JP7139831B2 - image forming device - Google Patents

Description

The present invention relates to an image forming apparatus.

Conventionally, an exposure means for forming a latent image is provided movably between an exposure position such as a latent image forming position and a non-exposure position such as a retracted position, and the exposure means is appropriately fixed at the exposure position. As the configured image forming apparatus, for example, those described in Patent Documents 1 and 2 shown below are known.

In Japanese Patent Laid-Open No. 2002-100000, a write head in an exposure unit is held by a holder while being urged toward a photoreceptor by a spring member, and a support projection and a guide projection provided on the holder are retracted by a retraction mechanism. is movably provided so as to be guided along the trajectory of the exposure guide hole in the second link of the process cartridge. An image forming device positioned with a

Japanese Unexamined Patent Application Publication No. 2002-200002 discloses a means for pressing an exposure member toward a photoreceptor, a gap holding member for holding a gap from the photoreceptor, and a photoreceptor by regulating the movement of the exposure member in the rotation direction of the photoreceptor. An image forming apparatus is disclosed that includes a positioning member that determines the position of the exposure member in the rotation direction of the body, and a swing restricting member that restricts swinging of the exposure member about the positioning member. Further, Japanese Patent Application Laid-Open No. 2002-200000 describes further providing a first pressing member that presses the exposure member toward the positioning member and a second pressing member that presses the exposure member toward the swing restricting member.

Japanese Patent No. 6112410 (paragraphs 0030-0033, FIGS. 3-7, etc.) Japanese Patent No. 4645691 (claims 1-3, FIG. 4, etc.)

In this invention, an exposing means held by a holding means provided with a plurality of projections guided by a guide groove for guiding movement between an exposure position and a non-exposure position is pressed when the exposing means is moved to the exposure position. In the state of being pressed by the means, contacting the positioning part and being positioned, it becomes unstable due to rattling. To provide an image forming apparatus which can be suppressed compared to the case where it is not arranged in a positional relationship to be in a state.

The image forming apparatus of this invention (A1) is
holding means for holding exposure means for forming a latent image and having a plurality of projections at both ends in the longitudinal direction;
a pair of support means each provided with a guide groove for guiding the plurality of protrusions so as to move the exposure means to an exposure position and a non-exposure position;
a positioning unit that contacts and positions the exposure unit when the exposure unit is moved to the exposure position;
pressing means for pressing the exposure means or the holding means so as to press the exposure means against the positioning portion;
power means for generating and transmitting power for moving the exposure means to one of the plurality of projections;
with
The plurality of projections on both ends of the holding means and the pressing means are, when the exposure means is positioned by coming into contact with the positioning part, the projections other than the projections receiving the power for the movement among the plurality of projections. One of them is arranged in a positional relationship such that it receives a force to be pressed against the guide groove due to the pressing force of the pressing means.

The image forming apparatus according to the present invention (A2) is the image forming apparatus according to the invention A1, wherein, of the plurality of projections, the projection that receives the power when moving is positioned by the exposure means contacting the positioning portion. When pressed, it is guided by the guide groove and stopped at a position deviated in a direction intersecting the straight line along the direction in which the pressing force of the pressing means acts.
The image forming apparatus according to the present invention (A3) is the image forming apparatus according to the invention A2, wherein one of the plurality of protrusions other than the protrusion receiving power when moving is brought into contact with the positioning portion by the exposure means. When it is positioned as above, it is guided by the guide groove and stopped at a position on the opposite side of the pressing means from the protrusion that receives power when moving.

The image forming apparatus of this invention (A4) is the image forming apparatus of any one of the above inventions A1 to A3, wherein the pressing force of the pressing means has a force component in a direction overlapping the optical axis of the exposure of the exposure means. It is arranged to act as
The image forming apparatus according to this invention (A5) is the image forming apparatus according to any one of the above inventions A1 to A4, wherein the holding means is provided with two projections at both ends thereof, and the pair of supporting means comprises: , two or more guide grooves for individually guiding the two projections are provided.
The image forming apparatus of this invention (A6) is the image forming apparatus according to any one of the above inventions A1 to A5, wherein the exposure means is held by the holding means in a displaceable state toward the positioning section, The pressing means is arranged between the holding means and the exposing means.
The image forming apparatus according to this invention (A7) is the image forming apparatus according to any one of the inventions A1 to A6, wherein, among the plurality of projections, the projections pressed against the guide grooves, the holding means, and the pair of supporting means are: It is made of a conductive material.

According to the image forming apparatus of invention A1, the exposure means held by the holding means provided with a plurality of projections guided by the guide grooves for guiding the movement between the exposure position and the non-exposure position moves to the exposure position. When it is moved, it contacts the positioning portion in a state of being pressed by the pressing means, and becomes unstable due to rattling at the stage of being positioned. It can be suppressed compared to the case where it is not arranged in a positional relationship in which it receives a force pressed against.

According to the image forming apparatus of the invention A2, the exposure means contacts the exposure position positioning portion more than the case where the protrusion that receives the power when moving is not arranged in the positional relationship described above with respect to the pressing means. It is possible to more accurately suppress the rattling and instability at the stage of being positioned by hand.
According to the image forming apparatus of invention A3, compared to the case where one of the plurality of protrusions other than the protrusion that receives power when moving is not arranged in the positional relationship described above with respect to the pressing means, the first It becomes easy to stably keep the state in which the two projections receive the force pressed against the guide groove.

According to the image forming apparatus of the invention A4, the pressing means is arranged so that the pressing force having a component in the direction overlapping with the optical axis line in the exposure of the exposing means is not applied. It is effectively positioned by coming into contact with the positioning portion of the position, and it is suppressed that it becomes unstable due to rattling at the positioned stage.
According to the image forming apparatus of the invention A5, compared to the case where the two projections on both ends of the holding means are guided by one guide groove in the pair of supporting means, the exposure means is positioned at the exposure position positioning portion. It is possible to more reliably suppress rattling and instability at the stage of contact and positioning.
According to the image forming apparatus of the invention A6, the exposure means is positioned at the exposure position positioning portion compared to the case where the pressing means is not arranged between the holding means and the exposure means displaceably held by the holding means. With a simpler configuration, it is possible to suppress instability due to rattling at the stage of being positioned in contact with the .
According to the image forming apparatus of the invention A7, compared to the case where the protrusions pressed against the guide grooves, the holding means, and the pair of supporting means are not made of a material having conductivity, the exposure means moves to the exposure position. stable grounding can be realized without adding parts.

1 is a schematic diagram showing the main configuration of an image forming apparatus according to Embodiment 1; FIG. 1 is a schematic diagram showing an image forming device and the like in an image forming apparatus; FIG. 1 is a schematic diagram showing a detachable structure portion of an image forming apparatus; FIG. 2 is a schematic perspective view showing a state in which an opening/closing cover of a housing of the image forming apparatus is opened; FIG. FIG. 2 is a schematic diagram showing a movement mechanism of an exposure apparatus and a state when it is moved to each position; It is a schematic perspective view which shows the moving apparatus which integrated the moving mechanism and the link mechanism. It is a schematic perspective view showing a state where some parts of the moving device are omitted and a moving device portion. It is a schematic perspective view which shows the attachment state to the housing|casing of a moving apparatus. (a) is a schematic diagram showing the state when the exposure device is moved to the exposure position by the moving mechanism of the left moving device, and (b) is the state when the exposure device is moved to the retracted position by the moving mechanism. It is a schematic diagram showing (a) is a schematic diagram showing the state when the exposure device is moved to the exposure position by the movement mechanism of the right moving device, and (b) is the state when the exposure device is moved to the retracted position by the movement mechanism. It is a schematic diagram showing FIG. 4 is a schematic diagram showing the state of the moving device when the exposure device is moved to the exposure position; 1 is a schematic perspective view showing the appearance of an exposure device; FIG. (a) is a schematic perspective view showing one end portion of an exposure device, and (b) is a schematic perspective view showing a state in which a holding member is removed from the exposure device of (a). 4 is a schematic diagram showing the relationship between the positioning section and the exposure device in the detachable unit; FIG. 4 is a schematic diagram showing the positional relationship between projections and pressing means in an exposure device; FIG. 4 is a schematic diagram showing a state in which the exposure device is moved to the exposure position by the moving device and is positioned by contacting the positioning portion; FIG. FIG. 2 is a schematic diagram showing a state and the like when positioned at an exposure position of an exposure device; 2 is a schematic diagram showing part of an image forming apparatus according to Embodiment 2; FIG. 19 is a schematic diagram showing a state of part of the image forming apparatus of FIG. 18; FIG. FIG. 11 is a schematic diagram showing part of an image forming apparatus according to Embodiment 3; 21 is a schematic diagram showing a state of part of the image forming apparatus of FIG. 20; FIG. FIG. 10 is a schematic diagram showing a part of an image forming apparatus as a modified example and its state;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[Embodiment 1]
1 to 5 show Embodiment 1 of the present invention. FIG. 1 shows the main configuration of an image forming apparatus according to Embodiment 1, FIG. 2 shows an image forming device and the like in the image forming apparatus 1, FIG. 4 shows the structure of the housing of the image forming apparatus 1, and FIG.
Arrows indicated by symbols X, Y, and Z in each drawing indicate directions of width, height, and depth assumed in each drawing. In addition, in the arrow where only the arrows of X and Y intersect, the direction of Z is the direction directed vertically downward in the drawing from the intersecting portion.

<Overall Configuration of Image Forming Apparatus>
The image forming apparatus 1 is configured as a printer, which is an example of an image forming apparatus, and is composed of a developer (toner) based on image information such as characters, photographs, graphics, etc. input from the outside. An image is formed on recording paper 9, which is an example of a recording material.
Further, as shown in FIG. 1 and the like, the image forming apparatus 1 forms a toner image made of toner as a developer inside a housing 10 which is the main body of the apparatus by an image forming method such as an electrophotographic method. An image forming device 2 for transferring onto recording paper 9, a paper feeding device 3 for accommodating required recording paper 9 and supplying it to the transfer position of the image forming device 2, and a fixing device 4 for fixing the toner image transferred onto the recording paper 9. etc.

The housing 10 is composed of various members such as structural members and exterior materials. Further, the housing 10 is provided at its upper portion with a discharge/accommodation section 13 for containing the recording paper 9 on which an image is formed and discharged. The discharge/receiving portion 13 is configured as a receiving surface including a slope portion 13a provided below the discharge port 14 provided in the housing 10 and a horizontal surface portion 13b continuing from the upper end of the slope portion 13a. The recording paper 9 ejected from 14 is accommodated in a stacked state.

As shown in FIGS. 1 and 2, the imaging device 2 includes a charging device 22, an exposure device 23, a developing device 24, a transfer device 25, a cleaning device, and a photosensitive drum 21, which rotates in the direction indicated by an arrow A. The device 26 and the like are arranged in this order.

Among these, the charging device 22 is a contact charging type device or the like that charges the peripheral surface of the photosensitive drum 21 (the peripheral surface portion serving as the image forming area) to a required polarity and potential.
The exposure device 23 is an example of exposure means, and irradiates the charged peripheral surface of the photosensitive drum 21 with light corresponding to image information (signals) input to the image forming apparatus 1 in various ways. A device that forms an electrostatic latent image. As the exposure device 23, for example, an LED array type exposure device is applied.
The developing device 24 is a device that develops the electrostatic latent image on the photosensitive drum 21 into a toner image by supplying toner as developer from the developing roll 241 . The developing device 24 is replenished with developer through a replenishment portion 244 from a developer storage container 28 that stores replenishment developer (mainly toner).
The transfer device 25 is, for example, a contact transfer type device that electrostatically transfers the toner image on the photosensitive drum 21 to the recording paper 9 . The cleaning device 26 is a device that cleans the peripheral surface of the photosensitive drum 21 by removing unnecessary substances such as toner adhering to and remaining on the peripheral surface of the photosensitive drum 21 .

Further, as shown in FIG. 2, the image forming device 2 includes a photosensitive drum 21, a charging device 22, a developing device 24, and a cleaning device 26, which constitute a part of the image forming device 2, as an integrated structure. , and is configured as a detachable unit 20 (a portion surrounded by a two-dot chain line) detachably attached to the housing 10 . The developer storage container 28 is also configured as a detachable component detachably attached to the housing 10 (strictly speaking, the detachable unit 20) as shown in FIG.
As shown in FIG. 2, the detachable unit 20 is provided with a mounting portion 20b for mounting the developer container 28 on a part of the support frame of the unit.

The sheet feeding device 3 is arranged at a position away from the image forming device 2 on the lower side in the direction of gravity. The paper feeding device 3 includes a paper container 31 for containing a plurality of sheets of recording paper 9 of a required size, type, etc., used for forming an image, stacked on a stacking plate 31a. It is composed of a sending device 32 and the like for sending out the recording sheets 9 stored in the unit one by one.
The paper container 31 is attached to the housing 10 so that it can be pulled out, and a plurality of paper containers are provided according to the mode of use. The sheet container 31 is operated, for example, by grasping a recessed handle 316 provided on the exterior material and pulling it out. As the recording paper 9, for example, a recording medium such as plain paper, coated paper, or thick paper cut into a predetermined size is used.

The fixing device 4 is arranged at a position separated from the imaging device 2 in a substantially horizontal direction (a direction substantially parallel to the coordinate axis X). The fixing device 4 is configured by arranging a heating rotary member 41 and a pressure rotary member 42 that rotate in contact with each other inside a housing 40 provided with an inlet and an outlet.
As shown in FIG. 1, the heating rotator 41 is driven to rotate in the direction indicated by the arrow, and is heated by a heating means (not shown) to maintain the peripheral surface temperature at a required temperature. It is a fixing member for heating consisting of a form and the like. The pressurizing rotator 42 is a pressurizing fixing member in the form of a roll, a belt, or the like, which rotates so as to contact and follow the heating rotator 41 substantially along the axial direction with a required pressure. Further, the fixing device 4 passes the recording paper 9 onto which the unfixed toner image has been transferred through the portion where the heating rotator 41 and the pressurizing rotator 42 are in contact with each other to perform the required fixing process (heating, pressing, etc.). etc.).

Further, in the image forming apparatus 1, a main paper transport path for the recording paper 9 inside the housing 10 is provided, as indicated by the one-dot chain line Rt in FIG.
The main paper transport paths include a supply transport path Rt1 provided between the feeding device 32 of the paper feeding device 3 and the transfer position TP of the image forming device 2 (the position where the photosensitive drum 21 faces the transfer device 25), A relay transport path Rt2 provided between the transfer position TP of the imaging device 2 and the fixing processing section FN of the fixing device 4, and an ejection provided between the fixing processing section FN of the fixing device 4 and the ejection port 14 of the housing 10. These include a transport path Rt3, a double-sided transport path Rt4 provided between the end (branch portion) of the discharge transport path Rt3 and the middle (merge portion) of the supply transport path Rt1.

Of these, the supply transport path Rt1 is formed using a plurality of transport roll pairs 34a and 34b, a plurality of transport guide members (not shown), and the like. The transport roll pair 34b is configured as a so-called registration roll pair that feeds the recording paper 9 toward the transfer position TP of the image forming device 2 by starting rotation in accordance with the transfer timing.
The discharge transport path Rt3 is formed using a plurality of transport roll pairs 35a and 35b and a plurality of transport guide members (not shown). The conveying roll pair 35 b is configured as a discharge roll pair that feeds out the recording paper 9 after fixing to the discharge accommodating section 13 .
The double-sided transport path Rt4 switches between a transport roll pair 35b as a forward and reverse rotatable discharge roll pair, a plurality of transport roll pairs 36a, 36b, and 36c, and the destination of the recording paper 9, which forms the end of the discharge transport path Rt3. It is formed by a route switching member (not shown), a plurality of transport guide members (not shown), and the like. The transport roll pair 36a shares the drive roll with the transport roll pair 35a in the discharge transport path Rt3.

<Configuration of detachable structure>
In this image forming apparatus 1, as shown in FIG. 3, the attachment/detachment unit 20 and the developer storage container 28, which constitute a part of the image forming apparatus 2, are detachably attached to the housing 10. there is

The attachment/detachment (operation) of the attachment/detachment unit 20 and the developer storage container 28 is performed after opening the opening/closing cover 15 provided on a part of the housing 10 as shown in FIGS. done.

As shown in FIGS. 3 and 4, the opening/closing cover 15 is swung in directions indicated by arrows B1 and B2 with a fulcrum shaft 16 provided on one side surface (for example, an operation front surface) of the housing 10 as a fulcrum. It opens and closes by As shown in FIGS. 3 and 4, when the opening/closing cover 15 is opened by swinging in the direction indicated by the arrow B1, a portion of one side surface of the housing 10 and a portion of its upper surface are opened. (The portion where the horizontal surface portion 13b of the discharge storage portion 13 exists) can be exposed to the outside.

In addition, as shown in FIG. 3, the image forming apparatus 1 has a first attachment/detachment passage space inside the housing 10, which serves as a passage through which the developer storage container 28 passes when the developer storage container 28 is attached or detached. S1 and a second attachment/detachment passage space S2 serving as a passage for the attachment/detachment unit 20 to pass when the attachment/detachment unit 20 is attached/detached are provided.
The first attachment/detachment passage space S1 and the second attachment/detachment passage space S2 overlap each other with the lower part of the first attachment/detachment passage space S1 biting into a part of the second attachment/detachment passage space S2. This is because the mounting portion 20b for mounting the developer container 28 is provided in a part of the detachable unit 20 as described above.

Further, in the image forming apparatus 1, when the detachable unit 20 is attached and detached, the exposure device 23, which does not constitute the detachable unit 20, is located at a position (see FIG. 3) of the exposure device indicated by the two-dot chain line.
Therefore, in the image forming apparatus 1, when the detachable unit 20 is detached and detached, the detachable unit 20 is moved from the exposure position P1 at which the exposure device 23 performs exposure when forming an electrostatic latent image by the moving mechanism 5, which will be described later. 20 is configured to be moved to a retracted position P2, which is an example of a non-exposure position retracted so as not to hinder the movement of 20. The exposure position P1 at this time is the position of the exposure device 23 indicated by the solid line in FIG. 1 or the two-dot chain line in FIG. The retracted position P2 is the position of the exposure device 23 indicated by the solid line in FIG.

<Configuration of moving mechanism>
The moving mechanism 5 of the exposure device 23 moves the exposure device 23 between the exposure position P1 and the retraction position P2 in which the stop posture is different from the posture where the exposure device 23 is stopped at the exposure position P1, as shown in FIG. It is a mechanism that allows

As shown in FIGS. 5 to 8, 12, etc., the moving mechanism 5 is provided at both ends (specifically, mounting members 236) in the longitudinal direction of holding means (holding members 232), which will be described later and holds the exposure device 23. a first projection 51 and a second projection 52 provided at different positions, a first guide groove 53 for guiding the first projection 51 between the exposure position P1 and the retracted position P2, and the second projection 52 at the exposure position P1 and the retracted position P2.
The moving mechanism 5 in Embodiment 1 includes two left and right moving mechanisms 5A and 5B (specifically, the left moving mechanism 5A and the right moving mechanism 5A) arranged at two positions facing the longitudinal ends of the exposure device 23, respectively. It is configured as a moving mechanism 5B).

The moving mechanism 5 (5A, 5B) is configured to move the exposure device 23 between the exposure position P1 and the retracted position P2 in conjunction with the opening/closing operation of the opening/closing cover 15. FIG.
In order to realize this interlocking function, the image forming apparatus 1 includes a link mechanism 6, which will be described later, as means for converting the rocking motion of the open/close cover 15 during the opening/closing operation into power for the moving operation of the moving mechanisms 5A and 5B and transmitting the power. We are hiring.

The first guide groove 53 and the second guide groove 54 in the moving mechanisms 5A and 5B are, as shown in FIGS. 171B, respectively.
Both the first guide groove 53 and the second guide groove 54 are curved guide grooves each having a required length, but the overall shapes thereof are different from each other. Among these, the first guide groove 53 is a groove that mainly guides the exposure device 23 to move toward the exposure position P1 and the retracted position P2. The second guide groove 54 is a groove that mainly guides the exposure device 23 to adjust the stop posture at the exposure position P1 and the stop posture at the retracted position P2 while moving.
As for the retracted position P2, which is the second position, as shown in FIG. It is set at a position that is part of the space S5.

Further, the moving mechanisms 5A and 5B are interlocked with the opening/closing operation of the opening/closing cover 15 and operate as follows.
First, when opening the opening/closing cover 15, as shown in FIGS. 3, 9B, 10B, etc., the movement mechanisms 5A and 5B move the exposure device 23 to the exposure position in conjunction with the opening operation. It operates to move from P1 to the retracted position P2.
Conversely, when the opening/closing cover 15 is closed, as shown in FIGS. 1, 9A, 10A, etc., the movement mechanisms 5A and 5B move the exposure device 23 to the retracted position in conjunction with the closing operation. It operates to move from P2 to exposure position P1.

Further, as shown in FIGS. 4, 6, 9 and 10, the moving mechanisms 5A and 5B are provided in the housing 10 of the image forming apparatus 1 as a moving device 17 integrated with the link mechanism 6. ing.
In the first embodiment, as shown in FIGS. 9 and 10, etc., a moving device 17 in which moving mechanism 5 (5A, 5B) and link mechanism 6 (6A, 6B) are integrated is a housing of image forming apparatus 1. Two lateral moving devices 17A and 17B (specifically, the left moving device 17A and the left moving device 17A and the left moving device 17A and the left moving device 17A and the left moving device 17A and the left moving device 17B) are mounted on the upper portions of two side portions (for example, left and right side portions) 113 and 114 of the body 10 facing the longitudinal ends of the exposure device 23. It is mounted as a right moving device 17B).

As shown in FIGS. 4, 8 to 10, etc., the left and right side portions 113 and 114 of the housing 10 are composed of substantially rectangular body portions 113a and 114a and substantially four sides of the body portions are bent outward. It is composed of a member having a shape having bent portions (side bent portions 113b, 114b, upper bent portions 113c, 114c, etc.). Further, the left and right side portions 113 and 114 are provided with cutout portions (not shown) for securing a range of movement by the moving mechanism 5 of the exposure device 23 in the body portion thereof.
Reference numeral 112 in FIG. 4 indicates a bottom portion that is part of the housing 10, and reference numeral 116 indicates an upper connection portion that connects the left and right side portions 113 and 114 with a portion of the upper surface portion.

The moving devices 17A and 17B include first support members 171A and 171B attached to the outer surfaces of the left and right side portions 113 and 114 so as to face the cutout portions (not shown), and the left and right side portions 113 and 171B. , 114 and have second support members 175A, 175B mounted so as to be positioned outside the first support members 171A, 171B.
A part of the moving mechanism 5 (5A, 5B) and a part of the link mechanism 6 (6A, 6B) are placed between the first supporting members 171A, 171B and the second supporting members 175A, 175B. It is
6 to 10, the first support members 171A and 171B are provided with the first guide grooves 53 and the second guide grooves 54 of the moving mechanisms 5A and 5B, respectively. .
In FIG. 6, illustration of the right first support member 171B is omitted. In FIG. 7, only the left first support member 171A is illustrated, and the illustration of the right first support member 171B and the left and right second support members 175A and 175B are omitted.

<Configuration of link mechanism>
As shown in FIGS. 6 to 10 and the like, the link mechanism 6 has two left and right link mechanisms 6A and 6B (specifically, a left link mechanism 6A and a right link mechanism) corresponding to the left movement mechanism 5A and the right movement mechanism 5B. mechanism 6B).
The link mechanisms 6A and 6B include two left and right power input portions 61A and 61B for inputting the rocking motion of the opening/closing cover 15 as power, and the power obtained from each of the power input portions 61A and 61B to the moving mechanism 5. It is provided with two left and right power transmission units 65A and 65B that convert and transmit power for moving motion.

Among them, the power input portions 61A and 61B are, as shown in FIGS. It is composed of two rotating bodies 62A and 62B.
The left rotating body 62A is rotatably supported by the second supporting member 175A of the left moving device 17A so as to exist on the outer surface side of the upper corner of the left side surface 113 facing the opening/closing cover 15. As shown in FIG. The right rotating body 62B is rotatably supported by the second supporting member 175B of the right moving device 17B so as to exist on the outer surface side of the upper corner of the right side surface portion 114 facing the opening/closing cover 15 .

Both of the rotating bodies 62A and 62B are rotatably supported by being fitted into rotating shafts (not shown) respectively provided on the second support member 175A and the right side surface portion 114, as shown in FIGS. 6 to 10 and the like. It has disk-shaped main body portions 620A and 620B on which cylindrical shaft portions 621A and 621B are formed.
As shown in FIGS. 6 to 10, the rotating bodies 62A and 62B are in contact with the contact acting portions 18A and 18B of the opening/closing cover 15 around the shaft portions 621A and 621B of the main body portions 620A and 620B. Contacted portions 622A, 622B and working protrusions 623A, 623B, coupling shafts 624A, 624B coupled to one ends of connecting links 67A, 67B described later, and spring attachments for attaching one ends of tension springs 63A, 63B described later. Portions 625A and 625B are provided.
Further, one ends of tension springs (such as coil springs) 63A, 63B are attached to respective spring attachment portions 625A, 625B of the rotating bodies 62A, 62B, so that they can be rotated in a desired direction with a desired tension (TA, TB). Each one is designed to be pulled continuously.

On the other hand, both the contact acting portions 18A and 18B of the opening/closing cover 15 are arranged upright at predetermined positions on the left and right ends of the inner wall surface of the opening/closing cover 15, as shown in FIGS. a plate-shaped body portion 180 that extends downward toward the tip of the body portion 180; It is composed of a member having a shape having 182.
Further, in both of the contact action portions 18A and 18B, a contact surface portion 183 is provided at the tip of the bent tip portion 181 for contacting and pressing the contact portions 622A and 622B of the rotating bodies 62A and 62B when the open/close cover 15 is closed. is provided.
Furthermore, both of the contact acting portions 18A and 18B are formed by sloping the inner wall surface of the recess portion 182 closer to the contact surface portion 183 downward and outward. It is formed as a drawer slant portion 184 that contacts with the working projections 623A and 623B of the drawer. Moreover, the inner wall surface of the recessed portion 182 on the side opposite to the contact surface portion 183 is formed of a sloped surface that is inclined downward and outward. 623B are formed as slanting surfaces 185 for pressing.

Furthermore, as shown in FIGS. 4 and 8 to 10 , there is an upper portion of the side bent portions 113 b and 114 b of the side portions 113 and 114 of the housing 10 , which moves along with the opening/closing operation of the open/close cover 15 . A passage port 117 is provided for allowing the contact acting portions 18A and 18B to pass therethrough. Further, the rotating bodies 62A and 62B are arranged at positions close to the passage opening 117. As shown in FIG.
Reference numeral 19 in FIG. 4 denotes a flexible connecting part of the opening/closing cover 15 and part of the side bent portion 113b with a predetermined length in order to maintain the posture of the opening/closing cover 15 when opened. It is a member of sexuality.

Next, as shown in FIGS. 7 to 10 and the like, the power transmission units 65A and 65B include two left and right rotary links 66A and 66B that rotate (or swing) in the vicinity of the moving mechanism 5, and a power transmission unit. Two left and right connecting links 67A, 67B that connect parts of the rotating bodies 62A, 62B and parts of the rotating links 66A, 66B in the input parts 61A, 61B, and other parts of the rotating links 66A, 66B. It is composed of two left and right connection links 68A and 68B that connect the first protrusion 51 guided by the first guide groove 53 in the moving mechanism 5. As shown in FIG.

The two left and right rotating links 66A and 66B are plate-like members whose entirety is substantially triangular. The fulcrum shafts 661A and 661B near one top of the rotating links 66A and 66B are inserted into the support grooves 172A and 172B provided in the first support members 171A and 171B of the left moving device 17A and the right moving device 17B. Each is rotatably supported.
Further, when the first coupling shafts 662A and 662B provided near the other top portions of the rotary links 66A and 66B move between two points, the guide grooves 173A provided in the first support members 171A and 171B respectively move. , 173B.

The two left and right connecting links 67A and 67B are elongate plate-like members bent into a desired shape. One end of each connecting link 67A, 67B is rotatably attached to coupling shafts 624A, 624B provided on a part of the rotating bodies 62A, 62B, and the other end of each of the rotating links 66A, 66B is connected to another shaft of the rotating link 66A, 66B. It is rotatably attached to first coupling shafts 662A and 662B provided near the top.

The two left and right connecting links 68A and 68B are plate-like members having a substantially elliptical shape. The connection links 68A, 68B have one end rotatably attached to second coupling shafts 663A, 663B, which are other parts of the rotary links 66A, 66B and are provided near the tops of the other remaining parts. A first protrusion 51 is rotatably attached to the portion. The first projection 51 is attached via a guided portion 681 (FIGS. 6 and 7) guided by the first guide groove 53 in a state where the first projection 51 is fitted.

As shown in FIG. 6, the second support members 175A and 175B have auxiliary first guide grooves of the same shape at positions corresponding to the first guide grooves 53 of the movement mechanisms 5A and 5B provided in the first support members 171A and 171B. Guide grooves 176A and 176B are provided. Guided portions 681A and 681B of the connection links 68A and 68B are fitted into the first auxiliary guide grooves 176A and 176B and are guided in an auxiliary manner.
As shown in FIG. 6, the second support members 175A and 175B have auxiliary support grooves 177A (177B) of the same shape at positions corresponding to the support grooves 172A and 172B provided in the first support members 171A and 171B. is provided. The fulcrum shafts 661A and 661B (auxiliary members 664 for fitting the fulcrum shafts 661A and 661B) of the rotary links 66A and 66B of the link mechanisms 6A and 6B are fitted into the auxiliary support grooves 177A and 177B for auxiliary guidance. be done.

Furthermore, as shown in FIG. 6, the second support member 175A is provided with a fixing attachment portion 178 for attaching and fixing the other end of the tension spring 63A. As shown in FIGS. 8 and 11, the fixed mounting portion 178 is positioned away from the rotating body 62A toward the rotating link 66A and is substantially at the same height in the horizontal direction passing through the rotation center of the rotating body 62A. It is set in a position where
Incidentally, the other end 632b of the tension spring 63B is attached to a fixed attachment portion (not shown) provided on a portion of the body portion 114a of the side portion 114 of the housing 10. As shown in FIG. As shown in FIGS. 9 and 10, this fixed mounting portion (not shown) is located below the rotating body 62B and is located on the opposite side of the rotation center of the rotating body 62B from the rotating link 66B. It is provided in a position shifted so as to

<Detailed Configuration of Moving Device>
The moving devices 17A, 17B (excluding the exposure device 23) provided with the moving mechanisms 5A, 5B and the link mechanisms 6A, 6B are connected to the moving mechanisms 5A, 5B and the power transmission portions 65A, 65B of the link mechanisms 6A, 6B, respectively. It includes two left and right moving device parts 50A and 50B forming a part.

As shown in FIGS. 7, 9 to 11, etc., the moving device portions 50A and 50B have a fulcrum shaft 661 and a second moving device portion which swings about the fulcrum shaft 661 to transmit the force used to move the exposure device 23. Rotating links 66A and 66B having coupling shafts 663, and connections for connecting between the first protrusion 51 and the second coupling shafts 663 of the rotating links 66A and 66B in the mounting member (236) for holding the exposure device 23, which will be described later. It comprises at least links 68A, 68B and a connecting shaft that connects between the mounting member 236 and the connecting links 68, 68B and is guided by the first guide groove 53. As shown in FIG.
Further, the moving device portions 50A and 50B are examples of pressing means for pressing (the exposure main body portion 231 of) the exposure device 23 shown in FIG. A compression spring 237 is included.

In Embodiment 1, the first protrusion 51 fixed to the mounting member 236 is used as the connecting shaft.
Further, in Embodiment 1, the path of the first guide groove 53 and the trajectory of the second coupling shaft 663 of the rotary links 66A and 66B during swinging are in a different relationship. The trajectory of the second coupling axis 663 is an arc curve as indicated by the dashed-dotted line TL in FIG. 11 . The above-mentioned different relationship means that the positions of the path and the trajectory are at least partially different from each other, or that the paths and the trajectory are dissimilar in shape.

The connecting links 68A, 68B in the moving device portions 50A, 50B are connected to the second position when the exposure device 23 is moved to the exposure position P1, as shown in FIGS. 9A, 10A, 11, etc. The connecting shaft 663 stops in the region beyond the straight line connecting the fulcrum shaft 661 and the first projection 51 , and this posture causes the mounting member 236 to react by the biasing force of the compression spring 237 . It is configured to be received and retained from the projection 51 .

11 is a straight line connecting the fulcrum shaft 661 and the first projection 51. A single straight line SL indicated by a one-dot chain line in FIG. Reference numeral 179 in FIGS. 6, 11, etc. indicates a stopping portion which is brought into contact with a portion of the connecting links 68A and 68B and brought to a stopped state when the exposure device 23 is moved to the exposure position P1. . The stopping portion 179 is provided on a part of the second supporting members 175A and 175B, as indicated by dashed lines in FIGS. 6 and 9, for example.

In the moving devices 5A and 5B including the moving device portions 50A and 50B, the above-described tension means as the biasing means biases the rotating links 66A and 66B to swing in the direction G1 in which the exposure device 23 moves to the retracted position P2. Springs 63A and 63B are provided.
The tension springs 63A and 63B generate the forces (biasing forces) MA2 and MB2 that bias the rotary links 66A and 66B when the exposure device 23 is at the exposure position P1, and the forces when the exposure device 23 is at the retracted position P2. It is configured to be weaker than the urging forces (urging forces) MA1 and MB1 (MA2<MA1, MB2<MB1).

The tension springs 63A, 63B are, as shown in FIGS. It is arranged on moving bodies 62A and 62B.
Moreover, when the exposure device 23 is moved from the retracted position P2 to the exposure position P1, part of the tension springs 63A and 63B is the rotation center of the shafts 621A and 621B of the rotating bodies 62A and 62B. are positioned to rest close together until they contain The arrangement of the tension springs 63A, 63B can be realized by selecting fixing positions of both ends of the tension springs 63A, 63B in the longitudinal direction. As a result, the tension springs 63A and 63B are configured such that when the exposure device 23 is at the exposure position P1, the urging force relationship thereof satisfies the above relationship (MA2<MA1, MB2<MB1).

<Detailed Configuration of Exposure Apparatus>
The exposure device 23 attached to the moving mechanisms 5A and 5B includes, as shown in FIGS. It is composed of a holding member 232 that holds the portion 231 and an attachment member 236 for attaching the holding member 232 to the moving mechanisms 5A and 5B. Here, the holding member 232 and the mounting member 236 are configured as holding means for the exposure device 23 .

Both ends 238 of the exposure main body 231 are supported by mounting members 236 so as to be movable (displaceable) in directions indicated by arrows J1 and J2. A light emitting portion 233 configured by an optical element such as a lens that emits light during exposure is arranged on the portion of the exposure body portion 231 opposite to the holding member 232 side.
The holding member 232 is an enclosing frame-shaped member whose cross section is substantially U-shaped and elongated in one direction, and is coupled to the exposure main body 231 via a leaf spring 234 . Reference numeral 235 in FIGS. 12, 13, etc. denotes a fixing screw for fixing the plate spring 234 (the other end side) of which one end side is attached to the exposure main body 231 to the holding member 232 . Reference numeral 239 in FIG. 12 denotes a protective cover that covers and protects portions of the plate spring 234 that are exposed from both ends of the holding member 232 in the longitudinal direction.

The mounting members 236 are plate-like members having a substantially L-shape, and are arranged at both ends of the holding member 232 in the longitudinal direction. The mounting member 236 is provided with a first projection 51 and a second projection 52 protruding outward from its side surface.
Further, the mounting member 236 has a compression spring (which is an example of a pressing means) that presses both end portions 238 of the exposure main body portion 231 against the exposure position P1 (actually, a positioning portion 29 described later) on the lower surface of the top surface portion. A coil spring 237 is provided which is compressed to increase the biasing force.

Further, in the image forming apparatus 1, as shown in FIG. 14, the detachable unit 20 as an example of the detachable means is moved to the exposure position P1 by the exposure device 23 by the moving mechanisms 5A and 5B (or the moving device portions 50A and 50B). A positioning portion 29 is provided that is positioned by contact with a portion of the exposure device 23 when the exposure device 23 is moved. A portion of the exposure device 23 is a portion of both end portions 238 of the exposure main body portion 231 .

The positioning part 29 is a part formed in a desired shape on a part of the supporting member (supporting frame) of the detachable unit 20 . For example, as shown in FIG. 14, the positioning portion 29 is in contact with the photosensitive drum 21 by at least a portion (such as a projecting tip portion) of a lower surface portion 238 a at both end portions 238 of the exposure main body portion 231 of the exposure device 23 . A first positioning portion 29a that performs positioning with respect to the separation distance, and a second positioning portion that is positioned with respect to the angle (attitude) facing the photosensitive drum 21 by contacting at least a portion of one side surface portion 238b at both ends 238 of the first positioning portion 29a. 29b.

In the image forming apparatus 1, as shown in FIG. 15, projections 51 and 52 on the attachment member 236 at both ends of the holding member 232 of the exposure device 23 (exposure main body 231) and compression springs as pressing means are provided. 237 , when the exposure device 23 (both ends 238 of the exposure main body 231 ) contacts the positioning portion 29 and is positioned, it becomes other than the first projection 51 that receives the power for moving the exposure device 23 . The positional relationship is such that the second projection 52 receives the force of being pressed against the second guide groove 54 due to the pressing force F by the spring force of the compression spring 237 .

In the first embodiment, when the exposure main body 231 of the exposure device 23 contacts the positioning portion 29 to position the first protrusion 51 as shown in FIG. It is arranged so as to be guided by the first guide groove 53 and stopped at a position deviated in a direction intersecting the straight line along the acting direction. In this case, the end portion 53b of the first guide groove 53 on the side of the exposure position P1 passes through one side portion of the compression spring 237 so as to approach it, and ends at a position shifted from the one side portion. is formed to

Further, in Embodiment 1, as shown in FIG. It is arranged so as to be guided by the guide groove 54 and stopped at the position on the opposite side of the compression spring 237 . In this case, the guide groove 54 ends so that the end 54b on the side of the exposure position P1 approaches the other (diametrically opposite) side of the compression spring 237 and exists at a shifted position on the other side. formed.

Furthermore, in Embodiment 1, the compression spring 237 is set at least when the exposure main body 231 of the exposure device 23 is in contact with the positioning portion 29 and positioned, as shown in FIG. It is arranged so that a pressing force F having a component f1 in the direction overlapping with the optical axis K acts.

Furthermore, in Embodiment 1, the second projection 52 that receives the force pressed against the second guide groove 54, the mounting member 236 provided with the second projection 52, and the pair of support members provided with the second guide groove 54 are provided. The members 171A and 171B are made of a conductive material such as metal. The housing 10 to which the support members 171A and 171B are attached is made of a conductive material and grounded.

<Moving operation of the exposure device>
The movement operation of the exposure device 23 will be described below.

In the exposure device 23, the link mechanisms 6A, 6B and the moving mechanisms 5A, 5B (and the moving device portions 50A, 50B) of the moving devices 17A, 17B operate in conjunction with the opening and closing operation of the opening and closing cover 15 as described above. , so as to move between the exposure position P1 and the retracted position P2.

◎Movement from exposure position P1 to retreat position P2:
When the exposure device 23 is moved from the exposure position P1 to the retracted position P2, an operation is performed to open the open/close cover 15 which is in a closed state.
At this time, if the opening/closing cover 15 is swung in the direction indicated by the arrow B1 so as to be opened, the contact acting portions 18A and 18B on the opening/closing cover 15 are moved as shown in FIGS. 9(b) and 10(b). comes into contact with the action projections 623A, 623B of the rotating bodies 62A, 62B of the power input parts 61A, 61B in the link mechanisms 6A, 6B, so that the rotating bodies 62A, 62B move as indicated by the dashed arrow C1. start rotating in the indicated direction.
As a result, in the image forming apparatus 1, the power generated by the rotary motion generated by the rotation of the rotating bodies 62A and 62B in the direction indicated by the dashed arrow C1 is transmitted through the power transmission portions 65A and 65B of the link mechanisms 6A and 6B. is transmitted to the moving mechanisms 5A and 5B.

Specifically, when the rotating bodies 62A and 62B rotate in the direction indicated by the dashed arrow C1, the connecting links 67A and 67B of the power transmission units 65A and 65B are moved away from the moving mechanisms 5A and 5B by the dashed arrow D1. The movement of the connecting links 67A, 67B causes the first coupling shafts 662A, 662B of the rotary links 66A, 66B to move along the guide grooves 173A, 173B in the direction indicated by the dashed arrow E1. .
Subsequently, the first coupling shafts 662A and 662B are moved in the direction indicated by the dashed arrow E1, so that the rotary links 66A and 66B move in the direction indicated by the dashed arrow G1 about the fulcrum shafts 661A and 661B. As the rotating links 66A and 66B rotate, the second coupling shafts 663A and 663B also move in the direction indicated by the dashed arrow G1. At this time, the second coupling shafts 663A and 663B move from the lower position to the upper position so as to draw a trajectory including a substantially arcuate curve.
Subsequently, the power generated by the rotary motion when the second coupling shafts 663A and 663B of the rotary links 66A and 66B move (swing) in the direction indicated by the dashed arrow G1 is transmitted through the connection links 68A and 68B to the exposure apparatus. It is transmitted to the first projection 51 at 23 .

As a result, the first projection 51 moves while being guided by the first guide groove 53 in the moving mechanisms 5A and 5B, and moves from a position below the first guide groove 53 to a position above the first guide groove 53. Let me. Along with the movement of the first projection 51, the second projection 52 of the same exposure device 23 moves while being guided by the second guide groove 54 of the moving mechanisms 5A and 5B. position to a position above the second guide groove 54 .

As a result, the exposure device 23 is moved from the exposure position P1 to the retracted position P2 in conjunction with the operation of opening the opening/closing cover 15, as shown in FIGS. 9B and 10B.
At this time, the exposure device 23 moved to the retracted position P2 is kept in a stop posture in which the light emitting portion 233 in the exposure main body portion 231 faces obliquely upward as shown in FIGS. The obliquely upward direction is, for example, an upward direction along the longitudinal direction of the second attachment/detachment passage space S2. Also, the exposure device 23 at this time exists in the narrow space S5 outside the second attachment/detachment passage space S2, as shown in FIG.

Therefore, in the image forming apparatus 1, when the exposure device 23 is moved to the retracted position P2, the attachment/detachment (movement) work of the attachment/detachment unit 20 using the second attachment/detachment passage space S2 is not hindered by the existence of the exposure device 23. becomes possible to do.

◎Movement from retraction position P2 to exposure position P1:
When the exposure device 23 is moved from the retracted position P2 to the exposure position P1, the opening/closing cover 15 in the open state is closed.

At this time, if the opening/closing cover 15 is swung in the direction indicated by the arrow B2 to be closed, the contact action portions 18A and 18B on the opening/closing cover 15 are formed as shown in FIGS. 9(a) and 10(a). After the contact surface portion 183 contacts the contacted portions 622A and 622B of the rotating bodies 62A and 62B of the power input portions 61A and 61B in the link mechanisms 6A and 6B, the rotating bodies 62A and 62B rotate in the direction indicated by the dashed arrow C2. start moving.
As a result, in the image forming apparatus 1, the power generated by the rotational movement of the rotating bodies 62A and 62B rotating in the direction indicated by the dashed arrow C2 is transmitted through the power transmission portions 65A and 65B of the link mechanisms 6A and 6B. is transmitted to the moving mechanisms 5A and 5B.

Specifically, when the rotating bodies 62A and 62B rotate in the direction indicated by the dashed arrow C2, the connecting links 67A and 67B of the power transmission units 65A and 65B move closer to the moving mechanisms 5A and 5B. It is moved in the direction indicated by D2. Thereafter, due to the movement of the connecting links 67A, 67B, the first coupling shafts 662A, 662B of the rotary links 66A, 66B are moved along the guide grooves 173A, 173B in the direction indicated by the dashed arrow E2.
Subsequently, the first coupling shafts 662A and 662B are moved in the direction indicated by the dashed arrow E2, so that the rotary links 66A and 66B move in the direction indicated by the dashed arrow G2 about the fulcrum shafts 661A and 661B. As the rotating links 66A and 66B rotate, the second connecting shafts 663A and 663B also move in the direction indicated by the dashed arrow G2. At this time, the second coupling shafts 663A and 663B move so as to draw a substantially arc-shaped trajectory (one-dot chain line TL in FIG. 11) from the upper position to the lower position.
Subsequently, the power generated by the rotational movement of the second coupling shafts 663A and 663B in the rotary links 66A and 66B when moving in the direction indicated by the dashed arrow G2 is applied to the first joint shafts 663A and 663B in the exposure device 23 via the connection links 68A and 68B. It is transmitted to the protrusion 51 .

As a result, the first protrusion 51 moves while being guided by the first guide groove 53 in the moving mechanisms 5A and 5B, and moves from a position above the first guide groove 53 to a position below the first guide groove 53. Let me. Along with the movement of the first projection 51, the second projection 52 of the same exposure device 23 moves while being guided by the second guide groove 54 of the moving mechanisms 5A and 5B. position to a position below the second guide groove 54 .

As a result, the exposure device 23 is moved from the retracted position P2 to the exposure position P1 in conjunction with the closing operation of the opening/closing cover 15, as shown in FIGS. 9A and 10A.
At this time, the exposure device 23 moved to the exposure position P1, as shown in FIGS. (latent image formation position) and is kept in a stopped posture.

At this time, the exposure device 23 is stopped and held at the exposure position P1 by the following mechanism.

First, as shown in FIG. Parts of both ends 238 (lower surface part 238a and part of side surface part 238b) came into contact with positioning parts 29 (first positioning part 29a and second positioning part 29b) of detachable unit 20, and movement stopped at that point. become a state.

At this time, as shown in FIGS. 9A and 10A, the rotating links 66A and 66B are rotated in the direction indicated by the arrow G2 through the link mechanisms 6A and 6B by the closing operation of the opening/closing cover 15. Since the moving forces FA2 and FB2 continue to be received, the forces FA2 and FB2 are transmitted from the second connecting shafts 663A and 663B to the first protrusion 51 via the connecting links 68A and 68B.
As a result, the mounting member 236 provided with the first protrusion 51 is pressed toward the positioning portion 29 . Further, along with this, the compression spring 237 is further compressed. Therefore, as shown in FIG. 16, the exposure unit 23 is pressed by the compression spring 237 so that the exposure unit 231 is displaced relative to the mounting member 236 in the direction indicated by the arrow J2, and the positioning unit 29 is strongly moved. Since it is pressed, it is firmly positioned.

At this time, the rotation links 66A and 66B continue to rotate in the direction indicated by the arrow G2 via the link mechanisms 6A and 6B due to the closing operation of the opening/closing cover 15, so that the connection links 68A and 68B move toward the positioning portion 29. The attachment member 236 of the exposure device 23 that has come into contact and stopped is in a state of continuing to swing in the direction indicated by the arrow H2 with the first projection 51 as a fulcrum.
As a result, the connecting links 68A and 68B are arranged such that the second connecting shafts 663A and 663B of the rotating links 66A and 66B are connected to the fulcrum shafts 661A and 661B of the rotating links 66A and 66B, respectively, as shown in FIGS. and the first protrusion 51, and touches the stopping portion 179. At that point, it assumes a stopped posture. At this time, the second coupling shafts 663A and 663B pass through the dead point where they intersect the straight line SL. Further, in the rotating links 66A, 66B and the connection links 68A, 68B at this time, the lines connecting the fulcrum shafts 661A, 661B, the second coupling shafts 663A, 663B, and the first protrusions 51 are the second coupling shafts 663A, 663B. The position is deviated from the straight line SL in the direction indicated by the arrow G2 or the arrow H2, and the line is bent in a doglegged shape as a whole.

Subsequently, as shown in FIG. 16, the connection links 68A and 68B at this time generate a reaction (reaction force) on the mounting member 236 due to the pressure force F caused by the spring force of the compression spring 237 at both ends 238 of the exposure main body 231. Fr) from the first projection 51 . Also, the attachment member 236 is pushed back in the direction indicated by the arrow J1 due to this reaction (reaction force Fr).
As a result, the connection links 68A and 68B are maintained in a state in which part of the end portions of the rotary links 66A and 66B on the side connected to the second coupling shafts 663A and 663B are in contact with the stop portion 179, and the above-described stopped state is maintained. Posture is maintained.

In this way, the rotary links 66A and 66B are kept in the stationary posture without rotating in the direction indicated by the arrow H1 by receiving the recoil generated in the mounting member 236 by the pressing force F of the compression spring 237. Therefore, the exposure device 23 is kept in a state in which the exposure main body 231 is kept in contact with the positioning portion 29 of the detachable unit 20, and is stopped at the exposure position P1.

Incidentally, when the rotating links 66A and 66B are kept stopped, the rotating links 66A and 66B do not receive the forces FA2 and FB2 that rotate in the direction indicated by the arrow G2.

That is, at this time, in the link mechanisms 6A, 6B and the moving device portions 50A, 50B, as shown in FIGS. Although the device 23 is in an extended state compared to the retracted position P2, part of the tension springs 63A and 63B is in a state including the rotation center of the shaft portions 621A and 621b of the rotating bodies 62A and 62B. It also approaches and becomes stationary.
Therefore, the tensions TA2 and TB2 of the tension springs 63A and 63B at this time do not act as an urging force to rotate the rotating bodies 62A and 62B in the direction indicated by the dashed arrow C2. in the direction indicated by the dashed arrow C1.
Therefore, at this time, the rotating bodies 62A and 62B receive the tensions TA2 and TB2 of the tension springs 63A and 63B and are rotated in the direction indicated by the arrow C1. , the rotational motion (power) of the rotating bodies 62A and 62B is transmitted by the power transmission portions 65A and 65B as forces FA2 and FB2 that keep rotating the rotating links 66A and 66B in the directions indicated by arrows G2. never.

When the opening/closing cover 15 is completely closed (locked state), the contact acting portions 18A and 18B of the opening/closing cover 15 are positioned in the middle of the recessed portion 182 as shown in FIG. Actuating protrusions 623A and 623B are present on the rotating bodies 62A and 62B, and are kept out of contact with the acting protrusions 623A and 623B.

As shown in FIG. 1, the exposure device 23, which has moved to the exposure position P1 through the above operation process, performs exposure based on image information toward the photosensitive drum 21 during an image forming operation to form an electrostatic latent image. becomes possible.

Then, in the image forming apparatus 1 at this time, as shown in FIGS. 16 and 17, when the exposure device 23 is moved to the exposure position P1, the first protrusion 51 moves toward the end portion of the guide groove 53 as described above. 53b, the attachment member 236 of the exposure device 23 is about to be displaced in the direction indicated by the arrow J1 by receiving the reaction force Fr caused by the pressure force F generated by the compressed spring 237. placed in

As a result, as shown in FIG. 17, the mounting member 236 of the exposure device 23 is rotated in the direction indicated by the arrow M1 with the first protrusion 51 of the mounting member 236 as a fulcrum (rotational axis) due to the reaction force fr. You will continue to receive such power. Further, as a result, the second protrusion 52 of the mounting member 236 continues to receive the force (pressing force) Fp that presses against the second guide groove 54 . As a result, the mounting member 236 is prevented from rotating in the direction indicated by the arrow M2 with the first projection 51 as a fulcrum.

Therefore, in the image forming apparatus 1, when the exposure device 23 is pressed by the compression spring 237 when it is moved to the exposure position P1, it contacts the positioning portion 29 and becomes unstable. is suppressed.
Incidentally, in the image forming apparatus 1, the first protrusion 51, the second protrusion 52, and the compression spring 237 are not arranged in a positional relationship such that the second protrusion 52 receives the force Fp that presses against the second guide groove 54. In this case, due to factors such as tolerances and variations in each component, when the exposure device 23 is positioned as described above, for example, the mounting member 236 may move in the direction indicated by the arrow M2 with the first projection 51 as a fulcrum (second projection 52 (within the width of the second guide groove 54) may move in a rotationally jolting manner, which may result in unstable positioning and poor reproducibility.

Further, the image forming apparatus 1 is less likely to become unstable due to rattling at the stage where the exposure device 23 is moved to the exposure position P1 by contacting the positioning portion 29 as described above. , the exposure can be stably carried out in a fixed posture, and good latent image formation becomes possible.
Therefore, according to the image forming apparatus 1, even if the exposure device 23 is configured to be movable between the exposure position P1 and the retracted position P2, the exposure device 23 can perform good latent image formation and stabilize. Image formation with high image quality becomes possible.

Further, in the image forming apparatus 1, as shown in FIG. 15, the first projection 51 is located at a position deviated in a direction intersecting the straight line along the direction in which the pressing force F of the compression spring 237 acts as described above. 1 Guide groove 53 guides and stops. Therefore, the mounting member 236 of the exposure device 23 is likely to receive a force that rotates the mounting member 236 of the exposure device 23 in the direction indicated by the arrow M1 with the first protrusion 51 as a fulcrum. The two projections 52 are also likely to receive the force Fp pressed against the second guide grooves 54 .
Therefore, according to the image forming apparatus 1, the exposure device 23 contacts the positioning portion of the exposure position in comparison with the case where the first projection 51 is not arranged in the positional relationship described above with respect to the compression spring 237. Unstable rattling at the stage of being positioned is more accurately suppressed.

Further, in the image forming apparatus 1, as shown in FIG. 15, the second protrusion 52 is guided by the guide groove 54 to the position opposite to the first protrusion 51 with the compression spring 237 interposed therebetween. configured to be stopped. Therefore, when the mounting member 236 of the exposure device 23 receives a force that rotates the mounting member 236 of the exposure device 23 about the first projection 51 in the direction indicated by the arrow M1 by the reaction force fr, the force acts as the second guiding force of the second projection 52 . It becomes easy to be reflected as the force Fp pressed against the groove 54 .
Therefore, according to the image forming apparatus 1, the second projection 52 is positioned in the second guide direction as compared with the case where the second projection 52 is not arranged with respect to the compression spring 237 and the first projection 51 in the positional relationship described above. The state of receiving the force Fp pressed against the groove 54 can be easily kept stable, and the exposure device 23 can be more reliably prevented from becoming unstable due to rattling at the stage of being positioned.

Moreover, in the image forming apparatus 1, as shown in FIG. 15, the compression spring 237 is arranged so that the pressing force F having the component f1 in the direction overlapping the optical axis K of the exposure device 23 acts. ing. Therefore, the pressing force F of the compression spring 237 effectively acts as a force for pressing (the exposure main body 231 of) the exposure device 23 against the positioning portion 29, thereby stably fixing the exposure device 23 at the exposure position P1. Become so.
Therefore, according to this image forming apparatus 1, compared to the case where the compression spring 237 is not arranged so as to apply a pressing force having a component in the direction overlapping the optical axis K of the exposure device 23, the exposure device 23 is It contacts the positioning portion 29 of the exposure position P1, is effectively positioned and fixed, and is also prevented from rattling and becoming unstable at the positioned stage.

Further, in the image forming apparatus 1, as described above, the second protrusion 52, the mounting member 236, and the pair of support members 171A and 171B are made of a conductive material. For this reason, the mounting member 236 that holds the exposure main body 231 of the exposure device 23 is in a state where the second projections 52 are pressed against the second guide grooves 54 of the pair of support members 171A and 171B and are in reliable contact. Through the pair of support members 171A and 171B, a conductive state is established with the housing 10 which is grounded.
Therefore, according to the image forming apparatus 1, compared to the case where the second projection 52, the mounting member 236, and the pair of support members 171A and 171B are made of a non-conductive material, the A stable grounding process of the exposure main body 231 of the exposure device 23 when moved to the exposure position P1 is realized without adding components for grounding process.

[Embodiment 2]
FIG. 18 shows part of an image forming apparatus according to Embodiment 2 of the present invention.
The image forming apparatus according to the second embodiment includes one guide groove 55 as a guide groove for guiding the first protrusion 51 and the second protrusion 52 so as to move the exposure device 23 between the exposure position P1 and the retracted position P2. The configuration of the image forming apparatus 1 is the same as that of the image forming apparatus 1 according to the first embodiment, except that it is changed to .

As shown in FIG. 18, the single guide groove 55 is a guide groove that curves in an arc between the exposure position P1 and the retracted position P2. This guide groove 55 is formed in each of the pair of support members 171A and 171B.
Also, the exposure device 23 is mounted so that both the first projection 51 and the second projection 52 on the mounting member 236 are guided by one guide groove 55, as shown in FIG. Further, the power FA at the time of movement from the moving mechanism 5 and the link mechanism 6 that operate in conjunction with the opening/closing operation of the opening/closing cover 15 is the same as in the case of the moving structure of the exposure device 23 in the first embodiment. 51 (optionally via connecting link 68).

Also in the image forming apparatus according to the second embodiment, the protrusions 51 and 52 on the mounting member 236 of the exposure device 23 (exposure main body 231) and the compression spring 237 as a pressing means are connected to the exposure device 23 (of the exposure device 23). When both ends 238 of the exposure main body 231 are brought into contact with the positioning portion 29 and positioned, the second projections 52 other than the first projections 51 that receive the power for moving the exposure device 23 are the compression springs 237. They are arranged in such a positional relationship that they are subjected to the force of being pressed against the guide groove 55 due to the pressing force F caused by the spring force. A specific arrangement configuration is the same as the arrangement configuration in the first embodiment.
In this image forming apparatus, as shown in FIG. 18, the compression spring 237 is set at least when the exposure main body 231 of the exposure device 23 is in contact with the positioning portion 29 and positioned. It is arranged so that a pressing force F having a component f2 in a direction parallel to the optical axis K acts.

Further, in this image forming apparatus, as shown in FIG. 19, when the exposure device 23 is moved to the exposure position P1, the first protrusions 51 are pulled out in substantially the same manner as in the image forming apparatus 1 according to the first embodiment. does not reach the end 55b of the guide groove 55, while the mounting member 236 of the exposure device 23 receives the reaction force Fr caused by the pressure force F generated by the compressed spring 237, indicated by the arrow J1. It is placed in a state of trying to displace in the direction.

19, the mounting member 236 of the exposure device 23 is rotated in the direction indicated by the arrow M1 with the first projection 51 of the mounting member 236 as the fulcrum due to the reaction force fr. will continue to receive As a result, the second protrusion 52 of the mounting member 236 continues to receive the force Fp pressed against the guide groove 55 . As a result, the attachment member 236 is prevented from rotating in the direction indicated by the arrow M2 with the first projection 51 as a fulcrum.

Therefore, in this image forming apparatus as well, when the exposure device 23 is pressed by the compression spring 237 when it is moved to the exposure position P1, it comes into contact with the positioning portion 29 and becomes unstable. is similarly suppressed.

[Embodiment 3]
FIG. 20 shows part of an image forming apparatus according to Embodiment 3 of the present invention.
The image forming apparatus according to Embodiment 3 has the same configuration as that of the image forming apparatus according to Embodiment 2, except that the guide groove 55 is replaced with a guide groove 56 having a different shape. is.

As shown in FIG. 20, one guide groove 56 is a guide groove that bends once between the exposure position P1 and the retracted position P2. This guide groove 56 is also formed in the pair of support members 171A and 171B.
Also, the exposure device 23 is mounted so that both the first projection 51 and the second projection 52 on the mounting member 236 are guided by one guide groove 56, as shown in FIG. At this time, the power FA at the time of movement from the moving mechanism 5 and the link mechanism 6 that operate in conjunction with the opening/closing operation of the opening/closing cover 15 is applied to the first projection 51 as in the case of the exposure device 23 in the second embodiment. configured to be communicated (optionally via connecting link 68).

Also in the image forming apparatus according to the third embodiment, the second projections 52 are located between the projections 51 and 52 on the mounting member 236 of the exposure device 23 (exposure body portion 231) and the compression spring 237 as the pressing means. The projections 51 and 52 and the compression spring 237 are arranged in the same positional relationship as in the first and second embodiments except that they are arranged on the same side with the compression spring 237 interposed therebetween.
Also in this image forming apparatus, as shown in FIG. 20, the compression spring 237 of the exposure device 23 is at least exposed when the main body portion 231 of the exposure device 23 is in contact with the positioning portion 29 and positioned. is arranged so that a pressing force F having a component f2 in a direction parallel to the optical axis K at is applied.

Further, in this image forming apparatus, as shown in FIG. 21, when the exposure device 23 is moved to the exposure position P1, the first protrusion 51 is moved to the position P1 in substantially the same manner as in the image forming apparatus according to the second embodiment. While stopping at a position not reaching the end portion 55b of the guide groove 55, the mounting member 236 of the exposure device 23 receives the reaction force Fr caused by the pressure force F generated by the compressed spring 237, and the direction indicated by the arrow J1. It is placed in a state of trying to displace to

21, the mounting member 236 of the exposure device 23 is rotated in the direction indicated by the arrow M1 with the first protrusion 51 of the mounting member 236 as a fulcrum due to the reaction force fr. will continue to receive As a result, the second projection 52 of the mounting member 236 continues to receive the force Fp pressed against the guide groove 56 . As a result, the attachment member 236 is prevented from rotating in the direction indicated by the arrow M2 with the first projection 51 as a fulcrum.

Therefore, in this image forming apparatus as well, when the exposure device 23 is pressed by the compression spring 237 when it is moved to the exposure position P1, it comes into contact with the positioning portion 29 and becomes unstable. is similarly suppressed.

[Modification]
The present invention is not limited to the configurations of Embodiments 1 to 3 above, and the configuration can be changed within the scope of not changing the gist of the invention described in the scope of claims. includes.

In Embodiments 1 to 3, the compression spring 237 as the pressing means is arranged so that the pressing force F having the component f1 in the direction overlapping the optical axis K of the exposure device 23 acts, and the first projection 51 is arranged by the compression spring 237. 1 shows a configuration example in which it is guided by the first guide groove 53 (or 55, 56) and stopped at a position deviated in the direction intersecting with the straight line along the direction in which the pressing force F acts.
However, in the present invention, as shown in FIG. 22, the first projection 51 is arranged so as to be guided by the first guide groove 53 (or 55, 56) and stopped at the position on the optical axis K of the exposure device 23. However, it is also possible to arrange the compression spring 237 at a position shifted in the direction intersecting the optical axis K of the exposure device 23 . However, in such a configuration, for example, the light output portion 233 (strictly speaking, the optical axis K) of the exposure device 23 is positioned relative to both ends 238 of the exposure main body portion that are in contact with the positioning portion 29 of the holding member 232 . It can be applied to the case of using an exposure apparatus configured such that it is arranged in a displaced state (asymmetrical state) in the rotational direction of .

Even in this configuration, when the exposure device 23 is moved to the exposure position P1, the second protrusion 52 on the mounting member 236 of the exposure device 23 is pressed against the corresponding guide groove 56 as shown in FIG. It will be in a state where it continues to receive the force Fp.
Therefore, in this image forming apparatus as well, when the exposure device 23 is pressed by the compression spring 237 when it is moved to the exposure position P1, it comes into contact with the positioning portion 29 and becomes unstable. is similarly suppressed.

Further, in Embodiments 1 to 3, configuration examples are shown in which the moving device 17 including the moving mechanism 5 and the link mechanism 6 is applied as power means for generating and transmitting power for moving the exposure device 23. , as the power means, means having other configurations may be applied. Even in that case, the power from the power means is configured to be transmitted to one of the plurality of projections (51, 52, etc.) on the exposure device 23. FIG.

Further, in Embodiments 1 to 3, the configuration example in which the exposure device 23 is moved to the retracted position P2 as the non-exposure position has been shown, but the non-exposure position may be another single or a plurality of positions. . In this case, it may be necessary to change (change the number, shape, etc.) other components such as guide grooves and projections in accordance with the non-exposure position.

In addition, in Embodiments 1 to 3, an image forming apparatus that forms a color image using an intermediate transfer method is exemplified as an image forming apparatus. However, the image forming apparatus according to the present invention may be any other type of image forming apparatus as long as it is necessary to move the exposure device 23 between the exposure position P1 and the non-exposure position such as the retracted position P2. It is applicable even if there is

1 ... Image forming apparatus 5 ... Moving mechanism (a part of an example of power means)
6 ... link mechanism (a part of an example of power means)
15... Opening and closing cover (a part of an example of power means)
23 ... Exposure device (an example of exposure means)
29... Positioning part 51... First protrusion (an example of protrusion)
52...Second projection (an example of projection)
53... First guide groove (an example of a guide groove)
54 Second guide groove (an example of a guide groove)
171A, 171B... Left and right first support members (an example of a pair of support means)
232... Holding member (a part of an example of holding means)
236 ... Mounting member (a part of an example of holding means)
237 Compression spring (an example of pressing means)
P1... Exposure position P2... Retreat position (an example of non-exposure position)
F … Pressing force FA1, FA2 … Power (a part of the power when moving)
Fp... Pushing force K... Optical axis line

Claims (7)

holding means for holding exposure means for forming a latent image and having a plurality of projections at both ends in the longitudinal direction;
a pair of support means each provided with a guide groove for guiding the plurality of protrusions so as to move the exposure means to an exposure position and a non-exposure position;
a positioning unit that contacts and positions the exposure unit when the exposure unit is moved to the exposure position;
pressing means for pressing the exposure means so as to press the exposure means against the positioning portion;
power means for generating and transmitting power for moving the exposure means to one of the plurality of projections;
with
The plurality of projections on both ends of the holding means and the pressing means are, when the exposure means is positioned by coming into contact with the positioning part, the projections other than the projections receiving the power for the movement among the plurality of projections. One of the image forming apparatuses is arranged in a positional relationship such that one of them receives the force of being pressed against the guide groove due to the pressing force of the pressing means. Of the plurality of projections, the projection that receives the power when moving intersects with a straight line along the direction in which the pressing force of the pressing means acts when the exposure means contacts the positioning portion and is positioned. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is arranged so as to be guided by the guide groove and stopped at a position shifted in the direction. One of the plurality of projections other than the projection receiving the power when moving is the projection receiving the power when moving when the exposure means is positioned in contact with the positioning portion. 3. The image forming apparatus according to claim 2, wherein the image forming apparatus is arranged so as to be guided by the guide groove and stopped at a position on the opposite side of the pressing means. 4. The image forming apparatus according to any one of claims 1 to 3, wherein the pressing means is arranged to apply a pressing force having a component in a direction overlapping with an optical axis line in exposure of the exposing means. The holding means is provided with two protrusions at both ends thereof,
5. The image forming apparatus according to claim 1, wherein each of said pair of support means is provided with two or more guide grooves for individually guiding said two projections. The exposing means is held by the holding means in a displaceable state toward the positioning portion,
6. The image forming apparatus according to claim 1, wherein said pressing means is arranged between said holding means and said exposing means. 7. The image forming method according to any one of claims 1 to 6, wherein the projection pressed against the guide groove, the holding means, and the pair of supporting means among the plurality of projections are made of a conductive material. Device.

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