JPS6258770A - Optical beam scanner - Google Patents

Abstract

PURPOSE:To simplify the optical system in the titled scanner by applying sub scanning while a scanning sheet is fixed so as to miniaturize the entire scanner in the sub scanning direction especially, using a sub scanning reflection mirror to apply the sub scanning and forming the scanning sheet in a circular-arc face. CONSTITUTION:After a light beam 2 irradiated from a laser light source 1 is made incident on a modulator 6 and modulated, the beam is deflected by a rotary polygon mirror 3 being a main scanning optical deflector turned in the arrow A, transmitted through an image forming lens 4 and reflected in a long sub scanning reflection mirror 10 turned at a low speed in the arrow C and prolonged in the main scanning direction. A sheet form recording medium 5 such as print paper is supported in a circular-arc face form by a recording medium support means 11 having a circular-arc form support face 11a. The center axis of the circular-arc face formed in the recording medium 5 is made nearly coincident with the turning shaft of the sub scanning mirror 10. The light beam 2 deflected by a rotary polygon mirror 3 applies main scanning on the recording medium 5 in the arrow B. The main scanning line formed on the recording medium 5 by the light beam 2 is moved gradually in the arrow D by the turning of the sub scanning mirror to apply sub scanning.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a light beam scanning device that scans a light beam using an optical deflector. The present invention relates to a scanning device.

<Technical Background and Prior Art of the Invention> Conventionally, light beam scanning devices that deflect a light beam using an optical deflector and scan a scanning sheet relatively two-dimensionally have been used in various types of scanning recording scanning and scanning reading devices. 1, etc., is widely used. Two-dimensional scanning of the light beam in these light beam scanning devices involves deflecting the light beam with an optical deflector to cause it to main scan the scanning sheet, and also moving the light beam and the scanning sheet relative to each other in the main scanning direction. This is done by moving in the sub-scanning direction which is substantially perpendicular to.

However, in the conventional apparatus, various problems have arisen, such as the apparatus becoming larger due to the means for performing the sub-scanning, and the optical system becoming complicated and expensive. Hereinafter, problems with the conventional light beam scanning device will be explained with reference to FIGS. 3 and 4.

In the light beam scanning device shown in FIG.
A light beam 102 emitted from the light beam 102 enters a rotating polygon mirror 103, which is an optical deflector, and is reflected and deflected as the polygon mirror rotates in the direction of the arrow.

The light beam reflected by the rotating polygon mirror 103 passes through an fθ lens 104, which is an imaging lens, provided on the optical path, and then main scans the scanning sheet 105 in the direction of arrow B. The scanning sheet 105 is scanned in the main scanning direction as the rotating drum 10G rotates while being held between a rotating drum 106 rotating in the direction of arrow C and a pair of rollers 107A and 1107B provided on the rotating drum. Sub-scanning is performed by being conveyed in the direction indicated by the arrow at right angles. Therefore, the light beam 102 repeats main scanning in the direction of the arrow B on the scanning sheet 105 that is conveyed (sub-scanned) in the direction of the arrow.
105 is scanned two-dimensionally.

However, in the above-mentioned apparatus, sub-scanning is performed by moving the scanning sheet, but in order to suppress load fluctuations to the motor 108 during sub-scanning as much as possible and to prevent uneven sub-scanning from occurring, the In this way, it is necessary to provide a space in which one scanning sheet can be placed, by arranging support stands 109 and 110 for supporting the scanning sheet 105 before and after the scanning position by the light beam.

Therefore, the above device requires a space with a length of at least two scanning sheets in the sub-scanning direction.
i! There is a problem that the entire LIT becomes large.

In addition, the rotating drum 106 that conveys the scanning sheet has a width larger than the width of the scanning sheet in order to stably convey the scanning sheet, and the motor 108 that rotates the rotating drum 106 further has a width larger than the width of the scanning sheet. Since it is installed in the width direction of the rotating drum, the above-mentioned device is also large in the main scanning direction.

Furthermore, while transporting the scanning sheet, highly accurate scanning is performed on the scanning sheet! Therefore, it is necessary to strictly control the motor so that the scanning sheet [- can be transported at a constant speed in the correct direction with high precision, and a high-precision motor that can perform the above control is expensive. Therefore, there is also the problem that the cost of the entire device increases significantly. In addition, in order to stably convey the scanning sheet, the roller 107A,
107B is essential, but because of the provision of these rollers, it is not possible to scan both ends of the scanning sheet in the sub-scanning direction. For example, if the apparatus is a light beam recording device, both ends cannot be scanned. I can't meet the request to make it Black Edge.

As described above, a light beam scanning device that performs sub-scanning by conveying a scanning sheet has various problems. In view of these problems, a device that performs sub-scanning without moving the scanning sheet has also been proposed.Hereinafter, a light beam scanning device with a fixed scanning sheet will be explained with reference to FIG. do. Note that the same parts as those in the apparatus shown in FIG. 3 are given the same numbers and their explanations will be omitted.

The apparatus shown in FIG. 4 includes a rotating polygon mirror 103 that rotates in the direction of the arrow to reflect and deflect the light beam 102 and performs main scanning on the scanning sheet 111 in the direction of the arrow B, and a rotating polygon mirror 103 that rotates in the direction of the arrow C to perform main scanning in the direction of the arrow C. A sub-scanning galvanometer mirror 112 is provided which reflects and deflects the light beam so that the main scanning line moves in the direction of the arrow on the scanning sheet 111 which is fixed at a predetermined position. That is, the sub-scanning galvanometer mirror 112 rotates once in the direction of arrow C, which is a direction substantially perpendicular to the main scanning direction of the light beam, at a low speed while scanning one scanning sheet. The light beam 102 is caused to scan the entire surface of the scanning sheet 111 in two-dimensional directions by the rotating polygon mirror 103 and the sub-scanning galvanometer mirror 112.

When the mj scanning galvanometer mirror 112 finishes scanning one scanning sheet, it returns to its original position and prepares for scanning the next scanning sheet.

Also, between the sub-scanning galvanometer mirror 112 and the scanning sheet 111 is an fθ lens 113 which is an imaging lens.
is provided, and this fθ lens is a rotating polygon mirror 103
The light beam reflected and deflected at a constant angular velocity by the sub-scanning galvanometer mirror 112 is caused to linearly scan at a constant velocity on the flat scanning sheet surface.

By the way, in the above-mentioned apparatus, in order to make the light beam deflected by the rotating polygon mirror 103 and take a spread optical path enter the reflecting surface of the relatively small sub-scanning galvanometer mirror, the optical path of the light beam is once focused. A relay lens 114 is provided that adjusts the optical path of the light beam so that the light beam passes through the convergence position and spreads again by reproducing the deflection by the rotating polygon mirror. The sub-scanning galvanometer mirror is arranged at a position where the optical path of the light beam is focused by the relay lens 114, and the light beam is focused by the relay lens 11.
4, all of the beams are made incident on the sub-scanning galvanometer mirror and deflected. After being reflected and deflected by the sub-scanning galvanometer mirror, the light beam passes through the rotating polygon mirror 10.
Since the optical path is widened again at an angle corresponding to the deflection of 3, a main scanning line of the required length can be obtained on the scanning sheet 111.

However, since the apparatus shown in FIG. 4 is provided with the relay lens 114 in addition to the imaging lens 113 as described above, the optical system becomes complicated, and it is difficult to achieve sufficient miniaturization of the apparatus. I can't.

There is also the problem that the provision of the relay lens increases the number of optical elements, increasing manufacturing costs.

(Object of the Invention) The present invention has been made in view of the above problems, and sub-scanning is performed without moving the scanning sheet, and various problems such as an increase in the size of the device due to the movement of the scanning sheet. It is an object of the present invention to provide a light beam scanning device which can eliminate the above problems, and further reduce the size of the entire device and reduce manufacturing costs by performing scanning without using a complicated optical system equipped with expensive optical elements. This is the purpose.

(Structure of the Invention) The light beam scanning device of the present invention includes: a main scanning optical deflector that is provided on the optical path of a light beam emitted from a beam light source and deflects the light beam; an imaging lens disposed on the optical path of the deflected light beam; a mirror disposed on the optical path of the light beam that has passed through the imaging lens and reflecting the light beam with a reflective surface; a sub-scanning mirror that rotates approximately as a rotation wheel around the intersection of a plane containing the optical path of the light beam that has passed through the imaging lens or a plane parallel to the plane and a plane perpendicular to the optical axis of the imaging lens; A first feature of the present invention is that it includes a scanning sheet holding means that holds the scanning sheet in an arcuate shape having a central axis that substantially coincides with the drive axis of the sub-scanning mirror.

That is, in the light beam scanning device of the present invention, since the scanning sheet is fixed by the scanning sheet holding means, as in the case where the scanning sheet is conveyed to perform sub-scanning,
There is no need to make the device larger in the sub-scanning direction,
The entire device can be made compact. In addition, the light beam reflected by the main scanning optical deflector passes through the main scanning imaging lens and is directly reflected by the sub scanning mirror for one scan, so there is no need to provide a relay lens etc. The system becomes simple and inexpensive. Note that the light beam whose optical path has been widened by being deflected by the main scanning optical deflector is incident on the sub-scanning mirror, so due to the design of the optical system, it must be a long mirror that extends in the main scanning direction. preferable.

By the way, as mentioned above, in the apparatus of the present invention, the scanning sheet is held in an arcuate shape by the scanning sheet holding means, so the scanning sheet can be reliably carried into this arcuate holding position and the scanning sheet can be accurately positioned. However, it is necessary to reliably transport the scanning sheet from the holding position. Therefore, the apparatus of the present invention includes a carrying means that is provided near one end of the scanning sheet holding means and carries the scanning sheet i to a cup at a predetermined position on the scanning sheet holding means, and a carrying means that is provided near the other end of the scanning sheet holding means. and a sheet discharging means provided near the one end of the scanning sheet holding means, which pushes the rear end of the scanning sheet to move the carried-in scanning sheet toward the predetermined position; A second feature of the present invention is that it includes a scanning sheet delivery plate that can move the scanning sheet at a predetermined position to a position where the leading end of the scanning sheet is gripped by the delivery means.

(Embodiment) Hereinafter, embodiment g of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an outline of a light beam recording device which is an embodiment of the light beam scanning device of the present invention.

A light beam 2 emitted from a laser light source 1 enters a modulator 6 which is modulated by a modulator drive circuit 7 based on a signal emitted from an image signal output circuit 8 that outputs an image signal. The light is incident on the rotating polygon mirror 3, which is a main scanning optical deflector, and is deflected in the direction of the arrow. As the laser light source 1, in addition to a He-Ne laser, an Ar laser, etc., a laser light source formed by a combination of a semiconductor laser and a beam shaping optical system is used. Furthermore, when using a laser light source capable of direct modulation such as a semiconductor laser, the modulator 6 is not particularly provided in the optical path of the light beam 2, and the laser light source is directly controlled to modulate the light beam. You can also do that. In addition to the rotating polygon mirror described above, other types of optical deflectors such as a galvanometer mirror and an acousto-optic optical deflector (80D) may be used as the main scanning optical deflector.

The light beam deflected by the rotating polygon mirror 3 passes through an imaging lens 4 such as an fθ lens provided on the optical path, and then is driven by a motor 9 to rotate at a low speed in the direction of arrow C. Long sub-scanning reflective mirror 1 extending in the scanning direction
0 and is reflected by the reflective surface 10a. Further, below this sub-scanning mirror 10, on the optical path of the light beam reflected by the sub-scanning mirror, a sheet 1-shaped recording medium 5 such as a photographic film or photographic paper is placed on an arc-shaped holding surface. It is held in an arcuate shape by a recording medium holding means 11 having an angle of +1a. This holding means 11 can be used, for example, to bend a plate-shaped object,
It is formed by integral molding using synthetic resin or the like. Further, the central axis of the circular arc surface formed by the recording body 5 substantially coincides with the rotation axis of the sub-scanning mirror 10.

When the recording medium 5 is held on the recording medium holding means 11 as described above, the light beam 2 is deflected by the rotating polygon mirror 3.
performs main scanning on the recording medium 5 in the direction of arrow B. The imaging lens 4 converges the light beam 2 onto a recording medium 5, and deflects the light beam deflected at a substantially constant angular velocity by the rotating polygon mirror 3 onto the recording medium 5, which is flat in the main scanning direction, at a substantially constant velocity. This is a lens that allows scanning. Further, the sub-scanning mirror 10
is lowered in the direction of arrow C with the intersection of a plane containing the optical path of the light beam passing through the imaging lens 4 or a plane parallel to the plane and a plane perpendicular to the optical axis of the imaging lens 4 as the rotation axis. It rotates at a high speed, and desirably, the reflection position of the light beam 2 on the reflecting surface 10a and the rotation axis coincide with each other. Note that the rotation axis of this sub-scanning mirror may be located at a position slightly shifted from the above-mentioned reflection position within a range that does not cause a problem in terms of scanning accuracy of the light beam, such as the center position of the mirror in the thickness direction.

This sub-scanning mirror 10 rotates in the direction of the arrow C by a predetermined angle sufficient for the light beam to scan the entire surface of the recording medium while recording image information on one recording medium. By the rotation of this sub-scanning mirror, the main scanning line formed by the light beam 2 on the recording medium 5 is gradually moved in the direction of the arrow, thereby performing sub-scanning. Therefore, the light beam 2 is caused to two-dimensionally scan the entire surface of the recording medium by the rotating polygon mirror 3 and the sub-scanning mirror 10.

As described above, when the sub-scanning mirror 10 rotates by a predetermined angle at a predetermined speed and the necessary image information is recorded over the entire surface of the recording medium, the sub-scanning mirror 10 rotates in the rotation direction. The recording medium is rotated in the opposite direction, or further rotated in the rotational direction to complete one rotation, and returned to the initial position in preparation for recording on the next recording medium. In this implementation, as shown in FIG. 1, a photodetector 12 is attached on the recording medium holding means 11, and the photodetector 12 detects a light beam to determine the image recording scanning start position. It has become. That is, by rotating the sub-scanning mirror 10 from the initial position in the direction of arrow C, it is detected that the light beam has reached the end of the recording medium 5, and at this point, the light modulator 6 is activated based on the image signal. Then, the light beam 2 is modulated and image recording on the recording medium 5 is started.

As described above, in the apparatus of the present invention, DI reverse scanning is performed by fixing the recording medium and moving the light beam by rotating the sub-scanning mirror 10, so compared to the case where the recording medium is moved. , the size of the device in the sub-scanning direction can be reduced to about half. In addition, the sub-scanning mirror 10 is replaced with the above-mentioned method 7) l! Even when the sub-scanning mirror 1o is long in the main scanning direction as in the i embodiment, the length of the sub-scanning mirror 1o in the main scanning direction is long enough to allow the incidence of the light beam. Often, it is sufficient that the length is shorter than the main scanning line on the recording medium, so even if the DJ scanning mirror 10 and the motor 9 are combined, the length is shorter than the length of the recording medium holding means in the main scanning direction. The apparatus of the present invention is also compact in the main scanning direction. Note that the sub-scanning mirror 10 does not necessarily have to be long if it can be placed sufficiently close to the main-scanning optical deflector, and its shape also allows it to rotate around the above-mentioned rotating wheel. However, it may have any shape as long as it allows the light beam 2 to be incident without omission. Furthermore, since the motor 9 that drives the sub-scanning mirror 10 does not undergo load fluctuations, it is easy to control, and a relatively inexpensive motor can be used. Furthermore, the sheet holding means 1
The recording medium 5 held at 1 is irradiated with a light beam from the front end to the rear end in the sub-scanning direction so that recording can be performed on the entire surface of the recording medium.
It is also possible to make it black. Note that depending on the type of recording medium, the recording medium 5 may be attached to the holding surface 1 of the recording medium holding means 11.
1a and if it is difficult to maintain an arcuate shape, a suction means may be provided in the recording medium holding means 11 to suction the recording medium onto the holding surface 11a.

Furthermore, in the apparatus of the present invention, as described above, the sub-scanning mirror 10 is provided which allows all of the light beam 2 deflected by the main-scanning optical deflector 3 to enter, so that the optical path of the light beam 2 is adjusted. Since there is no need to provide a relay lens or the like, the optical system is simplified, the device becomes more compact, and the manufacturing cost can be reduced.

By the way, as described above, in the apparatus of this embodiment, the recording medium 5 is held in a circular arc shape at a predetermined position on the holding surface 11a by the recording medium holding means 11. Therefore, prior to scanning with the light beam, the recording medium 5 is reliably carried along the arc-shaped holding surface, and is accurately positioned at a predetermined position on the holding surface. It must be carried out reliably along the surface. Therefore, the above-mentioned apparatus is provided with a recording medium carrying-in means, a carrying-out means, and a positioning means. Each of the above means will be explained below with reference to FIGS. 1 and 2.

A pair of carry-in rollers 13Δ, 13B, which are means for carrying in the record body, are provided near one end of the marine record holding means 11. These carry-in rollers 13Δ, 13B, when carrying in recording bodies, suck the recording bodies 5 one by one from the magazine 14 in which a plurality of recording bodies 5 are stored, as shown in FIG. After that, the recording medium 5 is guided by the guide plate 15 and falls, and the recording medium 5 is grasped and rotated in the direction of the arrow.
is carried in along the holding surface 11a.

The carry-in rollers 13A, 13B feed the recording medium in the direction of arrow F1 by their rotation, and move the recording medium 5 to a predetermined position on the holding surface 11a where the recording medium 5 is to be held, as shown in FIG. Transport it to the front.

The recording medium 5 thus conveyed to the front of the predetermined position is
A rotating shaft 1 is provided near one end of the recording medium holder 8211 (as shown in FIG.
It is moved to a predetermined position by a recording body sending-out plate 19 fixed to the recording body 8 . That is, as shown in FIG. 2(a), the recording body 5 is
Is it a holding surface? When the recording medium is carried onto the holding surface 1a, the recording medium sending-out plate 19 is in a position retreated from above the holding surface 11a, but the carrying-in rollers 13A and 13B move the recording medium onto the holding surface 1.
Figure 2(b)
As shown in the figure, it rotates in the direction of arrow E1 and moves to a position where it comes into contact with the rear end of the recording medium. Next, this recording medium feeding plate 19
As shown in FIG. 2(C), the recording body is further rotated in the direction of arrow E2, pushing the rear end of the recording body 5, and moving the recording body in the direction of arrow F2 to a predetermined position.

The recording medium holding means 11 is provided with a detector 20 such as a reflective photointerrupter or a limit switch at a portion where the leading end of the recording medium is located at the predetermined position. The leading edge of the recording medium pushed by the feed plate 19 to a predetermined position is detected and a detection signal is generated. This detection signal is transmitted to the drive member of the recording medium delivery plate 19, and the rotation of the recording medium delivery plate in the direction of arrow E2 is stopped. When the recording medium 5 is placed at a predetermined position on the holding surface 11a in this way, the recording medium feeding plate 19 retreats slightly in the direction of arrow E3, as shown in FIG. A two-dimensional scan is performed.

When the recording by the light beam is completed, the recording medium sending plate 19 rotates in the direction of the arrow E4 to push the leading end of the recording medium 5 and transfer the recording medium 5 to the recording medium holding means 11, as shown in FIG. 2(e). Move it to the other end. Near the other end of the recording medium holding means 11, there is a pair of carry-out rollers 21 serving as a means for carrying out the recording body.
A, 21B are provided, and a recording medium feeding plate 19 is provided.
The conveyance rollers 21A and 218 push and move the rear end of the recording medium until the leading end of the recording medium is gripped.

The recording medium 5 gripped by the carry-out rollers 21A and 21B in this manner is moved in the direction of arrow F3 by the rotation of the carry-out rollers, and is carried out to the outside of the recording apparatus. Note that the recording medium carried out from the apparatus is carried into, for example, an automatic developing machine or a receiving magazine, and the carrying out roller may also serve as an entrance roller of the automatic developing machine. When the recording medium is carried out of the apparatus in this way, the recording medium feeding plate 19
is rotated in the direction of the arrow Es, which is the opposite direction of the force direction of the arrow Ea, and returns to the position shown in FIG. 2(a) to allow the loading of a new recording medium. Note that the position where the detector 20 is provided is not limited to the above-mentioned position (for example, the detector 20 may be placed at a portion where the rear end of the recording body is located at a predetermined position in the recording body holding means where the recording body is held). may be provided to detect the rear end of the recording medium placed at a predetermined position.

Furthermore, in order to stop and position the recording medium 5 at a predetermined position, it is not necessary to use the detector 20 if very high positioning accuracy is not required. It is also possible to set an appropriate time and stop the recording medium delivery plate 1α at a position where the recording medium 5 is moved to a predetermined position. In this case, if a pulse motor is used as the motor 17, the braking operation can be easily performed.

As mentioned above, in the device of this embodiment, the carry-in roller,
By providing a carry-out roller, a detector for detecting the leading edge position of the recording body, and a recording body sending-out plate for moving the recording body as described above, the loading, unloading, and positioning of the recording body are carried out reliably. be able to. As shown in FIG. 1, when the recording medium is placed at a predetermined recording position, the recording medium is rotated in the direction of the arrow on the guide plate 22 provided at the side end of the recording medium holding means 11. By providing the width shifting plate 23 that presses the recording medium, the positioning of the recording medium in the main scanning direction can be performed with high precision.

The light beam scanning device of the present invention has been described above using a light beam recording device as an example. Information recording and reproducing system (Unexamined Japanese Patent Publication No. 55-1
No. 2429, No. 5t311395.

5G-11397, etc.), and can also be applied to various light beam reading devices such as the radiation image information reading device used in In this case, the reading means may be moved on the scanning sheet so as to face the scanning line in conjunction with the rotation of the sub-scanning mirror.

(Effects of the Invention) As explained in detail above, according to the light beam scanning device of the present invention, by performing sub-scanning with the scanning sheet fixed, the downtime of the device can be reduced, especially in the sub-scanning direction. I can do it. Furthermore, by performing sub-scanning using a sub-scanning reflective mirror and by making the scanning sheet arc-shaped, the optical system inside the device can be simplified, making it possible to further downsize the entire device. Become. Furthermore, the number of optical elements used can be reduced, the need for expensive optical elements can be eliminated, and the sub-scanning motor can be made inexpensive, so the manufacturing cost of the apparatus can be significantly reduced.

Further, by carrying in and out the scanning sheet by the carrying-in means and the carrying-out means, and by positioning the scanning sheet by the scanning sheet delivery plate, the carrying-in/unloading of the scanning sheet onto the arcuate holding surface and the carrying-out can be done reliably.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an overview of a light beam recording device according to an embodiment of the present invention, and FIGS. 2(a) to (e) are schematic diagrams illustrating loading, unloading, and positioning of a recording medium into the device. , 3 and 4 are perspective views showing the outline of a conventional light beam scanning device. 1... Beam light source 2... Light beam 3...
Rotating polygon &lI 4...imaging lens 5...
Recording body 10... fill scanning mirror 1
1... Recording body holding means 13Δ, 13B... Carrying roller 19... Recording body sending plate 20... Detector

Claims (1)

[Scope of Claims] 1) A light beam emitted from a beam light source is caused to scan a scanning sheet in a main scanning direction, and the light beam and the scanning sheet are moved relatively to each other in a sub-scanning direction substantially orthogonal to the main scanning direction. In a light beam scanning device that is moved in a scanning direction to two-dimensionally scan the light beam on the scanning sheet, a main unit that is provided on the optical path of the light beam emitted from the beam source and that deflects the light beam is provided. a scanning optical deflector; an imaging lens provided on the optical path of the light beam deflected by the main scanning optical deflector; A mirror that reflects a light beam, the line of intersection of a plane containing the optical path of the light beam that has passed through the imaging lens or a plane parallel to the plane and a plane perpendicular to the optical axis of the imaging lens approximately A sub-scanning mirror that rotates as a rotation axis, and a scanning sheet holding means that holds the scanning sheet in an arcuate shape having a central axis that substantially coincides with the rotation axis of the sub-scanning mirror, the scanning sheet a carry-in means provided near one end of the holding means for carrying the scanning sheet to a position in front of a predetermined position on the scanning sheet holding means; a sheet carrying-out means provided near the other end of the scanning sheet holding means; The sheet holding means is provided near the one end and pushes the rear end of the scanning sheet to move the carried scanning sheet toward the predetermined position, and also moves the scanning sheet at the predetermined position to the leading edge of the scanning sheet. A light beam scanning device comprising a scanning sheet feeding plate that can be moved to a position where the scanning sheet is gripped by the carrying out means.