JP2007316536A - Optical scanner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform laser beam scanning with high recording accuracy without using an optical system for compensating focal length. <P>SOLUTION: The optical scanner is equipped with a plurality of laser light source units 11-15 for emitting a laser beam and also with a scanning means which is arranged above the transporting path of a heat-sensitive recording medium 16, which, while reflecting a laser beam from each laser light source unit by a reflection member 17, transfers the reflection member 17 orthogonally to the transporting direction A of the heat-sensitive recording medium, while maintaining the optical path length to the heat-sensitive recording medium 16 for each laser beam to be constant, and which simultaneously scans each laser beam orthogonally to the transporting direction relative to the heat-sensitive recording medium. For example, a laser beam from the laser light source is made incident to the reflection member 17, orthogonally to the transporting direction A of the heat-sensitive recording medium and from above with the incidence angle at an elevation of 45°, and then, the reflection member is transferred vertically/obliquely along the extension of the incidence angle 45° of the laser beam; thus, the optical path length is maintained to bb constant. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical scanning device that scans a laser beam to record information on a recording medium.

Conventionally, as an optical scanning device that records information in a non-contact manner by irradiating a recording medium such as a reversible thermosensitive recording medium, laser light from a laser light source is applied to a scanning mirror via an optical fiber and a lens head. A laser beam that scans a recording medium transported on a plane by the rotation of the scanning mirror is known (see, for example, Patent Document 1).
JP 2002-113889 A

However, in the case where the laser beam is scanned by rotating the scanning mirror with respect to the recording medium transported on the flat surface in this way, the optical path length when the laser beam scans the recording medium is different between the center and the side portion. In order to increase the accuracy, there is a problem that an expensive focal length correction optical system using an fθ lens or the like must be used.
Accordingly, the present invention provides an optical scanning device that can perform laser light scanning with high recording accuracy without using a focal length correction optical system.

  The present invention provides a laser light source that emits laser light and a recording medium conveying path, and reflects the laser light from the laser light source with a reflecting member while the reflecting member passes the optical path length of the laser light to the recording medium. Is provided with scanning means for moving the laser beam in a direction orthogonal to the conveyance direction by moving the laser beam in a direction orthogonal to the conveyance direction of the recording medium.

  According to the present invention, it is possible to provide an optical scanning device capable of performing laser beam scanning with high recording accuracy without using a focal length correction optical system.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
As shown in FIG. 1, five laser light source devices 11, 12, 13, 14, and 15 are placed above a transport path of a reversible thermosensitive recording medium 16 as a recording medium in the transport direction A of the thermosensitive recording medium 16. Are spaced apart from each other at a predetermined interval.

  A long reflecting member 17 is arranged in parallel with the conveying direction A of the thermal recording medium 16 along the arrangement of the laser light source devices 11 to 15, and the reflecting surface thereof is relative to the recording surface of the thermal recording medium 16. Are arranged vertically.

  As shown in FIG. 2, the laser light source device 11 includes a laser light source 11a, a collimator lens 11b that converts the laser light from the laser light source 11a into parallel light, and the laser light from the collimator lens 11b as the reflection member. A condensing lens 11c that condenses light on the 17 reflecting surfaces. Although only the laser light source device 11 has been described in FIG. 2, the configurations of the other laser light source devices 12 to 15 are the same.

  Each of the laser light source devices 11 to 15 has a laser beam that is perpendicular to the transport direction A of the thermal recording medium 16 with respect to the reflection surface of the reflection member 17 and has an incident angle of 45 °. It arrange | positions so that it may inject from upper direction.

  The reflection member 17 is extended along an extending direction of an incident angle of 45 ° of the laser light from each of the laser light source devices 11 to 15 in a state where the reflection surface is maintained perpendicular to the transport surface by a driving device described later. As shown by the arrow B in the figure, the movement is controlled up and down.

  That is, as shown in FIG. 2, when the reflecting member 17 is at the highest position (the position of the solid line in the figure), the laser beam reflected by the reflecting surface is perpendicular to the transport direction A of the thermal recording medium 16. Is located at one end P1 of the print range in the main scanning direction. Further, when the reflecting member 17 is at the lowest position (dotted line position in the figure), the laser beam reflected by the reflecting surface is located at the other end P2 of the print range in the main scanning direction on the thermal recording medium 16. Then, the reflection member 17 moves obliquely up and down between the highest position and the lowest position as shown by the arrow B in the figure, thereby scanning the laser beam in the print range and printing one scan line. It is like that.

  As the reversible thermosensitive recording medium 16, as shown in FIG. 3, a thermolite TRF33TA (Mitsubishi) in which a rewrite layer 162 is formed on a PET (polyethylene terephthalate) layer 161 and a protective layer 163 is formed thereon. A paper manufacturing company) is used as a base, and a photothermal conversion layer 164 is formed on the base.

The photothermal conversion layer 164 is made of a material obtained by mixing a near-infrared absorbing dye (SDA5688: manufactured by HWSANDS, λmax = 842 nm): 0.2 parts by weight, polyester resin: 10 parts by weight, isocyanate: 0.1 parts by weight. It is applied on the base with a wire bar and formed to a dry film thickness of 2 μm. The thermal recording medium 16 has a width in the main scanning direction of 110 mm.
As the laser light source of each of the laser light source devices 11 to 15, a laser light source that emits laser light having a wavelength of 830 nm and an output of 1 W in accordance with the absorption wavelength of the near-infrared absorbing dye is used. Then, the heat-sensitive recording medium 16 is irradiated with laser light, and the light applied to the light-to-heat conversion layer 164 is converted into heat, and color is developed by transferring heat to the rewrite layer 162 under the protective layer 163. By this color development, recording is performed dot by dot on the thermal recording medium 16. Further, the color can be erased by changing the heat applied to the rewrite layer 162. In other words, the reversible thermosensitive recording medium 16 can be colored and decolored depending on the state of heat applied to the rewrite layer 162, and can record and erase information repeatedly.

  FIG. 4 is a block diagram showing the configuration of the control unit. A conveyance path 18 including a conveyance belt is driven by a conveyance device 19 to convey the thermal recording medium 16 placed on the conveyance path 18. The laser light source 11a of the laser light source device 11 is driven by a laser driver 20 to emit laser light on which recording information is placed. Similarly, the laser light sources of the other laser light source devices 12 to 15 are each driven by a laser driver so as to emit laser light with recorded information.

  The reflecting member 17 is driven by a driving device 21 so as to reciprocate in a slanting vertical direction as indicated by an arrow B in FIG. That is, as shown in FIG. 5, the driving device 21 is composed of a single-axis robot 23 incorporating an AC servo motor 22, and the single-axis robot 23 is incident on the laser beam incident angle from the laser light source devices 11-15. It is installed at the same angle as 45 °. Then, the single-axis robot 21b reciprocates the slider 24 along the axis as shown by the arrow in the figure by the AC servo motor 22 so that the reflecting member 17 attached to the slider 24 has its reflecting surface on the reflecting surface. While maintaining a perpendicular state with respect to the recording medium 16, it is reciprocated obliquely up and down at the same angle as the incident angle of 45 °. The reflection member 17 and the driving device 21 constitute scanning means.

  Further, a control device 25 having a microprocessor or the like is provided, and the control device 25 controls the transport device 19, the laser drivers 20,.

  In such a configuration, the transport device 19 drives the transport path 18 to transport the thermal recording medium 16 and stop it at the print start position. In this state, each laser driver 20,... Drives the laser light sources 11a,... Of each laser light source device 11-15, and the drive device 21 operates the slider 24 of the single-axis robot 23 to move the reflecting member 17 from the highest position. Start moving towards the lowest position.

  Laser light from the laser light sources of the laser light source devices 11 to 15 is incident on the reflecting member 17 at an incident angle of 45 ° from a direction orthogonal to the conveyance direction A of the thermal recording medium 16 and is reflected by the reflecting surface. Irradiated onto the thermal recording medium 16.

  When the reflecting member 17 moves, the laser beam is scanned from one end to the other end of the print range in the main scanning direction of the thermal recording medium 16. In this way, one scanning line is printed on the thermal recording medium 16 by each of the laser light source devices 11-15.

  When printing for one scanning line is completed, the transport path 18 is driven by the transport device 19 and the thermal recording medium 16 is transported for one scanning line. That is, the thermal recording medium 16 is conveyed in the sub-scanning direction by one scanning line. When the conveyance is finished, the laser drivers 20,... Drive the laser light sources of the laser light source devices 11 to 15 again, and the drive device 21 operates the slider 24 of the single-axis robot 23 to turn the reflecting member 17 to the opposite side this time. Start moving from the lowest position to the highest position.

  When the reflecting member 17 moves, the laser beam is scanned from the other end of the print range in the main scanning direction on the thermal recording medium 16 toward one end. In this way, each laser light source device 11-15 prints the next one scanning line on the thermal recording medium 16, and the printing by one reciprocating scanning of the laser light is completed.

  Therefore, if the interval in the sub-scanning direction of the scanning lines by the laser beams of the laser light source devices 11 to 15 is, for example, 6 lines, the three reciprocating scans of the laser beams by the three reciprocating movements of the reflecting member 17 are completed. The space between the scanning lines in the sub-scanning direction by the laser light from the light source devices 11 to 15 is filled.

  When the three reciprocating scans of the laser beam are completed, the transport path 18 is driven by the transport device 19 and transports the thermal recording medium 16 by a distance of (5 × 6 + 1) scan lines, that is, 31 scan lines. Thus, the first scanning line by the laser light source device 11 is positioned at the line position next to the scanning line last scanned by the laser light from the laser light source device 15. Then, the reciprocal scanning of the next 30 scanning lines by the laser light source devices 11 to 15 is started.

  As described above, since printing is performed by simultaneously scanning the laser beam by five scanning lines using the five laser light source devices 11 to 15, printing on the thermal recording medium 16 can be performed at high speed.

  Further, the laser light from each of the laser light source devices 11 to 15 is incident on the reflecting member 17 at an incident angle of 45 ° from the direction orthogonal to the conveying direction of the thermal recording medium 16, and the reflecting member 17 is The thermal recording medium 16 is scanned with laser light by reciprocating the reflecting surface in the direction of arrow B along the incident angle while maintaining the reflecting surface perpendicular to the transport surface. As a result, the optical path length of the laser light from each of the laser light source devices 11 to 15 is constant at any position from one end to the other end of the print range in the main scanning direction of the thermal recording medium 16. Accordingly, the laser beam can be focused at any position within the printing range without using the focal length correction optical system, and the recording accuracy by the laser beam can be improved. In addition, since the focal length correcting optical system having an expensive and complicated configuration is not used, the configuration can be simplified and the economy can be improved.

(Second Embodiment)
In this embodiment, as shown in FIG. 6, an angle changing device 26 that changes the angle of the reflecting member 17 is provided, and the angle changing device 26 is controlled by the control device 22. The angle changing device 26 is attached to the slider 24 of the single-axis robot 23 in the same manner as the reflecting member 17.

Further, the conveying device 19 drives the conveying path 18 to convey the reversible thermosensitive recording medium 16 at a predetermined speed while the laser light is emitted from each of the laser light source devices 11 to 15 and the reflecting member 17 is moved. To continue. Other configurations are the same as those of the first embodiment described above.
As shown in the side view of FIG. 7 (a) and the plan view of FIG. 7 (b), the angle changing device 26 spans a belt 33 between a pair of gears 31 and 32. The rotation is transmitted to the other gear 32 through the belt 33 by being rotationally driven at 34. The back side of the reflecting member 17 opposite to the reflecting surface of the reflecting member 17 is fixed to the other gear 32 by using a fixing member 35.

  The angle changing device 26 rotates a gear 31 by a stepping motor 34 and transmits this rotation to the other gear 32 by a belt 33. Then, according to the rotation angle of the gear 32, the reflection member 17 tilts the reflection surface from a state parallel to the conveyance direction of the thermal recording medium 16. The gear 32 is rotatably supported by a connection shaft 36.

  That is, when the angle changing device 26 scans the laser beam by moving the reflecting member 17 from the highest position to the lowest position as shown by an arrow B1 in the drawing, as shown in FIG. The angle of the reflection member 17 is changed so that the front end of the reflection member 17 on the downstream side in the conveyance direction (arrow A direction) is gradually opened according to the conveyance speed of 16.

  Further, as shown in FIG. 9, the angle changing device 26 moves the reflecting member 17 from the lowest position to the highest position as shown by an arrow B2 in the figure, and scans the laser beam. The angle of the reflecting member 17 is changed so that the rear end of the reflecting member 17 on the upstream side in the conveying direction (arrow A direction) gradually opens according to the conveying speed of 16.

  In such a configuration, printing can be performed by scanning the laser beam while transporting the thermal recording medium 16 at a predetermined speed. That is, when the laser beam is scanned by transporting the thermal recording medium 16 in the direction of arrow A as shown in FIG. 10 without changing the angle of the reflecting member 17, the main scanning direction is shown in FIG. In contrast, the laser beam is scanned obliquely, and printing cannot be performed.

  On the other hand, when the angle of the reflecting member 17 is changed as shown in FIGS. 8 and 9 according to the conveyance speed of the thermal recording medium 16 using the angle changing device 26, as shown by the solid line arrow in the figure. Laser light can be scanned in a direction orthogonal to the carrying direction A, that is, parallel to the main scanning direction, and printing can be performed.

  In this way, printing can be performed by scanning the laser beam while transporting the thermal recording medium 16 at a predetermined speed, so that higher-speed printing can be realized. In other respects, the same effects as those of the above-described embodiment can be obtained.

  For example, while the thermal recording medium 16 is conveyed at a conveyance speed of 0.32 mm / sec, the reflection member 17 is reciprocated at a speed of 320 mm / sec, and the angle of the reflection member 17 is varied in synchronization with the conveyance speed. Appropriate laser beam scanning in the main scanning direction with respect to the recording medium 16 was realized.

  In each of the above-described embodiments, the case where five laser light sources are used to simultaneously scan five laser lights is described. However, the present invention is not limited to this, and one laser light source is used. Even if it is what was used, the thing using several laser light source devices other than five may be used.

  In this embodiment, the recording medium is applied to a recording medium that uses a reversible thermal recording medium that can be written and erased. However, the present invention is not limited to this, and the thermal recording medium can be written only once. The present invention can also be applied to a recording medium using the photosensitive surface of the photosensitive drum as a recording medium.

1 is a perspective view showing a schematic configuration of an optical scanning device according to a first embodiment of the present invention. The figure for demonstrating the laser beam scanning by the optical scanning device concerning the embodiment. Sectional drawing which shows the structure of the reversible thermosensitive recording medium used in the embodiment. FIG. 3 is a block diagram showing a control configuration of the optical scanning device according to the embodiment. The figure which shows the structure of the drive device which concerns on the same embodiment. The block diagram which shows the control structure of the optical scanning device which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the angle change apparatus of the embodiment, (a) is a side view, (b) is a top view. The top view which shows the angle change state of a reflection member when a reflection member moves to a low position from a high position in the embodiment. The top view which shows the angle change state of a reflection member when a reflection member moves from a low position to a high position in the same embodiment. The perspective view which compares the scanning line on a thermal recording medium when scanning a laser beam, conveying a thermal recording medium using the reflective member which does not change an angle with the reflective member in the embodiment, and shows.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11-15 ... Laser light source device, 11a ... Laser light source, 16 ... Reversible thermosensitive recording medium, 17 ... Reflecting member, 19 ... Conveyance device, 20 ... Laser driver, 21 drive device.

Claims (4)

A laser light source for emitting laser light;
The recording medium is disposed above the conveyance path of the recording medium, reflects the laser light from the laser light source with a reflecting member, and maintains the optical path length of the laser light to the recording medium while maintaining the reflection path of the recording medium. An optical scanning device comprising: scanning means for moving in a direction orthogonal to a conveyance direction and scanning the laser beam in a direction orthogonal to the conveyance direction with respect to the recording medium. A plurality of laser light sources for emitting laser light;
The recording medium is disposed above the conveyance path of the recording medium, reflects the laser light from each laser light source with a reflecting member, and keeps the optical path length of each laser light to the recording medium constant while the recording member performs the recording. An optical scanning apparatus comprising: a scanning unit that moves in a direction orthogonal to a medium conveyance direction and simultaneously scans the recording medium in a direction orthogonal to the conveyance direction with respect to the recording medium. The laser light source makes the laser light incident on the reflecting surface of the reflecting member at an incident angle of 45 ° from a direction perpendicular to the recording medium conveyance direction,
The scanning means arranges the reflecting member so that the reflecting surface thereof is perpendicular to the recording surface of the recording medium, and moves the reflecting member obliquely along the incident angle direction of the laser beam. The optical scanning device described.   The scanning means includes an angle changing device that varies the angle of the reflection surface of the reflecting member with respect to the conveyance direction of the recording medium in synchronization with the conveyance speed of the recording medium, and emits laser light without stopping conveyance of the recording medium. 4. The optical scanning device according to claim 1, wherein scanning is performed.

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