JP2009083467A - Exposure apparatus and image forming apparatus provided with the exposure apparatus - Google Patents

Abstract

Even when a lens array and a light emitting element are used, the focus is adjusted to a higher degree.
Lens arrays 4a ₁ , 4a ₂ , 4a ₃ and light emitting elements 4b ₁ , 4b ₂ , 4b _{3 which} are two-dimensionally arranged in a matrix are supported by a light emitting element support member 4d. By moving the light emitting element supporting member 4d in θ direction at the third position adjusting mechanism 52e, the sub-scanning direction of the exposure position of the center of the light emitting element 4b ₂ is adjusted. Further, by moving the light emitting element support member 4d in the δ and ε directions by the first and second position adjusting mechanisms 52c and 52d, the exposure positions in the sub-scanning direction of the light emitting elements 4b ₁ and 4b ₃ at both ends are adjusted. Is done. Thereby, the exposure apparatus 4 is adjusted to the state where the light from each of the light emitting elements 4b ₁ , 4b ₂ , 4b ₃ is in focus.
[Selection] Figure 5

Description

  The present invention relates to a technical field of an exposure apparatus having a light emitting element array having a plurality of light emitting elements and a lens array having a plurality of lenses for imaging light from the light emitting elements. The present invention also relates to the technical field of electrophotographic image forming apparatuses such as copying machines, facsimiles, and printers that include the exposure apparatus and use a liquid developer.

  Conventionally, an exposure apparatus having a light emitting element array having a plurality of light emitting elements arranged two-dimensionally and a lens array having a plurality of lenses for imaging light from the light emitting elements has been proposed (for example, patents). Reference 1 and 2). In the exposure apparatus described in Patent Document 1, the light emitting element array and the lens array are arranged in a first direction that is a main scanning direction and a second direction that is a scanning direction orthogonal or substantially orthogonal to the first direction. Has been appointed. Then, the photoreceptor is exposed with two rows of spots by light from the light emitting elements. Further, in the exposure apparatus described in Patent Document 2, light from a plurality of rows of light emitting elements is irradiated onto the photoconductor in a line shape to form a latent image. In this case, light from all the light emitting elements is imaged on the photosensitive member by one optical system lens.

When a lens array is used, it is possible to use a light emitting element larger than a conventional exposure apparatus that does not use a lens array. Therefore, the use of the lens array provides advantages such as an increase in exposure intensity, extended life, and expanded choices of light emitting elements.
JP-A-6-278314. JP 2001-63139 A.

By the way, when a lens array is used, it is difficult to focus light from a light emitting element onto a photoconductor. Therefore, when an exposure apparatus having a light emitting element array and a lens array that are two-dimensionally arrayed is incorporated in an image forming apparatus, the focus may not be achieved. For this reason, the number of exposure apparatuses that satisfy and pass a predetermined standard for focusing is reduced, and there is a problem that the yield of the exposure apparatus is poor.
However, with the exposure apparatuses described in Patent Documents 1 and 2, it is difficult to effectively solve this problem.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an exposure apparatus that can achieve higher focus even when a lens array and a light emitting element are used, and an image including the exposure apparatus. A forming apparatus is provided.

  In order to solve the above-described problems, an exposure apparatus and an image forming apparatus according to the present invention include an exposure position adjustment mechanism that adjusts an exposure position on a photosensitive member by moving a support member that supports a light emitting element array and a lens array. I have. Thereby, the exposure position of each light emitting element can be set to a focused position. Therefore, in combination with the above-described advantages of the lens array, it is possible to draw a good latent image in focus on the image carrier.

In the present invention, the exposure position adjustment mechanism is provided with a rotation exposure position adjustment unit that rotates the support member described above about the axis in the first direction. Thereby, the exposure position of each light emitting element in the second direction orthogonal to or substantially orthogonal to the first direction can be easily set to a more highly focused position. The first direction is preferably along the longitudinal direction of the photoreceptor.

  Further, in the present invention, the exposure position adjustment mechanism is provided with a second direction exposure position adjustment unit that moves the support member in the second direction described above. As a result, the exposure position of each light emitting element can be easily set to a more highly focused position.

  Further, in the present invention, the one end of the support member in the first direction is supported at two points in the second direction on the photosensitive member or the flange supporting the photosensitive member, or the one end of the support member is supported. The photosensitive member or the flange supporting the photosensitive member is supported at two or more points in the second direction, and the other end of the supporting member is supported at the photosensitive member or the flange supporting the photosensitive member at one or more points. Thereby, it becomes possible to make a rotation exposure position adjustment mechanism into a simple structure. In particular, by supporting the light emitting element array and the lens array on the flange that supports the photoconductor, the influence of vibration generated from the photoconductor can be suppressed, and stable writing of an image becomes possible.

  Furthermore, in the present invention, the maximum width in the second direction of the support point at one side end of the support member supported by the photosensitive member or the flange supporting the photosensitive member is irradiated with light from the light emitting element. Is set to be larger than the maximum width of the irradiation region in the second direction. Therefore, stable positioning of the exposure apparatus 4 can be performed. Moreover, the adjustment amount of the irradiation position of each light emitting element array and each lens array becomes small with respect to the position adjustment operation amount of each light emitting element and each lens array. This makes it possible to adjust the irradiation position of each light emitting element array and each lens array more finely, more accurately, and more easily.

  Furthermore, in the present invention, the exposure position adjusting mechanism moves the light emitting element array and the lens array in a direction orthogonal to both the first and second directions described above. An adjustment unit is provided. This also makes it possible to easily set the exposure position of each light emitting element to a more focused position.

  In addition, since the exposure position of each light emitting element can be set to a focused position, the number of exposure apparatuses that fail when the exposure apparatus is incorporated into the image forming apparatus can be reduced. Therefore, the yield of the exposure apparatus can be improved.

  Furthermore, by applying the exposure apparatus of the present invention, which can set the exposure position of each light emitting element to a focused position, to the exposure apparatus of the image forming apparatus using a liquid developer, the development electric field is relatively low. Even in a weak 1-dot width vertical line (second direction) image, it is possible to suppress the disturbance caused by the rib of the liquid carrier caused by using the liquid developer.

  Further, in order to adjust the exposure position in the exposure apparatus and the image forming apparatus according to the present invention, the support member that supports the light emitting element array and the lens array is moved in the second direction, so that the second position at the exposure position is adjusted. Adjust the center position of the direction. Next, the positions of both end portions in the second direction described above at the exposure position are adjusted. Thereby, the exposure position of each light emitting element can be more easily set to a focused position. In particular, by adjusting the positions of both end portions in the second direction at the exposure position by rotating about the axis in the first direction, the exposure position of each light emitting element can be further enhanced. It can be easily set to the in-focus position.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram schematically and partially showing an example of an embodiment of an image forming apparatus according to the present invention.
As shown in FIG. 1, the image forming apparatus 1 of this example includes a photoreceptor 2Y that is a latent image carrier of yellow (Y), magenta (M), cyan (C), and black (K) arranged in tandem. , 2M, 2C, 2K. Here, in each of the photoreceptors 2Y, 2M, 2C, and 2K, 2Y represents a yellow photoreceptor, 2M represents a magenta photoreceptor, 2C represents a cyan photoreceptor, and 2K represents a black photoreceptor. Similarly, the members of the respective colors are represented by adding Y, M, C, and K of the respective colors to the reference numerals of the members.
Each of the photoreceptors 2Y, 2M, 2C, and 2K is composed of a photoreceptor drum in the example shown in FIG. Each of the photoconductors 2Y, 2M, 2C, and 2K can also be configured as an endless belt.

  These photoreceptors 2Y, 2M, 2C, and 2K are configured to rotate clockwise as indicated by an arrow α in FIG. 1 during operation. Charging devices 3Y, 3M, 3C, and 3K are provided around the photoreceptors 2Y, 2M, 2C, and 2K. Further, exposure devices 4Y, 4M, 4C, and 4K and developing devices 5Y and 5M are sequentially arranged from the charging devices 3Y, 3M, 3C, and 3K in the rotational directions of the photosensitive members 2Y, 2M, 2C, and 2K, respectively. , 5C, 5K, photoreceptor squeeze devices 6Y, 6M, 6C, 6K, primary transfer devices 7Y, 7M, 7C, 7K, and static eliminators 8Y, 8M, 8C, 8K. Although not shown, a photoconductor cleaning device is provided between each of the static eliminating devices 8Y, 8M, 8C, and 8K and each of the charging devices 3Y, 3M, 3C, and 3K.

  Further, the image forming apparatus 1 includes an endless intermediate transfer belt 10 that is an intermediate transfer medium. The intermediate transfer belt 10 is stretched around a belt driving roller 11 and a pair of driven rollers 12 and 13 to which a driving force of a motor (not shown) is transmitted, and is provided to be able to rotate counterclockwise in FIG. In that case, the belt driving roller 11 and one driven roller 12 are arranged adjacent to each other with a predetermined interval in the moving direction (from bottom to top in FIG. 1) indicated by the arrow of the recording material such as paper being conveyed. It is installed. Further, the belt driving roller 11 and the other driven roller 13 are arranged apart from each other along the tandem arrangement direction of the photosensitive members 2Y, 2M, 2C, and 2K. Further, the intermediate transfer belt 10 is given a predetermined tension by a tension roller 14 so that slack is removed.

  In the image forming apparatus 1 of this example, the photoreceptors 2Y, 2M, 2C, and 2K and the developing devices 5Y, 5M, 5C, and 5K have colors Y, M, C, and C from the upstream side in the moving direction of the intermediate transfer belt 10, respectively. Although arranged in the order of K, the arrangement order of these colors Y, M, C, and K can be arbitrarily set.

  In the vicinity of the primary transfer devices 7Y, 7M, 7C, and 7K on the downstream side in the rotation direction of the intermediate transfer belt 10 from the primary transfer devices 7Y, 7M, 7C, and 7K, intermediate transfer belt squeeze devices 15Y, 15M, and 15C, respectively. , 15K are disposed. Further, a secondary transfer device 16 is provided on the belt driving roller 11 side of the intermediate transfer belt 10, and an intermediate transfer belt cleaning device 17 is provided on the driven roller 13 side of the intermediate transfer belt 10.

  Although not shown, the image forming apparatus 1 in this example records, for example, paper or the like on the upstream side in the recording material conveyance direction from the secondary transfer apparatus 16 in the same manner as a conventional general image forming apparatus that performs secondary transfer. A recording material storage device for storing the material, and a registration roller pair for conveying and supplying the recording material from the recording material storage device to the secondary transfer device 16. Similarly, the image forming apparatus 1 includes a fixing device and a paper discharge tray on the downstream side in the recording material conveyance direction from the secondary transfer device 16.

Each of the charging devices 3Y, 3M, 3C, 3K is composed of a charging member such as a charging roller. A bias having the same polarity as the charging polarity of the liquid developer is applied to each charging device 3Y, 3M, 3C, 3K from a power supply device (not shown). Each of the charging devices 3Y, 3M, 3C, 3K charges the corresponding photoreceptors 2Y, 2M, 2C, 2K.

  FIG. 2 is a perspective view of the exposure apparatus, and FIG. 3 is a diagram schematically showing a cross section of the exposure apparatus. Each of the exposure apparatuses 4Y, 4M, 4C, 4K has the same configuration. Therefore, in the following description of the exposure apparatus, the symbols Y, M, C, and K of the exposure apparatuses 4Y, 4M, 4C, and 4K are deleted as shown in FIGS.

  2 and 3, the exposure apparatus 4 includes a light emitting element array having a lens array 4a and a plurality of light emitting elements 4b. A predetermined number of these lens arrays 4a and light emitting elements 4b are linearly arranged in the main scanning direction, which is the first direction along the longitudinal direction of the photoconductor 2 (the axial direction of the photoconductor 2). Further, the columns of the lens array 4a and the light emitting elements 4b are orthogonal to or substantially orthogonal to the first direction, respectively, by a predetermined number of columns (three columns in the illustrated example; these three columns will be described below). Two-dimensionally arranged in a matrix in the sub-scanning direction (moving direction of the photoreceptor 2), which is the second direction. In this case, the lens array 4a and the light emitting element 4b are arranged in a long shape in the main scanning direction. The number of light emitting elements 4b is set to be equal to or greater than the number of lens arrays 4a.

  Each lens array 4a and each light emitting element 4b are supported by a light emitting element support member 4d (corresponding to a support member of the present invention) extending along the main scanning direction. In that case, a predetermined number of lens arrays 4a are arranged adjacent to each other, and the light emitting elements 4b are arranged corresponding to the three lens arrays 4a to form a light emitting element group. Each lens array 4a, each light emitting element 4b, and light emitting element support member 4d arranged in parallel in these three rows constitute a line head in the exposure apparatus 4 of this example.

  In FIG. 3, each column of the lens array 4a and the light emitting element 4b is arranged so that the first column at the right end is adjacent to the second column at the center and the third column at the left side is adjacent to the second column at the center. ing. For each light emitting element 4b of the light emitting element group, for example, a semiconductor laser, LED, or organic EL can be used. Then, the light emitted from each light emitting element 4b is irradiated onto the surface of the photosensitive member 2 with the focal point being brought into focus through the corresponding lens array 4a. In that case, the light from each light emitting element 4b is irradiated on the surface of the photosensitive member 2 with a beam spot 4e which is an imageable range. Thereby, printing (image writing) is performed on the photosensitive member 2, and an electrostatic latent image is formed on the surface of the photosensitive member 2.

For example, when a horizontal line (a straight line extending in the axial direction of the photosensitive member 2) is printed on the photosensitive member 2 by each light emitting element 4b, the photosensitive member 2 is irradiated with a beam spot 4e by lighting of each light emitting element 4b in the first row. Thus, the first beam spot row 4f is formed on the photoreceptor 2 as shown in FIG. At this time, in each beam spot 4e, the potential of the photosensitive member 2 drops due to light irradiation from the light emitting element 4b, and an image 4g is formed. Since the light is weak in the region other than the image 4g in the beam spot 4e, the potential of the photoconductor 2 does not drop and no image is formed. This imaging 4g, electrostatic latent image 4g ₁ horizontal line image is printed on the surface of the photosensitive member 2.

Similarly, the second and third beam spot rows 4j and 4n are respectively formed on the photosensitive member 2 by being irradiated with the beam spots 4h and 4i by the light emitting elements 4b in the second and third rows, respectively. . Then, electrostatic latent images 4o ₁ and 4p ₁ of horizontal line images are printed on the surface of the photosensitive member 2 by imaging 4o and 4p formed in the beam spots 4h and 4i, respectively.

The light emitting elements 4b in the first to third columns are arranged so that the electrostatic latent images 4g ₁ , 4o ₁ , 4p ₁ of the horizontal line images by the light emitting elements 4b in the respective columns become horizontal electrostatic latent images 51. Each is lit according to the rotational speed of the photoreceptor 2. That is, the photosensitive member 2 is in the direction of arrow α (counterclockwise in FIG. 3).
, Each light emitting element 4b in the first row is turned on first, then each light emitting element 4b in the second row is turned on according to the rotation speed of the photosensitive member 2, and finally each light emitting element in the third row is turned on. The elements 4b are turned on according to the rotation speed of the photosensitive member 2, respectively. In that case, if the rotation of the photosensitive member 2 is uneven, the electrostatic latent image does not become a horizontal straight line but becomes a disturbed electrostatic latent image 51 '. Therefore, it is required that the rotation of the photoreceptor 2 is as uneven as possible.

  Each of the developing devices 5Y, 5M, 5C, and 5K includes a developer supply unit 18Y, 18M, 18C, and 18K, a developing roller 19Y, 19M, 19C, and 19K, and a compaction roller 20Y, 20M, 20C, and 20K. Roller cleaners 21Y, 21M, 21C, and 21K, and developing roller cleaner recovery liquid storage units 22Y, 22M, 22C, and 22K are provided.

  The developer supply units 18Y, 18M, 18C, and 18K respectively include developer containers 24Y, 24M, and 24K that store liquid developers 23Y, 23M, 23C, and 23K including toner particles that are solid toner and a nonvolatile liquid carrier. 24C, 24K, developer pumping rollers 25Y, 25M, 25C, 25K, anilox rollers 26Y, 26M, 26C, 26K, and developer regulating blades 27Y, 27M, 27C, 27K.

  The liquid developers 23Y, 23M, 23C, and 23K accommodated in the developer containers 24Y, 24M, 24C, and 24K are all non-volatile liquid carriers (for example, having a viscosity of 30 to 2000 mPa · s). Solid toner (toner particles) (charged during image formation) is dispersed in an insulating oil such as silicone oil and mineral oil that does not release the charge of the toner. As the toner particles, for example, particles having an average particle diameter of 1 μm in which a colorant such as a known pigment is dispersed in a known thermoplastic resin used for the toner can be used.

  The developer pumping rollers 25Y, 25M, 25C, and 25K pump the liquid developers 23Y, 23M, 23C, and 23K in the developer containers 24Y, 24M, 24C, and 24K, respectively, and the anilox rollers 26Y, 26M, and 26C, respectively. , 26K. Each of the developer pumping rollers 25Y, 25M, 25C, and 25K is configured to rotate clockwise as indicated by an arrow in FIG. Each of the anilox rollers 26Y, 26M, 26C, and 26K is a roller that is a cylindrical member and has a fine and uniform spiral groove formed on the surface thereof. For example, the groove pitch is set to about 170 μm and the groove depth is set to about 30 μm. Of course, the dimension of the groove is not limited to these values. Each of the anilox rollers 26Y, 26M, 26C, and 26K is configured to rotate counterclockwise as indicated by an arrow in FIG. 1 in the same direction as each of the developing rollers 19Y, 19M, 19C, and 19K. The anilox rollers 26Y, 26M, 26C, and 26K can be rotated together with the developing rollers 19Y, 19M, 19C, and 19K. That is, the rotation direction of the anilox rollers 26Y, 26M, 26C, and 26K is not limited and is arbitrary.

  The developer regulating blades 27Y, 27M, 27C, and 27K are provided in contact with the surfaces of the anilox rollers 26Y, 26M, 26C, and 26K, respectively. These developer regulating blades 27Y, 27M, 27C, and 27K are respectively rubber portions made of urethane rubber and the like that are in contact with the surfaces of the anilox rollers 26Y, 26M, 26C, and 26K, and metals that support the rubber portions. It is comprised from the board. Each of the developer regulating blades 27Y, 27M, 27C, and 27K scrapes and removes the liquid developer that adheres to the surfaces other than the groove portions of the anilox rollers 26Y, 26M, 26C, and 26K. Accordingly, each of the anilox rollers 26Y, 26M, 26C, and 26K is configured to supply only the liquid developer adhering in the groove portions to the developing rollers 19Y, 19M, 19C, and 19K.

Each of the developing rollers 19Y, 19M, 19C, and 19K is a cylindrical member having a width of, for example, about 320 mm. For example, an elastic body such as conductive urethane rubber and a resin layer or rubber are provided on the outer periphery of a metal shaft such as iron. With a layer. These developing rollers 19Y, 19M, 19C, and 19K are in contact with the photosensitive members 2Y, 2M, 2C, and 2K, respectively, and are rotated counterclockwise as indicated by arrows in FIG.

  Each of the compaction rollers 20Y, 20M, 20C, and 20K is configured to rotate clockwise as indicated by an arrow in FIG. Each of the compaction rollers 20Y, 20M, 20C, and 20K is applied with a voltage to charge the corresponding developing rollers 19Y, 19M, 19C, and 19K. In that case, the voltage applied to each compaction roller 20Y, 20M, 20C, 20K is set to a direct voltage (DC). The applied voltage to each of the compaction rollers 20Y, 20M, 20C, and 20K can be set to a voltage obtained by superimposing an AC voltage (AC) on a DC voltage (DC). The compaction rollers 20Y, 20M may be applied to the compaction rollers 20Y, 20M, 20C, and 20K, whether they are direct current voltages alone or superimposed voltages of direct current voltages (DC) and alternating current voltages (AC). , 20C, 20K and the developing rollers 19Y, 19M, 19C, 19K are set to be larger than the discharge start voltage for starting discharge according to Paschen's law.

  When the developing rollers 19Y, 19M, 19C, and 19K are charged by the compaction rollers 20Y, 20M, 20C, and 20K, the liquid developers 23Y, 23M, 23C, and 23K on the developing rollers 19Y, 19M, 19C, and 19K, respectively. Is pressed against the developing rollers 19Y, 19M, 19C, and 19K.

  By the way, the electrical resistance of each compaction roller 20Y, 20M, 20C, 20K is relatively important. That is, when the resistance of each of the compaction rollers 20Y, 20M, 20C, and 20K is low, spark discharge occurs, and each of the developing rollers 19Y, 19M, 19C, and 19K, each of the compaction rollers 20Y, 20M, 20C, and 20K, and each of the liquids. The developers 23Y, 23M, 23C, and 23K are damaged. Therefore, each compaction roller 20Y, 20M, 20C, and 20K has an actual resistance value of Log 7Ω or more, and good compaction of each liquid developer 23Y, 23M, 23C, and 23K is uniform without causing such damage. It is preferable in carrying out.

  Further, although not clearly shown in FIG. 1, each of the compaction rollers 20Y, 20M, 20C, and 20K has an outer peripheral surface corresponding to the outer peripheral surface of each of the developing rollers 19Y, 19M, 19C, and 19K. They are arranged with a predetermined gap (μm). In this case, these gaps are formed on the outer peripheral surfaces of the developing rollers 19Y, 19M, 19C, and 19K by the liquid developers 23Y, 23M, 23C, and 23K supplied from the anilox rollers 26Y, 26M, 26C, and 26K. It is set larger than the film thickness (μm) of the developer layer. Accordingly, the compaction rollers 20Y, 20M, 20C, and 20K perform non-contact compaction on the liquid developers 23Y, 23M, 23C, and 23K on the development rollers 19Y, 19M, 19C, and 19K.

The compaction rollers 20Y, 20M, 20C, and 20K are provided with compaction roller cleaner blades 28Y, 28M, 28C, and 28K, and compaction roller cleaner recovery liquid storage portions 29Y, 29M, 29C, and 29K, respectively. These compaction roller cleaner blades 28Y, 28M, 28C, and 28K are made of, for example, rubber that contacts the surfaces of the corresponding compaction rollers 20Y, 20M, 20C, and 20K, and remain on the compaction rollers 20Y, 20M, 20C, and 20K. The developer to be removed is scraped off and removed. Further, each of the compaction roller cleaner recovered liquid storage portions 29Y, 29M, 29C, and 29K is respectively scraped off from the compaction rollers 20Y, 20M, 20C, and 20K by the compaction roller cleaner blades 28Y, 28M, 28C, and 28K. It is comprised from containers, such as a tank which stores.

  Further, each of the developing roller cleaners 21Y, 21M, 21C, and 21K is made of, for example, rubber or the like that contacts the surface of the corresponding developing roller 19Y, 19M, 19C, or 19K, and is connected to the developing rollers 19Y, 19M, 19C, and 19K. The residual developer is scraped off and removed. Further, the developing roller cleaner collection liquid storage units 22Y, 22M, 22C, and 22K respectively remove the developer scraped off from the developing rollers 19Y, 19M, 19C, and 19K by the developing roller cleaners 21Y, 21M, 21C, and 21K. It is comprised from containers, such as a tank to store.

  Further, the image forming apparatus 1 of this example includes developer supply devices 30Y, 30M, 30C, and 30K that supply the liquid developers 23Y, 23M, 23C, and 23K to the developer containers 24Y, 24M, 24C, and 24K, respectively. Yes. These developer replenishing devices 30Y, 30M, 30C, and 30K include toner tanks 31Y, 31M, 31C, and 31K, carrier tanks 32Y, 32M, 32C, and 32K, and stirring devices 33Y, 33M, 33C, and 33K, respectively. I have.

  The toner tanks 31Y, 31M, 31C, and 31K store high-concentration liquid toners 34Y, 34M, 34C, and 34K that contain solid toner, respectively. The carrier tanks 32Y, 32M, 32C, and 32K store liquid carriers (carrier oils) 35Y, 35M, 35C, and 35K, respectively. Further, the stirrers 33Y, 33M, 33C, and 33K include a predetermined amount of the high-concentration liquid toners 34Y, 34M, 34C, and 34K from the toner tanks 31Y, 31M, 31C, and 31K and the carrier tanks 32Y, 32M, and 33K, respectively. A predetermined amount of each liquid carrier 35Y, 35M, 35C, 35K from 32C, 32K is supplied.

  The stirrers 33Y, 33M, 33C, and 33K mix and stir the supplied high-concentration liquid toners 34Y, 34M, 34C, and 34K and the liquid carriers 35Y, 35M, 35C, and 35K, respectively, and develop them. Liquid developers 23Y, 23M, 23C, and 23K used in the apparatuses 5Y, 5M, 5C, and 5K are prepared. The liquid developers 23Y, 23M, 23C, and 23K respectively produced by the stirring devices 33Y, 33M, 33C, and 33K are supplied to the developer containers 24Y, 24M, 24C, and 24K, respectively.

  Each photoconductor squeeze device 6Y, 6M, 6C, 6K includes squeeze rollers 36Y, 36M, 36C, 36K, squeeze roller cleaners 37Y, 37M, 37C, 37K, and squeeze roller cleaner recovery liquid storage containers 38Y, 38M, 38C, 38K. The squeeze rollers 36Y, 36M, 36C and 36K are respectively connected to the photosensitive members 2Y, 2Y, and the contact portions (nip portions) between the photosensitive members 2Y, 2M, 2C and 2K and the developing rollers 19Y, 19M, 19C and 19K. It is installed on the downstream side in the rotational direction of 2M, 2C, 2K. These squeeze rollers 36Y, 36M, 36C, and 36K are rotated in the opposite direction (counterclockwise in FIG. 1) to the respective photoreceptors 2Y, 2M, 2C, and 2K, so that the respective photoreceptors 2Y, 2M, and The liquid carriers 35Y, 35M, 35C, and 35K on 2C and 2K are removed.

As each of the squeeze rollers 36Y, 36M, 36C, and 36K, an elastic roller in which an elastic member such as conductive urethane rubber and a fluororesin surface layer are arranged on the surface of a metal core is suitable. Each of the squeeze roller cleaners 37Y, 37M, 37C, and 37K is made of an elastic body such as rubber and is in contact with the surface of the corresponding squeeze roller 36Y, 36M, 36C, or 36K. The liquid carriers 35Y, 35M, 35C and 35K remaining on 36M, 36C and 36K are scraped off and removed. Further, the squeeze roller cleaner recovery liquid storage containers 38Y, 38M, 38C, and 38K are containers such as tanks that store the developer scraped off by the corresponding squeeze roller cleaners 37Y, 37M, 37C, and 37K.

Each of the primary transfer devices 7Y, 7M, 7C, and 7K includes backup rollers 39Y, 39M, 39C, and 39K for primary transfer that bring the intermediate transfer belt 10 into contact with the photoreceptors 2Y, 2M, 2C, and 2K, respectively. Yes. Each of the backup rollers 39Y, 39M, 39C, and 39K is applied with, for example, about −200 V having a polarity opposite to the charged polarity of the toner particles, so that each color toner image (liquid developer) on each of the photoreceptors 2Y, 2M, 2C, and 2K. Image) is primarily transferred to the intermediate transfer belt 10.
Further, the static eliminators 8Y, 8M, 8C, and 8K remove charges remaining on the photoreceptors 2Y, 2M, 2C, and 2K after the primary transfer, respectively.

  Each of the intermediate transfer belt squeeze devices 15Y, 15M, 15C, and 15K includes an intermediate transfer belt squeeze roller 40Y, 40M, 40C, and 40K, an intermediate transfer belt squeeze roller cleaner 41Y, 41M, 41C, and 41K, and an intermediate transfer belt squeeze, respectively. Roller cleaner recovery liquid storage containers 42Y, 42C, 42K, and 42K are provided. Each of the intermediate transfer belt squeeze rollers 40Y, 40M, 40C, and 40K collects the corresponding color liquid carriers 35Y, 35M, 35C, and 35K on the intermediate transfer belt 10, respectively. The intermediate transfer belt squeeze roller cleaners 41Y, 41M, 41C, and 41K scrape the collected liquid carriers 35Y, 35M, 35C, and 35K on the intermediate transfer belt squeeze rollers 40Y, 40M, 40C, and 40K, respectively. It is. These intermediate transfer belt squeeze roller cleaners 41Y, 41M, 41C, and 41K are each made of an elastic material such as rubber, like the squeeze roller cleaners 37Y, 37M, 37C, and 37K. Further, the intermediate transfer belt squeeze roller cleaner recovery liquid storage containers 42M, 42C, 42K, and 42K are liquid carriers 35Y, 35M, 35C, and 35K scraped by the intermediate transfer belt squeeze roller cleaners 41Y, 41M, 41C, and 41K, respectively. Is collected and stored.

  The secondary transfer device 16 includes a pair of secondary transfer rollers arranged at a predetermined interval along the recording material moving direction. Of these pair of secondary transfer rollers, the secondary transfer roller disposed upstream in the moving direction of the recording material is the upstream secondary transfer roller 43. The upstream secondary transfer roller 43 can be brought into pressure contact with the belt driving roller 11 via the intermediate transfer belt 10. Of the pair of secondary transfer rollers, the secondary transfer roller disposed on the downstream side in the moving direction of the recording material is the downstream secondary transfer roller 44. The downstream secondary transfer roller 44 can be brought into pressure contact with the driven roller 12 via the intermediate transfer belt 10. That is, the upper and downstream secondary transfer rollers 43 and 44 respectively contact the recording material against the intermediate transfer belt 10 that is hung on the belt driving roller 11 and the driven roller 12, thereby A color toner image (liquid developer image) obtained by combining the toner images of the respective colors is secondarily transferred onto a recording material.

In that case, the belt driving roller 11 and the driven roller 12 also function as backup rollers for the secondary transfer rollers 43 and 44 during the secondary transfer, respectively. That is, the belt drive roller 11 is also used as an upstream backup roller disposed in the secondary transfer device 16 on the upstream side of the driven roller 12 in the moving direction of the recording material. The driven roller 12 is also used as a downstream backup roller disposed downstream of the belt driving roller 11 in the moving direction of the recording material in the secondary transfer device 16.
Further, the load with which the upstream side secondary transfer roller 43 is pressed against the belt driving roller 11 during the secondary transfer is set to be larger than the load with which the downstream side secondary transfer roller 44 is pressed against the driven roller 12.

Accordingly, the recording material conveyed to the secondary transfer device 16 is moved from the pressure contact start position (nip start position) between the upstream side secondary transfer roller 43 and the belt drive roller 11 to the downstream side secondary transfer roller 44 and the driven roller 12. Is in close contact with the intermediate transfer belt 10 in a predetermined movement region of the recording material up to the pressure contact end position (nip end position). As a result, the full-color toner image on the intermediate transfer belt 10 is secondarily transferred to the recording material in close contact with the intermediate transfer belt for a predetermined time, so that good secondary transfer is performed.

  Further, the hardness of at least the surface layer portion of the upstream side secondary transfer roller 43 is smaller (softer) than the hardness of at least the surface layer portion of the belt driving roller 11. Therefore, as shown in FIG. 2, when the upstream secondary transfer roller 43 is pressed against the belt driving roller 11 via the intermediate transfer belt 10 during the secondary transfer, the pressure contact portion (nip portion) of the upstream secondary transfer roller 43 ) Is slightly recessed in an arc.

  On the other hand, the diameter of the downstream side secondary transfer roller 44 is set smaller than the diameter of the driven roller 12. Further, the hardness of at least the surface layer portion of the downstream side secondary transfer roller 44 is larger (harder) than the hardness of at least the surface layer portion of the driven roller 12. Therefore, as shown in FIG. 2, when the secondary transfer roller 44 on the downstream side is pressed against the driven roller 12 via the intermediate transfer belt 10 during the secondary transfer, the pressure contact portion (nip portion) of the driven roller 12 is slightly arcuate. It is supposed to dent.

  As a result, the sheet-like recording material is effectively brought into close contact with the intermediate transfer belt 10 in the predetermined movement region of the recording material described above to perform secondary transfer more efficiently, and the downstream side secondary transfer roller 44 and After passing through the pressure contact position with the driven roller 12, the intermediate transfer belt 10 is easily peeled off. In this case, since the recesses of the upstream secondary transfer roller 43 and the driven roller 12 are relatively small, the recording material is only slightly curved at each pressure contact position of each roller. Therefore, the recording material can be satisfactorily held at each press contact position.

  Further, the secondary transfer device 16 includes secondary transfer roller cleaners 45 and 46 and secondary transfer roller cleaner recovery liquid storage containers 47 and 48 for the pair of secondary transfer rollers 43 and 44, respectively. Each of the secondary transfer roller cleaners 45 and 46 is made of an elastic body such as rubber similarly to the squeeze roller cleaners 37Y, 37M, 37C, and 37K. The secondary transfer roller cleaners 45 and 46 are in contact with the secondary transfer rollers 43 and 44, respectively, and scrape off the developer remaining on the surfaces of the secondary transfer rollers 43 and 44 after the secondary transfer. Remove. The secondary transfer roller cleaner collection liquid storage containers 47 and 48 collect and store the developer scraped off from the secondary transfer rollers 43 and 44 by the secondary transfer roller cleaners 45 and 46, respectively.

  The intermediate transfer belt cleaning device 17 includes an intermediate transfer belt cleaner 49 and an intermediate transfer belt cleaner recovery liquid storage container 50. The intermediate transfer belt cleaner 49 is in contact with the intermediate transfer belt 10 and scrapes off and removes the developer remaining on the surface of the intermediate transfer belt 10 after the secondary transfer. In that case, the driven roller 13 also functions as a backup roller at the time of cleaning the intermediate transfer belt. The intermediate transfer belt cleaner 49 is made of an elastic body such as rubber. The intermediate transfer belt cleaner recovery liquid storage container 50 collects and stores the developer scraped off from the intermediate transfer belt 10 by the intermediate transfer belt cleaner 49.

  In the image forming apparatus 1 of this example configured as described above, when the image forming operation is started, the photoreceptors 2Y, 2M, 2C, and 2K are uniformed by the charging devices 3Y, 3M, 3C, and 3K, respectively. Charged. Next, an electrostatic latent image of each color is formed on each photoreceptor 2Y, 2M, 2C, 2K by each exposure device 4Y, 4M, 4C, 4K.

In the yellow Y developing device 5Y, the yellow Y liquid developer 23Y is pumped up to the anilox roller 26Y by the developer pumping roller 25Y. An appropriate amount of the liquid developer 23Y attached to the anilox roller 26Y is attached to the groove of the anilox roller 26Y by the developer regulating blade 27Y. The liquid developer 23Y in the groove of the anilox roller 26Y is supplied to the developing roller 19Y. Further, the liquid developer 23Y on the developing roller 19Y is pressed against the developing roller 19Y by non-contact compaction by the compaction roller 20Y. In this state, the liquid developer 23Y on the developing roller 19Y is conveyed toward the photoreceptor 2Y by the rotation of the developing roller 19Y.

  The carrier 35Y remaining on the compaction roller 20Y after the non-contact compaction by the compaction roller 20Y is completed is removed from the compaction roller 20Y by the compaction roller cleaner blade 28Y.

  The electrostatic latent image formed on the yellow Y photoreceptor 2Y is developed with the yellow Y liquid developer 23Y in the developing device 5Y, and a yellow Y liquid developer image is formed on the photoreceptor 2Y. The developer remaining on the developing roller 19Y after development is removed from the developing roller 19Y by the developing roller cleaner 21Y. The yellow Y liquid developer image on the photoreceptor 2Y is collected by the squeeze roller 36Y from the liquid carrier 35Y on the photoreceptor 2Y to form a yellow Y toner image. Further, the yellow Y toner image is transferred to the intermediate transfer belt 10 by the primary transfer device 7Y. The yellow Y toner image on the intermediate transfer belt 10 is conveyed toward the primary transfer device 7M of magenta M while the liquid carrier 35Y on the intermediate transfer belt 10 is collected by the intermediate transfer belt squeeze roller 40Y.

  Next, the electrostatic latent image formed on the photoconductor 2M of magenta M is developed in the developing device 5M with the magenta M liquid developer conveyed in the same manner as in the case of yellow Y, and the magenta M is developed on the photoconductor 2M. The liquid developer image is formed. At this time, the carrier 35M remaining on the compaction roller 20M after the non-contact compaction by the compaction roller 20M is removed from the compaction roller 20M by the compaction roller cleaner blade 28M. Further, the developer remaining on the developing roller 19M after the development is completed is removed from the developing roller 19M by the developing roller cleaner 21M.

  The liquid developer image of magenta M on the photoreceptor 2M is recovered as a toner image of magenta M by collecting the liquid carrier 35M on the photoreceptor 2M by the squeeze roller 36M. The toner image of magenta M is transferred to the primary transfer device 7M. The yellow Y toner image is superimposed on the intermediate transfer belt 10 and transferred. Similarly, the color-superposed yellow Y and magenta M toner images are conveyed toward the primary transfer device 7C of cyan C while the liquid carrier 35M on the intermediate transfer belt 10 is collected by the intermediate transfer belt squeeze roller 40M. The In the same manner, a cyan toner image and a black toner image are sequentially superimposed and transferred onto the intermediate transfer belt 10 to form a full-color toner image on the intermediate transfer belt 10.

  Next, the secondary transfer device 16 secondarily transfers the color toner image on the intermediate transfer belt 10 onto the transfer surface of a recording material such as paper. At this time, the recording material conveyed to the secondary transfer device 16 is moved from the pressure contact start position (nip start position) between the belt drive roller 11 and the upstream side secondary transfer roller 43 to the driven roller 12 and the downstream side secondary transfer roller. 44 is in close contact with the intermediate transfer belt 10 in a predetermined movement region of the recording material up to the press-contact end position (nip end position). That is, the recording material is in close contact with the intermediate transfer belt 10 even in the intermediate transfer belt 10 that is not located between the nip positions on the upstream and downstream sides. As a result, the full-color toner image on the intermediate transfer belt 10 is secondarily transferred to the recording material in close contact with the intermediate transfer belt 10 over a predetermined time, so that good secondary transfer is performed.

In addition, as described above, the upstream side secondary transfer roller 43 is recessed at the nip position by the pressure contact with the belt driving roller 11, so that the recording material passing through the nip position is urged toward the intermediate transfer belt 10. Therefore, the recording material that has passed through the nip position is effectively brought into close contact with the intermediate transfer belt 10. Thereby, a better secondary transfer is performed. Further, since the pressure contact force of the upstream side secondary transfer roller 43 to the belt driving roller 11 is larger than the pressure contact force of the downstream side secondary transfer roller 43 to the driven roller 12, recording is performed between these pressure contact positions (nip positions). The material is difficult to peel from the intermediate transfer belt 10. Therefore, even better secondary transfer is performed.

  Further, the diameter of the downstream secondary transfer roller 44 is set smaller than the diameter of the driven roller 12, and the driven roller 12 is recessed at the nip position by the pressure contact with the downstream secondary transfer roller 44 as described above. The recording material that has passed the nip position is urged in a direction away from the intermediate transfer belt 10. As a result, the secondary transfer onto the recording material is further improved, and the recording material is easily peeled off from the intermediate transfer belt 10 after passing the pressure contact position between the downstream secondary transfer roller 44 and the driven roller 12. become.

  The liquid developer remaining on the upstream and downstream secondary transfer rollers 43 and 44 after the secondary transfer is scraped off by the secondary transfer roller cleaners 45 and 46, respectively, and removed from the rollers 43 and 44. The removed liquid developer is recovered and stored in each of the secondary transfer roller cleaner recovery liquid storage containers 47 and 48, respectively.

  The color toner image transferred onto the recording material is fixed by a fixing device (not shown) as in the prior art. Further, the recording material on which the full-color fixed image is formed is conveyed to the paper discharge tray, and the color image forming operation is completed.

  By the way, in the exposure apparatus 4 of this example, as shown in FIG. 2, the light emitting element support member 4d has two first and second exposure position adjusting devices 52 and 53 (corresponding to the exposure position adjusting mechanism of the present invention) at both ends thereof. ) Is supported. These first and second exposure position adjusting devices 52 and 53 have the same configuration and are supported by an apparatus main body (not shown).

  FIG. 5 schematically shows the exposure position adjusting device, and is a cross-sectional view taken along line VV in FIG. FIG. 5 shows one first exposure position adjusting device 52, but the other second exposure position adjusting device 53 is exactly the same as the configuration of the first exposure position adjusting device 52. The components of the first exposure position adjusting device 52 are indicated by reference numerals with parentheses, and the illustration is omitted. In the description of the following specification, parentheses are not used for the reference numerals of the constituent elements of the second exposure position adjusting device 53.

As shown in FIG. 5, the first and second exposure position adjusting devices 52 and 53 respectively include lens arrays 4a ₁ , 4a ₂ , 4a ₃ arranged in parallel in the width direction of the light emitting element support member 4d and light emission. Elements 4b ₁ , 4b ₂ and 4b ₃ are provided. Each of the first and second exposure position adjusting devices 52, 53 includes a U-shaped exposure device support member 52a, 53a, elastic back plates 52b, 53b, and first to third position adjusting mechanisms 52c, 53c; 53d; 52e, 53e. The first and second position adjustment mechanisms 52c, 53c; 52d, 53d are configured identically to each other.
The exposure apparatus support members 52a and 53a are side views including upper bases 52a ₁ and 53a ₁ and side walls 52a ₂ , 53a ₂ ; 52a ₃ and 53a ₃ erected on both side edges of the upper bases 52a ₁ and 53a _1. It is formed in a U shape. The exposure apparatus support members 52a and 53a extend in the sub-scanning direction and are fixed to the apparatus main body.

The elastic back plates 52b and 53b are made of an elastic material such as rubber, and the exposure apparatus support members 52a and 53a and the light emitting element support member are located at the center position in the width direction of the exposure apparatus support members 52a and 53a (sub-scanning direction of the photoreceptor 2). 4d. The light emitting element support member 4d is elastically supported via the elastic back plates 52b and 53b at the center position in the width direction of the exposure apparatus support members 52a and 53a.

The first position adjusting mechanisms 52c and 53c include first position adjusting screws 52c ₁ and 53c ₁ . The first position adjusting screws 52c ₁ and 53c ₁ are screwed to one end side of the light emitting element support member 4d and penetrate the light emitting element support member 4d in the vertical direction in FIG. At the lower ends of the first position adjusting screws 52c ₁ and 53c ₁ , hemispherical lubricating members 52c ₂ and 53c ₂ made of, for example, resin having lubricity are fixed. The spherical surfaces of the lubricating members 52c ₂ and 53c ₂ are in contact with the outer peripheral surface of the non-image portion of the photoreceptor 2.

The second position adjusting mechanisms 52d and 53d include second position adjusting screws 52d ₁ and 53d ₁ . The second position adjusting screws 52d ₁ and 53d ₁ are screwed to the other end side of the light emitting element support member 4d at positions symmetrical with the vertical center lines of the elastic back plates 52b and 53b to support the light emitting element. The member 4d is vertically penetrated in FIG. Semi-spherical lubricating members 52d ₂ and 53d ₂ made of, for example, a resin having lubricity are fixed to the lower ends of the second position adjusting screws 52d ₁ and 53d ₁ . The lubrication members 52d ₂ and 53d ₂ are also in contact with the outer peripheral surface of the non-image portion of the photosensitive member 2 at the spherical portion. Accordingly, the lens arrays 4a ₁ , 4a ₂ , 4a ₃ and the light emitting elements 4b ₁ , 4b ₂ , 4b ₃ are supported on the outer peripheral surface of the non-image portion of the photosensitive member 2 at four points in the longitudinal direction. The

The third position adjusting mechanisms 52e and 53e include third position adjusting screws 52e ₁ and 53e ₁ . The third position adjusting screws 52e ₁ and 53e ₁ are arranged so that _one of the side walls 52a ₃ and 53a ₃ of the exposure apparatus supporting member 52a extends in the left-right direction (vertical direction and third position adjusting mechanisms 52e and 53e) in FIG. (Perpendicular direction). The left ends of the third position adjusting screws 52e ₁ and 53e ₁ are in contact with one side edge surface of the light emitting element support member 4d. Further, elastic members 52e ₂ and 53e ₂ made of rubber or the like are fixed to the other side edge surface of the light emitting element support member 4d. The elastic members 52e ₂ and 53e ₂ are in contact with the other side walls 52a ₂ and 53a ₂ of the exposure apparatus support members 52a and 53a.

Then, the first and second position adjusting screws 52c ₁ , 53c ₁ ; 52d ₁ , 53d ₁ are rotated in the directions of arrows β, β ′ and γ, γ ′, respectively. Then, the first and second position adjusting screws 52c ₁ , 53c ₁ ; 52d ₁ , 53d ₁ move relative to the light emitting element support member 4d toward the photoconductor 2 or away from the photoconductor 2. Move relative to In that case, the first and second position adjusting screws 52c _1, 53c _1; during rotation of 52 d _1, 53d _1, lubricating members 52c _2, 53c _2; 52 d _2, the first and second position adjusting screw 52c by 53d _{2 1} , 53c ₁ ; friction between 52d ₁ , 53d ₁ and the photosensitive member 2 is reduced. The exposure apparatus 4 moves the arrows δ, δ ′ and ε. With respect to the photosensitive member 2 by relative movement of the first and second position adjusting screws 52c ₁ , 53c ₁ ; 52d ₁ , 53d ₁ with respect to the light emitting element support member 4d. Moving in the ε ′ direction, the distance between the photosensitive member 2 and the exposure device 4 is adjusted. That is, the exposure position of the light emitting elements 4b in the first to third rows to the photosensitive member 2 is adjusted.

In this case, the first and second position adjusting screws 52c ₁ , 53c ₁ ; 52d ₁ , 53d ₁ are moved relative to the light emitting element support member 4d in the opposite directions by the same amount. Then, the light emitting element support member 4d rotates about the axis in the main scanning direction at the center position in the sub-scanning direction, which is the exposure position of each light emitting element 4b. That is, the first and second position adjusting mechanisms 52c, 53c; 52d, 53d constitute a rotary exposure position adjusting unit that adjusts the exposure position by rotating the lens array 4a and the light emitting element 4b about the axis. Yes.

Further, the first and second position adjusting screws 52c ₁ , 53c ₁ ; 52d ₁ , 53d ₁ are pressed against the photoreceptor 2 through the lubricating members 52c ₂ , 53c ₂ ;, 52d ₂ , 53d ₂ , respectively. The reaction force of the pressure contact force, that is, the photosensitive member 2 has the first and second position adjusting screws 52c ₁ , 53c ₁ ; 52d ₁ , 53d ₁
The force pushing the light emitting element support member 4d is transmitted to the elastic members 52b and 53b in the directions of the arrows ζ and ζ ′ via. Therefore, the force pushing the light emitting element support member 4d of the photosensitive member 2 is absorbed by the elastic member 52b53b elastically deforming. As a result, even if rotation unevenness occurs in the photosensitive member 2 and the force for pushing the light emitting element support member 4d of the photosensitive member 2 fluctuates, the fluctuation of this force is absorbed by the elastic members 52b and 3b. The positional deviation of the light emitting elements 4b and the lens array 4a in the directions of arrows δ and δ ′ and in the directions ε and ε ′ is suppressed.

On the other hand, the third position adjusting screws 52e ₁ and 53e ₁ are rotated in the directions of the arrows η and η ′ so as to move relative to the side walls 52a ₃ and 53a ₃ toward the exposure apparatus 4 and away from the exposure apparatus 4. Move relative to the direction. As a result, the exposure apparatus 4 (that is, the position of the lens array 4a and the light emitting element 4b) moves in the same direction as the moving direction of the third position adjusting screws 52e ₁ and 53e ₁ , and the arrows θ and θ that are the sub-scanning directions. The exposure position in the ′ direction is adjusted. That is, the third position adjustment mechanism 52e.53e moves the lens array 4a and the light emitting element 4b in the θ.θ ′ direction to adjust the exposure position in the sub-scanning direction (the first position adjustment mechanism of the present invention). 2 directional exposure position adjustment unit).

Further, the elastic members 52e ₂ and 53e ₂ fixed to the light emitting element support member 4d of the exposure apparatus 4 are brought into contact with the side walls 52a ₂ and 53a ₂ of the exposure apparatus support members 52a and 53a, so that the third position adjustment is performed. Forces from the screws 52e ₁ and 53e ₁ are transmitted in the directions of arrows ι and ι ′ to the elastic members 52e ₂ and 53e ₂ through the light emitting element support member 4d. Further, due to the rotation of the photosensitive member 2 in the direction of the arrow α, the rotational force is also increased by the lubricating members 52c ₂ , 53c ₂ ; 52d ₂ , 53d ₂ , first and second position adjusting screws 52c ₁ , 53c ₁ ; 52d ₁ , 53d ₁ , In the same manner, the light is transmitted to the elastic members 52e ₂ and 53e ₂ in the directions of arrows ι and ι ′ via the light emitting element support member 4d. Accordingly, the force pushing the light emitting element support member 4d by the rotation of the photosensitive member 2 is absorbed by elastic deformation of the elastic members 52e ₂ and 53e ₂ . As a result, even if the rotation unevenness occurs in the photosensitive member 2 and the force pushing the light emitting element support member 4d due to the rotation of the photosensitive member 2 fluctuates, the fluctuation of this force is absorbed by the elastic members 52e ₂ and 53e ₂ . Further, the positional deviation of the light emitting element 4b and the lens array 4a of the exposure apparatus 4 in the directions of the arrows θ and θ ′ is suppressed.

Next, an example of an exposure position adjustment procedure (method) in the lens array 4a and the light emitting element 4b by the first to third position adjustment mechanisms 52c, 53c; 52d, 53d; 52e, 53e will be described. Among three rows of light emitting elements 4b, firstly, the exposure position of the center of the light emitting element 4b ₂ is adjusted.

(Explanation of the exposure position adjustment procedure of the central light emitting element 4b ₂ )
In the center of the light-emitting element 4b ₂ of the exposure position adjustment procedure, first, the direction as shown in Table 1 δ, ε, θ, δ ', ε', the lower limit and the upper limit value of the adjustment amount in the theta 'is set . In Table 1, the direction of the arrow in each direction δ, ε, θ, δ ′, ε ′, θ ′ in FIG. 2 is positive.

  As shown in Table 1, the adjustment amount lower limit value in the δ direction of the first position adjustment mechanism 52c is set to −dδ, and the adjustment amount lower limit value in the ε direction of the first position adjustment mechanism 52c is set to −dε. The lower limit of the adjustment amount in the θ direction of the first position adjustment mechanism 52c is set to −dθ. Further, the adjustment amount upper limit value in the δ direction of the first position adjustment mechanism 52c is set to + dδ, the adjustment amount upper limit value in the ε direction of the first position adjustment mechanism 52c is set to + dε, and the first position adjustment mechanism 52c. The upper limit of the adjustment amount in the θ direction is set to + dθ. On the other hand, the adjustment amount lower limit value in the δ ′ direction of the second position adjustment mechanism 53c is set to −dδ ′, and the adjustment amount lower limit value in the ε ′ direction of the second position adjustment mechanism 53c is set to −dε ′. The lower limit of the adjustment amount in the θ ′ direction of the second position adjustment mechanism 53c is set to −dθ ′. Further, the adjustment amount upper limit value in the δ ′ direction of the second position adjustment mechanism 53c is set to + dδ ′, the adjustment amount upper limit value in the ε ′ direction of the second position adjustment mechanism 53c is set to + dε ′, and the second The upper limit of the adjustment amount in the θ ′ direction of the position adjustment mechanism 53c is set to + dθ ′. These adjustment amount lower limit value and adjustment amount upper limit value vary depending on the shape, specifications, use conditions, and the like of the image forming apparatus, and are indicated by symbols dθ, dε,... For generalization.

Next, as shown in Table 2, the exposure position adjustment pattern of the exposure position adjustment image that is initially printed in order to adjust the exposure position of the central light emitting element 4b ₂ is divided into four patterns A, B, C, D in this example. Is set. These patterns A, B, C, and D are different combinations of initial positions in the δ, ε, θ, δ ′, ε ′, and θ ′ directions. The combinations of these initial positions are not limited to four, and any number of combinations is possible. Further, the initial position in each direction is not limited to the position shown in Table 2, and can be arbitrarily set. Hereinafter, for the sake of convenience, description will be made according to the items described in Table 2.

First, the pattern A will be described. As shown in Table 2, δ of the first position adjusting mechanism 52c
, Ε, and θ directions are set to positions of + dδ, + dε, and + dθ, which are upper limit values of the adjustment amounts, respectively. On the other hand, the initial positions of the second position adjustment mechanism 53c in the δ ′, ε ′, and θ ′ directions are set to the positions of −dδ ′, −dε ′, and −dθ ′, which are lower limit values of the adjustment amounts, respectively. The

  Next, the pattern B will be described. As shown in Table 2, the initial positions of the first position adjustment mechanism 52c in the δ and ε directions are set to + dδ and + dε, which are upper limit values of the adjustment amounts, respectively. Further, the initial position in the θ direction of the first position adjusting mechanism 52c is set to a position of −dθ that is the lower limit value of the adjustment amount. On the other hand, the initial positions of the second position adjusting mechanism 53c in the δ ′ and ε ′ directions are set to −dδ and −dε which are lower limit values of the adjustment amounts, respectively. Further, the initial position in the θ ′ direction of the second position adjusting mechanism 53c is set to a position of + dθ ′ that is the upper limit value of the adjustment amount.

  Next, the pattern C will be described. As shown in Table 2, the initial positions of the first position adjustment mechanism 52c in the δ and ε directions are set to −dδ and −dε, which are lower limit values of the adjustment amounts, respectively. Further, the initial position in the θ direction of the first position adjusting mechanism 52c is set to a position of + dθ that is the adjustment amount upper limit value. On the other hand, initial positions in the δ ′ and ε ′ directions of the second position adjusting mechanism 53c are set to + dδ and + dε, which are upper limit values of the adjustment amounts, respectively. Further, the initial position in the θ ′ direction of the second position adjusting mechanism 53c is set to the position of −dθ ′ that is the lower limit value of the adjustment amount.

  Next, the pattern D will be described. As shown in Table 2, the initial positions of the first position adjustment mechanism 52c in the δ, ε, and θ directions are set to the positions of −dδ, −dε, and −dθ, which are lower limit values of the adjustment amounts, respectively. . On the other hand, the initial positions in the δ ′, ε ′, and θ ′ directions of the second position adjusting mechanism 53c are set to the positions of + dδ ′, + dε ′, and + dθ ′, which are the upper limit values of the adjustment amounts, respectively.

FIG. 6 is a diagram schematically showing an exposure position adjustment image initially printed. Note that the exposure position adjustment image shown in FIG. 6 is a generalized exposure position adjustment image in each of the patterns A, B, C, and D.
As shown in FIG. 6, when an exposure position adjustment image 55 is printed on a recording material (paper) 54 with each direction of the first and second position adjustment mechanisms 52c and 53c set to initial positions, this exposure position adjustment is performed. The image (exposure unit) 55 has an exposure position adjustment image range 55a that is in focus and an exposure position adjustment image range 55b that is not in focus.

  When the range 55b of the exposure position adjustment image that is not in focus is observed with a microscope, the range 55b is in a state in which the one-dot width vertical line is disturbed as shown in FIG. There are at least one of a state where the vertical lines are faint and a state where printing is not possible because the latent image is too shallow to be developed. Further, when the range 55a of the exposure position adjustment image that is in focus is observed with a microscope, a vertical line of 1 dot width appears straight in the range 55a. Therefore, by observing these states of the exposure position adjustment image with the microscope, it is determined whether the exposure position adjustment image is in focus or not.

In FIG. 6, 55c is the center in the width direction of the range of the exposure position adjustment image in focus, LL is the maximum width of the exposure position adjustment image (exposure part), and LC is the center 55c of the range in focus. And the end position of the exposure position adjustment image (exposure section) on the first first exposure position adjustment apparatus 52 side, μ is the direction in which the rotation direction of the photosensitive member 2 corresponds to the recording material 54, and ν is This is a direction corresponding to the θ direction of the first first exposure position adjusting device 52.
In such an exposure position adjustment image (exposed portion), showing the exposure adjustment position when the range the central focus of the light emitting element 4b ₂ is correct is greatest in Table 3

  First, the exposure adjustment position when the focus matching range in the pattern A is the maximum will be described. As shown in Table 3, the exposure adjustment position in the δ direction of the first position adjustment mechanism 52c is −dδ + (dδ + dδ ′) × LC / LL. The exposure adjustment position in the ε direction is −dε + (dε + dε ′) × LC / LL. Further, the exposure adjustment position in the θ direction is −dθ + (dθ + dθ ′) × LC / LL. On the other hand, the exposure adjustment position in the δ ′ direction of the second position adjustment mechanism 53c is + dδ ′ − (dδ + dδ ′) × (LL−LC) / LL. The exposure adjustment position in the ε ′ direction is + dε ′ − (dε + dε ′) × (LL−LC) / LL. Further, the exposure adjustment position in the θ ′ direction is + dθ ′ − (dθ + dθ ′) × (LL−LC) / LL.

  Next, the exposure adjustment position when the focus matching range in the pattern B is the maximum will be described. As shown in Table 3, the exposure adjustment position in the δ direction of the first position adjustment mechanism 52c is −dδ + (dδ + dδ ′) × LC / LL. The exposure adjustment position in the ε direction is −dε + (dε + dε ′) × LC / LL. Further, the exposure adjustment position in the θ direction is + dθ− (dθ + dθ ′) × LC / LL. On the other hand, the exposure adjustment position in the δ ′ direction of the second position adjustment mechanism 53c is + dδ ′ − (dδ + dδ ′) × (LL−LC) / LL. The exposure adjustment position in the ε ′ direction is + dε ′ − (dε + dε ′) × (LL−LC) / LL. Further, the exposure adjustment position in the θ ′ direction is −dθ ′ + (dθ + dθ ′) × (LL−LC) / LL.

  Further, the exposure adjustment position when the focus matching range in the pattern C is the maximum will be described. As shown in Table 3, the exposure adjustment position in the δ direction of the first position adjustment mechanism 52c is + dδ− (dδ + dδ ′) × LC / LL. The exposure adjustment position in the ε direction is + dε− (dε + dε ′) × LC / LL. Further, the exposure adjustment position in the θ direction is −dθ + (dθ + dθ ′) × LC / LL. On the other hand, the exposure adjustment position in the δ ′ direction of the second position adjustment mechanism 53c is −dδ ′ + (dδ + dδ ′) × (LL−LC) / LL. The exposure adjustment position in the ε ′ direction is −dε ′ + (dε + dε ′) × (LL−LC) / LL. Further, the exposure adjustment position in the θ ′ direction is + dθ ′ − (dθ + dθ ′) × (LL−LC) / LL.

  Further, the exposure adjustment position when the focus matching range in the pattern D is the maximum will be described. As shown in Table 3, the exposure adjustment position in the δ direction of the first position adjustment mechanism 52c is + dδ− (dδ + dδ ′) × LC / LL. The exposure adjustment position in the ε direction is + dε− (dε + dε ′) × LC / LL. Further, the exposure adjustment position in the θ direction is + dθ + (dθ + dθ ′) × LC / LL. On the other hand, the exposure adjustment position in the δ ′ direction of the second position adjustment mechanism 53c is −dδ ′ + (dδ + dδ ′) × (LL−LC) / LL. The exposure adjustment position in the ε ′ direction is −dε ′ + (dε + dε ′) × (LL−LC) / LL. Further, the exposure adjustment position in the θ ′ direction is −dθ ′ − (dθ + dθ ′) × (LL−LC) / LL.

The first and second position adjusting mechanism 52c, the direction of the exposure adjustment position of 53C is thus the patterns A, B, C, middle a focused range of the light-emitting element 4b ₂ in D is at the maximum It is adjusted to the exposure adjustment position. Thus, an exposure position of the center of the light emitting element 4b ₂ is adjusted so focus is more up. Next, the exposure positions of the light emitting elements 4b ₁ and 4b ₃ at both ends are adjusted.

(Explanation of exposure position adjustment procedure of light emitting elements 4b ₁ and 4b ₃ at both ends)
In the procedure for adjusting the exposure positions of the light emitting elements 4b ₁ and 4b ₃ at both ends, as shown in Table 4, the exposure position adjustment image to be initially printed is adjusted to adjust the exposure positions of the light emitting elements 4b ₁ and 4b ₃ at both ends. In this example, two patterns E and F are set as exposure position adjustment patterns. These patterns E and F are different combinations of initial positions in the δ, ε, δ ′, and ε ′ directions. The combinations of these initial positions are not limited to two, and any number of combinations are possible. The initial position in each direction is not limited to the position shown in Table 4, and can be set arbitrarily. Hereinafter, for the sake of convenience, description will be made according to the items described in Table 4.

  First, the pattern E will be described. As shown in Table 4, the initial positions of the first position adjusting mechanism 52c in the δ and ε directions are set to −κ and + κ, respectively. That is, both end portions of the first position adjusting mechanism 52c are initially moved by the same amount in the opposite directions in the δ and ε directions, respectively. On the other hand, the initial positions of the second position adjusting mechanism 53c in the δ ′ and ε ′ directions are set to + λ and −λ, respectively. That is, similarly, both end portions of the second position adjusting mechanism 53c are initially moved in the opposite directions by the same amount in the δ ′ and ε ′ directions, respectively. Here, κ ≦ dδ and dδ ′, whichever is smaller, and λ ≦ dδ and dδ ′, whichever is smaller.

  Next, the pattern F will be described. As shown in Table 4, the initial positions of the first position adjusting mechanism 52c in the δ and ε directions are set to + κ and −κ, respectively. That is, both end portions of the first position adjusting mechanism 52c are initially moved by the same amount in the opposite directions in the δ and ε directions, respectively. On the other hand, the initial positions of the second position adjustment mechanism 53c in the δ ′ and ε ′ directions are set to −λ and + λ, respectively. That is, similarly, both end portions of the second position adjusting mechanism 53c are initially moved in the opposite directions by the same amount in the δ ′ and ε ′ directions, respectively. Here, κ ≦ dδ and dδ ′, whichever is smaller, and λ ≦ dδ and dδ ′, whichever is smaller.

In the patterns E and F, as described above, both end portions of the first and second position adjusting mechanisms 52c and 53c are initially moved in the opposite directions by the same amount, so that the lens array 4a and the light emitting element are moved. 4b is rotated in the main scanning direction of the axis already through the adjusted central exposure adjustment position of the light-emitting element 4b ₂ as substantially the center. Thus, the adjusted central exposure adjustment position of the light-emitting element 4b ₂ is displaced is prevented. Further, since the initial positions in the θ and θ ′ directions are not set in the patterns E and F, it is possible to prevent the exposure adjustment position of the central light emitting element 4b _{2 from} being shifted.
In such patterns E and F, Table 5 shows exposure adjustment positions when the range in which the light emitting elements 4b ₁ and 4b ₃ at both ends are in focus is the maximum.

First, the exposure adjustment position when the focus matching range in the pattern E is the maximum will be described. As shown in Table 5, the exposure adjustment position in the δ direction of the first position adjustment mechanism 52c is −κ + (κ + λ) × LC / LL. The exposure adjustment position in the ε direction is + κ− (κ + λ) × LC / LL. On the other hand, the exposure adjustment position in the δ ′ direction of the second position adjustment mechanism 53c is + λ− (κ + λ) × (LL−LC) / LL. The exposure adjustment position in the ε ′ direction is −λ + (κ + λ) × (LL−LC) / LL. Even in this adjustment, the exposure adjustment position of the center light-emitting element 4b ₂ that has already been adjusted is prevented from being shifted, as described above.

Next, the exposure adjustment position when the focus matching range in the pattern F is the maximum will be described. As shown in Table 5, the exposure adjustment position in the δ direction of the first position adjustment mechanism 52c is + κ− (κ + λ) × LC / LL. The exposure adjustment position in the ε direction is −κ + (κ + λ) × LC / LL. On the other hand, the exposure adjustment position in the δ ′ direction of the second position adjustment mechanism 53c is −λ + (κ + λ) × (LL−LC) / LL. The exposure adjustment position in the ε ′ direction is + λ− (κ + λ) × (LL−LC) / LL. Even in this adjustment, the exposure adjustment position of the center light-emitting element 4b ₂ that has already been adjusted is prevented from being shifted, as described above.

The exposure adjustment positions in the respective directions of the first and second position adjustment mechanisms 52c and 53C are as described above when the focus matching ranges of the light emitting elements 4b ₁ and 4b ₃ at both ends in the patterns E and F are maximum. It is adjusted to the exposure adjustment position. As a result, the exposure positions of the light emitting elements 4b ₁ and 4b ₃ at both ends are adjusted so as to be focused to the maximum. In this way, the exposure positions of the three rows of light emitting elements 4b ₁ , 4b ₂ , 4b ₃ are adjusted so that the focus is maximized.

FIG. 7 is a flowchart illustrating a procedure for performing an exposure adjustment position by the exposure position adjustment apparatus.
As shown in FIG. 7, first, exposure position adjustment is started in step S1. Next, in step S2, the exposure apparatus 4 is set to the initial position of each pattern A, B, C, D for each pattern. Thereafter, the patterns A, printed B, C, of the center of the light-emitting element 4b ₂ only by one-dot width vertical line for each D a (sub scanning direction) image. Next, in step S3, a pattern in which the in-focus range 55a has the maximum width is selected.

Next, in step S4, the exposure position is adjusted according to the exposure adjustment position of the selected pattern among the patterns described in Table 3. In step S5, again, printing a one-dot width vertical line image due to only the center of the light emitting element 4b _2. Next, in step S6, the exposure position is adjusted again by applying Table 3 with the respective adjustment positions as new positions in the δ, ε, θ, δ ′, ε ′, and θ ′ directions.

Next, in step S7, again, printing a one-dot width vertical line image due to only the center of the light emitting element 4b _2. Next, in step S8, it is determined whether or not the width of the range 55a in which the printed 1-dot width vertical line image is in focus is substantially the maximum exposed portion width LL. If it is determined that this width is substantially the maximum exposed portion width LL, the exposure apparatus 4 is set to the initial position of the pattern E or F described in Table 4 in step S9. Thereafter, a 1-dot wide vertical line image is printed only by the light emitting elements 4b ₁ and 4b _{3 at} both ends. Next, in step S10, the exposure position is adjusted according to the exposure adjustment position of the pattern E or F described in Table 5. Next, in step S11, a 1-dot width vertical line image is printed again by only the light emitting elements 4b ₁ and 4b _{3 at} both ends.

  Next, in step S12, it is determined whether or not the width of the range 55a in which the printed 1-dot width vertical line image is in focus is substantially the maximum exposed portion width LL. If it is determined that this width is substantially the maximum exposure portion width LL, the adjustment of the exposure position is completed assuming that all the focus of the three rows of light emitting elements 4b of the exposure apparatus 4 is more optimal in step S13.

  If it is determined in step S8 or S12 that the in-focus range 55a is not approximately the maximum exposure portion width LL, the exposure apparatus 4 is discarded in step S14 and replaced with another exposure apparatus 4. . Thereafter, the process proceeds to step S1, and exposure position adjustment is started. Thereafter, the processes in steps S1 to S14 are executed again as described above.

  According to the exposure apparatus 4 of the image forming apparatus 1 of the present embodiment configured as described above, the two-dimensionally arranged lens array 4a and the two-dimensionally arranged light emitting element 4b are arranged at the exposure position of each light emitting element 4b. In addition, first and second position adjustment mechanisms 52c53c and 52d53d are provided that rotate and adjust about the axis in the main scanning direction at the center position in the sub-scanning direction. Further, a third position adjusting mechanism 52e53e) is provided for moving and adjusting the lens array 4a and the two-dimensionally arranged light emitting elements 4b in the sub-scanning direction. Thereby, the exposure position of each light emitting element 4b can be set to a focused position. Therefore, in combination with the above-described advantages of the lens array 4a, it is possible to draw a better latent image in focus on the photoconductor 2.

  In addition, since the exposure position of each light emitting element 4b can be set to a focused position, the number of exposure apparatuses 4 that fail when the exposure apparatus 4 is incorporated into the image forming apparatus 1 can be reduced. Therefore, the yield of the exposure apparatus 4 can be improved.

  Further, the lens array 4a and the light emitting element 4b are supported by the photosensitive member 2 at two points in the sub scanning direction at least one side end in the main scanning direction. Thereby, it becomes possible to make a rotation exposure position adjustment mechanism into a simple structure.

Further, according to the exposure position adjusting method of this example, first, each light emitting element 4b and each lens array 4a are moved in the sub scanning direction to adjust the center position in the sub scanning direction at each exposure position. Next, each light emitting element 4b and each lens array 4a are rotated about the axis in the main scanning direction at the center position in the sub-scanning direction at each exposure position, so that both end portions in the sub-scanning direction at each exposure position. Adjust the position. Thereby, the exposure position of each light emitting element 4b can be more easily set to a position that is more highly focused.

  In the exposure apparatus of the present invention, the lens array 4a and the light emitting element 4b can be moved and adjusted in the sub-scanning direction, and can be moved and adjusted in a direction orthogonal to both the main scanning direction and the sub-scanning direction. it can. In this case, position adjustment by rotation of the lens array 4a and the light emitting element 4b is not performed as in the above example, but the above-mentioned desired effect can be obtained and the above-described problems of the present invention are solved. be able to. However, in order to set the exposure position of each light emitting element 4b to a more highly focused position, the positions of the lens array 4a and the light emitting element 4b are moved in the sub-scanning direction and the main scanning as in the above example. It is preferable to adjust by rotation around the direction axis.

  By the way, in the image forming apparatus 1 of this example, liquid developers 23Y, 23M, 23C, and 23K are used. As shown in FIG. 13, the liquid developer 23 is obtained by dispersing the liquid toner 34 containing the solid toner (toner particles) 34a in the high-viscosity nonvolatile liquid carrier 35 as described above.

  Since the liquid carrier 35 has a high viscosity, the liquid developer 23 conveyed by the rotation of the developing roller 19 in the ω direction passes through the nip portion between the developing roller 19 and the photoreceptor 2, and then the liquid carrier 35. 35 is separated into a liquid carrier 35 ′ adhering to the developing roller 6 and a liquid carrier 35 ″ adhering to the photoreceptor 2. At this time, the liquid carrier 35 is a carrier separating portion where both liquid carriers 35 ′ and 35 ″ are separated from each other. It is pulled in the directions of arrows ρ and ρ ′ at 35a. For this reason, pulsation occurs in the separated liquid carrier 35 ″, and as shown in FIG. 14, ribs 35d in which raised portions 35b ″ and recessed portions 35c ″ exist alternately are formed on the photoreceptor 2. The rib 35d is formed by undulation in the main scanning direction, and the solid toner 34a in the liquid carrier 35 is disturbed by the rib 35d.

On the other hand, the magnitude of exposure and the latent image potential have the relationship shown in FIG. That is, the charged potential 2a of the exposed photoreceptor 2 is reduced by the exposure energy. In FIG. 15, the charging potential 2a ₁ is the charging potential of the exposed portion by 1-dot exposure, and as shown in FIG. 15, the charging potential 2a ₂ is the charging potential of the exposed portion by 2-dot exposure. In this case, the charging potential 2a ₂ of the exposed portion by 2 dot exposure is smaller than the charging potential 2a ₁ of the exposed portion by dot exposure, and the exposure potential by 2 dot exposure is larger than the exposure potential by 1 dot exposure. That is, the exposure energy of exposure of 2 dots or more obtained by superimposing 1 dot is larger than the exposure energy of 1 dot exposure. Therefore, the developing electric field between the developing device 5 and the photosensitive member 2 in the direction of the arrow ψ shown in FIG. 13 is stronger in the exposed portion of exposure of 2 dots or more than the exposed portion of 1 dot exposure.

  When the exposure focus of the light from the light emitting element 4b is deviated, that is, when the light from the light emitting element 4b is not in focus, the exposure energy is reduced, and the charged potential of the photoconductor 2 by one dot exposure becomes shallow ( It does not change greatly from the charging potential when the photosensitive member 2 is uniformly charged). Therefore, as described above, since the developing electric field in 1-dot exposure is weak, the 1-dot width vertical line image is shaken by the ribs 35d. Therefore, as shown in FIG. 16, the 1-dot width vertical line image 58 is more disturbed than the 2-dot exposure width vertical line image 59 and the 3-dot exposure width vertical line image 60.

Accordingly, the exposure apparatus 4 of the present invention that can set the exposure position of each light emitting element 4b to a focused position is applied to the exposure apparatus of the image forming apparatus 1 using the liquid developer 23, thereby developing the light emitting element 4b. A 1-dot wide vertical line image with a relatively weak electric field is also used for the rib 35d of the liquid developer 23 described above.
Disturbances due to can be suppressed. In FIG. 15, 5 a is a developing width in 1-dot width exposure, 5 b is a developing width in 2-dot width exposure, and 5 d is a developing potential of the developing roller 19.

  Next, examples and comparative examples of the exposure position adjusting device of the exposure apparatus of the present invention will be described. In Examples and Comparative Examples, the examples 1 and 2 and the comparative examples 1 and 2 were performed two by two, respectively. In each example, a 1-dot width vertical line image was printed after the exposure adjustment was completed using the exposure apparatus 4 having the three rows of light emitting elements 4b shown in FIG. At this time, the cyan C exposure device 4C of the tandem type image forming apparatus 1 using the liquid developer shown in FIG. Printing was performed. In this case, the cyan C toner image was transferred from the cyan C photoreceptor 2C to the recording material 54 via the intermediate transfer belt 10. A known amorphous silicon photoreceptor was used as the photoreceptor 2C. As the toner used, cyan C toner composed of particles having an average particle diameter of 2 μm, for example, in which cyan pigment phthalocyanine blue is dispersed in an epoxy resin which is a thermoplastic resin was used. In addition, an experiment was performed using J paper manufactured by Fuji Xerox Co., Ltd. as the record 54. The other conditions were the same as those in Examples 1 and 2 and Comparative Examples 1 and 2, except for the following. Then, by observing a 1-dot width vertical line image with a microscope and finding that the width of the in-focus range 55a is substantially the maximum exposed portion width LL, the pass is accepted, and the others are rejected. .

Example 1
In the first embodiment, using the first and second exposure position adjusting devices 52 and 53 shown in FIGS. 2 and 5, the exposure position is adjusted according to the flow of the exposure position adjustment procedure shown in FIG. Was adjusted.

(Example 2)
In the second embodiment, using the first and second exposure position adjusting devices 52 and 53 shown in FIGS. 8 and 9, the exposure position is adjusted according to the flow of the exposure position adjustment procedure shown in FIG. Was adjusted. That is, as shown in FIGS. 8 and 9, in the second embodiment, a preset value is set between the light emitting element support member 4d of the exposure apparatus 4 and the upper bases 52a ₁ and 53a ₁ of the exposure apparatus support members 52a and 53a. A predetermined number (three in the illustrated example) of rear spacers 52b 'and 53b' having a set thickness are provided. Then, the light-emitting element support member 4d is screwed to the exposure apparatus support members 52a and 53a by an adjusting screw (not shown), so that the lens array 4a ₂ located at the center in the width direction of the light-emitting element support member 4d and the photosensitive member 2 , Adjust the distance in ξ ′ direction. In FIG. 8, adjustment screws for adjusting the exposure position in the ξ and ξ ′ directions are omitted. The adjustment screws of the position adjustment mechanism for adjusting the exposure position in the ξ and ξ ′ directions are the first and second position adjustment mechanisms 52c and 53c of the first embodiment; the first and second position adjustment screws 52c ₁ and 52d of 52d and 53d, 53c ₁ ; 52d ₁ , 53d ₁ ) is used. The position adjusting mechanism for adjusting the exposure position in the ξ and ξ ′ directions constitutes a main and sub scanning direction orthogonal direction exposure position adjusting unit which is a first and second direction orthogonal direction exposure position adjusting unit of the present invention. .

The light emitting element supporting member 4d and the exposure apparatus support member 52a, between the side wall 52a _2, 53a ₂ of one of the 53a, a preset thickness of the rear spacer 52e ', 53e' in a predetermined number (the illustrated example 1 sheet). Then, the light emitting element support member 4d is screwed to the exposure apparatus support members 52a and 53a by the side screws 52e ₁ ′ and 53e ₁ ′, so that θ of each lens array 4a ₁ , 4a ₂ , 4a ₃ with respect to the photoreceptor 2 Adjust the position in the θ ′ direction.
Therefore, in the second embodiment, the exposure position adjustment in the θ and θ ′ directions similar to the first embodiment and the exposure position adjustment in the ξ and ξ ′ directions at the center position in the width direction of the exposure apparatus 4 were performed.

  Similarly to the first embodiment, in this second embodiment, an adjustment amount lower limit value, an adjustment amount upper limit value, a pattern that is a combination of different initial positions, and an exposure adjustment position when the focus matching range is maximum are set. ing. They are shown in Tables 6 to 8, respectively.

  As shown in Table 6, the adjustment amount lower limit value in the ξ direction of the first position adjustment mechanism 52c is set to −dξ, and the adjustment amount lower limit value in the θ direction of the first position adjustment mechanism 52c is set to −dθ. The Further, the adjustment amount upper limit value in the ξ direction of the first position adjustment mechanism 52c is set to + dξ, and the adjustment amount upper limit value in the θ direction of the first position adjustment mechanism 52c is set to + dθ. On the other hand, the adjustment amount lower limit value in the ξ ′ direction of the second position adjustment mechanism 53c is set to −dξ ′, and the adjustment amount lower limit value in the θ ′ direction of the second position adjustment mechanism 53c is set to −dθ ′. . Further, the adjustment amount upper limit value in the ξ ′ direction of the second position adjustment mechanism 53c is set to + dξ ′, and the adjustment amount upper limit value in the θ ′ direction of the second position adjustment mechanism 53c is set to + dθ ′.

As shown in Table 7, the exposure position adjustment pattern in the exposure position adjustment image initially printed in order to adjust the center of the exposure position of the light-emitting element 4b _2, 4 a pattern G in this example, H, I, J is set Is done. These patterns G, H, I, and J are different combinations of the initial positions in the ξ, θ, ξ ′, and θ ′ directions.

  First, the pattern G will be described. As shown in Table 7, the initial positions of the first position adjustment mechanism 52c in the ξ and θ directions are set to positions of −dξ and + dθ, respectively. On the other hand, the initial positions in the ξ ′ and θ ′ directions of the second position adjusting mechanism 53c are set to the positions of + dξ ′ and −dθ ′, respectively.

Next, the pattern H will be described. As shown in Table 7, the initial positions of the first position adjustment mechanism 52c in the ξ and θ directions are set to the positions of −dξ and −dθ, respectively. On the other hand, the initial positions of the second position adjusting mechanism 53c in the ξ ′ and θ ′ directions are + dξ ′ and + d, respectively.
It is set at the position θ ′.

  Next, the pattern I will be described. As shown in Table 7, the initial positions of the first position adjustment mechanism 52c in the ξ and θ directions are set to the positions of + dξ and + dθ, respectively. On the other hand, the initial positions of the second position adjusting mechanism 53c in the ξ ′ and θ ′ directions are set to the positions of −dξ ′ and −dθ ′, respectively.

  Next, the pattern J will be described. As shown in Table 7, the initial positions of the first position adjustment mechanism 52c in the ξ and θ directions are set to the positions of + dξ and −dθ, respectively. On the other hand, the initial positions of the second position adjusting mechanism 53c in the ξ ′ and θ ′ directions are set to the positions of −dξ ′ and + dθ ′, respectively.

Next, the exposure adjustment position when the focus matching range in the pattern G is the maximum will be described. As shown in Table 8, the exposure adjustment position in the ξ direction of the first position adjustment mechanism 52c is −dξ + (dξ + dξ ′) × LC / LL. The exposure adjustment position in the θ direction is + dθ− (dθ + dθ ′) × LC / LL. On the other hand, the exposure adjustment position in the ξ ′ direction of the second position adjustment mechanism 53c is + dξ ′ − (dξ + dξ ′) × (LL−LC) / LL. The exposure adjustment position in the θ ′ direction is −dθ ′ + (dθ + dθ ′) × (LL−LC) / LL.

  Next, the exposure adjustment position when the focus matching range in the pattern H is the maximum will be described. As shown in Table 3, the exposure adjustment position in the ξ direction of the first position adjustment mechanism 52c is −dξ + (dξ + dξ ′) × LC / LL. The exposure adjustment position in the θ direction is −dθ + (dθ + dθ ′) × LC / LL. On the other hand, the exposure adjustment position in the ξ ′ direction of the second position adjustment mechanism 53c is + dξ ′ − (dξ + dξ ′) × (LL−LC) / LL. The exposure adjustment position in the θ ′ direction is + dθ ′ − (dθ + dθ ′) × (LL−LC) / LL.

  Further, the exposure adjustment position when the focus matching range in the pattern I is the maximum will be described. As shown in Table 3, the exposure adjustment position in the ξ direction of the first position adjustment mechanism 52c is + dξ− (dξ + dξ ′) × LC / LL. The exposure adjustment position in the θ direction is + dθ− (dθ + dθ ′) × LC / LL. On the other hand, the exposure adjustment position in the ξ ′ direction of the second position adjustment mechanism 53c is −dξ ′ + (dξ + dξ ′) × (LL−LC) / LL. The exposure adjustment position in the θ ′ direction is −dθ ′ + (dθ + dθ ′) × (LL−LC) / LL.

  Further, the exposure adjustment position when the focus matching range in the pattern J is the maximum will be described. As shown in Table 3, the exposure adjustment position in the ξ direction of the first position adjustment mechanism 52c is + dξ− (dξ + dξ ′) × LC / LL. The exposure adjustment position in the θ direction is −dθ + (dθ + dθ ′) × LC / LL. On the other hand, the exposure adjustment position in the ξ ′ direction of the second position adjustment mechanism 53c is −dξ ′ + (dξ + dξ ′) × (LL−LC) / LL. The exposure adjustment position in the θ ′ direction is + dθ ′ − (dθ + dθ ′) × (LL−LC) / LL.

Next, the procedure for adjusting the exposure position in the second embodiment will be described. FIG. 10 is a diagram showing a flow of a procedure for performing exposure adjustment positions by the first and second position adjustment mechanisms 52c and 53C shown in FIGS.
As shown in FIG. 10, first, exposure position adjustment is started in step S21. Next, in step S22, the exposure apparatus 4 is set to the initial position of each pattern G, H, I, J. Thereafter, the pattern G, H, I, to print the central one-dot width vertical line image due to only the light-emitting element 4b ₂ of each J. Next, in step S23, a pattern in which the in-focus range 55a has the maximum width is selected.

Next, in step S24, the exposure position is adjusted according to the exposure adjustment position of the selected pattern among the patterns described in Table 8. Next, in step S25, once again, to print one dot width vertical line image due to only the center of the light emitting element 4b _2. Next, in step S26, the exposure position is adjusted again by applying Table 8 as the new positions in the ξ, θ, ξ ′, and θ ′ directions. In step S27, further again, to print one dot width vertical line image due to only the center of the light emitting element 4b _2.

Next, in step S28, it is determined whether or not the width of the in-focus range 55a is substantially the maximum exposed portion width LL. If it is determined that this width is substantially the maximum exposed portion width LL, in step S29, a one-dot width vertical line image is printed by only the light emitting elements 4b ₁ and 4b ₃ at both ends at the adjustment position again in step S26. . Next, in step S30, Table 8 is applied with each adjustment position as a new position in the ξ, θ, ξ ′, θ ′ direction, and the exposure position is adjusted again. Next, in step S31, a one-dot width vertical line image is printed again only by the light emitting elements 4b ₁ and 4b _{3 at} both ends.

  Next, in step S32, it is determined whether or not the width of the in-focus range 55a is substantially the maximum exposed portion width LL. If it is determined that this width is substantially the maximum exposure portion width LL, the adjustment of the exposure position is terminated assuming that all the focus of the three rows of light emitting elements 4b of the exposure apparatus 4 is more optimal in step S33.

  If it is determined in step S28 or S32 that the in-focus range 55a is not approximately the maximum exposure portion width LL, the exposure device 4 is discarded and replaced with another exposure device 4 in step S34. . Thereafter, the process proceeds to step S21, and exposure position adjustment is started. Thereafter, the processes in steps S21 to S34 are executed again as described above.

(Comparative Example 1)
In Comparative Example 1, a 1-dot width horizontal line (main scanning direction) image was used as the exposure position adjustment image. When printing a horizontal line image, the lighting timing of the light emitting element 4b _{2 at the} center and the light emitting elements 4b ₁ and 4b ₃ at both ends is controlled in accordance with the moving speed of the photoconductor 2 so that a continuous image can be drawn. In Comparative Example 1, the adjustment at the initial position of the exposure apparatus is performed in the same manner as in Example 1, but the adjustment of the exposure position in the present invention is not performed. In this comparative example 1, as shown in FIG. 11, when the focus is not in focus, the 1-dot width horizontal line latent image becomes shallow and is shaken by the ribs described above, and the horizontal line image 56 has a portion 56 a where the horizontal line is interrupted. A portion 56b in which the horizontal line is disturbed and a portion 56c in which the horizontal line is blurred are generated. Thus, it is difficult to obtain a normal image unless the light emitting element 4b is in focus. For convenience of explanation, FIG. 11 also shows several cases where it is determined that the focus is not correct, such as a portion 56a where the horizontal line is interrupted and a portion 56b where the width of the horizontal line is disturbed. Further, when the exposure position adjustment image is a horizontal line image, not only the horizontal line width disturbance is small, but also the horizontal line width fluctuation occurs due to uneven rotation speed of the photosensitive member 2, so that the one-dot width horizontal line is in focus. It is difficult to accurately determine the range.

(Comparative Example 2)
In Comparative Example 2, a one-dot image and a one-dot width vertical line image were used as the exposure position adjustment image. Even in Comparative Example 2, the adjustment at the initial position of the exposure apparatus is performed in the same manner as in Example 1, but the adjustment of the exposure position in the present invention is not performed. As shown in FIG. 12A, in the one-dot image 57, since the dot images 57 are relatively aligned in the region 57a of the one-dot image 57, it may be determined that the image is in focus. However, as shown in FIG. 12B, when a one-dot width vertical line image 58 is drawn as an exposure position adjustment image with the same exposure apparatus 4, a continuous one-dot width in the region 58a (corresponding to the region 57a described above). A line image is not drawn and it is detected that the subject is not in focus. Therefore, it is difficult to accurately determine the in-focus range even in a one-dot image, as in the case of the one-dot width horizontal line described above. Therefore, it is preferable to use the 1-dot width vertical line image 58 as the exposure position adjustment image because the focused range can be accurately determined.

  Table 9 shows the pass rates of the exposure apparatus 4 in Examples 1 and 2 and Comparative Examples 1 and 2. In this case, if the width in focus at the exposure position adjustment at the initial position is approximately the maximum exposed portion width LL, it is accepted, and if this width is less than the maximum exposed portion maximum width LL, it is not acceptable. Passed. In Table 9, the pass rate of the exposure apparatus 4 is expressed as a percentage of the number of exposure apparatuses that have passed per 10,000 per month. And the pass rate of the exposure apparatus 4 determined 80% or more as good, and determined less than 80% as bad.

  As shown in Table 9, in Example 1, the pass rate of the exposure apparatus 4 was 99.99%, and in Example 2, the pass rate of the exposure apparatus 4 was 81.35%. In Comparative Example 1, the pass rate of the exposure apparatus 4 was 78.82%, and in Comparative Example 2, the pass rate of the exposure apparatus 4 was 66.47%. Thus, it was confirmed that an exposure apparatus using the lens array and the light emitting element group can draw a good latent image in focus on the photoreceptor 2 by performing the exposure position adjustment of the present invention. It was also confirmed that in the same exposure apparatus, a good latent image in focus could not be drawn on the photosensitive member 2 unless the exposure position adjustment of the present invention was performed.

FIG. 17 is a view similar to FIG. 5 schematically and partially showing another example of the embodiment of the image forming apparatus according to the present invention.
As shown in FIG. 17, in the exposure apparatus 4 of this example, the second exposure position adjusting device 53 is replaced with the two first and second position adjusting mechanisms 53c and 53d of the exposure apparatus 4 of the example shown in FIG. One fourth position adjustment mechanism 53f is provided. The fourth position adjusting mechanism 53f is provided with a fourth position adjusting screw 53f ₁ provided on the light emitting element supporting member 4d at the center in the longitudinal direction or substantially at the center. In that case, the fourth position adjusting screw 53f ₁ is threaded through the light emitting element support member 4d in the vertical direction in FIG. A hemispherical lubricating member 53f ₂ made of, for example, a resin having lubricity is also fixed to the lower end of the fourth position adjusting screw 53f ₁ . The spherical surface portion of the lubricating member 53f ₂ is in contact with the outer peripheral surface of the non-image portion of the photoreceptor 2.

The first exposure position adjusting device 52 is the same as the first exposure position adjusting device 52 of the first embodiment shown in FIGS. Therefore, in the exposure apparatus 4 of this example, the first exposure position adjusting device 52 side is supported by two points, and the second exposure position adjusting device 52 side is supported by three points. Other configurations of the image forming apparatus 1 and the exposure apparatus 4 in this example are the same as those in the first embodiment.
In the exposure apparatus 4 of this example, the exposure position is adjusted according to the same procedure as in the first embodiment. Even in the exposure apparatus 4 of this example, it is possible to obtain the same effects as those of the first embodiment.

FIG. 18 is a view similar to FIG. 5 schematically and partially showing still another example of the embodiment of the image forming apparatus according to the present invention.
As shown in FIG. 18, in the exposure apparatus 4 of this example, the first and second exposure position adjusting devices 52 and 53 are each provided with two first and second position adjusting mechanisms 53c as in the first embodiment shown in FIG. , 53d. In this case, as in the first embodiment, these first and second position adjusting mechanisms 53c and 53d also have first and second position adjusting screws 52c ₁ and 53c ₁ ; 52d ₁ and 53d ₁ , respectively. is doing. Hemispherical lubricating members 52c ₂ , 53c ₂ ; 52d ₂ , 53d ₂ similar to those of the first embodiment are fixed to the lower ends of the first and second position adjusting screws 52c ₁ , 53c ₁ ; 52d ₁ , 53d _1. ing. 18 shows a main body 1a of the lubricating members 52c ₂ , 53c ₂ ; 52d ₂ , 53d ₂ in the vicinity of the photosensitive member 2 (corresponding to a flange supporting the photosensitive member 2 of the present invention). And is supported by the upper surface 1a ₁ . Other configurations of the image forming apparatus 1 and the exposure apparatus 4 in this example are the same as those in the first embodiment. In the exposure apparatus 4 of this example, the exposure position is adjusted according to the same procedure as in the first embodiment.

According to the exposure apparatus 4 of this example, the lens arrays 4a ₁ , 4a ₂ , 4a ₃ and the light emitting elements 4b ₁ , 4b ₂ , 4b ₃ are supported by the apparatus main body 12a located in the vicinity of the photoconductor 2 to thereby perform photosensitivity. The influence of vibration generated from the body 2 can be suppressed, and stable writing of an image becomes possible. Other functions and effects of the exposure apparatus 4 of this example are the same as those of the first embodiment.

FIG. 19 is a view similar to FIG. 5 schematically and partially showing still another example of the embodiment of the image forming apparatus according to the present invention.
As shown in FIG. 19, in the exposure apparatus 4 of this example, the first and second exposure position adjusting devices 52 and 53 are each provided with two first and second position adjusting mechanisms 53c as in the first embodiment shown in FIG. , 53d. In this case, as in the first embodiment, these first and second position adjusting mechanisms 53c and 53d also have first and second position adjusting screws 52c ₁ and 53c ₁ ; 52d ₁ and 53d ₁ , respectively. is doing. Hemispherical lubricating members 52c ₂ , 53c ₂ ; 52d ₂ , 53d ₂ similar to those of the first embodiment are fixed to the lower ends of the first and second position adjusting screws 52c ₁ , 53c ₁ ; 52d ₁ , 53d _1. ing. The spherical surface portions of the lubricating members 52c ₂ , 53c ₂ ; 52d ₂ , 53d ₂ are in contact with the outer peripheral surfaces of the non-image portions of the photosensitive member 2, respectively.

Further, the irradiation positions 4e ₁ , 4e ₂ , 4e ₃ of the three rows of lens arrays 4a ₁ , 4a ₂ , 4a ₃ and the light emitting elements 4b ₁ , 4b ₂ , 4b _{3 on} the surface of the photosensitive member 2 are all sub-scanned. Contact positions (supports) of the spherical portions of the lubricating members 52c ₂ , 53c ₂ ; 52d ₂ , 53d ₂ of the first and second position adjusting screws 52c ₁ , 53c ₁ ; 52d ₁ , 53d _{1 in} the direction (support) Point). Therefore, the first and second position adjusting screws 52c ₁ , 53c ₁ ; 52d ₁ , 53d ₁ are lubricated members 52c ₂ , 53c ₂ ; 52d ₂ , 53d ₂ of the support points on the photosensitive member 2 in the sub-scanning direction. Substantially W ₁ is the sub-scanning direction of the irradiation positions 4e ₁ , 4e ₂ , 4e _{3 on} the surface of the photoreceptor 2 of the three rows of lens arrays 4a ₁ , 4a ₂ , 4a ₃ and the light emitting elements 4b ₁ , 4b ₂ , 4b ₃ Is set larger than the maximum width W ₂ (that is, the maximum width in the sub-scanning direction of the irradiation region of the light emitting elements 4b ₁ , 4b ₂ , 4b ₃ ) (W ₁ > W ₂ ). Other configurations of the image forming apparatus 1 and the exposure apparatus 4 in this example are the same as those in the first embodiment. In the exposure apparatus 4 of this example, the exposure position is adjusted according to the same procedure as in the first embodiment.

According to the exposure apparatus 4 of this example, the maximum width W ₁ in the sub-scanning direction of the support point of the first and second position adjusting screws 52c ₁ , 53c ₁ ; 52d ₁ , 53d _{1 on} the photosensitive member 2 is set to each lens. The array 4a ₁ , 4a ₂ , 4a ₃ and the light emitting elements 4b ₁ , 4b ₂ , 4b ₃ are set to be larger than the maximum width W _{2 in} the sub-scanning direction of the irradiation positions 4e ₁ , 4e ₂ , 4e _{3 on} the surface of the photoreceptor 2. is doing. Therefore, the exposure apparatus 4 can be positioned stably. Further, each of the first and second position adjusting screws 52c _1, 53c _1; 52 d _1, the lens array 4a ₁ against adjusting operation amount of 53d _1, 4a _2, 4a ₃ and the light-emitting elements 4b _1, 4b _2, The adjustment amount of the irradiation positions 4e ₁ , 4e ₂ , 4e ₃ of 4b ₃ becomes small. As a result, the adjustment of the irradiation positions 4e ₁ , 4e ₂ , 4e ₃ of the lens arrays 4a ₁ , 4a ₂ , 4a ₃ and the light emitting elements 4b ₁ , 4b ₂ , 4b ₃ is made finer, more accurate and easier. Can be done. Other functions and effects of the image forming apparatus 1 and the exposure apparatus 4 in this example are the same as those of the first embodiment.

FIG. 20 is a diagram schematically and partially showing another example of the embodiment of the image forming apparatus of the present invention.
In each example of the above-described embodiment, the exposure apparatus 1 is supported by the first and second exposure position adjusting apparatuses 52 and 53 supported by the apparatus main body 1a of the image forming apparatus 1. In each of the above-described embodiments, the exposure apparatus 1 does not include the first and second exposure position adjustment apparatuses 52 and 53. On the other hand, as shown in FIG. 20, in the image forming apparatus 1 of this example, the first and second exposure position adjusting devices 52 and 53 are incorporated in the exposure device 4. That is, the exposure apparatus 4 of this example includes first and second exposure position adjusting apparatuses 52 and 53. The exposure apparatus 4 itself is supported by the apparatus main body 1a. In that case, the first and second exposure position adjusting devices 52 and 53 of the exposure apparatus 4 are supported by the apparatus main body 1a. According to the exposure apparatus 4 of this example, since the first and second exposure position adjusting apparatuses 52 and 53 are provided, the exposure apparatus 4 can be easily assembled to the apparatus main body.
Other configurations and other functions and effects of the image forming apparatus 1 of this example are the same as those of the above-described examples.

  The present invention is not limited to each example of the above-described embodiment, and the light emitting elements are two-dimensionally arranged in the main scanning direction which is the first direction and the sub scanning direction which is the first direction. As long as the exposure apparatus includes an array and a lens array and the image forming apparatus including the exposure apparatus, the present invention can be applied to any exposure apparatus and the image forming apparatus including the exposure apparatus. The exposure position adjustment mechanism of the present invention can use other exposure position adjustment mechanisms in addition to the exposure position adjustment mechanism using the screw in the above-described example. In short, the present invention can be modified in various ways within the scope of the matters described in the claims.

1 is a diagram schematically and partially showing an example of an embodiment of an image forming apparatus according to the present invention. It is a perspective view of the exposure apparatus used for the image forming apparatus shown in FIG. It is a figure which shows typically the cross section which follows the III-III line in FIG. It is a figure explaining the beam spot and imaging by the exposure apparatus shown in FIG. It is sectional drawing which shows typically the exposure position adjustment apparatus of this example, and follows the VV line in FIG. It is a figure which shows typically the exposure position adjustment image initially printed. It is a figure which shows the flow of the procedure which performs the exposure adjustment position by the exposure position adjustment apparatus of the example shown in FIG. It is sectional drawing similar to FIG. 5, which shows typically the exposure position adjustment apparatus of another example. FIG. 9 is a perspective view schematically showing the exposure position adjusting apparatus of the example shown in FIG. 8, similar to FIG. 2. It is a figure which shows the flow of the procedure which performs the exposure adjustment position by the exposure position adjustment apparatus of the example shown in FIG. It is a figure which shows the horizontal line image in the comparative example 1. The horizontal line image in the comparative example 2 is shown, (a) is a figure which shows a 1 dot image, (b) is a figure which shows a 1 to 3 dot width vertical line image. It is a figure explaining the behavior of the liquid developer which transfers from a developing roller to a photoreceptor. It is a figure explaining the rib in a liquid developer. It is a figure which shows the relationship between the magnitude | size of exposure, and a latent image electric potential. It is a figure explaining disorder of a 1 dot width vertical line image. FIG. 6 is a view similar to FIG. 5 schematically and partially showing another example of the embodiment of the image forming apparatus according to the present invention. FIG. 6 is a view similar to FIG. 5 schematically and partially showing still another example of the embodiment of the image forming apparatus according to the present invention. FIG. 6 is a view similar to FIG. 5 schematically and partially showing still another example of the embodiment of the image forming apparatus according to the present invention. FIG. 6 is a view similar to FIG. 5 schematically and partially showing still another example of the embodiment of the image forming apparatus according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 1a ... Apparatus main body, 2Y, 2M, 2C, 2K ... Photosensitive body of each color, 3Y, 3M, 3C, 3K ... Charging device, 4, 4Y, 4M, 4C, 4K ... Exposure device, 4a ... Lens array, 4a ₁ , ₃ ... Lens array at both ends, 4a ₂ ... Center lens array, 4b ... Light emitting element, 4b ₁ , ₃ ... Light emitting element at both ends, 4b ₂ ... Light emitting element at the center, 4d ... Light emitting element Support member, 5Y, 5M, 5C, 5K ... developing devices for each color, 19, 19Y, 19M, 19C, 19K ... developing roller, 52 ... first exposure position adjusting device, 53 ... second exposure position adjusting device, 52a, 53a ... exposure device support member, 52 b, 53b ... resilient back plate, 52c, 53c ... first position adjusting mechanism, 52c _1, 53c ₁ ... first position adjustment screw, 52 d, 53d second position adjusting mechanism, 52 d _1, 53d ₁ ... Second position adjusting screw, 52e, 53e third position adjusting mechanism, 2e _1, 53e ₁ ... third position adjusting screw, 53f ₁ ... fourth position adjusting screw

Claims (10)

A light emitting element array having a plurality of light emitting elements disposed in a first direction and a second direction orthogonal or substantially orthogonal to the first direction, and a plurality of lenses for imaging light from the light emitting elements. An exposure position adjustment mechanism having a lens array, a support member that supports the light emitting element array and the lens array, and a rotation adjustment unit that rotates the support member about or substantially around the axis in the first direction; ,
An exposure apparatus comprising:   The exposure apparatus according to claim 1, wherein the exposure position adjustment mechanism includes a second direction exposure position adjustment unit that moves the support member in the second direction.   The exposure position adjustment mechanism includes first and second direction orthogonal direction exposure position adjustment units that move the support member in a direction orthogonal to both the first direction and the second direction. The exposure apparatus according to claim 2, characterized in that: A latent image carrier on which an electrostatic latent image is formed;
The exposure apparatus according to any one of claims 1 to 3, wherein the electrostatic latent image is written on the latent image carrier.
A developing device for developing the electrostatic latent image with a developer;
An image forming apparatus comprising: A latent image carrier on which an electrostatic latent image is formed;
A light-emitting element array having a plurality of light-emitting elements disposed in a first direction and a second direction orthogonal or substantially orthogonal to the first direction, and a lens having a plurality of lenses that image light from the light-emitting elements An exposure apparatus having an array, and a support member that supports the light emitting element array and the lens array;
An exposure position adjustment mechanism having a rotation adjustment unit that rotates the support member about the axis in the first direction as a center or a substantially center;
A developing device for developing the electrostatic latent image with a developer;
An image forming apparatus comprising:   The image forming apparatus according to claim 4, wherein the developing device is a developing device that develops the electrostatic latent image with a liquid developer that shakes toner and a liquid carrier.   The image forming apparatus according to claim 4, wherein one end of the supporting member is supported at two points by a photosensitive member or a flange that supports the photosensitive member.   The support member is supported at one or more points on one side end of the photosensitive member or the flange supporting the photosensitive member, and is supported at one point or more on the flange supporting the photosensitive member or the photosensitive member. The image forming apparatus according to claim 4, wherein the image forming apparatus is an image forming apparatus.   The maximum width in the second direction of the support point at the one side end of the support member is larger than the maximum width in the second direction of the irradiation region in the photosensitive member irradiated with light from the light emitting element. The image forming apparatus according to claim 7, wherein the image forming apparatus is an image forming apparatus.   10. The rotation adjusting unit rotates the support member around an axis in the first direction at a center position in the second direction at the exposure position as a center or substantially a center. The image forming apparatus according to any one of the above.

Images