JPH10142905A - Scanning optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recognize a read object placed on an original placing surface of an original platen and to intercept a light beam from a light source even in the case of provision of a pressing cover by providing a cover member which selectively transmits light other than luminous flux from the light source in the incident area of the luminous flux from the light source. SOLUTION: The pressing cover 4 to cover the original platen 3 is provided freely openable/closable through a hinge, etc., and intercepts the light beam and presses a book, etc., from an upside in a state where it covers over the original platen 3. The area of the cover 4 equivalent to the original placing area of the original platen 3 is formed of a polarizing filter 7 functioning as a light selecting member, and the original placed on the original platen 3 is recognized even in a state where the cover 4 is closed. The filter 7 is constituted of a wire grid polarizer, and it does not transmit only laser luminous flux polarized in a perpendicular axis direction regardless of wavelength but selectively transmits other light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the technical field of a scanning optical device for scanning a document with a light source such as a laser.

[0002]

2. Description of the Related Art Conventionally, in a scanning optical device for reading an image provided in a copying machine or the like, an object to be read, such as a print original, is placed on a plate-like original placing surface, and On the other hand, a light beam from a light source is deflected and scanned by a polygon mirror to irradiate the light beam, and the reflected light from the object to be read is received by a light receiving means such as a photodetector. Image information corresponding to the object to be read that has been irradiated.

The document placing surface is usually formed of a transparent material such as glass, and the light beam is irradiated over the entire area of the document placing surface. Outside the mounting area, there is nothing blocking the light beam, and the light beam directly enters the user's eyes.

Therefore, conventionally, an opaque holding cover that covers the entire original placing surface and does not allow the light beam to pass therethrough is provided on the original placing surface so as to be openable and closable. The object to be read is placed on the document placing surface, and reading is executed in a state where the object to be read is pressed by the holding lid.

[0005]

However, since the light other than the light beam from the light source is blocked by the holding lid in the conventional scanning optical device, the position of the mounted reading object is confirmed. As a result, the reading may be executed with the position shifted.

The only way to prevent this is to perform reading with the holding lid open. However, when a laser is used as the light source, the linearity and the energy density are high. It is dangerous if the light directly enters the user's eyes, so it is necessary to execute reading with the holding lid closed.

In the case of an object to be read such as a book having a large thickness, it is necessary to press the object to be read with the holding cover in order to bring the reading surface into close contact with the document placing surface. Was an essential member.

Therefore, the present invention solves the above problems,
Provided is a scanning optical device capable of recognizing an object to be read placed on a document placing surface of a document table, and also capable of intercepting a light beam from a light source, even when the press cover is provided. It is an issue.

[0009]

According to a first aspect of the present invention, there is provided a scanning optical device, comprising: a document table on which a document is placed; a light source for irradiating light of a predetermined wavelength; A deflector for deflecting and scanning the light beam from the light source, a light condensing means for condensing the light beam deflected and scanned by the deflector and causing the light beam to enter the document placed on the document table; and Light-receiving means for receiving the scattered light of the original and reading image information on the original, and a cover member for covering the original mounting surface of the original plate, and at least an incident area of the light beam from the light source on the original plate. And a lid member formed of a light selection member that selectively transmits light other than the light flux from the light source.

According to the scanning optical device of the first aspect,
The light beam of a predetermined wavelength emitted from the light source is deflected and scanned by the deflector, condensed by the light condensing means, and made incident on a document placed on a document table. Then, image information on the document is read by receiving light scattered from the document by the light receiving means. On the other hand, when such reading is performed, the document is placed on a platen,
Although it is covered by the lid member, a region corresponding to the incident area of the light beam from the light source in the lid member is formed by a light selection member, and selectively transmits light other than the light beam from the light source. . Therefore, the original is recognized from the outside of the lid member, and the light beam from the light source is blocked.

According to a second aspect of the present invention, in the scanning optical device according to the first aspect, the light selecting member has a transmission axis perpendicular to at least a polarization direction of a light beam from the light source. It is a polarizing filter.

According to the scanning optical device of the second aspect,
By using a polarizing filter having a transmission axis perpendicular to at least the polarization direction of the light beam from the light source as the light selecting member, the light beam is blocked by the light selecting member regardless of the wavelength of the light beam from the light source.

According to a third aspect of the present invention, in the scanning optical device according to the first aspect, the light selecting member is a reflection type filter that reflects at least a light beam from the light source. I do.

According to the scanning optical device of the third aspect,
By using a reflection filter that reflects at least the light beam from the light source as the light selection member, the light beam from the light source is surely reflected and blocked.

According to a fourth aspect of the present invention, in the scanning optical device according to the first aspect, the light selecting member is an absorption filter that absorbs at least a light beam from the light source. I do.

According to the scanning optical device of the fourth aspect,
By using an absorption filter that absorbs at least the light beam from the light source as the light selection member, the light beam from the light source is reliably absorbed and blocked.

A scanning optical device according to a fifth aspect of the present invention is the scanning optical device according to any one of the first to fourth aspects, wherein the light source is a laser that emits a light beam with directivity. It is characterized by.

According to the scanning optical device of the fifth aspect,
By using a laser that emits a luminous flux with directivity as the light source, high-precision images can be obtained while reliably preventing the risk that laser light is incident on the user's eyes by the light selection member of the lid member. And digital processing of the read information is performed.

According to a sixth aspect of the present invention, in the scanning optical device according to the fifth aspect, the laser is a plurality of lasers having different oscillation wavelengths.

According to the scanning optical device of the sixth aspect,
By using a plurality of lasers having different oscillation wavelengths as the laser, the laser is formed in a plurality of colors while reliably preventing the risk that laser light is incident on the user's eyes by the light selection member of the lid member. The read image is accurately read.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a cross-sectional view illustrating a schematic configuration of a laser copying apparatus 1 including a scanning optical device according to an embodiment of the present invention. In FIG. 1, the laser copying apparatus 1 includes a main body case 2, a document placing section 5 for placing a document, and a sheet feeder section for feeding a sheet P as an example of a recording medium for image formation. 1
0, a latent image forming unit 20 in which steps of reading, charging, exposing, and the like of a document image for image formation are sequentially performed, and a latent image formed by the latent image forming unit 20 is converted into a visible image by a developer. Developing section 60, a transfer section 70 for transferring the developer image developed by the developing section 60 to the sheet P, and fixing the transfer image transferred by the transfer section 70 to the sheet P. And a discharge tray 90 for discharging the paper P on which the image has been fixed along the transport path PP.

The latent image forming unit 20 includes a photosensitive drum 21 as an example of a photosensitive member, and a charge removing lamp 2 for removing a residual potential remaining on the photosensitive drum 21 after transfer.
2, a charger 23 for charging the photosensitive drum 21 so as to form an electrostatic latent image, and an exposure for scanning and reading a document image and forming an electrostatic latent image on the photosensitive drum 21. The laser scanner unit 24 and the frame 25
The latent image forming unit 20 is provided so as to be capable of reciprocating in the left-right direction in FIG. 1 by a driving mechanism (not shown).

The original placing section 5 includes an original table 3 made of a transparent material such as glass for placing an original,
And a press cover 4 as a cover member for covering the cover. The press cover 4 is provided at the back side in FIG.

Further, when the latent image forming unit 20 is stopped at the position indicated by the solid line in FIG. 1, the developing unit 60 is provided with a cyan developing device which is provided so as to be able to approach or retreat from the photosensitive drum 21. 61, magenta developing device 62,
A yellow developing unit 63 is provided.

Next, each component constituting the laser copying apparatus 1 will be described in detail. In FIG. 1, the paper feeder unit 10 includes a paper feed cassette 11 which is detachably disposed below the main body case 2, and urges the paper P upward at the bottom of the paper feed cassette 11. A paper pressing plate (not shown) is provided. A paper feed roller 12 extending from the near side to the far side in FIG. 1 is formed above the paper feed cassette 11 so as to contact the paper P urged by the paper pressing plate, and The paper feed roller 12 is configured to be rotatably supported at a predetermined paper feed timing by a drive system (not shown). Therefore, the sheets P stored in the sheet cassette 11 are fed one by one from the upper side. In order to prevent double feeding of the paper P, a separating member elastically biased to the paper feed roller 12 by a compression spring may be provided below the paper feed roller 12. Further, a transport roller pair 13 for transporting the paper P and a fed paper P
A pair of registration rollers 14, which align the leading ends of the rollers, are rotatably supported respectively.

Next, the photosensitive drum 21 as an example of the photosensitive member provided in the latent image forming unit 20 is made of, for example, an organic photosensitive member mainly composed of positively charged polycarbonate. More specifically, the photosensitive drum 21 has, for example, a cylindrical aluminum sleeve as a main body and a predetermined thickness (for example, about 20 μm) in which a photoconductive resin is dispersed in polycarbonate on an outer peripheral portion thereof. And is rotatably supported by the main body case 2 with the cylindrical sleeve grounded. In other words, the positively charged (positively charged) electrostatic latent image formed on the photosensitive drum 21 is developed with the positively charged toner by the reversal developing method. The photosensitive drum 21 is configured to be driven to rotate clockwise in a side view by a driving unit (not shown).

The static elimination lamp 22 includes a light source such as an LED (light emitting diode), an EL (Electro Luminescence), a fluorescent lamp, etc., and irradiates light remaining on the photosensitive drum 21 with light after transfer. To remove (discharge). Thus, it is possible to prevent the remaining charge from affecting the next electrostatic latent image and finally appearing on the image formed on the sheet P.

The charger 23 is composed of a scorotron-type charger for positive charging for generating corona discharge from a charging wire made of, for example, tungsten or the like. In the present embodiment, the cleanerless system is adopted,
Numeral 3 is arranged so as to face the photosensitive drum 21 in a non-contact manner, so that the residual toner on the photosensitive drum 21 does not adhere to the charger 23.

The laser scanner unit 24 is disposed above the photosensitive drum 21 and has the following configuration. As shown in FIG. 2, a red semiconductor laser 2 is provided on a scanner frame 26 of the laser scanner unit 24.
7, a green semiconductor laser unit 34 including a green semiconductor laser 31, and a blue semiconductor laser unit 3 including a blue semiconductor laser 35.
8 are provided as a document reading light source. The red semiconductor laser 27 has a wavelength of 600 to 700 n.
m, but in this embodiment, 6
The one having a wavelength of 50 nm is used. As the green semiconductor laser 31 and the blue semiconductor laser 35, those having wavelengths of 500 to 600 nm and 400 to 500 nm, respectively, can be used.
nm and 450 nm. Furthermore,
As a recording light source, a near-infrared semiconductor laser unit 4 including a near-infrared semiconductor laser 39 with a wavelength of 780 nm
2 are provided.

The optical axes of the red semiconductor laser 27, the green semiconductor laser 31, and the blue semiconductor laser 35, which are reading lasers, are near the infrared laser 3, which is a recording laser.
The dichroic mirrors 43, 44, 45 for transmitting or reflecting light of a specific wavelength are located at intersections of the respective optical axes.
Is provided.

A dichroic mirror 4 on which a near infrared light beam L for recording and a blue light beam B for reading are incident.
Reference numeral 5 has a characteristic of reflecting the blue light beam B and transmitting the near-infrared light beam L, and these beams have the same optical path. The dichroic mirror 44, into which the near-infrared light beam L or blue light beam B and the reading green light beam G are incident, reflects the green light beam G and simultaneously transmits the near-infrared light beam L or It has the property of transmitting the blue light beam B, and these beams have the same optical path. Further, the near-infrared light beam L or blue light beam B or green light beam G
And the dichroic mirror 43, into which the red light beam R is incident, has a property of transmitting the red light beam R and reflecting the near-infrared light beam L or the blue light beam B or the green light beam G. These beams have the same optical path.

That is, the red light beam R enters the dichroic mirror 43 via the collimator lens 28 for making the light flux substantially parallel and the stop 29 for making the spot diameter a predetermined size.
And reaches the cylindrical lens 46. The green light beam G passes through a dichroic mirror 4 via a collimator lens 32 for making the light flux substantially parallel and a diaphragm 33 for making the spot diameter a predetermined size.
4, is reflected by the dichroic mirror 44 and is incident on the dichroic mirror 43, is reflected by the dichroic mirror 43 and follows the same optical path as the red light beam R to reach the cylindrical lens 46. Further, the blue light beam B is incident on a dichroic mirror 45 via a collimating lens 36 for making the light flux substantially parallel and a stop 37 for making the spot diameter a predetermined size, and is reflected by the dichroic mirror 45. Incident on the dichroic mirror 44, is transmitted by the dichroic mirror 44, is incident on the dichroic mirror 43, and is reflected by the dichroic mirror 43 to follow the same optical path as the red light beam R and the green light beam G. It reaches the cylindrical lens 46. The near-infrared light beam L for recording is incident on a dichroic mirror 45 via a collimator lens 40 for making the light flux substantially parallel and a diaphragm 41 for making the spot diameter a predetermined size. The light is transmitted by the mirror 45 and is incident on the dichroic mirror 44. The light is transmitted by the dichroic mirror 44 and is transmitted by the dichroic mirror 4.
3 and is reflected by the dichroic mirror 43 to reach the cylindrical lens 46 along the same optical path as the red light beam R, the green light beam G, and the blue light beam B.

The cylindrical lens 46 is a lens for converging a light beam in only one direction, and the respective light beams serve as deflectors disposed at the focal position of the cylindrical lens 46 via the cylindrical lens 46. Into the regular hexagonal polygon mirror 47. When the polygon mirror 47 rotates at a constant speed, the polygon mirror 47 is rotated.
2. Any one of the red light beam R, the green light beam G, the blue light beam B, or the near-infrared light beam L incident on the surface is scanned at a constant speed in a direction parallel to the plane of FIG. The light is condensed by the image lens 48 and further directed by the dichroic mirror 49 and the reflection mirror 50.

The dichroic mirror 49 and the reflection mirror 50 are provided in front of the imaging lens 48, as shown in FIG. And dichroic mirror 4
9 transmits the near infrared light beam L for recording,
The red light beam R, the green light beam G, or the blue light beam B for reading is reflected, and the document 6 on the document table 3 is irradiated with these reading light beams. The reflection mirror 50 reflects the near-infrared light beam L for recording transmitted by the dichroic mirror 49 and irradiates the near-infrared light beam L onto the photosensitive drum 21.

As shown in FIG. 2, a BD mirror 51 for reflecting a recording light beam emitted from the semiconductor laser 39 is provided at a position in the scanner frame 26 corresponding to a position outside the irradiation area of the photosensitive drum 21. And B for detecting a light beam reflected by the BD mirror 51 and forming a horizontal synchronization signal.
A D sensor 52 is provided.

Further, as shown in FIGS. 1 and 3, a light detecting lens 53 for detecting a light beam scattered and reflected by the original 6 is provided at a position opposed to the original 6 with the original table 3 interposed therebetween.
In addition, three photodetectors 54 as light receiving means including photodiodes, which are well-known photoelectric conversion elements, are provided at equal intervals in a direction parallel to the light beam scanning direction (see FIG. 4). The number of the photodetectors 54 is not limited to three, but may be more (for example, seven). By providing a large number of photodetectors in this way, it is possible to reduce unevenness in sensitivity of the photodetectors. In addition, the position of the document table 3, that is, the mounting surface of the document 6, is set to coincide with the focal position of the imaging lens 48, and is optically conjugate with the position of the photosensitive drum 21.
The spot diameter of the light beam scanning on the photosensitive drum 21 and the spot diameter scanning on the document 53 become equal. Therefore,
The accuracy at the time of document recording and the accuracy at the time of image reading become equal, and the image on the document 6 can be faithfully reproduced on the photosensitive drum 21.

The latent image forming unit 20 having the above-described configuration is provided so as to be reciprocally movable in a direction indicated by an arrow in FIG. 1 and in a direction opposite thereto by a driving mechanism (not shown). Then, the photosensitive drum 21 is exposed in the sub-scanning direction. Specifically, the latent image forming unit 20 has a home position at a position indicated by a solid line in FIG. 1, and reads from the home position using the red light beam R as the first color and a near red light corresponding to the reading. Exposure with the external light beam L is started. Then, while rotating the photosensitive drum 21 at a predetermined timing, the latent image forming unit 20 is moved at a predetermined timing in the sub-scanning direction indicated by an arrow in FIG.
The reading and exposure by the first color are completed by moving to the position shown by the two-dot chain line. Thereafter, the latent image forming unit 20 returns to the home position indicated by the solid line in FIG. 1 while rotating the photosensitive drum 21 at a predetermined timing, and the cyan developing device 6 described below.
1A develops. Hereinafter, in the same manner, in order to perform reading with the green light beam G as the second color and the blue light beam B as the third color, exposure with the corresponding near-infrared light beam, and development corresponding thereto. Then, the latent image forming unit 20 is reciprocated.

Accordingly, during the copying operation, the red light beam R, the green light beam G, and the blue light beam B are emitted through the document table 3, so that these light beams are prevented from entering the user's eyes. It is necessary to cover the original mounting surface of the table 3, and in the case of a thick book or the like, it is necessary to press the book or the like from above in order to maintain the flatness of the original surface.

Therefore, in the apparatus of this embodiment, the document table 3
A cover 4 for covering the document table is provided so as to be openable and closable by a hinge or the like. When the document cover 3 is covered as shown in FIG. 1, the light beam can be blocked and the book or the like can be pressed from above. Will be possible.

Then, the holding lid 4 in this embodiment is
As shown in FIG. 5A, a region corresponding to a document placing region of the document table 3 is formed by a polarizing filter 7 as a light selection member. As shown in FIG. Even when the document is closed, the document placed on the document table 3 can be recognized. FIG. 5B shows a state in which the holding lid 4 is opened.

This polarizing filter is composed of a wire grid polarizer 8 as shown in FIG. 6, and makes only a laser beam polarized in the y-axis direction shown in FIG. 6 opaque regardless of the wavelength. It selectively transmits other light that vibrates in the E direction. An example of such a wire grid polarizer 8 is a plate obtained by dispersing a needle-like crystal having a wavelength of about Herapatite in aluminum acetate of acetylcellulose into a plate shape (trade name: polaroid). Further, a fine crystal of iodine may be adsorbed on a film of a chain molecule such as cellulose to align the directions (trade name: dichrom).

FIG. 7 shows a polarizing filter 7 according to this embodiment.
Shows the transmission characteristics of As shown in FIG. 7, the polarization filter 7 of the present embodiment has a wavelength of 435 nm to 470 nm and 535 nm.
570 nm and 635 nm to 670 nm. Therefore, the wavelength of the blue light beam B used in this embodiment is 450
nm, the wavelength of the green light beam G is 550 nm, and the wavelength of the red light beam R is 650 nm. Therefore, even if these wavelengths fluctuate due to variations in semiconductor laser products or changes in temperature, these light beams can be reliably transmitted. Opaque,
Transmits light of other wavelengths. As a result, it is possible to prevent the danger of the laser light being incident on the user's eyes and to make sure that the original is confirmed.

Next, the structure of the developing unit 60 driven after the above-described safe reading of the image by the holding lid 4 and the corresponding exposure are performed will be described. The developing unit 60 includes, as shown in FIG.
0 is located below the photosensitive drum 21 when it is at the home position.
A cyan developing device 61, a magenta developing device 62, and a yellow developing device 63 each including a developing roller 1A, a developing roller 62A, and a developing roller 63A are provided. Each developing roller 61A, 6
A power supply (not shown) for supplying a voltage for development is connected to 2A and 63A, and a controller (not shown) supplies the voltage for development when the developing rollers 61A, 62A and 63A operate. (Not shown).

In each of the developing devices 61, 62 and 63,
Positively charged cyan toner, magenta toner, and yellow toner, respectively, are housed together with the magnetic carrier,
Each toner is supplied to each of the developing rollers 61A, 62A, and 63A. The toner in the exemplary embodiment is a positively-chargeable toner, and is, for example, a non-magnetic toner composed of a pulverized toner or a polymerized toner composed of styrene acrylic having a nearly spherical shape, and a coloring agent such as a magenta or cyan or yellow pigment. And a binder resin such as a polyester resin. As a result, most of the toner is supplied to the developing rollers 61A, 62A, 6A.
3A, plus (positive) after being rubbed by the photosensitive drum 21 or the like
It is charged to polarity.

Further, each of the developing units 61, 62 and 63 is a
Are provided so as to be reciprocally movable in the directions indicated by the arrows, and each developing device can contact each developing roller with the photosensitive drum 21 at a predetermined timing. Each developing roller is
In order to form a nip portion at a developing position in contact with the photosensitive drum 21, the nip portion is formed of a conductive rigid roller made of silicon rubber, urethane rubber, or the like. In the present embodiment, for example, since the photosensitive drum 21 having the organic photosensitive layer mainly composed of the positively charged toner and the positively charged polycarbonate is used, urethane rubber is used as a material of each developing roller.

Next, on the downstream side in the moving direction of the photosensitive drum 21 from the contact portion between each developing roller and the photosensitive drum 21 as described above, similarly to the charger 23, for example, tungsten or the like is used. A scorotron-type transfer charger 71 and a separation charger 72 for positive charging for generating corona discharge from the charging wire are provided.

A fixing unit 80 is provided downstream of the separation charger 72 in the transport direction of the paper P. Fixing unit 8
Reference numeral 0 denotes a heating roller 8 having a well-known halogen lamp.
1 and a pressing roller 82, the toner image transferred onto the upper surface of the sheet P is pressed while being heated and fixed on the sheet P.

Further, a pair of transport rollers 83 for transporting the sheet P is located downstream of the fixing section 80 in the direction of transport of the sheet P.
And a paper discharge tray 90 for guiding the paper P discharged from the fixing unit 80 to the outside of the copying apparatus for mounting.

Next, the operation of the laser copying apparatus 1 configured as described above will be described with reference to FIGS. First, the original 6 (not shown in FIG. 5) is placed on the original platen 3 with the holding lid 4 opened as shown in FIG. 5B, and the holding lid is placed as shown in FIG. Close 4. At this time,
As described above, since the polarizing filter 7 of the holding lid 4 transmits light beams other than the laser light beam, the user can recognize the placed document 6. Therefore, when the position of the document 6 is shifted, the holding cover 4 is closed again after correcting the position correctly, and the copy start key is pressed on an operation panel (not shown) provided on the upper surface of the laser copying apparatus 1. .

As a result, first, the red semiconductor laser 27,
The green semiconductor laser 31 and the blue semiconductor laser 35 emit light, and the red light beam R, the green light beam G, and the blue light beam B
Is irradiated from a laser scanner unit 24 onto a white plate (not shown) (which uniformly develops white). Then, the reflected light from the white plate is detected by the photodetector 54, and the emission intensity of each semiconductor laser is adjusted so that the reflected light intensity becomes equal to each other, so-called white level setting is performed. In this white level setting, the reflected light intensity of each semiconductor laser may be recognized as the white level of each semiconductor laser as it is.

When the white level is set, first, the red semiconductor laser 27 emits light, and the dichroic mirror 43
By the operation of the polygon mirror 47, the imaging lens 48, and the dichroic mirror 49, the red light beam R is applied to the surface of the document 6. The timing of light emission of the red semiconductor laser 27, the green semiconductor laser 31, and the blue semiconductor laser 35 is determined by a timing control circuit 57 shown in FIG.
And the driving circuit 58 emits light at the light emission timing. FIG. 9 shows this red semiconductor laser 2
7 shows a light emission timing 7 and an intensity distribution of an irradiation spot array of each light beam on the document 6. Although FIG. 9 shows the red semiconductor laser 27 as an example, other semiconductor lasers have the same light emission timing and intensity distribution. As shown in FIG. 9, the red semiconductor laser 27 corresponds to one dot corresponding to one dot in image recording.
Light is emitted at a period of a dot clock (indicated by a symbol T in FIG. 9), and has a one-dot width indicated by a symbol Δ in FIG.

Next, when the reflected light from the original 6 in response to the light beam irradiation as described above is detected by the photodetector 54, this detection signal is input to the modulation circuit 56 shown in FIG. In the circuit, the amount of attenuation of the reflected light of the red light beam R from the white level is calculated based on the detection signal, and the calculated amount of attenuation is emitted for each dot corresponding to one dot in image recording. Is replaced by the density difference from the white level of the portion where the image is formed in the color of each light beam. Further, when all scans in the main scanning direction are completed, the density difference replaced as described above is
The image is stored in the memory 55 as image information expressed by the color density of the printing color for each dot.

In this embodiment, as shown in FIG. 4, three light detecting lenses 53 and three light detectors 54 are arranged so as to divide the image reading width of the original 6 equally. The document 6 and the photodetector 54 are optically conjugate to each other with respect to the photodetection lens 53. The imaging magnification of the light detection lens 53 is determined according to the size of the photodetector 54. For example, the width of the A4 size document in the short direction (210 mm) is scanned, and the reflection from the document 6 is performed. When the light beam is detected by the three photodetectors 54, the width detected by one photodetector 54 is 70 mm. Therefore, if the width of one photodetector 54 is 5 mm, the imaging magnification becomes It may be 1/14. The signals of the photodetectors 54 arranged as described above are added together, and by detecting a light beam whose amount of light reflected in accordance with the image of the document 6 has changed, the two-dimensional image of the document 6 is converted into a time-series signal. Can be read.

The modulation circuit 56 modulates a signal based on the image information stored in the memory 55, and in accordance with the signal, records the near-infrared semiconductor laser 3 for recording.
9 irradiates a near-infrared light beam L. The light beam L is reflected toward the photosensitive drum 21 by the dichroic mirrors 45, 44, 43, the polygon mirror 47, and the reflecting mirror 50, and the light beam L is irradiated onto the photosensitive drum 21. Irradiate the surface.

FIG. 10 shows the operation timing of the reading semiconductor laser and the recording semiconductor laser. As shown in FIG. 10, the recording semiconductor laser 39 includes a BD sensor 52
The light beam is turned at prior time T _p to be incident on. At this time, the reading semiconductor laser (for example, the red semiconductor laser 27) is turned off to improve the timing accuracy. With the rotation of the polygon mirror 47,
When a light beam from the recording semiconductor laser 39 is incident on the BD sensor 52 and a BD signal is detected, a reference time T for one scan is set.
_{Although 0} is set and the recording semiconductor laser 39 is turned off once, the reading semiconductor laser is turned on at a time T _rs after a lapse of a certain time after the light is turned off, and similarly, at a time T _s after a certain time lapse, the recording semiconductor laser 39 is turned off. 39 is modulated and driven according to the image information stored in the memory 55 as described above. Here, the relationship between the times T _rs and T _s is determined by the photodetector 54.
This is the time including the delay from the input of the read signal obtained in the above to the modulation circuit 56 to the modulation of the recording semiconductor laser 39. At time T _re and T _e in accordance with the scanning of the subsequent image region (for example A4 210 mm is the breadth), the semiconductor laser for reading is turned off. And
This operation is repeated for each scan.

On the other hand, before the irradiation of the light beam L for recording as described above, after the residual charges on the photosensitive drum 21 are wiped out by the discharging lamp 22 at a predetermined timing, the surface of the photosensitive drum 21 is removed. , Charger 23 for positive charging
As a result, it is uniformly charged to a predetermined potential. In this state,
The recording light beam L irradiated as described above is irradiated on the photosensitive drum 21, and an electrostatic latent image corresponding to the image read by the red light beam is formed on the photosensitive drum 21.

Such processing is performed in the main scanning direction.
When scanning is performed for the number of scanning lines, the timing control circuit 57
By controlling the drive circuit 59 of the latent image forming unit 20, the latent image forming unit 20 is moved in the sub-scanning direction,
Reading and exposure of an image in the next scanning line are performed. However, in order to read an image area to be scanned for each scan in a consistent manner, it is necessary to align read start positions. Also, when the recording semiconductor laser 39 is driven to expose the photosensitive drum 21, the control for aligning the recording start positions is required in the same manner. Usually, in order to perform these controls, the timing is controlled using the BD sensor 52. That is, the timing control of the reading operation and the recording operation can be realized by inputting the signal obtained from the BD sensor 52 to the timing control circuit 57 and aligning the signal generation timings of the drive circuit 58 and the modulation circuit 56.

More specifically, as shown in FIG. 2, of the light beams deflected and scanned according to the rotation of the polygon mirror 47,
The light flux shown by the two-dot chain line before the image area shown by the one-dot chain line is reflected by the BD mirror 51 and made incident on the BD sensor 52 to obtain the BD signal, thereby detecting the image start position for each scan. is there.

Then, when the latent image forming unit 20 moves to the position shown by the two-dot chain line in FIG. 1 to read the image with the red light beam R in the sub-scanning direction and complete the corresponding exposure, the latent image forming unit The unit 20 moves to a home position indicated by a solid line in FIG. 1, where development by the cyan developing device 61 is performed.

The cyan developing device 61 is retracted to a position distant from the photosensitive drum 21 during the reading and exposure as described above, but when the latent image forming unit 20 returns to the home position. Move to a position close to the photosensitive drum 21 at a predetermined timing, and
Is brought into contact with the photosensitive drum 21.

The cyan toner in the cyan developing device 61 is charged to a positive polarity by friction charging with a magnetic carrier or the like.
This positively charged toner is used as the developing roller 61A.
The photosensitive drum 21 is transported by the developing roller 61A to a contact position with the photosensitive drum 21, and the developing roller 61 is formed on the photosensitive drum 21 by the red light beam R.
A is attached to the electrostatic latent image formed so as to have a predetermined potential difference from A, and development is performed.

Here, the relationship between the spectral characteristics of the printing ink of the original image and the spectral characteristics of the semiconductor laser will be described with reference to FIG. FIG. 11 shows a case where the spectral characteristics of the red light beam R and the green light beam G are superimposed on the spectral characteristics of the basic colors in magenta (red), cyan (blue), black (black), and yellow (yellow) printing. FIG.
11A shows the case of magenta, FIG. 11B shows the case of cyan, FIG. 11C shows the case of black, and FIG. 11D shows the case of yellow. In each figure, the solid line indicates the spectral characteristic when each color is dark, and the broken line indicates the spectral characteristic when each color is light.

As can be seen from FIGS. 11A and 11B, when an image is read using the red light beam R,
It can be seen that in the portion where cyan ink is dominant, the amount of attenuation from the white level increases, and clear image information can be obtained. Therefore, when reading an image with the red light beam R, development is performed by the cyan developing device 61, so that a toner image of a corresponding color is formed on the photosensitive drum 21.

Similarly, when the image is read using the green light beam G, the attenuation from the white level is increased in the portion where the magenta ink is dominant, and clear image information can be obtained. You can see that. Therefore, when reading the image with the green light beam G, the toner image of the corresponding color is formed on the photosensitive drum 21 by performing development by the magenta developing unit 62.

Further, when an image is read using the blue light beam B, the amount of attenuation from the white level is increased in the portion where yellow ink is dominant, and clear image information can be obtained. I understand. Therefore, when reading the image with the blue light beam B, the toner is developed on the yellow developing unit 63, so that a toner image of a corresponding color is formed on the photosensitive drum 21.

In a portion where black ink is predominant, image information of the same level can be obtained with any of the light beams, so that development is performed by all the developing units and toners of all colors are superimposed. , A black image can be formed.

As described above, the reading of the red light beam R is performed by the development by the cyan developing unit 61, and a toner image is formed on the photosensitive drum 21 by the cyan toner. Then, in order to perform reading with the green light beam G, and corresponding exposure and development, the surface of the photosensitive drum 21 on which the toner image of the cyan toner is formed is recharged by the charger 23, and the above-described procedure is performed. While the latent image forming unit 20 is moved, reading with the green light beam G and exposure with the corresponding near-infrared light beam L are performed, and development with the magenta developing unit 62 is performed. Further, in order to perform reading with the blue light beam B and corresponding exposure and development, the surface of the photosensitive drum 21 on which the toner image of the cyan toner and the magenta toner is formed is recharged by the charger 23, and the above-described operation is performed. According to the procedure, reading with the blue light beam B and exposure with the corresponding near-infrared light beam L are performed, and development with the yellow developing device 63 is performed.

As a result, three color toner images of cyan, magenta, and yellow are formed on the photosensitive drum 21. The toner images are conveyed synchronously by the registration rollers 14. After being transferred onto the paper P by the transfer charger 71, it is separated from the photosensitive drum 21 by the separation charger 72, and is fixed by the heating roller 81 and the pressing roller 82 of the fixing unit 80. Accordingly, the three color toners formed on the sheet P are superimposed to form a full-color image, and the sheet P is discharged to the discharge tray 76 after fixing.

As described above, according to the laser copying apparatus of the present embodiment, the polarizing filter 7 is provided on the holding lid 4 to prevent the reading laser from being incident on the user's eyes and to accurately position the laser. Since the confirmed original is accurately read by the laser and recorded with the laser accurately, an excellent color copy image can be formed.

Further, since the read image can be easily digitally processed, for example, processing such as superimposition can be performed. The dichroic mirror 49 for separating the recording light beam and the reading light beam is provided by a dichroic mirror 49 shown in FIG.
2 shows a spectral reflection characteristic as shown in FIG. In FIG. 12, the horizontal axis represents wavelength and the vertical axis represents reflectance. The wavelength of the light beam emitted by the semiconductor laser for reading is λ1, the semiconductor laser for recording 3
Assuming that the wavelength of the light beam emitted by 9 is λ2 longer than λ1, the dichroic mirror 49 has a reflectance R1 for the wavelength λ1 and R2 smaller than R1 for the wavelength λ2. When the extinction ratio is used as an index indicating the wavelength separation characteristic of the dichroic mirror, in this case, R1 / R
2 is the extinction ratio. For example, when recording an image and reading an image at the same time, if the efficiency of separating the optical path by the dichroic mirror 49 is low, the reading light flux becomes stray light and acts on the photosensitive drum 21 as bias light, thereby causing a ground on the printed image. An adverse effect such as an adverse effect such as contamination, or a light beam corresponding to a signal modulating the recording semiconductor laser 39 is irradiated on the original 6 and is incident on the photodetector 54 as noise and the noise is mixed into the read image data. Effect.

Therefore, for example, if the light quantity for irradiating the original 6 for reading an image is 1 mW and the light quantity for irradiating the photosensitive drum 21 for recording is 100 μW, the light quantity at the time of recording ON / OFF The modulation factor, which is the ratio, is 10
Since about 0 times is required, the amount of light allowed as a bias to the photosensitive drum 21 is 1 μW, and the extinction ratio of the dichroic mirror 49 is preferably at least 1/1000.

The dichroic mirrors 43, 44 and 45 as the synthesizing means determine the efficiency from the light source, and the dichroic mirror 4 as the separating means.
An extinction ratio of about 9 is not required. Of course, the same parts having the same extinction ratio may be used to increase the efficiency. However, in terms of cost, the dichroic mirrors 43, 44, and 45 use a dielectric multilayer film as the dichroic mirror surface. It is more advantageous to use a half mirror surface which is a metal single layer film.

The dichroic mirrors 43, 44,
If the same dichroic mirror is used for the dichroic mirror 45 and the dichroic mirror 49, the
Since the wavelengths reflected by 3, 44 and 45 are also reflected by the dichroic mirror 49, the semiconductor lasers 27 and 45 are used for combining and separating optical paths for recording and reading.
When deciding the arrangement of 31, 35, 39 and the document table 3 and the photosensitive drum 21, when the dichroic mirrors 43, 44, and 45 are set to reflect the luminous flux used for image reading, the dichroic mirror is used. 49 is also set to reflect the light beam used for the reading.

The reading semiconductor laser is controlled so that only the image area is turned on for each scanning, so that the light beam emitted from the reading semiconductor laser does not enter the BD sensor 52. Therefore, when the accuracy of the BD signal can be maintained by using the dichroic mirror 49 for optical path separation, the light may be always turned on. If it is difficult to record an image read from the document 6 on the photosensitive drum 21 in the same scan due to a time required for signal processing or the like, image data corresponding to a read signal for one line is temporarily stored. It is also conceivable that the signal is stored in the line memory and output as a modulation signal to the recording semiconductor laser 39 in the next scan.

Further, by storing pixel data for one page of the document in the frame memory, a margin of processing time can be provided, so that when the next image of the document 6 is read, recording based on the image data stored in the frame memory is performed. The operations can be performed at the same time, and even when copying a large number of documents, the time is not doubled, and almost real-time copying can be realized.

As described in the above embodiment, since the original 6 is desirably read with visible light, the wavelength of the reading semiconductor laser is 400 nm to 70 nm.
The condition is that it is 0 nm. However, the original 6 written in a color including the wavelength to be used for reading cannot be read in principle, so it is desirable to read with light having a wavelength as short as possible. However, at present, a semiconductor laser oscillating at 600 nm or less is not practical. Therefore, for example, by using a nonlinear optical element such as SHG for a semiconductor laser or a solid-state laser light source such as YAG to shorten the wavelength, a practical short-wavelength laser can be realized.

Although only the formation of a color image has been described in the above embodiment, the present invention functions effectively also in the case of forming a monochrome image. In this case, a semiconductor laser for reading and a semiconductor laser for recording may be respectively provided, and reading and recording of the document may be performed as described above. Also, of course, a light source for reading,
The recording light source can be the same. At this time, the optical path may be switched between the reading time and the recording time by a movable mirror.

The scanning optical device of the present invention is applicable not only to a copying device but also to a scanner device dedicated to image reading. Further, the filter is not limited to a polarizing filter, and may be a color glass filter that does not transmit semiconductor laser light for reading. Furthermore, not limited to colored glass, a specific dye aqueous solution is absorbed by a gelatin film,
It is also possible to use a material in which both surfaces are bonded with a piece of glass sheet. Further, the filter may have a characteristic of absorbing light of a specific wavelength as well as a characteristic of reflecting light of a specific wavelength.

In the present embodiment, the photosensitive member is an OP.
Although the example using the C photoconductor drum has been described, the present invention is not limited to this. For example, aluminum is deposited as a conductive layer on an OPC belt photoconductor, a selenium belt photoconductor, or a polyester film. The photosensitive member and the developing roller may be moved in the opposite direction or in the same direction. Further, in addition to the photosensitive drum 21 as a photosensitive recording medium, a component that is sensitive to each of red, green, and blue wavelength light to harden or soften its mechanical strength, and a coloring material (dye precursor).
Self-coloring microcapsule paper that carries three types of microcapsules encapsulating the above and a developing material that reacts with three types of dye precursors to form cyan, magenta, and yellow, respectively, can also be employed. . In this case, as a recording light source, red, green, and blue semiconductor lasers are used to expose the microcapsule paper to form a latent image as an intensity distribution of the microcapsules. The microcapsule paper may be developed under pressure.
As is well known, pressure development means that capsules that are not cured or softened by exposure are broken under pressure, and the dye precursor of the inclusion is brought into contact with a color developer existing outside the capsule to cause a color development reaction. That is.

Further, in the above-described embodiment, the laser copying apparatus has been described. However, the present invention functions effectively also in a printer or a multifunction apparatus having a facsimile function.

[0081]

According to the first aspect of the present invention, the area corresponding to the area where the light beam from the light source is incident on the cover member for covering the document table is selectively used for the light beam other than the light beam from the light source. Because it was formed from a light selection member that transmits through
The document can be recognized from the outside of the lid member, and the displacement of the document during image reading can be eliminated. Further, since the light beam from the light source is blocked by the light selection member, it is possible to reliably prevent the light beam from entering the user's eyes, and to perform highly safe image reading.

According to the scanning optical device of the second aspect,
Since a polarization filter having a transmission axis perpendicular to the polarization direction of at least the light beam from the light source is used as the light selection member, the light beam can be blocked by the light selection member regardless of the wavelength of the light beam of the light source. Thus, it is possible to reliably prevent the luminous flux from entering the user's eyes, and to perform highly safe image reading. In addition, the original can be recognized from outside the lid member, and the positional deviation of the original during image reading can be eliminated.

According to the scanning optical device of the third aspect,
As the light selecting member, a reflection type filter that reflects at least the light beam from the light source is used, so that the light beam from the light source can be reliably reflected and blocked, and the light beam enters the user's eyes. Can be reliably prevented, and highly secure image reading can be performed. In addition, the original can be recognized from outside the lid member, and the positional deviation of the original during image reading can be eliminated.

According to the scanning optical device of the fourth aspect,
As the light selection member, an absorption filter that absorbs at least the light beam from the light source is used, so that the light beam from the light source can be reliably absorbed and blocked, so that the light beam enters the user's eyes. Can be reliably prevented, and highly secure image reading can be performed. In addition, the original can be recognized from outside the lid member, and the positional deviation of the original during image reading can be eliminated.

According to the scanning optical device of the fifth aspect,
Since a laser that emits a light beam with directivity is used as the light source, a high-precision image can be obtained while reliably preventing the risk that laser light is incident on the user's eyes by the light selection member of the lid member. And digital processing of the read information can be performed. In addition, the original can be recognized from outside the lid member, and the positional deviation of the original during image reading can be eliminated. Therefore, it is possible to perform high-quality image reading with high resolution and no displacement.

According to the scanning optical device of the sixth aspect,
Since a plurality of lasers having different oscillation wavelengths are used as the laser, the laser is formed in a plurality of colors while reliably preventing a risk that laser light is incident on a user's eyes by the light selecting member of the lid member. Image can be read with high accuracy. In addition, the original can be recognized from outside the lid member, and the positional deviation of the original during image reading can be eliminated. Therefore, it is possible to read a high-quality multi-color image having a high resolution and no displacement.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of a laser copying apparatus including a scanning optical device according to an embodiment of the present invention.

FIG. 2 is a plan view illustrating a schematic configuration of a laser scanner unit according to the embodiment of the present invention.

FIG. 3 is a side view illustrating a schematic configuration of a laser scanner unit according to the embodiment of the present invention.

FIG. 4 is a configuration diagram illustrating a state of detecting a light beam reflected by a document according to the embodiment of the present invention.

FIG. 5A is a plan view illustrating a state where a lid member including a light selection member according to an embodiment of the present invention is in a closed state, and FIG. 5B is a lid member including a light selection member according to the embodiment of the present invention. FIG. 4 is a plan view in a case where is in an open state.

FIG. 6 is a diagram illustrating a configuration of a light selection member according to the embodiment of the present invention.

FIG. 7 is a diagram illustrating transmission characteristics of a light selection member according to the embodiment of the present invention.

FIG. 8 is a block diagram illustrating a reading operation and a recording operation of the scanning optical device according to the embodiment of the present invention.

FIG. 9 is a diagram showing emission timing and intensity distribution of a red semiconductor laser which is a recording light source according to the embodiment of the present invention.

FIG. 10 is a timing chart showing a reading operation and a recording operation of the scanning optical device according to the embodiment of the present invention.

11A and 11B are diagrams illustrating a relationship between the spectral characteristics of the printing ink and the spectral characteristics of each semiconductor laser according to the embodiment of the present invention. FIG. 11A illustrates the case of magenta ink.
(B) is a diagram showing a case of cyan ink, (c) is a diagram showing a case of black ink, and (d) is a diagram showing a case of yellow ink.

FIG. 12 is a characteristic diagram illustrating a spectral reflection characteristic of the dichroic mirror according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Laser copy apparatus 3 ... Document stand 4 ... Holding lid 6 ... Document 7 ... Polarizing filter 10 ... Paper feeder 20 ... Latent image forming unit 21 ... Photoconductor drum 24 ... Laser scanner unit 27 ... Red semiconductor laser 31 ... Green semiconductor Laser 35 Blue semiconductor laser 39 Near infrared semiconductor laser 43, 44, 45 Dichroic mirror 47 Polygon mirror 48 Imaging lens 49 Dichroic mirror 50 Reflective mirror 60 Developing unit 70 Transfer unit 80 Fixing Department

Claims (6)

[Claims] A light source for irradiating light of a predetermined wavelength; a deflector for deflecting and scanning a light beam from the light source; and a light beam deflected and scanned by the deflector. Light-collecting means for condensing light and entering the document placed on the document table; light-receiving means for receiving scattered light from the document and reading image information on the document; and the document A light cover member for covering a document placing surface of the table, wherein at least a region corresponding to a light incident region of the light beam from the light source on the document table is a light selection member for selectively transmitting light other than the light beam from the light source; A scanning optical device, comprising: a lid member formed by: 2. The scanning optical device according to claim 1, wherein the light selecting member is a polarizing filter having a transmission axis perpendicular to at least a polarization direction of a light beam from the light source. 3. The scanning optical device according to claim 1, wherein the light selection member is a reflection filter that reflects at least a light beam from the light source. 4. The scanning optical device according to claim 1, wherein the light selection member is an absorption filter that absorbs at least a light beam from the light source. 5. The scanning optical device according to claim 1, wherein the light source is a laser that emits a light beam with directivity. 6. The scanning optical device according to claim 5, wherein the laser is a plurality of lasers having different oscillation wavelengths.