JPH0822705B2 - Image generation device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image generating apparatus such as an electrostatic copying apparatus and an apparatus such as an image generating apparatus that conveys a sheet member through a conveying path and then discharges the sheet member to a receiving portion.

<Prior Art> Conventionally, an electrostatic copying apparatus, which is an example of an image generating apparatus, includes a copy paper supply unit that supplies copy paper and a copy paper conveyance path that conveys the copy paper supplied from the copy paper supply unit. Thus, an image is generated on the surface of the copy paper supplied from the copy paper supply means while being transferred through the copy paper transfer path. Various detecting means for detecting the copy paper are arranged in the copy paper conveying path, and signals from these detecting means are used to control the apparatus or detect a jam of the copy paper.

However, in the conventional apparatus, the detection means is configured to directly detect the copy paper, and therefore there are the following problems to be solved. That is, in order to detect a copy sheet, it is necessary to dispose the above-mentioned detection means at this detection portion. Therefore, the position where the detection means is disposed is limited, and the above-mentioned detection means is provided at a portion where a relatively small space exists. It becomes difficult to provide the detecting means, and the copy paper cannot be detected at the above-mentioned portion.

<Objects of the Invention> The present invention has been made in view of the above facts, and an object of the present invention is to reliably detect a sheet member with a relatively simple structure even in a portion having a relatively small space. An object is to provide an image generation device.

<Summary of the Invention> According to the present invention, in order to achieve the above object, a sheet member supplied from a supply unit is conveyed through a conveyance path, and an image is formed on the surface while the sheet member is conveyed through the conveyance path. , An image generating apparatus in which a detection mechanism for detecting a sheet member is disposed in the conveyance path; the detection mechanism is a detected member that is moved by the action of the sheet member, and a detection unit that detects the detected member. Equipped with
An image forming apparatus is provided in which the detected means also functions as a guide means for guiding the sheet member to the downstream side.

<Preferred Embodiments of the Invention> Hereinafter, the present invention will be described with reference to the accompanying drawings by applying it to a laser beam printer as an example of an image generating apparatus.

Outline of Laser Beam Printer In FIG. 1, which is a simplified cross-sectional view of a laser beam printer, the illustrated laser beam printer includes a housing 2 having a rectangular parallelepiped shape. As shown in FIG. 1, the housing 2 is defined by various outer covers 2a, 2b, 2c, 2d, 2e and 2f made of synthetic resin material.

A process unit 4 is arranged at a substantially central portion of the housing 2. The illustrated process unit 4 includes a unit frame 6 which is detachably mounted in the housing 2, and a rotary drum 8 is rotatably mounted in the unit frame 6. An electrostatic photoconductor is provided on the peripheral surface of the rotary drum 8. Around the rotating drum 8 which is rotated in the direction indicated by the arrow 10, a charging corona discharger 12 and a developing device 1 are provided.
4. A transfer corona discharger 16 and a cleaning device 18 are arranged, and a charging corona discharger 12, a developing device 14 and a cleaning device 18 are mounted on the unit frame 6. The charging corona discharger 12 charges the photoconductor on the rotary drum 8 to a specific polarity. The developing device 14 includes a magnetic brush mechanism 20,
The electrostatic latent image formed as described below is developed into a toner image. Further, the corona discharger 16 for transfer applies corona discharge to the back surface of the sheet member conveyed through the conveying path as described later. The cleaning device 18 includes an elastic blade 22 that acts on the surface of the photoconductor to remove toner remaining on the surface of the photoconductor.

An optical unit 24 is arranged in the upper part of the housing 2, that is, above the process unit 4. The illustrated optical unit 24 includes a box-shaped unit housing 26, and in the housing 26, a laser light source (not shown), a rotary polygon mirror 28 which is rotated in a predetermined direction, and a first imaging lens. 30, second imaging lens 32, first reflecting mirror 34, second
The reflecting mirror 36 and the cylindrical lens 38 are arranged. A laser light source (not shown) irradiates the rotary polygon mirror 28 with laser light based on image information output from a computer, for example. The laser light reflected from the rotating polygon mirror 28 is
As shown by the alternate long and short dash line in the figure, the first imaging lens 30 and the second imaging lens 30
To the first reflecting mirror 34 through the image forming lens 32, is reflected by the first reflecting mirror 34 and the second reflecting mirror 36, and further passes through the cylindrical lens 38 to rotate in the projection area 40. It is projected on the surface of the drum 8.

In the lower part of the housing 2, that is, below the process unit 4, a transport mechanism generally designated by the numeral 42 is arranged. The illustrated transport mechanism 42 includes a transport roller pair 44, a guide plate 46, a guide plate 48, a fixing roller pair 50, a guide claw 52, and a transport roller pair 54.
And a conveyance path for conveying a sheet member such as a recording sheet is defined by these. In the specific example, the upstream end of the transport path is branched into two, one of which extends linearly to the right, the manual supply means 56 is provided at the upstream end, and the other is An automatic supply means 58 is provided at the upstream end (more specifically, below the transport mechanism 42 and at the bottom of the housing 2) of the curved extension. In the case of using the manual supply means 56, the illustrated manual supply means 56 is provided with a table 60 which is rotatable between a supply position shown in FIG. 1 and a storage position (not shown) which is rotated upward. The table 60 is positioned at the supply position. When the sheet member is positioned on the table 60 and inserted through the opening 62 formed in the right wall surface of the housing 2, the sheet member is attached to the lower surface of the guide plate 64 and the exterior cover.
It is guided to the conveying roller pair 44 through between the upper edges of the guide ridges 66 provided on the inner surface of 2b. Also, the illustrated automatic supply means
The 58 includes a cassette 68 in which the sheet members are loaded in a stacked state. The cassette 68 is detachably attached to a cassette receiving portion 72 defined on the bottom of the housing 2 through an opening 70 formed on the left wall surface of the housing 2.
A feeding roller 74 is arranged above the cassette receiving portion 72. Therefore, when the feeding roller 74 is rotated in the direction shown by the arrow 76, the sheet member in the cassette 68 is moved by one.
The sheet member sent out sheet by sheet is sent to the exterior cover.
Guide ridge 78 and exterior cover 2b provided on the upright wall of 2a
Is guided by the guide ridge 66 and guided to the conveying roller pair 44.

The downstream end of the transport path is also branched into two,
In connection with this, the exterior cover 2f is further selectively positioned at a first position shown by a chain double-dashed line in FIG. 1 and a second position shown by a solid line in FIG. Exterior cover 2f
Is in the first position, the sheet member sent from the pair of transport rollers 54 is directly discharged to the outside of the housing 2 and received by the inner surface of the outer cover 2f (the upper surface in the state indicated by the chain double-dashed line) (hence, The outer cover 2f functions as the first receiving portion). On the other hand, the outer cover 2f is the second
In the position of, the sheet member delivered from the pair of transport rollers 54 is further transported to the upper side, and by the action of the pair of discharge rollers 78, the receiving portion 80 defined on the upper surface of the housing 2 (functions as a second receiving portion). ) Is discharged to.

The operation of the above laser beam printer will be outlined below.

While the rotating drum 8 is rotated in the direction shown by the arrow 10, the charging corona discharger 12 charges the photosensitive member of the rotating drum 8, and then the laser light source (not shown) of the optical unit 24 in the projection area 40. The laser light from is projected on the photoconductor,
Thus, an electrostatic latent image corresponding to image information is formed on the surface of the photoconductor. Thereafter, the magnetic brush mechanism 20 of the developing device 14 applies toner to the electrostatic latent image on the photoconductor to develop the electrostatic latent image into a toner image. Next, the sheet member supplied to the conveying path from the manual supply unit 56 or the automatic supply unit 58 is brought into contact with the photosensitive member, and the toner image on the photosensitive member is transferred to the sheet member by the action of the transfer corona discharger 16. . The sheet member on which the toner image is transferred is separated from the rotary drum 8,
Next, the toner image is conveyed to the fixing roller pair 50, and the toner image is fixed on the surface of the sheet member by the action of the fixing roller pair 50.
The sheet member on which the toner image has been fixed is conveyed to the conveying roller pair 54, and when the outer cover 2f is in the first position, it is directly discharged onto the outer cover 2f. When the sheet member is discharged onto the exterior cover 2f, as understood from FIG. 1, the sheet member is discharged with the surface on which the image is formed facing up. On the other hand, when the exterior cover 2f is in the second position, the sheet member conveyed to the conveying roller pair 54 is conveyed further upward and then the receiving portion 80 on the housing 2 by the action of the discharge roller pair 78. Is discharged to. When the sheet member is discharged onto the receiving portion 80, as can be seen from FIG. 1, the sheet member is discharged with the surface on which the image is formed facing down, and therefore, the page alignment of the discharged sheet member is performed. You don't have to do it later. On the other hand, the rotary drum 8 continues to rotate further, and the cleaning device 18 acts to remove the residual toner from the surface of the photoconductor.

Configuration near the upstream end of the transport path Next, the configuration near the upstream end of the transport path will be described in detail with reference to FIG. 1 and FIG.

One of the branches at the upstream end of the transport path (manual supply means
The first detection mechanism 82 is provided on one side (connected to 56). The first detection mechanism 82 includes a detection switch 84 which can be composed of, for example, a reed switch,
The detection arm 86 of the detection switch 84 projects through the notch 88 formed in the guide plate 64 to the above-mentioned one of the upstream ends of the transport path. Therefore, when a sheet member is inserted from the table 60 through the opening 62, the sheet member acts on the detection arm 86, and thus the detection switch 84 is changed from the open state to the closed state.

A second detection mechanism 90 is arranged at the other branched end (the other end connected to the automatic supply means 58) at the upstream end of the transport path. The second detection mechanism 90 of the specific example includes an optical detection unit 92 that can be configured by, for example, a photo interrupter, and a detected member 94 that is detected by the optical detection unit 92. Mainly referring to FIG. 2, the detected member 94 is substantially L-shaped, and the acting portion 96 extending rightward in FIG. 2 and the detected portion 98 extending upward in FIG.
have. The detected member 94 is rotatably mounted on the rotary shaft 100 on which the feed roller 74 is mounted, and is shown in FIG. 1 at the first position shown by the solid line and in FIG. 2 at the two-dot chain line. It is swingable between the second position and the second position. The optical detecting means 92 is composed of a combination of a light emitting element and a light receiving element, and the light from the light emitting element is received by the light receiving element. This optical detecting means 92 has a rotating shaft 100.
Is attached to a mounting member 102 provided adjacent to. In the second detection mechanism 90, when the detected member 94 is positioned at the second position, the detected portion 98 is located between the light emitting element and the light receiving element of the optical detecting means 92, and thus the light emitting element. The light from is blocked by the detected part 98.

The detected member 94 is further configured as follows. That is, the acting portion 96 of the detected member 94 also functions as a guide means for guiding the sheet member, and extends to the right in FIG. 2 to define the other branched side of the upstream end of the conveying path. There is. The other side of the upstream end of the transport path is provided with a guide ridge 78 provided on the upright wall portion of the exterior cover 2a (the guide ridge 78 is perpendicular to the paper surface in FIGS. 1 and 2). A plurality of guide ridges 66 are provided at the upper edge of the outer cover 2b and a plurality of such guide ridges 66 provided at intervals in the width direction. (Provided). Then, the leading edge of the action portion 96 of the detected member 94 extends upward in an arc shape so that the sheet member sent from the cassette 68 is surely guided to the nip portion of the conveying roller pair 44, and the guide ridge 78 is provided. The upper edge of the guide ridge 66 and the upper edge of the guide ridge 66 also extend in an arc shape toward the nip portion of the transport roller pair 44.

The operation control by the first detection mechanism 82 and the second detection mechanism 90 is performed as follows.

When the sheet member is supplied by using the manual supply means 56, the operation of the pair of transport rollers 44 is controlled by the first detection mechanism 82. That is, when a sheet member is positioned on the table 60 and inserted into the housing 2 through the opening 62, the detection switch 84 detects this sheet member and enters a closed state.
After a lapse of a predetermined first time from such detection, the conveyance roller pair 44
Is rotated in the direction indicated by the arrow for a certain short time. The first
The time may be somewhat longer than the time required to insert from the detection arm 86 of the detection switch 84 to the nip portion of the transport roller pair 44, for example, so that the tip of the sheet member manually inserted stops. The sheet is brought into contact with the nip portion of the pair of conveying rollers 44, thereby correcting the inclination of the sheet member and preventing the oblique feeding. Further, the fixed short period of time is sufficient for moving the leading edge of the sheet member, which is in contact with the nip portion of the conveying roller pair 44, to a position where it slightly protrudes through the nip portion. By rotating 44, the leading end of the sheet member is securely nipped by the pair of transport rollers 44. After the conveying roller pair 44 has thus rotated, it stops. Then, by pressing a start switch (not shown), the pair of transport rollers 44 is rotated again, and the transport of the sheet member is started. Then, the sheet member is conveyed so that the detection switch
When 104 detects this sheet member, projection of laser light containing image information on the surface of the rotating drum 8 rotating in the direction indicated by the arrow 10 is started, whereby the rotating drum 8
The timing of the toner image formed on the sheet member and the sheet member conveyed through the conveying path are adjusted.

When the sheet member is supplied using the automatic supply means 58, the operation of the pair of conveying rollers 44 is controlled by the second detection mechanism 90. That is, in such a case, the start switch (not shown) is pressed. Then, the feeding roller 74 is indicated by an arrow.
The sheet member that is rotated in the direction indicated by 76 and is accommodated in the cassette 68 is delivered by the action of the feeding roller 74, and the sheet member thus delivered is the operating portion of the detected member 94.
It is curved upward through a gap between 96 and the upper edge of the guide protrusion 78, and is guided by the guide protrusion 66 to be guided to the nip portion of the conveying roller pair 44. When the sheet member is guided to the pair of transport rollers 44, the sheet member acts on the acting portion 96 of the detected member 94 and lifts it upward, so that the detected member 94 is at the first position (the detected member 94 is its own weight). 2 is displaced clockwise in FIG. 2 and is held in the first position by contacting the upper end of the vertical wall portion of the exterior cover 2a with the tip end portion of the normal action portion 96) to the second position. Positioned. Thus, the optical detecting means 92 detects the sheet member through the detected member 94 by the detected portion 98 blocking the light from the light emitting element, and the optical detecting means 92 is closed. . In the specific example, the conveying roller pair 44 is rotated after a predetermined second time has elapsed after the optical detecting unit 92 detects the sheet member. The second time may be, for example, somewhat longer than the time required for the leading edge of the sheet to be conveyed to the nip portion of the shipping roller pair 44 after the optical detection unit 92 detects the sheet member, and is set by such setting. , The leading edge of the sheet member fed from the cassette 68 is stopped.
The sheet member is brought into contact with the nip portion of the sheet member, and thereby the inclination of the sheet member is corrected. Then, when the conveying roller pair 44 rotates after the second time has elapsed, the conveyance of this sheet member is started, and the detection switch 104 detects the sheet member that has started conveyance, so that image information is included in the same manner as described above. The projection of the laser light is started, and thereby the timing of the toner image formed on the rotary drum 8 and the sheet member conveyed through the conveying path is adjusted.

In the illustrated specific example, since the action portion 96 of the detected member 94 defines a part of the conveyance path, the guide plate and the like can be partially omitted to simplify the configuration of the apparatus. Also, in a specific example,
The detected member 94 is a rotary shaft on which the feeding roller 74 is mounted.
Since it is attached to 100, the configuration of the second detection mechanism 90 can be simplified, and the action portion 96 of the detected member 94 can be further simplified.
With this, the sheet member sent out from the cassette 68 can be reliably guided toward the nip portion of the conveying roller pair 44. The detected member 94 can be rotatably mounted on a shaft member separate from the rotary shaft 100.

In the illustrated specific example, a first detection mechanism 82 is disposed on one of the branched ends of the upstream end of the transport path, and a second detection mechanism 90 is disposed on the other branched end. However, a common detection mechanism can be used when both of the two branches described above are present in close proximity. Although not shown, for example, a single detection switch may be arranged above the two branched paths, and the detection arm of this detection switch may be made to project through the one path to the other path. . With such a configuration, the detection switch detects the sheet member supplied from the manual supply means, and also detects the sheet member supplied from the automatic supply means, and thus the detection means of the detection means is compared with the specific example shown in the drawing. The number can be small, and the configuration can be simplified and provided at low cost.

Configuration near the downstream end of the transport path Next, the configuration near the downstream end of the transport path will be described in detail with reference to FIG. 1 and FIG.

In the illustrated specific example, the path that branches from the pair of transport rollers 54 and extends upward (the branched one at the downstream end of the transport path) is the inner surface of the exterior cover 2d, as understood from FIG. It is defined by the inner surface of the outer cover 2f. On the inner surface of the outer cover 2d, a plurality of guide ridges 106 extending in the vertical direction in FIG. 1 are arranged at intervals in the width direction (direction perpendicular to the paper surface in FIG. 1, lower left to upper right direction in FIG. 3). It is provided. Further, on the inner surface of the outer cover 2f, a plurality of guide ridges 108 extending in the vertical direction in FIG. 1 are provided at intervals in the width direction. Therefore, the sheet member passing through such a path (that is, between the exterior covers 2d and 2f) is guided upward by the guide protrusions 106 and 108, and is further protruded on the inner surface of the exterior cover 2e. It is guided by 110 and the upper edge of the guide protrusion 106, and is guided to the nip portion of the discharge roller pair 78.

In the specific example, holes for cooling are formed in the exterior covers 2d and 2f. That is, in the exterior cover 2d, a plurality of cooling holes 112 are formed at intervals between the guide ridges 106 in the vertical direction at intervals. Also in the exterior cover 2f, a plurality of cooling holes 114 are formed at intervals between the guide ridges 108 at intervals in the vertical direction. With such a configuration, the sheet member conveyed between the exterior covers 2d and 2f (when the toner image on the sheet member is heated and fixed by the fixing roller pair 50, the toner is applied by the heat applied when the toner image is fixed. The members are also heated considerably), and the holes 112 and 114 formed in the exterior covers 2d and 2f.
The sheet member cooled effectively by the air flowing therethrough is discharged to the receiving portion 80. In the specific example, since the guide protrusions 106 and 108 are provided on the inner surfaces of the outer covers 2d and 2f as described above, the sheet member substantially closes the holes 112 and 114 formed in the outer covers 2d and 2f. However, the sheet member is always cooled.

The receiving portion 80 provided on the upper surface of the housing 2 is defined by the outer surface of the inclined portion of the outer cover 2c and the outer surface of the outer cover 2d. The exterior cover 2d has a pair of discharge rollers 78
1 extends somewhat to the left in FIG. 1 in the vertical direction. Further, the inclined portion of the outer cover 2c is inclined upward to the right in FIG. 1, and the lower end of the inclined portion is connected to the lower end of the outer cover 2d.
The receiving portion 80 (specifically, the receiving surface) is directed from one end to the other end, that is, rightward in FIG. 1, in order to receive the sheet members discharged from the discharge roller pair 78 in a laminated state as required. And is preferably inclined upwards about 45 degrees. Further, in order to discharge the sheet member to the receiving portion 80 as required by the action of the discharge roller pair 78, the discharge roller pair 78 discharges the sheet member upward at an angle of about 10 to 15 degrees from the horizontal direction. Preferably. With this structure, the sheet member discharged from the pair of discharge rollers 78 to the receiving portion 80 moves downward on the inclined portion of the exterior cover 2c, and thus to the lower left in FIG. 2, and its rear end is the exterior cover. By abutting the outer surface of 2d, it is received in a laminated state as indicated by reference numeral 118 in FIG.

In such a laser beam printer, the outer cover
The outer surface of 2d functions as an end regulating surface that regulates the rear end of the sheet member discharged to the receiving portion 80, and the inner surface of this outer cover 2d defines a part of the transport path, and in this connection, the device The configuration can be simplified.

In order to prevent the sheet member discharged to the receiving portion 80 from blocking the hole 112 formed in the outer cover 2d, as shown in FIG. 1, a restriction ridge extending vertically on the outer surface of the outer cover 2d.
120 are provided at intervals in the width direction (for example, guide ridge 106
It is preferable that these restriction ridges 120 be provided at the site opposite to the above). With this configuration, the receiving portion 80
The sheet member discharged to the above is discharged in a laminated state as shown in FIG. 1 by contacting the rear end of the sheet member with the regulating projection 120, and thus a space is formed between the outer surface of the exterior cover 2d and the rear end of the sheet member. It remains and the hole 112 is not substantially blocked.

It is to be noted that one side of the exterior cover is made to function as an end regulating surface that regulates one end of the sheet member discharged to the receiving portion, and the multiface of the part is configured to define a part of the transport path. The idea can be applied to various devices such as a document transport device that transports stacked documents one by one through the scanning area.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing a specific example of a laser beam printer as an example of the apparatus of the present invention. FIG. 2 is a partially enlarged cross-sectional view showing the vicinity of the upstream end of the transport path in the laser beam printer of FIG. FIG. 3 is a partially enlarged perspective view showing a state in which a part of the outer cover of the laser beam printer of FIG. 1 is opened. 2 …… Housing 2a, 2b, 2c, 2d, 2e and 2f ……… Exterior cover 6 …… Process unit 42 …… Transport mechanism 56 …… Manual supply means 58 …… Automatic supply means 80 …… Reception part 82 …… First detection mechanism 90 ... Second detection mechanism 92 ... Optical detection means 94 ... Detected member 96 ... Operating portion 98 ... Detected portion 106 and 108 ... Guide ridges 112 and 114. Cooling hole 120 ... Regulation ridge

Claims (3)

[Claims] 1. A sheet member supplied from a supply means is conveyed through a conveying path, an image is formed on the surface of the sheet member while being conveyed through the conveying path, and a detecting mechanism for detecting the sheet member is provided in the conveying path. In the image generating apparatus provided, the detection mechanism includes a detected member that is moved by the action of the sheet member and a detection unit that detects the detected member, and the detected unit places the sheet member on the downstream side. An image forming apparatus characterized in that it also functions as a guiding means for guiding. 2. The detected member has a working portion acting on the sheet member, a detected portion detected by the detecting means, and a first position not detected by the detecting means and a first position detected by the detecting means. It is movable between two positions, the acting portion guides the sheet member conveyed through the conveying path to the downstream side, and the member to be detected moves from the first position by the action of the sheet member thus conveyed. The image generating apparatus according to claim 1, wherein the image generating apparatus is moved to the second position. 3. The member to be detected is rotatably mounted on a rotary shaft on which a feeding roller is mounted for feeding a sheet member,
The action portion guides the sheet member supplied by the rotation of the feeding roller to the conveying roller, and the detected member moves from the first position to the second position by the action of the sheet member thus conveyed. The image generating device according to claim 1 or 2, wherein the image generating device is a display device.