JP2007193147A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To highly accurately transfer a toner image formed on a photoreceptor drum onto a glass substrate. <P>SOLUTION: The image forming apparatus 1 includes: a stage 21 that attractively holds the glass substrate 9 having a conductive layer 91 formed on a base thereof; and the photoreceptor drum 31 on which a pre-transfer toner image is formed. A prescribed potential is applied by a potential apply part 4 to the conductive layer 91, and the photoreceptor 312 is uniformly electrified by an auxiliary electrifier 35 just before a transfer position, and a transfer voltage works between the glass substrate 9 and the photoreceptor drum 31 at the transfer position. In this case, in a design, a gap is formed between the glass substrate 9 and the photoreceptor drum 31, and the glass substrate 9 is released from being attractively held near the transfer position, and the glass substrate 9 is flexed toward the photoreceptor drum 31 by an electric attraction force, consequently, the toner image and the glass substrate 9 can come in contact with each other without applying a mechanical pressure, then, the toner image is highly accurately transferred onto the glass substrate 9. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for forming a toner image on a plate-like or film-like object.

  2. Description of the Related Art Conventionally, as a method for transferring toner to a printing medium by an electrophotographic method, a method called corona transfer or roller transfer, in which toner is directly transferred to a printing medium using static charging, is known. Further, an intermediate transfer system in which toner is transferred from an image carrier to an intermediate transfer member and then transferred to a printing medium has been put into practical use. The intermediate transfer system has the feature that toner can be transferred to various types of transfer materials, similar to a printing apparatus that prints ink on a printing medium from a bracket roll, and uses an electrostatic field for primary transfer and secondary transfer. There are methods and primary transfer using an electrostatic field, and secondary transfer using adhesion, pressure and heat.

  On the other hand, a glass substrate of a color filter used for a printed circuit board or a liquid crystal display device is a plate-like insulator having a certain degree of rigidity, so that direct transfer is difficult. Even with the intermediate transfer method that uses pressure to transfer toner to the substrate, the transfer is performed twice and the mechanical accuracy of the device requires high-definition printed circuit boards and color filters. It becomes difficult to satisfy the accuracy and resolution to be achieved.

In Patent Document 1, when a liquid toner image formed on a photosensitive drum is directly transferred to a glass substrate, a gap is provided between the drum and the glass substrate, and the gap is filled with a carrier liquid of the liquid toner. Is disclosed.
JP-T-2002-527783

  By the way, although the glass substrate for a color filter has a high flat surface accuracy, there is a slight variation in thickness, and the entire substrate has waviness. In the apparatus of Patent Document 1, it has been confirmed that a high dimensional accuracy is actually required for the gap, and faithful transfer is performed where the gap between the drum and the glass substrate is small. If the gap is increased by a little due to the unevenness and undulation of the toner, the toner transfer accuracy is lowered. Also, variations in the thickness of the glass substrate and vibration of the shaft of the drum cannot be prevented even if the glass substrate is held by a highly rigid suction plate having a highly accurate plane, and there are several tens of micrometers in the gap. There will always be variations in the meter.

  In order to improve the adhesion between the drum and the glass substrate in the apparatus of Patent Document 1, it is conceivable to urge the glass substrate toward the drum using an elastic body. Only the part that has been crushed is crushed and the resolution is partially reduced.

  SUMMARY An advantage of some aspects of the invention is that a toner image is transferred onto an object with high accuracy from an annular member on which an untransferred toner image is formed on an outer peripheral surface.

  The invention according to claim 1 is an image forming apparatus for forming a toner image on a plate-like or film-like object, and is a cylindrical drum-like or flat belt on which an untransferred toner image is formed on an outer peripheral surface A toner image holding portion that circulates and moves a ring-shaped annular member along the outer peripheral surface, and a conductive or semiconductive conductive layer on one main surface of a conductive or semiconductive object or substrate. The object may be conveyed along a conveyance path facing the annular member, and the part of the object at a transfer position where the outer peripheral surface and the object are closest to each other may be bent toward the outer peripheral surface. In a possible state, a transport mechanism that moves in the same traveling direction at the same speed as the portion of the transfer position on the outer peripheral surface, and applies a predetermined potential to the conductive or semiconductive object or the conductive layer. The object A predetermined transfer voltage is applied between the portion of the transfer position and the portion of the outer peripheral surface, and the portion of the object is directed toward the annular member by an electric attractive force resulting from the transfer voltage. And a potential applying unit that transfers the toner image to the object while being bent.

  The invention according to claim 2 is the image forming apparatus according to claim 1, wherein the object is conductive or semiconductive on one main surface of a plate-like or film-like insulating substrate. A conductive layer is attached, and the conductive layer is located on the opposite side of the insulating base material from the annular member when the toner image is transferred.

  A third aspect of the present invention is the image forming apparatus according to the second aspect, wherein the potential applying unit applies a potential having a polarity opposite to a charging polarity of the toner image holding unit to the conductive layer. .

  According to a fourth aspect of the present invention, there is provided the image forming apparatus according to any one of the first to third aspects, wherein a latent image forming unit that forms an electrostatic latent image on the outer peripheral surface of the annular member, and toner A developing unit that develops the electrostatic latent image to form a toner image, and an auxiliary charge that is disposed between the transfer position and the developing unit and charges the annular member to a predetermined potential from above the toner image. And a vessel.

  A fifth aspect of the present invention is the image forming apparatus according to any one of the first to fourth aspects, wherein the amount of deflection of the portion of the object at the transfer position is set to 30 μm to 100 μm.

  A sixth aspect of the present invention is the image forming apparatus according to any one of the first to fifth aspects, wherein the transport mechanism is arranged in a transport direction of the target object on a holding surface on which the target object is placed. A plurality of adsorbing elements arranged to hold the object from the opposite side of the annular member; a moving mechanism for moving the holding unit along the transport path; and a plurality of adsorbing elements A suction control unit for releasing suction by the one located at the transfer position.

  The invention according to claim 7 is an image forming method for forming a toner image on a plate-like or film-like object, and a) a cylindrical drum-like or flat belt-like ring that circulates and moves along the outer peripheral surface. Forming a pre-transfer toner image on the outer peripheral surface of the member; and b) having a conductive or semiconductive conductive layer on one main surface of the conductive or semiconductive object or substrate. The object may be conveyed along a conveyance path facing the annular member, and the part of the object at a transfer position where the outer peripheral surface and the object are closest to each other may be bent toward the outer peripheral surface. In a possible state, the step of moving in the same traveling direction at the same speed as the portion of the transfer position on the outer peripheral surface, c) in parallel with the step b), a predetermined potential is set to the conductive or semiconductive To be applied to the object or the conductive layer Accordingly, a predetermined transfer voltage is applied between the part of the transfer position of the object and the part of the outer peripheral surface, and the part of the object is generated by an electric suction force caused by the transfer voltage. And transferring the toner image to the object while bending toward the annular member.

  The invention according to claim 8 is the image forming method according to claim 7, wherein the conductive layer is provided on one main surface of a plate-like or film-like insulating substrate before the step a). A step of pasting and preparing the object; and a step of separating the conductive layer from the object after the step c), and in the step c), the annular member of the insulating substrate. The conductive layer is located on the opposite side of the electrode.

  According to a ninth aspect of the present invention, in the image forming method according to the seventh or eighth aspect, the annular member is placed on the toner image from a predetermined position between the step a) and the step c). The method further includes a step of charging to a potential.

  A tenth aspect of the present invention is the image forming method according to any one of the seventh to ninth aspects, wherein in the step b), the object is conveyed on a holding surface on which the object is placed. The object is conveyed while being adsorbed and held from the opposite side to the annular member by a plurality of adsorbing elements arranged in a direction, and in the step c), the object located at the transfer position among the plural adsorbing elements Adsorption by is released.

  In the present invention, the toner image and the object are brought into contact (substantially) with an electric suction force, so that an unnecessarily strong force can be prevented from acting on the toner image. Thus, the toner image can be transferred.

  According to the second, third, and eighth aspects of the invention, it is possible to perform highly accurate transfer using an electrical attractive force even for an insulator on which a conductive layer cannot be formed on the main surface. In the inventions 9 and 9, since the annular member is uniformly charged before transfer, the force with which the annular member sucks the object at the transfer position becomes uniform, and the toner image can be transferred with higher accuracy.

  Further, in the invention of claim 5, it is possible to prevent the displacement of the object and to reduce the impact when the object contacts the toner image on the annular member. It is possible to bend only the portion of the transfer position of the object while maintaining the position accuracy on the holding surface of the object.

  FIG. 1 is a diagram showing a configuration of an image forming apparatus 1 according to the first embodiment of the present invention. The image forming apparatus 1 is a printing apparatus that forms an image of toner on a plate-like glass substrate 9 using electrophotography, and the toner image after printing is fixed on the glass substrate 9 by a heater 27 described later. Thus, a color filter for a flat display device such as a liquid crystal display device is manufactured. Actually, three image forming apparatuses 1 respectively corresponding to toners of three colors R (red), G (green), and B (blue) are arranged in a line, and the last image forming apparatus 1 has a fixing device. A blower 26 and a heater 27 are provided.

  The image forming apparatus 1 includes a transport mechanism 2 that transports the glass substrate 9 in the (+ Y) direction in FIG. 1 along a predetermined transport path, and a color of R, G, or B on the photosensitive drum by electrophotography. A process unit 3 for forming the toner image and a potential applying unit 4 in contact with the glass substrate 9. The glass substrate 9 is a substrate in which a transparent, conductive or semiconductive conductive layer 91 is uniformly formed on a main surface (upper surface) on the (+ Z) side in FIG. 1 of an insulating base material (glass). In this embodiment, an ITO (Indium Tin Oxide) film is used as the conductive layer 91. The potential applying unit 4 applies a predetermined potential to the conductive layer 91, and the process unit 3 is arranged on the conductive layer 91 side of the glass substrate 9.

  The thickness of the glass substrate 9 is typically 0.3 to 0.7 millimeter (mm), and the thickness of the conductive layer 91 is 0.5 to 1 micrometer (μm). A grid-like black matrix is further formed on the conductive layer 91. In FIG. 1, the conductive layer 91 and the black matrix on the substrate are represented by a single thick line.

  As shown in FIG. 1, the transport mechanism 2 includes a stage 21 that is a holding unit that holds the glass substrate 9 by suction, a moving mechanism 22 that is provided on the surface plate 11 and moves the stage 21 along the transport path, and A suction control unit 23 (see FIG. 2 described later) for controlling the suction holding of the glass substrate 9 by the stage 21 is provided.

  FIG. 2 is a plan view showing the stage 21 and the suction control unit 23. In FIG. 2, the glass substrate 9 is indicated by a two-dot chain line. As shown in FIGS. 1 and 2, the holding surface 210 on which the glass substrate 9 of the stage 21 is placed is a highly accurate plane, and each holding surface 210 is perpendicular to the conveyance direction of the glass substrate 9. Grooves 211 that are a plurality of suction elements that extend in the X direction and are arranged in the transport direction are formed. A plurality of tubes 212 are attached to the (+ X) side and the (−X) side of the stage 21, and each groove 211 is connected to the suction control unit 23 via the corresponding two tubes 212. It is connected to a decompression pump (not shown). In the stage 21, air is sucked from the plurality of grooves 211 by the decompression pump and the glass substrate 9 is sucked and held on the holding surface 210, and suction by each groove 211 can be individually turned on / off by the suction control unit 23. The Actually, the tube 212 is bundled and bent sufficiently long so as not to hinder the movement of the stage 21.

  FIG. 3 is a side view showing the configuration of the moving mechanism 22 and shows a state viewed from the (−Y) side in FIG. 1 toward the (+ Y) direction. The moving mechanism 22 has a pair of guide rails 231 each extending in the Y direction on the surface plate 11, and the stage 21 is provided with a slider 232 at a position facing each guide rail 231. Each slider 232 is supplied with high-pressure air from an air supply unit 233, and the slider 232 engages the guide rail 231 in a non-contact manner, and the stage 21 is supported so as to be movable in the Y direction. The moving mechanism 22 further includes a linear motor 24, the fixed body 241 of the linear motor 24 is fixed on the surface plate 11, and the moving body 242 is attached to the stage 21. Then, by driving the linear motor 24, the stage 21 moves smoothly in the Y direction.

  As shown in FIG. 1, the process unit 3 includes a photosensitive drum 31 having a diameter of 250 mm connected to a motor (not shown) via a speed reducer, and the photosensitive drum 31 is a rotating shaft parallel to the X direction in FIG. It is supported so as to be rotatable about J1. The photosensitive drum 31 includes a drum body 311 that is formed of a metal such as aluminum and that has a rotation axis J1 as the center. The drum body 311 is electrically grounded. On the outer peripheral surface of the drum body 311, for example, a single layer type organic photoreceptor having a phthalocyanine pigment (hereinafter simply referred to as “photoreceptor 312”) is uniformly applied (or deposited). The diameter of the photosensitive drum 31 is not limited to 250 mm, but is preferably 200 mm or more and 400 mm or less. Further, the photoconductor 312 may be formed of an inorganic photoconductor such as amorphous silicon in addition to the single layer type organic photoconductor having a phthalocyanine pigment.

  The process unit 3 further includes a main charger 32 provided to face the photosensitive drum 31, and the main charger 32 generates ions to charge the photoreceptor 312. A latent image forming unit that emits image forming light from the main charger 32 along the rotation direction 71 of the photosensitive drum 31 around the photosensitive drum 31 to form an electrostatic latent image on the outer peripheral surface of the photosensitive member 312. 33, a developing unit 34 that forms a toner image by developing the electrostatic latent image on the photoreceptor 312 with liquid toner (for example, wet toner dispersed in an isoparaffin-based insulating solvent (carrier liquid)), toner An auxiliary charger 35 that charges the photoconductor 312 to a predetermined potential from above the image, a cleaner 36 that cleans the surface of the photoconductor 312, and a static eliminator 37 that discharges light to neutralize the photoconductor 312 are disposed. . The developing unit 34 is connected to a toner supply unit (not shown) that supplies liquid toner as a developing solution.

  Further, the upper surface of the glass substrate 9 that moves along the conveyance path facing the photosensitive drum 31 is closest to the outer peripheral surface of the photosensitive drum 31 between the auxiliary charger 35 and the cleaner 36. As will be described later, the toner on the outer peripheral surface of the photosensitive drum 31 is transferred onto the glass substrate 9 at a position where the photosensitive drum 31 and the glass substrate 9 are closest to each other. A position where the outer peripheral surface and the glass substrate 9 (or the conductive layer 91) are closest to each other is referred to as a transfer position. The transfer position is a position fixed relative to the process unit 3.

  The potential applying unit 4 includes two contacts 41 arranged on the (+ Y) side and the (−Y) side of the transfer position, and the contacts 41 are brushes (carbon brush, A conductive bristle brush or the like). As shown in FIG. 2, the (+ Y) side and (−Y) side contacts 41 are disposed on the (−X) side of the stage 21, and each contact 41 is supported by a support member (not shown). . The contact 41 is in direct contact with the conductive layer 91 formed on the entire upper surface of the glass substrate 9. Actually, since the glass substrate 9 moves from the (−Y) side in FIG. 2 toward the (+ Y) direction, while the (+ Y) side end of the glass substrate 9 is positioned at the transfer position (− While the (Y) contact 41 is in contact with the conductive layer 91 of the glass substrate 9 and the (−Y) side end of the glass substrate 9 is located at the transfer position, the (+ Y) contact 41 is the glass substrate. 9 at the time of toner transfer, at least one of the (+ Y) side and (−Y) side contacts 41 is always in contact with the conductive layer 91. As shown in FIG. 1, a transfer voltage supply source 42 is connected to the electrode of each contact 41, and a predetermined potential is applied to the conductive layer 91 of the glass substrate 9 through the contact 41.

  In the image forming apparatus 1, when the entire glass substrate 9 is attracted to the stage 21, 30 μm to 100 μm (preferably between the outer peripheral surface of the photoconductor 312 and the conductive layer 91 of the glass substrate 9 at the transfer position). The photosensitive drum 31 and the stage 21 are positioned so that a design gap of 40 μm to 80 μm is generated. As will be described later, when the toner image is transferred, the adsorption by the stage 21 is partially released, and the glass substrate 9 is electrically drawn to the photosensitive drum 31 as shown in FIG. The part bends by 30 μm to 100 μm (preferably 40 μm to 80 μm). In the present embodiment, the amount of bending of the glass substrate 9 is set to 50 μm, and in FIG. 1, the amount of bending of the glass substrate 9 is greatly illustrated (the same applies to FIGS. 6 and 9 described later).

  FIG. 4 is a diagram illustrating a flow of processing in which the image forming apparatus 1 forms a toner image on the glass substrate 9. Note that steps S14 to S18 in FIG. 4 show the flow of processing focusing on a part of the photoconductor 312, and these steps are actually substantially parallel in time to the entire photoconductor 312. Done.

  In the image forming apparatus 1 of FIG. 1, first, a glass substrate 9 on which a conductive layer 91 and a black matrix are formed in advance on a base material is placed on a stage 21 by an external device, and the lower surface is sucked (step S11). ). As a result, the glass substrate 9 is held from the side opposite to the photosensitive drum 31. Subsequently, the photosensitive drum 31 starts rotating at a constant rotational speed in the predetermined rotational direction 71 around the rotational axis J1, and the glass substrate 9 also moves at a constant speed in the (+ Y) direction together with the stage 21. Start (steps S12 and S13). In the process unit 3, by rotating the photosensitive drum 31, each photosensitive drum 31 that is a cylindrical drum-shaped annular member centered on the rotation axis J1 is arranged around the outer peripheral surface. Device 32, latent image forming unit 33, developing unit 34, auxiliary charger 35, cleaner 36, and static eliminator 37) are continuously circulated to start processing on photoconductor 312 with these peripheral configurations.

  In the main charger 32, electric charges are sequentially applied to a part of the photoreceptor 312 (hereinafter referred to as “target part”) that reaches the facing position, and the surface of the target part is, for example, (+700) volts (V ) To uniformly charge (step S14). The charged target portion continuously moves to the light irradiation position of the latent image forming unit 33. The latent image forming unit 33 includes a light source in which a plurality of light emitting diodes (LEDs) that emit light having a predetermined wavelength are arranged (LED array). Of the image data of each color component generated from the image showing the color filter pattern, image data corresponding to the toner color of the process unit 3 is input to the latent image forming unit 33, and the image data corresponding to the image data is input. The forming light is emitted toward the photoconductor 312. The portion of the target portion of the photoconductor 312 that is irradiated with light is removed by moving the surface charge into the photoconductor 312. In addition, since the charged state is maintained as it is in the portion that is not irradiated with light, an image (that is, an electrostatic latent image) is formed on the surface of the photoreceptor 312 based on the distribution of charges (step S15). The light source of the latent image forming unit 33 is not necessarily an LED, and may be, for example, a semiconductor laser or a combination of a lamp and a liquid crystal shutter.

  The portion (target portion) where the electrostatic latent image is formed on the photosensitive drum 31 moves to a position facing the developing portion 34, and is dispersed and charged in the liquid toner (solvent in the solvent) by the developing roller 341 of the developing portion 34. Toner) is applied to the electrostatic latent image (step S16). At this time, the positively charged toner having the same polarity as the surface of the photoconductor 312 adheres only to the portion of the photoconductor 312 where the charge has been removed, and the electrostatic latent image is developed. That is, a toner image before transfer is formed on a target portion on the outer peripheral surface of the photoreceptor 312, and the process unit 3 including the photosensitive drum 31 and the drum rotating motor serves as a toner image holding unit that holds the toner image. Yes. Unnecessary liquid toner on the target site is scraped off by the squeegee roller 342 on the downstream side of the developing unit 34 and returned to the developing unit 34. Here, for example, a potential of (+500) volts (V) is applied to the developing roller 341 and the squeegee roller 342 by the developing bias power source 343 in order to charge the toner. Note that the potential of the developing unit 34 and the photosensitive drum 31 may be adjusted so that the charged toner adheres to the charged portion on the photoconductor 312.

  Next, the photoconductor 312 is charged from above the developed toner image by the auxiliary charger 35 to a predetermined potential having the same polarity as the charging polarity of the liquid toner, for example, (+700) volts (V) (step S17). The auxiliary charger 35 has the same structure as the main electric appliance 32. Thereafter, the target portion reaches a transfer position that is closest to the upper surface of the glass substrate 9 that moves in synchronization with the rotation of the photosensitive drum 31, and the target portion is at a speed (in accordance with the rotational speed of the photosensitive drum 31). That is, it moves accurately in the (+ Y) direction at a tangential speed in a cross section perpendicular to the rotation axis J1 of the outer peripheral surface of the photosensitive drum 31.

  FIG. A and FIG. FIG. 7B is a diagram for explaining a state of toner transfer in the image forming apparatus 1. In addition, FIG. A and FIG. In B, toner particles are indicated by circles with “+” inside, and the presence of the black matrix is ignored. Further, as in FIG. 1, the bending of the glass substrate 9 at the time of transfer is greatly illustrated, and the carrier liquid is actually filled between the photosensitive drum 31 and the glass substrate 9 (see FIG. 8 described later). Same as in A and FIG. 8.B).

  The glass substrate 9 is held by suction on the stage 21 and is transported by the transport mechanism 2 at the same speed as the target portion of the photoconductor 312 at the transfer position, with the same (+ Y) direction as the traveling direction of the target portion being the traveling direction. Is done. Thereby, the position of the glass substrate 9 (part facing the target part) is fixed relatively to the target part in the very vicinity of the transfer position.

  At this time, in parallel with the movement of the glass substrate 9, a predetermined potential, for example, a potential of (-100) volts (V) is applied to the conductive layer 91 of the glass substrate 9 by the transfer voltage supply source 42. A transfer voltage acts between the conductive layer 91 of the glass substrate 9 and the target portion of the photoreceptor 312 at the position. That is, an electric field from the target portion toward the conductive layer 91 is generated, and a force toward the conductive layer 91 acts on the toner.

  In the image forming apparatus 1, the suction control unit 23 (see FIG. 2) is controlled in accordance with the movement of the photoconductor 312 indicated by the arrow 71 and the movement of the glass substrate 9 indicated by the arrow 72. Of the plurality of grooves 211, the adsorption by the grooves 211 located at the transfer position (more precisely, the plurality of grooves 211 located within a certain distance in the (± Y) direction from the transfer position) is sequentially released, and the glass substrate 9 is a state where the transfer position portion 9 can be bent toward the outer peripheral surface of the photosensitive drum 31. As a result, FIG. As shown in A, the transfer position of the glass substrate 9 is deflected toward the photosensitive drum 31 by the electric attractive force resulting from the transfer voltage, and the conductive layer 91 and the photosensitive member 312 of the glass substrate 9 are in close contact with the toner interposed therebetween. To do. In the suction control unit 23, in order to perform partial release of suction at high speed, blow may be instantaneously performed in the groove 112 for releasing suction.

  Then, the transfer position portion of the glass substrate 9 moves in the same advancing direction at the same speed as the transfer position portion of the outer peripheral surface of the photosensitive drum 31, FIG. As shown in B, the positively charged toner image on the target portion of the photoreceptor 312 is sequentially transferred to the conductive layer 91 of the glass substrate 9 (step S18). Note that the portion of the glass substrate 9 that has passed the transfer position is again sucked and held by the groove 211 of the stage 21. Accordingly, it is possible to bend only the portion of the glass substrate 9 at the transfer position while maintaining the positional accuracy of the glass substrate 9 on the holding surface 210.

  The target portion of the photosensitive member 312 after the transfer of the toner continues to move to the position of the cleaner 36 shown in FIG. 1, and the toner remaining on the target portion by the cleaner 36 (that is, the toner that has not been transferred to the glass substrate 9). The surface of the photoconductor 312 is cleaned by removing unnecessary materials such as the photoconductor 312 and the photoconductor 312 is mechanically returned to the initial state. Then, light is irradiated by a combination of a lamp and a filter, or a static eliminator 37 having an LED or the like, so that the photosensitive member 312 is neutralized and is electrically returned to an initial state.

  The processes in steps S14 to S18 are performed almost in parallel with each part on the photoconductor 312, and the process is continuously performed on each part of the photoconductor 312 that sequentially reaches the transfer position. Specifically, the entire toner image on the outer peripheral surface of the photoreceptor 312 is transferred onto the glass substrate 9 at the transfer position. When the transfer to the entire glass substrate 9 is completed, excess carrier liquid on the glass substrate 9 is air-dried by the blower 26 (step S19), heated and melted by the heater 27, and the toner is transferred to the glass substrate 9. Is fixed (step S20). Finally, the rotation of the photosensitive drum 31 is stopped, the transport mechanism 2 is stopped, and the printing process by the image forming apparatus 1 is finished (steps S21 and S22). As a result, a toner image of one color is formed on the entire glass substrate 9.

  Actually, the photosensitive drum 31 rotates a plurality of times, and toner images are transferred onto the plurality of glass substrates 9 continuously. Further, as described above, when three image forming apparatuses 1 corresponding to the respective colors of R, G, and B are prepared and a toner image of one color is formed on the glass substrate 9, fixing is performed. The glass substrate 9 is conveyed to the next image forming apparatus 1 without being formed, and a toner image of the next color is formed. As a result, toner images of R, G, and B colors are formed on the glass substrate 9 by the three image forming apparatuses 1 and are fixed in the last image forming apparatus 1 to complete a color filter. Note that the fixing process may be performed individually in each image forming apparatus 1.

  As described above, in the image forming apparatus 1, a predetermined transfer voltage is applied between the transfer position portion of the glass substrate 9 and the target portion of the photoconductor 312 in parallel with the conveyance process of the glass substrate 9. In addition, the toner image is transferred while the glass substrate 9 is bent toward the photoconductor 312 side by the electric attractive force resulting from the transfer voltage. As a result, the toner image and the glass substrate 9 are brought into contact with each other by an electric suction force without applying mechanical pressure (or substantially contacted to such an extent that the toner image can be regarded as being substantially in contact). The toner image and the glass substrate 9 can be brought into contact with each other with a magnitude of a force capable of preventing the influence of the undulation of the glass substrate 9 while preventing an unnecessarily strong force from acting on the image. A toner image can be transferred with high accuracy.

  The image forming apparatus 1 is designed so that a gap of 30 μm to 100 μm is generated between the outer peripheral surface of the photoreceptor 312 and the conductive layer 91 of the glass substrate 9 at the transfer position when it is assumed that the glass substrate 9 is not bent. Is done. As a result, the amount of bending at the transfer position of the glass substrate 9 is set to 30 μm to 100 μm, and the glass substrate 9 is prevented from being displaced by suppressing excessive bending of the glass substrate 9, and the glass substrate 9 The impact when contacting the toner image on the photoreceptor 312 can be reduced. Further, since the auxiliary charger 35 is disposed between the transfer position and the developing unit 34, the photosensitive member 312 is uniformly charged by the auxiliary charger 35 regardless of the presence or absence of toner adhesion before transfer. The attracting force between the photoconductor 312 and the glass substrate 9 at the position becomes uniform in the width direction (X direction) of the glass substrate 9, and the toner image can be transferred with higher accuracy. In the case of the image forming apparatus 1, the magnitude of the force with which the photoreceptor 312 pulls the glass substrate 9 is several tens of grams with respect to the width of 1 cm in the X direction, excluding the weight of the glass substrate 9.

  FIG. 6 is a diagram showing an image forming apparatus 1a according to the second embodiment of the present invention. The image forming apparatus 1a includes a stage 21a and a potential applying unit 4a that are different in structure from the stage 21 and the potential applying unit 4 of the image forming apparatus 1 shown in FIG. 1, and other components are the same as those of the image forming apparatus 1 of FIG. These are the same and are given the same reference numerals. In the image forming apparatus 1a, a glass substrate 9 (first film) in which a conductive polyimide sheet (hereinafter referred to as “conductive layer”) 91a is an insulating base material on the main surface (lower surface) on the (−Z) side in FIG. Unlike the glass substrate of the embodiment, an ITO film is not formed.) A toner image is formed on a substrate 9a (hereinafter referred to as “target substrate”) 9a. That is, in the first embodiment, the glass substrate 9 having the conductive layer 91 is an object to which toner is transferred. In the second embodiment, the conductive layer 91a is bonded to the glass substrate 9 which is a base material. The conductive layer 91a is located on the opposite side of the glass substrate 9 from the photosensitive drum 31. As the conductive layer 91a, specifically, a conductive polyimide sheet having a volume resistance value of 100 Ω · cm and a thickness of 0.1 mm is used. However, the conductive layer 91a is a conductive or semiconductive conductive layer 91a. If present, another conductive sheet may be used.

  The stage 21a has an upper electrode 213 that is long in the transport direction (Y direction) of the target substrate 9a on the holding surface 210, and a lower electrode 214 that is long in the transport direction on the lower surface. The upper electrode 213 and the lower electrode 214 are electrically connected. When the toner image is transferred, the contact 41 of the potential applying unit 4a contacts the lower electrode 214, and the transfer voltage supply source 42 becomes the lower electrode 214. When a predetermined potential is applied, a potential is applied to the conductive layer 91a via the upper electrode 213, and a transfer voltage is applied between the photosensitive drum 31 and the conductive layer 91a. The other structure of the stage 21a is the same as that of FIG. 2, and a plurality of grooves 211 are arranged on the holding surface 210 along the transport direction of the target substrate 9a.

  FIG. 7 is a diagram showing a flow of processing in which the image forming apparatus 1a forms a toner image on the target substrate 9a. When the image forming apparatus 1a forms a toner image on the target substrate 9a, first, the conductive layer 91a is attached to the lower surface of the glass substrate 9 to prepare the target substrate 9a (step S31). The conductive layer 91a may be pasted using an adhesive, or may be so-called water pasted using a liquid such as water, alcohol, or a carrier liquid of liquid toner. Note that by using a liquid that may remain on the target substrate 9a, the conductive layer 91a can be easily peeled off in a later step.

  When the conductive layer 91a is affixed to the glass substrate 9, the target substrate 9a is placed on the stage 21a and sucked and held, as in the image forming apparatus 1 of FIG. 1 (FIG. 4: step S11). Subsequently, after the rotation of the photosensitive drum 31 and the movement of the target substrate 9a by the moving mechanism 22 are started (steps S12 and S13), the photosensitive member 312 is charged by the main charger 32 (step S14), and an electrostatic latent image is formed. (Step S15), development of the electrostatic latent image (Step S16) is sequentially performed on the target portion of the photoreceptor 312, and the target portion is uniformly made up to a predetermined potential from the formed toner image by the auxiliary charger 35. Charged (step S17). Thereafter, the target part moves to the transfer position.

  FIG. A and FIG. FIG. 7B is a diagram illustrating a state when toner is transferred in the image forming apparatus 1a. As described above, the conductive layer 91a of the target substrate 9a is given a predetermined potential having a polarity opposite to the charging polarity of the photoreceptor 312 by the transfer voltage supply source 42, for example, a potential of (−2000) volts (V). Thus, a transfer voltage acts between the conductive layer 91a of the target substrate 9a and the target portion of the photoconductor 312 at the transfer position. That is, an electric field from the target portion toward the glass substrate 9 is generated, and a force toward the glass substrate 9 acts on the toner.

  In the image forming apparatus 1a, as in the image forming apparatus 1 of FIG. 1, the suction control unit 23 (see FIG. 2) is accompanied by the movement of the photosensitive drum 31 indicated by the arrow 71 and the movement of the target substrate 9a indicated by the arrow 72. ) Is sequentially released from the plurality of grooves 211 of the stage 21 a by the grooves 211 positioned at the transfer position, and the transfer position portion of the target substrate 9 a is directed toward the outer peripheral surface of the photosensitive drum 31. It is in a state where it can bend. As a result, FIG. As shown in A, the portion of the transfer position of the target substrate 9a is bent by 30 μm to 100 μm (preferably 40 μm to 80 μm) toward the outer peripheral surface of the photosensitive drum 31 by the electric attractive force caused by the transfer voltage, and the target substrate 9a The (glass substrate 9) and the outer peripheral surface of the photosensitive drum 31 are in close contact with the toner interposed therebetween.

  Then, the transfer position portion of the target substrate 9a moves in the same traveling direction at the same speed as the transfer position portion of the outer peripheral surface of the photosensitive drum 31, and thus, FIG. As shown in B, the toner images are sequentially transferred onto the target substrate 9a (step S18). In addition, since the target substrate 9a is sucked and held on the stage 21 at a position other than the transfer position, only the portion of the target substrate 9a at the transfer position can be bent while maintaining the positional accuracy on the holding surface 210 of the target substrate 9a.

  Thereafter, the target portion of the photoreceptor 312 is mechanically and electrically returned to the initial state by the cleaner 36 and the static eliminator 37.

  When the entire toner image on the photoconductor 312 is transferred onto the target substrate 9a, the toner is air-dried by the blower 26 (step S19), and the toner is fixed to the glass substrate 9 by the heater 27 (step S20). When the rotation of the photosensitive drum 31 and the movement of the target substrate 9a are stopped (Steps S21 and S22), the target substrate 9a is taken out from the image forming apparatus 1a and the conductive layer 91a is peeled from the target substrate 9a (FIG. 7: Step S32). Then, the glass substrate 9 for the flat display device on which the toner is fixed is obtained. When an adhesive is used for bonding the conductive layer 91a to the glass substrate 9, the conductive layer 91a is peeled off together with the adhesive.

  In the image forming apparatus 1 a, the conductive layer 91 a is attached to the lower surface of the glass substrate 9, so that an insulator such as a glass substrate on which the conductive layer cannot be formed on the upper surface is the same as in the image forming apparatus 1. By using the electric suction force to bring the photosensitive drum 31 and the target substrate 9a into contact with each other with an appropriate force, highly accurate transfer can be performed.

  FIG. 9 is a diagram illustrating a configuration of an image forming apparatus 1b according to the third embodiment. In the image forming apparatus 1b, an intermediate transfer unit 25 having an intermediate transfer body 251 is provided, and the toner image on the photosensitive drum 31 is indirectly transferred onto the glass substrate 9 via the intermediate transfer body 251. The intermediate transfer body 251 is a flat belt-like annular member formed of a dielectric material, and is provided so as to circumscribe the two rollers 252a and 252b. A motor is connected to one of the rollers 252a, and when the motor is driven, the intermediate transfer member 251 circulates and moves along the outer peripheral surface while being in contact with the toner image on the photosensitive drum 31. A DC power supply 253 is connected to the other roller 252b. As in the case of FIG. 1, the glass substrate 9 has a conductive layer 91 formed on the upper surface. Further, as compared with the image forming apparatus 1 of FIG. 1, the auxiliary charger 35 is provided immediately before the transfer position of the intermediate transfer member 251, and the moving direction of the glass substrate 9 along the conveyance path facing the intermediate transfer member 251 is changed. It is further different in that it is in the opposite direction ((−Y) direction). Other components are the same as those in FIG. 1, and the same components are denoted by the same reference numerals.

  In the image forming apparatus 1b, the toner image formed on the photosensitive member 312 by the main charger 32, the latent image forming unit 33, the developing unit 34, and the like is applied to the intermediate transfer member 251 via the roller 252b. Transferred onto the intermediate transfer member 251. That is, the intermediate transfer unit 25 including the intermediate transfer member 251 and a mechanism for circulating and moving the intermediate transfer member 251 indirectly forms a toner image before transfer on the outer peripheral surface of the intermediate transfer member 251 and holds the toner image. Has become a department. Immediately before the transfer position where the outer peripheral surface of the intermediate transfer body 251 and the glass substrate 9 are closest to each other, a predetermined potential is uniformly applied to the intermediate transfer body 251 by the auxiliary charger 35, and the portion to which the potential is applied is electrically conductive. It is sent toward the glass substrate 9 on which the layer 91 is formed.

  Similarly to the image forming apparatus 1 of FIG. 1, by partially releasing the suction by the stage 21, the transfer position portion of the glass substrate 9 can be bent toward the outer peripheral surface of the photosensitive drum 31. Furthermore, the transfer position portion of the glass substrate 9 moves in the same traveling direction at the same speed as the transfer position portion of the intermediate transfer body 251. At this time, since a predetermined potential is applied to the conductive layer 91 of the glass substrate 9 by the potential applying unit 4, an electrical force directed to the glass substrate 9 acts on the toner at the transfer position, and an electrical attractive force. As a result, the glass substrate 9 bends toward the intermediate transfer member 251, and the toner image on the intermediate transfer member 251 adheres to the glass substrate 9 while the intermediate transfer member 251 and the glass substrate 9 are brought into close contact with each other as in the first embodiment. Is transferred with high accuracy.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made.

  For example, instead of the photosensitive drum 31 in the first and second embodiments, a flat belt-shaped photosensitive belt may be used, and in the third embodiment, the intermediate transfer member 251 may be formed in a drum shape. .

  In the above embodiment, the polarity of the potential applied to the photosensitive drum 31 and the intermediate transfer member 251 is different from the polarity applied to the conductive layer. However, if the potential difference is sufficient, the polarity may be the same. Good. However, in the second embodiment, since the conductive layer 91a and the outer peripheral surface of the photosensitive drum 31 are separated from each other, it is preferable that they have different polarities in order to obtain a sufficient suction force. If the photosensitive drum 31 and the intermediate transfer member 251 are sufficiently charged without using the auxiliary charger 35, the auxiliary charger 35 may be omitted.

  In the image forming apparatus, the contacts of the potential applying units 4 and 4a for applying a potential to the conductive layers 91 and 91a apply a potential to the conductive layer using, for example, a spring material or a potential applying roller in addition to the brush. There may be. Further, in the image forming apparatus 1, if a transfer voltage acts between the photosensitive drum 31 or the outer peripheral surface of the intermediate transfer body 251 and the conductive layers 91 and 91a at the transfer position, the transfer voltage is applied to the conductive layers 91 and 91a. The potential may be a ground potential. In this case, the number of power supplies can be reduced.

  The holding of the glass substrate 9 (or the target substrate 9a) by the holding surface 210 of the stage 21 is not limited to vacuum suction, and may be held mechanically, for example. The toner used by the image forming apparatus is not limited to liquid toner, and may be dry toner.

  In the third embodiment, the toner image may be transferred to the target substrate 9a to which the conductive layer 91a is attached as in the second embodiment. Further, the conductive layer 91a attached to the glass substrate 9 may be an aluminum foil or the like other than the conductive polyimide sheet.

  In the image forming apparatus, the toner image can be efficiently and accurately transferred onto the glass substrate 9 to easily manufacture a high-accuracy color filter. However, the toner image is formed on a film-like transparent object. May be transferred to produce a color filter. In addition, the image forming apparatus may be used for applications other than the manufacture of color filters. A plate-like or film-like object to which a toner image is transferred in the image forming apparatus may be a printed wiring board such as a resin or ceramic. A conductive or semiconductive conductive layer may be formed on the main surface of the insulating base. In addition, the object itself may be conductive or semiconductive, such as a metal plate or a semiconductor substrate. In this case, it is not necessary to provide a conductive layer on the object, and the potential applying unit 4 may A potential is directly applied to the object.

1 is a diagram illustrating an image forming apparatus according to a first embodiment. It is a top view which shows a stage and a suction control part. It is a figure which shows a moving mechanism. It is a figure which shows the flow of the process which forms a toner image on a glass substrate. FIG. 6 is a diagram illustrating a state when toner is transferred. FIG. 6 is a diagram illustrating a state when toner is transferred. It is a figure which shows the image forming apparatus which concerns on 2nd Embodiment. It is a figure which shows the flow of the process which forms a toner image on a glass substrate. FIG. 6 is a diagram illustrating a state when toner is transferred. FIG. 6 is a diagram illustrating a state when toner is transferred. It is a figure which shows the image forming apparatus which concerns on 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a, 1b Image forming apparatus 2 Conveyance mechanism 3 Process unit 4, 4a Electric potential provision part 9 Glass substrate 9a Target board | substrate 21, 21a Stage 22 Movement mechanism 23 Adsorption control part 25 Intermediate transfer part 31 Photosensitive drum 33 Latent image formation part 34 Developing section 35 Auxiliary charger 91, 91a Conductive layer 210 Holding surface 211 Groove 251 Intermediate transfer body 312 Photoconductor S12 to S18, S31, S32 Steps

Claims (10)

An image forming apparatus for forming a toner image on a plate-like or film-like object,
A toner image holding unit that circulates and moves along a cylindrical drum-like or flat belt-like annular member on which a toner image before transfer is formed on the outer peripheral surface;
A conductive or semiconductive object or an object having a conductive or semiconductive conductive layer on one main surface of a substrate is conveyed along a conveyance path facing the annular member, and the outer circumference The part of the object at the transfer position where the surface and the object are closest to each other is the same at the same speed as the part of the transfer position on the outer peripheral surface in a state where the part can be bent toward the outer peripheral surface. A transport mechanism that moves in the direction of travel;
By applying a predetermined potential to the conductive or semiconductive object or the conductive layer, a predetermined transfer voltage is applied between the part of the transfer position of the object and the part of the outer peripheral surface. And a potential applying unit that transfers the toner image to the object while bending the portion of the object toward the annular member by an electric suction force caused by the transfer voltage,
An image forming apparatus comprising: The image forming apparatus according to claim 1,
The object is one in which a conductive or semiconductive conductive layer is attached to one main surface of a plate-like or film-like insulating substrate,
An image forming apparatus, wherein the conductive layer is positioned on a side opposite to the annular member of the insulating base material when a toner image is transferred. The image forming apparatus according to claim 2,
The image forming apparatus, wherein the potential applying unit applies a potential having a polarity opposite to a charging polarity of the toner image holding unit to the conductive layer. The image forming apparatus according to any one of claims 1 to 3,
A latent image forming unit that forms an electrostatic latent image on the outer peripheral surface of the annular member;
A developing unit for developing the electrostatic latent image with toner to form a toner image;
An auxiliary charger that is disposed between the transfer position and the developing unit and charges the annular member from above the toner image to a predetermined potential;
An image forming apparatus further comprising: The image forming apparatus according to any one of claims 1 to 4,
An image forming apparatus, wherein an amount of bending of the portion of the object at the transfer position is set to 30 μm to 100 μm. The image forming apparatus according to claim 1,
The transport mechanism is
A holding unit that holds the object from the opposite side to the annular member by a plurality of suction elements arranged in the conveyance direction of the object on a holding surface on which the object is placed;
A moving mechanism for moving the holding unit along the transport path;
An adsorption control unit for releasing adsorption by an element located at the transfer position among the plurality of adsorption elements;
An image forming apparatus comprising: An image forming method for forming a toner image on a plate-like or film-like object,
a) forming a toner image before transfer on the outer peripheral surface of a cylindrical drum-shaped or flat belt-shaped annular member that circulates and moves along the outer peripheral surface;
b) Conveying a conductive or semiconductive object or an object having a conductive or semiconductive conductive layer on one main surface of a substrate along a conveyance path facing the annular member; The part of the object at the transfer position where the outer peripheral surface and the object are closest to each other can be bent toward the outer peripheral surface at the same speed as the part of the transfer position on the outer peripheral surface. Moving in the same direction of travel,
c) In parallel with the step b), by applying a predetermined potential to the conductive or semiconductive object or the conductive layer, the portion of the transfer position of the object and the outer peripheral surface A predetermined transfer voltage is applied between the region and the toner image on the object while the region of the object is bent toward the annular member by an electric suction force caused by the transfer voltage. And the process of transferring to
An image forming method comprising: The image forming method according to claim 7,
Before the step a), preparing the object by attaching the conductive layer to one main surface of a plate-like or film-like insulating base;
After the step c), peeling the conductive layer from the object;
Further comprising
In the step c), the conductive layer is located on the opposite side of the insulating base material from the annular member. The image forming method according to claim 7 or 8, wherein
An image forming method, further comprising a step of charging the annular member from above the toner image to a predetermined potential between the step a) and the step c). The image forming method according to claim 7, wherein:
In the step b), the object is sucked and held from the side opposite to the annular member by the plurality of suction elements arranged in the transport direction of the object on the holding surface on which the object is placed. Conveyed,
In the step c), the image forming method is characterized in that adsorption by an element located at the transfer position among the plurality of adsorption elements is released.

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