JP2006334891A - Image recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image recorder which records images without inclinations to a recording material, and moreover improves a recording speed without an image quality of recording images damaged in the image recorder which records the images by using light beams. <P>SOLUTION: The image recorder 1 is equipped with a control part 33 which controls each part. A signal detected by an acceleration sensor 25 is input to the control part 33. It is detected on the basis of the signal whether a head support 18 stops. The control part 33 controls an exposure control circuit 24 to operate an exposure head 13 when the head support 18 stops, and to shed the light beams onto the recording material 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image recording apparatus, and more particularly to an image recording apparatus that records an image by exposing a light beam from an exposure light source onto an exposure surface of a recording material using optical scanning.

  Conventionally, in a printing apparatus or the like, an image recording apparatus that records an image by subjecting a recording material to light exposure is used. An image recording apparatus irradiates light onto a recording material by irradiating a light beam from an exposure light source composed of a light emitter such as an LED or a laser onto an exposure surface of the recording material via an optical system including a lens. An image is recorded on a recording material by forming an image of a beam.

  Such an image recording apparatus includes an outer surface scanning type in which a recording material is wound around the outer peripheral surface of the drum and light is irradiated from the outside of the drum, and an inner peripheral surface of the drum. And an inner surface scanning type in which an exposure head for exposure is provided inside the drum and the recording material is exposed by irradiating light from the inside of the drum.

  By the way, in recent years, it has been desired to increase the recording speed of an image recording apparatus, and the recording speed of an image recording apparatus that records an image by subjecting a recording material to light exposure is the exposure channel of an exposure head that irradiates light. Depends on the number. For this reason, means for increasing the number of exposure channels is taken in order to increase the recording speed. That is, in the case of the outer surface scanning method, for example, a method of increasing the number of exposure channels by guiding light beams from a plurality of light sources by optical fibers and bundling the optical fibers and arranging them in an array (see, for example, Patent Document 1). Or a method of increasing the number of exposure channels by branching the light emitted from the light source into a plurality of light beams and modulating the plurality of light beams individually by a spatial modulation element and forming an image on the surface of the recording material (See, for example, Patent Document 2). Further, in the case of the inner surface scanning method, for example, by providing means for performing main scanning by rotating a light beam with a so-called rotating polygon mirror or the like, multiple beam scanning can be performed even in a limited space inside the drum. A method has been proposed (see, for example, Patent Document 3).

  However, in an image recording apparatus using a light beam, the recording material moving at a constant speed in the main scanning direction is irradiated with the light beam while moving the exposure light source in the sub-scanning direction. It is known that an image inclined with respect to the recording material is recorded without being parallel to the scanning direction of the exposure of the light beam.

  For this reason, a technique for recording an image having no inclination with respect to the recording material by disposing the recording material so that the edge in the main scanning direction of the recording material is parallel to the scanning direction of the light beam exposure is disclosed. (For example, see Patent Document 4).

  Also, a technique for recording an image having no inclination with respect to the recording material by correcting the image data according to the inclination angle of the scanning direction of the light beam with respect to the main scanning direction in which the recording material moves before recording the image. Is disclosed (for example, see Patent Document 5).

Further, the rotating drum with the recording material attached is continuously rotated in the main scanning direction, while the exposure light source is moved intermittently in the sub-scanning direction, and the light beam is transmitted when the movement of the exposure light source is stopped. A technique for recording an image having no inclination with respect to a recording material by irradiating the recording material is disclosed (for example, see Patent Document 6).
JP 2000-141749 A JP-A-8-90831 Japanese Patent Laid-Open No. 5-5846 JP 2004-258205 A Japanese Patent Laid-Open No. 9-23320 JP 2003-341114 A

  However, as disclosed in Patent Document 4, the means for arranging the recording material so that the edge in the main scanning direction of the recording material is parallel to the scanning direction of the light beam exposure inclines the recording material in the rotation direction of the rotary drum. Therefore, there is a problem that the mechanism of the apparatus becomes complicated.

  Further, as in Patent Document 5, the means for recording an image using the corrected image data temporarily stores the acquired image data and corrects the image data in accordance with the inclination of the recording material with respect to the rotating drum. There is a problem that a large-capacity memory and a complicated calculation are required.

  Further, as in Patent Document 6, the means for recording an image when the movement of the exposure light source is stopped moves the exposure light source in the sub-scanning direction every other rotation of the rotary drum, so that time is required for image recording. It has such a problem. Also, the recording head mounted with the exposure light source is moved by the ball screw, but there is a problem that it is difficult to precisely control the stop position of the recording head due to play in the ball screw, and there are multiple exposure light sources. In some cases, since a ball screw corresponding to a recording head on which each exposure light source is mounted is required, there is a problem that the image recording apparatus becomes large.

  The present invention has been made in view of the above points, and provides an image recording apparatus capable of recording an image without an inclination with respect to a recording material and further improving the recording speed without impairing the image quality of the recorded image. It is an object to do.

In order to solve such a problem, the invention described in claim 1
A holding member for holding the recording material;
An exposure head for exposing the recording material by irradiating the recording material with a light beam;
Main scanning means for relatively moving the recording material and the light beam so that the recording material is exposed along the main scanning direction by the light beam;
A moving mechanism for moving the exposure head in a sub-scanning direction orthogonal to the main scanning direction;
The moving mechanism is controlled to move the exposure head when the recording material is not present at the light beam irradiation destination, and the light beam is applied to the recording material when the exposure head is stopped. And a control unit for controlling the exposure head to irradiate.

The invention according to claim 2 is the image recording apparatus according to claim 1,
An acceleration sensor for detecting the acceleration of the exposure head;
The control unit detects whether or not the exposure head is stopped by the acceleration sensor.

The invention according to claim 3 is the image recording apparatus according to claim 1 or 2,
The moving mechanism is a linear motor including a magnet as a stator and an electromagnetic coil as a mover.

  According to the first aspect of the present invention, the exposure head is moved in the sub-scanning direction when the recording material is not present at the irradiation destination of the exposure head, and the recording material is exposed when the exposure head is stopped. Therefore, there is an effect that an image having no inclination can be recorded on the recording material.

  According to the second aspect of the present invention, it is possible to detect whether or not the exposure head is stopped by the acceleration sensor and to record an image when the exposure head is stopped. In this way, the image quality can be prevented from being deteriorated by recording an image while the image is being recorded.

  According to the third aspect of the present invention, since the linear motor is provided and the exposure head is moved by the linear motor, there is an effect that vibration and noise accompanying the movement of the exposure head can be reduced.

  The configuration of the image recording apparatus according to the present invention will be described below with reference to FIGS. However, the scope of the invention is not limited to the illustrated examples.

  FIG. 1 is a top view showing a schematic configuration of an image recording apparatus 1 as an embodiment of the present invention, and FIG. 2 is a side view showing a schematic configuration of the image recording apparatus 1.

  As shown in FIG. 2, the image recording apparatus 1 is provided with a flat plate-like device mount 2 that fixes each member for performing image recording. As shown in FIG. 1, a rotating shaft 3 is provided on the apparatus base 2 so as to extend. The rotating shaft 3 is provided with a cylindrical rotating drum 4 that is a main scanning means and rotates coaxially. The rotating drum 4 holds a recording material 5 for forming an image. The rotating drum 4 is also a holding member for the recording material 5. The direction in which the rotating shaft 3 extends is defined as a sub-scanning direction Y. An end of the rotating shaft 3 is rotatably supported by a support member 6 erected on the apparatus base 2, and the rotating drum 4 rotates with the rotation of the rotating shaft 3. A circumferential direction in which the rotating drum 4 rotates is a main scanning direction X.

  Further, as shown in FIG. 1, a rod-shaped stator 7 and a guide rail 8 are provided on the device base 2 so as to extend in parallel with the direction in which the rotary shaft 3 extends. A direction in which the stator 7 and the guide rail 8 extend is defined as a sub-scanning direction Y.

  As shown in FIG. 3, the stator 7 includes a cylindrical pipe-shaped member 9 and a plurality of columnar magnets 10 housed in the pipe-shaped member 9. In the pipe-shaped member 9, a plurality of columnar magnets 10 are arranged in series so that the same magnetic poles of magnets adjacent to each other face each other.

  The pipe-shaped member 9 is made of a non-magnetic material such as an aluminum alloy, a copper alloy, or non-magnetic stainless steel, and reduces the magnetic field acting on the mover 11 (see FIG. 3) disposed outside the pipe-shaped member 9. It is preferable to form it as thin as possible. As a material for the magnet 10, a rare earth magnet having a high magnetic flux density is used. In particular, it is preferable to use a neodymium-based magnet, for example, a neodymium-iron-boron magnet (Nd-Fe-B magnet), as the rare earth magnet, and higher thrust can be obtained than when other magnets are used. .

  A stator support member 7 that supports the stator 7 is erected on the apparatus base 2 at the end of the stator 7.

  A cylindrical movable element 11 that moves linearly along the outer peripheral surface of the stator 7 is provided on the outer periphery of the stator 7. The mover 11 is provided in correspondence with the number of exposure heads 13 that irradiate the rotating drum 4 with light. In this embodiment, an example in which two movable elements 11 are provided is shown, but the present invention is not limited to this, and a single movable element or more movable elements may be provided. The outer peripheral surface of the stator 7 and the inner peripheral surface of the mover 11 are kept at a very small distance, and the mover 11 may be slid and moved with the stator 7. You may move without doing it. The mover 11 includes an electromagnetic coil 14 composed of a plurality of phases.

  A coil holding member 15 that operates in accordance with the movement of the mover 11 is provided on the outer periphery of the mover 11. Further, a guide member 16 is provided on the outer periphery of the guide rail 8 so as to keep a small distance from the outer peripheral surface of the guide rail 8, and is erected on the apparatus stand 2 at the end of the guide rail 8. It is supported by the rail support member 17. A head support base 18 is installed between the guide member 16 and the coil holding member 15, and the head support base 18 moves along the stator 7 and the guide rail 8 in the sub-scanning direction as the mover 11 moves. Y can be reciprocated freely.

  In the present invention, a linear motor 19 is composed of the stator 7 and the mover 11. The linear motor 19 is a moving mechanism that moves the exposure head 13. In the linear motor 19, when a current flows through the electromagnetic coil 14 of the mover 11, a magnetic field is generated in the electromagnetic coil 14, and repulsive force and attractive force between the magnets are generated between the electromagnetic coil 14 and the magnet 10 of the stator 7. The head support 18 is moved in the sub-scanning direction Y using the repulsive force and the attractive force between the magnets.

  As shown in FIG. 4, a plurality of exposure light sources 20 that irradiate light toward the recording material 5 held on the rotary drum 4 are fixed to the upper surface of the head support base 18. In this embodiment, a semiconductor laser diode is used as the exposure light source 20. The exposure light source 20 is connected to the end portion of the optical fiber 21 corresponding to each exposure light source 20, and the optical beam 21 transmits the light beam L of the exposure light source 20 to the other end.

  The other end of the optical fiber 21 is connected to an optical fiber array 22 constituted by a predetermined arrangement of a plurality of optical fibers 21 so that light beams L from the plurality of optical fibers 21 are emitted. A lens 23 for converging a plurality of light beams L emitted from the optical fiber 21 is provided on the side opposite to the exposure light source 20 of the optical fiber array 22, and the plurality of light beams L are recorded while maintaining the arrangement of the optical fibers 21. It converges on the material 5. Exposure of the light beam L from the exposure head 13 is controlled by an exposure control circuit 24 (see FIG. 6).

  An acceleration sensor 25 for measuring acceleration is provided on the upper surface of the head support base 18. As the acceleration sensor 25, a sensor using a strain gauge, a sensor using a piezoelectric element, or the like can be used.

  A linear encoder 26 for detecting the position of the head support base 18 is installed between the stator support member 7 and the rail support member 17 under the head support base 18. The linear encoder 26 is installed on the back surface of the head support base 18 and the encoder scale 27 extending in parallel with the sub-scanning direction Y on the apparatus base 2. 27 and an optical sensor 28 for detecting the position by receiving the reflected light.

  As shown in FIG. 5, the optical sensor 28 includes a light source 29 that emits a light beam L. A condenser lens 30 is provided between the encoder scale 27 and the light source 29 to focus the light beam L from the light source 29 on the recording material 5 to form an image. A scanning grating 31 in which two phase gratings are alternately inserted is provided between the condenser lens 30 and the encoder scale 27, and the phase of the light from the condenser lens 30 that has passed through the scanning grating 31 is shifted. The light enters the encoder scale 27 as a parallel light beam. Furthermore, a plurality of light receiving elements 32 that receive light reflected by the encoder scale 27 and transmitted through the scanning grating 31 and the condenser lens 30 are provided on the light source 29 side of the condenser lens 30.

  Next, the control configuration of the image recording apparatus 1 will be described with reference to FIG.

  FIG. 6 is a block diagram showing a control configuration of the image recording apparatus 1.

As shown in FIG. 6, the image recording apparatus 1 includes a control unit 33 that controls each unit, and the control unit 33 includes a ROM 34, a RAM 35, a CPU 36, and the like.
The ROM 34 is a read-only memory, and stores various application programs as the image recording apparatus 1 executed by the CPU 36, data used for various operations, and the like.
The RAM 35 is a volatile semiconductor memory, for example, and has a work area for temporarily storing programs, data, and the like being processed by the CPU 36.
The CPU 36 reads various application programs related to various functions of the image recording apparatus 1 stored in the ROM 34, expands them in a work area in the RAM 35, and executes various processes such as an image reading process according to the programs. ing.

The controller 33 controls the rotating drum drive mechanism 37 to rotate the rotating drum 4 in the main scanning direction X.
Further, the control unit 33 detects whether or not the recording material 5 is present at the irradiation destination of the exposure head 13. When the recording material 5 is not present at the irradiation destination of the exposure head 13, the control unit 33 turns the linear motor 19. The head support 18 is moved to the sub-scanning Y by driving control.
As the head support 18 moves, the control unit 33 receives a light reception signal from the optical sensor 28, and can detect the position of the head support 18 in the sub-scanning direction Y based on the light reception signal. It is like that.

  The control unit 33 receives a signal detected by the acceleration sensor 25, and detects whether or not the head support base 18 is stopped based on this signal. The control unit 33 controls the exposure control circuit 24 to operate the exposure head 13 and irradiate the recording material 5 with the light beam L when the head support 18 is stopped.

  Next, the operation in this embodiment will be described.

  When image data is input from the outside, the control unit 33 holds the recording material 5 on the rotating drum 4 and drives and controls the rotating drum driving mechanism 37 to rotate the rotating drum 4 in the main scanning direction X at a constant speed. . At the same time, the control unit 33 drives and controls the exposure control circuit 24 to irradiate the light beams L from the plurality of exposure light sources 20 corresponding to the image data, and the light beams L reach the optical fiber array 22 through the optical fibers 21. The recording material 5 is exposed through the lens 23 while maintaining a predetermined arrangement. As a result, the recording material 5 held on the rotary drum 4 records an image by the exposure head 13 while rotating in the main scanning direction X.

  When the exposure head 13 records a predetermined image along the main scanning direction X of the recording material 5, the control unit 33 drives and controls the linear motor 19, and the recording material 5 is not present at the irradiation destination of the exposure head 13. Then, the head support 18 is moved to a predetermined position where the next image recording is performed in the sub-scanning direction Y. The position of the head support 18 in the sub-scanning direction Y is detected by a light reception signal from the optical sensor 28. When the head support base 18 moves to a predetermined position, the control unit 33 detects the acceleration of the head support base 18 by the acceleration sensor 25 and determines whether or not the head support base 18 is stopped. When it is determined that the head support base 18 is not stopped, the control unit 33 detects the acceleration of the head support base 18 again to determine whether the head support base 18 is stopped. Further, when the control unit 33 determines that the head support 18 is stopped, the control unit 33 starts from the exposure head 13 in response to the recording material 5 reaching the exposure destination from the exposure head 13 by the rotation of the rotary drum 4. The recording material 5 is irradiated with a light beam L. Since the light beam L is irradiated with the exposure head 13 stopped, the light beam L is irradiated in a direction parallel to the main scanning direction X in which the rotating drum rotates. As a result, the recording material 5 is exposed and an image is recorded.

  Thereafter, the image recording apparatus 1 repeats the above operations, whereby an image is recorded on the recording material 5.

  As described above, the image recording apparatus 1 according to the present invention moves the exposure head 13 in the sub-scanning direction Y when the recording material 5 is not present at the exposure destination of the exposure head 13, and the exposure head 13 is stopped. , The recording material 5 is exposed in parallel with the main scanning direction X, and an image is recorded. Therefore, an image can be recorded in parallel to the recording material 5, and the recorded image The recording speed can be improved without impairing the image quality.

  In this embodiment, the outer surface scanning type image recording apparatus 1 that performs image recording while holding the recording material 5 on the outer peripheral surface of the rotary drum 4 has been described. However, the present invention may be applied to other types of image recording apparatuses. It is possible to apply. For example, an inner surface scanning type image recording apparatus having a cylindrical fixed drum capable of mounting a recording material such as a photosensitive material on the inner peripheral surface, and an exposure head that irradiates a light beam inside the fixed drum and performs image recording The present invention can also be applied to.

  That is, the inner surface scanning type image recording apparatus 41 includes, for example, a cylindrical fixed drum 43 to which a recording material 42 for forming an image can be mounted on the inner peripheral surface, and a fixed drum 43 as shown in FIG. And a plurality of exposure heads 44 arranged. The fixed drum 43 is a holding member for the recording material 42. The exposure head 44 is composed of a light emitter such as a semiconductor diode, for example, and includes an exposure light source 45 that irradiates the recording material 42 with a light beam L. On the exposure head 44 and on the optical path of the light beam L emitted from the exposure light source 45, a light reflecting element 47 is provided which is rotated about the central axis of the fixed drum 43 by a motor 46 as main scanning means. It has been. The rotation direction of the motor 46 is referred to as a main scanning direction X. Further, a lens 48 as an optical system for focusing the light beam L and forming an image on the recording material 42 is provided on the optical path of the light beam L and between the exposure light source 42 and the light reflecting element 47. Yes. An acceleration sensor 49 that measures the acceleration of the exposure head 44 is provided on the exposure head 44 and between the light reflecting element 47 and the lens 48. Further, inside the fixed drum 43, a linear motor 50 as a head moving mechanism that is composed of a plurality of magnets (not shown) and moves the exposure head 44 in the longitudinal direction of the fixed drum 43 (hereinafter referred to as the sub-scanning direction Y). A shaft-shaped stator 51 is provided so as to extend in the sub-scanning direction Y so as to be substantially parallel to the central axis of the fixed drum 43. A mover 52 constituting the linear motor 50 is installed at a position corresponding to the stator 51 of each exposure head 44. The mover 52 includes a hollow electromagnetic coil (not shown), and the stator 51 passes through a hollow portion of the mover 52. Since the configuration of the linear motor 50 is the same as that of the linear motor 19 shown in the embodiment, the description thereof is omitted. The exposure head 44 is provided with a linear encoder 53 as a head position detection mechanism for detecting the position of the exposure head 44 and the like. The linear encoder 53 is installed on the surface opposite to the surface on which the encoder scale 54 extending in the sub-scanning direction Y substantially parallel to the stator 51 and the exposure light source 45 of the exposure head 44 is provided. A light sensor (not shown) that irradiates the encoder scale 27 with light as the exposure head 44 moves and receives the reflected light to detect the position is provided. Further, each part of the apparatus is driven and controlled by a control unit (not shown).

In such an inner surface scanning type image recording apparatus 41, when image data is input from an external device, the control unit holds the recording material 42 on the inner peripheral surface of the fixed drum 43 based on this. At the same time, the control unit starts image recording by irradiating the exposure light source 45 with the light beam L. The light beam L emitted from the exposure light source 45 is reflected by the light reflecting element 47 and focused by the focusing action of the lens 48 in the optical path, and the recording material 42 mounted on the inner peripheral surface of the fixed drum 43 is exposed. The image is formed on the surface. Further, the light reflecting element 47 is rotated by the motor 46, and the light beam L is irradiated in the main scanning direction X along with the rotation of the light reflecting element 47, so that the recording material 42 is exposed. As a result, an image is recorded on the recording material 42 held on the fixed drum 43 by the exposure head 44.
When the exposure head 44 records a predetermined image along the main scanning direction X of the recording material 42, the control unit drives and controls the linear motor 50, and when the recording material 42 does not exist at the irradiation destination of the light reflecting element 47. Then, the exposure head 44 is moved to a predetermined position where the next image recording is performed in the sub-scanning direction Y. The position of the exposure head 44 in the sub-scanning direction Y is detected by light reception by an optical sensor. When the exposure head 44 moves to a predetermined position, the control unit detects the acceleration of the exposure head 44 by the acceleration sensor 49 and determines whether or not the exposure head 44 is stopped. When it is determined that the exposure head 44 is stopped, the light beam L is emitted from the exposure head 44 to the recording material 42. As a result, the light beam L is irradiated in a direction parallel to the main scanning direction X while the exposure head 44 is stopped. can do.

1 is a top view illustrating a schematic configuration of an image recording apparatus according to the present invention. 1 is a side view showing a schematic configuration of an image recording apparatus according to the present invention. It is a perspective view which shows schematic structure of the stator and movable element which concern on this invention. 1 is a perspective view showing a schematic configuration of an exposure head according to the present invention. It is a perspective view which shows schematic structure of the optical sensor which concerns on this invention. It is a block diagram which shows the control structure of the image recording apparatus which concerns on this invention. It is a perspective view which shows schematic structure of the modification of the image recording device based on this invention shown to embodiment.

Explanation of symbols

1,41 Image recording device 4 Rotating drum 5, 42 Recording material 13, 44 Exposure head 19, 50 Linear motor 25, 49 Acceleration sensor 33 Control unit 43 Fixed drum

Claims (3)

A holding member for holding the recording material;
An exposure head for exposing the recording material by irradiating the recording material with a light beam;
Main scanning means for relatively moving the recording material and the light beam so that the recording material is exposed along the main scanning direction by the light beam;
A moving mechanism for moving the exposure head in a sub-scanning direction orthogonal to the main scanning direction;
The moving mechanism is controlled to move the exposure head when the recording material is not present at the light beam irradiation destination, and the light beam is applied to the recording material when the exposure head is stopped. An image recording apparatus comprising: a control unit that controls the exposure head to irradiate. An acceleration sensor for detecting the acceleration of the exposure head;
The image recording apparatus according to claim 1, wherein the control unit detects whether or not the exposure head is stopped by the acceleration sensor.   The image recording apparatus according to claim 1, wherein the moving mechanism is a linear motor including a magnet as a stator and an electromagnetic coil as a mover.

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