JP2839982B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus provided with an image reading section comprising a liquid crystal light valve of a light address type.

[0002]

2. Description of the Related Art In recent years, with the advancement of advanced information, image copying apparatuses that can easily copy originals have become widespread in offices.
Furthermore, it is spreading to general households.

FIG. 14 is a schematic configuration diagram showing the configuration of an image reading section of a conventional image copying apparatus.

As shown in FIG. 1, an image reading section of the conventional image copying apparatus includes a light source 201 composed of a fluorescent lamp, a halogen lamp or the like, a first mirror 202, a second mirror 203,
The scanning optical system 210 includes a third mirror 204, a lens 205, and a fourth mirror 206.

The light source 201, the first mirror 202, the second mirror 203, and the third mirror 204 are moved in parallel along the surface of the document 212 by a driving device (not shown) (bidirectional arrows shown in the drawing). ).

The scanning optical system 210 is configured to guide the light reflected by the original 212 to the photosensitive drum 211 when the light from the light source 201 is irradiated.

In such a configuration, the original 212 is
Illuminated by light from 201 and reflected from original 212
Reference numeral 207 denotes a first mirror 202 along the alternate long and short dash line shown in FIG.
It is guided to the photosensitive drum 211 via the second mirror 203, the third mirror 204, the lens 205, and the fourth mirror 206,
An electrostatic latent image is formed on the surface of the photosensitive drum 211. This electrostatic latent image is visualized as a toner image by toner, and is then transferred onto paper to form a copy image.

Further, after converting the reflected light from the original into an electric signal and processing it by an image processing circuit, an electrostatic latent image is formed on the photoreceptor by, for example, outputting a laser to expose the photoreceptor. Some image copying apparatuses are configured as described above.

FIG. 15 is a block diagram showing a circuit included in a conventional image copying apparatus for converting reflected light from a document into an electric signal and sending it to an image processing circuit.

As shown in FIG. 1, a scanning optical system having a configuration similar to that of the scanning optical system 210 shown in FIG. The image is guided to the conversion unit 221 and is imaged.
The photoelectric conversion unit 221 outputs an analog electric signal to an A / D (analog / digital) converter 222, and the A / D converter 222 converts the analog electric signal into a digital signal. The converted digital signal is stored in the image memory 223, and thereafter, is converted by the image processing circuit 224 into the image memory 22.
The digital signal is read from 3 and the necessary processing for copying is performed.

[0011]

Among such conventional image copying apparatuses, an image copying apparatus shown in FIG. 14 forms a copied image by forming reflected light corresponding to a document image on a photosensitive drum. Since it is formed, an optical system for scanning a document is required, and there is a problem that the apparatus itself becomes complicated and large.

Also, the reflected light from the original as shown in FIG. 15 is converted into an electric signal, processed by an image processing circuit, and then the laser is output to expose the photoreceptor. In an image copying apparatus configured to form a latent image, when converting reflected light corresponding to a document image into a digital image signal, the optical signal is first converted into an electric signal, and then converted into an optical signal again. It must be corrected, and a mechanism for that is necessary, and there is a problem that the device itself becomes complicated and large.

Accordingly, the present invention provides a compact and high-performance image forming apparatus that combines an image reading function and an image display function in an image reading section.

[0014]

An image reading function for reading an image of an original is provided with a liquid crystal light valve.
An image forming apparatus comprising an image reading unit, an image forming unit having a photosensitive drum and an image display function for displaying the image of the document, the liquid crystal of the image reading unit write-back
Lube includes two substrates each having an electrode, and a liquid crystal layer provided between two substrates, the two substrates one
A photoconductor layer provided on one of the substrates, the impedance of which changes due to light containing incident information;
A dielectric mirror that covers the photoconductor layer
An optical waveguide provided on the other substrate , a light source for introducing light into the optical waveguide, and a light receiving unit for receiving light from the light source propagating through the optical waveguide and converting the light into an electric signal are provided.
The image forming unit has an image reading function of the image reading unit.
Based on the image data of the original read by
Forming an image by exposing the drum, or
Is the image reading unit by the image display function of the image reading unit
Irradiates readout light on the image displayed on the other substrate side
The photoreceptor by the light reflected by the dielectric mirror
Image formation that forms an image by exposing a drum
The object is solved by a device .

[0015]

When a voltage is applied between the electrodes provided on the two substrates of the liquid crystal light valve in the absence of address light (dark state), the impedance of the photoconductor layer is larger than the impedance of the liquid crystal layer. The voltage is hardly applied to the liquid crystal in the liquid crystal layer, and the alignment state of the liquid crystal does not change. In this state, when viewed from the polarization direction of light propagating through the optical waveguide, the refractive index of the liquid crystal is set smaller than the refractive index of the optical waveguide, so that the light from the light source can propagate through the optical waveguide, An optical signal can be received by the light receiving means. Further, when a voltage is sequentially applied between the electrodes provided on the two substrates in a state where the address light is incident on the liquid crystal light valve (bright state), the impedance of the photoconductor layer becomes low in the bright state, Since a voltage is applied to the liquid crystal, the alignment state of the liquid crystal changes, and the impedance of the photoconductor layer does not change in the dark state, so that the alignment state of the liquid crystal does not change. At this time, in the part where the orientation of the liquid crystal near the optical waveguide changes, the refractive index of the liquid crystal becomes larger than the refractive index of the optical waveguide when viewed from the polarization direction of the light propagating in the optical waveguide. During the propagation through the optical waveguide, the liquid crystal leaks in the liquid crystal direction at the portion where the orientation of the liquid crystal has changed, and the intensity of the optical signal received by the light receiving means changes. Therefore, information corresponding to the address light can be obtained electrically by synchronizing the scanning of the electrode with the electric signal output from the light receiving means. As described above, information formed in the liquid crystal layer corresponding to the address light can be read as an optical signal and directly as an electric signal. Also, the photosensitive drum is exposed based on the electric signal.
Or the optical waveguide of this liquid crystal light valve
Light is irradiated from the substrate side on which the
The photosensitive drum with light reflected by
Can also.

In the image forming apparatus according to the present invention, since such a liquid crystal light valve is used as an image reading unit, an optical system for scanning a document is not required.
Thus, high-performance image-shaped compact that combines the image reading function and an image display function in the image reading unit
The deposition apparatus can be realized.

[0017]

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

FIG. 2 is a sectional view showing the structure of a first embodiment of the liquid crystal light valve constituting the image reading section of the image forming apparatus according to the present invention.

As shown in FIG. 1, the liquid crystal light valve 10 of this embodiment comprises glass substrates 11 and 12, an antireflection film 13, a transparent electrode 14, a counter electrode 15, an optical waveguide 16, a photoconductor layer 17, It includes a layer 18, alignment films 19 and 20, a spacer 21, a liquid crystal layer 22, and a dielectric mirror 23.

The liquid crystal light valve 10 is manufactured as follows.

First, a transparent conductive film of tin dioxide (SnO ₂ ) is deposited on a glass substrate 11 which is a light-transmitting substrate by a sputtering method, and is patterned into a stripe shape through a photolithographic process. Transparent transparent electrode 14
To form

Next, an amorphous silicon hydride (a-Si: H) film is formed as a photoconductor layer 17 on the transparent electrode 14. The a-Si: H film forming the photoconductor layer 17 is made of silane (S
An iH ₄ ) gas and a hydrogen (H ₂ ) gas are used as raw materials and formed by a plasma CVD (chemical vapor deposition) method. This a
The thickness of the -Si: H film is about 6 µm.

Next, a carbon-dispersed acrylic resin is spin-coated on the photoconductor layer 17 as a light-shielding layer 18 for blocking light incident on the photoconductor layer 17 from the side of the liquid crystal layer described later. . Thereafter, a multilayer made of titanium oxide (TiO ₂ ) and silicon oxide (SiO ₂ ) is provided on the light shielding layer 18 as a dielectric mirror 23 for reflecting light incident on the photoconductor layer 17 from the liquid crystal layer side. The film is formed by an electron beam (EB) evaporation method.

On the side of the glass substrate 11 on which the writing light 24 is incident, an anti-reflection film 13 for preventing surface reflection of the glass is formed.

As the above-mentioned light-transmitting substrate, a fiber plate can be used in addition to the glass substrate.

On the glass substrate 12 facing the glass substrate 11, a transparent conductive film made of tin-doped indium oxide (ITO) is deposited by a sputtering method.
The counter electrode 15 is formed.

Next, a polymer thin film is selectively polymerized on the counter electrode 15 to form an optical waveguide in a stripe shape.
Form 16.

Next, after polyimide films are formed as the alignment films 19 and 20 by spin coating on the light shielding layer 18 and the optical waveguide 16, respectively, the surfaces of the alignment films 19 and 20 are subjected to a molecular alignment treatment by rubbing.

The glass substrates 11 and 12 on which the respective layers and films are formed as described above are bonded together via a spacer 21 also serving as a seal, and a liquid crystal layer 22 is provided between the substrates.
Vacuum injection of nematic liquid crystal with positive relative dielectric constant as
The liquid crystal light valve 10 is configured by sealing.

The orientation of the liquid crystal molecules, when viewed from the polarization direction of light propagating through the optical waveguide 16, is such that the refractive index of the liquid crystal becomes larger than the refractive index of the optical waveguide when a voltage is applied to the liquid crystal. Is set so that it becomes smaller when no voltage is applied.

The twist angle of the liquid crystal is 0 ° to 60 °, preferably 45 °. The tilt angle is preferably in the range of 0.05 ° to 30 °.

The material of the liquid crystal contained in the liquid crystal layer 22 includes:
For example, Merck ZLI-4389 (n _e (the refractive index of the liquid crystal molecular axis direction) = 1.66, n _o (refractive index) = 1.50 in the direction perpendicular to the liquid crystal molecular axis) used. The thickness of the liquid crystal layer 22 is about 4
μm. A small amount of cholesteric liquid crystal was added to this liquid crystal as needed.

Since the liquid crystal molecules are aligned on the optical waveguide 16 by the rubbing process, the configuration may be such that the alignment film 20 is not provided if necessary.

In FIG. 2, a photodetector and a light source, which will be described later, are omitted for simplification.

Next, the glass substrate 12, counter electrode 15,
The configuration of the counter substrate 25 including the optical waveguide 16 and the alignment film 20 will be described.

FIG. 3 is a plan view showing the structure of the counter substrate 25 included in the liquid crystal light valve 10 of FIG. 2 which constitutes the image reading section of the image forming apparatus according to the present invention. FIG.
3 is a sectional view of FIG. 3, FIG. 4A is a sectional view taken along line AA of FIG. 3, and FIG. 4B is a sectional view taken along line BB of FIG. In these figures, the alignment film 20 is omitted.

As shown in these figures, the opposing substrate 25 comprises a glass substrate 12, an opposing electrode 15, an optical waveguide 16 comprising a lower cladding layer 26, a core layer 27 and a cladding layer 28, a photodetector 29, and a light source 30. And

The counter substrate 25 is manufactured as follows.

First, a transparent conductive film made of ITO is formed on the entire surface of a glass substrate 12 to form a counter electrode 15.

Next, as the lower cladding layer 26 of the optical waveguide 16, an epoxy resin is formed by spin coating. On the lower cladding layer 26, a bisphenol-Z-polycarbonate (PCZ) film containing a photopolymerizable monomer (acrylate, for example, methyl acrylate) is spin-coated. Here, by irradiating ultraviolet rays through a striped photomask and selectively polymerizing, a PCZ layer as a core layer 27 and PCZ and PCZ as cladding layers 28 are formed.
A mixture with a polyacrylate having a lower refractive index than Z is formed so as to form a stripe shape with each other. In this embodiment, the refractive index n of the core layer 27 is 1.59, and the refractive index n of the cladding layer 28 is 1.56.

The lower clad layer thus formed
A light source 30 and a photodetector 29 are connected to both ends of the optical waveguide 16 composed of the core layer 27 and the cladding layer 28, respectively.

The light source 30 is composed of, for example, a laser and a light emitting diode (LED), and is connected to the optical waveguide 16 so that a polarized wave (TE mode or TM mode) can be introduced into the optical waveguide 16. I have.

The photodetector 29 is, for example, an a-Si: H diode and an a-SiGe:
It is composed of an H diode or the like, and is connected to the optical waveguide 16 so that light from the optical waveguide 16 can be received.

FIG. 5 is a sectional view taken along the line BB of FIG. 3 for explaining another structure of the counter substrate 25. As shown in FIG.

In the embodiment shown in FIG.
Was formed on the entire surface of the glass substrate 12, as shown in FIG. 5, the counter electrode 15 was formed in a stripe shape on the glass substrate 12, and the lower cladding layer 26, the core layer 27, and the cladding layer were formed on the counter electrode 15. The optical waveguide consisting of 28 may be formed in a stripe shape. In this case, the counter electrode and the scanning electrode are arranged so as to be orthogonal to each other.

The opposing substrate is not limited to a transparent substrate, but may be single crystal silicon (Si) or single crystal gallium arsenide (GaAs).
A substrate can be used, and in the case of using these, a light source and a photodetector can be formed on the substrate.

Glass substrates 11 and 12 are one embodiment of the two substrates of the present invention. The optical waveguide 16 is one embodiment of the optical waveguide of the present invention. The photoconductor layer 17 is an embodiment of the photoconductor layer of the present invention. The liquid crystal layer 22 is an embodiment of the liquid crystal layer of the present invention. The photo detector 29 is an embodiment of the light receiving means of the present invention. Light source 30 is an embodiment of the light source of the present invention.

Next, the operation of the liquid crystal light valve 10 having the above configuration will be described.

FIG. 6 is a conceptual diagram of liquid crystal molecules for explaining the refractive index of the liquid crystal molecules.

[0050] As shown in the figure, the refractive index of the liquid crystal molecules 31, the anisotropy and the refractive index n _e of the liquid crystal molecular axis direction X, the refractive index n _o of the direction Y perpendicular to the liquid crystal molecular axis direction X And n
the relationship of _e> n _o holds. Here, the refractive index n _w of the core layer of the optical waveguide, the refractive index n _e and n _o of the liquid crystal molecules,
The relationship between these is set to be a _{n e> n w> n o} .

With this setting, the light propagating in the optical waveguide undergoes a change in light intensity in accordance with the alignment state of the liquid crystal molecules. That is, when the n _w> n _o, the light propagating through the optical waveguide for leaking to the liquid crystal layer, it is possible to propagate unattenuated. On the other hand, when the n _e> n _w, light propagating through the optical waveguide for leaking the liquid crystal layer, decays.

FIG. 7 is a schematic diagram showing the alignment state of liquid crystal molecules when light in the TM mode propagates through the optical waveguide 16. FIG. 7A is a schematic view showing a cross section of a main part of the liquid crystal light valve 10, and FIG. 7B is a schematic view of the liquid crystal light valve 10 shown in FIG.
Is a schematic diagram when viewed from above (in the direction of arrow C).

In these figures, the glass substrate 12 and the optical waveguide 16 are schematically shown, and the counter electrode 15 and the like are omitted.

[0054] The refractive index of these as shown in FIG., The liquid crystal molecules 31a in a state in which the voltage to light 36 is not applied in the TM mode from the light source 30 shown in FIGS. 3 and 4 is approximately n _o
Becomes On the other hand, the refractive index of the liquid crystal molecules 31b in a state where the voltage is applied, it can be regarded as substantially n _e.

FIG. 8 is a schematic diagram showing an operation state of the liquid crystal light valve 10 when no drive voltage is applied. 8A shows a case where address light is not incident on the liquid crystal light valve 10 (dark state), and FIG. 8B shows a case where address light is incident on the liquid crystal light valve 10 (bright state). The operating state of the light valve 10 is shown.

In these figures, the same components as those of the liquid crystal light valve 10 shown in FIG. 2 are denoted by the same reference numerals as those in FIG. However, for the points that do not affect the description here, for example, the antireflection film 13 and the dielectric mirror 23 in FIG. 2 are omitted and the shape of the transparent electrode 14 is simplified.

As shown in these figures, when the driving voltage from the AC power supply 35 is not applied between the transparent electrode 14 and the counter electrode 15 of the liquid crystal light valve 10, the optical waveguide
16 shows TM mode light 36 from the light source 30 shown in FIGS.
When the light is propagating, the liquid crystal layer is exposed to the TM mode light 36 regardless of the presence or absence of the address light 37, that is, regardless of the brightness state.
The refractive index of 22, to become substantially n _o, the propagating light is not attenuated, propagating through the optical waveguide 16.

FIG. 9 is a schematic diagram showing an operation state of the liquid crystal light valve 10 in a state where a driving voltage is applied. FIG. 9A shows the liquid crystal when the address light is not incident on the liquid crystal light valve 10 (dark state), and FIG. 9B shows the liquid crystal when the address light is incident on the liquid crystal light valve 10 (bright state). The operating state of the light valve 10 is shown.

In these figures, the same components as those of the liquid crystal light valve 10 shown in FIG. 2 are denoted by the same reference numerals as those in FIG. However, for the points that do not affect the description here, for example, the antireflection film 13 and the dielectric mirror 23 in FIG. 2 are omitted and the shape of the transparent electrode 14 is simplified.

As shown in FIG. 9A, a liquid crystal light valve
In the state where a driving voltage is applied between the transparent electrode 14 and the counter electrode 15 by the AC power supply 35, when the TM mode light 36 propagates through the optical waveguide 16, When the light is not incident on the liquid crystal light valve 10 (in a dark state), almost no voltage is applied to the liquid crystal layer 22 because the impedance of the photoconductor layer 17 is high.
No change occurs in the orientation state of a. In this case, the optical waveguide 16
In the light 36 of the TM mode propagates, the refractive index of the liquid crystal layer 22 to light 36 in TM mode, to become substantially n _o, the propagating light is not attenuated, propagates through the optical waveguide 16.

On the other hand, as shown in FIG. 9B, when the address light 37 is incident on the liquid crystal light valve 10 from above (in a bright state), the impedance of the photoconductor layer 17 is low. Voltage is applied to the liquid crystal layer 22, and the liquid crystal molecules
The orientation state of 32b changes. In this case, when the TM mode light 36 from the light source 30 shown in FIGS. 3 and 4 propagates through the optical waveguide 16, the refractive index of the liquid crystal layer 22 becomes almost _ne with respect to the TM mode light 36. The propagating light is attenuated in the area where the voltage is applied (the area where the transparent electrode 14 extends), and the light propagating in the optical waveguide 16 is weakened.

As a result, when the light intensity is detected at the end of the optical waveguide 16 by the photodetector 29 shown in FIGS. 3 and 4, an electric signal corresponding to the alignment state of the liquid crystal is obtained. Further, when viewed from the polarization direction of the light propagating through the optical waveguide 16, the refractive index of the liquid crystal increases as the applied voltage increases, so that the gradation data can be extracted as an electric signal.

On the contrary, when the voltage is not applied to the liquid crystal, the refractive index of the liquid crystal is set to be larger than the refractive index of the optical waveguide 16 when viewed from the polarization direction of the light propagating through the optical waveguide 16. Also, when a voltage is applied to the liquid crystal,
Can be used such that the refractive index of the liquid crystal is smaller than the refractive index of the optical waveguide 16 when viewed from the polarization direction of light propagating through the optical waveguide. In this case, it is preferable to use a nematic liquid crystal in which the relative permittivity of the liquid crystal is negative and set the tilt angle to 60 ° to 90 °.

In the above-mentioned alignment state of the liquid crystal molecules, the optical waveguide
16 when the light 36 in the TE mode is propagated, the refractive index of the liquid crystal layer 22 with or without the application of the driving voltage for the n _o, the light propagates through the optical waveguide 16. In this case, the orientation state is changed.

FIG. 10 is a schematic diagram showing the alignment state of liquid crystal molecules when light in the TE mode propagates through the optical waveguide 16. FIG. 10 (A) is a schematic view showing a main part of the liquid crystal light valve 10, and FIG. 10 (B) is a liquid crystal light valve of FIG. 10 (A).
FIG. 10 is a schematic diagram when 10 is viewed from above (the direction of arrow D).

In these figures, the glass substrate 12 and the optical waveguide 16 are schematically shown, and the counter electrode 15 and the like are omitted.

[0067] The refractive index of these as shown in FIG., The liquid crystal molecules 33a in a state in which the voltage to light 38 is not applied in the TE mode from the light source 30 shown in FIGS. 3 and 4 is approximately n _e
Becomes On the other hand, the refractive index of the liquid crystal molecules 33b in a state where the voltage is applied, it can be regarded as substantially n _o.

As described above, it is necessary to set the alignment state of the liquid crystal molecules according to the light propagation mode in the optical waveguide 16.

Therefore, according to the liquid crystal light valve of the above-described embodiment, the information formed in the liquid crystal layer corresponding to the address light can be read as an optical signal and directly as an electric signal.

Next, a conversion mechanism for converting optical information into an electric signal will be described.

FIG. 11 is a block diagram of an embodiment of a conversion mechanism for converting optical information into an electric signal.

As shown in the figure, the conversion mechanism of this embodiment includes a liquid crystal light valve 40 including a scanning electrode 41, a counter electrode 42, an optical waveguide 43, a light source 44, and a photodetector 45, a reading circuit 46, a signal A processing circuit 47, a drive circuit 48, and a control circuit 49 are provided.

The liquid crystal light valve 40 corresponds to the liquid crystal light valve 10 shown in FIG.
The optical waveguide 43 corresponds to the transparent electrode 14, the counter electrode 15, and the optical waveguide 16, respectively. Further, the light source 44 and the photo detector 45 correspond to the light source 30 and the photo detector 29 shown in FIGS. 3 and 4, respectively.

The control circuit 49 includes a light source 44 and a readout circuit 46.
And the drive circuit 48. Drive circuit
48 is connected to the scanning electrode 41 and the counter electrode 42, respectively. The readout circuit 46 is connected to the photodetector 45 and the signal processing circuit 47, respectively.

The operation of the conversion mechanism will be described.

The polarized light from the light source 44 is always introduced into the optical waveguide 43, and the light propagated through the optical waveguide 43 is converted into an electric signal by using a photodetector 45.
Here, when the light 51 containing information is incident on the liquid crystal light valve 40, a voltage is applied between the counter electrode 42 and the scanning electrode 41 via the drive circuit 48.

Driving by applying the voltage is performed as follows.

When a voltage is applied to only one line of the scanning electrode 41, the alignment state of the liquid crystal molecules corresponding to the position of the scanning electrode 41 changes according to the light / dark state of the light, and the light intensity propagating through each of the optical waveguides 43 is changed. Is modulated. When the output of the photodetector 45 is read by the readout circuit 46 in synchronization with this,
An electric signal of optical information corresponding to the scanning electrode 41 is obtained. When such scanning electrodes 41 are sequentially driven over the entire screen, an electric signal corresponding to two-dimensional optical information can be obtained.

The conversion of an electric signal corresponding to optical information into an optical signal is performed as follows.

The light from the light source 44 is shut off, and a voltage is applied between the counter electrode 42 and the scanning electrode 41 via a drive circuit 48. In this state, when the light 51 containing information enters, the impedance of the photoconductor layer changes according to the light state of the light, so that the alignment state of the liquid crystal changes. Here the reading light 52
And the reflected light modulated by the liquid crystal layer is detected, whereby an optical signal corresponding to optical information can be obtained.

Therefore, according to this embodiment, since the electric signal can be taken out together with the optical signal from the liquid crystal light valve 40, it is possible to realize a compact and high-performance conversion mechanism capable of reading out information.

Next, an embodiment of an image forming apparatus using the liquid crystal light valve 10 of FIG. 2 as an image reading section will be described.

FIG. 1 is a system configuration diagram of an embodiment of the image forming apparatus according to the present invention.

As shown in the figure, the image forming apparatus of this embodiment includes a light source 62, a lens 63, a liquid crystal light valve 64, a laser light emitting device 65, a polygon mirror 66, a mirror 67, a galvano mirror 68, 72, polarizing plate 69, imaging lens 70, photosensitive drum 71, drive control system 73, image memory 74, image processing circuit
75, an interface circuit 76 and a printer control system 77.

The liquid crystal light valve 64 corresponds to the liquid crystal light valve 10 of FIG. 2 and the liquid crystal light valve 40 of FIG. 11, and is connected to the drive control system 73.

The drive control system 73 corresponds to a circuit including a read circuit 46, a signal processing circuit 47, a drive circuit 48, and a control circuit 49 included in the conversion mechanism for converting optical information into an electric signal in FIG. .

Laser emitting device 65, polygon mirror 6
6. The galvanometer mirror 72 and the photosensitive drum 71 are connected to a printer control system 77, respectively.

Light source 62, lens 63 and liquid crystal light valve 64
Is an embodiment of the image reading unit of the present invention. Laser light emitting device 65, polygon mirror 66, mirror 67, galvanometer mirror 72, drive control system 73, image memory 74, image processing circuit 75, interface circuit 76, and printer control system 77
Is an embodiment of the image forming unit of the present invention.

In this apparatus, reading of an image is performed as follows.

The light from the light source 62 is applied to the original 61 so that the original 61
The reflected light from
To form an image.

At this time, when the scan electrodes (the electrodes corresponding to the transparent electrode 14 in FIG. 2 and the scan electrode 41 in FIG. 11) of the liquid crystal light valve 64 are sequentially driven by the drive control system 73, an electric signal corresponding to an image is obtained. The image information data corresponding to the electric signal is stored in the image memory 74, and the image information data can be handled as a digital signal.

Copying of the original 61 is performed using a laser scanning system. That is, the counter electrode (the electrode corresponding to the counter electrode 15 in FIG. 2 and the counter electrode 42 in FIG. 11) of the liquid crystal light valve 64 and the scanning electrode (the electrode corresponding to the transparent electrode 14 in FIG. 2 and the scanning electrode 41 in FIG. 11). Then, the liquid crystal light valve 64 is driven by applying a voltage between them, and an image is written. At this time, the alignment state of the liquid crystal of the liquid crystal light valve 64 changes in accordance with the image.

The polarized laser light from the laser light emitting device 65 is scanned over the entire surface of the liquid crystal light valve 64 via the polygon mirror 66 and the galvano mirror 68 controlled by the printer control system 77.

The laser light incident on the liquid crystal light valve 64 is reflected by a dielectric mirror (a dielectric mirror corresponding to the dielectric mirror 23 in FIG. 2), and passes through a portion of the liquid crystal layer where the alignment state is changed. The direction of polarization of the reflected light is modulated by the electro-optic effect of the liquid crystal, and thus can be transmitted through the polarizing plate 69.

The reflected light transmitted through the polarizing plate 69 is transmitted to the imaging lens.
The data is written on the photosensitive drum 71 via the control unit 70. The image is copied by passing the image data recorded on the photosensitive drum 71 through a printing process.

The image of the original 61 is processed by digital image processing and printed by an image processing circuit 75, a laser emitting device 65, a polygon mirror 66, a mirror 67, and a galvano mirror.
This is performed using a laser scanning system composed of 72. That is, the image data stored in the image memory 74 is read out as described above,
Processed by image processing circuit 75, interface circuit
The data is transferred to the printer control system 77 via the printer.

The printer control system 77 drives the laser scanning system according to the transferred image data. That is, the laser light emitting device 65 turns on / off the laser light according to the image data.
While off, the polygon mirror 66, the mirror 67, and the galvanometer mirror 72 are scanned, and image data is written on the photosensitive drum 71. The image data written on the photosensitive drum 71 is
It is printed by going through a printing process.

The mirror 67 of the laser scanning system is configured to be inserted into the optical path when printing, and to be removed from the optical path when copying, so that the optical path is switched according to the purpose.

According to the image forming apparatus of this embodiment, since the liquid crystal light valve 10 of FIG. 2 is used in the image reading section, a scanning optical system for reading the original image is not required, and the image reading section reads the image. A compact and high-performance image forming apparatus in which the function and the image display function are combined can be realized.

In this liquid crystal light valve, the information formed in the liquid crystal layer corresponding to the address light can be read out as an optical signal and can also be read out directly as an electric signal. Simultaneously with the exposure, the image signal can be stored in the image memory, and the speed of image signal processing such as continuous copying can be increased.

Next, a description will be given of a second embodiment of the liquid crystal light valve constituting the image reading section of the image forming apparatus according to the present invention.

FIG. 12 is a sectional view showing the configuration of a second embodiment of the liquid crystal light valve constituting the image reading section of the image forming apparatus according to the present invention.

As shown in the figure, the liquid crystal light valve 80 of this embodiment comprises a fiber plate 81, a glass substrate 82, an antireflection film 83, a transparent electrode 84, a counter electrode 85, an optical waveguide 86, and a photoconductor layer 87. , Light shielding layer 88, alignment films 89 and 90, spacer 91,
A liquid crystal layer 92 and a dielectric mirror 93 are provided.

This liquid crystal light valve 80 is manufactured as follows.

First, a fiber plate which is a translucent substrate
A transparent conductive film formed by laminating ITO and SnO ₂ on 81 is deposited by sputtering, and is patterned into stripes by reactive ion etching to form a transparent electrode 84 for scanning.

Next, an amorphous silicon hydride (a-Si: H) film is formed as a photoconductor layer 87 on the transparent electrode 84. The a-Si: H film forming the photoconductor layer 87 is made of silane (S
iH ₄ ) gas and argon (Ar) gas,
It is formed by a plasma CVD method. This a-Si: H
The thickness of the film is about 7 μm.

Next, a carbon-dispersed acrylic resin is spin-coated on the photoconductor layer 87 as a light-shielding layer 88 for blocking light incident on the photoconductor layer 87 from the side of the liquid crystal layer described later. . Thereafter, a multilayer film made of titanium oxide and silicon oxide is deposited on the light shielding layer 88 by electron beam (EB) as a dielectric mirror 93 for reflecting light incident on the photoconductor layer 87 from the liquid crystal layer side. It is formed by a method.

On the side of the fiber plate 81 where the writing light 95 is incident, an antireflection film for preventing surface reflection of glass is provided.
Form 83.

Glass substrate facing fiber plate 81
A counter electrode 85 is formed on the transparent conductive film 82 by vapor deposition of a transparent conductive film made of ITO using a sputtering method.

Next, a polymer thin film is selectively polymerized on the counter electrode 85 to form an optical waveguide in a stripe shape.
Form 86.

Next, after a polyimide film is formed as the alignment films 89 and 90 by spin coating on the dielectric mirror 93 and the optical waveguide 86, respectively, the surfaces of the alignment films 89 and 90 are subjected to molecular alignment treatment by rubbing.

The fiber plate 81 and the glass substrate 82 on which the respective layers and films are formed as described above are bonded together via a spacer 91, and a nematic liquid crystal having a positive relative dielectric constant as a liquid crystal layer 92 is vacuum-injected between the substrates. Then, the liquid crystal light valve 80 is formed by sealing.

The orientation direction of the liquid crystal molecules in contact with the optical waveguide 86 is such that, when viewed from the polarization direction of light propagating through the optical waveguide 86, the refractive index of the liquid crystal is higher than that of the optical waveguide when a voltage is applied to the liquid crystal. Is set so as to increase when no voltage is applied to the liquid crystal.

The liquid crystal display mode uses a hybrid electric field effect (HFE) mode, and the liquid crystal has a twist angle of 30 ° to 60 °.
Set to. The tilt angle is preferably set to 0.05 ° to 10 °. The thickness of the liquid crystal layer 92 is about 5 μm.

Since the liquid crystal molecules are aligned on the optical waveguide 86 by the rubbing treatment, the configuration may be such that the alignment film 90 is not provided if necessary.

The glass substrate 82, the counter electrode 85, the optical waveguide 86, and the alignment film 90 of the liquid crystal light valve 80 of the second embodiment correspond to the counter substrate 94 shown in FIGS.
The liquid crystal light valve 80 includes a photodetector and a light source (not shown) corresponding to the light source 29 and the light source 30, and the operation of the liquid crystal light valve 80 is the same as the operation described with reference to FIGS.

Note that, instead of the fiber plate 81, a selfoc lens array may be used.

The fiber plate 81 and the glass substrate 82 are one embodiment of the two substrates of the present invention. The optical waveguide 86 is an embodiment of the optical waveguide of the present invention. Photoconductor layer 87 is an embodiment of the photoconductor layer of the present invention. The liquid crystal layer 92 is an embodiment of the liquid crystal layer of the present invention. The photodetector 29 shown in FIGS. 3 and 4 is an embodiment of the light receiving means of the present invention. The light source 30 shown in FIGS. 3 and 4 is an embodiment of the light source according to the present invention.

Next, another embodiment of the image forming apparatus using the liquid crystal light valve 80 of FIG. 12 as an image reading section will be described.

FIG. 13 is a system configuration diagram of another embodiment of the image forming apparatus according to the present invention.

As shown in the figure, the image forming apparatus of this embodiment includes a light source 102, a liquid crystal light valve 103, a laser light emitting device 104, a polygon mirror 105, a mirror 106, galvanomirrors 107 and 111, a polarization A plate 108, an imaging lens 109, a photosensitive drum 110, a drive control system 112, an image memory 113, an image processing circuit 114, an interface circuit 115, and a printer control system 116 are provided.

The liquid crystal light valve 103 corresponds to the liquid crystal light valve 40 in FIG. 11 and the liquid crystal light valve 80 in FIG.
It is connected to a drive control system 112.

The drive control system 112 includes a read circuit 46 included in a conversion mechanism for converting optical information into an electric signal shown in FIG.
This corresponds to a circuit including a signal processing circuit 47, a driving circuit 48, and a control circuit 49.

Laser emitting device 104, polygon mirror
105, the galvanomirror 111 and the photosensitive drum 110 are connected to a printer control system 116.

The light source 102 and the liquid crystal light valve 103 are an embodiment of the image reading section of the present invention. A laser light emitting device 104, a polygon mirror 105, a mirror 106, a galvano mirror 111, a drive control system 112, an image memory 113, an image processing circuit 114, an interface circuit 115, and a printer control system 116 are one embodiment of the image forming unit of the present invention. It is.

In this apparatus, reading of an image is performed as follows.

The light from the light source 102 is radiated on the original 101, and an image is formed on the liquid crystal light valve 103 by the reflected light from the original 101.

At this time, when the scan electrodes (the electrodes corresponding to the scan electrode 41 in FIG. 11 and the transparent electrode 84 in FIG. 12) of the liquid crystal light valve 103 are sequentially driven by the drive control system 112,
An electric signal corresponding to the image is obtained, image information data corresponding to the electric signal is stored in the image memory 113, and the image information data can be handled as a digital signal.

The copying of the original 101 is performed by using a laser scanning system. That is, the opposite electrode of the liquid crystal light valve 103 (FIG. 1)
By applying a voltage between the scan electrode (the electrode corresponding to the scan electrode 41 in FIG. 11 and the transparent electrode 84 in FIG. 12) and the scan electrode (the electrode corresponding to the scan electrode 41 in FIG. 11 and the electrode corresponding to the counter electrode 85 in FIG. 12), The liquid crystal light valve 103 is driven to write an image. At this time, the alignment state of the liquid crystal of the liquid crystal light valve 103 changes according to the image.

The polarized laser light from the laser light emitting device 104 is scanned over the entire surface of the liquid crystal light valve 103 via the polygon mirror 105 and the galvano mirror 107 controlled by the printer control system 116.

The laser light incident on the liquid crystal light valve 103 is reflected by a dielectric mirror (a dielectric mirror corresponding to the dielectric mirror 93 in FIG. 12), and passes through a portion of the liquid crystal layer where the orientation state of the liquid crystal layer is changed. The polarization direction of the reflected light is modulated by the electro-optic effect of the liquid crystal.
108 can be transmitted.

The reflected light transmitted through the polarizing plate 108 is written on the photosensitive drum 110 via the imaging lens 109. An image is copied by passing the image data recorded on the photosensitive drum 110 through a printing process.

The image of the original 101 is digitally processed and printed using an image processing circuit 114 and a laser scanning system including a laser light emitting device 104, a polygon mirror 105, a mirror 106 and a galvano mirror 111.
That is, the image data stored in the image memory 113 as described above is read, processed by the image processing circuit 114, and transferred to the printer control system 116 via the interface circuit 115.

The printer control system 116 drives the laser scanning system according to the transferred image data. That is, the laser light emitting device 104 scans the polygon mirror 105, the mirror 106, and the galvano mirror 111 while turning on / off the laser light according to the image data, and writes the image data on the photosensitive drum 110. The image data written on the photosensitive drum 110 is printed through a printing process.

The mirror 106 of the laser scanning system is configured to be inserted on the optical path for printing and removed from the optical path for copying, so that the optical path is switched according to the purpose.

According to the above-described embodiment of the image forming apparatus, since the liquid crystal light valve 80 of FIG. 12 is used in the image reading section, a scanning optical system for reading the original image is not required. Thus, a compact and high-performance image forming apparatus in which the image reading function and the image display function are combined can be realized.

In this liquid crystal light valve, the information formed in the liquid crystal layer corresponding to the address light can be read out as an optical signal and can also be read out directly as an electric signal. Simultaneously with the exposure, the image signal can be stored in the image memory, and the speed of image signal processing such as continuous copying can be increased.

The photoconductor layers of the liquid crystal light valves of the first and second embodiments shown in FIGS. 2 and 12 are made of a-Si:
H, amorphous hydrogenated silicon carbide (a-Si
_1-X C _X : H), amorphous hydrogenated silicon nitride (a-Si
_1-X N _x : H), amorphous hydrogenated silicon oxide (a-Si
_1-X O _x : H), amorphous silicon germanium hydride (a-Si _1-x Ge _x : H), cadmium sulfide (Cd
S) and Bi ₁₂ SiO ₂₀ can also be used. or,
The photoconductor layer may have a Schottky structure, a diode structure, a back-to-back diode structure, or the like.

As the light-shielding layer of the liquid crystal light valve, in addition to the carbon-dispersed acrylic resin, a pigment-dispersed organic thin film,
A thin film obtained by electroless plating a metal such as Ag on aluminum oxide (Al ₂ O ₃ ), a cermet thin film, and CdTe can be used.

As the optical waveguide of the liquid crystal light valve, in addition to a waveguide using an organic material, an inorganic material such as a-SiO _X N _Y : H or (SiO ₂ ) _X- (Ta ₂ O ₅ ) _Y hybrid is used. Waveguides using are also available.

When a nematic liquid crystal is used as a liquid crystal operation mode, a guest host mode or the like can be used in addition to the hybrid field effect mode shown in the above-described embodiment. When a smectic liquid crystal is used, a guest-host mode, an electrochromic effect, and the like can be used.

[0142]

As described above, the present invention provides a liquid crystal display.
An image reader that reads the image of a document with a light valve
Image display function to display the image of the scanned original
Forming apparatus comprising: an image reading unit having an image reading unit; and an image forming unit having a photosensitive drum.
Liquid crystal light valves have two electrodes , each with an electrode.
A substrate, a liquid crystal layer provided between two substrates, and the photoconductor layer impedance is changed by light including two one information incident is provided on the substrate of the substrate,
Dielectric mirror provided on one substrate and covering photoconductor layer
When the optical waveguide is provided on the other substrate of the two substrates, a light source for introducing light into the optical waveguide, a light receiving means for converting the light into an electric signal with receive light from a light source which propagates through the optical waveguide Bei give a image forming unit, the image reading unit
Original image data read by the image reading function
Image by exposing the photosensitive drum based on
Or by the image display function of the image reading unit.
Read light to the image displayed on the image reading unit
Irradiates from the substrate side and is reflected by the dielectric mirror
The image is exposed by exposing the photosensitive drum with light.
To form . Therefore, a compact and high-performance image forming apparatus in which the image reading function and the image displaying function are combined in the image reading unit can be realized.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a first embodiment of a liquid crystal light valve constituting an image reading unit of the image forming apparatus according to the present invention.

FIG. 3 is a plan view showing a configuration of a counter substrate included in the liquid crystal light valve of FIG. 2 constituting an image reading unit of the image forming apparatus according to the present invention.

FIG. 4 is a sectional view taken along lines AA and BB of FIG. 3;

FIG. 5B illustrates another configuration of the opposing substrate.
It is a B sectional view.

FIG. 6 is a conceptual diagram of liquid crystal molecules for explaining the refractive index of the liquid crystal molecules.

FIG. 7 is a schematic diagram showing an alignment state of liquid crystal molecules when TM mode light propagates through the optical waveguide.

FIG. 8 is a schematic diagram showing an operation state of the liquid crystal light valve in a state where no driving voltage is applied.

FIG. 9 is a schematic diagram showing an operation state of a liquid crystal light valve in a state where a driving voltage is applied.

FIG. 10 is a schematic diagram illustrating an alignment state of liquid crystal molecules when light in a TE mode propagates through an optical waveguide.

FIG. 11 is a configuration diagram of an embodiment of a conversion mechanism for converting optical information into an electric signal.

FIG. 12 is a cross-sectional view illustrating a configuration of a second embodiment of a liquid crystal light valve constituting an image reading unit of the image forming apparatus according to the present invention.

FIG. 13 is a system configuration diagram of another embodiment of the image forming apparatus according to the present invention.

FIG. 14 is a schematic configuration diagram illustrating a configuration of an image reading unit of a conventional image copying apparatus.

FIG. 15 is a block diagram showing a circuit included in a conventional image copying apparatus that converts reflected light from a document into an electric signal and sends the signal to an image processing circuit.

[Explanation of symbols]

 10, 40, 64, 80, 103 Liquid crystal light valve 11, 12, 82 Glass substrate 13, 83 Anti-reflective coating 14, 84 Transparent electrode 15, 85 Counter electrode 16, 86 Optical waveguide 17, 87 Photoconductor layer 18, 88 Shielding layer 19, 20, 89, 90 Alignment film 21, 91 Spacer 22, 92 Liquid crystal layer 23, 93 Dielectric mirror 29 Photodetector 30, 62, 102 Light source 46 Readout circuit 47 Signal processing circuit 48 Drive circuit 49 Control circuit 63 Lens 65 , 104 Laser light emitting device 66, 105 Polygon mirror 67, 106 mirror 72, 111 Galvano mirror 73, 112 Drive control system 74, 113 Image memory 75, 114 Image processing circuit 76, 115 Interface circuit 77, 116 Printer control system 81 Fiber plate

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G02F 1/135 G02F 1/13 505 G09F 9/30 G03G 15/04

Claims (2)

(57) [Claims] An image reading function having a liquid crystal light valve for reading an image of a document and displaying the read image of the document.
An image reading unit having a Shimesuru image display function, a photosensitive
An image forming apparatus comprising: an image forming unit having a body drum , wherein a liquid crystal light valve of the image reading unit includes two substrates each having an electrode, and a liquid crystal provided between the two substrates. a layer, a photoconductive layer impedance is changed by light having a pre-SL two while information is incident is provided on the substrate <br/> of the substrate, set on the one substrate
A dielectric mirror that covers the photoconductor layer, an optical waveguide provided on the other of the two substrates, a light source that introduces light into the optical waveguide, and the light source that propagates through the optical waveguide Bei give a light receiving means for converting the optical into electrical signals with receiving light from, the image forming section, the image
Documents read by the image reading function of the reading unit
Exposing the photosensitive drum based on the image data of
To form an image, or read the image
Displayed on the image reading unit by the image display function of the unit.
Irradiating the image to be read with light from the other substrate side
The light is reflected by the dielectric mirror.
An image forming apparatus for forming an image by exposing a body drum . 2. The image forming apparatus according to claim 1, wherein the substrate provided with the photoconductor layer is formed of a fiber plate.