JPH10272805A - Image exposing method using two-dimensional matrix type space optical modulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove the influence by the DC component in each pixel part by a method wherein counter-polar DC voltages are applied to every pixel part in the exposure of a photosensitive material by irradiating exposing lights, which are modulated at every pixel part arranged in a two-dimensional matrix-fashion by means of space optical modulator. SOLUTION: The light emitted from a light source 3 is focused by a condenser 4 and incident in a polarized light beam splitter (henceforth expressed as a PBS) 2. An S polarized light wave among these rays of light incident is reflected at the PBS 2 so as to be incident in a two-dimensional space optical modulator 1 in order to be reflected at pixel electrodes through a liquid crystal layer, resulting in being incident in the PBS 2 by passing through the liquid crystal layer again. At this time, only the P polarized light wave of the reflected light passes through the PBS 2 so as to form an image on a photosensitive material 7 through a projecting lens 6. In this case, under the condition that the pixel parts are set for the predetermined time under an ON state, under which an exposing light is outputted, a DC voltage, the absolute value of which is nearly equal to that of an applied DC voltage and the polarity of which is opposite to that of the applied DC voltage, is applied during the period except the On state so as to remove the influence by the DC component in the pixel parts, to which the exposing light is applied during their exposure period.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for imagewise exposing a photosensitive material using a two-dimensional matrix type spatial light modulator composed of a liquid crystal element or the like, and more particularly, to a method of exposing a photosensitive material to a spatial light modulator. The present invention relates to an image exposure method capable of removing the influence of a DC component.

[0002]

2. Description of the Related Art In recent years, an image is reproduced by exposing a photosensitive material, for example, a silver salt sensitive material, a non-silver salt based photoreactive coloring sensitive material, a photothermal conversion coloring sensitive material, etc., with light modulated based on image data. Printer devices have been developed in various ways. One of the performances required for such a printer device is to increase the exposure speed.

As a general exposure method, a method using laser scanning exposure is known. However, this method is a dot-sequential exposure operation, and has a disadvantage that the exposure time is long.
As a method suitable for higher-speed exposure, an exposure method using a line-type light modulation element or a two-dimensional matrix-type light modulation element is known. The former is a line-sequential exposure operation, and enables high-speed exposure. The latter is a surface exposure operation,
The two-dimensional matrix type light modulation device, which can be expected to perform high-speed exposure, has a pixel portion whose light modulation state changes according to a drive signal, is arranged in rows and columns and arranged in a two-dimensional matrix. As one of such spatial light modulators, there has been known a device including a pixel portion that maintains a light modulation state until a new drive signal is input. This type of spatial light modulator has been developed and commercialized as a high-quality display device. In particular, a display element of an active matrix type liquid crystal element is a typical example.

In this type of spatial light modulator, it is desired that the area of the element be as small as possible in order to increase the light collection rate in the surface exposure process. In order to obtain a higher quality image, it is necessary to increase the number of pixels of the element.
However, when the area of the element is reduced and the number of pixels is increased, the area of one pixel is naturally reduced. Therefore, high definition of the element is required.

[0005] From such a background, among the aforementioned active matrix type liquid crystal elements, the substrate and the pixel circuit (mainly switching elements such as MOS-FETs and signal holding circuits, memories such as SRAM circuits, digital circuits)
And a peripheral drive circuit (mainly a row selection drive circuit and an image signal drive circuit in a column) are integrally formed of a single crystal semiconductor,
A reflective active matrix liquid crystal element having a configuration in which a reflective electrode is provided above the pixel circuit to supply a voltage to the liquid crystal is particularly preferable in terms of high integration and high aperture ratio.

On the other hand, among the active matrix type liquid crystal elements, those using ferroelectric liquid crystal as a liquid crystal material have high-speed response (the response time depends on the liquid crystal material, voltage applied to the liquid crystal, temperature, etc.). , Several μs to 100 μs
Therefore, it is very expected as an exposure element for a printer device.

The active matrix type light modulation device using the ferroelectric liquid crystal can basically perform static drive (drive always applying a desired voltage to the liquid crystal layer), and the liquid crystal itself necessarily has a memory property. There is no need, and writing can be performed more stably and at higher speed.

Here, image exposure by a two-dimensional matrix type light modulating element using a ferroelectric liquid crystal in a light modulating section will be described in detail.

[0009] 2-dimensional matrix type light modulation structure diagram 1 of the device, a cross-sectional view of a pixel portion of the spatial light modulator of this kind. As shown here, an n-MOS-FET 11 and a charge storage capacitor Cstg 12 are formed on a single crystal p ^- type silicon semiconductor substrate 10. n-MOS-FET11 is n
⁺ Type drain region 13, source region 14, gate oxide film 1
5, and a gate electrode 16 made of a poly-Si film. Further, the charge storage capacitance Cstg 12 is a p ⁺ region 17,
It is composed of an oxide film 18 and a poly-Si film 19.

Also, the first layer A is interposed via the first interlayer insulating film 20.
An l wiring 21 is formed, thereby forming a source electrode 22 connected to the source region 14. This source electrode
22, the pol of the source region 14 and the charge storage capacitor Cstg 12
The y-Si film 19 is connected. Note that a drain electrode 23 is connected to the drain region 13. Further, a pixel electrode (second layer Al) 25 is formed via a second interlayer insulating film 24, and is connected to the source electrode 22.

An alignment film 26 is formed on the pixel electrode 25. On the other hand, a counter transparent common electrode 28 made of ITO is formed on one side of the counter transparent substrate 27, and an alignment film 29 is further formed thereon.
Are formed. The two substrates 10 and 27 are arranged such that the alignment films 26 and 29 integrated therewith face each other,
The ferroelectric liquid crystal 30 is held in the gap.

FIG. 2 is an equivalent circuit of a pixel portion of the spatial light modulator of FIG. As shown, the source electrode 22 of the n-MOS-FET 11, one of the charge storage capacitors Cstg 12, and the pixel electrode 25 are connected. The other end of the charge storage capacitor Cstg12 is connected to the power supply ground potential Vss of the element. A capacitor Clc is formed by the pixel electrode 25, the alignment films 26 and 29, the ferroelectric liquid crystal 30, and the opposing transparent common electrode 28.

Here, based on the power supply ground potential Vss,
The gate electrode voltage of the n-MOS-FET 11 is Vg, the drain electrode voltage is Vd, the source electrode voltage is Vs, and the opposing transparent common electrode voltage is Vcom. Also, the pixel electrode voltage is set to the liquid crystal layer voltage Vlc based on Vcom.

FIG. 3 shows the basic operation of the spatial light modulation device.
1 shows a schematic light modulation optical system. A polarizing beam splitter (PB) is provided on the opposite transparent substrate side of the spatial light modulator 1.
S) 2 is arranged. The light from the light source 3 is S
The polarized wave is reflected, and the opposing transparent substrate 27 of the spatial light modulator 1 is reflected.
Incident on. The incident light passes through the pixel electrode through the layer of liquid crystal 30.
The light is reflected by 25 and again enters the PBS 2 through the liquid crystal layer. At this time, only the P-polarized wave component of the reflected light is
And the light becomes output light.

FIG. 4 shows the relationship between the liquid crystal layer voltage Vlc and the liquid crystal alignment position for explaining the basic operation of the spatial light modulator. As the liquid crystal, a ferroelectric liquid crystal exhibiting bistable orientation is used. The liquid crystal layer voltage Vlc is -V
When lcs, the liquid crystal alignment direction coincides with the incident polarization axis, and when the liquid crystal layer voltage Vlc is Vlcs, the liquid crystal alignment direction is shifted from the incident polarization axis.
An orientation process is performed so that the position is 45 degrees. The liquid crystal material and the thickness of the liquid crystal layer are appropriately adjusted so that desired output light is obtained when the liquid crystal alignment direction is at a position at 45 degrees from the incident polarization axis.

In this manner, the output light is turned off when the liquid crystal layer voltage Vlc is -Vlcs, and turned on when the liquid crystal layer voltage Vlc is Vlcs.
Becomes

FIG. 5 shows each voltage of the pixel portion and the waveform of output light in the configuration described with reference to FIGS. First, the gate electrode voltage Vg is set to a sufficiently high Vgon so that the n-MOS-FET 11 becomes conductive. At the same time, when the drain electrode voltage Vd is set to Vd (on), the pixel voltage Vs becomes approximately Vd.
d (on). Thereafter, even if the gate electrode voltage Vg is set to a sufficiently low Vgoff so that the n-MOS-FET 11 is turned off, the pixel voltage Vs is maintained at approximately Vd (on) by the charge storage capacitance Cstg12 and the liquid crystal layer capacitance Clc. . Therefore, the liquid crystal layer voltage Vlc during this period (FIG. 5 (a)) is Vlc = (Vd
(on) -Vcom).

On the other hand, when the gate electrode voltage Vg is made sufficiently high so that the n-MOS-FET 11 is turned on and the drain electrode voltage Vd is made Vd (off) at the same time, the pixel voltage Vs
Is approximately Vd (off). Thereafter, even if the gate electrode voltage Vg is sufficiently reduced so that the n-MOS-FET 11 becomes non-conductive, the pixel voltage Vs is kept substantially at Vd (off) by the charge storage capacitance Cstg and the liquid crystal layer capacitance Clc. Therefore, the liquid crystal layer voltage Vlc during this period (FIG. 4 (b)) is approximately Vlc = (V
d (off) −Vcom).

Here, when the common electrode voltage Vcom is applied so that Vcom = (Vd (on) + Vd (off)) / 2, the liquid crystal layer voltage Vlc in each of the periods (a) and (b) becomes (a) Period: Vlc = (Vd (on) −Vd (off)) / 2 (b) Period: Vlc = − (Vd (on) −Vd (off)) / 2. At this time, the liquid crystal layer voltage V during the periods (a) and (b)
Vd (o) so that lc is not less than Vlcs and not more than -Vlcs, respectively.
n) and Vd (off), the output light is ON and OF
It is possible to modulate with F.

In practice, the liquid crystal layer voltage Vlc may be asymmetric between the periods (a) and (b) due to the parasitic capacitance of the n-MOS-FET 11 or the like. Since there is no influence, Vlc follows the above equation.

Here, Tr in FIG. 5 is the optical response time of the ferroelectric liquid crystal, which generally depends on the liquid crystal material, liquid crystal layer voltage Vlc, temperature, etc., but practically several μs. ~ 1
About 00 μs can be obtained. The time for writing data to the pixel is determined by changing the liquid crystal layer voltage Vlc to the liquid crystal operating voltage Vlcs (or −
Vlcs) and the optical response time of the liquid crystal. In order to write data at high speed, it is necessary to shorten both of these times, but the optical response time of the liquid crystal is practically limited.

Two-dimensional matrix driving method of spatial light modulator
Act 6 is an equivalent circuit of the two-dimensional matrix spatial light modulation element. This example is a spatial light modulator having m columns × n rows of pixels, and is composed of an m columns × n rows of pixel circuits, a row selection drive circuit that supplies signals to the pixel circuits, and an image signal drive circuit. ing. The image data is transferred to the image signal drive circuit, and a sequence described later is satisfied by the control signal and each drive circuit. Here, the gate electrodes of the pixels in the same row are connected together, and each is controlled by a row selection signal [Vg1, Vg2,..., Vgn] which is an output of the row selection drive circuit. Also, the drain electrodes of the pixels in the same column are connected together, and the image signals [Vd1, Vd1,
d2..., Vdm].

Incidentally, m columns × n shown in the equivalent circuit of FIG.
The row pixel circuits, and the row selection drive circuit and the image signal drive circuit are formed on the same silicon substrate.

FIG. 7 is a timing chart showing a method of driving the two-dimensional matrix spatial light modulator in the circuit of FIG. Hereinafter, a writing sequence of an image signal for one screen will be described.

A) The image signal to be written to the pixels in the first row is
It is supplied from the outputs [Vd1, Vd2..., Vdm] of the image signal drive circuit. Next, only the first row selection signal Vg1 is set to Vgon at which the MOS-FET is turned on, and the other row selection signals are set to Vgoff at which the MOS-FET is turned off. At this time, each image signal voltage is applied to the pixel electrodes in the first row. Then Vg1
Is set to Vgoff at which the MOS-FET becomes non-conductive, the voltage of the pixel electrode is kept almost unchanged. The output light responds as shown in FIG. 5 according to the pixel voltage. Thus, the image signal writing of the pixels in the first row is performed. This one
The writing time for a row is assumed to be τ.

B) Image signals are written in the same sequence in the second and subsequent rows. When the writing of the image signals in the nth row is completed, the writing of the image signals for one screen is completed. Therefore, the writing time T of the image signal for one screen (n rows)
f is n × τ.

Description of Exposure System FIG. 8 shows an exposure system for a photosensitive material using the above-mentioned reflection type two-dimensional matrix photonic spatial light modulator.

First, the light from the light source 3 is condensed by the condenser lens 4 and enters the PBS 2. The S-polarized wave of this light is reflected by the PBS 2 and is incident on the opposite transparent substrate side of the two-dimensional matrix light spatial light modulator 1. The incident light is reflected by the pixel electrode through the liquid crystal layer, passes through the liquid crystal layer again, and
It is incident on BS2. At this time, only the P-polarized wave of the reflected light passes through the PBS 2 as output light, and forms an image on the photosensitive material 7 by the projection lens 6. The two-dimensional distribution of the amount of light formed on the photosensitive material 7 follows the image signal written to the two-dimensional matrix light modulator 1 by the image signal generator 8. That is, as shown in FIG. 5 described above, the pixel voltage is Vd (on)
Is written, the light amount of the photosensitive material 7 at that portion is turned on, and when Vd (off) is written as the pixel voltage, the light amount of the photosensitive material 7 at that portion is turned off.

FIG. 9 shows an exposure sequence for the photosensitive material 7. First, the optical shutter 5 disposed after the condenser lens 4 is closed. In the meantime, the photosensitive material 7 is conveyed to the image forming surface of the projection lens 6 and fixed. At the same time, the two-dimensional matrix light spatial light modulator 1 is
The signal of Vd (off) is written to all the pixels. Thereafter, the optical shutter 5 is opened. At this time, the output light is entirely OFF.

In this state, the image signal generator 8 writes the image data signals (Vd (on) or Vd (off)) into the two-dimensional matrix light modulator 1 sequentially from the first row.
The output light is sequentially output according to the image signal, and exposes the photosensitive material 7. The writing time from the first row to the last n-th row is nτ. After writing the image signal in the last n rows,
The signal of Vd (off) is written from the first row again to turn off the output light. When the signal of Vd (off) is written in the last n-th row, the exposure period to the photosensitive material 7 ends. After that, the optical shutter 5 is closed, and the next photosensitive material 7 is conveyed.
Fixation is performed.

According to the above exposure sequence, the exposure time Te to the photosensitive material 7 is nτ when the image signal written to each pixel is ON, and is zero when the image signal is OFF. The time To required for this exposure is 2nτ.

That is, assuming that the writing time of one row is τ, the time To required for exposing an image of n rows and two gradations is 2nτ, and the exposure time Te to the photosensitive material 7 at this time is nτ. Here, the exposure period To includes a stabilization time when the shutter is opened and closed, but this time is ignored since it is very small compared to nτ.

[0033]

Here, as can be seen from the above description, a DC voltage according to image data is applied to the liquid crystal layer of each pixel during an exposure period for one screen. . That is, when the image data turns on the output light, the liquid crystal layer voltage Vlc is set to + Vlcs
Is applied, and when the image data turns off the output light, -Vlcs is applied as the liquid crystal layer voltage Vlc. Therefore, in the exposure method using the two-dimensional matrix type light modulation element in which the image data corresponds to the polarity of the liquid crystal layer voltage, the average value of the liquid crystal layer voltage during the exposure period does not become zero and the DC component does not become zero. Will remain.

It is also conceivable to apply a voltage having a polarity opposite to the voltage applied in accordance with the image data so that the average value of the liquid crystal layer voltage during the exposure period becomes zero. In addition, the photosensitive material is exposed to output light different from desired output light according to image data, which is not preferable.

It is known that when a DC component is applied to the liquid crystal layer voltage as described above, a problem occurs in the operation quality of a general liquid crystal including a ferroelectric liquid crystal. In particular, the DC component is 0.
After a certain period of time, which exceeds about 1 V, mobile carriers (impurity ions, electrons / holes, etc.) in the liquid crystal layer or the alignment film are polarized by the DC component.

The once-polarized movable carrier has a slow relaxation rate even when an electric field of the opposite polarity is applied to relax the polarization, and the internal electric field due to the polarization is present in the liquid crystal layer until it is completely relaxed. become. Due to the presence of the internal electric field, there arises a problem that, even when a normal control voltage is applied to the liquid crystal layer, a desired operation cannot be obtained because the effective electric field is different from the electric field due to the control voltage. Especially in the case of ferroelectric liquid crystal,
There arises a problem that the response time changes due to the internal electric field parasitic from the polarization.

In some cases, polarized carriers are permanently present due to trapped polarized carriers at each layer interface or inside, and a space charge distribution is formed on the liquid crystal layer plane, causing in-plane operation unevenness. Deterioration over time easily occurs.

The present invention has been made in view of the above circumstances, and an image using a two-dimensional matrix type spatial light modulator capable of removing the influence of a DC component in a pixel portion applied during an exposure period. An object of the present invention is to provide an exposure method.

[0039]

According to the present invention, there is provided an image exposure method using a two-dimensional matrix type spatial light modulator, wherein a pixel portion comprising a liquid crystal layer or the like whose light modulation state changes according to an applied voltage is two-dimensional. While being arranged in a matrix,
A spatial light modulation element including a circuit for updating and maintaining the light modulation state of each pixel portion is arranged in the optical path of the exposure light, and the photosensitive material is irradiated with the exposure light modulated for each pixel portion by the spatial light modulation element. An image exposing method using a two-dimensional matrix type spatial light modulator for exposing the photosensitive material, wherein a DC voltage having a polarity opposite to that of the DC voltage is applied to each of the pixel portions. Things.

The DC voltage of the opposite polarity may be applied outside the exposure period after applying the DC voltage and modulating the exposure light according to the liquid crystal operation mode or the like, or may be applied during this exposure period. May be.

It is desirable that the DC voltage has an absolute value substantially equal to the DC voltage for exposure light modulation, and is applied for a time substantially equal to the application time of the DC voltage for exposure light modulation.

More specifically, for example, when the pixel portion is set to the ON state for outputting the exposure light for a predetermined period of time, the DC voltage of the opposite polarity is used during a period other than the ON period.
A DC voltage having an absolute value substantially equal to the applied DC voltage for setting the N state and having the opposite polarity is applied to the pixel portion for a time substantially equal to the ON state setting time, so that the pixel portion is set to the OFF state where the exposure light is not output. When the predetermined time is set, during the period other than the OFF state, the DC voltage having an absolute value substantially equal to the applied DC voltage for setting the OFF state and having a reverse polarity is applied to the pixel portion for a time substantially equal to the OFF state setting time. Is applied.

In addition, when the pixel section is set to the ON state for outputting the exposure light for a predetermined time, the applied DC voltage for setting the ON state is substantially equal to the absolute value during the period other than the ON state. When a DC voltage having a reverse polarity is applied to the pixel unit for a time substantially equal to the ON state setting time, and the pixel unit is set to the OFF state in which the exposure light is not output for a predetermined time, almost 0 V during periods other than the OFF state May be applied to the pixel portion for a predetermined time.

Further, the process of applying the DC voltage of the opposite polarity may include a process of always applying substantially 0 V regardless of the ON state and the OFF state of the pixel portion.

On the other hand, in the above-described image exposure method, a shutter capable of opening and closing the optical path of the exposure light to the photosensitive material is provided, and a period during which a DC voltage having a polarity opposite to that of the DC voltage is applied,
It is desirable to keep this shutter closed.

Further, in the image exposure method using another two-dimensional matrix type spatial light modulator according to the present invention, the pixel portion whose light modulation state changes in accordance with the applied voltage is formed in a two-dimensional matrix in the same manner as the above method. A spatial light modulation element provided with a circuit for updating and maintaining the light modulation state of each pixel portion is disposed in the optical path of the exposure light, and the exposure light modulated by the spatial light modulation element for each of the pixel portions is provided. In an image exposure method using a two-dimensional matrix-type spatial light modulator that irradiates light to a photosensitive material to expose the photosensitive material, in each of the pixel units, a DC voltage is applied to modulate exposure light. An AC voltage is applied outside the subsequent exposure period.

Also in this case, it is desirable to provide a shutter capable of opening and closing the optical path of the exposure light to the photosensitive material, and to close the shutter during the period of applying the AC voltage.

In each of the above methods, the pixel portion whose light modulation state changes in accordance with the applied voltage is made of a ferroelectric liquid crystal, and among those, a pixel portion having a memory property in at least one alignment direction is particularly preferred. A liquid crystal composed of a dielectric liquid crystal can be suitably used.

As a circuit for updating and maintaining the above-mentioned light modulation state, a circuit composed of an element containing a single crystal semiconductor, a circuit composed of an element containing a polycrystalline semiconductor, and an amorphous semiconductor can be used. An element composed of an element including the like can be preferably used.

On the other hand, in the above-described method, it is possible to irradiate the photosensitive material with exposure light whose irradiation time is controlled for each pixel portion of the spatial light modulation element, thereby exposing the photosensitive material to multiple gradations.

At this time, all the rows of the spatial light modulator are selectively scanned at a plurality of different time intervals, and a DC voltage based on image data is applied to each pixel portion in the selected row. It is desirable to temporally multiplex the selection scans performed for each of the plurality of different time intervals, and to determine one selected row by time division from the plurality of different rows that have received the multiplex scan.

The plurality of time intervals are desirably a geometric progression of 2: 1: 2:...: 2 ^(g-1) {g is a positive integer}.

Further, it is desirable that the above-mentioned row selection be performed at a basic cycle gτ, where τ is the row selection time and g is the number of intervals.

[0054]

According to the image exposure method of the present invention, a DC voltage is applied to each of the pixel portions comprising a liquid crystal layer or the like of a spatial light modulation element to modulate the exposure light, and then the polarity opposite to the DC voltage is applied. By applying the DC voltage or the AC voltage, the DC component applied in the pixel portion during the exposure period is canceled, and the influence of the DC component can be removed.

Further, since the application of the above-mentioned DC voltage or AC voltage of the opposite polarity is performed outside the exposure period, output light is generated during the exposure period due to the application of these voltages, whereby the photosensitive material is exposed. No material is exposed.

[0056]

Embodiments of the present invention will be described below in detail with reference to the drawings.

<First Embodiment> FIG. 10 shows a first embodiment of the present invention.
6 is a diagram illustrating a timing of a row selection signal and a scanning timing line in the embodiment. In the figure, the horizontal axis is the time axis, and the vertical axis is the row selection signal (Vg1, Vg1 in order from the top).
g2,..., Vgn). In FIG. 10, a solid line indicates a scanning timing line (image data writing), and symbolizes the timing of the image data writing row selected by the row selection signal. The broken line indicates a scanning timing line (OFF writing), and symbolizes the timing of the OFF writing row selected by the row selection signal.

Here, for example, the spatial light modulator shown in FIG. 1 is used as the spatial light modulator, the driving circuit shown in FIG. 6 is used, and the exposure system shown in FIG. 8 is used. Can be used.

FIG. 11 is a diagram showing an exposure sequence including correction of a DC component in the present embodiment. In this case, the recording gradation is two gradations. An entire cycle of performing one exposure (two gradations) on one photosensitive material is defined as an exposure sequence cycle Tt. This exposure sequence period T
t is divided into periods T1, T2 and T3. Below the scanning timing line diagram, an example of the liquid crystal layer voltage Vlc of each row is shown. Here, it is assumed that the liquid crystal layer voltages Vlc of all the pixels are −Vlcs (OFF) at the beginning of the sequence.

The period T1 is a period during which the photosensitive material is exposed, which is referred to as an exposure period To. In the first half of period T1,
Image data is written in accordance with a scanning timing line (thin solid line). Assuming that one screen has n rows and the writing time of one row is τ, the writing time Tf of the image data is nτ. At this time, the liquid crystal layer voltage Vlc when the gradation [0] (output light OFF) is written in the pixels in the first row is −
Vlcs, and the liquid crystal layer voltage Vlc when the gradation [1] (output light ON) is written is + Vlcs. In the pixels on the n-th row, since no image data is written, the liquid crystal layer voltage Vlc is -Vlcs, which is the initial value for both the gradation [0] and the gradation [1].

In the latter half of the period T1, OFF is sequentially written to all rows in accordance with the scanning timing line (thick broken line). At this time, the liquid crystal layer voltage Vlc of the pixels in the first row is -Vlcs for both the gradation [0] and the gradation [1]. In the pixel of the n-th row, the liquid crystal layer voltage Vlc is -Vlc when the gradation is [0].
s, and at gradation [1], the liquid crystal layer voltage Vlc is + Vlcs
It is. As described above, in the exposure period To, the liquid crystal layer voltage Vlc differs depending on the row and the gradation, and the DC component may remain.

The period T2 and the period T3 are the DC voltage removal period T
c, that is, a period in which a voltage for canceling the DC component of the liquid crystal layer voltage Vlc during the exposure period To is applied. First, period T2
In the first half, the inverted data of the image data written in the period T1 is written in accordance with the scanning timing line (thin broken line).

Next, in the latter half of the period T2, ON is sequentially written to all rows in accordance with the scanning timing line (thick solid line). Further, in the first half of the period T3, ON is sequentially written to all rows in accordance with the scanning timing line (thick solid line). Next, in the latter half of the period T3, OFF is sequentially written to all rows in accordance with the scanning timing line (thick broken line). As a result,
In the exposure sequence cycle Tt (= T1 + T2 + T3), the liquid crystal layer voltage Vlc is applied to each row regardless of the gradation.
Is zero, and the remaining DC component is removed.

FIG. 12 is a diagram showing the relationship between the DC component correction timing and the exposure system drive timing in the present embodiment. The upper part of the figure shows the drive timing of the spatial light modulator with the correction period shown in FIG. On the other hand, the lower part of the figure shows the drive timing of the exposure system shown in FIG. In the exposure period To, the photosensitive material 7 is fixed and the shutter 5 is open. On the other hand, in the DC voltage removal period Tc, the shutter 5 is closed, and the photosensitive material 7 is conveyed. In this example, the DC voltage removal period Tc = 2To, but the time efficiency of the system can be improved by allocating the period Tc to the transport period of the photosensitive material 7.

<Second Embodiment> Next, the second embodiment of the present invention in which the exposure sequence period Tt is shortened compared to the first embodiment.
An embodiment will be described. FIG. 13 shows characteristics (response of liquid crystal layer voltage and output light) of the ferroelectric liquid crystal in the second embodiment. As the characteristics of the ferroelectric liquid crystal, it is desirable that at least one of the alignment states has a memory property (a property of maintaining the alignment state stably without applying an external voltage to the liquid crystal layer). Further, in the alignment direction having the memory property, the output light is turned off.
The alignment process and the output optical system are set so that

Under these conditions, when the liquid crystal layer voltage Vlc is set to + Vlcs in the period Ton, the output light is instantaneously turned ON, and the ON state is stably maintained while the voltage is applied. When the liquid crystal layer voltage Vlc is set to 0 V during the period Tm-on, when the memory property of the ferroelectric liquid crystal exists (bistability), the ON state is stably maintained as shown by the solid line in the figure.

When the memory property of the ferroelectric liquid crystal does not exist (hemi-stable), the state changes from ON to OFF as shown by the broken line in the figure. During the period Toff, the liquid crystal layer voltage V
When lc is -Vlcs, O is instantaneous regardless of the previous state.
It becomes FF and keeps the OFF state stably while the voltage is applied. During the period Tm-off, the liquid crystal layer voltage Vlc is set to 0V.
In any case, at least the OFF state has a memory property in the orientation method, so that the OFF state is always maintained stably.

A plurality of types of writing can be performed by utilizing the characteristics of the liquid crystal as described above. FIG. 14 shows the relationship between the type of writing and the applied liquid crystal layer voltage. First, in [image data] writing, the liquid crystal layer voltage Vlc is set to 0 V when the gradation is [0] (output light is off during the exposure period). When the gradation is [1] (the output light is ON during the exposure period), the liquid crystal layer voltage Vlc is set to + Vlc.
s. In the [inverted data] writing, the liquid crystal layer voltage Vlc is set to 0 V when the gradation is [0], and the liquid crystal layer voltage Vlc is set to -Vlcs when the gradation is [1]. That is, a voltage having a polarity opposite to the voltage applied in writing [image data] is applied. In the [state maintaining] writing, the liquid crystal layer voltage Vlc is set to 0 V at the gradation [0], and the liquid crystal layer voltage Vlc is set to 0 V also at the gradation [1]. That is, the current situation is maintained.

FIG. 15 is a view showing an exposure sequence including correction of a DC component using the above-described write mode. The upper part of the figure shows the scanning timing of each writing mode, and the lower part of the figure shows the liquid crystal layer voltage Vlc in the gray scale [0] and the gray scale [1] in the first and last n rows.

The period T1 is an exposure period To, and in the first half, writing of [image data] is performed according to a scanning timing line (thin solid line). In the latter half of the period T1, writing of [inverted data] is performed according to a scanning timing line (thin broken line). The period T2 is a DC voltage removal period Tc, and writing of [state maintenance] is performed according to the scanning timing line (thick broken line). The liquid crystal layer voltage Vlc in each period is set according to the relationship described with reference to FIG.

As a result, the exposure sequence period Tt (= T
In 1 + T2), the average value of the liquid crystal layer voltage Vlc becomes zero in each row regardless of the gradation, and the remaining DC component is removed. In the second embodiment, Tc
= To / 2, and the exposure sequence cycle Tt of the first embodiment can be further reduced. Of course, this second
Also in the embodiment, the time efficiency of the system can be improved by allocating the period Tc to the period for transporting the photosensitive material.

<Third Embodiment> Next, an image exposure method according to a third embodiment of the present invention will be described. FIG.
FIG. 11 is a diagram illustrating a relationship between a drive timing of a spatial light modulator and a drive timing of an exposure system according to a third embodiment. In this embodiment, the exposure sequence cycle T
t is composed of a period T1 and a period T2.
Is the exposure period To as described in the first and second embodiments. The period T2 is a period Tc for removing the influence of the DC component in the exposure period To.

In the period T2, an AC voltage having an appropriate amplitude and frequency is applied to the liquid crystal layer voltage Vlc. According to the experiments of the present inventors, it has been found that during the exposure period, the carrier polarization in the liquid crystal layer due to the DC component is sufficiently relaxed by applying an AC voltage having an appropriate amplitude and frequency to the liquid crystal layer for an appropriate time. ing. Here, the higher the amplitude of the AC voltage is, the greater the effect is, but it is preferably about 5 V to about 40 V. Further, the frequency is preferably about 50 Hz to 20 kHz. The AC voltage application time depends on the liquid crystal material, the orientation, the value of the DC component, the amplitude and the frequency of the AC voltage, and is 100 ms (millisecond) to several s.
(Second) is preferable.

Here, specific AC voltages to be applied are shown in FIGS. In the example shown in FIG. 17, the gate voltages (Vg1 to Vgn) of all the rows are MOS-FETs (see FIG. 6).
Is applied to turn ON. At this time,
Vd (on) and Vd are applied to the drain voltages (Vd1 to Vdm) of all columns.
The (off) voltage is applied alternately at a constant frequency fc. The voltage Vcom of the common electrode is substantially equal to Vd (on) and Vd
(off) intermediate potential. As a result, an AC rectangular wave having an amplitude Vlcs and a frequency fc can be applied as the liquid crystal layer voltage Vlc.

In the example shown in FIG. 18, the gate voltages (Vg1 to Vgn) of all rows and the drain voltages (Vd1 to Vd1) of all columns
dm) is the same as in the example of FIG. 17, but the voltage Vcom of the common electrode has the same amplitude as the drain voltage,
Apply a voltage of opposite phase at frequency. As a result, an AC rectangular wave having an amplitude of 2 Vlcs and a frequency fc can be applied as the liquid crystal layer voltage Vlc. That is, in this case, an AC voltage having twice the amplitude of the example in FIG. 17 can be applied at the same power supply voltage.

<Fourth Embodiment> Next, a fourth embodiment in which the present invention is applied to multi-tone exposure will be described. As a method for realizing multi-tone exposure using a light modulation element which takes a binary state such as a ferroelectric liquid crystal, there is known an exposure method in which an exposure time is changed within an exposure period on a photosensitive material. . In general, multi-tone exposure can be easily performed by performing exposure several times in the exposure period in the first embodiment described above.

However, this method has a problem that the total exposure period becomes extremely long as the number of gradations increases.
For example, if the number of gradations is 2 ^g (g is a positive integer), the writing time for one row is τ, and the number of rows is n, the total exposure period To
Becomes To = 2 ^g nτ [sec].

As a method for solving this problem, all the rows of the two-dimensional matrix type spatial light modulator are selectively scanned at a plurality of different time intervals, and each pixel portion in the selected row is based on image data. The selected scan performed at each of the plurality of different time intervals is temporally multiplexed, and one selected row is determined by time division from the plurality of different rows that have received the multiplexed scan. Is possible. Hereinafter, such a multi-tone exposure method will be described.

FIG. 19 is a timing chart of write scanning in this multi-tone exposure method. In FIG. 19, solid oblique lines (a), (b), and (c) are scanning timing lines for writing image data, and are dashed oblique lines (a).
Is a scanning timing line for writing OFF. Each scan timing line is scanned in order from the first row for each row. Scanning starts at image data write (a) → image data write (b) → image data write (c) → OFF write
It is performed in the order of (a).

Here, a solid scanning timing line (a)
And the time interval between the solid scanning timing line (b) and Tab,
Assuming that the time interval between the solid scanning timing line (b) and the solid scanning timing line (c) is Tbc, and the time interval between the solid scanning timing line (c) and the dashed scanning timing line (a) is Tca, The ratio is Tab: Tbc: Tca =
Set 1: 2: 4. Specifically, Tab: Tbc: Tca =
(3/7) nτ: Set to (6/7) τ: (12/7) nτ.
In this way, on any line 3 times of the image data writing scanning, it is possible to perform exposure of 8 gradations (2 ³ tones).

It should be noted that originally, writing scanning (row selection) of a plurality of rows cannot be performed simultaneously. Therefore, in actuality, the timing of the row selection signal performed according to the scanning timing lines (a), (b), and (c) corresponds to the periods (A), (B),
(C), and where the scanning timing lines overlap, row selection is performed in a time division manner in periods (A), (B) and (C).

FIGS. 20 and 21 show the relationship between the row selection signal timing and the scanning timing line at time t1 and time t2 in FIG. At time t1 immediately after the start of exposure in FIG. 20, writing scan is performed sequentially from the first row according to the scan timing line (a). However, the timing of the row selection signal is performed only in the period (A), and the cycle of the row selection performed according to the scanning timing line (a) is 3τ. In the periods (B) and (C), no row is scanned.

At time t2 in FIG. 21, the scanning timing lines (a), (b), and (c) overlap, but the actual timing of the row selection signal is the scanning timing line (a).
In this case, row selection is performed in the period (A), row selection is performed in the scanning timing line (b) in the period (B), and row selection is performed in the scanning timing line (c) in the period (C). The cycle of row selection performed according to each scanning timing line is 3τ.

Next, FIG. 22 shows an example of output light by the multi-tone exposure method shown in FIG. In this case, Tab: Tbc:
Tca = (3/7) nτ: (6/7) nτ: (12/7) nτ (= 1:
2: 4), it is possible to perform exposure with 2 ³ = 8 gradations.

First, an example of the first row will be described. When the gradation is [0], all the write data by the image data write scan timing lines (a), (b) and (c) are
Set to FF. As a result, all the output lights are turned off, and the exposure time to the photosensitive material becomes zero. At gradation [5],
Image data writing scan timing lines (a), (b),
The write data according to (c) is turned ON, OFF, and ON, respectively. As a result, the output light is ON for the time of Tab + Tca,
The exposure time to the photosensitive material is (15/7) nτ. Gradation [7]
In the case of, the image data write scan timing line
Turn on all the write data according to (a), (b) and (c). As a result, the output light is ON for the time of Tab + Tba + Tca, and the exposure time to the photosensitive material is 3nτ.

In this way, it is possible to perform multi-tone exposure in which the gradation level is proportional to the exposure time on the photosensitive material. Also, on the n-th row, similarly to the first row, multi-tone exposure in which the exposure time on the photosensitive material is proportional to the tone level can be performed.

As described above, according to this method, the exposure period To of eight gradations is 6nτ, and exposure can be performed at a higher speed than the exposure period 8nτ of the above-described conventional method.

According to this multi-tone exposure method, the effect of high-speed exposure becomes more pronounced as the number of gradations increases. Hereinafter, this point will be described in detail. Now, assume that the number of gradations is 2 ^g . At this time, according to this method, the number of scanning timing lines for writing image data is g, and the interval ratio between the scanning timing lines is 1: 2: 4:...: 2 ^(g-1) {g is a positive integer} Becomes The cycle of row selection performed according to each scanning timing line is gτ. Therefore, the exposure period To when the number of gradations is 2 ^g is as follows.

To = 2gnτ [sec] In the above example, the number of tones is set to 2 ^g (g is a positive integer). However, any other number of tones works effectively. Assuming that the number of gradations is h, the number of image data writing scan timing lines is g (g is the smallest integer satisfying 2 ^g ≧ h), and the exposure period To is calculated by 2gnτ.

In the above-described multi-tone exposure method, the interval (Tab: Tbc:...) Between the scanning timing lines is
It is desirable to set exactly a geometric progression of 2 (1: 2:...: 2 ^(g-1) ). Specifically, (Tab: Tbc:...) = (1: 2:. ……:
It is desirable that ^{2 (g-1)) gnτ} / (2 g -1). Also, (Tab: Tbc: .........)
Needs to be an integral multiple of the fundamental period gτ for performing row selection by time division on a plurality (g) of scanning timing lines, and therefore, n = k (2 ^g −1) {k is a positive integer} Desirably. However, actually n = k (2 ^g
-1) There is a row number n that is not {k is a positive integer}. As one of the solutions in this case, assuming that the actual number of rows of the element is n ′, n = k (2 ^g −1) ｛k is a positive integer｝ ≧ n ′, the minimum value of n. Is the virtual number of lines, and the interval (Tab: Tbc:...) Of each scanning timing line is (Tab: Tbc:...) = (1: 2:...):
Set to ^{2 (g-1)) gnτ} / (2 g -1). In this way, the actual number of element rows n ′
In addition, (nn ') rows are left, but the remaining rows may be scanned as dummy rows.

As an example, n ′ = 2000, 2 ^g = 20
When 48 {g = 11}, the virtual row n is set as n = k (2 ^g -1) {k is a positive integer｝ = 2047 {k = 1}. Thus, (Tab: Tbc:...) = (1: 2:...: 2 ^(g-1) ) gnτ / (2 ^g −1) = (1: 2: −−− 1028) gτ And can be set strictly. At this time, (n-
n ′) = 48 rows remain, but they may be scanned as dummy rows.

Further, in this multi-tone exposure method, the interval (Tab: Tbc:...) Of each scanning timing line is strictly set to a geometric progression of 1: 2 (1: 2:...: 2 ^{(g-1)). )} ), The interval may be set so as to have no practical problem. As an example, when n = 2000 and g = 11 scanning timing lines, (Tab: Tbc: ...) = (1: 2: 4 ... 256:
512: 977). Although the last number of the sequence on the right side is not a geometric progression of 2, but the series of the sequence on the right side is 2000, (Tab: Tbc:...) Is an integral multiple of the basic period gτ of row selection. Yes, row selection scanning at set intervals becomes possible. Here, since the last number is 977, 2 ^g (=
From the value of (2048), 47 combinations overlap, and the final number of tones is 2 ^g -47 = 2001. However, if there is no practical problem even in the 2001 gradation, the effect can be sufficiently obtained.

FIG. 23 shows a fourth embodiment of the present invention, that is, FIG.
FIG. 7 is a diagram showing an exposure sequence including correction of a DC component in an embodiment in which the present invention is applied to the multi-tone exposure method described above. In the figure, below the scanning timing line,
The example of the liquid crystal layer voltage Vlc of each row is shown.

This example is basically based on the same concept as in the first embodiment. That is, the exposure sequence cycle is set to T
t, and the exposure sequence period Tt is divided into the periods T1, T
2 and T3. Here, at the beginning of the sequence, the liquid crystal layer voltages Vlc of all the pixels are -Vlcs (OFF).

The period T1 is a period during which the photosensitive material is exposed to light, and is referred to as an exposure period To. In the first half of the period T1, writing and exposure of multi-gradation image data are performed according to a plurality of scanning timing lines (thin solid lines). At this time, in the pixels in the first row, the liquid crystal layer voltage Vlc when the output light OFF is written is −Vlcs, and the liquid crystal layer voltage Vlc when the output light ON is written is + Vlcs.
It is. Further, in the pixels in the n-th row, since no image data is written, the liquid crystal layer voltage Vlc is the initial value -Vlcs.

In the latter half of the period T1, OFF is sequentially written to all the rows according to the scanning timing line (thick broken line). At this time, the liquid crystal layer voltages Vlc of the pixels in the first row are all -Vlcs. In the pixels on the n-th row, the output light O
In the case of FF, the liquid crystal layer voltage Vlc is −Vlcs, and the output light O
When N, the liquid crystal layer voltage Vlc is + Vlcs. As described above, in the exposure period To, the liquid crystal layer voltage Vlc differs depending on the row and the gradation, and the DC component may remain.

The period T2 and the period T3 are the DC voltage removal period T
c, that is, a period in which a voltage for canceling the DC component of the liquid crystal layer voltage Vlc during the exposure period To is applied. First, period T2
The inverted data of the image data written in the period T1 is written in accordance with the scanning timing line (thin broken line) in the first half of the period.

Next, in the latter half of the period T2, ON is sequentially written to all rows in accordance with the scanning timing line (thick solid line). Further, in the first half of the period T3, ON is sequentially written to all rows in accordance with the scanning timing line (thick solid line). Next, in the latter half of the period T3, OFF is sequentially written to all rows in accordance with the scanning timing line (thick broken line). As a result,
In the exposure sequence cycle Tt (= T1 + T2 + T3), the liquid crystal layer voltage Vlc is applied to each row regardless of the gradation.
Is zero, and the remaining DC component is removed.

In the fourth embodiment, as in the case of the first embodiment shown in FIG. 12, the time efficiency of the system can be improved by assigning the DC voltage removal period Tc to the photosensitive material transport period. . Further, as in the third embodiment, an AC voltage may be applied in the DC component correction period Tc.

<Fifth Embodiment> Next, a description will be given of a fifth embodiment in which the present invention is applied to a multi-tone exposure system different from the above. FIG. 24 is a diagram showing an exposure sequence including correction of a DC component in the fifth embodiment. In the figure,
Below the scan timing line, the liquid crystal layer voltage Vlc of each row
Is shown.

In this example, as in the fourth embodiment, 1:
Exposure of eight gradations is performed by a plurality of scanning timing lines at time intervals different from 2: 4. Here, the exposure sequence cycle is Tt, and this exposure sequence cycle Tt is divided into periods T1 and T2.

The period T1 is a period during which the photosensitive material is exposed, and is defined as an exposure period To. In the period T1, (a), (b),
(c) [Thin solid lines] are scanning timing lines for writing image data, and their intervals are different from 1: 2: 4. Further, (a '), (b'), and (c ') [thin broken lines] are scanning timing lines for writing inverted data of image data. Here, (a ') is provided between (a) and (b), (b') is provided between (b) and (c), and (c ') is
It is provided between (c) and the scanning timing line [thick broken line] for writing the state maintenance. The state maintenance write scan timing line [thick broken line] starts from the latter half of the period T1. In this case, since six scanning timings are multiplexed, these are selected by time division. Therefore, the time of the period T1 is 6nτ × 2 = 12nτ.

The specific applied liquid crystal layer voltages in the above three types of scanning timing lines are as shown in FIG.
Is written according to the upper part of the figure, and ON is written according to the lower part of the figure.) According to such a method, as can be seen from the liquid crystal layer voltages in FIG. 14, after + Vlcs is applied by ON writing, -Vlcs having a polarity opposite to that of + Vlcs is always applied.
Vlcs is applied for the same time. The voltage is always zero V during OFF writing and state maintaining writing.
As a result, in the period T1, the average value of the liquid crystal layer voltage Vlc becomes zero in each row irrespective of the gradation, and the above-mentioned remaining DC component is removed.

Unlike the above-described embodiment, the removal of the DC component is not necessarily required in the period T2, but it is necessary to wait as the photosensitive material transport time Tc, and an appropriate voltage is applied using this. be able to. The example of FIG. 24 is a case where nothing is changed from the last state of the period T1. In this case, there is no problem in the period T2 because all the pixels are OFF and the liquid crystal layer voltage Vlc is also zero V. Further, an AC voltage may be applied during this period.

The embodiments of the present invention are not limited to the above-described first to fifth embodiments, and various changes can be made in the scanning timing, the writing mode, the liquid crystal layer voltage, and the like. .

For example, in the first embodiment, the circuit for maintaining the light modulation state of the pixel portion is an n-MOS-FET and a storage capacitor C.
Although the storage capacity is constituted by stg, this storage capacity can be omitted if there is no operational problem even without the storage capacity Cstg.

FIG. 1 shows a state where the light modulation state of the pixel portion is maintained.
Is composed of a single crystal semiconductor, but may be composed of a polycrystalline semiconductor as shown in FIG. The pixel section circuit of FIG. 25 is formed by forming a MOS-FET of a pixel on a glass substrate 50 by a poly-Si TFT process. In the figure, 51 is a gate insulating film, 52 is an interlayer insulating film,
53 is a pixel electrode (Al), 54 is a source electrode, 55 is a gate electrode, and 56 is a drain electrode.

As in the example shown in FIG. 26, the pixel section circuit may be made of an amorphous semiconductor. In the pixel section circuit of FIG. 26, a MOS-FET of a pixel is mounted on a glass substrate 60.
It is formed by an a-Si TFT process. In the figure, 61 is a gate insulating film (SiNx), 62 is an interlayer insulating film, 63 is a pixel electrode (Al), 64 is a source electrode, 65 is a gate electrode, 66 is a drain electrode, and 67 is a channel protective film (SiNx). ).

Further, a composite structure in which the peripheral driving circuit is formed of a single crystal semiconductor and the pixel portion is formed of a polycrystalline semiconductor or an amorphous semiconductor may be employed.

Further, the circuit for maintaining the light modulation state of the pixel portion may be constituted by a binary memory circuit such as an SRAM circuit as shown in FIG. In the example of FIG. 27,
When data of 1 or 0 is supplied from the data signals Vd and / Vd and a pulse for enabling data writing to the SRAM is given to the row selection signal / WE at the same time, S
Data of 1 or 0 is written to the RAM, and the output voltage V
s is retained. The liquid crystal performs light modulation according to the written data, and this state is maintained until the data of the SRAM is newly updated.

Further, if it is suitable for the purpose of the present invention,
Any other pixel circuit may be used.

[Brief description of the drawings]

FIG. 1 is a sectional view of a pixel portion of a spatial light modulator that can be used in the present invention.

FIG. 2 is an equivalent circuit diagram of a pixel portion of the spatial light modulator.

FIG. 3 is a schematic view showing a light modulation optical system using the spatial light modulation element.

FIG. 4 is an explanatory diagram showing a relationship between a liquid crystal layer voltage and a liquid crystal alignment position.

FIG. 5 is a graph showing each voltage of the pixel unit and an output light waveform.

FIG. 6 is an equivalent circuit diagram of a two-dimensional matrix type spatial light modulator.

FIG. 7 is a schematic view showing a driving method of a two-dimensional matrix type spatial light modulator.

FIG. 8 is a schematic diagram of an exposure system using a spatial light modulator.

FIG. 9 is a schematic view showing an exposure sequence on a photosensitive material applicable to the present invention.

FIG. 10 is a schematic diagram showing a row selection signal timing and a scanning timing line in the first embodiment of the present invention.

FIG. 11 is a schematic view showing an exposure sequence in the first embodiment.

FIG. 12 is a schematic diagram illustrating the relationship between the DC component correction timing and the exposure system drive timing in the first embodiment.

FIG. 13 is a schematic diagram showing characteristics (response of liquid crystal layer voltage and output light) of a ferroelectric liquid crystal used in a second embodiment of the present invention.

FIG. 14 is an explanatory diagram showing a relationship between a type of writing and an applied liquid crystal layer voltage in the second embodiment.

FIG. 15 is a schematic view showing an exposure sequence in the second embodiment.

FIG. 16 is a schematic diagram showing the relationship between the drive timing of a spatial light modulator and the drive timing of an exposure system according to a third embodiment of the present invention.

FIG. 17 is an explanatory diagram showing an example of an AC voltage waveform applied to a liquid crystal layer.

FIG. 18 is an explanatory diagram showing another example of an AC voltage waveform applied to the liquid crystal layer.

FIG. 19 is a timing chart of a write scan in the fourth embodiment of the present invention.

FIG. 20 is a schematic diagram showing a row selection signal timing and a scanning timing line at one time in FIG. 19;

FIG. 21 is a schematic diagram showing a row selection signal timing and a scanning timing line at another time in FIG. 19;

FIG. 22 is a schematic diagram showing a modulation state of output light in the fourth embodiment.

FIG. 23 is a schematic view showing an exposure sequence in the fourth embodiment.

FIG. 24 is a schematic view showing an exposure sequence according to a fifth embodiment of the present invention.

FIG. 25 is a cross-sectional view of a pixel portion formed of a polycrystalline semiconductor.

FIG. 26 is a cross-sectional view of a pixel portion formed of an amorphous semiconductor.

FIG. 27 is a cross-sectional view of a pixel portion including an SRAM circuit.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 two-dimensional matrix type spatial light modulator 2 PBS 3 light source 4 condenser lens 5 shutter 6 projection lens 7 photosensitive material 8 image signal generator 10 p ^- type silicon semiconductor substrate 11 n-MOS-FET 12 charge storage capacitor 13 drain region 14 source region 15 gate oxide film 16 gate electrode 17 p ⁺ region 18 oxide film 19 poly-Si film 20 first interlayer insulating film 21 first layer Al wiring 22 source electrode 23 drain electrode 24 second interlayer insulating film 25 pixel electrode ( Second layer Al) 26 Alignment film 27 Opposing transparent substrate 28 Opposing transparent common electrode 29 Alignment film 50 Glass substrate 51 Gate insulating film 52 Interlayer insulating film 53 Pixel electrode (Al) 54 Source electrode 55 Gate electrode 56 Drain electrode 60 Glass substrate 61 Gate insulating film (SiNx) 62 Interlayer insulating film 63 Pixel electrode (Al) 64 Source electrode 65 Gate electrode 66 Drain electrode 67 Channel protective film (SiNx)

Claims (17)

[Claims] 1. A spatial light modulation device comprising: a pixel section whose light modulation state changes according to an applied voltage; and a circuit for updating and maintaining a light modulation state of each pixel section, the pixel section being arranged in a two-dimensional matrix. An image exposure using a two-dimensional matrix type spatial light modulator, which is arranged on an optical path of exposure light, and irradiates the photosensitive material with the exposure light modulated for each pixel unit by the spatial light modulator to expose the photosensitive material. An image exposure method using a two-dimensional matrix type spatial light modulator, wherein a DC voltage having a polarity opposite to the DC voltage is applied to each of the pixel units. 2. The method according to claim 1, wherein the DC voltage of the opposite polarity has an absolute value substantially equal to the DC voltage for the exposure light modulation, and is applied for a time substantially equal to the application time of the DC voltage for the exposure light modulation. 2. An image exposure method using the two-dimensional matrix type spatial light modulator according to claim 1. 3. When the pixel section is set to an ON state for outputting exposure light for a predetermined time, an absolute value of the applied DC voltage for setting the ON state is substantially equal to that of the pixel section during a period other than the ON state, and the pixel section has an opposite polarity. Is applied to the pixel unit for a time substantially equal to the ON state setting time, and when the pixel unit is set to the OFF state in which the exposure light is not output for a predetermined time, the OFF state is applied during periods other than the OFF state.
3. The method according to claim 1, wherein a DC voltage having an absolute value substantially equal to the applied DC voltage for setting the state and having the opposite polarity is applied to the pixel portion for a time substantially equal to the OFF state setting time. An image exposure method using a dimensional matrix type spatial light modulator. 4. When the pixel section is set to an ON state for outputting exposure light for a predetermined time, during a period other than the ON state, the applied DC voltage for setting the ON state is substantially equal to the absolute value, and has an opposite polarity. Is applied to the pixel portion for a time substantially equal to the ON state setting time, and when the pixel portion is set to the OFF state in which the exposure light is not output for a predetermined time, almost 0 V is applied during a period other than the OFF state. 2. The method according to claim 1, wherein the voltage is applied to the pixel unit for a predetermined time.
Or an image exposure method using the two-dimensional matrix type spatial light modulator according to 2. 5. The method according to claim 1, wherein the step of applying a DC voltage having a polarity opposite to that of the DC voltage includes a step of always applying substantially 0 V regardless of the ON state and the OFF state of the pixel unit. An image exposure method using the two-dimensional matrix type spatial light modulator according to any one of the preceding claims. 6. The shutter according to claim 1, further comprising a shutter capable of opening and closing an optical path of the exposure light to the photosensitive material, and closing the shutter during a period in which the reverse polarity DC voltage is applied. An image exposure method using the two-dimensional matrix type spatial light modulator according to claim 1. 7. A spatial light modulation element comprising a pixel section whose light modulation state changes according to an applied voltage is arranged in a two-dimensional matrix, and a circuit for updating and maintaining the light modulation state of each pixel section. Image exposure using a two-dimensional matrix-type spatial light modulation element, which is arranged on an optical path of exposure light, and irradiates the photosensitive material with exposure light modulated for each pixel unit by the spatial light modulation element to expose the photosensitive material. In the method, a two-dimensional matrix-type spatial light modulator is used, in which, for each of the pixel units, an AC voltage is applied outside the exposure period after applying a DC voltage and modulating the exposure light. Image exposure method. 8. A shutter for opening and closing an optical path of the exposure light to the photosensitive material, and a period for applying the AC voltage,
8. The method according to claim 7, wherein the shutter is closed.
An image exposure method using the two-dimensional matrix type spatial light modulator according to the above. 9. The two-dimensional matrix type space according to claim 1, wherein the pixel portion whose light modulation state changes according to the applied voltage is made of a ferroelectric liquid crystal. An image exposure method using a light modulation element. 10. The image exposure method using a two-dimensional matrix type spatial light modulator according to claim 9, wherein the ferroelectric liquid crystal has a memory property in at least one alignment direction. 11. The circuit according to claim 1, wherein the circuit for updating and maintaining the light modulation state is configured by an element including a single crystal semiconductor.
An image exposure method using a dimensional matrix type spatial light modulator. 12. The method according to claim 1, wherein the circuit for updating and maintaining the light modulation state is configured by an element including a polycrystalline semiconductor.
An image exposure method using a dimensional matrix type spatial light modulator. 13. The device according to claim 1, wherein the circuit for updating and maintaining the light modulation state is configured by an element including an amorphous semiconductor.
An image exposure method using a dimensional matrix type spatial light modulator. 14. The photosensitive material according to claim 1, wherein the photosensitive material is irradiated with exposure light whose irradiation time is controlled for each pixel portion of the spatial light modulator, and the photosensitive material is exposed in multiple gradations.
3. An image exposure method using the two-dimensional matrix type spatial light modulator according to any one of 3. 15. A method for selectively scanning all rows of the spatial light modulator at a plurality of different time intervals, applying a DC voltage to each pixel unit in the selected row based on image data, 9. The method according to claim 8, wherein the selected scans performed at different time intervals are temporally multiplexed, and one selected row is determined by time division from the plurality of different rows that have received the multiplexed scan. 15. An image exposure method using the two-dimensional matrix type spatial light modulator according to 14. 16. The method according to claim 15, wherein the plurality of time intervals is a geometric progression of 2: 1: 2:...: 2 ^(g-1) {g is a positive integer}. An image exposure method using a two-dimensional matrix type spatial light modulator. 17. The two-dimensional matrix type space according to claim 15, wherein when the time of the row selection is τ and the number of intervals is g, the row selection is performed at a basic period gτ. An image exposure method using a light modulation element.