JPH11160809A - Image reader and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the vibration control effect of the mirror of an optical system by providing a device with a reading mirror holding member holding a mirror for reading by magnetic force generated by at least either of a magnetic body member or itself. SOLUTION: Plural permanent magnets 50 are fixed to the back surfaces M1 of the mirrors M corresponding to the respective mirrors for reading and writing by adhesive agent or the like. The magnet 50 is one part of a sphere, to put it concretely, it is shaped by cutting the sphere by a plane. Then, the plane surface parts of the magnets 50 are fixed to the surfaces M1 of the mirrors M and the spherical surfaces thereof are made to face a bracket 51 so that the mirrors M are held by the bracket 51 by the magnetic force generated by the magnets 50. At least the part of the bracket 51 brought into contact with the magnets 50 is constituted of a magnetic body. Then, two mirrors M are held at two places of the bracket 51 provided with an almost V-shaped cross section in order to suitably load the mirror for reading on a half-rate carriage. Besides, the reflection surfaces M2 of the mirrors M are mutually crossed by 45 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image reading apparatus and an image forming apparatus, and more particularly to an improvement in a structure for holding a reading mirror used in an optical system.

[0002]

2. Description of the Related Art In an optical system of an image reading apparatus, generally, a carriage provided with a lamp and a reading mirror is moved to scan an entire document placed on a platen glass. Then, the light reflected from the original by the irradiation light emitted from the lamp is reflected by a reading mirror and guided to a reading unit such as an image sensor. When the carriage is moved in this manner, the reading mirror may be vibrated due to the operation of the movement driving source or the vibration accompanying the movement. However, if the reading mirror vibrates, the image read by the reading unit is deteriorated.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 7-319077, an apparatus has been proposed in which an elastic foam is used to press a reading mirror against a holding portion on a carriage to control vibration. ing. However, even if the elastic foam alone can attenuate the vibration, the generation of the vibration cannot be prevented, and the weak vibration will continue. In addition, the work of mounting the elastic foam is required, and the mounting of the mirror becomes complicated.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and provides an image reading apparatus and an image forming apparatus in which a mirror of an optical system has a high damping effect and a mirror can be easily mounted. The purpose is to provide.

[0005]

According to the present invention, there is provided an image reading apparatus comprising: an irradiating means for emitting irradiation light for irradiating an original; and at least one reflecting light reflected from the original by the irradiation light irradiated by the irradiating means. Two reading mirrors, a magnetic member fixed to the reading mirror, and a magnetic member at least in part, and the reading mirror is formed by a magnetic force generated by at least one of the magnetic member and itself. And a reading means for reading reflected light from the reading mirror.

In this image reading apparatus, the reading mirror is held on the holding member by the magnetic force between the magnetic member fixed to the reading mirror and the reading mirror holding member. Accordingly, the vibration of the reading mirror is suppressed, the displacement of the read image is suppressed, and the attachment of the reading mirror to the holding member is simplified.

The magnetic member and the magnetic member of the reading mirror holding member are preferably brought into substantially point contact with each other. According to this, the contact area between them can be small,
Since the reading mirror can be slid with respect to the holding member with a small force, the positioning of the reading mirror is simplified.

[0008] An image forming apparatus according to the present invention includes the above image reading device and an image forming unit for forming an image on a sheet based on the reflected light read by the reading means.

In this image forming apparatus, an image is formed on the basis of the reflected light whose positional deviation has been suppressed by the above-described image reading apparatus, so that the positional deviation of the formed image can be suppressed.

According to another aspect of the present invention, there is provided an image forming apparatus, comprising: an irradiating unit for irradiating an original, and at least one reading mirror for reflecting light reflected from the original by the irradiating light emitted by the irradiating unit. A magnetic member fixed to the reading mirror, and a magnetic member provided at least in part, and holding the reading mirror by a magnetic force generated by at least one of the magnetic member and itself. Mirror holding member, reading means for reading reflected light from the reading mirror, writing means for emitting latent image writing light based on the reflected light read by the reading means, At least one writing mirror that reflects the latent image writing light, a magnetic member fixed to the writing mirror, and a magnetic material provided at least in part, and the magnetic member and itself. A writing mirror holding member for holding the writing mirror by at least one of the generated magnetic forces, an image carrier irradiated with the latent image writing light from the writing unit, and the latent image writing light And a transfer unit that transfers a visible image formed on the image carrier to a sheet.

In this image forming apparatus, not only the reading mirror is held on the reading mirror holding member but also the writing is performed by the magnetic force between the magnetic member fixed to the reading mirror and the reading mirror holding member. The writing mirror is held on the writing mirror holding member by a magnetic force between the magnetic member fixed to the writing mirror and the writing mirror holding member. This allows
Vibration of both the reading mirror and the writing mirror is suppressed, the displacement between the read image and the formed image is suppressed, and the reading mirror is easily attached to the holding member.

Further, the image forming apparatus according to the present invention comprises: a writing unit for emitting a latent image writing light based on an image forming signal;
At least one writing mirror for reflecting the latent image writing light from the writing means, a magnetic member fixed to the writing mirror, and a magnetic material at least in part; A writing mirror holding member for holding the writing mirror by a magnetic force generated by at least one of a body member and itself; an image carrier irradiated with latent image writing light from the writing unit; A latent image forming unit configured to form a visible image on the image carrier irradiated with the latent image writing light; and a transfer unit configured to transfer a visible image formed on the image carrier to a sheet. It may be something.

Further, the image forming apparatus according to the present invention comprises: an irradiating unit for irradiating the original with irradiation light; and at least one mirror for reflecting light reflected from the original by the irradiation light irradiated by the irradiating unit; A magnetic member fixed to the mirror, a mirror holding member that includes a magnetic material at least in part, and holds the mirror by a magnetic force generated by at least one of the magnetic member and itself; An image carrier irradiated with reflected light from
The apparatus may include a visual image forming unit that forms a visual image on the image carrier irradiated with the reflected light, and a transfer unit that transfers the visual image formed on the image carrier to a sheet.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1. First Embodiment A. First Embodiment FIG. 1 shows a main part of an image forming apparatus (copier) according to a first embodiment of the present invention. In FIG. 1, the rear side is the rear side and the front side is the front side, and the user operates the copying machine on the front side. Code 8
Indicates an upper part of a cabinet of a copying machine, that is, a cabinet. A platen glass 10 is attached to an upper portion 8 of the housing. The document D is placed on the platen glass 10 with the image to be copied facing down. A platen cover 7 that can approach and separate from the platen glass 10 is disposed above the platen glass 10. As shown in FIG. 1, when approaching the platen glass 10, the platen cover 7 presses the document D against the platen glass 10.

Below the platen glass 10, a full rate carriage 11 and a half rate carriage 12 are movably arranged. Full rate carriage 11
In the half-rate carriage 12, reading mirrors 16 and 17 are arranged.

The linear lamp 14 is, for example, a halogen lamp or a rare gas lamp, and is a long straight tube lamp extending in a direction perpendicular to the plane of FIG. A reflective concave mirror 14a is provided below the linear lamp 14 so that light emitted from the linear lamp 14
0, the document D is illuminated at one time in a band shape over the entire width direction (perpendicular to the plane of the drawing). The light reflected from the document D is reflected by the reading mirrors 15, 16, and 17 and forms an image on the line image sensor (reading unit) 18 by the lens 13.

The full-rate carriage 11 is moved over the entire lateral direction (sub-scanning direction) of the original D by a driving source (not shown), whereby the linear lamp 14 irradiates the entire surface of the original D. By the same driving source, the half-rate carriage 12 is moved in the same direction as the full-rate carriage 11 at half the speed of the full-rate carriage 11, and the optical path from the original D to the lens 13 via the reading mirrors 15, 16, 17 is read. Keep the length constant.

The line image sensor 18 is a solid-state image sensor, specifically, a CCD image sensor, extends in a direction perpendicular to the plane of FIG. 1, and has a number of CCD photosensitive pixels serially arranged along the longitudinal direction. I have. Each CCD photosensitive pixel of the line image sensor 18 performs photoelectric conversion upon receiving light, and the image reading signal thus obtained is supplied to an image processing unit (reading means) 19. The image processing unit 19 converts and corrects the image reading signal to generate an image writing signal. This image writing signal is supplied to a latent image writing device (writing unit, ROS) 20 of an image forming unit attached to the copying machine as described later.

B. 1. Image Forming Unit In FIG. 1, reference numeral 1 denotes a photosensitive drum as an image carrier. Around the photosensitive drum (image carrier) 1, a charging corotron 2, a latent image writing device 20, a developing device (developing image forming means) 3, a transfer roll (transfer means) 4, a cleaner 5, and a charge removing roll 6 are provided. Are located. The photoconductor drum 1 is rotated in the direction indicated by the arrow in the figure, and accordingly, the surface of the photoconductor drum 1 is uniformly charged by the charging corotron 2.

The latent image writing device 20 irradiates the photosensitive drum 1 with a laser beam in response to an image writing signal. As a result, a latent image corresponding to the image on the document D is written on the surface of the photosensitive drum 1. Then, the toner supplied from the developing device 3 is electrostatically attached to the latent image to form a visible toner image. Photoconductor drum 1
And a transfer mechanism between the transfer roll 4
A sheet S such as paper or an OHP sheet is conveyed. Then, the toner image on the photosensitive drum 1 is electrostatically transferred to the sheet S by the electric field generated by the transfer roll 4. Note that a two-dot chain line in FIG. 1 indicates a path along which the sheet S is conveyed.

Thereafter, the sheet S is conveyed to the heat fixing device 22. The heat fixing device 22 includes a heating roll 23 and a pressure roll 24 arranged substantially in parallel with each other, and the toner image is heated and pressed by the sheet S passing through the nip between the two. Is fixed on the sheet S. A discharge roll 36 for discharging the sheet S to a discharge tray 35 outside the cabinet of the image forming apparatus is provided downstream of the heat fixing device 22. The sheet S on which the toner image is fixed is discharged to the discharge tray 35. Is done. on the other hand,
The toner remaining on the photosensitive drum 1 without being transferred to the sheet S is removed by a cleaner 5 such as a blade, and thereafter, the surface of the photosensitive drum 1 is neutralized by a neutralizing roll 6 for the image forming process again. Is done.

Reference numeral 30 denotes a sheet storage tray for storing sheets S first. The sheet S is pulled out from the sheet storage tray 30 toward the main transport path 31. The main transport path 31 is provided with a plurality of pairs of transport rolls 32, a pair of pre-registration rolls 33 and registration rolls 34, which are used to transfer the sheet S to the photosensitive drum 1 and the transfer roll 2. It is conveyed toward the transfer nip between the two.

FIG. 2 shows a specific configuration of the latent image writing device 20. The latent image writing device 20 includes a laser 41 such as a semiconductor laser that is controlled to emit a laser beam according to an image writing signal. The laser light emitted from the laser 41 is divided into a collimator lens 42 and a cylindrical lens 4.
3, and converges on the side surface of the polygon mirror 44 rotated by the motor 44a. Then, the laser light is reflected by the side surface of the polygon mirror 44, and the spherical lens 4
5 through the toric lens 46 and the writing mirror 47
Then, the light is irradiated on the surface of the photosensitive drum 1.

In addition to the above image forming unit,
There is an image forming unit using a photoreceptor belt instead of the photoreceptor drum 1, using a transfer corotron instead of the transfer roll 4, and using a pressure fixing device instead of the heat fixing device 22. The present invention is also applicable to these image forming units.

C. Mirror mounting structure As described above, the reading mirrors 15 to 17 are mounted on the carriage 11 or 12, and the writing mirror 47 is provided on the latent image writing device 20. Hereinafter, various suitable mounting structures of these mirrors 15 to 17, 47 will be described. The following mounting structure is preferably applied to all of the mirrors 15 to 17 and 47. However, the present invention is not limited to this. At least one of the mirrors is mounted as follows. It should just be.

FIG. 3 shows a rear surface M1 of a flat mirror M corresponding to the reading mirrors 15 to 17 and the writing mirror 47.
Is shown. A plurality of permanent magnets (magnetic members) 50 are fixed to the back surface M1, for example, with an adhesive or a double-sided tape. As shown in FIG. 4, the magnet 50 is a part of a sphere. More specifically, it has a shape obtained by cutting a sphere by a plane, and the plane portion is fixed to the back surface M1 of the mirror M. Then, the spherical surface of the magnet 50 is directed to the bracket 51, and the mirror M is held on the bracket 51 by the magnetic force generated by the magnet 50. In the bracket 51,
At least a portion in contact with the magnet 50 is made of a magnetic material.

In FIG. 4, the half-rate carriage 12
A bracket 51 having a substantially V-shaped cross section so as to be suitable for mounting the reading mirrors 16 and 17 on (see FIG. 1).
The two mirrors M are held at the two positions, respectively, so that the reflection surfaces M2 of the mirrors M cross each other at an angle of 45 °. However, the bracket 51 is suitable for the reading mirror 15 mounted on the full rate carriage 11 and the writing mirror 47 provided on the latent image writing device 20.
May be changed so that a single mirror M is held on it.

FIG. 5 shows another mounting structure. In this mounting structure, the first bracket 52 is fixed to the back surface M1 of the mirror M so as to be in intimate contact, and the same magnet 50 as described above is fixed to the first bracket 52. These may be fixed by, for example, an adhesive or a double-sided tape. And
The spherical surface of the magnet 50 faces the second bracket 53. Also in the second bracket 53, at least the surface facing the magnet 50 is made of a ferromagnetic material, and the mirror M is moved by the magnetic force generated by the magnet 50 so that the second bracket 53
3 is held. The structure using two brackets shown in FIG. 5 may be applied to the structure requiring two mirrors M shown in FIG.

The surface of the first bracket 52 to which the back surface M1 of the mirror M is fixed may be processed so as to have a good flatness. According to this, even if the rigidity of the mirror M is small, its bending is prevented, and as a result, a good read image is read by the line image sensor 18 or a good latent image is formed on the photosensitive drum 1. It is possible. The first bracket 52 may not be made of a ferromagnetic material.

FIG. 6 shows another mounting structure. In this mounting structure, a bracket 54 at least partially made of a ferromagnetic material is fixed to a flat surface 55 of a housing (for example, the housing of the latent image writing device 20),
The bracket 54 is attracted to the magnet 50 fixed to the bracket 1.

FIG. 7 shows still another mounting structure. In this mounting structure, the magnet 5 fixed to the back surface M1 of the mirror M
Reference numeral 0 faces a flat surface 56 of a housing made of a ferromagnetic material (for example, the housing of the latent image writing device 20), and the mirror M is held by the housing by the magnetic force of the magnet 50.

In the above-described embodiment, the plane of the magnet 50 is fixed to the mirror M or the first bracket 52, and the spherical surface of the magnet 50 is attached to the holding member (bracket 5) made of a ferromagnetic material.
1, 53, 54, the housing), but the plane of the magnet 50 may be fixed to these holding members. In this case, the holding member may not be made of a ferromagnetic material. 8 to 11 show an example in which the plane of the magnet 50 is fixed to the holding member of the example shown in FIGS.

In the examples shown in FIGS. 8, 10 and 11,
A magnetic plate (magnetic member) 60 made of a ferromagnetic material is fixed to the back surface M1 of the mirror M by, for example, an adhesive or a double-sided tape so as to be in close contact therewith. , The mirror M is held. In the example shown in FIG. 9, the first bracket 52 is made of a ferromagnetic material, and the first bracket 52 is made of a ferromagnetic material.
Is attracted to the magnet 50, whereby the mirror M is held.

The surface of the magnetic plate 60 to which the rear surface M1 of the mirror M is fixed, as well as the first bracket 52, is preferably processed to have a good flatness. According to this, even if the rigidity of the mirror M is small, its bending is prevented, and as a result, a good read image is read by the line image sensor 18 or a good latent image is formed on the photosensitive drum 1. It is possible.

FIG. 12 shows still another example. This example is a modification of the example shown in FIG. 6, in which an elastic vibration absorber 61 is interposed between a mirror M and a bracket 54 as a holding member. The elastic vibration absorber 61 may be fixed to either the mirror M or the bracket 54. The elastic vibration absorber 61 is made of a material having a high elasticity such as a polyurethane foam, and when the magnet 50 attracts the bracket 54, it contracts by receiving the force. Then, if vibration is generated, it is attenuated. In another example, such an elastic vibration absorber 61 may be interposed between members on both sides of the magnet 50.

In any of the above examples, the magnet 50 is a part of a sphere, and the spherical surface of the magnet 50 and the plane of the ferromagnetic material are in contact with each other, so that the mounting structure of the mirror M is realized. Therefore,
The magnet 50 and the ferromagnetic material are substantially in point contact with each other. In order to realize such a point contact, the magnet 50 may be a sphere that is not cut.

In this image reading apparatus, since the holding of the mirror M is achieved by the magnetic force generated by the magnet 50, the generation of the vibration of the mirror M is suppressed, and even if it occurs, the continuation of the vibration is suppressed. . Therefore, if this structure is applied to the reading mirrors 15, 16, and 17, the vibration accompanying the operation and movement of the drive source of the carriage is suppressed, and the displacement of the image read by the line image sensor 18 is suppressed. The quality of the image formed on the sheet S by the image forming unit is also improved. Further, when the present invention is applied to the writing mirror 47 provided in the latent image writing device 20, the writing mirror 47 is damped even if the movable part of the image forming apparatus is vibrated. Is suppressed, and the quality of an image formed on the sheet S is also improved.

The number of magnets 50 is arbitrarily determined according to factors such as the length and weight of the mirror M. Mirror M
Is preferably a position where both the primary vibration and the secondary vibration of the mirror M can be suppressed. It is even better if higher-order vibrations can be suppressed.

In this image reading apparatus, the mirror M is mounted by the magnetic force of the magnet 50, thereby greatly simplifying the mounting operation. Further, if the magnet 50 is slid with respect to the opposing plane, the mirror M can be easily positioned. In particular, by bringing the magnet 50 and the ferromagnetic material into point contact with each other, the contact area can be reduced, and the force required for sliding the magnet 50 can be reduced, so that the alignment is very easy.

2. Second Embodiment FIG. 13 shows an image reading device (image scanner) according to a second embodiment of the present invention. This image scanner is almost equivalent to the image forming apparatus shown in FIG. 1 having no image forming unit, and the components are denoted by the same reference numerals as in FIG. 1, and detailed description thereof will be omitted. In this embodiment, the image processing unit 19 generates image data based on an image reading signal output from the line image sensor 18, and transmits the image data to an external computer or the like via the interface 70. ing.

The mounting structure of the mirror M described above can be applied to the reading mirrors 15, 16, and 17 used in the image scanner, thereby suppressing the vibration accompanying the operation and movement of the drive source of the carriage. Thus, the displacement of the image read by the line image sensor 18 is suppressed, and the image data transmitted to the outside is improved.

3. Third Embodiment FIG. 14 shows an image forming apparatus (printer) according to a third embodiment of the present invention. This printer is substantially equivalent to the image forming apparatus shown in FIG.
Each component is denoted by the same reference numeral as in FIG. 1 and detailed description thereof is omitted.

The latent image writing device 20 has, for example, the structure shown in FIG. 2, and receives image data (image forming signal) from an external computer or the like via an interface 71 shown in FIG. Then, based on the image data,
A latent image is written on the photosensitive drum 1, and as a result, an image is formed on the sheet S.

Write mirror 4 used in this printer
7 as well, the above-described mounting structure of the mirror M is applicable. Then, even if the movable part of the image forming apparatus is vibrated, the writing mirror 47 is damped, so that the displacement of the written image is suppressed, and the quality of the image formed on the sheet S is also improved. .

4. Fourth Embodiment FIG. 15 shows an image forming apparatus (copier) according to a fourth embodiment of the present invention. This copying machine is not provided with the line image sensor 18, image processing unit 19, and latent image writing device 20 of the copying machine shown in FIG. 1, and does not generate an image reading signal or an image writing signal. Instead, the reflected light from the document D transmitted through the lens 13 is reflected by the mirror 80, and a latent image is written on the surface of the photosensitive drum 1 with the reflected light. Other elements are common to the copying machine of FIG.

The above-described mounting structure of the mirror M is applicable not only to the reading mirrors 15, 16, 17 but also to the mirror 80. Then, even if the movable part of the image forming apparatus vibrates, these mirrors 15, 16, 17, 8
Since 0 is damped, the displacement of the written image is suppressed,
The quality of the image formed on the sheet S is also improved.

[0047]

As described above, according to the present invention,
The vibration damping effect of the mirror of the optical system can be improved, and the work of mounting the mirror can be simplified.

[Brief description of the drawings]

FIG. 1 is a front view showing a main part of a copying machine which is an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing in detail a configuration of a latent image writing device of the image forming apparatus shown in FIG.

FIG. 3 is a rear view showing a mirror usable in the present invention.

FIG. 4 is a side view showing an example of the mounting structure of the mirror.

FIG. 5 is a side view showing another example of the mounting structure of the mirror.

FIG. 6 is a side view showing another example of the mirror mounting structure.

FIG. 7 is a side view showing another example of the mirror mounting structure.

FIG. 8 is a side view showing another example of the mounting structure of the mirror.

FIG. 9 is a side view showing another example of the mounting structure of the mirror.

FIG. 10 is a side view showing another example of the mounting structure of the mirror.

FIG. 11 is a side view showing another example of the mirror mounting structure.

FIG. 12 is a side view showing another example of the mounting structure of the mirror.

FIG. 13 is a front view showing a main part of an image scanner which is an image reading device according to a second embodiment of the present invention.

FIG. 14 is a front view showing a main part of a printer which is an image forming apparatus according to a third embodiment of the present invention.

FIG. 15 is a front view showing a main part of a copying machine which is an image forming apparatus according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photoreceptor drum (image carrier), 3 ... Developer (visible image forming means), 4 ... Transfer roll (transfer means), 10 ... Platen glass, 11, 12 ... Carriage, 14 ... Linear lamp (irradiation means) Reference numerals 15 to 17: reading mirror, 18: line image sensor (reading means), 19: image processing unit (reading means), 20: latent image writing device (writing means), 4
7: mirror for writing, 50: permanent magnet (magnetic member), 5
1, 53, 54: bracket (holding means, reading mirror holding means, writing mirror holding means), 52: first bracket (magnetic member), 55, 56: flat surface of housing (holding means, reading Mirror holding means, writing mirror holding means), 60: magnetic plate (magnetic member), 80: mirror, D: original, M: mirror, S: sheet

Claims (9)

[Claims] An irradiating means for irradiating an original; irradiating means for irradiating the original; at least one reading mirror for reflecting light reflected from the original by the irradiating light emitted from the irradiating means; fixed to the reading mirror; A magnetic material member, a magnetic material member provided at least in part, and a reading mirror holding member for holding the reading mirror by a magnetic force generated by at least one of the magnetic material member and itself; An image reading apparatus, comprising: reading means for reading reflected light from a mirror. 2. The image reading apparatus according to claim 1, wherein the magnetic member and the magnetic member of the reading mirror holding member are substantially in point contact with each other. 3. An image forming apparatus comprising: the image reading apparatus according to claim 1; and an image forming unit that forms an image on a sheet based on reflected light read by the reading unit. . 4. An irradiating means for irradiating the original with irradiation light, at least one reading mirror for reflecting light reflected from the original by the irradiating light irradiated by the irradiating means, and fixed to the reading mirror. A magnetic material member, a reading mirror holding member having a magnetic material at least in part, and holding the reading mirror by a magnetic force generated by at least one of the magnetic material member and itself; Reading means for reading the reflected light from the mirror; writing means for emitting a latent image writing light based on the reflected light read by the reading means; and at least reflecting the latent image writing light from the writing means. One writing mirror, a magnetic member fixed to the writing mirror, and a magnetic member at least in part, wherein at least one of the magnetic member and itself is generated A writing mirror holding member for holding the writing mirror by magnetic force, an image carrier irradiated with the latent image writing light from the writing means, and an image carrier irradiated with the latent image writing light An image forming apparatus comprising: a visible image forming unit that forms a visible image on a body; and a transfer unit that transfers a visible image formed on the image carrier to a sheet. 5. The magnetic member fixed to the reading mirror and the magnetic member of the reading mirror holding member are substantially in point contact with each other, and the magnetic member fixed to the writing mirror and the magnetic member are fixed to the writing mirror. The image forming apparatus according to claim 4, wherein the magnetic bodies of the writing mirror holding member are substantially in point contact with each other. 6. A writing unit for emitting a latent image writing light based on an image forming signal, at least one writing mirror for reflecting the latent image writing light from the writing unit, and the writing A magnetic member fixed to a mirror for use, and a write mirror having a magnetic material at least in part and holding the write mirror by a magnetic force generated by at least one of the magnetic member and itself. A holding member, an image carrier irradiated with the latent image writing light from the writing unit, a visible image forming unit configured to form a developed image on the image carrier irradiated with the latent image writing light, An image forming apparatus comprising: a transfer unit configured to transfer a visible image formed on an image carrier to a sheet. 7. The image forming apparatus according to claim 6, wherein the magnetic member fixed to the writing mirror and the magnetic member of the writing mirror holding member are substantially in point contact with each other. . 8. An irradiating unit for irradiating the original with irradiation light, at least one mirror for reflecting light reflected from the original by the irradiation light irradiated by the irradiating unit, and a magnetic member fixed to the mirror And a mirror holding member for holding the mirror by a magnetic force generated by at least one of the magnetic member and itself, and an image irradiated with light reflected from the mirror. A carrier, a visible image forming means for forming a visible image on the image carrier irradiated with the reflected light, and a transfer means for transferring the visible image formed on the image carrier to a sheet. Image forming apparatus. 9. The image forming apparatus according to claim 8, wherein the magnetic body member fixed to the mirror and the magnetic body of the mirror holding member are substantially in point contact with each other.