JP5915888B2 - Alignment film processing equipment - Google Patents

Description

The present invention relates to an alignment film processing equipment, and more particularly, relates to the alignment film processing apparatus which imparts orientation controllability in the alignment film.

  The liquid crystal element has a pair of transparent substrates, a liquid crystal layer sandwiched between the transparent substrates, and an alignment film provided at an interface between the liquid crystal layer and each transparent substrate. The alignment film is provided with alignment controllability for controlling the alignment direction of the liquid crystal molecules in the liquid crystal layer according to the use of the liquid crystal element.

  For example, Patent Document 1 discloses, in paragraph No. 0027 and FIG. 20, an element manufacturing means that realizes the same function as a rectifier in a polarizing microscope.

  However, with the device manufacturing means disclosed in Patent Document 1, it is difficult to impart desired alignment controllability to the alignment film.

The present invention relates to an alignment film processing apparatus for imparting alignment controllability for controlling the alignment direction of liquid crystal molecules in a liquid crystal layer to an alignment film used in contact with the liquid crystal layer, and a light source device that emits ultraviolet light And irradiating the alignment film by reflecting the ultraviolet light from the light source device, and rotating the polarization direction of the ultraviolet light based on the alignment direction for each irradiation position of the ultraviolet light in the alignment film comprising apparatus and, a line connecting the irradiation position of the ultraviolet light in the alignment film is an alignment film processor you being a curve.

  According to the alignment film processing apparatus of the present invention, desired alignment controllability can be imparted to the alignment film.

1 is a diagram illustrating a schematic configuration of a color printer according to an embodiment of the present invention. It is FIG. (1) for demonstrating an optical scanning device. It is FIG. (2) for demonstrating an optical scanning device. It is a figure for demonstrating light source unit LU1. It is FIG. (1) for demonstrating the light source in light source unit LU1. It is FIG. (2) for demonstrating the light source in light source unit LU1. It is a figure for demonstrating light source unit LU2. It is FIG. (1) for demonstrating the light source in light source unit LU2. It is FIG. (2) for demonstrating the light source in light source unit LU2. It is FIG. (1) for demonstrating incidence | injection of the light beam to a polarization adjusting element and a polarization separation element. It is FIG. (2) for demonstrating incidence | injection of the light beam to a polarization adjusting element and a polarization separation element. It is a figure for demonstrating the element structure of a liquid crystal element. It is a figure for demonstrating the orientation of the liquid crystal molecule in a liquid crystal element. It is a figure for demonstrating the pre twist angle and twist angle in a liquid crystal element. It is a figure for demonstrating the incident surface of the scanning light which injects into a polarization splitting element. It is a figure for demonstrating the relationship between a deflection angle and an entrance plane rotation angle. It is a figure for demonstrating the light inject | emitted from a polarization separation element, when the light deflected by the polygon mirror directly injects into the polarization separation element. FIG. 5 is a diagram (No. 1) for explaining light emitted from a polarization separation element when a liquid crystal element is provided between the polarization separation element and a polygon mirror; FIG. 6 is a diagram (No. 2) for explaining light emitted from the polarization separation element when a liquid crystal element is provided between the polarization separation element and the polygon mirror. It is a figure for demonstrating the relationship between a deflection angle and the optimal polarization | polarized-light rotation angle. 6 is a diagram for explaining a relationship between a deflection angle, a twist angle, and a pre-twist angle in setting example 1. FIG. It is a figure for demonstrating the relationship between the deflection angle in the setting example 2, a twist angle, and a pre twist angle. It is FIG. (1) for demonstrating the polarization separation element by which the polarization separation surface is comprised with the dielectric multilayer. It is FIG. (2) for demonstrating the polarization separation element by which the polarization separation surface is comprised with the dielectric multilayer. It is a figure for demonstrating the effect of a polarization adjusting element in case the polarization separation surface is comprised with the dielectric multilayer. It is FIG. (1) for demonstrating the structure of an alignment film processing apparatus. It is FIG. (2) for demonstrating the structure of an alignment film processing apparatus. It is a figure for demonstrating the polarization direction of the light reflected by the rotating polygon mirror. It is a figure for demonstrating a mirror. It is a figure for demonstrating the polarization direction of the light reflected by the reflective surface of the mirror. It is a figure for demonstrating the relationship between a deflection angle and a polarization | polarized-light rotation angle about several L / R. It is a figure for demonstrating R and L. FIG. FIG. 33A is a diagram for explaining the polarization direction of light applied to the alignment film, and FIG. 33B is a diagram for explaining the alignment direction of liquid crystal molecules controlled by the alignment film. It is. It is a figure for demonstrating the relationship between the position of the y-axis direction in an alignment film, and a polarization | polarized-light rotation angle. It is a figure for demonstrating the curve of a scanning line. It is a figure for demonstrating the modification 1 of an alignment film processing apparatus. It is a figure for demonstrating the inclination | tilt angle of the light which goes to a rotary polygon mirror from the light source in the alignment film processing apparatus of the modification 1. FIG. It is a figure for demonstrating the modification 2 of an alignment film processing apparatus. It is a figure for demonstrating integration of a polarization adjusting element and a polarization separation element.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a schematic configuration of a color printer 2000 according to an embodiment.

  The color printer 2000 is a tandem multi-color printer that forms a full-color image by superimposing four colors (black, cyan, magenta, and yellow), and includes an optical scanning device 2010, four photosensitive drums (2030a, 2030b, 2030c, 2030d), four cleaning units (2031a, 2031b, 2031c, 2031d), four charging devices (2032a, 2032b, 2032c, 2032d), four developing rollers (2033a, 2033b, 2033c, 2033d), transfer A belt 2040, a transfer roller 2042, a fixing roller 2050, a paper feed roller 2054, a paper discharge roller 2058, a paper feed tray 2060, a paper discharge tray 2070, a communication control device 2080, and a printer control device 20 that comprehensively controls the above-described units. It has a such as 0.

  The communication control device 2080 controls bidirectional communication with a host device (for example, a personal computer) via a network or the like.

  The printer control device 2090 includes a CPU, a ROM described in a program written in code readable by the CPU, various data used when executing the program, a RAM as a working memory, an analog data An A / D converter or the like for converting the data into digital data. Then, the printer control device 2090 sends image information from the host device to the optical scanning device 2010.

  The photosensitive drum 2030a, the charging device 2032a, the developing roller 2033a, and the cleaning unit 2031a are used as a set, and constitute an image forming station (hereinafter also referred to as “K station” for convenience) that forms a black image.

  The photosensitive drum 2030b, the charging device 2032b, the developing roller 2033b, and the cleaning unit 2031b are used as a set, and constitute an image forming station (hereinafter also referred to as “C station” for convenience) that forms a cyan image.

  The photosensitive drum 2030c, the charging device 2032c, the developing roller 2033c, and the cleaning unit 2031c are used as a set, and constitute an image forming station (hereinafter also referred to as “M station” for convenience) that forms a magenta image.

  The photosensitive drum 2030d, the charging device 2032d, the developing roller 2033d, and the cleaning unit 2031d are used as a set, and constitute an image forming station (hereinafter also referred to as “Y station” for convenience) that forms a yellow image.

  Each photosensitive drum has a photosensitive layer formed on the surface thereof. That is, the surface of each photoconductive drum is a surface to be scanned. Each photosensitive drum is rotated in the direction of the arrow in the plane of FIG. 1 by a rotation mechanism (not shown).

  Each charging device uniformly charges the surface of the corresponding photosensitive drum.

  The optical scanning device 2010 is charged correspondingly by light modulated for each color based on multi-color image information (black image information, cyan image information, magenta image information, yellow image information) from the printer control device 2090. Each surface of the photosensitive drum is scanned. Thereby, a latent image corresponding to the image information is formed on the surface of each photosensitive drum. The latent image formed here moves in the direction of the corresponding developing roller as the photosensitive drum rotates. The configuration of the optical scanning device 2010 will be described later.

  As each developing roller rotates, the toner from the corresponding toner cartridge is thinly and uniformly applied to the surface thereof. Then, when the toner on the surface of each developing roller comes into contact with the surface of the corresponding photosensitive drum, the toner moves only to a portion irradiated with light on the surface and adheres to the surface. In other words, each developing roller causes toner to adhere to the latent image formed on the surface of the corresponding photosensitive drum so as to be visualized. Here, the toner-attached image (toner image) moves in the direction of the transfer belt 2040 as the photosensitive drum rotates.

  The yellow, magenta, cyan, and black toner images are sequentially transferred onto the transfer belt 2040 at a predetermined timing, and are superimposed to form a color image.

  Recording paper is stored in the paper feed tray 2060. A paper feed roller 2054 is disposed in the vicinity of the paper feed tray 2060. The paper feed roller 2054 takes out the recording paper one by one from the paper feed tray 2060. The recording paper is sent out toward the gap between the transfer belt 2040 and the transfer roller 2042 at a predetermined timing. As a result, the color image on the transfer belt 2040 is transferred to the recording paper. The recording paper on which the color image is transferred is sent to the fixing roller 2050.

  In the fixing roller 2050, heat and pressure are applied to the recording paper, whereby the toner is fixed on the recording paper. The recording paper on which the toner is fixed is sent to the paper discharge tray 2070 via the paper discharge roller 2058 and is sequentially stacked on the paper discharge tray 2070.

  Each cleaning unit removes toner (residual toner) remaining on the surface of the corresponding photosensitive drum. The surface of the photosensitive drum from which the residual toner has been removed returns to the position facing the corresponding charging device again.

  Next, the configuration of the optical scanning device 2010 will be described.

As shown in FIG. 2 and FIG. 3 as an example, the optical scanning device 2010 includes two light source units (LU1, LU2), two cylindrical lenses (12 ₁ , 12 ₂ ), a polygon mirror 14, and two scanning lenses. (15 ₁ , 15 ₂ ), two polarization adjusting elements (21 ₁ , 21 ₂ ), two polarization separating elements (16 ₁ , 16 ₂ ), two reflecting mirrors (17 ₁ , 17 ₂ ), four folding mirrors (18a, 18b, 18c, 18d), a scanning control device (not shown), and the like.

  Here, in the XYZ three-dimensional orthogonal coordinate system, the direction along the longitudinal direction (rotation axis direction) of each photosensitive drum is defined as the Y-axis direction, and the direction parallel to the rotation axis of the polygon mirror 14 is defined as the Z-axis direction. .

  In the following, for convenience, in each optical member, a direction corresponding to the main scanning direction is abbreviated as “main scanning corresponding direction”, and a direction corresponding to the sub scanning direction is abbreviated as “sub scanning corresponding direction”.

The light source unit LU1, as shown in FIG. 4 as an example, two light sources _(10a 1, _10b 1), two collimating lenses (11a, 11b), and has a like combining element 13 _1.

The light source 10a ₁ is mounted on the circuit board 10a ₃ together with a driving chip 10a ₂ including a light source driving circuit for driving the light source 10a ₁ .

The light source 10b ₁ is mounted on the circuit board 10b ₃ together with a driving chip 10b ₂ including a light source driving circuit for driving the light source 10b ₁ .

As an example, the light source 10a ₁ includes one semiconductor laser 101a as shown in FIG. The semiconductor laser 101a is installed such that linearly polarized light whose polarization direction is parallel to the Z-axis direction is emitted. Hereinafter, for convenience, linearly polarized light whose polarization direction is parallel to the Z-axis direction is referred to as “longitudinal polarization”. The vertically polarized light emitted from the semiconductor laser 101a is denoted as a light beam LBa.

However, instead of adjusting the installation angle of the semiconductor laser 101a, between the semiconductor laser 101a and combining element 13 ₁ in the optical path, the polarization direction of the light flux emitted from the semiconductor laser 101a vertically polarized light to the direction of An optical element such as a half-wave plate may be disposed.

Light source 10b _1, as shown in FIG. 6 as an example, include one of the semiconductor laser 101b. The semiconductor laser 101b is installed such that linearly polarized light whose polarization direction is orthogonal to the Z axis is emitted. Hereinafter, linearly polarized light whose polarization direction is orthogonal to the Z axis is referred to as “laterally polarized light” for convenience. The laterally polarized light emitted from the semiconductor laser 101b is denoted as a light beam LBb.

However, instead of adjusting the installation angle of the semiconductor laser 101b, between the semiconductor laser 101b and combining element 13 ₁ in the optical path, the polarization direction of the light flux emitted from the semiconductor laser 101b horizontally polarized light to the direction of An optical element such as a half-wave plate may be disposed.

Returning to FIG. 4, the collimating lens 11 a is disposed on the optical path of the light beam LBa emitted from the light source 10 a _1, and makes the light beam LBa substantially parallel light.

Collimator lens 11b is arranged from the light source 10b ₁ on the optical path of the light beam irradiated LBb, substantially parallel light the light beam LBb.

Combining element 13 ₁ is disposed on an optical path of the light beam LBb through the light beam LBa and the collimator lens 11b via the collimating lens 11a. The combining element 13 ₁ reflects the vertically polarized light, has a surface that transmits horizontally polarized light, as the principal ray of the principal ray and the light beam LBb light beam LBa overlap in the Z-axis direction, light beams LBa and the light beam LBb Is synthesized. Light beams LBa and the light beam LBb emitted from the light combining device 13 ₁ is emitted from the light source unit LU1. As combining element 13 ₁ can be used for polarizing beam splitter.

The light source unit LU2, as shown in FIG. 7 as an example, two light sources _{(10c 1, 10d 1),} 2 single collimating lens (11c, 11d), and has a like combining element 13 _2.

The light source 10c ₁ is mounted on the circuit board 10c ₃ together with a driving chip 10c ₂ including a light source driving circuit for driving the light source 10c ₁ . The light source 10d ₁ is mounted on the circuit board 10d ₃ together with a driving chip 10d ₂ including a light source driving circuit that drives the light source 10d ₁ .

Light source 10c _1, as shown in FIG. 8 as an example, include one of the semiconductor laser 101c. The semiconductor laser 101c is installed so that laterally polarized light is emitted. The laterally polarized light emitted from the semiconductor laser 101c is denoted as a light beam LBc.

Incidentally, the semiconductor installation angle of the laser 101c instead of adjusting, on the optical path between the semiconductor laser 101c and combining element 13 _2, the polarization direction of the light flux emitted from the semiconductor laser 101c horizontally polarized light to the direction of An optical element such as a half-wave plate may be disposed.

Light source 10d _1, as shown in FIG. 9 as an example, includes one semiconductor laser 101d. The semiconductor laser 101d is installed so that longitudinally polarized light is emitted. Note that the vertically polarized light emitted from the semiconductor laser 101d is referred to as a light beam LBd.

Incidentally, the semiconductor installation angle of the laser 101d instead of adjusting, on the optical path between the semiconductor laser 101d and combining element 13 _2, the polarization direction of the light flux emitted from the semiconductor laser 101d vertically polarized light to the direction of An optical element such as a half-wave plate may be disposed.

Returning to Figure 7, the collimator lens 11c is arranged from the light source 10c ₁ on the optical path of the light beam irradiated LBc, substantially parallel light the light beam LBc.

Collimator lens 11d is arranged from the light source 10d ₁ on the optical path of the light beam irradiated LBd, substantially parallel light the light beam LBd.

Combining element 13 ₂ is disposed on the optical path of the light beam LBd through the light beam LBc and the collimator lens 11d through the collimating lens 11c. The combining element 13 ₂ reflects the vertically polarized light, has a surface that transmits horizontally polarized light, as the principal ray of the principal ray and the light beam LBd light beam LBc overlap in the Z-axis direction, the light beam LBc and the light beam LBd Is synthesized. Light beam LBc and the light beam LBd emitted from combining element 13 ₂ is emitted from the light source unit LU2. As combining element 13 _2, it can be used polarizing beam splitter.

Returning to Figure 2, the cylindrical lens 12 _1, a light beam LBa and flux LBb emitted from the light source unit LU1, forms an image with respect to the Z-axis direction on the deflecting reflection surface near the polygon mirror 14.

The cylindrical lens 12 _2, a light beam LBc and flux LBd emitted from the light source unit LU2, forms an image with respect to the Z-axis direction on the deflecting reflection surface near the polygon mirror 14.

The polygon mirror 14 has a four-sided mirror as an example, and each mirror surface becomes a deflection reflection surface. The polygon mirror 14 constant speed about an axis parallel to the Z-axis direction, light beams LBa and flux LBb from the cylindrical lens 12 _1, a light beam LBc and flux LBd from the cylindrical lens 12 _2, perpendicular to the Z axis Deflection at a constant angular velocity in a plane.

  The light beam LBa and the light beam LBb are deflected to the −X side of the polygon mirror 14, and the light beam LBc and the light beam LBd are deflected to the + X side of the polygon mirror 14.

  The light beam surface formed by the light deflected by the deflecting / reflecting surface of the polygon mirror 14 over time is called a “deflecting surface” (see Japanese Patent Application Laid-Open No. 11-202252). Here, the deflection surface is parallel to the XY plane. Further, the angle formed between the traveling method of the light deflected by the deflecting reflecting surface and the X-axis direction is called a “deflection angle”.

Returning to FIG. 4, the scanning lens 15 ₁ is a -X side of the polygon mirror 14 is disposed on an optical path of the light beam LBa and flux LBb deflected by the polygon mirror 14.

Polarization adjusting element 21 ₁ is a -X side of the scanning lens 15 ₁ is disposed on the optical path of the light beam through the scanning lens 15 _1. Polarization adjusting element 21 ₁ converts the polarization state of the light beam emitted from the scanning lens 15 ₁ (light beam LBa and the light beam LBb), the subsequent state easily polarized light separated by the polarization separation element 16 _1.

Polarization separation element 16 ₁ is a polarization adjusting element 21 ₁ of the -X side is disposed on the optical path of the light beam emitted from the polarization adjustment element 21 _1. Then, as shown in FIG. 10, the light beam LBa and the light beam LBb are separated by transmitting the light beam LBa and reflecting the light beam LBb in the −Z direction.

Light beam transmitted through the polarization separation element 16 ₁ (here, the light beam LBa) is irradiated to the surface of the photosensitive drum 2030a via the folding mirror 18a and the dustproof glass 19a.

On the other hand, (in this case, the light beam LBb) reflected in the -Z direction by the polarization separation element 16 ₁ light beam is reflected in the + X direction by the reflection mirror 17 _1, via a folding mirror 18b and the dustproof glass 19b photoreceptor The surface of the drum 2030b is irradiated.

Scanning lens 15 _2, a + X side of the polygon mirror 14 is disposed on an optical path of the light beam LBc and flux LBd deflected by the polygon mirror 14.

Polarization adjusting element 21 ₂ is a scanning lens 15 ₂ + X side, it is disposed on the optical path of the light beam through the scanning lens 15 _2. Polarization adjusting element 21 ₂ converts the polarization state of the light beam emitted from the scanning lens 15 ₂ (light beam LBc and the light beam LBd), the subsequent state easily polarized light separated by the polarization separating element 16 _2.

Polarization separating element 16 ₂ is a polarization adjusting element 21 ₂ of the + X side, it is disposed on the optical path of the light beam emitted from the polarization adjustment element 21 _2. Then, as shown in FIG. 11, the light beam LBc and the light beam LBd are separated by transmitting the light beam LBd and reflecting the light beam LBc in the −Z direction.

(In this case, the light beam LBc) light beam reflected in the -Z direction by the polarization separating element 16 ₂ is reflected in the -X direction by the reflection mirror 17 _2, the photosensitive drum via the folding mirror 18c and the dust-proof glass 19c The surface of 2030c is irradiated.

On the other hand, (in this case, the light beam LBd) light beam transmitted through the polarization separating element 16 ₂ is applied to the surface of the photosensitive drum 2030d via a folding mirror 18d and the dustproof glass 19d.

Mirrors 18a folded and the scanning lens 15 ₁ and the polarization adjustment element 21 ₁ and the polarization beam splitter 16 ₁ is a scanning optical system of the "K station". Mirror 18b folded and the scanning lens 15 ₁ and the polarization adjustment element 21 ₁ and the polarization beam splitter 16 ₁ and the reflection mirror 17 ₁ is a scanning optical system of the "C station". That is, the scanning lens 15 ₁ and the polarization adjustment element 21 ₁ and the polarization beam splitter 16 ₁ is shared by two image forming stations.

Mirror 18c folded between the scanning lens 15 ₂ and the polarization adjustment element 21 ₂ and the polarization separating element 16 ₂ and the reflection mirror 17 ₂ is a scanning optical system of the "M station". Mirror 18d and the dustproof glass 19d folded and the scanning lens 15 ₂ and the polarization adjustment element 21 ₂ and the polarization separating element 16 ₂ is a scanning optical system of the "Y station". That is, the scanning lens 15 ₂ and the polarization adjustment element 21 ₂ and the polarization separating element 16 ₂ is shared by the two image forming stations.

  Each folding mirror is provided so that the optical path lengths at the respective image forming stations are equal to each other.

  The light spot on each photosensitive drum moves in the longitudinal direction of the photosensitive drum as the polygon mirror 14 rotates. The moving direction of the light spot at this time is the “main scanning direction”, and the rotation direction of the photosensitive drum is the “sub scanning direction”.

  Incidentally, a scanning area in the main scanning direction in which image information is written on each photosensitive drum is called an “effective scanning area”, an “image forming area”, or an “effective image area”.

The scanning control device drives the light source 10a ₁ according to the black image information, drives the light source 10b ₁ according to the cyan image information, drives the light source 10c ₁ according to the magenta image information, and according to the yellow image information. It drives the light source 10d _1.

  Therefore, the light beam LBa that irradiates the surface of the photoconductor drum 2030a, the light beam LBb that irradiates the surface of the photoconductor drum 2030b, the light beam LBc that irradiates the surface of the photoconductor drum 2030c, and the light beam LBd that irradiates the surface of the photoconductor drum 2030d. , A luminous flux for writing.

  On the other hand, a light beam LBb that irradiates the surface of the photoconductor drum 2030a, a light beam LBa that irradiates the surface of the photoconductor drum 2030b, a light beam LBd that irradiates the surface of the photoconductor drum 2030c, and a light beam LBc that irradiates the surface of the photoconductor drum 2030d. , Ghost light.

  In this embodiment, a resin lens is used as each scanning lens. The resin lens can be easily processed into an aspherical shape, can easily obtain desired optical performance, and can be manufactured at a lower cost than a glass lens.

  However, the resin lens is disadvantageous in that it tends to cause birefringence. In this case, the polarization state of the incident light changes due to birefringence, and for example, a phenomenon occurs in which the polarization changes from linearly polarized light to elliptically polarized light, or the polarization direction rotates.

  If a polarization separation element is provided at the subsequent stage of the scanning lens, if the polarization state of the incident light changes in the scanning lens, the polarization separation element cannot perform desired polarization separation. That is, the ghost light is likely to be generated.

  Therefore, in this embodiment, a polarization adjustment element is provided between the scanning lens and the polarization separation element.

Polarization adjusting element 21 _1, as shown in FIG. 12 as an example, a pair of transparent substrates (2101a, 2101b), the transparent nematic liquid crystal layer 2104 is sandwiched between the substrates, the interface between the nematic liquid crystal layer 2104 each transparent substrate A liquid crystal element having alignment films (2103a, 2103b) and the like provided on the substrate. Each alignment film is a film provided for the purpose of controlling the alignment direction of liquid crystal molecules in the nematic liquid crystal layer 2104. The polarization adjustment element 21 ₂ is also a view similar to the liquid crystal element. Therefore, in the following description the polarization adjustment element 21 ₁ as a representative.

  As each transparent substrate, a plate-like member or a film-like member such as a transparent glass having a desired light transmittance, a transparent resin, or a translucent ceramic can be used depending on the application.

  Each alignment film is formed of a material whose surface properties are changed by light irradiation (hereinafter referred to as “alignment film material”). The change in the surface property is caused by, for example, (1) main chain is cut, (2) side chain is cut, (3) side chain direction is changed, (4) cross-linking is performed.

  Examples of such alignment film materials include PVC (polyvinyl cinnamate), polyimide (for example, SE-610, SE-7792 manufactured by Nissan Chemical Co., Ltd.), modified polysilane having a cinnamoyl group introduced therein, and long wavelength light. Examples thereof include a material into which a chalcone group is introduced so that photodimerization proceeds.

  The thickness of the nematic liquid crystal layer 2104 is usually about 1 μm to 100 μm, and is set according to the application and material.

  An outline of the manufacturing process of the liquid crystal element will be described.

(A) An alignment film is formed by applying an alignment film material to the surfaces of each of the two transparent substrates to be the pair of transparent substrates by spin coating, flexographic printing, or the like. When the size of each transparent substrate corresponds to a plurality of liquid crystal elements, an alignment film material is applied in accordance with a region where a nematic liquid crystal layer is formed in each liquid crystal element.
(B) Pre-baking and post-baking are performed.
(C) Alignment controllability for controlling the alignment direction of liquid crystal molecules is imparted to each alignment film.
(D) A spacer for forming a space (gap) having a predetermined thickness is dispersed on each alignment film.
(E) An adhesive is applied to a portion other than the liquid crystal inlet around the region where the nematic liquid crystal layer is formed on at least one transparent substrate.
(F) Two transparent substrates are bonded together.
(G) When the size of each transparent substrate corresponds to a plurality of liquid crystal elements, it is cut into individual cells by a method such as scribing or dicing.
(H) A nematic liquid crystal is injected into the space (gap) in each cell from the liquid crystal injection port using a capillary method.
(I) A sealing material is applied to the liquid crystal inlet, and the liquid crystal inlet is sealed.

  Hereinafter, the alignment direction of the liquid crystal molecules controlled by the alignment film having the alignment controllability is also referred to as an “alignment control direction” for convenience.

  In the liquid crystal element manufactured as described above, when two alignment films provided with the nematic liquid crystal layer 2104 interposed therebetween have different alignment control directions at positions facing each other, an example is shown in FIG. As described above, the nematic liquid crystal layer 2104 has a twist structure in which the alignment direction of liquid crystal molecules gradually changes from the alignment control direction on one side to the alignment control direction on the other side. Note that the broken line in FIG. 13 indicates the position of the nematic liquid crystal layer 2104 in the thickness direction (X-axis direction).

  In the following, the angle formed by the alignment control direction and the Y-axis direction in the alignment film 2103a on the light incident side is referred to as “pre-twist angle” (see FIG. 14). In addition, an angle formed by the alignment control direction in the alignment film 2103b on the light emission side and the alignment control direction at the opposite position in the alignment film 2103a is referred to as “twist angle” (see FIG. 14).

  By the way, the incident surface of the polarization separation element is inclined in accordance with the traveling direction of light incident on the polarization separation element (hereinafter also referred to as “scanning light”), that is, the deflection angle (see FIG. 15). Hereinafter, for the sake of convenience, the tilt angle with respect to the incident surface of the scanning light having a deflection angle of 0 ° is referred to as “incident surface rotation angle”. In addition to the deflection angle, the incident surface rotation angle also depends on the angle formed by the normal line of the incident side surface of the polarization separation element (here, the polarization separation surface) and the deflection surface.

  When the light incident on the polarization separation element is linearly polarized light and the polarization direction is constant regardless of the incident angle, and the incident surface rotation angle is not 0 °, the incident surface rotation angle is different, The ratio of the p-polarized component and the s-polarized component in the incident light on the separation surface is different. Therefore, the intensity of the light transmitted through the polarization separation element and the intensity of the light reflected by the polarization separation element differ depending on the magnitude of the incident surface rotation angle.

  FIG. 16 shows the calculation of the relationship between the incident surface rotation angle and the deflection angle when the angle between the normal of the incident side surface of the polarization separation element (here, the polarization separation surface) and the deflection surface is 55 °. Results are shown. According to this, when the deflection angle changes, the magnitude of the incident surface rotation angle also changes. Therefore, when the deflection angle is different, the intensity of the light transmitted through the polarization separation element and the intensity of the light reflected by the polarization separation element are different.

  FIG. 17 shows a case where the longitudinally polarized light deflected by the polygon mirror is directly incident on the polarization separation element. At a deflection angle of 0 °, the longitudinally polarized light is only the p-polarized component, and most of the scanning light is transmitted through the polarization separation surface. However, when the absolute value of the deflection angle increases, the s-polarized component increases, and a component reflected by the polarization separation surface is generated, resulting in polarization separation failure.

  FIG. 18 shows a case where a liquid crystal element is provided between the polarization separation element and the polygon mirror. The liquid crystal element emits light by rotating the polarization direction of the longitudinally polarized light deflected by the polygon mirror in a polarization direction suitable for the subsequent polarization separation element, that is, a direction parallel to the incident surface of the polarization separation element. Therefore, in the polarization separation element, almost all light passes through the polarization separation surface regardless of the deflection angle, and the polarization separation failure can be greatly reduced.

  FIG. 19 shows a case where incident light is laterally polarized light with the same configuration as FIG. The liquid crystal element emits light by rotating the polarization direction of the light deflected by the polygon mirror in a direction perpendicular to the incident surface of the polarization separation element. Therefore, in the polarization separation element, almost all light is reflected by the polarization separation surface regardless of the deflection angle, and polarization separation defects can be greatly reduced.

  Hereinafter, the rotation angle when the polarization direction is rotated in the liquid crystal element is abbreviated as “polarization rotation angle”.

  FIG. 20 shows the relationship between the optimum polarization rotation angle and deflection angle in the liquid crystal element. This optimum polarization rotation angle coincides with the incident surface rotation angle (see FIG. 16).

  Next, an example of setting the pre-twist angle and the twist angle in the liquid crystal element having the relationship between the optimum polarization rotation angle and the deflection angle will be described.

  FIG. 21 shows a setting example 1 of the pre-twist angle and the twist angle. In this setting example 1, the pre-twist angle is set to 90 degrees regardless of the deflection angle, and the relationship between the twist angle and the deflection angle is substantially matched with the relationship of FIG. Setting example 1 is effective when the thickness of the liquid crystal layer is sufficiently thick, the twist of the liquid crystal molecules in the liquid crystal layer is gentle, and the polarization rotation angle can be made to coincide with the twist angle. Setting example 1 is a calculated value obtained by setting the thickness of the liquid crystal layer to 20 μm. In this case, since the pre-twist angle does not change, there is an advantage that the alignment accuracy when the two transparent substrates are bonded can be relaxed.

  FIG. 22 shows a setting example 2 of the pre-twist angle and the twist angle. In setting example 2, when the deflection angle changes, both the pre-twist angle and the twist angle change. The relationship between the pre-twist angle and the deflection angle and the relationship between the twist angle and the deflection angle are all different from the relationship between the optimum polarization rotation angle and the deflection angle (see FIG. 20). Setting example 2 is effective when the liquid crystal layer is thin. Setting example 2 is a calculated value obtained by setting the thickness of the liquid crystal layer to 5 μm. In setting example 2, the degree of polarization of light emitted from the liquid crystal element can be made higher than in setting example 1.

  By the way, the derivation of the pre-twist angle and the twist angle is obtained when the polarization state (measured value) of light incident on the liquid crystal element and the polarization state (set value) of light emitted from the liquid crystal element are expressed by Jones vectors, respectively. It is preferable to obtain a Jones matrix of the liquid crystal element in which the Jones vector of the emitted light is closest to the set value. The Jones matrix representation of the liquid crystal element is described in, for example, Colin Soutar and Kanghua Lu, “Determination of the physical properties of an arbitrary-twisted-neutral liquid crystal”. 33, no. 8, P 2704-2712 (1994). An optimum solution may be obtained using a commercially available simulator.

  In the liquid crystal element, the tilt angle of the liquid crystal molecules may be added to a setting target for realizing the optimum relationship between the polarization rotation angle and the deflection angle.

  In the present embodiment, a liquid crystal element having a relationship between the optimum polarization rotation angle and deflection angle is used as each polarization adjusting element. Thereby, the polarization separation failure in each polarization separation element can be suppressed. Further, even when the liquid crystal element is enlarged or lengthened, the manufacturing cost can be kept low.

  Next, a polarization separation element suitable for use in combination with the liquid crystal element will be described. Hereinafter, a combination of a liquid crystal element and a polarization separation element is referred to as a “polarization separation device”.

  This polarization separation element has a polarization separation surface formed by a dielectric multilayer film. The polarization separation surface is inclined at a predetermined angle with respect to the deflection surface. Here, the polarization separation surface transmits p-polarized light and reflects s-polarized light. Hereinafter, this polarization separation element is also referred to as a “dielectric multilayer element”.

  Glass or transparent resin can be used for the transparent substrate that supports the polarization separation surface. As the shape of the transparent substrate, a plate type shown in FIG. 23 as an example, or a prism type shown in FIG. 24 as an example is selected. Since the former has a simpler structure and fewer manufacturing steps than the latter, it can be manufactured relatively inexpensively. On the other hand, the latter can make the optical path lengths of the reflected light and the transmitted light equal, and since no “bend” occurs in the transmitted light, it is easy to ensure optical performance.

  Here, a polarization separation surface is provided so that the polarization direction of incident light is parallel or perpendicular to the incident surface, and can transmit longitudinally polarized light and reflect laterally polarized light.

The thickness of the dielectric multilayer film can be designed using a so-called optical simulator with the refractive index of the dielectric material used, the range of the deflection angle requiring polarization separation, and the wavelength of incident light as parameters. As the dielectric material, titanium dioxide (TiO ₂ ) can be used as a high refractive index material, and silicon dioxide (SiO ₂ ) can be used as a low refractive index material.

  When the light deflected by the polygon mirror is longitudinally polarized light, it is desirable that only the transmitted light is obtained from the polarization separation element and no reflected light is generated. At this time, when the incident light is modulated according to the image information, the transmitted light is called “signal light” and the reflected light is called “ghost light”. On the other hand, when the light deflected by the polygon mirror is horizontally polarized light, it is desirable that only the reflected light is obtained from the polarization separation element and no transmitted light is generated. At this time, when the incident light is modulated according to the image information, the reflected light is called “signal light” and the transmitted light is called “ghost light”.

Here, in order to quantify the quality of polarization separation in the polarization separation element, a “ghost light intensity ratio” is introduced. Assuming that the light intensity of the signal light emitted from the polarization separation element is I _a and the light intensity of the ghost light emitted from the polarization separation element is I _b , the ghost light intensity ratio R (%) is _expressed by the following equation (1). I will represent it.
R = I _b / I _a × 100 (1)

  FIG. 25 shows the ghost light when the polarization separation device is disposed on the longitudinally polarized light path deflected by the polygon mirror and when only the dielectric multilayer element is disposed on the light path. The measurement result of the intensity ratio is shown. By using the polarization separation device, it can be confirmed that the ghost light intensity ratio can be reduced as a whole regardless of the angle of view.

  FIG. 26 shows an alignment film processing apparatus 1000 used for imparting the alignment controllability to each alignment film of a liquid crystal element.

  The alignment film processing apparatus 1000 includes a light source device 1011, a polygon scanner 1012, a mirror 1013, a stage device 1014, a control device 1015 for controlling the whole (not shown in FIG. 26, see FIG. 27), and the like.

  Here, in the xyz three-dimensional orthogonal coordinate system, a plane parallel to the floor surface on which the alignment film processing apparatus 1000 is placed is defined as an xy plane.

  The light source device 1011 has a light source that emits ultraviolet light having a wavelength of 200 nm to 400 nm. Examples of a light source that emits ultraviolet light in this wavelength range include a xenon lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a He-Cd laser, and an Nd-YAG laser.

  Here, as the light source, a laser that emits the above-mentioned ultraviolet light of linearly polarized light (longitudinal polarized light) whose polarization direction is parallel to the z-axis direction is used. Note that the light source device 1011 may include a band-pass filter that removes light other than a necessary wavelength in order to avoid an increase in temperature. When a light source that emits light that is not linearly polarized light is used, the light source device 1011 includes a polarization filter that converts the light emitted from the light source into linearly polarized light.

  The polygon scanner 1012 is an eight-sided mirror as the rotary polygon mirror 1121, a driving device 1122 (see FIG. 27) that rotates the rotary polygon mirror 1121 at a predetermined rotation speed, and a rotation for detecting the rotation angle of the rotary polygon mirror 1121. A sensor 1123 (see FIG. 27) and the like are included. Each mirror surface in the rotating polygon mirror 1121 reflects light from the light source device 1011. The rotary polygon mirror 1121 has a rotation axis parallel to the z-axis direction, and is rotated in the direction of the arrow in FIG.

  Both the light incident on the rotating polygon mirror 1121 and the light reflected by the rotating polygon mirror 1121 are in a plane parallel to the xy plane. Therefore, the polarization direction of the light reflected by the rotating polygon mirror 1121 is parallel to the z-axis direction (see FIG. 28).

  Hereinafter, an angle formed by the traveling method of the light reflected by the rotary polygon mirror 1121 and the x-axis direction is referred to as a “deflection angle”.

  The stage device 1014 includes a stage 1141 on which a transparent substrate on which an alignment film is formed is placed, a driving device 1142 for moving the stage 1141 (see FIG. 27), and a position sensor 1143 for detecting the position of the stage 1141 ( 27). Here, the stage 1141 is moved along the x-axis direction.

  The stage apparatus 1014 has an electrostatic adsorption mechanism or a suction adsorption mechanism for fixing the transparent substrate to the stage 1141 so that the transparent substrate does not shift on the stage 1141 when the stage 1141 moves. .

  The mirror 1013 is disposed on the optical path of the light reflected by the polygon scanner 1012, and reflects the light in the direction toward the stage 1141. In this case, as the rotary polygon mirror 1121 rotates, the deflection angle of the light toward the mirror 1013 changes, and the incident position of the light incident on the mirror 1013 changes. Therefore, when a transparent substrate on which an alignment film is formed is placed on the stage 1141, the alignment film is scanned with light reflected by the mirror 1013 as the rotary polygon mirror 1121 rotates.

  As shown in FIG. 29 as an example, the reflecting surface of the mirror 1013 is a surface on which a dielectric multilayer film that absorbs little light is formed, and is curved. Therefore, the scanning line that is the locus of the light that scans the alignment film becomes a curve, and the polarization direction of the light that scans the alignment film changes depending on the irradiation position (see FIG. 30). Here, the polarization direction of the incident linearly polarized light is rotated and irradiated to the alignment film.

  The dielectric multilayer film is designed so that the phase difference of reflected light is as small as possible. If the phase difference is large, the incident linearly polarized light may become elliptically polarized light. In addition, the surfaces of the mirror 1013 other than the reflection surface are coated with a light shielding member in order to prevent ultraviolet light from entering.

  FIG. 31 shows the light incident on the mirror 1013 when the radius of curvature R of the reflecting surface of the mirror 1013 is changed with respect to the distance L (see FIG. 32) from the rotary polygon mirror 1121 to the center of the mirror 1013. The relationship between the deflection angle and the rotation angle of the polarization direction of the light reflected by the mirror 1013 (hereinafter abbreviated as “polarization rotation angle”) is shown. The mirror installation angle (see FIG. 29) is 45 degrees. Here, regarding the deflection angle and the polarization rotation angle, the + x direction is 0 °, and the counterclockwise angle with respect to the + x direction is a plus. The radius of curvature R is positive when the reflecting surface is convex and negative when the reflecting surface is concave.

  For example, when L / R = 1.0, all light is incident on the reflecting surface at an incident angle of 45 degrees and is reflected to the −z side. In addition, the polarization directions of the incident light and the reflected light are both within the incident plane. For this reason, the polarization direction of the light irradiated to the alignment film undergoes rotation equal to the deflection angle. In this case, the polarization direction of light applied to the alignment film is shown in FIG. The alignment control direction in the alignment film at this time is shown in FIG. The direction orthogonal to the polarization rotation angle is the orientation control direction.

  FIG. 34 shows the relationship between the position in the y-axis direction of the alignment film and the polarization rotation angle when the mirror installation angle is 45 °, the maximum deflection angle is 30 °, and L = R = 400 mm. . Here, y = 0 is a position where light having a deflection angle of 0 ° is irradiated.

  If the deviation of the polarization direction after rotation is not large, the reflecting surface may be a shape obtained by joining planar regions instead of a curved shape.

  The provision of alignment controllability by ultraviolet light irradiation may depend not only on the polarization direction but also on the incident direction and incident angle with respect to the alignment film. Therefore, it is preferable to reduce the difference between the incident direction and the incident angle depending on the incident position. Further, a light condensing system may be used so that the light source device 1011 has a conjugate relationship on the alignment film.

  The material of the main body of the mirror 1013 is preferably glass from the viewpoints of strength against thermal deformation, surface smoothness, resistance to ultraviolet light, and the like. When the curved shape of the reflecting surface is not a spherical surface but a free curved surface, a resin material that can obtain the surface shape relatively easily may be used. In this case, it is preferable to select a resin material that is resistant to ultraviolet light emitted from the light source device 1011.

  Incidentally, Patent Document 1 discloses a lens that switches the polarization direction of incident light. In this case, since the ultraviolet light passes through the lens, the light utilization efficiency is reduced due to light absorption and the lens is more easily deteriorated by the ultraviolet light than the mirror.

  The control device 1015 turns on and off the light source device 1011. Further, the control device 1015 controls the driving device 1122 of the polygon scanner 1012 based on the output signal of the rotation sensor 1123 to rotate and stop the rotating polygon mirror 1121. Then, the control device 1015 controls the driving device 1142 of the stage device 1014 based on the output signal of the position sensor 1143 to position the stage 1141. Further, the control device 1015 controls the drive signal of the light source device 1011 in synchronization with the output signal of the rotation sensor 1123 so that the intensity of light on the alignment film is uniform regardless of the irradiation position.

  Note that a light shielding member may be provided so that light does not reach other than a predetermined region of the alignment film. Depending on the material of the alignment film, a temperature / humidity adjusting mechanism for maintaining the temperature and humidity of the alignment film at a predetermined temperature and humidity may be provided. Furthermore, in order to prevent the alignment film from being oxidized, an inert gas replacement mechanism may be provided in which the periphery of the alignment film is an inert gas atmosphere.

Next, the operation of the control device 1015 when providing the alignment controllability to the alignment film will be described. Note that a transparent substrate on which an alignment film is formed is already placed on the stage 1141.
(1) Based on the output signal of the position sensor 1143, the driving device 1142 is controlled to move the stage 1141 to a predetermined start position.
(2) The light source device 1011 is turned on and the driving device 1122 is controlled to rotate the rotary polygon mirror 1121. As a result, the light irradiated to the alignment film moves as the rotary polygon mirror 1121 rotates. That is, the alignment film is scanned with ultraviolet light. The scanning line at this time is curved to the −x side as shown in FIG. 35 as an example. At this time, the drive signal of the light source device 1011 is controlled in synchronization with the output signal of the rotation sensor 1123 so that the intensity of light on the alignment film becomes uniform regardless of the irradiation position.
(3) Based on the output signal of the rotation sensor 1123, the timing at which the mirror surface where the light from the light source device 1011 is reflected shifts to the next mirror surface is detected, and the stage immediately before or immediately after the mirror surface shifts to the next mirror surface. The driving device 1142 is controlled while monitoring the position of the stage 1141 based on the output signal of the position sensor 1143 so that the 1141 moves by a predetermined distance in the + x direction.
(4) The process (3) is repeated until the stage 1141 reaches a predetermined final position.
(5) When the stage 1141 reaches a predetermined final position, the light source device 1011 is turned off and the rotation of the rotary polygon mirror 1121 is stopped.

  By the way, in the element manufacturing means disclosed in Patent Document 1, there is no explanation about the principle of polarization rotation in the lens, and if the polarization rotation is caused by the difference in transmittance between p-polarized light and s-polarized light, it depends on the position. The difference in the amount of light is expected to be large, and there is a disadvantage that the alignment regulation force is likely to be uneven. In addition, since the lens has an air interface, there is a high possibility that a mixture of polarized light will occur due to multiple reflections here, and it is difficult to obtain high-quality linearly polarized light. Furthermore, a lens having a size equal to or larger than that of the alignment film is required, and it is difficult to cope with a large alignment film.

  As described above, the alignment film processing apparatus 1000 according to this embodiment includes the light source device 1011, the polygon scanner 1012, the mirror 1013, the stage device 1014, the control device 1015, and the like.

  The light source device 1011 emits ultraviolet light. The polygon scanner 1012 has a rotating polygon mirror 1121 and deflects light from the light source device 1011. The stage device 1014 includes a stage 1141 on which a transparent substrate on which an alignment film is formed is held, and a driving device 1142 that moves the stage 1141 along the x-axis direction. The mirror 1013 is arranged on the optical path of the light deflected by the polygon scanner 1012, rotates the polarization direction of the light according to the incident position, and reflects it in the direction toward the alignment film. In this case, it is possible to irradiate linearly polarized light having a better degree of polarization than before, while changing the polarization direction depending on the position of the alignment film.

  Further, since the reflecting surface of the mirror 1013 is curved according to the required alignment control direction, desired alignment controllability can be easily imparted to the alignment film.

  In addition, since the control device 1015 controls the drive signal of the light source device 1011 so that the intensity of ultraviolet light on the alignment film is uniform regardless of the irradiation position, the desired alignment controllability can be achieved with higher accuracy. Can be imparted to the alignment film.

  In addition, since the mirror 1013 is used, light utilization efficiency and durability against ultraviolet light can be improved as compared with the case of using a lens.

  Therefore, the alignment film processing apparatus 1000 can cope with a large alignment film, and can impart desired alignment controllability to the alignment film.

  According to the optical scanning device 2010 according to the present embodiment, each polarization adjusting element includes a pair of transparent substrates (2101a and 2101b), a nematic liquid crystal layer 2104 and a nematic liquid crystal layer 2104 sandwiched between the transparent substrates, and each transparent substrate. This is a liquid crystal element having an alignment film (2103a, 2103b) and the like provided at the interface of the substrate. Each alignment film in the liquid crystal element is given alignment controllability by the alignment film processing apparatus 1000. Therefore, this liquid crystal element can have a desired polarization adjustment function. Moreover, even if the liquid crystal element is increased in area or lengthened, the manufacturing cost can be kept low.

  In addition, since the polarization adjusting element is provided between the polarization separation element and the polygon mirror, the polarization separation characteristic of the polarization separation element can be improved as compared with the conventional case. That is, generation of ghost light (noise light) can be reduced as compared with the conventional case.

  Further, since the scanning lens and the polarization separation element are shared by the two image forming stations, it is possible to reduce the size and the cost.

  Therefore, the optical scanning device 2010 can be miniaturized without causing an increase in cost, and can form a high-quality latent image on each photosensitive drum.

  The color printer 2000 according to the present embodiment includes the optical scanning device 2010. As a result, the color printer 2000 can be downsized without increasing the cost and degrading the image quality.

  Here, a modified example of the alignment film processing apparatus 1000 will be described. In the following description, differences from the above-described embodiment will be mainly described, and the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description thereof will be simplified or omitted.

  FIG. 36 shows an alignment film processing apparatus 1000A that is a first modification. This alignment film processing apparatus 1000A is characterized in that, instead of the polygon scanner 1012 and the mirror 1013, a polygon scanner 1016 including a rotating polygon mirror 1161 whose mirror surfaces have the same functions as the mirror 1013 is used. ing.

  The rotation axis of the rotating polygonal mirror 1161 is parallel to the x-axis. The light incident on the polygon scanner 1016 is parallel to the xy plane, but is inclined with respect to the y-axis direction so that the polarization direction of the light irradiated to the alignment film becomes a desired polarization direction (FIG. 37). reference). This inclination angle is set based on the orientation control direction. Compared to the above embodiment, the application range in the orientation control direction is narrow, but there is an advantage that the number of parts can be reduced.

  FIG. 38 shows an alignment film processing apparatus 1000B that is a second modification. This alignment film processing apparatus 1000B is characterized in that an optical system 1170 is used instead of the polygon scanner 1012.

  Here, the optical system 1170 includes two cylindrical lenses (1171, 1172) and a slit plate 1173.

  The cylindrical lens 1171 makes light emitted from the light source device 1011 substantially parallel light in the z-axis direction.

  The cylindrical lens 1172 is disposed on the optical path of the light passing through the cylindrical lens 1171, and changes the divergence of the light in a plane parallel to the xy plane.

  Each cylindrical lens is set so that the lens power direction and the polarization direction of incident light are orthogonal or parallel to each other. In this case, rotation of the polarization direction and elliptical polarization in the cylindrical lens can be suppressed with respect to the incident light. As the material of each cylindrical lens, a material having high ultraviolet light transparency and excellent durability, such as quartz, is preferable.

  The slit plate 1173 is disposed on the optical path of light through the cylindrical lens 1172, and has a slit for limiting the width of the light in the z-axis direction. In this case, the light irradiation area on the alignment film is limited. And the polarization direction in each irradiation position can be made into a more desirable polarization direction.

  Unlike the alignment film processing apparatus 1000 and the alignment film processing apparatus 1000A, the alignment film processing apparatus 1000B irradiates the alignment film with light that has spread linearly. However, it is difficult to adjust the light intensity according to the irradiation position.

  In the above embodiment, a magnetic Faraday rotator that actively modulates the polarization direction of light in accordance with the rotation of the rotary polygon mirror 1121 may be used. In this case, the degree of freedom in setting the polarization direction can be further increased.

  In the above embodiment, when a lamp light source is used as the light source of the light source device 1011, it is preferable to use an elliptical reflector that reflects divergent light emitted from the lamp light source. In this case, when the first focal point of the elliptical reflector is made coincident with the light emitting portion position of the lamp light source, the reflected light from the elliptical reflector is condensed on the second focal point, so that the position of the second focal point is the light emission of the laser. What is necessary is just to set so that it may correspond with a part position substantially. However, in the case of a lamp light source, since the polarization direction is usually not uniform, it is necessary to provide a polarizer on the optical path between the light source device 1011 and the polygon scanner 1012. As the polarizer, a wire grid polarizer having a wide range of application of incident angles is preferable. In the alignment film processing apparatus 1000B, it is preferable to provide a polarizer near the slit.

  In the above embodiment, a collimating lens for converting light from the light source device 1011 into parallel light or substantially convergent light that forms an image on the alignment film on the optical path between the light source device 1011 and the polygon scanner 1012; At least one of an aperture plate that has an aperture and restricts the beam diameter of light and a cylindrical lens that corrects surface tilt in the polygon scanner 1012 may be provided.

  In the above embodiment, the case where the rotary polygon mirror 1121 of the polygon scanner 1012 is an octahedral mirror has been described.

  In the above embodiment, instead of the polygon scanner 1012, a galvanometer mirror whose mirror is oscillated may be used.

  Moreover, in the said embodiment, as FIG. 39 shows as an example, you may integrate the said polarization separation element and the said polarization adjustment element. In this case, the number of interfaces on the optical path is reduced, and wavefront aberration can be reduced. And cost reduction can be achieved by sharing parts. Further, the assembly process and adjustment process in the optical scanning device can be simplified.

  Moreover, although the said embodiment demonstrated the case where each light source of an optical scanning device had one light emission part, it is not limited to this. For example, each light source may have a plurality of semiconductor lasers. Each light source may have a semiconductor laser array having a plurality of light emitting portions.

  In the above embodiment, the image forming apparatus in which the toner image is transferred from the photosensitive drum to the recording paper via the transfer belt has been described. However, the present invention is not limited to this, and the toner image is directly transferred to the recording paper. The image forming apparatus may be used.

  In the above embodiment, the color printer 2000 having four photosensitive drums as the image forming apparatus has been described. However, the present invention is not limited to this. For example, a printer having two photosensitive drums may be used. Further, it may be a multi-color printer that uses auxiliary colors.

  Further, an image forming apparatus using a color developing medium (positive photographic paper) that develops color by the heat energy of a beam spot as an image carrier may be used. In this case, a visible image can be directly formed on the image carrier by optical scanning.

  In the above embodiment, the case where the optical scanning device is used in a printer has been described. However, the optical scanning device may be an image forming apparatus other than a printer, for example, a copier, a facsimile, or a multifunction machine in which these are integrated. Also suitable.

10a _{1 to} 10d ₁ ... light source, 12 ₁ , 12 ₂ ... cylindrical lens, 14 ... polygon mirror (light deflector), 15 ₁ , 15 ₂ ... scanning lens, 16 ₁ , 16 ₂ ... polarization separation element, 17 ₁ , 17 ₂ ... reflecting mirror, 18a, 18b, 18c, 18 d ... folding mirror, 19 a to 19 d ... _dust-21 1, 21 2 _... polarization adjusting element (liquid crystal element), 1000 ... alignment film processing apparatus, 1000A ... alignment film treatment apparatus , 1000B ... Alignment film processing device, 1011 ... Light source device, 1012 ... Polygon scanner, 1013 ... Mirror, 1014 ... Stage device, 1015 ... Control device, 1016 ... Polygon scanner, 1121 ... Rotating polygon mirror, 1122 ... Drive device, 1123 ... Rotation sensor, 1141... Stage, 1422 drive device, 1143. 61 ... Rotating polygon mirror, 1170 ... Optical system, 1171 ... Cylindrical lens, 1172 ... Cylindrical lens, 1173 ... Slit plate, 2000 ... Color printer (image forming apparatus), 2030a-2030d ... Photosensitive drum (image carrier), 2010 Optical scanning device, LU1, LU2, light source unit, 2101a, 2101b, transparent substrates (substrates), 2103a, 2103b, alignment film, 2104, nematic liquid crystal layer.

JP 2000-126202 A

Claims (8)

An alignment film processing apparatus for imparting alignment controllability for controlling the alignment direction of liquid crystal molecules in the liquid crystal layer to the alignment film used in contact with the liquid crystal layer,
A light source device for emitting ultraviolet light;
An optical device that reflects ultraviolet light from the light source device and irradiates the alignment film, and rotates the polarization direction of the ultraviolet light based on the alignment direction for each irradiation position of the ultraviolet light in the alignment film; With
Line connecting the irradiation position of the ultraviolet light in the alignment film you being a curve Oriented film processor. The alignment film according to claim 1 , wherein the optical device includes a reflecting member that rotates a polarization direction of the ultraviolet light based on the alignment direction for each irradiation position of the ultraviolet light in the alignment film. Processing equipment. The alignment film processing apparatus according to claim 2 , wherein the reflection member is a mirror having a curved reflection surface. The optical device according to claim 2, wherein the ultraviolet light from the light source device comprises a deflector for reflecting toward the reflective member, for scanning the alignment layer by the ultraviolet light reflected by the reflection member Or the alignment film processing apparatus of 3. The reflecting member is a deflector;
The alignment film processing apparatus according to claim 2 , wherein the alignment film is scanned by ultraviolet light deflected by the deflector. 6. The alignment film processing apparatus according to claim 5 , wherein the ultraviolet light from the light source device is obliquely incident on the deflector. The alignment film processing apparatus according to claim 4 , further comprising a control device that controls the light source device in synchronization with rotation or swinging of the deflector. The optical device according to claim 2, the ultraviolet light from the light source device, wherein the diverging light in the film parallel to the surface plane of the alignment film, characterized in that it comprises an optical system for emitting toward the reflective member Or the alignment film processing apparatus of 3.