JPH10150529A - Scanning optical equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scanning optical equipment, in which a luminous flux emitted from a light source is prevented from being made incident directly onto the eyes of the user. SOLUTION: A laser emission port 8, made of a glass plate or the like and formed laterally long, is placed in the vicinity of an original platen 3 made of a glass plate or the like, and a photosensor 7 is provided to a rear side of a retainer cover 4, corresponding to a position of the laser emission port 8. Prior to the start of image reading, a laser scanner unit 24 emits a laser beam through the laser emission port 8 and an open/close state of the retainer cover 4 is discriminated according to the result of light received by the photosensor 7. When the retainer cover 4 is open as a result, the laser beam for the purpose of image reading is not irradiated.

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 flat original placing surface, and the read object is placed on the platen. A light beam from a light source is deflected and scanned by a polygon mirror to irradiate the light beam, and reflected light of the light beam from an object to be read is received by a light receiving unit such as a photodetector. The light beam is irradiated based on a light receiving signal from the light receiving unit. Image information corresponding to the read object that has been read.

The document placing surface is usually formed of a transparent material such as glass, and the irradiation of the light beam is performed over the entire area of the document placing surface. Outside the placement area, there is no obstacle to block the light beam,
The light beam is directly incident on the user's eyes.

In view of the above, 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 reading target is placed on the mounting surface, and reading is performed in a state where the reading target is pressed by the holding lid.

[0005]

However, in the conventional scanning optical device, when the irradiation of the light beam from the light source is started in a state where the holding lid is opened, the light beam directly enters the user's eyes. Due to the high linearity and high energy density of the laser light, there was a risk of damaging the eyes.

On the other hand, in the case of a reading object such as a thick book, the pressing lid cannot be completely closed due to the thickness of the reading object, and the reading object cannot be closed by the pressing lid. It was necessary to start reading while holding it down.

Therefore, the present invention solves the above problems,
It is an object of the present invention to provide a scanning optical device capable of preventing a light beam emitted from a light source from directly entering a user's eyes.

Further, the present invention solves the above-mentioned problems, and reliably executes reading even when the holding lid cannot be closed as in the case of reading an object to be read such as a thick book. It is an object of the present invention to provide a scanning optical device that can perform the scanning.

[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 and reading the image information on the document, a cover member for covering the document placing surface of the document table, and an open / closed state detecting means for detecting the open / closed state of the cover member, In order to obtain the scattered light from the document, the irradiation of the light beam to the document is controlled, and when the lid member is determined to be in the open state based on a signal from the open / closed state detecting means, the light from the light source is emitted. Light source set to not perform Characterized by comprising a control means.

According to the scanning optical device of the first aspect,
When an original is placed on the original platen and an instruction to start reading an image is issued, the light source control unit starts control to start irradiating the original with a light beam. When it is determined from the signal from the detecting means that the lid member is in the open state, the light from the light source is not emitted. Therefore, irradiation of the light beam is not performed with the lid member kept open, and the light beam is prevented from entering the user's eyes via the document table. On the other hand, when the lid member is determined to be in the closed state by the open / closed state detection unit, the light source control unit emits a light beam of a predetermined wavelength from the light source. As a result, the light beam is deflected and scanned by the deflector, condensed by the light condensing means, and made incident on the document placed on the document table. Then, the scattered light from the original is received by the light receiving means, and the image information is read.

According to a second aspect of the present invention, in the scanning optical device according to the first aspect, the open / closed state detecting means detects the open / closed state of the lid member by an operating member in contact with the lid member. Means for performing the operation.

According to the scanning optical device of the second aspect,
When the lid member is in contact with the operating member, it is detected that the lid member is in the closed state, and when the lid member is in a non-contact state with the operating member, the lid member is in the open state. Is detected. Then, based on the detection result, the irradiation of the reading light beam is controlled as described above.

According to a third aspect of the present invention, there is provided the scanning optical device according to the first aspect, wherein the lid member comprises:
A light detection unit as the open / closed state detection unit is provided on a side facing the document placing surface, and the light source control unit includes:
The apparatus is characterized in that irradiation of the light detecting means is performed before starting irradiation of the light beam to the document to obtain a signal from the light detecting means.

According to the scanning optical device of the third aspect,
If irradiation of the light detecting means provided on the lid member is performed before the irradiation of the light beam to the document is started, when the lid member is in the open state, the light detecting means is in the non-light receiving state. An output is obtained, and when the lid member is in the closed state, the output in the light receiving state is obtained from the light detecting means. Then, based on the signal output from the light detecting means, the irradiation of the light beam to the document is controlled as described above.

The scanning optical device according to a fourth aspect of the present invention is the scanning optical device according to the third aspect, further comprising means for detecting the open / closed state of the lid member by an operating member that contacts the lid member. Even when the light source control means determines that the lid member is in the closed state, the light source control means irradiates the light from the light source if it determines that the lid member is in the open state by a signal from the light detection means. Is set not to be performed.

According to the scanning optical device of the fourth aspect,
When the lid member is in contact with the operating member, it is detected that the lid member is in the closed state, and when the lid member is in a non-contact state with the operating member, the lid member is in the open state. Is detected. Then, based on the detection result, the irradiation of the reading light beam is controlled as described above,
When the lid member is in the open state, the light beam is not irradiated. On the other hand, when the lid member is in the closed state,
Further, the irradiation of the light beam is controlled based on the signal output from the light detecting means, and when the lid member is determined to be in the open state based on the signal output, the irradiation from the light source is not performed.

A scanning optical device according to a fifth aspect is the scanning optical device according to the third or fourth aspect,
The light source control unit further includes a selection unit that selects whether to stop or continue the irradiation of the light beam to the document, wherein the light source control unit determines that the lid member is in the open state based on a signal from the light detection unit. Is set so as to perform the irradiation when the continuation of the irradiation is selected.

According to the scanning optical device of the fifth aspect,
If irradiation of the light detecting means provided on the lid member is performed before the irradiation of the light beam to the document is started, when the lid member is in the open state, the light detecting means is in the non-light receiving state. An output is obtained, and control is performed to stop the irradiation of the light beam to the document.
Then, when the stop of the irradiation is selected by the selecting unit, the irradiation is stopped as it is, and when the continuation of the irradiation is selected by the selecting unit, the irradiation is performed.

According to a sixth aspect of the present invention, in the scanning optical device according to any one of the third to fifth aspects, the light source control means controls the luminous flux only at a predetermined light detecting means position. Is set to be irradiated.

According to the scanning optical device of the sixth aspect,
Irradiation of the light beam to the light detecting means is performed only to a predetermined light detecting means position, so that the light beam is surely prevented from entering the user's eyes.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. 1 to 9 of the accompanying drawings. 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.

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), and a fluorescent lamp, 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 a scorotron-type charger for positive charging, for example, which generates corona discharge from a charging wire made of 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.

A laser scanner unit 24 is provided above each device such as the photosensitive drum 21 described above. As shown in FIG. 3, a laser scanner unit 24 includes a semiconductor laser 33 as a light source used for image recording and a collimating lens 34 for making a light beam emitted from the semiconductor laser 33 substantially parallel in a scanner frame 31. A laser unit 32 is integrated with a stop 35 for reducing the spot diameter of the parallel light beam to a predetermined size. In addition, the semiconductor laser 33
A cylindrical lens 36 having an effect of converging in only one direction is provided on the optical path of the emitted light beam. At the focal position of the cylindrical lens 36, a regular hexagonal polygon mirror 37 as a deflector is provided so as to be rotatable at a constant speed around the center of the regular hexagon, and the light is reflected by the reflection surface. The light beam thus scanned is scanned at a constant angular velocity in the main scanning direction.

On the optical path of the light beam reflected by the polygon mirror 37, a condensing lens 40 as a light condensing means for condensing the light beam on the photosensitive drum 21 is provided. The condensing lens 40 is composed of two lenses, condenses the light beam deflected and scanned so as to irradiate it on the photosensitive drum 21 with a minute spot, and converts the light beam deflected and scanned by the polygon mirror 37 at a constant angular velocity. There is a fθ specification for converting to linear scanning at a constant linear velocity on the drum 21.

On the other hand, another part of the scanner frame 31 includes a semiconductor laser 42 as a light source used for image reading, a collimating lens 43 for making a light beam emitted from the semiconductor laser 42 substantially parallel, A stop 44 for reducing the spot diameter of the changed light beam to a predetermined size.
Is attached. A dichroic mirror 45 as an optical path synthesizing means is disposed at a point where the light beam emitted by the reading semiconductor laser 42 and the light beam emitted by the recording semiconductor laser 33 intersect.

The dichroic mirror 45 has the property of transmitting the light beam of the wavelength of the semiconductor laser 33 and reflecting the light beam of the wavelength of the semiconductor laser 42. In this embodiment, the luminous flux of the semiconductor laser 33 and the luminous flux of the semiconductor laser 42 have an angle of 90 °.
Is incident on the dichroic mirror 45 at an incident angle of 45 °, and the luminous fluxes of the two lasers after passing through the dichroic mirror 45 are combined and travel on the same optical path.

The condenser lens 40 and the photosensitive drum 21
As shown in FIGS. 3 and 4, a dichroic mirror 46 as an optical path separating means having substantially the same characteristics as the dichroic mirror 45 described above, and a semiconductor laser 33 transmitted through the dichroic mirror 46 emits light. A reflection mirror 47 is provided to reflect the light flux toward the photosensitive drum 21 (below the laser scanner unit 24 in FIG. 1) and guide the light flux to the photosensitive drum 21.

A BD mirror 51 for reflecting a recording light beam emitted from the semiconductor laser 33 and a BD mirror 51 are provided at positions in the scanner frame 31 corresponding to positions outside the irradiation range of the photosensitive drum 21. A BD sensor 52 is provided for detecting the reflected light flux to generate a horizontal synchronization signal.

Further, as shown in FIGS. 1 and 4, a document table 3 made of glass on which a document 6 on which an image is recorded is placed above the laser scanner unit 24. At a position facing the document 6 with the document table 3 interposed therebetween, a light detecting lens 38 for detecting a light beam scattered and reflected by the document 6 and a light receiving means including a photodiode as a well-known photoelectric conversion element are provided. Photodetector 3
Reference numerals 9 are arranged at regular intervals in three in a direction parallel to the scanning direction of the light beam (see FIG. 5). The number of the photodetectors 39 is not limited to three, but may be more (for example, seven). If you do this,
Irregularities in the sensitivity of the photodetector 39 can be reduced. That is, the position of the light beam irradiated on the original 6 is determined by the light detector 39.
When the position of the irradiation light beam is far from the front, the amount of received light is small. For this reason, in order to compensate for the decrease in sensitivity of the detection boundary region of each photodetector, the change in detection sensitivity for each position of the irradiation light beam can be kept within an allowable value by taking the sum of the light reception amounts of the respective detectors 39. it can. The presence / absence of a pixel at the irradiation position can be determined by comparing the total value of the received light amount at each irradiation position with a predetermined threshold value.

Further, the position of the document table 3, that is, the mounting surface of the document 6, coincides with the focal position of the condenser lens 40 and is optically conjugate with the position of the photosensitive drum 21. . Accordingly, the spot diameter of the light beam that scans on the photosensitive drum 21 and the spot diameter that scans on the original 6 become equal, and the accuracy when recording the original and the accuracy when reading the image become equal. As a result, the image on the document 6 can be faithfully reproduced on the photosensitive drum 21. That is, manuscript 6
Is a light beam emitted from the semiconductor laser 42 and reflected by the dichroic mirror 46,
Light beam emitted from semiconductor laser 33 and semiconductor laser 4
The light beams emitted from 2 are combined by the dichroic mirror 45 and travel on the same optical path, are separated by the dichroic mirror 46, and only the light beam emitted from the semiconductor laser 33 irradiates the photosensitive drum 21. Only the light beam emitted from the semiconductor laser 42 irradiates the document 6.

The latent image forming unit 20 having the above-described structure 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). It is supposed to do.
Specifically, the position of the latent image forming unit 20 indicated by a solid line in FIG. 1 is a home position. After performing a pre-scan described later at this home position, the latent image forming unit 20 reads the original 6 on the original table 3. The document 6 in the main scanning direction,
The exposure of the photosensitive drum 21 corresponding to the reading 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 shown by an arrow in FIG. 1 and moves to a position shown by a two-dot chain line in FIG. Thus, reading of the document 6 in the sub-scanning direction and exposure of the photosensitive drum 21 are performed. 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 developing by the developing unit 60 is performed.

As described above, during the copying operation,
Since the light beam for reading is emitted through the platen 3,
It is necessary to cover the original placing surface of the original platen 3 so that these light beams do not enter the eyes of the user. In the case of a thick book or the like, in order to maintain the flatness of the original surface, A holding cover 4 that covers the document table 3 is provided to be freely opened and closed by a hinge or the like. When the cover 4 covers the document table 3 as shown in FIG. 1, it has a function of blocking the light beam and a function of pressing the book or the like from above.

However, depending on the user, there is a case where the copying operation is attempted to be started without closing the holding cover 4, and there is a possibility that the light beam enters the eyes of the user. In particular, when a laser is used, straightness and energy density are higher than those of a conventional halogen lamp or the like,
Since the risk of entering the eye increases, it is necessary to ensure safety.

Therefore, in the present embodiment, as shown in FIG. 2A, an opening / closing state detecting means and an optical sensor 7 as light detecting means provided on the side of the holding cover 4 opposite to the original placing surface are provided. As shown in FIG. 6, a signal from the optical sensor 7 is read by a timing control circuit 82 as light source control means, and the irradiation of the reading semiconductor laser 42 is controlled.

The optical sensor 7 is a sensor composed of a photodiode or the like similar to the photodetector 39 described above, and as shown in FIG. That is, it is provided on the side opposite to the document placing surface. The position where the optical sensor 7 is provided is set outside the document placing area on the document table 3 and is a plan view of the laser copying apparatus 1 in a state where the holding cover 4 is removed.
As shown in (B), it is set at a position where the light beam emitted from the laser emission window 8 can be detected. The laser emission window 8 is formed of glass or the like, and is disposed at a portion closer to the end of the main body case 2 than the document table 3. Further, the optical sensor 7 is not provided in a plural number in the longitudinal direction of the laser emission window 8, but is provided at a predetermined position in a region corresponding to the laser emission window 8 as shown in FIG. ing.

Before the image reading is started, the latent image scanner unit 20 is located at a position where the laser beam can be emitted to the laser emission window 8 as shown in FIG. 2C. Before starting the image reading, a pre-scan for checking the open / closed state of the holding lid 4 is performed. This pre-scan is performed only for the arrangement position of the optical sensor 7 determined by the elapsed time after the signal output from the BD sensor 52.

However, when a slightly thick book or the like is placed on the document table 3, the holding cover 4 is opened halfway, and there is a delay between the time when the signal of the BD sensor 52 is output and the time when the output of the optical sensor 7 is obtained. May occur. Therefore, by providing a certain width to the output detection start timing of the optical sensor 7 after the output from the BD sensor 52 and the output detection period of the optical sensor 7, for example, by providing a width of ± 10 μsec or the like,
The open / closed state of the holding lid according to the actual use state can be detected.

The detection result of the optical sensor 7 at the time of the pre-scan is the timing control circuit 8 shown in FIG.
2, and the timing control circuit 82 controls the pressing lid 4
Is determined.

It should be noted that the prescan should be performed once or at most.
Just go around. This is because it is dangerous to emit lasers unnecessarily. Next, the configuration of the developing unit 60 that is driven after the reading of an image is performed after the detection of the open / closed state of the holding lid 4 as described above and the corresponding exposure is performed will be described. As shown in FIG. 1, the developing unit 60 is disposed below the photosensitive drum 21 when the latent image forming unit 20 is at the home position, and includes a toner box 61 containing toner and a developing roller 62. Have.
The toner box 61 stores positively charged toner having electrical insulation, and supplies the toner to the developing roller 62 via a toner supply port formed in the toner box 61.

The developing roller 62 is a conductive rigid roller made of silicon rubber, urethane rubber, or the like, which forms a nip at the developing position by contacting the photosensitive drum 21. In the present embodiment, for example, a photosensitive drum 21 having an organic photosensitive layer containing a positively charged toner and a positively charged polycarbonate as main components is used.
, Urethane rubber is used as the material of the developing roller 62.

The developing roller 62 is connected to a power supply (not shown) for supplying a developing voltage.
The developing voltage is controlled by a controller (not shown) so as to be supplied when the developing roller 62 operates.

The toner in the present embodiment is a positively charged toner, and is, for example, a non-magnetic one-component toner composed of a pulverized toner or a polymerized toner made of styrene acrylic having a nearly spherical shape, and is composed of a raw toner and a raw toner. And silica as an external additive (fluidity-imparting agent) added to the composition. As a result, most of the toner is rubbed by the developing roller 62, the photosensitive drum 21 and the like, and is charged to a positive (positive) polarity. Then, the toner is charged to a negative (negative) polarity to be a reverse polarity toner, albeit in a small amount.

The transfer charger 7 is located downstream of the contact portion between the developing roller 62 and the photosensitive drum 21 in the moving direction of the photosensitive drum 21 and below the photosensitive drum 21.
1 is provided. The transfer charger 71 is provided below the photoconductor drum 21 so as to face the photoconductor drum 21, and similarly to the exposure charger 23, a corona discharge is performed from a charging wire made of, for example, tungsten or the like. This is a scorotron-type charger for positive charging that generates.

A fixing unit 75 is provided on the downstream side in the transport direction of the paper P from the opposing portion of the transfer charger 71 and the photosensitive drum 21. The fixing unit 75 includes a heating roller 76 having a built-in halogen lamp and a pressing roller 77. The fixing unit 75 fixes the toner image transferred onto the upper surface of the sheet P by heating and pressing the toner image onto the sheet P. ing.

Further, the paper P
On the downstream side in the transport direction, a pair of transport rollers 78 for transporting the paper and a paper discharge tray 90 are provided, and the paper P discharged from the fixing unit 75 is guided to the outside of the copying apparatus and placed thereon. It has become.

Next, the operation of the laser copying apparatus 1 configured as described above will be described with reference to FIGS. In particular, the pre-scan operation will be described with reference to the flowchart of FIG.

First, the document 6 is placed on the document table 3, the holding cover 4 is closed, and a 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, the prescan operation is started, and a reading light beam is emitted from the reading semiconductor laser 42 with directivity. This light beam passes through the collimator lens 43 and becomes substantially parallel light, and becomes a light beam of a desired size by the stop 44. The dichroic mirror 45
Incident on. Thereafter, the reading light beam is reflected and deflected by the polygon mirror 37, enters the dichroic mirror 46, is reflected by the dichroic mirror 46, and irradiates the laser emission window 8 (step S1 in FIG. 7).
At this time, if the holding lid 4 is in the open state, the laser emission window 8 is opened.
Is not incident on the optical sensor 7 provided on the holding lid 4, the output of the optical sensor 7 read by the timing control circuit 82 is different from the output when the optical beam does not enter. Become. Therefore, when the timing control circuit 82 determines whether or not light reception by the optical sensor 7 has been performed (step S2), it is recognized that light reception is not performed (step S2; YES). as a result,
It is determined that the holding lid 4 is in the open state, and a warning is issued to the user (step S3). As a method of this notification, there is a method of turning on a warning LED, sounding a buzzer for warning, or displaying a message on a display panel on the operation unit.

Next, it is determined whether or not to execute further scanning even in the state where the warning is notified to the user as described above (step S4). This takes into consideration the case where the cover 4 cannot be closed, as in the case of reading a thick book or the like, and is a step of waiting for a user's selection. Specifically, if a clear key or the like (not shown) serving as a selection unit is pressed in a state in which the warning is notified, it is determined that the scanning is stopped (step S4; N).
O). Alternatively, if the start key (not shown) as the selection means is not pressed again within a predetermined period after the warning is notified, it may be determined that the scanning is to be stopped.

As described above, since the scanning is not started when the holding lid 4 is in the open state, it is possible to reliably prevent the reading laser from entering the user's eyes.
On the other hand, when the start key is pressed again after closing the holding lid 4 in response to the warning, or when the holding lid 4 is closed from the beginning, the light beam for reading is provided on the holding lid 4. Since the light is incident on the optical sensor 7, the output of the optical sensor 7 read by the timing control circuit 82 is an output when a light beam is incident, and it is recognized that the light sensor has received light (step S2; YE
S).

Then, the latent image forming unit 20 is
The original is moved to a position where the upper document 6 can be irradiated with the light beam for reading, and a normal scan is executed (step S4).
The subsequent copy operation is continued. Specifically, a reading light beam is emitted from the reading semiconductor laser 42 with directivity, passes through the collimating lens 43, becomes substantially parallel light, and becomes a light beam of a desired size by the diaphragm 44.
The light enters the dichroic mirror 45. Thereafter, the reading light beam is reflected and deflected by the polygon mirror 37 and enters the dichroic mirror 46, where
The light is reflected at 6 and is irradiated toward the original 6 on the original table 3.

The light beam scans the original 54 one-dimensionally as the polygon mirror 37 rotates, and the latent image forming unit 20 itself is driven by a driving means (not shown) in the sub-scanning direction (in the direction of the arrow shown in FIG. 1). 2) at a predetermined timing, the reading light beam irradiates the original 6 two-dimensionally as raster scanning. As means for controlling the movement of the latent image forming unit 20 in the sub-scanning direction, the above-described timing control circuit 82 may be used, or another control means such as a CPU may be provided.

The luminous flux applied to the original 6 is scattered and reflected by the original 6, and is condensed on a photodetector 39 by a light detection lens 38. Here, when the image formed on the original 6 is written with ink or dye, it is recognized as black by human eyes, but when irradiated with infrared light, the image portion is also reflected and becomes white. May be detected as That is, the original 6 is desirably read by visible light, and therefore, the wavelength of the semiconductor laser 42 as a reading light source is required to be 400 nm to 700 nm. On the other hand, the semiconductor laser 33 serving as the recording light source does not need to be visible light, and is 780 n which is near infrared light in view of the spectral sensitivity and cost of the general photosensitive drum 21.
It is preferable to use a wavelength of m.

FIG. 5 is a plan view showing the positional relationship between the light detection lens 38 and the light detector 39 arranged in a direction parallel to the scanning direction. Three light detection lenses 38 and three light detectors 39 are arranged so as to equally divide the image reading width of the document 6. The original 6 and the photodetector 39 are
The optical detection lens 38 has an optically conjugate relationship with each other. The imaging magnification of the light detection lens 38 is determined according to the size of the photodetector 39.
Scan the width of the document of the size in the width direction (210 mm),
When the light beam reflected from the document 6 is detected by the three light detectors 39, the width detected by one light detector 39 is 70 mm. Therefore, if the width of one light detector 39 is 5 mm, The imaging magnification may be 1/14. The signals of the photodetectors 39 arranged in this manner are added together, and by detecting a light flux whose amount of light reflected according to 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.

In this embodiment, the image signal corresponding to the image read in this way is transmitted to the recording semiconductor laser 33.
As shown in FIG. 6, an output signal from the photodetector 39 is directly input to the modulation circuit 80 for use as a modulation signal.

The reading semiconductor laser 42 is
Although the CW is turned on by 1, the reading start positions need to be aligned in order to read an image area to be scanned every scan. When scanning the photosensitive drum 20 by driving the recording semiconductor laser 33, 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 is performed by inputting a signal obtained from the BD sensor 52 to the timing control circuit 82 as a light source control unit, and aligning signal generation timings of the drive circuit 81 and the modulation circuit 80. realizable.

Specifically, as shown in FIG. 3, of the light beams deflected and scanned according to the rotation of the polygon mirror 37,
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.

The light beam emitted with directivity from the semiconductor laser 33 according to the signal modulated by the modulation circuit 80 as described above passes through the collimator lens 34 and becomes substantially parallel light. The luminous flux converged to a desired size by the diaphragm 35 passes through the dichroic mirror 45, passes through a cylindrical lens 36 having a convergence effect in only one direction, and enters a polygon mirror 37 as a deflector as a linear image. I do. Further, the light beam is reflected and deflected toward the condenser lens 40 by the polygon mirror 37, passes through the dichroic mirror 46, is reflected downward by the reflection mirror 47 in FIGS. 1 and 4, and irradiates the surface of the photosensitive drum 21. I do. Then, the irradiated light beam exposes the photosensitive drum 21 rotating around the center.

FIG. 8 is a timing chart showing the operation timing of the reading semiconductor laser 42 and the recording semiconductor laser 33. The recording semiconductor laser 33 is B
The light beam is turned at prior time T _p for entering the D sensor 52. At this time, the reading semiconductor laser 4
2 is turned off to increase the timing accuracy. With the rotation of the polygon mirror 37, the light beam from the recording semiconductor laser 33 enters the BD sensor 52 and
When the signal is detected, the reference time T _{0 of} one scan is set and the recording semiconductor laser 33 is turned off once. However, after turning off the light, the reading semiconductor laser 42 is turned on at a time T _rs after a lapse of a fixed time, Similarly, at a time T _s after a lapse of a predetermined time, the recording semiconductor laser 33 is modulated and driven in accordance with the image signal detected by the photodetector 39. Here, the relationship between the time T _rs and T _s is determined by inputting the read signal obtained by the photodetector 39 to the modulation circuit 90 and inputting the read signal to the recording semiconductor laser 3.
This is the time including the delay until the modulation of No. 3. Then, the image area (for example, 210 mm, which is the width in the A4 lateral direction)
At time T _re and T _e corresponding to the scanning of the reading semiconductor laser 42 is turned off. Then, this operation is repeated every scanning.

As described above, the laser scanner unit 24
Of the original in the main scanning direction and the photosensitive drum 2
As the latent image forming unit 20 moves in the sub-scanning direction while performing the exposure of 1, the reading of the document in the sub-scanning direction is performed, and with the movement of the latent image forming unit 20 in the sub-scanning direction. As the photosensitive drum 21 rotates clockwise, exposure in the sub-scanning direction is performed.

The exposure of the photosensitive drum 21 is performed by irradiating the recording light beam as described above. Prior to this irradiation, the residual charge on the photosensitive drum 21 is discharged by the discharge lamp 22 at a predetermined timing before the irradiation. After the cleaning, the surface of the photosensitive drum 21 is uniformly charged to a predetermined potential by the charger 23 for positive charging. In this state, the recording light beam irradiated as described above is irradiated on the photosensitive drum 21, and an electrostatic latent image corresponding to the read image is formed on the photosensitive drum 21.

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 in the sub-scanning direction and complete the corresponding exposure, the latent image forming unit 20 moves to the position shown in FIG. Then, the developing unit 60 moves to a home position indicated by a solid line, where development is performed.

Most of the particles of the toner in the toner box 61 are charged to a positive polarity by the rubbing with the developing roller 62 and the friction of the layer thickness regulating plate (not shown) against the developing roller 62. The positively charged toner is rubbed and charged by the developing roller 62 and the photosensitive drum 21, and is formed on the photosensitive drum 21 by a laser beam so as to have a predetermined potential difference with the developing roller 62. Attachment to the electrostatic latent image causes development.

Then, the paper P is fed by the registration roller 14 at the same timing as the developing process, and the image developed with the toner is transferred onto the fed paper P by the transfer charger 71. After being separated from the photosensitive drum 21 by the separation charger 72, the fixing unit 75
And is discharged to the paper discharge tray 90.

As described above, according to the laser copying apparatus of this embodiment, when the holding lid 4 is not closed, the laser beam for reading is not irradiated, so that the laser beam enters the eyes of the user. Danger can be prevented.

Also, the laser irradiation in the pre-scanning is controlled so that the laser is emitted only at the scanning position incident on the optical sensor 7, so that safety can be ensured.

When the cover 4 cannot be closed as in the case of a thick book or the like, reading can be performed by the user's selection, so that a user-friendly laser copying apparatus can be provided. .

Further, since the read image can be easily digitally processed, a process such as superimpose can be performed by storing the read image information in the memory 83 shown in FIG. 6, for example.

The dichroic mirror 46 for separating the recording light beam and the reading light beam has a spectral reflection characteristic as shown in FIG. FIG. 6 shows the wavelength on the horizontal axis and the reflectance on the vertical axis. Assuming that the wavelength of the light beam emitted by the reading semiconductor laser is λ1 and the wavelength of the light beam emitted by the recording semiconductor laser 39 is λ2 longer than λ1, the dichroic mirror 49 has a reflectance R1 for the wavelength λ1, For the wavelength λ2, R2 is smaller than R1. When the extinction ratio is used as an index indicating the wavelength separation characteristics of the dichroic mirror, R1 / R2 is the extinction ratio in this case. 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 flux corresponding to a signal for modulating the recording semiconductor laser 39 is irradiated on the original 6 and is incident on the photodetector 39 as noise and the noise is mixed into the read image data. Effect.

Thus, for example, if the light amount for irradiating the original 6 for reading an image is 1 mW and the light amount for irradiating the photosensitive drum 21 for recording is 100 μW, the light amount 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 mirror 45 as the synthesizing means determines the efficiency from the light source, and does not require the extinction ratio of the dichroic mirror 46 as the separating means. Of course, it is conceivable to use the same parts having the same extinction ratio in order to increase the efficiency. However, in terms of cost, the dichroic mirror 45 has
It is more advantageous to use a half mirror surface which is a metal single layer film than to use a dielectric multilayer film as a dichroic mirror surface.

The dichroic mirrors 45 and 46
If the same dichroic mirror is used, the wavelength reflected by the dichroic mirror 45 is naturally also reflected by the dichroic mirror 46. Therefore, the semiconductor laser 33 is used for synthesizing and separating the optical paths for recording and reading. , 42 and the arrangement of the document table 3 and the photosensitive drum 21, when the light flux used for reading the image is set to be reflected by the dichroic mirror 45, the dichroic mirror 46 is also used for reading the image. The setting is to reflect the light beam.

The reading semiconductor laser is controlled so that only the image area is turned on for each scan, 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 46 for the 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. Therefore, 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 semiconductor laser for reading 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.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, as shown in FIG. 10, an open / close switch 15 is provided as a means for switching the ON / OFF state by contact with the holding lid 4, and is used together with the optical sensor 7. Therefore, as shown in FIG. 11, a signal from the open / close switch 15 is read by a timing control circuit 82 as a light source control means, and the irradiation of the reading semiconductor laser 42 is controlled.

As shown in FIG. 10, the opening / closing switch 15 is provided with an operating member 16 provided to be movable up and down by contacting the holding cover 4, and an opening / closing switch 15 capable of contacting the operating member 16 and having a center. ON / O depending on the pressing state of the pressing member 17 provided rotatably around the axis and the pressing member 17
And a push switch 18 for switching the state of the flip-flop. The operating member 16 is urged upward from an urging member such as a spring (not shown), and the pressing member 17 is also urged in a direction to press the push switch 18 from an urging member such as a spring not shown. When the cover 4 is in the open state, the push switch 18 is pressed by the pressing member 17 to be in the ON state. On the other hand, when the holding lid 4 is closed, the operating member 16 moves downward and rotates the pressing member 17, so that the push switch 18 is not pressed by the pressing member 17, and thus is in the OFF state. Then, ON / OFF of the push switch 18
The state is transmitted to the timing control circuit 82 shown in FIG.
The timing control circuit 82 determines whether the cover 4 is open or closed.

Next, the operation of this embodiment will be described. Note that the processing after the processing described below is the same as in the first embodiment, and a description thereof will not be repeated.
In FIG. 12, the same steps as those in the first embodiment are denoted by the same step numbers.

First, the original 6 is placed on the original platen 3, the holding cover 4 is closed, and a copy start key is pressed on an operation panel (not shown) provided on the upper surface of the laser copying apparatus 1 to perform prescan. Done. However, in the present embodiment, before the light beam is irradiated from the reading semiconductor laser 42 as in the first embodiment, the open / close switch 1 is turned on.
5 is read by the timing control circuit 82 to determine the open / closed state of the holding lid 4 (step S10). Here, when the presser cover 4 is open, the push switch 18 is turned on, so that the output of the open / close switch 15 becomes, for example, H level. Therefore,
The timing control circuit 82 sets the output of the open / close switch 15 to H
If the level is recognized (step S10; Y
ES), a warning is notified to the user (step S3).

On the other hand, when the holding lid 4 is closed, the push switch 18 is turned off, so that the output of the open / close switch 15 becomes, for example, L level. However, the output of the open / close switch 15 becomes L level not only when the holding lid 4 is closed, but also when the user directly presses the operating member 16 with a finger, or when the push switch 18 or the like breaks down. May be considered.
Therefore, in the present embodiment, the open / closed state of the holding lid 4 is also detected by the optical sensor 7.
First, the light beam for reading is irradiated from the semiconductor laser 42 to the laser emission window 8 in the same manner as in the first embodiment, and then the light is received by the optical sensor 7 in the timing control circuit 82 in the same manner as in the first embodiment. Is determined (step S2), and when it is recognized that no light is received (step S2; YES), a warning is issued to the user (step S3), and further scanning is performed. It is determined whether or not to perform (step S4). Then, if the clear key or the like is pressed in a state where the warning is notified, it is determined that the scanning is stopped (Step S4; N).
O). Alternatively, if the start key is not pressed again within a predetermined period after the warning is issued, it may be determined that the scanning is to be stopped.

As described above, according to the present embodiment, the open / close switch 15 and the optical sensor 7 are used together to determine the open / closed state of the press cover 4, so that the press cover 4 is opened by the open / close switch 15. When it is detected that the user is performing the operation, a warning can be given to the user without irradiating the laser beam. Further, even when the open / close switch 15 fails or when the user directly presses the operating member with his / her finger, the detection by the optical sensor 7 is performed, so that it is possible to reliably prevent the laser beam from entering the user's eyes. Can be.

In the present embodiment or the first embodiment, the pre-scan processing is terminated when the scanning is stopped after the warning is issued to the user. The present invention is not limited to this. After the scan continuation determination process (step S4) shown in FIGS. 7 and 12, the light reception determination process of the optical sensor 7 is provided again, and it is confirmed that the holding lid 4 is in the closed state. The scan may be started later, or the scan may be started immediately after the confirmation.

Further, the laser emission window is not limited to the horizontally long one as described in the above embodiment, and it may be configured such that only the optical sensor portion is opened. Instead of providing the laser exit window separately from the original table, a part of the original table may be used as the laser exit window. However,
In this case, it is necessary to devise a method such as displaying the document placement position on a document table so that the user does not place the document on that portion.

In the above-described embodiment, only the formation of a monochrome image has been described. However, the present invention functions effectively when a color image is formed. In this case, three-color lasers of R, G, and B may be provided as semiconductor lasers for reading, and the document may be read by reciprocating the latent image forming unit 20 three to four times. Then, a single color laser may be provided as a recording laser, and development units each provided with cyan, magenta, yellow, or black toner may be arranged in parallel to form a color image. The recording lasers R, G,
A laser of three colors B may be provided.

Further, the scanning optical device of the present invention is applicable not only to a copying device but also to an image reading-only scanner device. In the present embodiment, the photoconductor is 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. Furthermore, in the above-described embodiment, the laser copying apparatus has been described. However, the present invention functions effectively also in a multifunction apparatus having a printer or a facsimile function.

[0092]

According to the first aspect of the present invention, when the lid member is determined to be in the open state by the signal from the open / close state detecting means before the irradiation of the light beam to the original is started, Since the irradiation is not performed, it is possible to surely prevent the light flux from entering the user's eyes. Therefore, it is possible to perform highly accurate image reading while preventing the risk of damaging the eyes.

According to the scanning optical device of the second aspect,
As the opening / closing state detecting means, a means for detecting the opening / closing state of the lid member is provided by abutting the lid member and the operating member, so that the light beam enters the user's eyes by a simple mechanism. Can be reliably prevented.

According to the scanning optical device of the third aspect,
As the opening / closing state detecting means, a light detecting means provided on the lid member is provided, and the irradiation of the light beam to the document is controlled according to the output from the light detecting means, so that the opening / closing state of the lid member is further improved. Accurate detection is possible, and it is possible to reliably prevent the light flux from entering the user's eyes. Therefore, it is possible to perform highly accurate image reading while preventing the risk of damaging the eyes.

According to the scanning optical device of the fourth aspect,
Means for detecting the open / closed state of the lid member by an operating member abutting on the lid member, and when the lid member is determined to be in the closed state by the means, the lid is detected by a signal from the light detection means. When it is determined that the member is in the open state, the irradiation from the light source is not performed. Therefore, when the operation member is erroneously operated or when the means for detecting the open / closed state of the lid member by the operation member fails. Also,
The open / closed state of the lid member can be detected more accurately.

According to the scanning optical device of the fifth aspect,
Even in the case where the irradiation of the light beam to the document is to be stopped based on the output of the light detecting means, the stopping or continuation of the irradiation is determined by the selecting means, so that the open / close state of the lid member can be detected more accurately. Thus, it is possible to reliably prevent the light beam from entering the eyes, and to surely read an image when a thick book or the like is placed on the document table.

According to the scanning optical device of the sixth aspect,
Since the irradiation of the light beam to the light detecting means is performed only to the predetermined light detecting means position, the opening / closing state of the cover member is more accurately detected to ensure that the light beam enters the eyes. In addition to this, it is possible to reliably prevent the light flux from entering the user's eyes even when detecting the open / closed state of the lid member.

[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 a first embodiment of the present invention.

2A is a plan view of a lid member of the laser copying apparatus according to the first embodiment of the present invention, FIG. 2B is a plan view of the laser copying apparatus with the lid member removed, and FIG.
FIG. 2 is a side sectional view of the laser copying apparatus.

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

FIG. 4 is a side view showing a schematic configuration of the laser scanner unit according to the first embodiment of the present invention.

FIG. 5 is a configuration diagram illustrating a state of detecting a light beam reflected by a document according to the first embodiment of the present invention.

FIG. 6 is a block diagram for explaining a reading operation and a recording operation of the scanning optical device according to the first embodiment of the present invention.

FIG. 7 is a flowchart illustrating a pre-scan process according to the first embodiment of the present invention.

FIG. 8 is a timing chart showing a reading operation and a recording operation of the laser scanner unit according to the first embodiment of the present invention.

FIG. 9 is a characteristic diagram illustrating a spectral reflection characteristic of the dichroic mirror according to the first embodiment of the present invention.

FIG. 10 is a side view of a laser copying apparatus including an open / closed state detecting unit according to a second embodiment of the present invention.

FIG. 11 is a block diagram illustrating a connection state of an open / closed state detection unit according to the second embodiment of the present invention.

FIG. 12 is a flowchart illustrating a pre-scan process according to the second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Laser copy apparatus 3 ... Document stand 4 ... Holding lid 6 ... Document 7 ... Optical sensor 15 ... Open / close switch 16 ... Activation member 20 ... Latent image forming unit 21 ... Photoconductor drum 24 ... Laser scanner unit 33 ... Recording semiconductor laser 37 ... Polygon mirror 38 ... Light detection lens 39 ... Photodetector 40 ... Condenser lens 42 ... Reading semiconductor laser 45,46 ... Dichroic mirror 82 ... Timing control circuit

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 cover member that covers the document mounting surface of the table, an open / closed state detection unit that detects an open / closed state of the cover member, and controls irradiation of the light flux on the document to obtain scattered light from the document, Light source control means set so as not to irradiate the light source when the lid member is determined to be in an open state based on a signal from the open / closed state detection means. apparatus. 2. The scanning optical apparatus according to claim 1, further comprising means for detecting the open / closed state of the lid member by an operating member that contacts the lid member, as the open / closed state detection unit. 3. The lid member includes a light detection unit as the open / closed state detection unit on a side facing the document placing surface, and the light source control unit starts irradiation of the document with a light beam. 2. The scanning optical apparatus according to claim 1, wherein irradiation is performed on the light detecting means to obtain a signal from the light detecting means. 4. The apparatus according to claim 1, further comprising a unit configured to detect an open / close state of the lid member by an operating member that contacts the lid member, wherein the light source control unit determines that the lid member is in a closed state by the unit. 4. The scanning device according to claim 3, wherein when the lid member is determined to be in an open state based on a signal from the light detection unit, irradiation from the light source is not performed. Optical device. 5. A light source control device according to claim 1, further comprising a selection unit configured to select whether to stop or continue irradiation of the light beam to the document, wherein the light source control unit determines that the lid member is in an open state based on a signal from the light detection unit. 5. The scanning optical apparatus according to claim 3, wherein the irradiation is performed when the continuation of the irradiation is selected by the selection unit. 6. The scanning device according to claim 3, wherein said light source control means is set so as to emit a light beam only to a predetermined light detection means position. Optical device.