JP4109101B2 - Exposure apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exposure apparatus that forms a latent image by performing optical writing on a photosensitive member, and an image forming apparatus including the exposure apparatus.
[0002]
[Prior art]
Conventionally, in image forming apparatuses such as copiers, printers, and facsimiles, image data from an original reading apparatus or the like is transferred onto a photosensitive member by a laser scanning device using a semiconductor laser light emitting element (hereinafter referred to as LD). There are various types of devices that write, develop a latent image on a photoreceptor, visualize it, and transfer it onto a transfer paper. The laser scanning device uses an LD as a light source, a deflector such as a polygon mirror that deflects laser light from the LD, a lens such as a collimator lens or a cylindrical lens, and a part of the laser beam on the photosensitive member. It comprises beam detecting means for determining the image writing position. These components are housed in a housing or the like for dust prevention.
[0003]
Further, in an image forming apparatus such as a copying machine, an image reading device that reads image information of a document is arranged at the upper part, and a laser scanning device is arranged at the lower part thereof, and replacement of parts in the laser scanning apparatus is performed. In some cases, an opening with a cover for replacing parts of the laser scanning device may be provided in the housing of the image reading device. Main replacement parts include a light source, a deflector, and beam detection means, and an opening is provided for each of them.
[0004]
By the way, the laser scanning device uses a laser beam as the name suggests, and it is extremely dangerous if it enters the eyes of a serviceman. Therefore, it is instructed to work after turning off the power switch or unplugging the power cord in the service manual or machine caution label, etc., but it can not be said that they are securely protected. Absent.
[0005]
Therefore, it is desirable that when the service person tries to access the laser scanning device, the laser emission is surely stopped. In accordance with this demand, for example, Japanese Patent Laid-Open No. 8-30062 proposes providing a switch for turning on / off the LD in conjunction with the attachment / detachment of the cover member. Thereby, the above-mentioned request can be satisfied functionally.
[0006]
[Problems to be solved by the invention]
However, if a switch is provided in each of the plurality of opening covers as in the above-described prior art, not only the cost is increased, but there is also a concern that the reliability is reduced due to an increase in the number of parts.
[0007]
The present invention has been made in view of the actual situation of the prior art, and a first object is to provide an exposure apparatus that can easily replace parts and cannot perform an optical writing operation during replacement work. It is to provide.
[0008]
A second object is to provide an image forming apparatus in which parts of an exposure apparatus can be easily replaced, and an optical writing operation cannot be performed during replacement work.
[0009]
[Means for Solving the Problems]
In order to achieve the first object, the first means includes a light source, a deflector for deflecting the beam emitted from the light source, and an image of the beam deflected and scanned by the deflector on the photosensitive member. A lens group; beam detection means for determining an image writing position on the photoconductor; and a housing for housing the light source, deflector, lens group, and beam detection means, and optical writing on the photoconductor. In the exposure apparatus for forming a latent image, a plurality of openings formed at an upper position of the housing, a plurality of first cover members for sealing the plurality of openings, and the plurality of openings A second cover member that covers at least a part of the first cover member, and a switch that is turned on and off in conjunction with the attachment and detachment of the second cover member, the switch when the second cover member is removed. stopping the emission of the light source And wherein the door.
[0011]
To achieve the second object, the second means comprises an image reading means for reading image information of the original, the image information from said image reading means on a photosensitive member and a writing exposure unit as a latent image, The exposure means includes a light source, a deflector for deflecting the beam emitted from the light source, a lens group for forming an image of the beam deflected and scanned by the deflector on the photoreceptor, and an image on the photoreceptor. A beam detector for determining a writing position; and a housing for housing the light source, the deflector, the lens group, and the beam detector. The housing is sealed by a part of the housing of the image reading unit. In the image forming apparatus, a plurality of openings formed at positions corresponding to the light source, the deflector, the lens group, and the beam detection unit of the housing of the image reading unit, and the plurality of openings are provided. A plurality of first caps for sealing Comprising a chromatography member, and a second cover member covering at least a portion of the plurality of first cover member, a switch for turning on and off in conjunction with the attachment and detachment of the second cover member, wherein the switch, the second The light emission of the light source is stopped when the cover member is removed .
[0012]
To achieve the second object, the third means is characterized in that said second cover member in the second means also serves as a cover for covering at least a portion of the components of said image reading means . Thus, by using the second cover member as a cover member that covers the constituent elements of the image reading means, a new cover member is not required, and the cost of the apparatus can be further reduced.
[0014]
To achieve the second object, the fourth means, the switch in the second or third means to stop the emission of the light source when removing the fixing member for fixing the second cover member It is characterized by that.
[0015]
To achieve the second object, the fifth means, the upper portion of the casing of the exposure means in the second to fourth means, is covered at the bottom of the housing of the image reading unit, wherein the opening It is characterized by being formed at the bottom.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a case where the embodiment of the present invention is applied to a digital copying machine will be described with reference to the drawings. FIG. 1 is an explanatory diagram for explaining the overall configuration of a digital copying machine according to an embodiment of the present invention, FIG. 2 is an explanatory diagram for explaining main components of an image reading device and a laser recording device, and FIG. 3 is a lens. FIG. 4 is a circuit diagram showing the electrical connection of the switch.
[0017]
As shown in FIG. 1, the digital copying machine is roughly divided into an image reading device I for reading image information from a document placed on a contact glass 135, and a semiconductor laser light emitting device positioned below the image reading device I. A laser scanning device 101 which is an optical writing device using an element (hereinafter referred to as LD) and an electrostatic latent image formed on the photosensitive drum 120 by the laser scanning device 101 are visualized to form an original on transfer paper A laser recording apparatus II provided with an image forming apparatus 102 for reproducing an image, and an automatic document feeder (hereinafter referred to as “automatic document feeder”) that is positioned above the image reading apparatus I and that feeds a plurality of set documents one by one onto the contact glass 135. (Referred to as ADF) III.
[0018]
The image reading apparatus I includes a scanner 130 that performs exposure scanning along a document, an illumination lamp 131 that illuminates the document, a plurality of mirrors 132 that are arranged to refract and guide reflected light from the document, and converts an optical signal into an electrical signal. A CCD (one-dimensional solid-state imaging device) 134, an imaging lens 133 that forms an image of a document on the CCD 134, and the like are included.
[0019]
After operating the numeric keypad (not shown) on the operation display unit 103 provided at the top of the digital copying machine to input copy data such as the number of copies, the copy start key (not shown) on the operation display unit 103 is pressed. As a result, the originals placed on the ADF III are sequentially supplied onto the contact glass 135 of the image reading apparatus I one by one.
[0020]
The original image is read by the image reading apparatus I through optical scanning by the scanner 130, converted into multi-gradation image data by an image processing unit of an image processing board (not shown), and further converted into binary image data. It is stored in an image memory (not shown). Next, the image data is read and output to the laser recording apparatus II.
[0021]
In the laser recording apparatus II, an image recording signal of binary image data is input to a laser driving unit (not shown) of the laser scanning apparatus 101, and a laser driver modulated and controlled according to the image recording signal blinks an LD (not shown) or Drive light intensity. Thus, the LD emits a light-modulated laser beam BM.
[0022]
The laser beam BM passes through a collimator lens and a cylindrical lens (not shown), is incident on the polygon mirror 113, is deflected by the constant speed rotation of the polygon mirror 113, the lens group 110, the mirror 110a (both see FIG. 2), and dust-proof glass (not shown). No.) is guided to the photosensitive drum 120, and the photosensitive drum 120 is scanned in parallel (main scanning direction) with the rotation axis of the photosensitive drum 120.
[0023]
A part of the laser beam BM deflected by the rotation of the polygon mirror 113 is projected onto an optical sensor 117 (see FIG. 2) which is a beam detecting means for determining an image writing position on the photosensitive drum 120, and the optical sensor A detection signal is output from 117.
[0024]
Around the photosensitive drum 120, an electrostatic photographic process unit such as a charging charger 121, a developing device 122, and a transfer belt 123 is attached. The photosensitive drum 120 uniformly charged by the charging charger 121 forms a latent image of a recorded image by exposure with the laser beam BM, and the formed latent image is developed by the developing device 122 to become a visible image.
[0025]
The transfer paper sent out from the paper feed tray 150 is aligned at the leading edge by the registration roller 152 and sent to the transfer unit in synchronism with the movement of the visible image formed on the photosensitive drum 120. The visible image formed on the photoconductive drum 120 is transferred onto the transfer paper to be conveyed under the action of the transfer belt 123. Thereafter, fixing processing is performed by the fixing roller 154, and the paper is discharged onto the paper discharge tray 156 by the paper discharge roller 155. On the other hand, after the transfer is completed at the transfer portion, the surface of the photosensitive drum 120 is cleaned by the cleaning unit 124.
[0026]
As shown in FIG. 2, a laser scanning device 101 is accommodated in a case 119 having an open upper surface, and an image reading device I is provided above the laser scanning device 101. The upper surface of the housing 119 is sealed by a reading base 136 that is a part of the housing of the image reading apparatus I. The reading base 136 is provided with openings 137 a and 138 a at positions corresponding to the LD unit 111 and the polygon mirror 113 in the laser scanning device 101 and at positions corresponding to the optical sensor 117. These openings 137a and 138a are normally covered with covers 137 and 138, and prevent light and dust from entering the housing 119 of the laser scanning apparatus 101. The covers 137 and 138 are covered with a lens cover 139 for the imaging lens 133 and the CCD 134, and the covers 137 and 138 can be attached and detached by removing the lens cover 139.
[0027]
As shown in FIG. 3, a pin 139 </ b> P is fixed downward on the bottom of the lens cover 139, passes through a hole 136 a provided in the reading base 136, and a switch 118 installed below the pin 118 </ b> P. The actuator 118a is pushed. As shown in FIG. 4, the switch 118 is disposed on a power supply line that connects the LD drive circuit 201 and the power supply 202. When the lens cover 139 is removed, the actuator 118a of the switch 118 is released from being pressed. Turn off. Thereby, the power source of the LD drive circuit 201 is cut off, and the light emission of the LD is surely stopped.
[0028]
Here, with reference to FIGS. 5 to 9, the configuration will be described in more detail while explaining the replacement work of the LD unit 111, the polygon mirror 113, and the optical sensor 117. FIG. First, after removing the ADF III and exposing the contact glass 135, as shown in FIG. 5, the stator members 140a and 141a such as screws are loosened to remove the original reference plates 140 and 141, and the contact glass 135 is removed. Remove from the upper opening 151 of the casing 150 of the copier body. Since the lens cover 139 is exposed in the upper opening 151 by removing the contact glass 135, the stator member 139a such as a screw is loosened to remove the lens cover 139 from the reading base 136. As described above, when the lens cover 139 is removed, the switch 118 is turned off, the power source of the LD drive circuit 201 is cut off, and the light emission of the LD can be stopped reliably.
[0029]
By removing the reading base 136, the covers 137 and 138 can be removed. At this time, the lens unit in which the imaging lens 133 and the CCD 134 are integrated can be removed as shown in FIG. 6, but it is not necessary to remove it.
[0030]
By loosening the stator member 137a such as a screw and removing the cover 137, the stator member 111a such as a screw fixing the LD unit 111 to the housing 119 can be loosened as shown in FIG. If is removed, the LD unit 111 can be replaced. Further, as shown in FIG. 8, the stator member 113a such as a screw fixing the polygon mirror 113 can also be loosened, so that the polygon mirror 113 can be easily replaced.
[0031]
On the other hand, as shown in FIG. 9, when the stator member 138 a such as a screw is loosened and the cover 138 is removed, the stator member 117 a such as a screw that fixes the optical sensor 117 to the housing 119 can be loosened. The sensor 117 can be easily replaced.
[0032]
Here, the sizes of the covers 137 and 138 and the lens cover 139 will be described with reference to FIG. FIG. 10 shows a state viewed from above before the lens cover 139 is removed in FIG. 6. The lens cover 139 has both the covers 137 and 138 so that only the covers 137 and 138 cannot be removed at the time of attachment. It is sufficient to cover at least a part. At this time, if the lens cover 139 is positioned so as to cover at least one of the plurality of stator members 137b, 138b for fixing the covers 137, 138 as shown in the drawing, the lens cover 139 is covered. Unless the cover is removed, the covers 137 and 138 cannot be removed, so that the cover 137 and 138 can be removed after the light emission of the LD is reliably stopped.
[0033]
In the above-described embodiment, the laser scanning device 101 is accommodated in the case 119 having an open upper surface, and the upper surface of the case 119 is sealed by the reading base 136 that is a part of the case of the image reading apparatus I. As described above, the casing is configured to cover the entire laser scanning apparatus 101, and openings are provided on the upper surface of the casing at positions corresponding to the LD unit 111, the polygon mirror 113, and the optical sensor 117, respectively. The same effect can be obtained by providing the covers 137 and 138 so as to cover these openings and covering at least a part of the collars 137 and 138 with the lens cover 139. Needless to say, the lens cover 139 may be sized to cover both the covers 137 and 138.
[0034]
In the embodiment described above, the pin 139P provided at the bottom of the lens cover 139 is passed through the hole 136a of the reading base 136 so as to push the actuator 118a of the switch 118. However, as shown in FIG. The actuator 118a may be pushed by attaching a stator member 139a such as a stitch for fixing the lens cover 139 to the reading base 136.
[0035]
【The invention's effect】
As described above, according to the present invention, it is possible to easily replace components and to perform an optical writing operation during replacement work .
[Brief description of the drawings]
FIG. 1 is an explanatory diagram for explaining an overall configuration of a digital copying machine according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram for explaining main configurations of an image reading apparatus and a laser recording apparatus.
FIG. 3 is an explanatory diagram showing an enlarged part of a lens cover portion.
FIG. 4 is a circuit diagram showing electrical connection of switches.
FIG. 5 is a partial perspective view showing a state in which the contact glass is removed for an operation for exchanging an LD unit or the like.
FIG. 6 is a partial perspective view showing a state in which a lens cover, a lens, and a CCD are removed.
FIG. 7 is a partial perspective view showing a state in which an LD unit and a mirror cover are removed.
FIG. 8 is a partial perspective view showing a state in which a mirror cover and a polygon mirror are removed.
FIG. 9 is a partial perspective view showing a state in which a sensor cover and an optical sensor are removed.
10 is a view showing a state viewed from above before the lens cover is removed in FIG. 6. FIG.
FIG. 11 is a diagram showing another example of operating a switch on / off.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 101 Laser scanning device 102 Image forming device 110 Lens group 113 Polygon mirror 111 LD unit 117 Optical sensor 118 Switch 119 Housing 120 Photoconductor drum 121 Charge charger 122 Developing device 123 Transfer belt 133 Imaging lens 134 CCD
136 Reading base 137, 138 Cover (first cover member)
137a, 138a Opening 139 Lens cover (second cover member)
154 Fixing roller I Image reading device
II Laser recorder
III Automatic document feeder (ADF)

Claims (5)

A light source, a deflector for deflecting the beam emitted from the light source, a lens group for forming an image of the beam deflected and scanned by the deflector on the photosensitive member, and an image writing position on the photosensitive member are determined. In an exposure apparatus comprising: a beam detection means for detecting a light source; a light source, a deflector, a lens group, and a housing that houses the beam detection means;
A plurality of openings formed at an upper position of the housing;
A plurality of first cover members for sealing the plurality of openings;
A second cover member covering at least a part of the plurality of first cover members;
A switch that turns on and off in conjunction with the attachment and detachment of the second cover member;
Equipped with a,
The exposure apparatus , wherein the switch stops light emission of the light source when the second cover member is removed . An image reading unit that reads image information of a document and an exposure unit that writes image information from the image reading unit as a latent image on a photosensitive member. The exposure unit deflects a light source and a beam emitted from the light source. A deflector, a lens group for forming an image of the beam deflected and scanned by the deflector on the photosensitive member, beam detecting means for determining an image writing position on the photosensitive member, the light source, and the deflection An image forming apparatus having a container, a lens group, and a housing for storing beam detecting means, wherein the housing is sealed by a part of the housing of the image reading means,
A plurality of openings formed at positions corresponding to the light source, the deflector, the lens group, and the beam detection unit of the housing of the image reading unit;
A plurality of first cover members for sealing the plurality of openings;
A second cover member covering at least a part of the plurality of first cover members;
A switch that turns on and off in conjunction with the attachment and detachment of the second cover member;
With
The switch to an image forming apparatus according to claim light emission of the light source be stopped when you remove the second cover member. The image forming apparatus according to claim 2, wherein the second cover member also serves as a cover that covers at least a part of the constituent elements of the image reading unit . The switch, the image forming apparatus according to claim 2 or 3, wherein the light emission of the light source be stopped when removing the fixing member for fixing the second cover member. Top of the casing of the exposure means, the covered at the bottom of the housing of the image reading means, one of claims 2 to 4 wherein the aperture is characterized by being formed on the bottom portion 1 The image forming apparatus described in the item .

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