JPS62247336A - Liquid crystal shutter unit - Google Patents

Abstract

PURPOSE:To simplify and miniaturize constitution for mounting a liquid crystal shutter by providing a driving circuit that supplies driving signals that drive a shutter to an electrode in the substrate of a liquid crystal shutter. CONSTITUTION:The unit is provided with a liquid crystal shutter 1 consisting of a pair of substrates 11, 12 arranged opposite to each other with liquid crystal between and electrodes C, S that form a shutter part A with liquid crystal formed on the inner faces of the pair of substrates 11, 12, and a driving circuit 34 provided on at least one of the pair of substrates 11, 12 of the liquid crystal shutter 1 and supplies driving signals that drive the shutter part A to electrodes C, S. As the driving circuit 34 is installed directly on the substrate of the liquid crystal shutter 1, number of parts of the driving circuit provided independently of the liquid crystal shutter 1 decreases and number of conductors that connect parts of the driving circuit and substrate also decreases. Thus, mounting structure is simplified when mounting a liquid crystal unit and, at the same time, the space for mounting becomes small.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a liquid crystal shutter device equipped with a drive circuit.

[Technical background of the invention and its problems] A liquid crystal shutter has a transparent signal electrode and a common electrode formed on the inner surfaces of a pair of transparent substrates that are placed opposite each other with a liquid crystal interposed therebetween.
A plurality of shutter parts are arranged and configured using these electrodes and liquid crystal to control the original transmission.A drive circuit supplies a drive signal between the two electrodes, drives the liquid crystal, and opens the shutter part. Nen is something that "closes" and controls the original transmission.

This liquid crystal shutter is used, for example, in the original writing head of an original writing type printer. The original write-on printer is
In the original writing head, the light source from the light source is controlled by a liquid crystal shutter and irradiated onto the pre-charged surface of the photosensitive drum, and the electric charge on the light irradiated portion of the drum surface is erased to perform original writing and create an electrostatic latent image. It forms the

Therefore, the liquid crystal shutter used in this manner requires a drive circuit that controls the opening and closing of the shutter section by supplying a signal and a driver drive signal to the common electrode in accordance with print data. However, conventionally, a configuration has been adopted in which the entire drive circuit is provided independently of the liquid crystal shutter and is connected to the liquid crystal shutter via a connecting conductor.

6 shows a conventional configuration of an optical writing head.

In the figure, 1 is a liquid crystal shutter, 2.2 is a printed circuit board, and these printed circuit boards 2, 2 have an integrated circuit (
IC) 3.3 is attached, and the terminal portion of the printed circuit board 2.2 and the terminal portion of the signal electrode substrate of the liquid crystal shutter 1 are connected by flexible sheets 4, 4 on which lead portions are printed. Note that 5 is a light source, 6 is a lens, and 7 is a head cover.

However, with such a conventional configuration, the liquid crystal shutter 1 and the printed circuit board 2.2 are independently mounted inside the head cover 1, and both are further mounted on a flexible sheet 4.2.
4, the mounting of the optical writing head becomes complicated and there is a limit to the miniaturization of the head. In addition, the flexible sheet used for connection has a high connection resistance, the waveform of the drive signal becomes dull, the response characteristics are poor, the strength is weak and wire breakage is easy to occur, and the flexible sheet is susceptible to microscopic damage due to expansion and contraction due to heat. There are various drawbacks such as the inability to achieve precision in pitch alignment with the terminals, and there is a problem in that reliability cannot be achieved in the connection between the liquid crystal shutter and the printed circuit board, that is, the drive circuit.

[Objective of the Invention] The present invention has been made based on the above circumstances, and it is possible to simplify the mounting structure of the liquid crystal shutter and to make the connection between the liquid crystal shutter and the driving circuit reliable by directly providing the driving circuit on the substrate of the liquid crystal shutter. The purpose of this invention is to provide a liquid crystal device with improved performance.

[Summary of the Invention] The liquid crystal shutter device of the present invention comprises a pair of substrates facing each other with a liquid crystal interposed therebetween, and electrodes formed on the inner surfaces of the pair of substrates to align and form a shutter portion together with the liquid crystal. The present invention is characterized by comprising a liquid crystal shutter and a drive circuit provided at least at -1 of a pair of substrates of the liquid crystal shutter and supplying a drive signal for driving the shutter portion to the electrode.

[Embodiment of the Invention] An embodiment of the liquid crystal shutter device of the present invention will be described below with reference to drawings.

1 and 2 show enlarged views of the liquid crystal shutter device. To explain the liquid crystal shutter 1, 11 in the figure
1 is a signal electrode substrate, 12 is a common electrode substrate, and these pair of substrates 11 and 12 are formed of transparent glass plates.
1 is wide in order to provide a drive circuit. Board 1
1.12 are arranged vertically facing each other and are bonded together with a sealing material 13. - A large number of signal electrodes S are arranged in the longitudinal direction of the substrate 11 at the center of the inner surface thereof.

This signal electrode S has two shutter electrodes 14.14 commonly connected by a transparent electrode on the inner surface of the substrate 1 and a lead electrode 15 connected to the -1 shutter electrode 14, and a connecting part of the shutter electrode N14m14. and lead electrode 1
A metal film 16f is formed on the surface of the metal film 5.

Then, the shutter electrodes 14 of each signal electrode S...,
14... are arranged along the substrate length direction in the opposing gap between the substrates 1.2, and the lead electrodes 15... of each signal electrode S... They are arranged in such a way that they are led out alternately on the left and right. That is,
The lead electrodes 15... of the signal electrodes S... located every other signal electrode S... are led out to one side of the substrate 1, and the other one and one! Signal electrode S° located at...
Lead electrodes 15-... are led out to the other side of the substrate 1. On the inner surface of the other substrate 2, two band-shaped common electrodes C2 and C are arranged in parallel along the length direction of the substrate with a minute interval between them. The common electrode C includes a transparent electrode 17 formed on the inner surface of the substrate 2, a metal film 18 formed on the surface of this transparent electrode 11, and the signal electrodes S...
The metal film 1 in the portion corresponding to the shutter electrode 14-...
A large number of shutter electrodes 19 . . . are arranged and formed by opening the st-opening and exposing the transparent electrode 17. That is, two rows of shutter electrodes 19 are formed by two common electrodes C1C.

19-- are arranged along the length direction of the substrate.

Further, the shutter electrode 14 is provided in the opposing gap between the substrates 1.2 and 1.2.
..., 14..., 19..., 19..., and a liquid crystal 20 is formed in the gap between the substrates 1.2 surrounded by the sealing material 13. For example, a nematic liquid crystal containing an optically active substance or a nematic liquid crystal containing a dichroic dye dissolved therein is sealed. And the shutter electrodes 14..., 14 of the signal electrodes S...
. . . and shutter electrodes 19 . . . of the common electrode C9C facing each other and the liquid crystal 20 present between both electrodes to control the original transmission.
A... is constructed, and these shutter parts A..., A...
... are arranged in the length direction of the substrate.

In the liquid crystal shutter 1 configured in this manner, a plurality of integrated circuits (ICs) 22m...21h are provided on the inner side and the other side of the substrate 110 for signal electrodes, respectively.

211...21p are provided at intervals in the length direction of the substrate. These integrated circuits 21a...21h, 2
11...21p are constructed by incorporating a drive circuit for supplying drive signals to the signal electrodes S... of the substrate 11. Each integrated circuit 21a provided on one side of the board J1.
...21h are connected to the lead electrodes 15... of the plurality of signal electrodes S... each led out to one side of the substrate 1.
The integrated circuits 211...21p provided on the other side are respectively connected to leads JrIL poles 15... of a plurality of signal electrodes S... provided in the S section. Note that the integrated circuits 211...zrb, 211...21p have connecting terminals (not shown) connected to half [8 bumps 26? Each lead is connected by soldering! The connection is fixed with @15... Furthermore, the inner and side surfaces of the fj board J1 are used to supply various signals and power. A few leads 22...? i! ir
i. The leads 22... are arranged in parallel along the length direction, and the leads 22... are installed at the -fII section of the FiIII board 1, and are branched at points corresponding to each fast tank circuit 21%...2JhK.
%S product circuits 21m--21h are connected to this branch. A plurality of external terminals ZS-... are formed on the side edge of one part of the substrate 11 at intervals in the length direction of the substrate, and each of these external terminals 23... is connected to each lead 22...・corresponds to and continues as one. In addition, the leads 22... and the external terminals 23-... are transparent i? ! Gold tsytzs is formed on the surface of the other film 24. Furthermore, a plurality of layers 2 are similarly formed inside other parts of crystal phase 1.
2-... are connected, and each of these signal supply leads 22...
・The branch W6 is provided on the other side of the substrate l.
11...21p are connected. Each of these signal supplies I
J-1-''22... are formed to cross in the width direction at one end of the substrate 11 and are integrally connected to each of the external terminals 23-.
h, 211...21 p leads the connection terminal 22-.

22... are connected and fixed by soldering using a solder pan f26. As a result, the external terminal 23...-lead 22...integrated circuit jJa...21p signal electrode S.
Lead electrode J5--Shutter electrode 14
""e14-'j: The connected electronic circuit is configured.

Note that each lead of a flexible sheet with leads formed thereon is connected to each external terminal 23 of the board 11 by soldering, and this flexible lead is connected to nine other drive circuit components provided externally. . To be sure, the common electrode C1C formed on the substrate 12 has a flexible lead connected to the end or both ends, and this flexible lead is connected to both ends connected to the external drive circuit component. The current flowing through one flexible lead is half that of when only one flexible lead is connected, which is advantageous in terms of reducing voltage drop.

Here, an example of a drive circuit for driving the liquid crystal shutter 1 t-
FIG. 3 will be explained. Note that this drive circuit is for the case where a liquid crystal shutter is used as the original writing head of the original writing printer. In the figure, 31 receives 4-turn data (transferred from an external device) and outputs print data for controlling the opening/closing of each shutter W6A corresponding to each dot of P4 turn, such as characters to be printed. In the control section, this print data control section has a page storage section 32 that stores one page of input Noreen data, and sequentially reads line data to be printed of the stored IP4 turn data and serially stores the data. The print data output from the read control unit 33 is transmitted to the integrated circuit 22 disposed on the signal electrode substrate 11.
It is connected to a drive circuit 34 made up of circuits 1 to 21p. Note that each part of the print data control section 31 operates in synchronization with the clock/timing pulse generated by the clock/timing pulse generating section 35.

The print data output of the print data control section 31 is the total number of shutter sections A (for example, when the print width is 250 sheets, 250 sheets are output).
0 pieces) and outputs the clock/timing pulse generator 3.
The signals are applied to serial input terminals of serial input/parallel output type shift registers 36m and 36b which operate in synchronization with clock 1 and clock 2 from 5, respectively. shift register 3
6 turtles.

The parallel outputs of the data latches 31a are operated by the latch clock input from the clock/timing signal generator 35, and have the same number of pits as the shift registers 36a*36b.

37b respectively provided delay means 431°4J
This circuit delays the odd-numbered dot data of bi print data output by a predetermined time.

The recording signal/9-turn signal generator 38 receives the signal from the clock/timing pulse generator 35 and generates an off pattern signal (high frequency signal) and an on/arm turn signal (low frequency signal). Yes, these off-pattern signals and off-pattern signals C are sent to the recording signal selector 39, respectively.
m, 39b. This recording signal selector 39h
, 39b include data latches 37&, 37b and delay means 43 in addition to the off-pattern signal and on-pattern signal.
&.

Data corresponding to each pit of 43b and a selector signal from the clock/timing signal generator 35 are input.

The output of the recording signal selectors 39m and 39b is a segment driver 40 equipped with a level shifter and a driver.
*, 40b, and this segment driver 41
7 a e 40 b K is supplied with 5V and -20V power from the power supply section 41, and its output is connected to the liquid crystal shutter 1.
is applied to each signal electrode S..., respectively.

The signal from the clock/timing signal generator 35 is also supplied to the common driver 42, and the common driver 42 is supplied with 5V and -20V power from the power supply 41, and its output is applied to each of the liquid crystal shutters 1. are respectively applied to a common electrode.

The power supply unit 41 generates a 5V power supply for operating each logic element of each electronic circuit and a 20V power supply voltage for applying to the liquid crystal of the shutter gA, and the 5V power supply is used for the electronic circuit. Supplied to each part.

The aforementioned shift registers 36*, 36b, data latches 37*, 37b, delay means 431, 43b, recording signal selectors 39m, 39b, and segment drivers 40*, 40b correspond to the plurality of groups of signal electrodes. A plurality of integrated circuits 21h to 21h, 211 to
It is formed by dividing 21 pK and arranged on the signal electrode substrate 11. That is, in this embodiment, the signal electrode S...
The 625 lead electrodes 15 led out to one side of the substrate 11 on which the lead electrodes 15 are formed are divided into 7 groups of 8° lead electrodes 15 and 65 lead electrodes 15 .
The lead electrodes 15 of each group are divided into 8 integrated circuits 21.
Connected to 1-2Zh. The signal electrode substrate 11
625 lead electrodes 15 led out to the other side of the...
・Ke-#JI-Life-Advance to the individual of the beak and lead electrode 15・
. . . Similarly, the lead electrodes 15 . . . are divided into seven groups of 80 groups and one group of 65 lead electrodes 15 . are connected to eight integrated circuits 211 to 21p, respectively. In addition, these 8 integrated circuits! 21h
~21h, 211~21p shift registers have a series input end and a series output end connected to lead electrodes 151..., 15b.
... are sequentially combined, and each of these is 125
It operates as a 0-pit shift register.

The drive circuit 34 configured in this way has a liquid crystal shutter section A.
Assuming that one writing period is 2 m5 sec, the shutter in the first row of the liquid crystal shutter section A is selectively driven in the first half of 1 m sec, and the shutter in the second row is selectively driven in the second half of 1 m sec. The operation is explained below.

The page storage unit 32 stores one page of parable turn data transferred from an external device, and stores the stored parable turn data one page at a time.
The turn data is read out by the read control unit 33 as n (n is 1
The line data of .about.the number of last rows is read out within 2m5Ie, and the process is repeated from n=1 to the line data of the last row. Print data output, clock 1, clock 2Fi are output at the timing shown in Fig. 4, and the print data is output by shift register 36*, 2 data at a time,
I will give it to 36b separately. That is, the print data outputs DI, D2 . D5#D6, . . . are input to the shift register 36m, and print data outputs D3, D4, D7, D8, . . . are input to the shift register 36b by clock 2.

The shift registers 36 in the integrated circuit 21 each consist of 160 pits, with the first shift register having 160 pits.
When data that exceeds the pit is input, it is transferred to the next stage shift register one after another, pushing out the first data.In this way, the integrated circuits 211 to 21h, 221
160-bit data is read into the shift registers in the integrated circuits 21p and 21p, and 130-bit data is read into the shift registers in the integrated circuits 21h and Zip.

The dot data read into the shift registers 36h, 36b and corresponding to each shutter section A is transferred to the clock/timing noise generation section 35 after the reading is completed.
The data is read into the data latches 37* and 37b by a latch clock generated every 2m5ec. Data latch 37a*j7b outputs odd number data iA to slow flow means 43m and 43b, and even number data 1r:B
It is output to recording signal selectors 39a #39b as. That is, Di, D5... to the delay means 44m,
D2. D6... to the recording signal selector 39m, D3-
D7''・f delay means 4sh, D4, D8...
* is output to the recording signal selector 39b. Delay means 43
m and 4jb delay odd number data A and output it as delayed data A' to recording signal selectors 39m and 39b. The delay t is determined by the arrangement of the microshutters in the sub-scanning direction shown in FIG. 1. For example, if the size of the microshutters is 100μ and the center spacing is 250μ, it is sufficient to delay by two clocks.

The recording signal selectors 39* and 39b select the off pattern signal and the on/4 turn signal supplied from the recording tattle turn generation section 38 based on the dot data A' and B, and select the on/4 turn signal from the segment drivers 40 & 40b. supply to. The segment drivers 40m and 40b are supplied with a 20V power from the power supply section 41, and convert the voltage of the off-pattern signal or on-pattern signal to 25V, which is sufficient for the liquid crystal to operate. It is applied to each signal electrode S... -10,000, clock timing/? Based on the clock/timing noise generated by the pulse generator 35, the common driver 42 forms a common signal in which a high frequency signal and a low frequency signal are alternately repeated every 1 maee, and generates a common signal for the liquid crystal shutter l. Electrode C9
C. The common driver signals 42 are used to apply a first common signal to the common electrode C corresponding to the first row of the shutter section A, and a first common signal to be applied to the common electrode C corresponding to the first row of the shutter section A. A second common signal is generated to be applied to the corresponding common electrode C, and these common signals are such that the phases of the high frequency and low frequency are different from the phase of the segment signal.
It is a signal in which the period in which a high frequency is applied and the period in which a low frequency is applied are opposite to each other, and the voltage of the common signal is increased by 25% by the voltage supplied from the power supply section 41.
The voltage is converted to VK and applied to each common electrode C9C.

The liquid crystal shutter 1 to which the above-mentioned segment signals and common signals are applied has the shutter electrodes 14, J4-, etc. of the signal electrodes S when an off-pattern signal is applied to the signal electrodes S... Shutter electrode 1 of common electrode C
A high frequency voltage is applied between 9.19 and the shutter part A.
... is closed, and when the signal electrode S...K on-no-turn signal is applied, the shutter electrodes 24, 144-. of the signal electrode S and the shutter electrodes 19, 19-. of the common electrode C are closed. A low frequency voltage is applied between the shutter parts A and the shutter section A, and the shutter section A is opened. And the shutter part A.
The first and second rows of ... are alternately and independently controlled to open and close every lm s@e, and the light from the light source 5 is controlled nine times in response to pattern data input from an external device. The light serves as a starting point and is irradiated onto the photosensitive drum.

In the liquid crystal shutter device of this embodiment, the integrated circuit 21a
. . 21b, 211 . The external terminals 23... are connected to the print data control section 31, the clock timing notarus generation section
, recording signal output generator 38, common driver 42
and connected to the power supply section 41.

When the nine liquid crystal shutter devices configured in this manner are used, the number of drive circuit components provided independently of the liquid crystal shutter 1 is reduced, and the number of connection conductors connecting these drive circuit components and the substrate 11 is also reduced. Therefore, when mounting a liquid crystal shutter device, the mounting structure is simplified, the mounting space is smaller, and the number of connection points with the flexible sheet that connects the drive circuit components and the liquid crystal shutter is reduced. This also improves the reliability of the connection between the two.

FIG. 5 shows an example in which the liquid crystal shutter device of this embodiment is installed in the optical writing head of an optical writing printer.
The same parts as in FIG. 6 are given the same reference numerals. integrated circuit 21
The ten external terminals 23 formed on the signal electrode substrate 11 on which the terminals are mounted are connected to the interface substrate 45 by a flexible sheet 44 on which ten corresponding conductive leads are formed. . This interface board 45 is provided outside the optical writing head and is connected to electronic circuits such as the memory printing data control section 31 and the clock/timing generation section 35.

In this way, the optical writing head has a shift register 36*
, 36b and the like is not required separately, this optical writing head can be made extremely compact.

In the above embodiment, an integrated circuit for driving the signal electrode is placed on the signal electrode substrate, but the present invention is not limited to this, and an integrated circuit for driving the common electrode is placed on the signal electrode substrate. You can also. In this case, the output terminal of the common electrode driving integrated circuit on the signal electrode substrate and the common electrode on the common electrode substrate are electrically connected by interposing a conductor between the substrates. Moreover, without providing a special integrated circuit for common electrodes, by incorporating them into a part of a plurality of integrated circuits for signal electrodes and connecting their outputs in parallel,
It is also possible to increase the current capacity and drive the common electrode T-drive. Furthermore, the integrated circuit has only a portion of the common electrode substrate Ki
! ll! Alternatively, it may be provided on both substrates. The method of driving the liquid crystal shutter is not limited to two-frequency driving.

[Effects of the Invention] As described above, according to the present invention, when mounting a liquid crystal shutter, the structure can be simplified and downsized, and the connection reliability between the liquid crystal shutter and drive circuit components can be improved.

[Brief explanation of drawings]

1 and 2 show an embodiment of the liquid crystal shutter device of the present invention, FIG. 1 is a plan view, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is a liquid crystal shutter device according to an embodiment of the present invention. FIG. 4 is a circuit block diagram showing an example of a drive circuit. FIG. 4 is a timing chart showing the operation of the circuit block shown in FIG. 3. FIG. 5 is a circuit block diagram showing an example of the drive circuit. FIG. FIG. 6 is a sectional view showing a conventional liquid crystal shutter device. 1...Liquid crystal shutter, 11.12...Substrate, 21.
... integrated circuit, S ... signal electrode, C ... common electrode,
34... Drive circuit, A... Shutter section. Applicant's representative Patent attorney Takehiko Suzue Figure 4 Figure 5

Claims (2)

[Claims] (1) A liquid crystal shutter comprising a pair of substrates facing each other with a liquid crystal in between and electrodes formed on the inner surfaces of the pair of substrates to align and form a shutter section together with the liquid crystal; A liquid crystal shutter device comprising: a drive circuit provided on at least one of the substrates and supplying a drive signal for driving the shutter section to the electrode. (2) The liquid crystal shutter device according to claim 1, wherein the drive circuit is constituted by an integrated circuit.