JPH0152686B2 - - Google Patents
Info
- Publication number
- JPH0152686B2 JPH0152686B2 JP56062604A JP6260481A JPH0152686B2 JP H0152686 B2 JPH0152686 B2 JP H0152686B2 JP 56062604 A JP56062604 A JP 56062604A JP 6260481 A JP6260481 A JP 6260481A JP H0152686 B2 JPH0152686 B2 JP H0152686B2
- Authority
- JP
- Japan
- Prior art keywords
- liquid crystal
- crystal element
- voltage signal
- measuring
- measurement
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- 239000004973 liquid crystal related substance Substances 0.000 claims description 98
- 238000005259 measurement Methods 0.000 claims description 28
- 239000003990 capacitor Substances 0.000 claims description 23
- 230000002123 temporal effect Effects 0.000 claims description 17
- 238000000034 method Methods 0.000 claims description 11
- 239000002131 composite material Substances 0.000 claims description 6
- 230000003287 optical effect Effects 0.000 description 7
- 238000010586 diagram Methods 0.000 description 6
- 230000010355 oscillation Effects 0.000 description 5
- 239000000463 material Substances 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/1306—Details
- G02F1/1309—Repairing; Testing
Landscapes
- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Testing Electric Properties And Detecting Electric Faults (AREA)
- Testing Of Optical Devices Or Fibers (AREA)
- Liquid Crystal (AREA)
- Liquid Crystal Display Device Control (AREA)
Description
【発明の詳細な説明】
本発明は、液晶素子の応答速度測定方法に係
り、特に液晶素子中の液晶分子の配列変化を電気
容量の時間的変化としてとらえる測定方法に関す
る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring the response speed of a liquid crystal element, and more particularly to a measuring method that captures changes in the arrangement of liquid crystal molecules in a liquid crystal element as temporal changes in capacitance.
従来では、液晶素子の応答速度測定は第１図に
示すように行なわれていた。 Conventionally, the response speed of a liquid crystal element has been measured as shown in FIG.
すなわち、第１図に於いて、光源１から放射さ
れる光を液晶素子２を通して、光検出器３で測定
する光学系と、液晶素子駆動回路４および光信号
処理回路５からなる測定測置を用い、たとえば、
オシユロスコープ６により、第２図に示すような
波形を観測していた。 That is, in FIG. 1, there is shown a measurement setup consisting of an optical system that measures light emitted from a light source 1 through a liquid crystal element 2 and a photodetector 3, a liquid crystal element drive circuit 4, and an optical signal processing circuit 5. For example,
Using the oscilloscope 6, a waveform as shown in FIG. 2 was observed.
第１図の装置において、液晶素子２は液晶素子
駆動回路４により、第２図ａのように、時刻t0か
らt1まで駆動信号が印加される。 In the device shown in FIG. 1, a driving signal is applied to the liquid crystal element 2 by a liquid crystal element driving circuit 4 from time t 0 to t 1 as shown in FIG. 2 a.
このとき、液晶素子２の透過率が変化するので
光検出器３に入射する光量が変化し、光信号処理
回路５の出力は第２図ｂのように変化する。 At this time, since the transmittance of the liquid crystal element 2 changes, the amount of light incident on the photodetector 3 changes, and the output of the optical signal processing circuit 5 changes as shown in FIG. 2b.
同図から、液晶素子の応答時間を読取るが、た
とえば変化幅の90％まで変化する時間tpo，tOffと
定義すれば、図中に示したようにtpo，tOffを定め
ることができる。 From the figure, we can read the response time of the liquid crystal element. For example, if we define the time t po and t Off to change up to 90% of the variation width, we can determine t po and t Off as shown in the figure. .
ところが、この測定方法は液晶素子の光学的性
質の変化速度を正しく測定することは可能である
が、例えば、第２図ｃに示す様に、電圧印加時
（ｔ＝t0）より、少し遅れて、透過光強度が変化
し始めている。液晶素子の旋光性やねじれのため
に、光学的性質の変化と液晶素子中の液晶分子の
配列変化は必ずしも一致しないことがよく知られ
ている。したがつて、液晶分子自体の応答速度を
測定するためには上記した方法による測定では不
充分であつた。 However, although this measurement method can accurately measure the rate of change in the optical properties of a liquid crystal element, for example, as shown in Figure 2c, there is a slight delay from when voltage is applied (t = t 0 ). As a result, the transmitted light intensity begins to change. It is well known that changes in optical properties and changes in the arrangement of liquid crystal molecules in a liquid crystal element do not necessarily coincide due to the optical rotation and twist of the liquid crystal element. Therefore, the above method is insufficient for measuring the response speed of the liquid crystal molecules themselves.
本発明の目的は、上述した欠点を除去し、液晶
分子自体の応答速度を測定するに好適な液晶素子
の応答速度測定方法を提供することにある。 An object of the present invention is to eliminate the above-mentioned drawbacks and provide a method for measuring the response speed of a liquid crystal element suitable for measuring the response speed of the liquid crystal molecules themselves.
上記目的を達成する本発明の特徴とするところ
は、液晶素子の電気容量の時間的変化を測定する
ことによつて液晶素子中の液晶分子の配列の時間
的変化即ち応答速度を検出するものである。 The present invention is characterized in that the temporal change in the arrangement of liquid crystal molecules in the liquid crystal element, that is, the response speed, is detected by measuring the temporal change in the capacitance of the liquid crystal element. be.
本発明を具体的に述べると、液晶素子とインピ
ーダンスを直列に接続し、交流電圧信号を印加
し、インピーダンスに印加された交流電圧信号の
時間的変化を測定することによつて、液晶素子中
の液晶分子の配列の時間的変化を検出するもので
ある。 Specifically describing the present invention, a liquid crystal element and an impedance are connected in series, an AC voltage signal is applied, and a temporal change in the AC voltage signal applied to the impedance is measured. This detects temporal changes in the arrangement of liquid crystal molecules.
さらに、具体的に述べれば、液晶素子とインピ
ーダンスを直列に接続し、駆動用交流電圧信号と
該信号とは異種（例えば、周波数が違う）測定用
交流電圧信号を重畳した信号を印加し、インピー
ダンスに印加された測定用交流電圧信号成分を測
定することによつて、液晶素子中の液晶分子の時
間的変化を検出するものである。 More specifically, a liquid crystal element and an impedance are connected in series, and a signal obtained by superimposing a driving AC voltage signal and a measuring AC voltage signal of a different type (for example, a different frequency) from the driving AC voltage signal is applied, and the impedance is By measuring the measurement AC voltage signal component applied to the liquid crystal element, temporal changes in liquid crystal molecules in the liquid crystal element are detected.
また、測定用交流電圧信号の実効電圧は液晶素
子の駆動状態に影響を与えない程度であり、ま
た、インピーダンスはコンデンサであることが好
ましい。 Further, it is preferable that the effective voltage of the AC voltage signal for measurement is such that it does not affect the driving state of the liquid crystal element, and that the impedance is a capacitor.
ここで、液晶素子中の液晶分子の配列の状態と
液晶素子の電気容量について説明する。 Here, the alignment state of liquid crystal molecules in a liquid crystal element and the capacitance of the liquid crystal element will be explained.
表示素子などに実用されている液晶分子は、通
常誘電率異方性を有しており、この誘電率異方性
のゆえに、電圧印加によりその配列を変化する。
従つて、光学的性質も変化し表示素子としての機
能をはたしている。 Liquid crystal molecules used in display devices and the like usually have dielectric anisotropy, and because of this dielectric anisotropy, their arrangement changes when voltage is applied.
Therefore, its optical properties also change and it functions as a display element.
誘電率異方性とは、液晶分子の長軸方向の誘電
率εと短軸方向の誘電率ε⊥が異なつている
（ε≠ε⊥）ことであり、これゆえ液晶分子の配
列方向が変化すると、液晶素子の電気容量が変化
する。 Dielectric anisotropy refers to the fact that the dielectric constant ε in the long axis direction of liquid crystal molecules and the dielectric constant ε⊥ in the short axis direction are different (ε≠ε⊥), and therefore the alignment direction of liquid crystal molecules changes. Then, the capacitance of the liquid crystal element changes.
なお、一般に普及しているTN（Twisted
Neinatic）型液晶素子ではOFF状態からON状態
に変化するとき、電気容量が２〜４倍に増加する
が、使用される液晶素子の種類によつてこの値は
異なる。 In addition, the generally popular TN (Twisted
In a Neinatic type liquid crystal element, when changing from an OFF state to an ON state, the capacitance increases two to four times, but this value differs depending on the type of liquid crystal element used.
本発明を実施するのに好適な回路構成を第３図
に示す。 A circuit configuration suitable for carrying out the present invention is shown in FIG.
同図に於いて、１０は駆動用交流電圧信号VA
を発生する発振回路、１１は測定用交流電圧信号
VBを発生する発振回路、１２は駆動用交流電圧
信号VAのスイツチング回路、１３は測定用交流
電圧信号VBとスイツチング回路１２の出力であ
る駆動用交流電圧信号VCを加算する加算回路、
１４は電極が設けられた少なくとも２枚の基板間
に液晶材料を封入した液晶素子、１５は液晶素子
１４と直列に接続されたインピーダンスとしての
コンデンサ、１６はコンデンサ１５に印加される
信号VEの測定用交流電圧信号成分を検出する弁
別回路で、具体的には駆動用交流電圧信号VAと
測定用交流電圧信号VBの周波数の中間にしや断
周波数を有するハイパスフイルタである。弁別回
路はこれに限らず、駆動用交流電圧信号VAのみ
を除去するバンドエリミネーシヨンフイルタ等で
も良い。 In the same figure, 10 is a driving AC voltage signal V A
11 is an oscillation circuit that generates an AC voltage signal for measurement.
12 is a switching circuit for driving AC voltage signal V A ; 13 is an addition circuit for adding measurement AC voltage signal V B and driving AC voltage signal V C , which is the output of switching circuit 12 . ,
14 is a liquid crystal element in which a liquid crystal material is sealed between at least two substrates provided with electrodes; 15 is a capacitor connected in series with the liquid crystal element 14 as an impedance; 16 is a signal V E applied to the capacitor 15; This is a discrimination circuit that detects the AC voltage signal component for measurement, and specifically, it is a high-pass filter having a shearing frequency midway between the frequencies of the AC voltage signal V A for driving and the AC voltage signal V B for measurement. The discrimination circuit is not limited to this, and may be a band elimination filter or the like that removes only the drive AC voltage signal VA .
ここで、液晶素子１４は本質的にコンデンサと
して働くので、インピーダンス１５に加わる信号
に位相差が生じない様にインピーダンス１５はコ
ンデンサであることが望ましい。 Here, since the liquid crystal element 14 essentially functions as a capacitor, it is desirable that the impedance 15 is a capacitor so that no phase difference occurs in the signal applied to the impedance 15.
第３図の回路に於ける信号波形を第４図に示
し、これらを用いて、液晶素子１４をOFF状態
からON状態へ変化させたときの本発明の実施例
を詳細に説明する。 The signal waveforms in the circuit of FIG. 3 are shown in FIG. 4, and using these signals, an embodiment of the present invention will be described in detail when the liquid crystal element 14 is changed from the OFF state to the ON state.
発振回路１０より発生される駆動用交流電圧信
号VAは第４図ａに示す如く周波数200Hzの正弦波
であり、スイツチング回路１２により、第４図ｂ
に示す如く、駆動用交流電圧信号VCは、OFF状
態からON状態へ変化する。発振回路１１より発
生される測定用交流電圧信号VBは第４図ｃに示
す如く周波数４ＫHzの正弦波である。 The driving AC voltage signal V A generated by the oscillation circuit 10 is a sine wave with a frequency of 200 Hz as shown in FIG.
As shown in the figure, the driving AC voltage signal V C changes from the OFF state to the ON state. The measurement AC voltage signal V B generated by the oscillation circuit 11 is a sine wave with a frequency of 4 KHz as shown in FIG. 4c.
ここで、測定用交流電圧信号VBは、液晶素子
の駆動状態に影響しない様に電圧値を小さくする
ことが必要であるが、通常0.1V以下であること
が望ましい。 Here, the measurement AC voltage signal V B needs to have a small voltage value so as not to affect the driving state of the liquid crystal element, but it is usually desirable to have a voltage value of 0.1 V or less.
加算回路１３によつて、駆動用交流電圧信号
VCと測定用交流電圧信号VBは加算され、第４図
ｄに示す合成電圧信号VDが液晶素子１４とコン
デンサ１５に印加される。 The adder circuit 13 generates a driving AC voltage signal.
V C and the measurement AC voltage signal V B are added, and a composite voltage signal V D shown in FIG. 4d is applied to the liquid crystal element 14 and the capacitor 15.
時刻t0に於いて、駆動用交流電圧信号が印加さ
れると、液晶素子中の液晶分子の配列方向が変化
し、前述の如く液晶素子１４の電気容量は変化す
る。例えば、TN型液晶素子の様に、ε−ε⊥＞
０の液晶材料を用いた場合は、液晶素子１４の電
気容量は増加する。 At time t 0 , when the driving AC voltage signal is applied, the alignment direction of the liquid crystal molecules in the liquid crystal element changes, and the capacitance of the liquid crystal element 14 changes as described above. For example, like a TN type liquid crystal element, ε−ε⊥＞
When a liquid crystal material of 0 is used, the capacitance of the liquid crystal element 14 increases.
液晶素子１４の電気容量をＣ（ｔ）、コンデンサ
１５の電気容量C0（一定）とすると、コンデンサ
１５に印加される電圧信号VEは式(1)の如く表わ
せる。 Assuming that the capacitance of the liquid crystal element 14 is C(t) and the capacitance C 0 (constant) of the capacitor 15, the voltage signal V E applied to the capacitor 15 can be expressed as shown in equation (1).
VE＝Ｃ（ｔ）／C0＋Ｃ（ｔ）VD ……(1)
式(1)より、液晶素子１４の電気容量Ｃ（ｔ）が
大きくなるとコンデンサ１５に加わる電圧信号
VEも大きくなることがわかる。さらに、コンデ
ンサ１５の電気容量C0を液晶素子１４の電気容
量Ｃ（ｔ）に比して十分大きくすれば、式(1)は
VE＝Ｃ（ｔ）／C0VD（C0≫Ｃ（ｔ）） ……(2)
となり、コンデンサ１５に印加される電圧信号
VEと液晶素子１４の電気容量Ｃ（ｔ）は略比例す
る。 V E = C (t) / C 0 + C (t) V D ... (1) From equation (1), when the capacitance C (t) of the liquid crystal element 14 increases, the voltage signal applied to the capacitor 15 increases.
It can be seen that V E also increases. Furthermore, if the capacitance C 0 of the capacitor 15 is made sufficiently larger than the capacitance C(t) of the liquid crystal element 14, equation (1) becomes V E =C(t)/C 0 V D (C 0 ≫ C(t)) ...(2), and the voltage signal applied to the capacitor 15
V E and the electric capacitance C(t) of the liquid crystal element 14 are approximately proportional.
従つて、コンデンサ１５に印加される電圧信号
VEの時間的変化を測定することは、液晶素子１
４の電気容量の時間的変化を測定することにな
り、すなわち、液晶素子１４中の液晶分子の時間
的変化を検出することになる。 Therefore, the voltage signal applied to capacitor 15
Measuring the temporal change in V E is done using the liquid crystal element 1.
In other words, the temporal change in the liquid crystal molecules in the liquid crystal element 14 is detected.
第４図ｅに示す様なコンデンサ１５に印加され
る電圧信号VEはハイパスフイルタによつて、駆
動用交流電圧信号成分が除去され、第４図ｆに示
す様な測定用交流電圧信号成分VFが出力される。
この波形の包絡線VGは第４図ｇの様になり、VG
が液晶素子１４の電気容量の変化、すなわち液晶
素子１４の時間的変化を直接表わすことになる。 The driving AC voltage signal component is removed from the voltage signal V E applied to the capacitor 15 as shown in FIG. 4e by a high-pass filter, and the measurement AC voltage signal component V as shown in FIG. F is output.
The envelope V G of this waveform is as shown in Figure 4g, and V G
directly represents the change in the capacitance of the liquid crystal element 14, that is, the change in the liquid crystal element 14 over time.
ｔ＝t0で駆動用交流電圧信号をON状態にした
時のTN型液晶素子の透過光強度の時間的変化を
第５図ａに、電気容量の時間的変化を第５図ｂに
示す。これらの図より明らかな様に、透過光強度
に比べて電気容量は早く変化し始めている。 Figure 5a shows the temporal change in the transmitted light intensity of the TN liquid crystal element when the driving AC voltage signal is turned on at t= t0 , and Figure 5b shows the temporal change in the capacitance. As is clear from these figures, the capacitance begins to change faster than the transmitted light intensity.
従つて、本発明の実施例によれば液晶素子中の
液晶分子自体の応答速度を正確に測定することが
できる。 Therefore, according to the embodiment of the present invention, it is possible to accurately measure the response speed of the liquid crystal molecules themselves in the liquid crystal element.
尚、測定用交流電圧信号は液晶素子のOFF状
態とON状態の両方に含まれているが、駆動用交
流電圧信号をOFFからONに切換えると同時に、
測定用交流電圧信号Ｏ（Ｖ）から任意の電圧値に
変化させても良い。 Note that the measurement AC voltage signal is included in both the OFF and ON states of the liquid crystal element, but at the same time when the driving AC voltage signal is switched from OFF to ON,
The measurement AC voltage signal O (V) may be changed to an arbitrary voltage value.
さらに、液晶素子１４とコンデンサ１５に印加
される交流電圧信号は２種類ではなく、駆動用交
流電圧信号だけでも、本発明は適用できる。この
場合、第３図に於ける発振回路１１、加算回路１
３、ハイパスフイルタ１６は省略でき、回路を簡
素化することができる。 Furthermore, the present invention can be applied to not only two types of AC voltage signals applied to the liquid crystal element 14 and the capacitor 15 but only a driving AC voltage signal. In this case, the oscillation circuit 11 and adder circuit 1 in FIG.
3. The high-pass filter 16 can be omitted, and the circuit can be simplified.
次に液晶素子１４をON状態からOFF状態へ変
化させたときの本発明の実施例を詳細に説明す
る。 Next, an embodiment of the present invention will be described in detail when the liquid crystal element 14 is changed from an ON state to an OFF state.
第６図は第３図に示す回路に於ける、液晶素子
１４をON状態からOFF状態に変化させるときの
信号波形である。 FIG. 6 shows a signal waveform when changing the liquid crystal element 14 from an ON state to an OFF state in the circuit shown in FIG.
第６図では、駆動用交流電圧信号VCが第６図
ｂに示す如くｔ＝t0の時刻でONからOFFへ切換
わるので、合成電圧信号VD、コンデンサ１５に
印加される電圧信号VE，VEの測定用交流電圧信
号VF，VFの包絡線VGはそれぞれ第６図ｄ〜ｇの
様に変化する。第６図ａ，ｃに示す発振回路１０
及び１１より発生される駆動用交流電圧信号VA
及び測定用交流電圧信号VBは第４図ａ，ｃと同
一の波形である。 In FIG. 6, since the driving AC voltage signal V C switches from ON to OFF at time t=t 0 as shown in FIG. 6 b, the composite voltage signal V D and the voltage signal V applied to the capacitor 15 The envelopes V G of the AC voltage signals V F and V F for measurement of E and V E change as shown in FIGS. 6d to 6g, respectively. Oscillation circuit 10 shown in FIGS. 6a and 6c
and the driving AC voltage signal V A generated from 11.
The measurement AC voltage signal V B has the same waveform as in FIGS. 4a and 4c.
この場合も液晶素子１４をOFF状態からON状
態へ変化させる場合と同様に液晶素子中の液晶分
子自体の応答速度を正確に測定することができ
る。 In this case as well, the response speed of the liquid crystal molecules themselves in the liquid crystal element can be accurately measured, as in the case of changing the liquid crystal element 14 from the OFF state to the ON state.
さらに本実施例の場合、駆動用交流電圧信号
VCがOFFに切換つても、測定用交流電圧信号VB
は常に流れているので、コンデンサ１５に印加さ
れる電圧信号VEの測定用交流電圧信号成分VFに
よつて液晶分子の時間的変化を検出することがで
きる。 Furthermore, in the case of this embodiment, the driving AC voltage signal
Even if V C is switched OFF, the measurement AC voltage signal V B
is constantly flowing, so the measurement alternating current voltage signal component V F of the voltage signal V E applied to the capacitor 15 allows the temporal change in the liquid crystal molecules to be detected.
尚、第４図、第６図に示した駆動用交流電圧信
号VAと測定用交流電圧信号VBは、合成された信
号が弁別回路によつて弁別できるものであれば良
い。従つて、周波数はどちらが高くても良く、周
波数が同じでも、位相がずれていれば良い。さら
に、正弦波に限らず三角形、矩形波等の一般の交
流信号にも本発明は適用できる。 Note that the driving AC voltage signal V A and the measurement AC voltage signal V B shown in FIGS. 4 and 6 may be any signal as long as the combined signal can be discriminated by the discrimination circuit. Therefore, it does not matter which frequency is higher, and even if the frequencies are the same, it is sufficient that the phases are shifted. Furthermore, the present invention is applicable not only to sine waves but also to general AC signals such as triangular and rectangular waves.
また、駆動用交流電圧信号VAはOVから任意の
電圧値に変化させた場合を例にとつたが、これに
限定されず任意の電圧値から任意の電圧値に変化
させても良い。 Further, although the driving AC voltage signal V A has been exemplified as being changed from OV to an arbitrary voltage value, the present invention is not limited to this, and may be changed from an arbitrary voltage value to an arbitrary voltage value.
第３図に示される加算回路１３は種々の回路で
実現できるが、一例として第７図に示す様な演算
増幅器を用いたものを例示する。第７図に於い
て、演算増幅器１７の反入力端子１８に抵抗１
９，２０を介して駆動用交流電圧信号VC及び測
定用交流電圧信号VBを入力すると、出力端子２
１には加算された合成電圧信号VDが出力される。 The adder circuit 13 shown in FIG. 3 can be realized by various circuits, but as an example, one using an operational amplifier as shown in FIG. 7 will be exemplified. In FIG. 7, a resistor 1 is connected to the inverse input terminal 18 of the operational amplifier 17.
When the driving AC voltage signal V C and the measurement AC voltage signal V B are input through terminals 9 and 20, the output terminal 2
1, the added composite voltage signal V D is output.
また、式(1)、式(2)より、コンデンサ１５の電気
容量C0を液晶素子の電気容量Ｃ（ｔ）より大きく
するにしたがつて、コンデンサ１５に印加される
電圧信号VEの変化は液晶素子１４の電気容量の
変化を正確に現わす様になり液晶分子の配列の時
間的変化を検出する精度が上がる。しかし、コン
デンサ１５の電気容量C0を大きくすると、式(2)
よりコンデンサ１５に印加される電圧信号VEは
小さくなるので、弁別回路であるハイパスフイル
タ１６の前段に信号増幅回路を挿入する場合があ
る。 Also, from equations (1) and (2), as the capacitance C 0 of the capacitor 15 is made larger than the capacitance C(t) of the liquid crystal element, the voltage signal V E applied to the capacitor 15 changes. will accurately represent changes in the capacitance of the liquid crystal element 14, and the accuracy in detecting temporal changes in the arrangement of liquid crystal molecules will increase. However, if the capacitance C 0 of the capacitor 15 is increased, equation (2)
Since the voltage signal V E applied to the capacitor 15 becomes smaller, a signal amplification circuit may be inserted before the high-pass filter 16, which is a discrimination circuit.
さらには、弁別回路であるハイパスフイルタ１
６の後段に、測定用交流電圧信号VFの包絡線VG
を取るための回路や、波形記録のための波形記録
装置等を設けると測定に好都合である。 Furthermore, a high-pass filter 1, which is a discrimination circuit,
6, the envelope V G of the measurement AC voltage signal V F
It is convenient for measurements to be provided with a circuit for taking the waveform and a waveform recording device for recording the waveform.
なお、液晶素子とコンデンサの分圧比を測定す
るという測定原理上、液晶素子の応答時間内で液
晶素子に印加される電圧も変化させなければなら
ない。 Note that due to the measurement principle of measuring the voltage division ratio between the liquid crystal element and the capacitor, the voltage applied to the liquid crystal element must also be changed within the response time of the liquid crystal element.
以上述べた様に本発明によれば、液晶素子中の
液晶分子自体の配列変化を測定できるもので、液
晶分子自体の応答速度を測定するに好適な液晶素
子の応答速度測定方法を得ることができる。 As described above, according to the present invention, it is possible to measure changes in the arrangement of liquid crystal molecules themselves in a liquid crystal element, and it is possible to obtain a method for measuring the response speed of a liquid crystal element suitable for measuring the response speed of the liquid crystal molecules themselves. can.
第１図は従来の液晶素子の応答速度測定方法を
示すブロツク図、第２図は第１図で観測される波
形図、第３図は本発明を実施するのに好適な回路
を示すブロツク図、第４図及び第６図は第３図の
回路に於ける信号波形を示す図、第５図は従来例
による測定結果と本発明の実施例による測定結果
を示す波形図、第７図は本発明の実施例に使用す
る加算回路の一例を示す回路図である。
１４…液晶素子、１５…コンデンサ、１６…ハ
イパスフイルタ。
Fig. 1 is a block diagram showing a conventional method for measuring the response speed of a liquid crystal element, Fig. 2 is a waveform diagram observed in Fig. 1, and Fig. 3 is a block diagram showing a circuit suitable for implementing the present invention. , FIG. 4 and FIG. 6 are diagrams showing signal waveforms in the circuit of FIG. 3, FIG. 5 is a waveform diagram showing measurement results according to the conventional example and measurement results according to the embodiment of the present invention, and FIG. FIG. 2 is a circuit diagram showing an example of an adder circuit used in an embodiment of the present invention. 14...Liquid crystal element, 15...Capacitor, 16...High pass filter.
Claims (1)
ことによつて液晶素子中の液晶分子の配列の時間
的変化を検出することを特徴とする液晶素子の応
答速度測定方法。 ２ 特許請求の範囲第１項において、液晶素子と
インピーダンスを直列に接続し、該液晶素子とイ
ンピーダンス間に交流電圧信号を印加し、インピ
ーダンスに印加される交流電圧信号の時間的変化
を測定することによつて液晶素子中の液晶分子の
配列の時間的変化を検出することを特徴とする液
晶素子の応答速度測定方法。 ３ 特許請求の範囲第２項において、液晶素子と
インピーダンス間に、駆動用交流電圧信号と該信
号とは異種の測定用交流電圧信号が重畳された合
成電圧信号を印加し、インピーダンスに印加され
る合成電圧信号の測定用交流電圧信号成分を測定
することによつて、液晶素子中の液晶分子の配列
の時間的変化を検出することを特徴とする液晶素
子の応答速度測定方法。 ４ 特許請求の範囲第３項において、駆動用交流
電圧信号の周波数と測定用交流電圧信号の周波数
とが違うことを特徴とする液晶素子の応答速度測
定方法。 ５ 特許請求の範囲第３項において、測定用交流
電圧信号の実効電圧は、液晶素子の駆動状態に影
響を与えない程度であることを特徴とする液晶素
子の応答速度測定方法。 ６ 特許請求の範囲第２項及び第３項において、
インピーダンスはコンデンサであることを特徴と
する液晶素子の応答速度測定方法。[Scope of Claims] 1. A method for measuring the response speed of a liquid crystal element, which comprises detecting a temporal change in the arrangement of liquid crystal molecules in a liquid crystal element by measuring a temporal change in capacitance of the liquid crystal element. . 2. In claim 1, a liquid crystal element and an impedance are connected in series, an AC voltage signal is applied between the liquid crystal element and the impedance, and a temporal change in the AC voltage signal applied to the impedance is measured. 1. A method for measuring response speed of a liquid crystal element, comprising detecting temporal changes in arrangement of liquid crystal molecules in the liquid crystal element. 3 In claim 2, a composite voltage signal in which a driving AC voltage signal and a measurement AC voltage signal different from the above signal are superimposed is applied between the liquid crystal element and the impedance, and the composite voltage signal is applied to the impedance. 1. A method for measuring the response speed of a liquid crystal element, comprising detecting a temporal change in the arrangement of liquid crystal molecules in the liquid crystal element by measuring a measurement AC voltage signal component of a composite voltage signal. 4. The method for measuring response speed of a liquid crystal element according to claim 3, characterized in that the frequency of the driving AC voltage signal and the frequency of the measurement AC voltage signal are different. 5. The method for measuring response speed of a liquid crystal element according to claim 3, wherein the effective voltage of the AC voltage signal for measurement is of a level that does not affect the driving state of the liquid crystal element. 6 In claims 2 and 3,
A method for measuring the response speed of a liquid crystal element, characterized in that the impedance is a capacitor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56062604A JPS57178125A (en) | 1981-04-27 | 1981-04-27 | Response speed measuring method of liquid crystal element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56062604A JPS57178125A (en) | 1981-04-27 | 1981-04-27 | Response speed measuring method of liquid crystal element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57178125A JPS57178125A (en) | 1982-11-02 |
| JPH0152686B2 true JPH0152686B2 (en) | 1989-11-09 |
Family
ID=13205087
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56062604A Granted JPS57178125A (en) | 1981-04-27 | 1981-04-27 | Response speed measuring method of liquid crystal element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57178125A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5211599B2 (en) * | 2007-09-14 | 2013-06-12 | 宇部興産株式会社 | Liquid crystal property evaluation system |
-
1981
- 1981-04-27 JP JP56062604A patent/JPS57178125A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57178125A (en) | 1982-11-02 |
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