JPH0458748B2 - - Google Patents

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, a light beam scanning device that deflects a light beam using an optical deflector and scans a scanning sheet relatively two-dimensionally has been used for various types of scanning, recording, and scanning. Widely used in reading devices and the like. 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 orthogonal to the . However, in conventional devices,
Various problems have arisen due to the means for performing the sub-scanning, such as the apparatus becoming larger and the optical system becoming complicated and expensive. Hereinafter, problems with the conventional light beam scanning device will be explained with reference to FIGS. 4 and 5. In the light beam scanning device shown in FIG. 4, a light beam 1 emitted from a beam light source 101
02 enters a rotating polygon mirror 103, which is an optical deflector, and is reflected and deflected as the rotating polygon mirror rotates in the direction of arrow A. 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 held between a rotating drum 106 rotating in the direction of arrow C and a pair of rollers 107A and 107B provided on the rotating drum, and is rotated in the main scanning direction as the rotating drum 106 rotates. Sub-scanning is performed by being conveyed in the substantially perpendicular direction of arrow D. Therefore, the light beam 102 two-dimensionally scans the scanning sheet 105 by repeatedly main-scanning it in the direction of the arrow B over the scanning sheet 105 that is conveyed (sub-scanned) in the direction of the arrow D in this way.

However, in the above-mentioned apparatus, sub-scanning is performed by moving the scanning sheet, but in order to suppress variations in load on the motor 108 during sub-scanning as much as possible to prevent uneven sub-scanning from occurring. , a support stand 10 supporting the scanning sheet 105 before and after the scanning position by the light beam as shown in the figure.
9 and 110, respectively, to provide a space in which one scanning sheet can be placed. For this reason, the above-mentioned apparatus requires a space having a length of two or more scanning sheets in the sub-scanning direction, resulting in an increase in the size of the entire apparatus. Further, the rotating drum 106 that conveys the scanning sheet has a width larger than the sub-width of the scanning sheet in order to stably convey the scanning sheet.
Since a motor 108 for rotating the drum is further provided in the width direction of the rotating drum, the above-mentioned device becomes large in the main scanning direction as well.

Furthermore, in order to perform highly accurate scanning on the scanning sheet while conveying the scanning sheet, it is necessary to strictly control the motor so that the scanning sheet can be conveyed with high precision in the correct direction at a constant speed. However, since a highly accurate motor that can be controlled as described above is expensive, 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 rollers 107A, 10
7B is essential, but due to 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 respond to your request for a blackout.

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 has been proposed that performs sub-scanning without moving the scanning sheet.Hereinafter, a light beam scanning device with a fixed scanning sheet will be described with reference to FIG. Note that the same parts as those in the apparatus shown in FIG. 4 are given the same numbers and their explanations will be omitted.

The apparatus shown in FIG.
A scanning sheet 111 rotates at a low speed in the direction of arrow C and is fixed at a predetermined position along with a rotating polygon mirror 103 that performs main scanning in the direction of arrow B above.
A sub-scanning galvanometer mirror 112 is provided to reflect and deflect the light beam so that the main scanning line moves in the direction of arrow D. 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 sub-scanning galvanometer mirror 112 finishes scanning one scanning sheet, it returns to its original position and prepares for scanning the next scanning sheet. Furthermore, an fθ lens 113 that is an imaging lens is provided between the sub-scanning galvanometer mirror 112 and the scanning sheet 111, and this fθ lens is reflected at a constant angular velocity by the rotating polygon mirror 103 and the sub-scanning galvanometer mirror 112. The deflected light beam is caused to scan linearly at a constant speed on a flat scanning sheet surface.

By the way, in the above device, the rotating polygon mirror 1
In order to make the light beam that takes the optical path deflected by 03 and spread out enter the reflecting surface of the relatively small sub-scanning galvanometer mirror, the optical path of the light beam is once focused, and after passing through this focusing position, it is redirected to the rotating polygon. A relay lens 114 is provided that adjusts the optical path of the light beam so that it reproduces the deflection caused by the mirror and spreads. 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 completely incident on the sub-scanning galvanometer mirror and deflected by the relay lens 114.
After being reflected and deflected by the sub-scanning galvanometer mirror, the light beam widens its optical path again at an angle corresponding to the deflection of the rotating polygon mirror 103, so that a main scanning line of the required length can be obtained on the scanning sheet 111. .

However, in the apparatus shown in FIG. 5, in addition to the imaging lens 113, the relay lens 11 is
4, the optical system becomes complicated and the device cannot be sufficiently miniaturized. There is also the problem that the provision of the relay lens increases the number of optical elements, which increases 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) A light beam scanning device of the present invention includes: a main scanning optical deflector that is provided on an optical path of a light beam emitted from a beam light source and deflects the light beam; an imaging lens provided on the optical path of the deflected light beam; a mirror provided on the optical path of the light beam passing through the imaging lens to reflect the light beam with a reflective surface; a plane containing the optical path of the light beam passing through or a plane parallel to the plane;
a sub-scanning mirror that rotates about an intersection with a plane perpendicular to the optical axis of the imaging lens, and an arcuate surface having a central axis that substantially coincides with the drive axis of the sub-scanning mirror; The first feature is that it includes a scanning sheet holding means for holding a scanning sheet.

That is, in the light beam recording device of the present invention, since the recording medium is fixed by the recording medium holding means, it is not necessary to use a large device in the sub-scanning direction, as in the case where the recording medium is conveyed to perform sub-scanning. There is no need to do this, and the entire device can be made more compact. In addition, the light beam reflected by the main scanning optical deflector passes through the imaging lens and is directly reflected by the sub-scanning mirror for sub-scanning, so there is no need to provide a relay lens, etc., and the optical system is simple.
It will be cheap. In addition, the sub-scanning mirror is
Since a light beam whose optical path is widened by being deflected by the main scanning optical deflector is incident, it is preferable to use a long mirror extending in the main scanning direction in terms of designing the optical system.

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 device of the present invention is provided near one end of the scanning sheet holding means,
A carry-in means for carrying the scanning sheet up to 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, and a lower part of the scanning sheet holding surface of the scanning sheet holding means. extends in the main scanning direction, and is movably provided so that the upper end can take a first position on the holding surface and a second position where the upper end is retracted from the holding surface. The scanning sheet that has been rotated and carried in is moved toward the predetermined position, and the scanning sheet is reversed at the first position so that the rear end of the scanning sheet is gripped by the conveying means. The second aspect of the present invention is to have a scanning sheet feed roller that can be moved to a position where
This is the characteristic of

(Embodiments) Hereinafter, embodiments 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, and then is modulated. Arrow A
The light enters a rotating polygon mirror 3, which is a main scanning optical deflector, and is deflected. 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. Furthermore, in addition to the above-mentioned rotating polygon mirror, as a main scanning optical deflector,
Other types of optical deflectors such as galvanometer mirrors, acousto-optic optical deflectors (AOD) may also be used.

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.
After passing through, the light is incident on the reflective surface 10a of a long sub-scanning reflective mirror 10 extending in the main scanning direction, which is driven by the motor 9 and rotated at a low speed in the direction of arrow C, and is reflected. In addition, this sub-scanning mirror 1
On the optical path of the light beam reflected by the sub-scanning mirror below 0, a sheet-like recording medium 5 such as a photographic film or photographic paper is placed on an arc-shaped holding surface 11a.
The recording medium is held in an arcuate shape by a recording medium holding means 11 having a shape. This holding means 11 is formed by, for example, bending a plate-like object or integrally molding it using synthetic resin or the like. Further, the central axis of the arcuate surface formed by the recording body 5 is substantially coincident 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 deflected by the rotating polygon mirror 3 main scans 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 the sub-scanning mirror may be located at a position slightly shifted from the above-mentioned reflection position within a range that does not pose a problem in terms of scanning accuracy of the light beam, such as the center position in the thickness direction of the mirror.

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 rotating 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 arrow D, 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. rotate in the opposite direction,
Alternatively, it is further rotated in the rotational direction and returned to the initial position, such as by making one rotation, in preparation for recording on the next recording medium. Note that in this embodiment, the first
As shown in the figure, a photodetector 12 is mounted on the recording medium holding means 11, and the photodetector 12 detects a light beam to determine the image recording scanning start position. That is, the sub-scanning mirror 10
is rotated from the initial position in the direction of arrow C, and it is detected that the light beam has reached the end of the recording medium 5. At this point, the light modulator 6 is operated based on the image signal to modulate the light beam 2. , image recording on the recording body 5 is started.

As described above, in the apparatus of the present invention, sub-scanning is performed by fixing the recording medium and moving the light beam by rotating the sub-scanning mirror 10. Therefore, when moving the recording medium, In comparison, the size of the device in the sub-scanning direction can be reduced to about half. Further, even when the sub-scanning mirror 10 is made long and extends in the main scanning direction as in the above embodiment, the length of the sub-scanning mirror 10 in the main scanning direction is such that the incident light beam is It is sufficient that the length is sufficient to allow the recording medium to hold the recording medium, and it is sufficient that the length is shorter than the length of the main scanning line on the recording medium, so even if the sub-scanning mirror 10 and the motor 9 are combined, It is sufficiently possible to make the length shorter than the length in the main scanning direction, and the apparatus of the present invention is also compact in the main scanning direction. In addition,
The sub-scanning mirror 10 does not necessarily have to be long as long as it can be placed sufficiently close to the main-scanning optical deflector, and its shape also allows it to rotate about the above-mentioned rotation axis. , 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. Further, since the recording medium 5 held by the sheet holding means 11 can be irradiated with a light beam from the front end to the rear end in the sub-scanning direction to perform recording on the entire surface of the recording medium, both ends of the recording medium can be blacked out ( It is also possible to make it black. Note that depending on the type of recording medium, if the recording medium 5 does not fit well on the holding surface 11a of the recording medium holding means 11 and it is difficult to maintain it in an arcuate shape, a suction means may be provided in the recording medium holding means 11. Holding surface 1 for recording
It may be adsorbed onto 1a.

In addition, in the apparatus of the present invention, the light beam 2 deflected by the main scanning optical deflector 3 as described above is used.
Since the sub-scanning mirror 10 that allows all of the light to enter is provided, there is no need to provide a relay lens or the like to adjust the optical path of the light beam 2, which simplifies the optical system, making the device even more compact, and making it easier to manufacture. 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 the light beam, the recording medium 5
must be reliably carried in along the arc-shaped holding surface, accurately positioned at a predetermined position on the holding surface, and must be reliably carried out along the arc-shaped holding surface after scanning is completed. Therefore, the above-mentioned apparatus is provided with a conveyance means and a positioning means for carrying in and out the recording medium. Each of the above means will be explained below with reference to FIGS. 1, 2, and 3.

Near one end of the recording medium holding means 11, a pair of conveying rollers 13A and 13B, which serve as recording medium conveying means, are provided that are rotatable in forward and reverse directions. These conveyance rollers 13A, 13B, when carrying in the recording bodies, are sucked one by one by the suction means 16 from the magazine 14 in which a plurality of recording bodies 5 are stored in the forward direction as shown in FIG. 3a. After that, the recording medium 5 that falls while being guided by the guide plate 15 is grasped, rotated in the direction of arrow _E1 , and carried in along the holding surface 11a.

The conveyance rollers 13A, 13B are
By rotating in the _E1 direction, the recording medium 5 is sent in the arrow _F1 direction, and the recording medium 5 is placed on the holding surface 11 as shown in FIG. 3b.
The recording medium 5 is conveyed to the front of the predetermined position on a where it is to be held.

The recording medium 5 that has been carried to the front of the predetermined position in this way is moved to the second position, which is a plan view of the recording medium holding means 11.
As shown in the figure, the holding surface 1 of the recording medium holding means 11
1a extending in the main scanning direction, located in an opening 18 provided in the holding surface 11a and exposed to the holding surface, and having an upper end on the holding surface; The recording body is moved to a predetermined position by a recording body feeding roller 17, which is movably provided so that it can take a second position where it retreats. That is, as shown in FIG.
The upper end is at the second position retreated from the holding surface 11a, but when the recording medium is carried by the conveyance rollers 13A and 13B to a position just before the predetermined position on the holding surface 11a, it moves upward as shown in FIG. 3b. It moves to the first position and comes into contact with the lower surface of the recording medium.
At this first position, the recording medium feed roller 1
7 rotates normally in the direction of arrow _G1 and moves the recording medium 5 to a predetermined position in the direction of arrow _F2 , as shown in FIG. 3c.

Note that the roller 17 is not configured to be in contact with the entire width of the recording medium 5, but may be in contact only with both ends or the center portion.

The recording medium holding means 11 includes a reflective photointerrupter, a limit switch, etc., which are exposed in the holding surface 11a through an opening 19, as shown in FIG. A detector 20 is provided,
This detector 20 detects the leading edge of the recording medium that has reached a predetermined position by the recording medium feed roller 17 and generates a detection signal. This detection signal is transmitted to a driving member (not shown) of the recording medium feed roller 17, and the rotation of the recording medium feeding roller is stopped. When the recording medium 5 is placed at a predetermined position on the holding surface 11a, the recording medium feeding roller 17 is moved as shown in FIG.
is lowered and retreated to the second position, and in this state two-dimensional scanning by the light beam is performed.

When the recording by the light beam is completed, as shown in FIG. 3e, the recording medium feed roller 17 moves upward again to the first position, reverses in the direction of arrow _G2 , and starts recording the recording medium 5. The body holding means 11 is moved to the one end side again. This recording medium feed roller 1
7 starts reverse rotation, the conveyance rollers 13A,
13B also rotates in the direction of arrow _E2 , which is the opposite direction to the normal direction, and the recording body feed roller 17 moves the recording body until the leading end of the recording body is gripped by the conveying rollers 13A and 13B. The recording medium 5 gripped by the conveyance rollers 13A and 13B in this way is
It is moved in the direction of the arrow _F3 by conveyance rollers 13A and 13B rotating in _{the two} directions E, and is carried out to the outside of the recording apparatus. Before carrying out the recording medium, the guide plate 15 is moved from the position indicated by the solid line in FIG. 3a to the position indicated by the solid line in FIG. 3e (FIG. 3a).
If you move it to the position shown by the dashed line in
The recording medium can be carried out in a direction different from the direction in which the magazine 14 is provided, making it easier to carry it into an automatic developing machine, a receiving magazine, or the like. Note that a cassette containing only one recording medium is provided in place of the magazine 14, and after the recording medium is carried into the apparatus and recording is performed on this recording medium, the recording medium is stored in the empty cassette. When returning the finished recording medium, there is no need to move the guide plate 15. When the recording medium is carried out of the apparatus in this manner, the recording medium feed roller 17 descends and returns to the second position, allowing the introduction 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 installed at a portion of the recording body holding means where the rear end of the recording body is located at a predetermined position where the recording body is held. Alternatively, the rear end of the recording medium placed at a predetermined position may be detected.

Further, for stopping and positioning the recording medium 5 at a predetermined position, it is not necessarily necessary to use the detector 20 when positioning accuracy is not required to be very high. by appropriately setting the recording body feed roller 1.
7 may be stopped 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, control can be easily performed. Alternatively, a stop plate may be provided at the other end of the arcuate holding base to forcibly stop the recording medium 5 at a predetermined position.

As described above, the apparatus of this embodiment is provided with a conveyance roller, a detector for detecting the position of the leading edge of the recording medium, and a recording medium feed roller for moving the recording medium as described above, so that recording is possible. The body can be carried in, carried out, and positioned reliably. As shown in FIG. 1, when the recording medium is placed at a predetermined recording position, the guide plate 2 provided at the side end of the recording medium holding means 11
2, if a width shifting plate 23 is provided which rotates in the direction of the arrow and presses the recording medium, the positioning of the recording medium in the main scanning direction can also 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 (JP-A No. 55-12429, No. 56-11395)
It can also be applied to various light beam reading devices such as the radiation image information reading device used in Japanese Patent No. 56-11397, etc.), and the above-mentioned effects can be achieved in the same way in light beam reading devices. 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 described above in detail, according to the light beam scanning device of the present invention, by performing sub-scanning with the scanning sheet fixed, the entire device can be downsized, especially in the sub-scanning direction. can. Furthermore, by performing sub-scanning with a sub-scanning mirror and making the scanning sheet arc-shaped, the optical system inside the device can be simplified, making it possible to further downsize the entire device. . 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.

Furthermore, the scanning sheet is carried in and out by a conveying means such as a conveying roller, and the scanning sheet is positioned by a scanning sheet feeding roller, so that the scanning sheet is carried in, positioned, and Transport can be carried out reliably.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an overview of a light beam recording device according to an embodiment of the present invention, FIG. 2 is a plan view showing a recording medium holding means of the device, and FIG. 3 a to e are shown in FIG. 1. A schematic diagram illustrating loading, unloading, and positioning of a recording medium into the apparatus, and FIGS. 4 and 5 are perspective views showing an outline of a conventional light beam scanning apparatus. 1... Beam light source, 2... Light beam, 3... Rotating polygon mirror, 4... Imaging lens, 5... Recording body, 1
0... Sub-scanning mirror, 11... Recording body holding means, 13A, 13B... Conveyance roller, 17... Recording body feeding roller, 20... Detector.

Claims (1)

[Scope of Claims] 1. A light beam emitted from a beam light source is scanned on a scanning sheet in a main scanning direction, and the light beam and the scanning sheet are relatively scanned in a sub-scanning direction substantially orthogonal to the main scanning direction. A light beam scanning device that scans the light beam two-dimensionally on the scanning sheet by moving the light beam in a direction, the main scanning device being provided on the optical path of the light beam emitted from the beam source and deflecting the light beam. an optical deflector for main scanning; an imaging lens provided on the optical path of the light beam deflected by the main scanning optical deflector; a plane that is a mirror that reflects the beam and includes the optical path of the light beam that has passed through the imaging lens, or a plane that is parallel to the plane;
a sub-scanning mirror that rotates about an intersection with a plane perpendicular to the optical axis of the imaging lens, and an arcuate surface having a central axis that substantially coincides with the rotation axis of the sub-scanning mirror; a scanning sheet holding means for holding the scanning sheet, provided near one end of the scanning sheet holding means,
a carry-out means capable of being driven in a forward direction to carry the scanning sheet to a position in front of a predetermined position on the scanning sheet holding means and being driven in a reverse direction to carry out the scanning sheet; The sheet holding means extends in the main scanning direction below the scanning sheet holding surface, and is movable so that its upper end can take a first position on the holding surface and a second position where it retreats from the holding surface. The scanning sheet is rotated forward in the first position and carried in, and the scanning sheet is moved toward the predetermined position. A light beam scanning device comprising a scanning sheet feeding roller that can be moved to a position where the rear end thereof is gripped by the conveying means.