JP3680554B2 - Exposure equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to exposure equipment, more particularly, it relates to an exposure equipment for exposing the recording medium by a light beam.
[0002]
[Prior art]
There is known an exposure apparatus that forms an image by exposing a recording medium while linearly guiding an optical unit that generates a light beam. As a drive mechanism for an optical unit used in the exposure apparatus, a method of rotating a screw and moving it straight, a method of moving a wire and moving it straight, and the like are known.
[0003]
There is also known an exposure apparatus that guides an optical unit that generates a light beam by an optical system having an imaging lens, and exposes a recording medium.
[0004]
[Problems to be solved by the invention]
However, in the case of the screw drive system as the drive mechanism of the optical unit, there is a problem that the drive structure is complicated, uneven screw pitch due to rotation is likely to occur, and is susceptible to vibration. In addition, the optical unit is generally heavy with a laser generator, a lens, a reflection mirror, and the like. Therefore, in order to move a heavy optical unit with high accuracy in the wire drive system, it is generally necessary to increase the wire diameter. However, when the wire diameter is increased, when the wire is wound around the pulley and moved, the cross section of the wire is crushed into an ellipse at the portion wound around the pulley, the movement load of the wire fluctuates, and the manner of crushing changes. As a result, the accuracy of the movement amount of the wire with respect to the unit rotation amount of the pulley is lowered. Further, an error occurs when the pulley is rotated by a pulse signal by a pulse motor to move the optical unit by a predetermined amount. Furthermore, when the optical unit having the imaging lens is tilted and the vertical and horizontal rattling occurs, there is a problem that the optical axis shift and the focus shift of the imaging lens are likely to occur.
[0005]
The present invention has been made in view of the above problems, an object of the first invention, simple and smoothly, quiet, exposure equipment further by accurately linear guide mechanism capable can accurately exposing a light beam in a storage medium Is to provide. A second object of the present invention is to provide an exposure apparatus capable of accurately exposing a light beam to a storage medium by a mechanism in which an optical error due to tilting, rattling or the like of an optical unit hardly occurs.
[0006]
[Means for Solving the Problems]
The above object can be achieved by any of the following means.
[0007]
(1) An optical unit that generates a light beam, a recording medium holding unit that has a cylindrical drum around which a recording medium to be exposed by the light beam is wound and fixed, holds and rotates the cylindrical drum, and the optical unit. A rectilinear guide mechanism that slides on the guide shaft parallel to the axis of the cylindrical drum and linearly guides, and a drive unit that drives the optical unit via a rectilinear guide mechanism by a flat metal belt; 2. The exposure apparatus according to claim 1, wherein the linear guide mechanism includes a cleaning member that cleans a sliding surface of the guide shaft based on movement of the slide member that slides on the guide shaft .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
Embodiments of the present invention will be described with reference to the drawings. As an embodiment, an exposure apparatus for producing a color proof for printing plate making by exposing a photosensitive material with a light beam by a laser will be described, but the present invention is not limited thereto.
[0011]
FIG. 1 is a configuration plan view of the exposure apparatus according to the embodiment, FIG. 2 is a front view of the main part of the configuration of the exposure apparatus of FIG. 1, and FIG. 3 is a side view of the configuration of the exposure apparatus of FIG.
[0012]
The exposure apparatus is mainly composed of a drive unit 701, a rectilinear guide mechanism 70, an optical unit 50, a recording medium holding unit 20, and the like. Each configuration will be described sequentially.
[0013]
First, as shown in FIGS. 1 and 3, the driving unit 701 is a unit that is driven by a metal belt 74 formed of a metal flat belt that is driven through pulleys 72 and 73 by rotation of a driving source. When the pulse motor 71 of the drive source fixed to the apparatus main body 11 rotates, the pulley 72 fixed to the rotating shaft also rotates, and the pulley 72 and the metal belt 74 hung on the pulley 73 are driven. The metal belt 74 is driven, and the mounting table 78 is driven straight through the connection portion 75 and the vibration isolation member 81. A servo motor can also be used as a drive source.
[0014]
The metal belt 74 is a flat metal belt, and for example, 301 stainless steel, 302 stainless steel, titanium, beryllium copper, or the like is preferable. The plate thickness of the metal belt is preferably about 0.025 mm to 0.5 mm. Moreover, the yield strength of the material is preferably 180 kg / mm ² (in the case of SUS301HY). Since the metal belt is lightweight and thin, high-precision positioning control can be easily performed. Compared to the screw drive system, the metal belt drive system does not have a sliding portion, so that the initial dimensions can be maintained for a long period of time, and does not require lubricating oil and is clean. In addition, since the metal belt is not driven by a gear, it can be guided straight with high accuracy without causing uneven rotation.
[0015]
Further, the driving means 701 exposes the recording medium F by the light beam 65 in the forward movement process of the metal belt 74, and easily changes the rotational speed of the pulse motor 71 in the backward movement process from the forward movement process. It can be returned at a high moving speed, and the exposure apparatus can be exposed at high speed.
[0016]
As shown in FIGS. 1 and 3, the linear guide mechanism 70 is mounted by sliding members 791 and 792 that slide on guide shafts 76A and 76B fixed to the apparatus main body 11 by driving by a driving means 701 using a metal belt. Guide the stand 78 straight. The sliding member 791 includes sliding members 791A and 791B.
[0017]
The guide shafts 76A and 76B are made of stainless steel, which has good workability and is easy to finish. Therefore, the optical unit 50 is guided with high accuracy. The guide shafts 76A and 76B are attached to a shaft fixing seat 77 and are finely adjusted by screws 77M and fixed. Further, in the linear guide mechanism 70, a sliding member 791 having a V-shaped groove on the guide shaft 76A side slides straight. Further, the sliding member 792 slides toward the guide shaft 76B side. The metal belt 74 is disposed on the guide shaft 76A side to facilitate driving. Instead of sliding members with the V-shaped grooves, two of the outer periphery of the bearing may be by Unishi Ru carried on the guide shaft in the V-shape.
[0018]
The vibration isolating method of the rectilinear guide mechanism will be described. As shown in FIG. It is fixed between the lower connecting portion 751. The vibration is transmitted from the driving means 701 to the optical unit 50 via the linear guide mechanism 70, thereby preventing the exposure position accuracy from being lowered by the light beam.
[0019]
Next, the cleaning of the guide shaft of the linear guide mechanism will be described. As shown in FIG. 2, a cleaning member 85 such as a nonwoven fabric is attached to the sliding member 791, and the sliding surface of the guide shaft 76A is cleaned by movement. Although the cleaning member 85 is fixed to the mounting table 78, it may be attached to the sliding member 791. Similarly, although not shown, a cleaning member for cleaning the sliding surface of the guide shaft 76B by the movement of the sliding member 792 is provided. The drive mechanism of the optical unit 50 constituted by the drive means 701 and the straight guide mechanism 70 is referred to as an optical unit drive mechanism.
[0020]
Next, as shown in FIGS. 1, 2, and 3, the optical unit 50 is linearly driven by the linear guide mechanism 70, converts an electrical signal of image information into a light beam 65, and the light beam 65 is applied to the recording medium F. Exposure. In the optical unit 50, an optical system 60 such as lasers 611, 612, and 613 and an imaging lens 64 is attached on an optical base 66, and an electrical signal of image information is converted into B (blue), G (green), Input to R (red) lasers 611, 612, and 613, respectively, and the light is reflected by the total reflection mirror 63 and the die lock mirror 62 to synthesize light, and is imaged by the imaging lens 64 to be converted into the light beam 65. Then, the recording medium F is exposed.
[0021]
The imaging lens 64 creates a light beam and irradiates the recording medium F. Further, a composite principal point 641 of the imaging lens is a composite principal point of the first principal point H1 and the second principal point H2 of the lens. As shown in FIG. 1, the composite principal point 641 is provided in the vicinity of the intersection between the center line 761A of the guide shaft 76A and the center position in the sliding direction of the sliding members 791A and 791B. The lens has an optical property that the optical axis does not deviate even if there is a shake around the synthetic principal point. Therefore, even if there is a swing around the intersection of the optical axis of the imaging lens 64 and the center line 761A when the optical unit fixed to the mounting table 78 is moved, it coincides with the composite principal point of the imaging lens. Does not cause misalignment.
[0022]
Next, as shown in FIG. 1, the recording medium holding unit 20 rotates the recording medium F that is a cylindrical drum 31 and is wound. More specifically, when the motor 41 fixed to the apparatus main body 11 rotates, the pulley 42 fixed to the rotation shaft of the motor rotates, and the pulley 45 and the belt 45 placed on the pulley 43 are driven, and the pulley 43 rotates. The cylindrical shaft 32 integrated with the pulley 43 supported by the bearing 33 rotates, and the cylindrical drum 31 fixed to the cylindrical shaft 32 rotates. A hole 47 is provided on the outer periphery of the cylindrical drum 31, and the recording medium F is sucked by the suction device 46 to bring the recording medium into close contact with the cylindrical drum 31. A rotary encoder 21 is installed integrally with the cylindrical shaft 32 and measures the rotational position of the cylindrical drum 31.
[0023]
(Description of operation)
Here, the main operation of the exposure apparatus will be described with reference to FIGS.
[0024]
First, the recording medium F is wound around the cylindrical drum 31 and fixed by being brought into close contact with the suction device 46. Here, the cylindrical drum 31 is rotated by the motor 41.
[0025]
The exposure apparatus receives an electrical signal of image information from an external device (not shown), processes the signal, and inputs a written image information signal to the lasers 611, 612, and 613, respectively. Thereafter, the optical unit 50 generates a light beam and exposes the recording medium F on the rotating cylindrical drum 31 to perform main scanning. On the other hand, the optical unit 50 is moved in parallel with the cylindrical drum shaft 32 by the linear guide mechanism having the metal belt 74 and sub-scanned by the light beam 65, and image information is transferred to the recording medium F by the main scanning and the sub-scanning of the light beam. Write. When the writing is completed, the rotation of the cylindrical drum 31 is stopped, the suction of the recording medium F is released, the recording medium F is taken out, and developed by a conventional developing device (not shown) to obtain a color proof. As described above, since the optical unit is moved by the straight guide mechanism using the metal belt, the straight guide of the optical unit can be made with high accuracy and high-precision exposure can be performed.
[0026]
(Embodiment 2)
Next, the vibration isolation of another linear guide mechanism in the embodiment will be described. FIG. 4 is a front view of another vibration isolation mechanism. An anti-vibration member 82 using an air spring is provided between the driving unit 701 and the linear guide mechanism 70. The vibration isolation member 82 is fixed between the upper connection member 752 and the lower connection portion 751 of the connection portion 75. Further, the optical unit 50 is fixed to the mounting table 78. As a result, vibration is transmitted from the driving means 701 to the optical unit 50 via the linear guide mechanism 70, and the exposure position accuracy due to the light beam is prevented from deteriorating.
[0027]
(Embodiment 3)
Next, the vibration isolation of another linear guide mechanism in the embodiment will be described. FIG. 5 is a front view of another vibration isolating mechanism. An anti-vibration member 83 is provided between the drive unit 701 and the linear guide mechanism 70. The vibration isolation member 83 is fixed between the upper connection member 752 and the lower connection portion 751 of the connection portion 75. Further, the optical unit 50 is fixed to the mounting table 78. As the vibration isolation member 83, for example, a vibration isolation member having a high vibration isolation effect such as Isolos, α-gel, and sorbosein is used. As described above, the vibration is transmitted from the driving unit 701 to the optical unit 50 through the linear guide mechanism 70 to prevent the exposure position accuracy by the light beam from being lowered.
[0028]
In the embodiment, a metal belt is put between two pulleys and one pulley is rotated by a motor and driven. For example, a metal belt is wound around one pulley and the tip of the metal belt is wrapped around the other pulley. The metal belt may be moved so that the metal belt is wound up by the pulley while being fixed.
[0029]
In the embodiment, laser light is used as the light source of the optical system. However, for example, an LED array may be used.
[0030]
In the embodiment, the light beam is formed by combining the B (blue), G (green), and R (red) light, but may be a monochromatic light beam, for example.
[0031]
Furthermore, in the embodiment, the recording medium is rotated and the optical unit is moved in a direction orthogonal to the rotation. For example, the recording medium may be linearly moved and the optical unit may be moved in the orthogonal direction. .
[0032]
【The invention's effect】
Since it comprised as mentioned above, there exist the following effects. According to the first aspect of the present invention, since the optical unit is moved by the rectilinear guide mechanism using the metal belt, the rectilinear guide can be moved with high accuracy and high image quality can be obtained. In addition, the cleaning member can prevent a decrease in accuracy due to dust on the guide shaft.
[0036]
According to the second aspect of the present invention, the vibration of the optical unit can be prevented, the moving accuracy of the optical unit is improved, and the image quality is improved.
[0037]
According to the third aspect of the present invention, highly accurate exposure using a light beam can be performed.
[Brief description of the drawings]
FIG. 1 is a configuration plan view of an exposure apparatus according to an embodiment.
2 is a front view of a main part of the configuration of the exposure apparatus in FIG. 1. FIG.
3 is a side view of the configuration of the exposure apparatus in FIG. 1. FIG.
FIG. 4 is a configuration front view of another vibration isolating mechanism of the embodiment.
FIG. 5 is a configuration front view of another vibration isolation mechanism of the embodiment.
[Explanation of symbols]
11 apparatus main body 20 recording medium holding means 31 cylindrical drum 32 cylindrical shaft 50 optical unit 64 imaging lens 641 combining principal point 65 light beam 701 driving means 72, 73 pulley 74 metal belt 70 rectilinear guide mechanisms 76A, 76B guide shaft 761A center line 78 Mounting base 791, 791A, 791B, 792 Sliding member 81, 82, 83 Anti-vibration member 85 Cleaning member F Recording medium

Claims (3)

An optical unit for generating a light beam, a recording drum holding means for holding and rotating the cylindrical drum around which a recording medium exposed by the optical beam is wound and fixed; and the optical unit for the cylindrical drum A rectilinear guide mechanism that slides on the guide shaft in parallel with the axis of the guide, and driving means that drives the optical unit via a rectilinear guide mechanism by a flat metal belt, and the rectilinear guide An exposure apparatus , wherein the mechanism includes a cleaning member that cleans a sliding surface of the guide shaft based on movement of a sliding member that slides on the guide shaft . 2. The exposure apparatus according to claim 1 , wherein a vibration isolating member for preventing vibration transmitted from the drive means to the linear guide mechanism is interposed between the drive means and the linear guide mechanism. Wherein the optical unit converts the electrical signal of the image information to the light beam, the exposure apparatus according to claim 1 or 2, characterized in that exposing the light beam to the recording medium.

Images