JPH0690550B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus such as a copying machine and a printer, and in particular, an image forming apparatus whose main body can be divided into a first casing and a second casing. It is about.

[Conventional Technology and Problems] Conventionally, in this type of apparatus, a micro-device for detecting a light receiving element for detecting the amount of light, detecting copy paper, detecting the position of a document table, and the like.
A sensor such as a SW or a photo interrupter has a sensor arranged in the detection section and is wired to the control board of the main body by a lead wire or the like.

However, if the lead wire becomes long, electrical noise may be picked up and may be erroneously detected.

Also, not only the sensor alone, but the substrate supporting the sensor and the amplification circuit must be placed in the detection unit as a unit, which is a great spacer limitation.

Further, in the case of an image forming apparatus in which the alligator type main body can be divided into a first casing and a second casing, it is necessary to provide wiring between the first casing example and the second casing side. If it is pinched, the lead wire may be damaged.
Furthermore, the wiring was troublesome at the time of assembly. In order to avoid wiring between the first and second casings in this way, a connector or a relay board provided near the boundary surface of both casings is also used, but due to repeated opening and closing operations of both casings, The contact deteriorated, which was also the cause of poor contact.

[Configuration for Solving Problems] The image forming apparatus of the present invention is made in view of the above-mentioned problems, and includes a first housing and a second housing that can be opened relatively to the first housing. , A light source that is attached to the second casing and irradiates a document placed on a document table with light, a light receiving sensor disposed in the first casing, a holder that houses the light receiving sensor and is attached to the first casing, and one end Is attached near the light source, and the other end is attached to the second casing so as to be swingable, and the light emitted from the light source with the first casing and the second casing closed. An image forming apparatus that receives light from a light receiving sensor through a light transmitting unit and adjusts the light source based on the amount of light detected by the light receiving sensor, wherein the light is emitted when the first housing and the second housing are closed. Hold the holder so that the end portion of the transmission means and the light receiving sensor maintain a predetermined distance. The da has an abutment surface for receiving an end of the light transmitting means.

[Embodiment] FIG. 1 is a sectional view showing an embodiment of an electrophotographic copying machine according to the present invention. Further, FIG. 2 shows a state in which the second housing 21 constituting the apparatus main body 1 is opened in the embodiment shown in FIG. Around the image carrier drum 2 which is pivotally supported by the second housing 21 and rotates in the direction of the arrow, the corona discharge unit 3, the short focus optical element array 4, the developing device 5, the transfer corona discharge device are arranged along the rotation direction. 6 and cleaner 7 are arranged in this order. Then, after uniformly charging the surface of the image carrier drum 2 by the corona discharger 3, the document set on the reciprocating document table 10 is illuminated by the fluorescent lamp 11, and the reflected light thereof is a short focus optical element array. An image is formed on the surface of the image carrier drum 2 via 4. Then, this electrostatic latent image is developed as a toner image by the developing device 5.

On the other hand, the transfer papers P set on the paper feed tray 12 are separated and fed one by one by the paper feed roller 13, and are sent to the transfer unit by the registration roller pair 14 at the same timing.

The transfer paper P on which the toner image is transferred in this manner is fixed on the toner image by the fixing roller pair 17, and is ejected from the apparatus main body 1 via the paper ejection roller pair 18.

Reference numeral 19 is a first housing, and a second housing 21 is supported to be openable and closable around a shaft 20. FIG. 2 shows a cross section of the main body with the second housing opened. 22 is an optical fiber, one end
The optical fiber holding member 23 is provided with 22a located near the fluorescent lamp 11 at a distance a and the other end 22b located on the opposite side in the second housing.
It is fixed to. The holding member 23 is the first and second swing levers.
It is swingably held with respect to the second housing 21 via 24 and 25. The sensor 26 is for detecting the light amount of the fluorescent lamp 11 and adjusting the light intensity, and is fixed on the control board 28 on the first housing 19 via the holder 27.

Further, 29 is a paper detection photo interrupter, which is a control board.
It is fixed on 28. The detection lever 30 is rotatably supported by a pin 31 on the second housing. When one end 30a is pushed by the transfer paper P, the detection lever 30 rotates clockwise, and the other end 30b interrupts the optical path of the photo interrupter 29 and the timing of the paper. To detect. The photo interrupter 29 may use a micro SW.

FIG. 3 shows a plan view of the second housing 21 as viewed from above.

The position of the fiber end 22a of the fluorescent lamp 11 side in the paper width direction is
Since the amount of fluorescent light varies at the edges, it is preferable to install it near the center.Especially in a device that feeds transfer paper based on the center, it is necessary to always measure near the center even for small-sized transfer paper. Since it is sufficient, the image exposed portion can be directly measured, which is more preferable.

FIG. 4 shows a detailed view of the optical fiber end portion 22b and the sensor 26 portion. Further, FIG. 5 is a perspective view of the same portion.

The optical fiber holding member 23 is supported by the guide portion 24a of the first swing lever 24 so as to be vertically movable, and is biased downward by the leaf spring 32.

Further, the first swing lever 24 is a pin on the second swing lever 25.
It is rotatably fitted on 25a. Further, 24b is an elastic member integrally molded with the first swing lever 24, which holds the first swing lever 24 at the center position and always keeps the fiber end 22b at the center position when closing the second housing. keeping. Similarly, the second swing lever 25 is rotatably supported by the pin 33 of the second housing 21, and is held at the central position by the elastic member 25b.

The optical fiber holding member 23 is inserted into the holder 27 of the sensor 26 by guiding the optical fiber holding member 23 when the second housing 21 is closed, and the optical fiber holding member 23 is fitted to the optical fiber holding member 23. The end face of the fitting portion 27b for positioning with the optical fiber holding member 23 and the end face of the optical fiber holding member 23 are abutted by the urging force of the leaf spring 32, so that the abutting surface 27c for releasing the gear gap between the optical fiber 22 and the sensor 26 is formed. It is provided.

With the above configuration, the positional relationship between the sensor 26 and the outermost end surface 22c of the optical fiber 22 can always be maintained at a constant interval when the second housing 21 is closed as shown in FIG.

Further, the holder 27 of the sensor 26 may be provided with a shutter 34 as shown in FIG. 6 in order to prevent foreign matter from dropping from above and accumulation of dust. The shutter 34 is rotatably held around a pin 35 on the side surface of the holder 27 and is urged clockwise by an urging means (not shown). In the state where the second housing 21 is closed, the end portion 34a of the shutter is pushed down by the engaging portion of the second housing 21 (not shown), and the holder 34 and the optical fiber holding member 23 are rotated to the position shown by the solid line in FIG. Does not prevent the engagement of the. While the second housing 21 is opened, the shutter 34 is rotated clockwise by the urging means to move to the position shown by the alternate long and short dash line in FIG. 6 to cover the upper surface of the sensor and prevent foreign matter from falling or dust from accumulating. It can be prevented.

[Effects of the Invention] As described above, according to the configuration of the present invention, it is possible to perform good detection operation without picking up noise when transmitting the detection result from the second housing to the first housing.

Further, since there is no fear of noise, the transmission distance of the detection result can be extended, and the sensor can be concentrated on a specific location on the first housing side.

Further, since the light transmitting means (the optical fiber in this embodiment) is used, it is sufficient that the sensor portion has a space for accommodating the diameter of the optical fiber, and the degree of freedom of the sensor arrangement is increased.

In addition to the effects specified in the present embodiment, in the state where the first casing and the second casing are closed, the light transmission means forms a closed system with respect to the outside even at the connecting portion of both the casings, The stray light of can be blocked. In this embodiment, the optical fiber is used as an example of the light transmitting means, but the same effect can be obtained even if the light transmitting system including the mirror and the lens is used.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a copying machine using the present invention,
2 is a sectional view showing a state where the second housing is opened in the copying machine of FIG. 1, FIG. 3 is a schematic plan view showing an upper surface of the second housing, and FIG. 4 shows a connection state of the optical fiber and the sensor. 5 is a perspective view showing the relative relationship between the optical fiber and the sensor, and FIG. 6 is a sectional view showing the second embodiment of the connecting portion between the optical fiber and the sensor. 11 ... Fluorescent lamp, 19 ... First housing, 20 ... Shaft, 21 ... Second housing, 22 ... Optical fiber, 23 ... Holding member, 24 ... First swing lever, 25 ... … Second swing lever, 26 …… Sensor, 27 …… Holder.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Shinji Kanemitsu 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hajime Kitajima 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Within the corporation (56) Reference JP 57-99656 (JP, A) JP 58-103096 (JP, A) JP 60-230153 (JP, A) Actual development Sho 53-147738 (JP, A) U) Actually open 59-9339 (JP, U) Actually open 61-33048 (JP, U) Actually open 62-38653 (JP, U) Actually open 62-199747 (JP, U)

Claims (1)

[Claims] 1. A first casing, a second casing which can be opened relative to the first casing, a light source which is attached to the second casing and irradiates a document placed on a document table with light. A light receiving sensor arranged in one housing, a holder accommodating the light receiving sensor and attached to the first housing, and a light transmitting means having one end attached in the vicinity of the light source and the other end swingably attached to the second housing. The light emitted from the light source in a state where the first housing and the second housing are closed is received by the light receiving sensor through the light transmitting means, and the light source is adjusted based on the amount of light detected by the light receiving sensor. An image forming apparatus that emits light, wherein the holder is configured so as to maintain a predetermined distance between the end portion of the light transmitting means and the light receiving sensor when the first housing and the second housing are closed. Formation having an abutting surface for receiving the end of the sheet Location.