JP2023048005A - Image reading apparatus - Google Patents

Abstract

To provide a technique capable of preventing a reduction in the reading accuracy of an image on a recording medium by holding the recording medium.SOLUTION: An image reading device includes reading means for reading an image formed on a recording medium, a transmitting member arranged between the recording medium and the reading means, pressing means opposing the transmitting member and pressing the recording medium against the transmitting member, and a pressure adjusting member arranged on the outer area of a reading area of the reading means, which is an area overlapping with the recording medium, for adjusting the pressing pressure by the pressing means to act higher on the recording medium in the outer area than in the reading area.SELECTED DRAWING: Figure 13

Description

The present invention relates to an image reading device.

Conventionally, when scanning transparencies or images formed on glossy paper with an image reading device that can read recording media using a lens with a shallow depth of field, the recording media must be placed on the platen glass. Reading was performed by bringing them in close contact.

Further, among image forming apparatuses for forming an image on a recording medium, there is an apparatus configured to first form an image on an intermediate transfer member such as an intermediate drum, and then transfer the image to the recording medium to record the image. be. In the apparatus having such a configuration, various processes are performed to improve the quality of formed images.

For example, in the image forming apparatus disclosed in Cited Document 1, a patch image formed on a recording medium is inspected by a reading device arranged downstream of the apparatus, and information is fed back to the image forming apparatus to obtain a formed image. quality improvement. Further, in order to perform highly accurate inspection, the sheet conveyed with the leading edge held is once stopped and pressed against the reading surface for reading, thereby stabilizing the reading state of the sheet.

JP 2018-133742 A JP 2006-166335 A

However, in the above-described conventional image reading configuration, since the platen glass and the recording medium are in close contact with each other, interference fringes occur between the platen glass and the transparent original or glossy paper. There was a problem that there was no For this reason, for example, in the image reading apparatus disclosed in Cited Document 2, the document is attached to the film holder and the glass and the recording medium are not brought into close contact with each other in the reading area to prevent the generation of interference fringes and read the image. there is

However, in the above-described conventional image reading configuration, the image floats on the glass and the distance between the paper and the lens varies greatly. In performing high-precision reading, there is a problem that the reading accuracy becomes insufficient. Further, in a configuration for reading a sheet conveyed by holding the leading edge as disclosed in Cited Document 1, holding the sheet with a film holder poses a problem of complicating the configuration and process of the apparatus.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique capable of preventing deterioration in reading accuracy of an image on a recording medium by holding the recording medium.

In order to solve the above-described problems, an image reading device according to the present invention includes:
reading means for reading an image formed on a recording medium;
a transmissive member disposed between the recording medium and the reading means;
pressing means that faces the transmission member and presses the recording medium against the transmission member;
a pressure adjusting member disposed in an area outside the reading area of the reading means and overlapping the recording medium, and for applying a higher pressing force by the pressing means to the recording medium in the outer area than in the reading area;
characterized by comprising

According to the present invention, it is possible to provide a technique capable of preventing deterioration in reading accuracy of an image on a recording medium by holding the recording medium.

Schematic diagram of a recording system that is a representative embodiment of the present invention Perspective view of recording unit Explanatory diagram showing the displacement of the recording unit in FIG. Block diagram of the control system of the recording system in FIG. Block diagram of the control system of the recording system in FIG. Explanatory diagram of an operation example of the recording system in FIG. Explanatory diagram of an operation example of the recording system in FIG. A diagram showing the configuration appearance of the inspection unit shown in FIG. FIG. 4 is a perspective view showing how a recording medium passes through an image reading area of an inspection unit; FIG. 4 is a diagram showing how a recording medium passes through an image reading area of an inspection unit and an image is read; Diagram showing the position of interference fringes generated when scanning glossy paper A diagram showing the elastic body mounted on the lifting part and the state where the elastic body has a convex shape. FIG. 12 is a diagram showing a state in which reading is performed using the elastic body shown in FIG. 12; FIG. 12 is a diagram showing the correlation between the pressure inside and outside the reading area and the compression amount of the elastic body when reading is performed using the elastic body shown in FIG. Diagram showing Example 2 Diagram showing Example 3 Diagram showing Example 4 Diagram showing Example 5

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. In addition, the following embodiments do not limit the invention according to the scope of claims. Although multiple features are described in the embodiments, not all of these multiple features are essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant description is omitted.

<Description of terms>
In this specification, "recording" (sometimes referred to as "printing") means not only the formation of significant information such as characters and graphics, but also meaninglessness. Furthermore, regardless of whether or not it is actualized so that humans can perceive it visually, it also represents the case of forming an image, design, pattern, etc. on a recording medium or processing the medium.

The term "recording medium" refers not only to paper used in general recording devices, but also to a wide range of materials that can accept ink, such as cloth, plastic film, metal plate, glass, ceramics, wood, and leather. shall be

Furthermore, "ink" (sometimes referred to as "liquid") should be interpreted broadly in the same way as the definition of "print" above. Therefore, by being applied on a recording medium, it can be used for forming an image, design, pattern, etc., processing the recording medium, or treating ink (for example, solidifying or insolubilizing the coloring agent in the ink applied to the recording medium). shall represent a liquid that can be Ink components are not particularly limited, but in this embodiment, it is assumed that a water-based pigment ink containing pigments, water, and a resin is used.

Furthermore, unless otherwise specified, the term "recording element" is used to collectively refer to an ejection port, a liquid path communicating therewith, and an element that generates energy used for ejecting ink.

Furthermore, unless otherwise specified, the term "nozzle" is used to collectively refer to an ejection port, a liquid path communicating therewith, and an element that generates energy used for ejecting ink.
An element substrate (head substrate) for a print head used below does not simply refer to a substrate made of a silicon semiconductor, but refers to a structure provided with elements, wiring, and the like.

Furthermore, the term "on the substrate" indicates not only the top of the element substrate, but also the surface of the element substrate and the inside of the element substrate near the surface. In addition, the term "built-in" as used in the present invention does not mean simply arranging each separate element on the surface of the substrate as a separate element, but rather the term "built-in" means that each element is manufactured as a semiconductor circuit. Integrally formed and manufactured on an element plate by a process or the like.

<Recording system>
FIG. 1 is a front view schematically showing a recording system 1 according to one embodiment of the invention. The recording system 1 is a sheet-fed inkjet printer that transfers an ink image onto a recording medium P via a transfer body 2 to manufacture a recorded matter P′. The recording system 1 includes a recording device 1A and a conveying device 1B. In this embodiment, the X direction, Y direction, and Z direction indicate the width direction (full length direction), depth direction, and height direction of the recording system 1, respectively. The recording medium P is conveyed in the X direction.

<Recording device>
The recording apparatus 1A includes a recording unit 3, a transfer unit 4 and peripheral units 5A-5D, and a supply unit 6. FIG.

<Recording unit>
The recording unit 3 includes multiple recording heads 30 and a carriage 31 . Please refer to FIGS. FIG. 2 is a perspective view of the recording unit 3. FIG. The recording head 30 ejects liquid ink onto the transfer body (intermediate transfer body) 2 to form an ink image of a recording image on the transfer body 2 .

In the case of this embodiment, each recording head 30 is a full-line head extending in the Y direction, and nozzles are arranged in a range covering the width of the image recording area of the maximum size recording medium that can be used. there is The recording head 30 has an ink discharge surface with nozzles on its lower surface, and the ink discharge surface faces the surface of the transfer body 2 with a minute gap (for example, several millimeters) therebetween. In the case of this embodiment, the transfer body 2 is configured to cyclically move on a circular orbit, so the plurality of recording heads 30 are arranged radially.

Each nozzle is provided with an ejection element. The ejecting element is, for example, an element that generates pressure in a nozzle to eject ink in the nozzle, and a known inkjet head technology for an inkjet printer can be applied. Examples of the ejection element include an element that ejects ink by causing film boiling in ink by an electrothermal transducer to form air bubbles, an element that ejects ink by an electromechanical transducer (piezo element), and an element that uses static electricity. Elements for ejecting ink and the like are included. From the viewpoint of high-speed and high-density recording, an ejection element using an electrothermal transducer can be used.

In this embodiment, nine recording heads 30 are provided. Each recording head 30 ejects different types of ink. Different types of inks are, for example, inks with different coloring materials, such as yellow ink, magenta ink, cyan ink, and black ink. One recording head 30 ejects one type of ink, but one recording head 30 may be configured to eject a plurality of types of ink. When a plurality of recording heads 30 are provided in this manner, some of them may eject ink containing no coloring material (for example, clear ink).

A carriage 31 supports a plurality of printheads 30 . Each recording head 30 is fixed to a carriage 31 at the end on the side of the ink ejection surface. As a result, the gap between the ink ejection surface and the surface of the transfer body 2 can be maintained more precisely. The carriage 31 is configured to be displaceable while mounting the recording head 30 under the guidance of the guide member RL. In the case of this embodiment, the guide members RL are rail members extending in the Y direction, and are provided as a pair in the X direction, spaced apart from each other. A slide portion 32 is provided on each side portion of the carriage 31 in the X direction. The slide portion 32 engages with the guide member RL and slides along the guide member RL in the Y direction.

FIG. 3 shows an example of displacement of the recording unit 3, and is a diagram schematically showing the right side of the recording system 1. As shown in FIG. A recovery unit 12 is provided at the rear of the recording system 1 . The recovery unit 12 has a mechanism for recovering the ejection performance of the recording head 30 . Examples of such a mechanism include a cap mechanism that caps the ink ejection surface of the recording head 30, a wiper mechanism that wipes the ink ejection surface, and a suction mechanism that sucks the ink in the recording head 30 from the ink ejection surface with a negative pressure. be able to.

The guide member RL extends from the side of the transfer member 2 to the recovery unit 12 . The recording unit 3 is guided by a guide member RL and can be displaced between an ejection position POS1 indicated by a solid line and a recovery position POS3 indicated by a broken line. is moved by

The ejection position POS<b>1 is the position where the recording unit 3 ejects ink onto the transfer body 2 , and the position where the ink ejection surface of the recording head 30 faces the surface of the transfer body 2 . The recovery position POS3 is a position retreated from the ejection position POS1, and is a position where the recording unit 3 is positioned above the recovery unit 12. FIG. The recovery unit 12 can perform recovery processing for the printhead 30 when the recording unit 3 is positioned at the recovery position POS3. In this embodiment, the recovery process can be executed even while the recording unit 3 is moving before reaching the recovery position POS3. A preliminary recovery position POS2 is located between the ejection position POS1 and the recovery position POS3, and the recovery unit 12 performs a preliminary recovery for the print head 30 at the preliminary recovery position POS2 while the print head 30 is moving from the ejection position POS1 to the recovery position POS3. Recovery processing can be performed.

<Transfer unit>
The transfer unit 4 will be described with reference to FIG. The transfer unit 4 includes a transfer cylinder 41 and an impression cylinder 42 . These cylinders are rotating bodies that rotate around a rotation axis in the Y direction, and have cylindrical outer peripheral surfaces. In FIG. 1, the arrows shown in the figures of the transfer cylinder 41 and the impression cylinder 42 indicate their rotational directions, the transfer cylinder 41 rotating clockwise and the impression cylinder 42 rotating counterclockwise.

The transfer cylinder 41 is a support that supports the transfer body 2 on its outer peripheral surface. The transfer body 2 is provided on the outer peripheral surface of the transfer cylinder 41 continuously or intermittently in the circumferential direction. When provided continuously, the transfer member 2 is formed in an endless strip. When provided intermittently, the transfer body 2 is formed in a band-like shape with ends divided into a plurality of segments, and each segment can be arranged in an arc shape on the outer peripheral surface of the transfer cylinder 41 at equal pitches.

The rotation of the transfer cylinder 41 causes the transfer body 2 to cyclically move on a circular orbit. Depending on the rotational phase of the transfer cylinder 41, the position of the transfer body 2 can be distinguished into a pre-ejection processing region R1, an ejection region R2, post-ejection processing regions R3 and R4, a transfer region R5, and a post-transfer processing region R6. The transfer member 2 cyclically passes through these regions.

The pre-ejection treatment area R1 is an area in which pretreatment is performed on the transfer body 2 before ink is ejected by the recording unit 3, and is an area in which the peripheral unit 5A performs processing. In the case of this embodiment, a reaction liquid is applied. The ejection area R2 is a formation area where the recording unit 3 ejects ink onto the transfer body 2 to form an ink image. The post-ejection processing regions R3 and R4 are processing regions in which the ink image is processed after the ink is ejected, the post-ejection processing region R3 is a region in which processing is performed by the peripheral unit 5B, and the post-ejection processing region R4 is the peripheral unit 5C. This is the area where the processing by is performed. A transfer area R5 is an area where the ink image on the transfer body 2 is transferred to the recording medium P by the transfer unit 4. FIG. The post-transfer processing area R6 is an area where post-processing is performed on the transfer body 2 after transfer, and is an area where processing is performed by the peripheral unit 5D.

In the case of this embodiment, the ejection region R2 is a region having a certain section. The other regions R1, R3 to R6 are narrower than the ejection region R2. In the case of the present embodiment, the pre-ejection treatment region R1 is approximately at the 10 o'clock position, the ejection region R2 is approximately in the range from 11 o'clock to 1 o'clock, and the post-ejection processing region R3 is approximately at the dial of a clock. This is the 2 o'clock position, and the post-ejection treatment region R4 is approximately at the 4 o'clock position. The transfer region R5 is approximately at the 6 o'clock position, and the post-transfer processing region R6 is approximately at the 8 o'clock position.

The transfer member 2 may be composed of a single layer, or may be a laminate of multiple layers. When composed of multiple layers, it may include, for example, three layers of a surface layer, an elastic layer, and a compression layer. The surface layer is the outermost layer having an imaging surface on which an ink image is formed. By providing the compression layer, the compression layer absorbs deformation and disperses local pressure fluctuations, so that transferability can be maintained even during high-speed recording. The elastic layer is the layer between the surface layer and the compression layer.

Various materials such as resins and ceramics can be appropriately used as the material of the surface layer, and materials having a high compressive elastic modulus can be used in terms of durability and the like. Specific examples include acrylic resins, acrylic silicone resins, fluorine-containing resins, condensates obtained by condensing hydrolyzable organosilicon compounds, and the like. The surface layer may be subjected to a surface treatment in order to improve the wettability of the reaction liquid, the transferability of the image, and the like. Examples of surface treatment include flame treatment, corona treatment, plasma treatment, polishing treatment, roughening treatment, active energy ray irradiation treatment, ozone treatment, surfactant treatment, and silane coupling treatment. A plurality of these may be combined. Also, the surface layer can be provided with an arbitrary surface shape.

Examples of materials for the compression layer include acrylonitrile-butadiene rubber, acrylic rubber, chloroprene rubber, urethane rubber, silicone rubber, and the like. When molding such a rubber material, a predetermined amount of a vulcanizing agent, a vulcanization accelerator, etc. are blended, and a foaming agent, hollow fine particles, or a filler such as salt is blended as necessary to form a porous rubber material. may be As a result, the bubble portion is compressed with a change in volume in response to various pressure fluctuations, so deformation in directions other than the direction of compression is small, and more stable transferability and durability can be obtained. As porous rubber materials, there are continuous pore structures in which each pore is continuous with each other, and independent pore structures in which each pore is independent. You may

Various materials such as resins and ceramics can be appropriately used as the member of the elastic layer. Various elastomer materials and rubber materials can be used in terms of processability and the like. Specific examples include fluorosilicone rubber, phenylsilicone rubber, fluororubber, chloroprene rubber, urethane rubber, and nitrile rubber. Also included are ethylene propylene rubber, natural rubber, styrene rubber, isoprene rubber, butadiene rubber, ethylene/propylene/butadiene copolymer, nitrile butadiene rubber and the like. In particular, silicone rubber, fluorosilicone rubber, and phenylsilicone rubber are advantageous in terms of dimensional stability and durability because of their low compression set. In addition, the change in elastic modulus due to temperature is small, which is advantageous in terms of transferability.

Various adhesives and double-sided tapes can be used between the surface layer and the elastic layer and between the elastic layer and the compression layer to fix them. In addition, the transfer body 2 may include a reinforcing layer having a high compression elastic modulus in order to suppress lateral stretching when mounted on the transfer cylinder 41 and to maintain stiffness. Moreover, it is good also considering a woven fabric as a reinforcement layer. The transfer body 2 can be produced by arbitrarily combining each layer made of the above materials.

The impression cylinder 42 is pressed against the transfer body 2 at its outer peripheral surface. At least one grip mechanism for holding the leading edge of the recording medium P is provided on the outer peripheral surface of the impression cylinder 42 . A plurality of gripping mechanisms may be provided spaced apart in the circumferential direction of the impression cylinder 42 . The ink image on the transfer body 2 is transferred when the recording medium P passes through the nip portion between the impression cylinder 42 and the transfer body 2 while being conveyed in close contact with the outer peripheral surface of the impression cylinder 42 .

A drive source such as a motor for driving the transfer cylinder 41 and the impression cylinder 42 is common to them, and the driving force can be distributed by a transmission mechanism such as a gear mechanism.

<Peripheral unit>
The peripheral units 5A-5D are arranged around the transfer cylinder 41. As shown in FIG. In this embodiment, the peripheral units 5A to 5D are, in order, an application unit, an absorption unit, a heating unit, and a cleaning unit.

The application unit 5A is a mechanism that applies a reaction liquid onto the transfer body 2 before the recording unit 3 ejects ink. The reaction liquid is a liquid containing a component that increases the viscosity of the ink. Here, increasing the viscosity of the ink means that the coloring materials, resins, etc. that make up the ink chemically react or physically adsorb when they come into contact with the components that increase the viscosity of the ink. An increase in ink viscosity is observed. This increase in the viscosity of the ink is not only when the viscosity of the ink as a whole increases, but also when the viscosity increases locally due to the aggregation of some of the components that make up the ink, such as colorants and resins. is also included.

The component that increases the viscosity of the ink is not particularly limited, and may be a metal ion, a polymer flocculant, or the like. However, a substance that causes a change in the pH of the ink and agglomerates the coloring material in the ink can be used. can be used. Examples of the mechanism for applying the reaction liquid include a roller, a recording head, a die coating device (die coater), and a blade coating device (blade coater). If the reaction liquid is applied to the transfer body 2 before the ink is ejected onto the transfer body 2, the ink that reaches the transfer body 2 can be immediately fixed. As a result, bleeding in which adjacent inks are mixed can be suppressed.
The absorption unit 5B is a mechanism for absorbing liquid components from the ink image on the transfer body 2 before transfer. By reducing the liquid component of the ink image, bleeding of the image recorded on the recording medium P can be suppressed. If the reduction of the liquid component is explained from a different point of view, it can be expressed as concentrating the ink forming the ink image on the transfer body 2 . Concentrating the ink means that the liquid component contained in the ink is reduced, thereby increasing the content ratio of the solid content such as the coloring material and resin contained in the ink to the liquid component.

Absorption unit 5B includes, for example, a liquid absorption member that contacts the ink image to reduce the amount of the liquid component of the ink image. The liquid absorbing member may be formed on the outer peripheral surface of the roller, or the liquid absorbing member may be formed in the form of an endless sheet and run cyclically. From the viewpoint of protecting the ink image, the moving speed of the liquid absorbing member may be the same as the peripheral speed of the transfer member 2 so that the liquid absorbing member is moved in synchronization with the transfer member 2 .

The liquid absorbing member may include a porous body that contacts the ink image. The pore diameter of the porous body on the surface that contacts the ink image may be 10 μm or less in order to suppress adhesion of ink solids to the liquid absorbing member. Here, the pore diameter means the average diameter, and can be measured by known means such as mercury porosimetry, nitrogen adsorption, SEM image observation, and the like. The liquid component is not particularly limited as long as it does not have a fixed shape, is fluid, and has a substantially constant volume. Examples of liquid components include water, organic solvents, and the like contained in ink and reaction liquids.

The heating unit 5C is a mechanism for heating the ink image on the transfer body 2 before transfer. By heating the ink image, the resin in the ink image is melted and the transferability to the recording medium P is improved. The heating temperature can be the minimum film-forming temperature (MFT) of the resin or higher. MFT can be measured by a generally known method, such as JIS K 6828-2:2003 or ISO2115:1996-compliant equipment. From the viewpoint of transferability and image fastness, the heating may be at a temperature higher than that of the MFT by 10° C. or more, and furthermore, at a temperature higher than that of the MFT by 20° C. or more. The heating unit 5C can use a known heating device such as various lamps such as infrared rays, a hot air fan, and the like. An infrared heater can be used in terms of heating efficiency.

The cleaning unit 5D is a mechanism for cleaning the transfer body 2 after transfer. The cleaning unit 5D removes ink remaining on the transfer body 2, dust on the transfer body 2, and the like. For the cleaning unit 5D, for example, a method of contacting the transfer body 2 with a porous member, a method of rubbing the surface of the transfer body 2 with a brush, a method of scraping the surface of the transfer body 2 with a blade, or the like can be appropriately used. can be done. Also, the cleaning member used for cleaning may have a known shape such as a roller shape or a web shape.

As described above, in this embodiment, the applying unit 5A, the absorbing unit 5B, the heating unit 5C, and the cleaning unit 5D are provided as peripheral units. , a cooling unit may be added. In this embodiment, the temperature of the transfer body 2 may rise due to the heat of the heating unit 5C. After the ink is ejected onto the transfer body 2 by the recording unit 3, if the ink image exceeds the boiling point of water, which is the main solvent of the ink, the ability of the absorption unit 5B to absorb the liquid component may deteriorate. By cooling the transfer body 2 so that the ejected ink is maintained below the boiling point of water, it is possible to maintain the ability to absorb liquid components.

The cooling unit may be a blowing mechanism that blows air to the transfer body 2 or a mechanism that brings a member (for example, a roller) into contact with the transfer body 2 and cools the member by air cooling or water cooling. Alternatively, it may be a mechanism for cooling the cleaning member of the cleaning unit 5D. The cooling timing may be a period after transfer and before application of the reaction liquid.

<Supply unit>
The supply unit 6 is a mechanism that supplies ink to each recording head 30 of the recording unit 3 . The supply unit 6 may be provided on the rear side of the recording system 1 . The supply unit 6 includes a storage section TK that stores ink for each type of ink. The storage section TK may be composed of a main tank and a sub-tank. Each reservoir TK and each recording head 30 communicate with each other through a channel 6a, and ink is supplied to the recording head 30 from the reservoir TK. The channel 6a may be a channel for circulating ink between the reservoir TK and the recording head 30, and the supply unit 6 may include a pump or the like for circulating ink. A degassing mechanism for degassing air bubbles in the ink may be provided in the middle of the flow path 6a or in the reservoir TK. A valve for adjusting the liquid pressure of the ink and the atmospheric pressure may be provided in the middle of the flow path 6a or in the reservoir TK. The height of the reservoir TK and the recording head 30 in the Z direction may be designed such that the ink surface in the reservoir TK is lower than the ink ejection surface of the recording head 30 .

<Conveyor>
The conveying device 1B is a device that feeds the recording medium P to the transfer unit 4 and discharges from the transfer unit 4 the recording material P' onto which the ink image has been transferred. The transport device 1B includes a feed unit 7, a plurality of transport cylinders 8, 8a, two sprockets 8b, a chain 8c and a recovery unit 8d. In FIG. 1, the arrows on the inside of the figure of each component of the transport device 1B indicate the rotation direction of the component, and the arrows on the outside indicate the transport path of the recording medium P or the printed matter P'. The recording medium P is conveyed from the feeding unit 7 to the transfer unit 4, and the recorded matter P' is conveyed from the transfer unit 4 to the collection unit 8d. The side of the feeding unit 7 may be referred to as the upstream side in the transport direction, and the side of the collecting unit 8d may be referred to as the downstream side.

The feeding unit 7 includes a stacking section on which a plurality of recording media P are stacked, and also includes a feeding mechanism that feeds the recording media P one by one from the stacking section to the most upstream conveying cylinder 8 . Each transport cylinder 8, 8a is a rotating body that rotates around a rotation axis in the Y direction, and has a cylindrical outer peripheral surface. At least one gripping mechanism for holding the leading edge of the recording medium P (or the recorded matter P') is provided on the outer peripheral surface of each transport cylinder 8, 8a. Each gripping mechanism controls its gripping operation and release operation so that the recording medium P is transferred between adjacent transport cylinders.

The two transport cylinders 8a are transport cylinders for reversing the recording medium P. As shown in FIG. In the case of double-sided recording on the recording medium P, after transfer to the surface, the recording medium P is passed from the impression cylinder 42 to the transport cylinder 8a adjacent to the downstream side without being passed to the transport cylinder 8. FIG. The recording medium P is turned upside down via the two conveying cylinders 8a and transferred to the impression cylinder 42 again via the conveying cylinder 8 on the upstream side of the impression cylinder 42 . As a result, the back surface of the recording medium P faces the transfer cylinder 41, and the ink image is transferred to the back surface.

Chain 8c is wound between two sprockets 8b. One of the two sprockets 8b is a driving sprocket and the other is a driven sprocket. The rotation of the drive sprocket causes the chain 8c to circulate. The chain 8c is provided with a plurality of gripping mechanisms spaced apart in its longitudinal direction. The gripping mechanism grips the edge of the printed matter P'. The recorded material P′ is transferred from the conveying cylinder 8 located at the downstream end to the gripping mechanism of the chain 8c, and the recorded material P′ gripped by the gripping mechanism is transported to the collection unit 8d by the traveling of the chain 8c, and the gripping is released. be. As a result, the recorded matter P' is loaded in the collection unit 8d.

<Post-processing unit>
Post-processing units 10A and 10B are provided in the transport device 1B. The post-processing units 10A and 10B are arranged downstream of the transfer unit 4 and are mechanisms for performing post-processing on the printed material P'. The post-processing unit 10A performs processing on the front side of the recorded matter P', and the post-processing unit 10B performs processing on the back side of the recorded matter P'. As the content of the processing, for example, the image recording surface of the recorded matter P' may be coated for the purpose of protecting the image, glossing the image, or the like. Examples of coating include application of liquid, welding of sheets, lamination, and the like.

<Inspection unit>
The transport device 1B is provided with inspection units 9A and 9B. The inspection units 9A and 9B are arranged downstream of the transfer unit 4, and are mechanisms for inspecting the printed material P'.

In the case of this embodiment, the inspection unit 9A is a photographing device for photographing an image recorded on the recorded matter P', and includes, for example, an imaging device such as a CCD sensor or a CMOS sensor. The inspection unit 9A captures recorded images during the continuous recording operation. Based on the image photographed by the inspection unit 9A, it is possible to check the time-dependent change of the color tone of the recorded image and determine whether the image data or the recorded data can be corrected. In the case of this embodiment, the inspection unit 9A has an imaging range set on the outer peripheral surface of the impression cylinder 42, and is arranged so as to be able to partially photograph a recorded image immediately after transfer. All recorded images may be inspected by the inspection unit 9A, or may be inspected every predetermined number.

In the case of this embodiment, the inspection unit 9B is also a photographing device for photographing an image recorded on the recorded matter P', and includes, for example, an imaging device such as a CCD sensor or a CMOS sensor. The inspection unit 9B takes a recorded image in the test recording operation. The inspection unit 9B captures the entire recorded image, and based on the image captured by the inspection unit 9B, can perform basic settings for various corrections related to the recorded data. In the case of this embodiment, it is arranged at a position for photographing the printed material P' conveyed by the chain 8c. When the inspection unit 9B captures a recorded image, the running of the chain 8c is temporarily stopped, that is, the transport of the recorded product P' is stopped, and the entirety is captured. The inspection unit 9B may be a scanner that scans the printed material P'.

<Control unit>
Next, the control unit of the recording system 1 will be explained. 4 and 5 are block diagrams of the control unit 13 of the recording system 1. FIG. The control unit 13 is communicatively connected to a host device (DFE) HC2, and the host device HC2 is communicably connected to the host device HC1.

The host device HC1 may be, for example, a PC (Personal Computer), which is an information processing device, or a server device. Moreover, the communication method between the host device HC1 and the host device HC2 may be wired or wireless, and is not particularly limited.

The host device HC1 generates or stores document data that is the basis of a recorded image. The manuscript data here is generated, for example, in the form of an electronic file such as a document file or an image file. This document data is sent to the host device HC2, and the host device HC2 converts the received document data into a data format that can be used by the control unit 13 (for example, RGB data representing an image in RGB). The converted data is transmitted as image data from the host device HC2 to the control unit 13, and the control unit 13 starts recording operation based on the received image data.

In this embodiment, the control unit 13 is roughly divided into a main controller 13A and an engine controller 13B. Main controller 13A includes processing unit 131 , storage unit 132 , operation unit 133 , image processing unit 134 , communication I/F (interface) 135 , buffer 136 and communication I/F 137 .

The processing unit 131 is a processor such as a CPU, executes programs stored in the storage unit 132, and controls the entire main controller 13A. The storage unit 132 is a storage device such as a RAM, a ROM, a hard disk, or an SSD, stores programs executed by the CPU 131 and data, and provides the CPU 131 with a work area. In addition to the storage unit 132, an external storage unit may be further provided. The operation unit 133 is, for example, an input device such as a touch panel, keyboard, or mouse, and receives user instructions. The operation unit 133 may have, for example, a configuration in which an input unit and a display unit are integrated. Note that user operations are not limited to inputs via the operation unit 133, and may be configured to receive instructions from the host device HC1 or the host device HC2, for example.

The image processor 134 is, for example, an electronic circuit having an image processor. The buffer 136 is, for example, RAM, hard disk or SSD. A communication I/F 135 communicates with the host device HC2, and a communication I/F 137 communicates with the engine controller 13B. Broken arrows in FIG. 4 illustrate the flow of image data processing. Image data received from the host device HC2 via the communication IF 135 is accumulated in the buffer 136. FIG. The image processing unit 134 reads the image data from the buffer 136 , performs predetermined image processing on the read image data, and stores the processed image data in the buffer 136 again. The image data after image processing stored in the buffer 136 is transmitted from the communication I/F 137 to the engine controller 13B as print data used by the print engine.

As shown in FIG. 5, the engine controller 13B includes control units 14 and 15A to 15E, acquires detection results of the sensor group and the actuator group 16 provided in the recording system 1, and performs drive control. Each of these control units includes a processor such as a CPU, storage devices such as RAM and ROM, and interfaces with external devices. Note that the division of the control units is an example, and a part of the control may be executed by a plurality of subdivided control units. It may be configured to be performed by one control unit.

The engine control unit 14 controls the entire engine controller 13B. The recording control unit 15A converts the recording data received from the main controller 13A into a data format suitable for driving the recording head 30, such as raster data. The recording control section 15</b>A controls ejection of each recording head 30 .

The transfer control section 15B controls the application unit 5A, the absorption unit 5B, the heating unit 5C, and the cleaning unit 5D.

The reliability control section 15C controls the supply unit 6, the recovery unit 12, and the drive mechanism that moves the recording unit 3 between the ejection position POS1 and the recovery position POS3.

The transport control section 15D controls the driving of the transfer unit 4 and the transport device 1B. The inspection control section 15E controls the inspection unit 9B and the inspection unit 9A.
Among the sensor group and the actuator group 16, the sensor group includes a sensor for detecting the position and speed of the movable portion, a sensor for detecting temperature, an imaging device, and the like. The actuator group includes motors, electromagnetic solenoids, electromagnetic valves, and the like.

<Operation example>
FIG. 6 is a diagram schematically showing an example of the recording operation. The following steps are cyclically performed while the transfer cylinder 41 and the impression cylinder 42 are rotated. As shown in state ST1, first, the reaction liquid L is applied onto the transfer member 2 from the application unit 5A. The portion of the transfer body 2 to which the reaction liquid L is applied moves as the transfer cylinder 41 rotates. When the portion to which the reaction liquid L is applied reaches below the recording head 30, ink is ejected from the recording head 30 onto the transfer body 2 as shown in state ST2. An ink image IM is thus formed. At this time, the ejected ink mixes with the reaction liquid L on the transfer body 2, thereby promoting aggregation of the coloring material. The ejected ink is supplied to the recording head 30 from the reservoir TK of the supply unit 6 .

The ink image IM on the transfer body 2 moves as the transfer body 2 rotates. When the ink image IM reaches the absorbing unit 5B, the liquid component is absorbed from the ink image IM by the absorbing unit 5B as shown in state ST3. When the ink image IM reaches the heating unit 5C, the ink image IM is heated by the heating unit 5C as shown in state ST4, the resin in the ink image IM is melted, and the ink image IM is formed. In synchronism with the formation of the ink image IM, the recording medium P is transported by the transport device 1B.

As shown in state ST5, the ink image IM and the recording medium P reach the nip portion between the transfer body 2 and the impression cylinder 42, the ink image IM is transferred to the recording medium P, and the recorded matter P' is manufactured. . After passing through the nip portion, the image recorded on the recorded product P' is photographed by the inspection unit 9A, and the recorded image is inspected. The recorded matter P' is conveyed to the collecting unit 8d by the conveying device 1B.

The portion of the transfer member 2 on which the ink image IM was formed is cleaned by the cleaning unit 5D when it reaches the cleaning unit 5D as shown in state ST6. After the cleaning, the transfer body 2 rotates once, and the transfer of the ink image to the recording medium P is repeated in the same procedure. In the above description, for ease of understanding, one rotation of the transfer body 2 is used to transfer the ink image IM onto one recording medium P once. Transfer of the ink image IM onto a plurality of recording media P can be performed continuously.

Continuing such a recording operation requires maintenance of each recording head 30 .

FIG. 7 shows an operation example during maintenance of each recording head 30 . A state ST11 indicates a state in which the recording unit 3 is positioned at the ejection position POS1. State ST12 indicates a state in which the recording unit 3 is passing through the preliminary recovery position POS2, and the recovery unit 12 executes the process of recovering the ejection performance of each recording head 30 of the recording unit 3 during passage. Thereafter, as shown in state ST13, the recovery unit 12 performs a process of recovering the ejection performance of each print head 30 while the print unit 3 is positioned at the recovery position POS3.

Next, a method for inspecting the quality of an image formed on a recording medium in the recording system configured as described above will be described. This inspection is performed when the recording head is replaced, when the recording system is periodically inspected, or when the user arbitrarily selects it.

<Detailed Description of Inspection Unit 9B>
FIG. 8 is a diagram showing the appearance of the configuration of the inspection unit 9B shown in FIG. 8(B) is a perspective view of a portion provided with the inspection unit 9B shown in FIG. 1, and FIG. 8(A) shows the configuration of the area surrounded by an ellipse in FIG. 8(B). An enlarged perspective view is shown.

The inspection unit 9B in this embodiment is a scanner that optically reads an image, and a lift-up unit 9C is provided facing the scanner across the transport path of the recording medium P. FIG. In this embodiment, the scanner has a reading width of 850 mm so that it can read an A0 size recording medium in the longitudinal direction. Further, if the recording medium is in a stationary state, it has a reading area in which an image of A4 width (210 mm) can be read at once in the conveying direction of the recording medium. Therefore, this scanner has a reading area capable of reading an image of width 850 mm×length 210 mm at one time. An elevating unit 9D located above the lift-up unit 9C can move in the direction of arrow A, which is the direction perpendicular to the conveying direction of the recording medium P, and press the recording medium P against the scanner. The white plate provided on the upper surface of the lifting section 9D has a width of 850 mm and a length of 210 mm corresponding to the size of the reading area of the scanner, and can press the recording medium P over the entire reading area of the scanner.

FIG. 9 is a perspective view showing how the recording medium passes through the reading area of the inspection unit.

In the example shown in FIG. 9, a plurality of recording media P having images transferred thereon and gripped by the gripping mechanism 8e are continuously conveyed from right to left as indicated by an arrow A. there is In this example, the preceding recording medium P reaches between the detection surface 9F of the inspection unit 9B and the lifting section 9D of the lift-up unit 9C, and the succeeding recording medium P reaches the transport guide 9E on the right side. Each of these gripping mechanisms 8e is fixed to a chain clipper 8f, and the chain clipper 8f meshes with the chain 8c. In this manner, the recording medium P is transported in the direction of the arrow A as the chain 8c circulates.

Now, the lifting section 9D can move in the direction of the arrow B perpendicular to the arrow A, thereby pressing the recording medium P reaching between the detection surface 9F and the lifting section 9D against the detection surface 9F. can do.

The image recorded by the recording system is processed by stopping the conveyance of the recording medium P, further pressing the recording medium P to fix it, and reading the image at regular intervals in the conveyance direction of the recording medium with a scanner. The quality of the image is checked. In this way, the printed matter recorded on the recording medium is inspected.

FIG. 10 is a diagram showing how the recording medium passes through the reading area of the inspection unit and the image is read.

10 is a view of the inspection unit 9B and the lift-up unit 9C from a direction (perpendicular to the paper surface) orthogonal to the arrow A that is the conveying direction of the recording medium and the arrow B that is the moving direction of the lifting section 9D in FIG. It is a diagram.

As shown in FIG. 10A, in step S110, the recording medium P gripped by the gripping mechanism 8e is conveyed to directly below the scanner 9B by rotating the chain 8c engaged with the chain clipper 8f. At this time, the lifting section 9D of the lift-up unit 9C is at a position (first position) retracted from the transport path of the recording medium so as not to interfere with the transport of the recording medium.

Next, as shown in FIG. 10B, in step S120, when the image (1) recorded on the recording medium P shown on the right side reaches the reading area of the scanner 9B, the conveyance of the recording medium P is stopped. do. Then, the elevating unit 9D of the lift-up unit 9C is moved upward (second position) to press and fix the recording medium P against the detection surface 9F of the scanner 9B, and the image (1) area is scanned by the scanner. Read by 9B. In this reading, an image of width 850 mm×length 210 mm corresponding to strip-shaped image (1) is read at once.

When the reading is finished, as shown in FIG. 10C, in step S130, the lifting section 9D of the lift-up unit 9C is again moved downward (to the first position). Then, the chain 8c engaged with the chain clipper 8f is rotated to rotate the recording medium P gripped by the grip mechanism 8e until the image (2) recorded on the recording medium P reaches the reading area of the scanner 9B. resume transport of

Thereafter, as shown in FIG. 10(d), in step S140, the elevating section 9D of the lift-up unit 9C is again moved upward (second position) to move the recording medium P against the detection surface 9F of the scanner 9B. Then, the image (2) area is read by the scanner 9B. In this reading, an image of width 850 mm×length 210 mm corresponding to the belt-shaped image (2) is read at once.

Thereafter, the elevating section 9D of the lift-up unit 9C is moved downward (first position) to eject the recording medium P from the inspection unit 9B.

11A and 11B are enlarged views of the state before and after reading the recording medium. FIG. 11A shows the state before reading, and FIG. 11B shows the state during reading. The reading section 9B reads the reading area 9G of the recording medium P. FIG. When the recording medium P is glossy paper, when the recording medium is pressed against the detection surface of the glass (transmissive member) by the pressing portion, the glossy paper comes into close contact with the glass as shown in FIG. As a result of the high pressure applied to , interference fringes 9? are produced. The reading section 9B is affected by the interference fringes 9L and cannot read the image accurately. The generation of interference fringes correlates with the contact pressure between the glass and the paper, and has the characteristic of being generated when a pressure exceeding approximately 5 [gf/cm ² ] (gram force per square centimeter) is applied.

<Example 1>
In order to cope with the characteristics of glossy paper described above, it is preferable to press with a pressure less than 5 [gf/cm ² ]. However, when the size of the recording medium is large or when the recording medium is curled, in order to prevent the deterioration of the reading accuracy due to the influence of the paper floating in the reading area, the pressure is sufficient to cancel the paper floating. It is necessary to press and hold the recording medium uniformly on the reading area of the reading section 9B. In this case, the recording medium is strongly pressed with a pressing force of 5 [gf/cm ² ] or more outside the reading area so as to follow the reading area, and a pressure of, for example, 2 [gf/cm ² ] or less within the reading area. By lightly pressing with , it is possible to read glossy paper with high accuracy.

FIG. 12 shows the configuration of the elastic body 9H in this embodiment. In contrast to the conventional plate-like elastic body 9H shown in FIG. 12(A), in the present embodiment, as shown in FIG. A convex elastic member 9K is arranged. The elastic member 9K is disposed so as to contact the recording medium and bring the recording medium into close contact with the glass when the elevating section 9D is positioned at the second position during image reading. In this embodiment, the elastic member 9K is arranged only in the longitudinal direction of the elastic body, but it may be arranged only in the lateral direction or around the entire circumference. In this embodiment, the size of the recording medium to be read is larger than the interval between the opposing elastic members, but it may be smaller. Also, one elastic member 9K may have an uneven shape so as to contact the recording medium at a plurality of points.

FIGS. 13(A) and 13(B) show the states before and after reading when the present invention is carried out. As shown in FIG. 13B, during reading, the outer region 9M of the recording medium is first pressed against the glass 9J by the elastic member 9K arranged in the outer region 9M outside the reading region, and the elastic member 9K is pressed. The elastic body 9H is deformed by the thickness of . Next, the inside of the reading area is pressed with a light pressure compared to the outer area 9M. As a result, interference fringes 9L are generated in the outer area 9M outside the reading area, but not in the reading area 9K. FIG. 14 shows the correlation between the pressure generated inside and outside the reading area and the amount of deformation of the elastic body generated by this configuration. This correlation varies depending on the spring pressure of the pressing plate, the characteristics of the elastic body, the area and thickness of the elastic member 9K, and the area of the reading area. As shown in FIG. 14, in this embodiment, the portion of the outer region 9M that is in contact with the elastic member 9K is pressed with a pressing force of about 60 [gf/cm ² ] to hold the recording medium while reading. In the area, the pressing force is about 0.9 [gf/cm ² ]. In this case, such a pressure relationship prevents interference fringes from occurring in the reading area. By arranging the elastic member 9K outside the reading area in this manner, the elastic member 9K functions as a pressure adjusting member that makes the pressing force inside the reading area smaller than the pressing force in the outer area.

<Other Examples>
15 (Example 2), FIG. 16 (Example 3), FIG. 17 (Example 4), and FIG. FIG. 15 shows a configuration in which an elastic member 9K that protrudes toward the elevating section is provided outside the reading area of the elastic body 9H. By arranging the elastic member 9K between the elastic body 9H and the lifting table 9D in this manner and providing a space for the elastic body 9H to move toward the lifting section 9D in the reading area, the elastic member 9K is arranged during image reading. The pressing force of the outer area can be higher than the pressing force of the reading area.

FIG. 16 shows a third embodiment in which an elastic member 9K projecting toward the elevation unit 9D is provided on the surface on the elevation unit side outside the reading area of the document glass. As shown in FIG. 16, by arranging the elastic member 9K on the glass side (transmissive member side), it is possible to reduce the pressing force when the recording medium comes into close contact with the glass in the reading area. FIG. 17 shows Example 4 in which elastic members protruding toward the recording medium are provided at a position corresponding to the outer region of the elastic body and at a position corresponding to the outer region on the glass side (transmissive member side). FIG. 4 is a diagram showing; As shown in FIG. 17, in the fourth embodiment, the elastic member on the side of the transmission member and the elastic member on the side of the elevating unit sandwich the recording medium when moving from the second position to the first position during image reading. Abut possible. In FIG. 18, an elastic member is provided between the elastic body 9H and the elevating section 9D outside the reading area of the elastic body, and the surface of the manuscript glass outside the reading area on the elevating section side is projected toward the elevating section side. FIG. 10 is a diagram showing Example 5 in which an elastic member is provided; As shown in FIGS. 15 to 18, in any of the configurations of Embodiments 2 to 5, a force can be applied so that the pressing force in the outer region becomes the pressing force in the reading region. While preventing the occurrence of stripes, the recording medium can be held and read with high accuracy.

In this embodiment, the transparent member is glass in order to hold the recording medium while maintaining the distance between the reading unit 9B and the recording medium. A member may be configured.

The present invention supplies a program that implements one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in the computer of the system or apparatus reads and executes the program. It can also be realized by processing to It can also be implemented by a circuit (for example, ASIC) that implements one or more functions.

The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the claims are appended to make public the scope of the invention.

2 transfer body, 3 recording unit, 4 transfer unit, 5A application unit, 5B absorption unit, 5C heating unit, 5D cleaning unit, 8c chain, 8e grip mechanism, 8f chain clipper, 9B inspection unit (scanner), 9C lift-up unit , 9D lifting section, 9E transport guide, 9F detection surface, 9G reading area, 9H elastic body, 9I glass holding frame, 9J platen glass, 9K elastic member, 9L interference fringes, 30 recording head, P recording medium

Claims (13)

reading means for reading an image formed on a recording medium;
a transmissive member disposed between the recording medium and the reading means;
pressing means that faces the transmission member and presses the recording medium against the transmission member;
a pressure adjusting member disposed in an area outside the reading area of the reading means and overlapping the recording medium, and for applying a higher pressing force by the pressing means to the recording medium in the outer area than in the reading area;
An image reading device comprising: The pressure adjusting member is an elastic member having a shape convex toward the transmissive member and arranged on the pressing means so as to press against the recording medium outside the reading area during image reading. The image reading device according to claim 1. The pressure adjusting member is an elastic member having a shape that protrudes toward the pressing means and is arranged on the side of the transmissive member so as to contact the recording medium outside the reading area during image reading. 3. The image reading device according to claim 1 or 2. The pressure adjusting member is
a first elastic member having a shape protruding toward the transmissive member and arranged on the pressing means so as to press against the recording medium outside the reading area during image reading;
a second elastic member having a shape protruding toward the pressing means, the second elastic member being disposed on the transmissive member so as to contact the recording medium outside the reading area during image reading;
with
2. The image reading apparatus according to claim 1, wherein said first and second elastic members are arranged at positions for sandwiching said recording medium during image reading. 5. The image reading apparatus according to claim 2, wherein a plate-like elastic body is provided between said pressing means and said pressure adjusting member. 5. The image reading apparatus according to claim 2, wherein a plate-like elastic body is provided between said pressure adjusting member and said recording medium. 7. The image reading apparatus according to claim 5, wherein the elastic body presses the reading area and the outer area during image reading. the pressing means includes an elevating means that moves up and down between a first position away from the transmissive member and a second position at which the recording medium is pressed against the transmissive member;
While the pressing means is moved from the first position to the second position by the elevating means, the elastic body contacts the recording medium after the pressure adjusting member contacts the recording medium. 6. The image reading device according to claim 5, characterized by: 8. The recording medium according to any one of claims 1 to 7, wherein a pressure for pressing the recording medium against the transparent member during image reading is 2 [gf/cm ² ] or less in the reading area. The described image reader. 8. The recording medium according to any one of claims 1 to 7, wherein a pressure for pressing the recording medium against the transmissive member during image reading is 5 [gf/ ^cm2 ] or more outside the reading area. The described image reader. 10. The image reading apparatus according to claim 1, wherein said reading means is a scanner that optically reads an image. 11. The image reading apparatus according to claim 1, wherein the transmissive member is glass. 13. The image reading apparatus according to claim 1, further comprising conveying means for conveying the recording medium so as to pass through the reading area.

Images