JPH10149427A - Cortical scanning device, optical information reader and optical information recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly precisely read information to be read and to miniaturize and simplify the device itself. SOLUTION: A telecentric lens 10 sets scanning width in the main scanning direction on an original 6 constant by making respective main light beams parallel on the light beams for information reading R, which ate deflected and scanned in the main scanning direction by a polygon mirror 2. Furthermore, a focus position is changed in accordance with the movement of a moving mirror 9 by a pair of Fresnel lenses (a Fresnel lens face 6A (positive lens) and a Fresnel lens face 6B (negative lens)) formed in an original stand 6G, and the focus position is always set on the original 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information apparatus including an optical scanning device for irradiating a recording medium such as a document on which information to be read is recorded with a light beam and reading the information by reflected light. A reading device and an optical information recording device, wherein the recording medium is fixed, and the optical information reading device and the optical information recording device include an optical scanning device that reads information by scanning the recording medium with a light beam. Belong.

[0002]

2. Description of the Related Art Conventionally, in an optical information reading apparatus for reading information from a fixed recording medium on which information to be read is recorded, a light beam such as a laser beam from a light source is recorded by a polygon mirror (rotating polygon mirror) or the like. Deflected scanning is performed in the main scanning direction on the medium (for example, in the case of a normal horizontal writing document, the horizontal writing direction), and a so-called fθ lens (also referred to as an equidistant projection lens), the image height h is determined by the incident tilt angle θ and the focal length and a lens that is proportional to the product of f (that is, h = f × θ) and has a function of converting uniform angular velocity deflection into linear scanning at constant velocity. By moving the entire moving member including the light source, the polygon mirror and the fθ lens in the sub-scanning direction perpendicular to the main scanning direction, the information is read by scanning the entire recording medium.

When recording read information,
The read information is temporarily stored, and then the recording light beam is modulated by the stored read information, and the modulated light beam is irradiated on the photoconductor to correspond to the information on the photoconductor. An electrostatic latent image is formed, and a toner charged in a polarity opposite to that of the photoreceptor in advance is brought into contact with the photoreceptor on which the electrostatic latent image is formed, and the photoreceptor remains in a portion irradiated with the recording light beam. The information is recorded (ie, copied) by transferring the toner onto a predetermined recording sheet.

[0004]

However, in the above-mentioned conventional optical information reading apparatus, since the rotating polygon mirror itself is moved in the sub-scanning direction, the vibration in the rotation of the polygon mirror propagates to the whole moving member, As a result, there is a problem that the light beam itself irradiated on the recording medium vibrates and an image corresponding to the read information is disturbed (so-called “brell”).

Further, when the entire moving member is moved, the acceleration time required to reach the scanning speed for the sub-scanning and the deceleration time required to stop the sub-scanning become longer, so that the information read at the peripheral portion of the recording medium is reduced. In addition to the distortion, the distance required for accelerating and decelerating the moving member is increased, resulting in a problem that the optical information reading apparatus is enlarged.

Accordingly, the present invention has been made in view of the above-mentioned problems, and its object is to enable information to be read to be read with high precision and to reduce the size of the apparatus itself.
An object is to provide an optical scanning device, an optical information reading device, and an optical information recording device that can be simplified.

[0007]

According to a first aspect of the present invention, there is provided a light emitting device, such as a semiconductor laser for emitting a light beam, which scans the emitted light beam. Deflection scanning means such as a polygon mirror for deflecting and scanning in the main scanning direction on a recording medium on which information to be recorded is recorded, and condensing the deflection-scanned light beam in the main scanning direction; Scanning width stabilizing means for setting the scanning width of the light beam in the main scanning direction to a predetermined constant width corresponding to the recording medium; and sub-scanning the deflection-scanned light beam perpendicular to the main scanning direction. Focusing means for focusing in the direction, and moving mirror means such as a moving mirror for reflecting the focused light beam and moving in the sub-scanning direction to irradiate the recording medium with the focused light beam And the transfer A focus position changing unit that changes a distance from the deflection scanning unit to a focal position of the light beam in accordance with the movement of the mirror unit in the sub-scanning direction, and sets the focal position on the recording medium. .

According to the operation of the first aspect of the present invention, the emitting means emits a light beam. The deflection scanning means deflects and scans the emitted light beam in the main scanning direction.
Thereafter, the scanning width fixing means condenses the light beam deflected and scanned in the main scanning direction, and sets the scanning width of the light beam on the recording medium in the main scanning direction to a predetermined constant width.

On the other hand, the condensing means condenses the light beam deflected and scanned in the sub-scanning direction. At this time, the moving mirror means reflects the collected light beam and moves in the sub-scanning direction while irradiating the recording medium with the collected light beam.

The focal position changing means changes the distance from the deflection scanning means to the focal position of the light beam in accordance with the movement of the moving mirror means in the sub-scanning direction, and sets the focal position on the recording medium.

Therefore, since the scanning in the sub-scanning direction is performed by moving the moving mirror means, there is no need to move the deflecting scanning means itself, and the deflection is performed as compared with the case where the deflecting scanning means itself is moved in the sub-scanning direction. It is possible to eliminate the influence of the vibration or the like on the scanning means on the scanning, and to scan information with high accuracy.

Further, since the scanning width in the main scanning direction on the recording medium is made constant by the scanning width fixing means, and the focal position of the light beam is set on the recording medium by the focal position changing means, the moving mirror means moves. Even in this case, it is possible to accurately scan the recording medium at a constant width.

According to a second aspect of the present invention, there is provided an optical scanning apparatus according to the first aspect, wherein the focus position changing means is provided between the moving mirror means and the recording medium. Placed on the optical path of the light beam,
It is configured to be a Fresnel pair lens including a positive lens and a negative lens, which are Fresnel lenses having refractive power only in the main scanning direction.

According to the second aspect of the present invention, in addition to the first aspect of the present invention, the focal position changing means is provided on the optical path of the light beam between the moving mirror means and the recording medium. And a Fresnel pair lens composed of a positive lens and a negative lens, which are Fresnel lenses having refractive power only in the main scanning direction, so that the configuration of the focus position changing means can be simplified.

According to a third aspect of the present invention, there is provided an optical scanning apparatus according to the first or second aspect, wherein the scanning width stabilizing means is configured to control each of the light beams after deflection scanning. It is configured to be a telecentric lens that makes the principal rays of the beam parallel to each other and makes the scanning width of the light beam on the recording medium the constant width.

According to the operation of the third aspect of the invention, in addition to the operation of the first or second aspect of the present invention, since the scanning width stabilizing means is a telecentric lens, the configuration of the optical scanning device is simplified. Can be

According to a fourth aspect of the present invention, there is provided an optical scanning apparatus according to the second aspect, wherein the Fresnel pair lens is a mounting table on which the recording medium is mounted. Be composed.

According to the operation of the fourth aspect of the present invention, in addition to the operation of the second aspect of the invention, the Fresnel pair lens also serves as a mounting table on which the recording medium is mounted, so that the optical scanning device is used. The entire configuration can be simplified.

According to a fifth aspect of the present invention, there is provided an optical scanning apparatus according to any one of the first to fourth aspects, wherein the light converging means comprises: A first cylindrical lens that is arranged on the optical path of the light beam between the scanning width stabilizing unit and converts the light beam deflected and scanned in the sub-scanning direction into a parallel light beam; While being arranged and moving in the sub-scanning direction together with the moving mirror means,
A second cylindrical lens for condensing the light beam converted into the parallel light beam on the recording medium.

According to the operation of the invention described in claim 5, in addition to the operation of the invention described in any one of claims 1 to 4, the first cylindrical lens that constitutes the light condensing means includes:
It is arranged on the optical path of the light beam between the deflection scanning means and the scanning width stabilizing means, and converts the light beam deflected and scanned in the sub-scanning direction into a parallel light beam.

The second cylindrical lens, which is arranged in the moving mirror means and moves in the sub-scanning direction and forms the light condensing means, condenses the light beam converted into a parallel light beam on a recording medium.

Therefore, the configuration of the light condensing means can be simplified, and the light beam can be condensed on the recording medium in the sub-scanning direction even if the moving mirror means moves in the sub-scanning direction. According to a sixth aspect of the present invention, there is provided an optical scanning device according to any one of the first to fifth aspects, wherein the optical scanning device moves integrally with the moving mirror means, and A light receiving unit such as a light receiving unit that receives reflected light of the light beam applied to the recording medium by a mirror unit and outputs a light receiving signal; and outputs a read signal corresponding to the information based on the light receiving signal. And reading means such as a CPU.

According to the function of the invention described in claim 6, in addition to the function of the invention described in any one of claims 1 to 5, the light receiving means moves integrally with the movable mirror means and And receiving the reflected light of the light beam applied to the recording medium by the moving mirror means and outputting a light receiving signal.

The reading means outputs a reading signal corresponding to the information based on the light receiving signal. Therefore, the information on the recording medium is scanned with high accuracy, and a read signal corresponding to the information is output, so that the information can be read with high accuracy.

According to a seventh aspect of the present invention, in the optical scanning device according to the sixth aspect, the light receiving means includes a plurality of light receiving elements for receiving the reflected light. The recording medium is arranged in a plane parallel to a recording surface of the information and in a direction parallel to the main scanning direction.

According to the function of the invention described in claim 7, in addition to the function of the invention described in claim 6, the light receiving means includes a plurality of light receiving elements for receiving the reflected light, the information recording surface of the recording medium. And arranged in a direction parallel to the main scanning direction, the level of the light receiving signal can be increased, and the information on the recording medium can be read with high accuracy.

In order to solve the above-mentioned problem, the invention according to claim 8 provides an optical information reading device according to claim 6 or 7, and a storage means such as a RAM for storing the read signal,
Based on the stored read signal, a recording light beam emitting unit such as a semiconductor laser that emits a recording light beam corresponding to the information to the deflection scanning unit, and a recording light beam that has been deflected and scanned. Guiding means such as a dichroic mirror for guiding recording light beam focusing means such as an imaging lens for focusing the recording light beam on information holding means such as a photoreceptor for holding the information. Prepare.

According to the operation of the invention described in claim 8, in addition to the operation of the invention described in claim 6 or 7, the storage means stores a read signal. Then, the recording light beam emitting means emits a recording light beam corresponding to the information to the deflection scanning means based on the stored read signal.

Thereafter, the guiding means guides the deflection-scanned recording light beam to the recording light beam focusing means for focusing the recording light beam on the information holding means. Therefore, information read by scanning with high accuracy can be held, and thus the read information can be recorded accurately and reliably.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment in which the present invention is applied to a copying machine in which an optical system for reading information and an optical system for recording information are partially shared will be described with reference to FIGS. 3 will be described. (I) Overall Configuration and Operation First, the overall configuration of the copying machine according to the embodiment will be described with reference to FIG.

As shown in FIG. 1, the information reading system of the copying machine P according to the present embodiment is driven by a drive signal Sv from a control unit 30 to be described later, and emits a light beam R for reading information. A dichroic mirror D that transmits a light beam R from the semiconductor laser 1, a polygon mirror 2 as deflection scanning means for deflecting and scanning the light beam R in a main scanning direction indicated by an arrow in FIG. A first cylindrical lens 5 as a condensing means for converting the light beam R deflected and scanned by the polygon mirror 2 into a parallel light beam in the sub-scanning direction perpendicular to the main scanning direction, and via the first cylindrical lens 5 Light beam R
A dichroic mirror 4 for irradiating the original 6 as a recording medium, a telecentric lens 10 as scanning width stabilizing means for making the principal rays of the respective light beams R transmitted through the dichroic mirror 4 parallel to each other, A second cylindrical lens 21 as a light condensing means for condensing the light beam R, which is a parallel light beam in the scanning direction, on the original 6, and the original 6 by the second cylindrical lens 21.
A light receiving unit 7 serving as a light receiving means for receiving the reflected light of the light beam R condensed from the original 6 and generating a light receiving signal Sd corresponding to the original 6, and arranged at a position outside the scanning range of the original 6 A photodiode detector 8 that outputs a sensor signal Sp when the light beam R is incident upon each one of the deflection scans in the main scanning direction, and a control unit 30 that controls the entire apparatus. It is configured. In this configuration,
The light receiving unit 7 is disposed in a movable mirror 9 described later,
It is composed of three photodiodes 7a, 7b and 7c arranged in a direction parallel to the main scanning direction in a plane parallel to the surface of the original 6, and moving in the sub-scanning direction perpendicular to the main scanning direction. The reflected light of the light beam R is received to output a light receiving signal Sd.

On the other hand, the information recording system in the present embodiment
The semiconductor laser 1 ′ is driven by a drive signal Svr from the control unit 30 and emits a recording light beam G for information recording, and a recording light beam G from the semiconductor laser 1 ′. A dichroic mirror D, a polygon mirror 2, a first cylindrical lens 5, a dichroic mirror 4 as a guiding means for reflecting the recording light beam G in the direction of the photoconductor 20, and a recording reflected by the dichroic mirror 4 An imaging lens 3 as a recording light beam condensing means constituted by the fθ lens for condensing the recording light beam G on the photoreceptor 20, and by irradiating the collected recording light beam G And a photoreceptor 20 as information holding means for forming an electrostatic latent image. Here, the photoconductor 20 is controlled to rotate by a predetermined amount each time the recording light beam G scans one line in the main scanning direction of the photoconductor (corresponding to the main scanning direction of the document 6). It is controlled by the unit 30.

The recording light beam G reflected by the dichroic mirror 4 sets the optical path length of the recording light beam G such that the focal point of the recording light beam G is located on the photosensitive member 20. After being reflected by the reflecting mirrors 13 and 14 shown in FIG.

The oscillation wavelengths of the semiconductor laser 1 'and the semiconductor laser 1 are such that the light beam R emitted from the semiconductor laser 1 passes through the dichroic mirrors 4 and D and the recording light emitted from the semiconductor laser 1'. Beam G
Are set to be reflected by the dichroic mirrors 4 and D, respectively.

The photosensitive member is a recording light beam G.
In addition to the photoreceptor 20 that forms an electrostatic latent image by the irradiation of the photoreceptor, a photoreceptor carrying microcapsules that are cured by the irradiation of the recording light beam G can be used. The photoreceptor carrying the microcapsules has a recording light beam G
In addition to curing the microcapsules corresponding to the information to be recorded by the irradiation, the uncured microcapsules are broken and developed by applying pressure, and the developed images are transferred to recording paper.

Next, an example of the optical scanning section S in which the semiconductor lasers 1 and 1 ', the dichroic mirror D, the polygon mirror 2, the imaging lens 3, and the dichroic mirror 4 shown in FIG. 1 are actually arranged will be described with reference to FIG. explain.

As shown in FIG. 2, a semiconductor laser unit 11 including the semiconductor laser 1 and a semiconductor laser unit 12 including the semiconductor laser 1 ′ are provided in the housing BD forming the optical scanning unit S with the semiconductor laser 1. The semiconductor laser 1 ′ is arranged so that the optical axis is substantially perpendicular. The light beam R or the recording light beam G is applied to the dichroic mirror D via a collimator lens C for making the light flux substantially parallel and a stop M for making the spot diameter on the document 6 a predetermined size. Incident. After the light beam R is transmitted by the dichroic mirror D and the recording light beam G is reflected, the optical paths of the respective light beams are made the same, and then, in one direction (in the case of the optical scanning unit S, Then, the light beam enters the regular hexagonal polygon mirror 2 disposed at the focal position of the cylindrical lens E via the cylindrical lens E that converges the light beam only in the sub-scanning direction (the direction perpendicular to the paper surface in FIG. 2). When the polygon mirror 2 rotates at a constant speed, the light beam R or the recording light beam G incident on the polygon mirror 2 is scanned at a constant speed in a direction (main scanning direction) parallel to the plane of FIG. The light is directed to the imaging lens 3 and the dichroic mirror 4. At this time, the light beam R is reflected by the reflection mirror MR provided outside the light receiving surface of the dichroic mirror 4 before each scan.
Through the photodiode detector 8. The photodiode detector 8 determines the scanning position of the light beam R on the original 6 based on the sensor signal Sp output from the photodiode detector 8 based on the scanning start timing (that is, the light beam R is transmitted to the photodiode detector 8). Is detected as an elapsed time from the timing at which light is incident).

Next, a specific mechanism for scanning the original 6 in the information reading system and its operation will be described with reference to FIG. FIG. 3A is a side sectional view of the copying machine P of the present embodiment, and FIG. 3B is an enlarged side view of a document table 6G which is a feature of the present invention. () Is a cross-sectional view taken along line AA ′ in FIG. 3B of the document table 6G.

In FIG. 3, the same members as those in FIG. 1 or FIG. 2 are denoted by the same reference numerals. In FIG. 3A, when the light beam R is applied to the original 6 placed on the original table 6G as a focal position changing unit for placing the original 6 to read information on the original 6, , The light beam R
Is emitted from the dichroic mirror 4 (that is, while being scanned in the main scanning direction), enters the first cylindrical lens 5, and is converted into a parallel light beam in the sub-scanning direction by the first cylindrical lens 5, and becomes a dichroic mirror. 4, the reflecting mirror 9A in the moving mirror 9 as a moving mirror means including a reflecting mirror 9A, a light receiving unit 7, and a detection lens 9B for condensing the reflected light of the light beam R from the document 6 on the light receiving unit 7. And its optical axis direction is changed to a direction substantially perpendicular to the direction of the original 6 surface. Then, the light beam R in the sub-scanning direction is emitted by the second cylindrical lens 21 arranged in the moving mirror 9.
Is set on the document 6 and the document 6 is irradiated. The light beam R reflected by the document 6 (intensity-modulated by the information on the document 6) is condensed on the light receiving section 7 by the detection lens 9B and received by the light receiving section 7, and the light receiving signal is received. Sd is generated.

At this time, in parallel with the above operation, the moving mirror 9 is moved at a constant speed in the sub-scanning direction of the original 6 by a driving mechanism (not shown), so that the irradiation position of the light beam R is moved at a constant speed in the sub-scanning direction. And the scanning of the surface of the original 6 is executed in combination with the deflection in the main scanning direction by the polygon mirror 2, the corresponding light receiving signal Sd is output to the CPU 31 via the detection circuit 32, and the reading signal Sr is generated. It is temporarily stored in a RAM 34 described later.

Here, when the moving mirror 9 moves in the sub-scanning direction, the optical path length of the light beam R from the polygon mirror 2 (or the imaging lens 3) to the original 6 is shifted rightward in FIG. Gradually become shorter in response to the movement of Thereby, the polygon mirror 2 at the position where the light beam R should be focused is
The distance from (the distance to the focal position) changes,
The scanning width of the light beam R radially deflected and scanned by the polygon mirror 2 also changes (more specifically, regarding the change in the scanning width, the scanning angle of the polygon mirror 2 per fixed time is constant and the deflection angle is constant). Since each of the scanned light beams R travels straight, the scanning width increases when the optical path is long and the scanning width decreases when the optical path is short, depending on the length of the optical path of the light beam R.)

Therefore, in the present embodiment, the scanning width of the light beam R on the document 6 is made constant by the telecentric lens 10 regardless of the movement of the movable mirror 9, and the light beam R passes through the document table 6G. Moving mirror 9
The light beam R is corrected so that the focal position of the light beam R is always on the document 6 irrespective of the movement of.

Here, the document table 6G through which the light beam B passes will be described in more detail. In the document table 6G, the Fresnel lens surface 6A is formed in a groove shape parallel to the sub-scanning direction.
(It has a groove shape as a Fresnel positive lens. FIG.
See (c). ) And a Fresnel lens surface 6B (having a groove shape as a Fresnel negative lens; see FIG. 3C) are formed as Fresnel pair lenses. Here, the Fresnel pair lens is a lens having a configuration in which Fresnel cut surfaces of two Fresnel lenses having a convergence effect only in one direction face each other. The shapes of the Fresnel lens surfaces 6A and 6B are shown in FIG.
As shown in (b), the Fresnel lens surface 6B is formed on a parabola in cross section, and the Fresnel lens surface 6A is formed on a straight line in cross section. With this shape, the Fresnel lens surface 6A and the Fresnel lens surface 6B have a refractive power only in the main scanning direction.

The cross-sectional shapes of the Fresnel lens surfaces 6A and 6B are set so that the focal position of the light beam R incident on the document table 6G is always on the document 6 with the movement of the moving mirror 9. ing. That is, FIG.
In (a) and (b), when the light beam R is incident on the left end of the document table 6G, the optical path length of the light beam R from the polygon mirror 2 to the document 6 is the longest. When the focal position of the light beam R is the polygon mirror 2
A Fresnel lens surface 6A and a Fresnel lens surface 6B are formed so as to be farthest from the document 6 and on the document 6, and the focal point gradually moves as the moving mirror 9 moves rightward in FIG. The cross-sectional shapes of the Fresnel lens surface 6A and the Fresnel lens surface 6B are set so that the positions are closer when viewed from the polygon mirror 2 (see FIG. 3B). When the light beam R is incident on the right end of the document table 6G,
Since the optical path length of the light beam R from the polygon mirror 2 to the document 6 is the shortest, at this time, the focal position of the light beam R is closest to the document 6 as viewed from the polygon mirror 2 so as to be on the document 6. Are formed with a Fresnel lens surface 6A and a Fresnel lens surface 6B.

With the above-mentioned original table 6G, the focal position of the light beam R is always on the original document 6 regardless of the movement of the movable mirror 9, and the telecentric lens 10 keeps the focal position on the original document 6 regardless of the movement of the movable mirror 9. Light beam R
Is constant, as a result, scanning is performed with the focal position of the light beam R always on the document 6 over the entire document 6.

The focal point of the light beam R in the sub-scanning direction is once converted into a parallel light beam by the first cylindrical lens 5 and then condensed on the original 6 by the second cylindrical lens 21 moving in the sub-scanning direction. Therefore, if the focal length f of the second cylindrical lens 21 is set to be equal to the distance from the second cylindrical lens 21 to the document 6, even if the movable mirror 9 moves in the sub-scanning direction, the focal point in the sub-scanning direction will not change. It is always on the document 6. (Ii) Configuration and Operation of Control Unit Next, the configuration and operation of the control unit 30 for controlling the operation of the copying machine P including the operation of the moving mirror 9 will be described with reference to FIG.
This will be described with reference to FIG.

As shown in FIG. 1, the control unit 30 includes a CPU 31 as a reading unit and a ROM (Read Only Memory).
33 and RAM (Random Access Memo) as storage means
ry) 34 and a detection circuit 32.

Next, the operation of each section will be described. Detection circuit 3
2 is a photodiode 7a included in the light receiving unit 7,
The light receiving signal Sd from 7b or 7c is received, respectively, synthesized, and output to the CPU 31.

The ROM 33 stores a control program for controlling the entire apparatus, and outputs the program to the CPU 41 as needed. The RAM 34 temporarily stores information synthesized by the CPU 41 based on the light receiving signal Sd as a read signal Sr.

When reading the original 6, the CPU 31 outputs a drive signal Sv for driving the semiconductor laser 1 to drive the semiconductor laser 1 to emit a light beam R, and the movable mirror 9 Is moved in the sub-scanning direction. In parallel with this, the CPU 31
A read signal Sr corresponding to the information to be read on the document 6 is generated based on the combined light receiving signal Sd from
It is stored in AM34.

At this time, since the light receiving section 7 is constituted by three photodiodes 7a, 7b and 7c arranged in a plane parallel to the surface of the original 6 and in a direction parallel to the main scanning direction, one light receiving section 7 is provided. The range of the reflection position on the document 6 of the reflected light to be received by the photodiode becomes narrow, in other words,
The difference in the distance of the reflected light to be received by one photodiode from the reflection position on the document 6 to the photodiode (ie, the difference in the distance to the photodiode between points within the range of the reflection position) is The light receiving signal can be read with high accuracy and uniformity because the light reflected by the light beam R from the entire surface of the document 6 is received by one photodiode. Note that the number of photodiodes constituting the light receiving unit 7 may not be three,
It is better to increase the number of photodiodes for uniformity of sensitivity.

CPU using light receiving section 7 and detection circuit 32
More specifically, the operation of the CPU 31 at the time of reading information will be described below. The CPU 31 determines the irradiation position of the light beam R when the light beam R is incident on the photodiode detector 8 as described above. It is managed as the elapsed time from the timing. That is, for example, assuming that the irradiation position of the light beam R is the end point P ₁ along the main scanning direction of the document 6 when the time T ₁ has elapsed, the time (T ₁ + Δt (Δt is the reading clock for the light beam R) When the period)) has elapsed, the light beam R
Is located at a point P ₂ adjacent to the end point P _{1 on} the main scanning direction side.
When the time (T ₁ + 2 × Δt) elapses, the point P ₃ is further adjacent to the point P ₃ . Then, the CPU 31 reads the combined value from the detection circuit 32 at each reading clock cycle, and compares the total amount (combined value) of the reflected light from the irradiation position of the light beam R at that time with a predetermined reference value. as a result,
When the combined value is larger than the reference value, the irradiation position is determined to be “white”, and when the combined value is smaller than the reference value, the irradiation position is determined to be “black”. In the case of detecting an intermediate value, a white level (a composite value when the irradiation position is “white”) and a black level (the irradiation position is “black”) are set in advance.
Are stored, and the gradation value (density value) is calculated based on the level of the composite value between the white level and the black level.

The white level / black level or gradation value data (generally referred to as pixel data) calculated as described above is used as a read signal Sr for each irradiation position in the RAM 3.
4 is stored. Then, the irradiation position is changed for each reading clock, and the pixel data is
It is stored in M34.

The end of one main scan is also recognized by the elapsed time. This is determined by the width of the main scanning area and the rotation speed of the polygon mirror 2. After the reading by one line of the main scanning is performed, the irradiation position is changed in the sub-scanning direction by a predetermined amount, and the operation of reading the original 6 by the one-line main scanning is repeated. Two-dimensional scanning is completed.

Next, RA is read by the above information reading operation.
An information recording operation for recording information stored in M34 will be described. At the time of information recording, the recording light beam G is emitted from the semiconductor laser 1 ′ at an intensity corresponding to the recorded information from the semiconductor laser 1 ′ based on the drive signal Svr from the CPU 31 based on the information stored in the RAM. .

The information referred to here may be information input from a computer or the like, or information transmitted from a facsimile, in addition to the information of the original 6 read by the above-described reading operation. And so on.

The recording light beam G emitted from the semiconductor laser 1 ′ is applied to the polygon mirror 2, and is rotated at a constant speed, so that the polygon mirror 2 rotates in a main scanning direction (parallel to the central axis of the photoconductor 20). Deflection scanning). The recording light beam G deflected and scanned in the main scanning direction reaches the dichroic mirror 4 via the first cylindrical lens 5. Thereafter, the light is reflected by the dichroic mirror 4 and condensed by the imaging lens 3 and then directed to the photoreceptor 20, and reflected by the reflection mirrors 13 and 14.
The recording light beam G reflected by the recording medium G is irradiated onto the photoconductor 20 rotated every main scanning, so that an electrostatic latent image corresponding to information (in the case of an electrophotographic system) is formed on the photoconductor 20. Be recorded. Since the information recorded on the photoconductor 20 is held as an electrostatic latent image in the case of, for example, an electrophotographic system, the electrostatic latent image is colored by a single color toner or the like (not shown). The original information (information on the document 6) is output by being transferred to a recording sheet that does not.

As for the cooperation between the information reading operation and the information recording operation, the information (read signal Sr) stored in the RAM 34 is read out every time one scan is performed in the main scanning direction in the information reading operation, and the recording light is read. Emitting the beam G and forming an electrostatic latent image corresponding to the information read in the one scan on the photosensitive member 20 may be repeated during the sub-scanning period, or may be repeated several times in the main scanning direction. Information temporarily
Each time several scans are completed, the information stored in the RAM 34 is read out, a recording light beam G is emitted, and an electrostatic latent image corresponding to the information read by the several scans is printed on the photoconductor 20. May be repeated during the sub-scanning period. Further, the entire original 6 is scanned and the original 6 is scanned.
The read signal Sr corresponding to the whole may be stored in the RAM 34, and after the scanning, an electrostatic latent image corresponding to all of the information on the document 6 may be collectively formed on the photoconductor 20.

As described above, the copying machine P of the embodiment
According to the method, since the light beam R is scanned in the main scanning direction by the polygon mirror 2 and the moving mirror 9 is moved to perform scanning in the sub-scanning direction, the polygon mirror 9 does not need to be moved. As compared with the case where the laser beam itself is moved in the sub-scanning direction, it is possible to eliminate the influence of vibration or the like on the polygon mirror 9 on scanning.

Further, the light beam R is emitted from the document table 6G on which the Fresnel lens surface 6A and the Fresnel lens surface 6B are formed.
Since the focus in the main scanning direction is always on the document 6,
The light beam R can be focused on the document 6 with a simple configuration.

Further, since the scanning width of the original 6 in the main scanning direction is fixed by the telecentric lens 10, the configuration of the copying machine P can be further simplified. Furthermore,
Since the Fresnel lens surface 6A and the Fresnel lens surface 6B are formed in the document table 6G, the configuration of the copying machine P can be further simplified.

The light beam R is converted into a parallel light beam in the sub-scanning direction by the first cylindrical lens 5, and the light beam R converted into a parallel light beam by the second cylindrical lens 21 in the movable mirror 9 is placed on the original 6. Therefore, even if the moving mirror 9 moves in the sub-scanning direction, the light beam R can be condensed on the document 6 in the sub-scanning direction.

Further, since the second cylindrical lens 21 for condensing the light beam R in the sub-scanning direction is arranged in the movable mirror 9 close to the original 6, the so-called surface tilt on the reflection surface of the polygon mirror 2 (polygon mirror) 2 is not parallel to the plane including the rotation axis of the polygon mirror 2), it is possible to effectively compensate for the fluctuation of the light beam R in the sub-scanning direction.

Further, since the light receiving section 7 is composed of the three photodiodes 7a, 7b and 7c for receiving the reflected light, the level of the light receiving signal Sd can be increased, and the information on the document 6 can be accurately detected. Can be read.

Further, the information on the original 6 is scanned with high accuracy,
The reflected light of the light beam R is received by the light receiving unit 7 to generate a light receiving signal Sd, and a corresponding read signal Sr is output, so that the information can be read with high accuracy.

Further, since the information read by scanning with high precision can be held on the photosensitive member 20, the read information can be recorded accurately and reliably.

In the above embodiment, the light beam R for reading information and the recording light beam G for recording information are emitted from separate semiconductor lasers. However, the present invention is not limited to this. After scanning all the information above, the photoconductor 20
In a copying machine that records on a single light source, a light beam from a single semiconductor laser is used as the light beam R during information reading, and the light beam is used as the recording light beam G during information recording. Is also good.

Further, in recent years, a semiconductor laser capable of emitting light beams having a plurality of different oscillation wavelengths from one semiconductor laser has been developed. In the present invention, such a semiconductor laser is also used. The light beam R and the recording light beam G can be emitted from one semiconductor laser.

In the above embodiment, the case where the present invention is applied to the copying machine P has been described. However, the present invention is not limited to this, and the present invention can be applied to a so-called scanner device for reading information on the original 6. It is. In this case,
From the configuration of the copying machine P to the configuration of the information recording system (more specifically, the semiconductor laser unit 12, the dichroic mirrors 4 and D, the imaging lens 3, the reflection mirrors 13 and 14,
The configuration may be such that the photoconductor 20) is omitted.

[0070]

As described above, according to the first aspect of the present invention, the light beam is scanned in the main scanning direction by the deflection scanning means, and the scanning in the sub scanning direction is performed by moving the moving mirror means. Therefore, it is not necessary to move the deflection scanning means itself, and it is possible to eliminate the influence of the vibration and the like of the deflection scanning means on the scanning as compared with the case where the deflection scanning means itself is moved in the sub-scanning direction.

Further, since the scanning width in the main scanning direction on the recording medium is made constant by the scanning width fixing means, and the focal position of the light beam is set on the recording medium by the focal position changing means, the moving mirror means moves. Even in this case, it is possible to accurately scan the recording medium at a constant width.

Therefore, information can be scanned with high accuracy. According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, the focal position changing means is arranged on the optical path of the light beam between the moving mirror means and the recording medium, and Since it is a Fresnel pair lens including a positive lens and a negative lens, which are Fresnel lenses having a refractive power only in the scanning direction, the configuration of the focal position changing unit can be simplified.

Therefore, the configuration of the entire optical scanning device can be simplified. According to the third aspect of the invention, in addition to the effects of the first or second aspect of the invention, the configuration of the optical scanning device can be simplified since the scanning width stabilizing means is a telecentric lens. .

According to the invention set forth in claim 4, according to claim 2,
In addition to the effects of the invention described in (1), since the Fresnel pair lens also serves as the mounting table on which the recording medium is mounted, the configuration of the entire optical scanning device can be further simplified.

According to the invention set forth in claim 5, claim 1 is provided.
In addition to the effects of the invention described in any one of (4) to (4), the light beam deflected and scanned in the sub-scanning direction by the first cylindrical lens is converted into a parallel light beam, and further converted by the second cylindrical lens in the moving mirror means. Since the light beam converted into a parallel light beam is focused on the recording medium, the configuration of the light focusing means can be simplified, and the light beam is recorded in the sub-scanning direction even if the moving mirror means moves in the sub-scanning direction. Light can be collected on the medium.

According to the invention set forth in claim 6, according to claim 1,
5. In addition to the effects of the invention described in any one of the above items 5, the information on the recording medium is scanned with high accuracy, and the light receiving unit receives the reflected light of the light beam to generate a light receiving signal. Since the corresponding read signal is output, the information can be read with high accuracy.

According to the invention of claim 7, according to claim 6,
In addition to the effect of the invention described in the above, the light receiving means is arranged such that a plurality of light receiving elements for receiving the reflected light are arranged in a plane parallel to the information recording surface of the recording medium and in a direction parallel to the main scanning direction. Therefore, the level of the light receiving signal can be increased, and the information on the recording medium can be read with high accuracy.

According to the invention of claim 8, according to claim 6,
Or, in addition to the effect of the invention described in 7, since the information read by scanning with high accuracy can be held, the read information can be recorded accurately and reliably.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a copying machine according to an embodiment.

FIG. 2 is a plan view illustrating a detailed configuration of an optical scanning unit according to the embodiment.

3A and 3B are diagrams illustrating a configuration and an operation of the copying machine according to the embodiment; FIG. 3A is a side cross-sectional view of the copying machine according to the embodiment;
FIG. 2B is a side cross-sectional view of the document table of the embodiment, and FIG.
FIG. 3 is a cross-sectional view taken along line AA ′ of the document table of the embodiment.

[Explanation of symbols]

 1, 1 ′ semiconductor laser 2 polygon mirror 3 imaging lens 4, D dichroic mirror 5 first cylindrical lens 6 original 6G original plate 6A, 6B Fresnel lens surface 7 light receiving parts 7a, 7b 7c Photodiode 8 Photodiode detector 9 Moving mirror 9A, 13, 14, MR Reflective mirror 9B Detection lens 10 Telecentric lens 11, 12 Semiconductor laser unit 20 Photoconductor 21 Second cylindrical lens 30 ... Control unit 31 ... CPU 32 ... Detection circuit 33 ... ROM 34 ... RAM P ... Copier S ... Optical scanning unit R ... Light beam G ... Recording light beam C ... Collimator lens E ... Cylindrical lens M ... Aperture BD ... Housing Sd: light receiving signal Sr: reading signal Sp: sensor signal

Claims (8)

[Claims] An emission unit for emitting a light beam; a deflection scanning unit for deflecting and scanning the emitted light beam in a main scanning direction on a recording medium on which information to be scanned is recorded; Converging the light beam in the main scanning direction, and making the scanning width of the light beam in the main scanning direction on the recording medium a constant width that is set in advance in accordance with the recording medium. Means for condensing the deflected and scanned light beam in a sub-scanning direction perpendicular to the main scanning direction; and moving the light beam in the sub-scanning direction while reflecting the collected light beam. Moving mirror means for irradiating the condensed light beam onto the recording medium; and changing a distance from the deflection scanning means to a focal position of the light beam in response to movement of the moving mirror means in the sub-scanning direction. And the said An optical scanning apparatus characterized by and a focus position changing means for the point position and on the recording medium. 2. The optical scanning device according to claim 1, wherein the focus position changing unit is disposed on an optical path of the light beam between the moving mirror unit and the recording medium, and is arranged in the main scanning direction. An optical scanning device comprising: a Fresnel pair lens including a positive lens and a negative lens, which are Fresnel lenses having only refractive power. 3. The optical scanning device according to claim 1, wherein the scanning width stabilizing unit makes the principal rays of the respective light beams after the deflection scanning parallel to each other, and sets the scanning direction on the recording medium. An optical scanning device, characterized in that the optical scanning device is a telecentric lens that sets the scanning width of the light beam to the constant width. 4. The optical scanning device according to claim 2, wherein the Fresnel pair lens is a mounting table on which the recording medium is mounted. 5. The optical scanning device according to claim 1, wherein the light condensing unit is arranged on an optical path of the light beam between the deflection scanning unit and the scanning width fixing unit. And a light beam that is deflected and scanned in the sub-scanning direction into a parallel light beam.
A cylindrical lens; a second cylindrical lens disposed in the moving mirror means, moving in the sub-scanning direction together with the moving mirror means, and condensing the light beam converted into the parallel light beam on the recording medium. An optical scanning device, comprising: 6. The optical scanning device according to claim 1, wherein the light beam moves integrally with the moving mirror unit and is applied to the recording medium by the moving mirror unit. An optical information reading apparatus, comprising: a light receiving unit that receives the reflected light and outputs a light receiving signal; and a reading unit that outputs a reading signal corresponding to the information based on the light receiving signal. 7. The optical scanning device according to claim 6, wherein the light receiving unit includes a plurality of light receiving elements that receive the reflected light in a plane parallel to a recording surface of the information on the recording medium. An optical information reading device, which is arranged in a direction parallel to the main scanning direction. 8. An optical information reading device according to claim 6, wherein a storage means for storing the read signal; and a recording light beam corresponding to the information based on the stored read signal. A recording light beam emitting unit that emits the light to the deflection scanning unit; and a recording light beam that condenses the recording light beam onto the information holding unit that holds the information. An optical information recording device, comprising: a guiding unit for guiding to a beam focusing unit.