ←←←SbF6θIM-
20 C2H,OH← ← ← SbF
6゜IM-21C2H,011← ← ←
CI! 04゜IM-22C,H,O)I ← ←
← NO:I.

IM-2: l C, H4011← ← ←
5bFs.

The above aminium salt compound (hereinafter referred to as AM compound)
and diimonium salt compounds (hereinafter referred to as IM compounds) have absorption in the near-infrared region, are useful as stable light-absorbing dyes, and are compatible or dispersible with polymeric liquid crystals.

Furthermore, metal chelate compounds such as primary metal chelate compounds can be used as absorbers for semiconductor lasers.

Examples of the metal chelate compounds used in the present invention are represented by the following general formulas [11 to [7].

11+s (wherein RI5 may be a hydrogen atom, hydroxyl group, alkyl group, or aryl group and may be bonded to the other RI5,
R16 represents an alkyl group, a halogen atom, a hydrogen atom, a nitro group, or a benzo-fused group, and the central metal M is Gu,
General formula [2] (representing Ni, Co or Pd) (In the formula, R17 may be a hydrogen atom, a hydroxyl group, an alkyl group, or an aryl group, and may be bonded to the other R1?).

1 (, 8 represent a hydrogen atom, a halogen atom, an alkyl group, a nitro group, or a benzo-fused group, and M is Cu.

General formula [3] represents a hydrogen atom, a halogen atom, an alkyl group, or a benzo-fused group, M represents Cu, Ni, or Pd) General formula [5] (in the formula , RI9 represents an alkyl group or an aryl group, R20 represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a nitro group or a benzo-fused group, and M represents Cu, Ni or Pd.) General formula [4] ( In the formula, R23 represents a hydrogen atom, a halogen atom, or an alkyl group, and 1M represents Cu or Ni.) General formula [6
] (In the formula, 824 represents a hydrogen atom or an alkyl group, and 1
M represents Cu, Ni, Go or frontage. ) (wherein, R21 is an alkyl group or an aryl group, and R22 is a general formula [
7] Table 3-1 (wherein, R2'5+ LG is a substituted or unsubstituted alkyl group, acyl group, or aryl group, or R2S+ 82
0M which may form an aromatic ring with 6 is Cu, Ni,
(represents Go or Pd; in this case, M has a charge and may have a counter ion) Next, specific compound examples of the metal chelate compounds represented by the general formulas [1] to [7] are shown below. Listed in Table 3 below,
The present invention is not limited to these.

[1] [11 [1F [1] [11 [11 [1] [1] [1] [11 [2] [2] [2] [2] [2] [2] [2] [2] [2] [2] [2] R+5-Off R+5-Of+ R+s=l+ RIS=C211% R15=I-C31k R15=n-CaH++ R15-n-Cs1l+z R+5-C6H5 1ets resistance I R,5-CH,- R,,-H R,,-CH.

R+t=OH R,7-C,Il.

R,, -(:3H) R+t=CCHt)5CH:s R,,j(CIl□)llCH3 R,,=i-C311t R1720H R,,=OH R,,=-CH2- R,,=H R,,-H R1G=4-C2+15 8, ,=5-Ci) R+a=H R,, = 4-CI (U R,, = 4-CIl.

R1s=ll R,6=5.6-C,l14 R+6=4-NOx R,,=H R,,=H R1a@5-CJs R16-5-C2H5 R,,=4-C1) R,, = 4-CIl.

R,,=5.6-C,H.

R,,=5.6-C,Il.

R+a=4-C:+1I7 R1a resistance 1 R+o=4-NOz Table 3-2 Table 3-3 [2] [3] [3] [3] [3] [3] [3] [3] [3] [3] [4] [4] [4] [4] [4] [4] [4] [4] [4] [5] [5] R,, -C11, - R19"1Jh 8.9= C, l+5 R,,=C611°8.9-4'-(C1-13), N-C,+1°R+s
=4'-Cj'-Cj4- R,,-CHcoR,, =C2+1°8.9=CH3 R+5=CaHs R2,=CH.

Rvr=C*Hs R2-CIl3 R,,=C3H? R2+=(CJs)CH.

R21-(C112)? CI+3 R,, -C, 8% R2,=C11゜ R21=(CII*) 5cll+ R2 co=■ 823! H R+a=4-No2 R,,-H Rzo”4-C)l:+ R2o=4-CtHs R2゜=11 R2゜-4-CH13 R2゜-4-CH3 R20-4-C4) R2゜--N02 R2゜3C,HS R,,-H R*x-4-CH3 Rtz"H Rt2-4-CHs R2g-Calls R22=C6H’S R,, -5,6-C,H.

R2t=H R2! Showa 4-Cj) [5] [6] [6] [6] [7] [7] [7] [7] [7] [7] [7] [7] , [7] [7] [7 ] Ni Ni Ni R23=4-CH, l R24=I+ R,,=H R2n=2-C21+5 Rzs=CJs Rga=Csl1
%R25=C:ails R26=
C6H%Rzs=P-(Ctlls)J-C6114R
t6=CJlsR2s=P-(CH*)J-C6H4R
26=CG+1582S=C)13COR2G=CH3
GO-825-R2,=-CIl=CIl-CH-CH
--R*5-Rza=-CIl-C-C=C1l-・
I ClllCl! -R□-11.6-CH-C-CH-CH-N (CJs
)2 -R2s-R2g=-(:H-C-CH"CH-tomiCH.

-R,5-R,6,-C1l-C-C=C1l-CH2
Cl2゜-I'1g5-F12s CH=CI-1-CIl=C
I+- The above metal chelate compound has absorption in the near-infrared region, is useful as a stable light-absorbing dye, and has good compatibility or dispersibility with polymer liquid crystals.

Furthermore, other compounds that can be used as semiconductor laser light absorbers include the following.

General formula [8] (In the formula, R2? represents a sulfur atom, a substituted or unsubstituted amino group, an oxygen atom, or a thioketone group, and R211 represents a hydrogen atom, an alkyl group, a halogen atom, or an amino group. 1M
represents Zn, Cu or Ni, General formula [9] (In the formula, R29 represents an alkyl group, aryl group or styryl group, and M represents Cu, Ni or Co.) General formula [! 0] (wherein R3o represents a hydrogen atom, a halogen atom, an alkyl group, an acyl group, or an aryl group, and M is Ni or Zr
) General formula [11] (wherein, R1 is an alkyl group or an aryl group, M is Cu
, represents Ni or Co. ) General formula [12] General formula [14 (wherein, R:12+ R3ff represents an alkyl group or aryl group, M represents Ni) General formula [13] (wherein, RyuG+ R:+7 is hydrogen Atom, halogen atom or alkyl group X is oxygen atom or sulfur atom 1M is Ni
) General formula [15] % formula % (wherein R: +41 R3S is an alkyl group, an amino group,
An alicyclic compound may be formed by combining ll:ls with an aryl group, a furan group, or Rff4. M represents Ni. )
(In the formula, 83a, R39 is a hydrogen atom, an alkyl group,
halogen atom or nitro group, X is oxygen atom or sulfur atom 1M is old, Y represents quaternary ammonium cation,
) General formula [16] Next, representative examples of the compounds represented by the above general formulas [8] to [17] are listed in Table 4 below, but the present invention is not limited thereto.

(In the formula, R4゜ is an amino group 1M is Cu, Ni,
General formula [17] (representing Co or Pd) (wherein, R41 is a hydrogen atom, a halogen atom, an alkyl group, an acyl group, a nitro group, or an alkoxyl group, and M is a Zn
, Cu, Ni or CO) table [8] [8] [8] [8] [8] [8] [8] [8] [8] [8] [8] [8] [9 ] [9] [9] [9] [lO] [lO] [lO] R2?・OR2? °0 R11?・5 ntt・S R2? °S R2?S R2? ;S R2,; N11 R2?・N)l R2?・NCII.

R2?・NHR2?・C-5 aSS・C,Ht R29°C611% R29・C, l amount% Cl-Clto R29・(:i'-C,H,CH=CIl-R-10°
H Rzo'H Rko. ;CH3CO R2♂°■ R,,,5-CI(Y11ta・H R2a;5-Cj) R□;5-CII* R2a;4-(:)li Rza;5-((:Ht)J R21S・■ R26・5-C113 R211・ll R26・6-C2H.

R28;I+ xkneeX;C1) ×;- [IO] [IO] [! 1] [11] [11] [11] [12] [12] [12] [13] [13] [13] N1 cI! X;- C3H, x;- CIl5 C3+1°! 1-(CIlff)2N-C6114-p-(CIlff
z) J-CaHn- CIl, R, Yu; (:1lxC,1
I5R:1. ;C21ts C611S R33;C6115Nl1
2R Yu,;Ni1□C,H5Itko5ac6)Is R,,;-(:11.CIl2- R,5;-
CIl□CH2- (R34 and R, 35 combine to form a ring) [lco] [13] [+4] [14] R34;C)l.

R34;C2+! .

X:OR, ;11 x;o R,6;5-CII.

R-+s; CH3 Rzs;C211I R3t;H R+, :@-CH.

table [14] [14] [14] [14] [14] [14] [5] [15] [5] [15] [15 pieces [16] [16] [7] [17] [17] [+7 pieces X-OR3,-4-CH3 X-OR3G-5-CIl X-3R3s'H X-5R,6-5-Cl43 X-3Rzs'4-C11+ X-3R3, 5-CR X·OR3,;:1-CH.

X-OR, ;:1-Cj) X'OR311'4-N02 X-5R, I, ・H X-3R, 8-3-NO□ R, ; (C, Hq)2N R40; (C5III 1) 2N Ro・H R41・4-CI! R41・4-N02 R-+; 5-C1b R371-Cl13 R:+y;I)-Cj' R,,;H R,,1-C11゜ Rlyl-Calls R:l? ;P-C2H5 R39・11 R39・4-CH3 R Yu, 4-CH5 R,,;4-C)13 R: +, l; 4-C2H.

The above metal complexes used in the present invention are manufactured by Barry B.
Gray et al., Journal of the American Chemical Society, Vol. 88, pp. 43-50 and 4870.
~4875 pages, or Journal of the American Chemical by Schranzer and Maibeek et al.
Society Volume 87 1483~! Synthesized according to the method described on page 489.

The above compound has absorption in the near-infrared region, is useful as a stable light-absorbing dye, and has good compatibility or dispersibility with polymeric liquid crystal compounds.

Further, the polymeric liquid crystal compound may contain two or more of the above compounds.

Further, the above compound may be combined with other near-infrared absorbing dyes or dichroic dyes. Typical examples of near-infrared absorbing dyes that can be suitably combined include cyanine, merocyanine, phthalocyanine, tetrahydrocholine, and dioxazine. , anthraquinone, triphenylthiazine, xanthine, triphenylmethane, pyrylium, croconium, azulene and triphenylamine.

Note that the amount of the above compound added to the liquid crystal is 0% by weight.
．． It may be about 1% to 20%, preferably 0.2 to 10%. The polymeric liquid crystal compound used in the present invention is a polymeric thermotropic liquid crystal, and uses a nematic, smectic, chiral smectic, or cholesteric phase as an intermediate phase.

The polymer liquid crystal compound can be used in combination with several different polymer liquid crystal compounds. It can also be used as a mixture of a polymer liquid crystal compound and a low molecular liquid crystal.
In that case, the weight ratio to the polymeric liquid crystal compound 1 is preferably 5 or less.

Polymer liquid crystal compounds may include polymers (for example, olefin resins, acrylic resins), if necessary.

Polystyrene resins, polyester resins, polyurethane resins, polycarbonate resins, etc.), oligomers, various plasticizers, various stabilizers, quenchers, etc. may be contained.

For making the polymer liquid crystal composition into a thin film, for example, the liquid crystal material may be sandwiched between a pair of disk substrates made of glass or plastic and heated and pressure molded, or the liquid crystal material may be heated to an appropriate viscosity. , a method of applying the material onto a disk substrate by spin code, dipping, bar code, roll coating, etc., and a method of applying the material in a thin film state and then polymerizing it to form a polymer liquid crystal.

The thickness of the polymer liquid crystal composition used is 0.05 to
o It is an IL layer, and if it is less than 0.05, sufficient resolution as a hologram cannot be obtained, and if it exceeds 100 μm, it becomes difficult to perform uniform recording and reproduction in the thickness direction.

More preferably, it is used in a range of 0.1 to 80 μm.

Next, FIG. 3 shows an example of an information storage medium used in the present invention, FIG. 3(a) is a cross-sectional view of the information storage medium of the present invention, and FIG. 3(b) is a cross-sectional view taken along the line AA. be.

The information storage medium 7 shown in FIG. 3 has a pair of substrates l and la made of glass plates, plastic plates, etc.
This pair of substrates 1. is held at a predetermined distance. It has a cell structure bonded with an adhesive 6 for sealing the substrate 1, and furthermore, a transparent electrode 2 is formed in a predetermined pattern on the substrate 1. Moreover, an electrode consisting of a transparent electrode 2a facing the above-mentioned transparent electrode 2 is formed at -E of the substrate 1a.

The substrate 1a provided with such a transparent electrode 2a includes, for example,
-Inorganic insulating materials such as silicon oxide, silicon oxide, aluminum oxide, zirconia, magnesium fluoride, cerium oxide, cerium fluoride, silicon nitride, silicon carbide, boron nitride, polyvinyl alcohol, polyimide, polyamideimide, polyesterimide , polyvaraxycillin. The orientation control s5 may be formed by forming a film using an organic insulating material such as polyester, polycarbonate, polyvinyl acetal, polyvinyl chloride, polyamide, polystyrene, cellulose resin, melamine resin, urea resin, or acrylic resin.

This orientation control H5 is obtained by forming a film of an inorganic insulating material or an organic insulating material as described above, and then rubbing the surface in one direction with velvet, cloth, or paper.

In another preferred embodiment of the present invention, SiO or Sin.

The orientation amount aSS can be obtained by forming a film of an inorganic insulating material such as on the substrate 1a by an oblique vapor deposition method.

In another specific example, after forming a film of the above-mentioned inorganic insulating material or organic insulating material on the surface of the substrate 1a made of glass or plastic or on the substrate 1a, the surface of the film is etched by an oblique etching method. Accordingly, an orientation control effect can be imparted to the surface.

The above-mentioned alignment control film 5 preferably functions as an insulating film at the same time, and for this purpose, the thickness of the alignment control film 5 is generally set in the range of 100 to 1 JLm, preferably 500 to 5000. I can do it. This insulating film also has the advantage of being able to prevent the generation of current caused by trace amounts of impurities contained in the recording layer 3, so that even if the operation is repeated, the polymeric liquid crystal compound will not deteriorate.

Furthermore, in the information storage medium of the present invention, the above-mentioned orientation control 119
5 can be provided on the other substrate l. In addition, to ensure single-molecule alignment, stretching methods such as -axial stretching, biaxial stretching, and inflation stretching, and rearrangement by shearing are preferred.If the film does not have film properties and is difficult to stretch by itself, it is sandwiched in a film. By doing so, the desired orientation can be obtained by co-stretching. 3
indicates a recording layer made of a polymeric liquid crystal composition.

It also forms readable marks or groups for addresses on the information storage medium.

Tracking and smooth addressing are particularly desirable.

The polymeric liquid crystal composition of the present invention is used in an oriented state, and the holographic recording method uses heating of the polymeric liquid crystal composition using the intensity of interference generated by a writing laser beam. Specifically, recording is performed by heating the material to a temperature higher than the tomoyoshi phase and rapidly cooling it to fix it in the tomoyoshi phase, or by disrupting the orientation when it returns to the liquid crystal phase. Even if the material is heated below the isokitic phase or above the isokitic phase, if it returns to the liquid crystal phase, recording can be performed by changing the alignment direction of the polymer liquid crystal by applying an electric field, a magnetic field, etc.

The reference beam 120 is generated by driving the mirror XYθ drive device 107 by the multiplex recording mirror XYθ drive control device 106 and changing the position and angle of the mirror 105.
By changing the data content of the recording light 119 at each reference angle, which is focused on the information storage medium 116 at various angles, input data is holographically stored and multiplexed at each angle in the same recording pit. This makes it possible to store extremely large amounts of information.

During reproduction, only the reference light 120 is irradiated, and the diffracted light is read by the photodetector array 117 and converted into a reproduction signal by the PD (photodetector) signal processing device 118. At this time, it is possible to reproduce the multiplex recorded information depending on the irradiation angle of the reference beam 120.

The photodetector 117 is a shutter array 112
Since the input data given by is reproduced as is, the input data can be read at high speed.

Linearly polarized light may be used as the reproduction light, and in that case, it is desirable to adjust the polarization direction so that the S/N of reproduction is maximized.

The photodetector 117 includes a CdS line sensor, an a-3i line sensor, and a CCD (chan).
gecoupled device), MOS(
metal oxide semiconductor
Lor), Sachicon, Vidicon, CPD (chan
geprimi-ng device), etc.

These photodetector arrays are selected depending on the reproduction light wavelength.

A method for erasing stored content is to heat the entire information storage medium and reorient the recorded information portion. 'T fl also involves partially reorienting the recording area by irradiating the recording area with a laser beam of lower power for a longer time than during recording. - When erasing the item h, reorientation may be promoted by an electric field, a magnetic field, or the like.

[Example] Hereinafter, the present invention will be explained in more detail with reference to Examples.

Embodiment 1 FIG. 2 is a partial schematic diagram showing an example of an information storage medium used in the present invention.

A polyamic acid solution (PIQ manufactured by Hitachi Chemical Co., Ltd., non-volatile content concentration: 1.OwL%) was coated on a glass substrate l provided with an ITO transparent electrode 2 using a spinner coating machine.
A polyimide layer was provided by heat treatment at 20° C. for 30 minutes, 200° C. for 60 minutes, and 350° C. for 30 minutes, and uniaxial orientation was imparted by this rubbing method to form the orientation control 1 film 5.

Next, 1 wt % of an IR absorbing dye represented by the following structural formula (U) was added to the polymeric liquid crystal compound represented by the following structural formula (I), and the solution was dissolved in cyclohexane and coated on the above substrate using a spinner. did.

The film thickness after drying was 5 μ-.

n≧10 (I) (II) Next, on the substrate coated with the above-mentioned polymeric liquid crystal composition, another substrate, on which the polyimide alignment control film was formed by the same treatment, was attached with the alignment direction aligned. Combined. Thereafter, it was heated to 120°C and slowly cooled to obtain a uniaxially oriented information storage medium.

Using the apparatus shown in Fig. 1, bit information was recorded on this information storage medium using a semiconductor laser with a wavelength of 8]On and an output of 1OsW, and when only the reference light was reproduced at 1mW, an S of 15dB was obtained. /N bit information was reproduced.

It was possible to erase the data by heating this storage medium to 120°C and slowly cooling it, and the S/N did not change even if recording was performed again.

[Effects of the Invention] As explained above, according to the information storage device of the present invention,
By recording and reproducing multiple bits of information on a photoreceptor layer made of a polymeric liquid crystal composition by holographic means, it is possible to record a large amount of data at high speed with good sensitivity.
It has an effect that can be regenerated.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of an information storage device of the present invention, FIG.
The figure is a partial schematic diagram showing an example of the information storage medium used in the present invention, FIG. 3 is a partial schematic diagram showing another example of the information storage medium used in the present invention, and FIG. , FIG. 3(b) is a cross-sectional view taken along line AA. 1, la, 115...substrate 2, 2a...
Transparent electrode 3... Recording layer 4... Spacer 5.5a... Orientation control film 6... Adhesive 7.11
6... Information storage medium 101... Laser light source driving device 102... Laser light source 103... Collimator lens 104... Half mirror 105, 113... Mirror 106... Mirror for multiplex recording xYO Drive control device 10
7...Mirror X'l drive device 108, 109...Condensing lens 110...Input data transfer device 1+8...Shutter array drive circuit...Shutter array...Polymer liquid crystal composition photoreceptor Layer...Photodetector...PD (Photodetector) signal processing device...
Recording light...Reference light

Claims (1)

[Scope of Claims] (1) Means for irradiating laser light, means for separating the laser light into reference light and recording light, and means for imparting a plurality of bits of information consisting of intensity modulation to the separated recording light. , comprising a means for recording interference between a reference beam made of a polymer liquid crystal composition and a recording beam, and a means consisting of a plurality of photodetectors for receiving diffracted light generated when the reference beam is irradiated. information storage device. (2) The information storage device according to claim 1, wherein the laser light is a laser light provided by a semiconductor laser. (3) The information storage device according to claim 1, wherein the polymer liquid crystal composition is subjected to alignment treatment in the means for recording the interference between the reference light and the recording light made of the polymer liquid crystal composition. (4) The information storage device according to claim 1, wherein the polymer liquid crystal composition absorbs laser light. (5) The information storage device according to claim 1, wherein the resolution of the plurality of photodetectors that receive the diffracted light is equal to or greater than the amount of the plurality of bits of information formed by intensity modulation applied to the recording light.