JPS60102662A - Image forming device - Google Patents

Abstract

PURPOSE:To clean a lens array by an extremely simple operation, by providing a means for shunting a reflecting plate from between an original platen and an image forming optical system by interlocking with a moving operation of the original platen. CONSTITUTION:When an original platen 2 is moved in the direction A, a frame of a final end of the original platen is folded and becomes a projection 2a. In the end of the direction A of an upper plate 9 of a device, a guide long hole 9b is opened on both side parts, and a damper 35 is fitted so as to be slidable. As for the damper 35, a spring 37 is extended to a device body chassis and drawn in the direction as indicated with an arrow C. When cleaning a short focus lens array 3, when the original platen 2 is pushed manually in the direction A from the final end state, a damper inclined surface part 35b hits against a lever 12 and turns counterclockwise. A supporting body 11 and a blank exposure reflecting plate 10 turn clockwise, are shunted from the upper part of the short focus lens array 3, and cleaning can be executed easily by inserting a cleaning member from an opening 9a of the upper plate of the device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the periphery of an image exposure optical system in an image forming apparatus such as a multiplex copying machine, and particularly in an image forming apparatus having a movable document table.

Conventionally, in electronic copying machines, when an image to be copied is smaller than an image carrier such as a photosensitive drum, a so-called blank mist is applied to the non-image area of the photosensitive drum. This blank exposure is performed to prevent unnecessary development toner from being consumed or a black border from being formed around the copy paper if the non-image area of the photosensitive drum is charged. For this reason, there is an apparatus in which a dedicated light source for blank exposure is provided and the light is irradiated onto the non-image area of the photosensitive drum to short-circuit and eliminate the charged charges. Recently, there are also devices that irradiate documents by reflecting the light from a light source on a document using a reflector or the like.

FIG. 1 shows a schematic diagram of an embodiment of an electronic copying machine having the latter blank exposure device. This electronic copy machine is
This is a type with a movable document table.

In the figure, l is a photosensitive tram which is an image carrier, and arrow R
It forms images while rotating in different directions. ? is a document table made of a transparent material such as glass, and moves in the direction of arrow A or B. 3 is the imaging optical system, which consists of a lens array with short focal length lenses such as SELFOC lenses;
The image of the upper document 0 is formed on the photosensitive drum l. 5 is a holder for the lens array A3. A lamp 6 illuminates the original image on the original platen 2, and also serves as a light source for blank exposure. Reference numerals 7 and 8 denote reflectors for the illumination lamps 6, and 9 denotes an upper plate of the apparatus, which has openings through which the illumination light from the illumination lamps 6 and the image light from the original are transmitted. Reference numeral 10 denotes a blank exposure reflecting plate, and 11 a support body rotatably supporting the reflecting plate IO, which is pivotally supported on the main body chassis by a rotating shaft 11a. 1
Reference numeral 2 denotes a rotating lever, which is supported by a rotating shaft 12a, and its tip engages with the folded recess 10a of the reflector lO. 13 is a solenoid, its plunger is lever 1
It is connected to the rear end of 2. 15 is a spring, lever 12
is biased to rotate clockwise. Reference numeral 16 indicates a stop collar, in which the lever 12 resists the bias of the spring 15 and closes the solenoid 1.
Regulates rotation by being pulled by 3. 17 is also a stopper, which restricts the rotation of the shield 8-12 by being pulled by the biasing force of the spring 15. Reference numeral 18 denotes a spring that is suspended between the support body 11 and the main body chassis.

In addition, 21 is a primary charger, 22 is a developing device, 23 is a paper feed roller, 25 is a register roller, 26 is a separation charger, and 27
is a separation belt, 28 is a transfer paper guide, 30 is a fixing device, 3
1 is a paper ejection roller, 32 is a paper ejection tray, 33 is a cleaner,
P is transfer paper.

FIG. 1 shows the state when the document table 2 makes one scanning movement. Solenoid 13 is energized.
12.Support 11.Blank front light reflection plate IO are in the positions shown. That is, the blank exposure reflecting plate 1O is retracted from between the document table 2 and the short focus lens array 3. Therefore, the light from the original illumination lamp 6 does not hit the blank exposure reflector 10 but hits the original O on the original platen 2, and the reflected light is imaged on the photosensitive tram 1 by the short focus lens array 3. Since the document 0 is moving in the direction of arrow A and the photosensitive drum 1 is rotating in the direction of arrow R, the document image is scanned and exposed.

When the document table 2 finishes moving to the end of the movement (scanning exposure is completed), the power to the solenoid 13 is cut off, and the platen 12 is pulled by the spring 15 and rotates to the stopper 17 position, and accordingly Blank exposure reflector plate l along with support 1'l
O is also rotated by the spring 18 and stops at the position shown in the second figure. That is, the blank exposure reflecting plate 10 extends between the document table 2 and the short focus lens array 3. Then, manuscript table 2
moves back in direction B. At this time, the document illumination lamp 6
The light hits the blank exposure reflecting plate 10 and is reflected, and the reflected light is irradiated onto the rotating photosensitive drum l via the lens array 3. As a result, blank exposure is performed on the photosensitive drum 1 following the scanning exposure of the original image.

Note that the process of forming an image on the photosensitive drum and copying it is well known, so a description thereof will be omitted.

In such a conventional apparatus, the blank exposure reflector 10 extends between the document table 2 and the short focus lens array 3 and always covers the lens array 3 except when scanning exposure is being performed. There is.

By the way, short focus lenses such as SELFOC, which are each unit of a short focus lens array, have a very small diameter. Therefore, even if a small amount of dust lands on the surface, a large portion of the light-transmitting part of the single-wooden lens will be covered, and the balance of light transmission for each lens will be disrupted.

The contrast of the formed image may partially decrease or the brightness may become uneven. To prevent this, it is necessary to frequently clean the surface of the short focus lens array 3. However, since the reflective plate 10 covers the upper part of the lens array 3, there is a drawback that cleaning is difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that eliminates these drawbacks of conventional apparatuses and allows cleaning of a lens array with extremely simple operations.

To achieve this object, the present invention scans and exposes the image of the original onto the surface of an image carrier, so when the original table moves, it is retracted from between the original table and the imaging optical system, and the image is When the exposure light path is opened and the return movement of the 110th movement is made, the document illumination light is passed between the document table and the imaging optical system, and the image exposure light path is closed. In an image forming apparatus equipped with a reflector that reflects light toward an image area, the reflector is moved toward the document table in conjunction with the operation of further moving the document table from the end of the document table's movement. The image forming apparatus is characterized by having means for retracting the image forming apparatus from between the image forming optical system and the image forming optical system.

Examples of the present invention will be described in detail below.

FIG. 3 shows a main part of an embodiment of an image forming apparatus to which the present invention is applied, and shows a state where the blank exposure reflector 10 has advanced between the document table 2 and the short focus lens array 3 after scanning exposure is completed. (corresponds to FIG. 2 of the conventional example). Components having the same configuration as the apparatus shown in FIGS. 1-2 are designated by the same reference numerals, and therefore, repeated explanation will be omitted. Original table 2 is A
The frame at the end of the document table when moved in the direction is folded in to form a protrusion 2a. At the inlet end of the L plate 9 of the device,
Guide elongated holes 9b are formed on both sides, into which dampers 35 are slidably fitted. A portion 35a of the damper 35 that protrudes from the second plate faces the document table protrusion 2a. The damper 35 has an abutment slope portion 35b, which rotates and
12" facing two slopes. Moreover, the damper 35 is
A spring 37 is connected to the main body of the device and is pulled in the direction of arrow C.

When cleaning the short focal length lens array 3 in such an apparatus, the document table 2 is manually pushed further in the direction A from the end position 8 (the state shown in FIG. 3). Then, the damper 35 is moved against the biasing force of the spring 37 by the original table protrusion 2a.
is pushed and moves along the guide elongated hole 9b. The damper slope portion 35b hits the lever 12 and rotates it counterclockwise.

The state at that time is shown in the perspective view of FIG. 4 (the document table 2 is not shown). Then, the support 11 and the blank exposure reflector 10 rotate in the direction of the clock 1, and the short focus lens array 3
Evacuate from above. In this state, the lens array 3 can be easily cleaned by inserting a cleaning member through the opening 9& of the upper plate of the apparatus. Note that the short focus lens array 3, holder 5, blank exposure reflector 10, support 11, solenoid 13, and other structures and operations are the same as those shown in FIGS. It is omitted in Figure 4.

The present invention can be implemented not by mechanical interlocking as in the above example but also by electrical interlocking that turns on and off the energization of the solenoid 13 that drives the lever 12. That is, a microswitch (not shown) is provided at a position where the protrusion 2a operates when the document table 2 is further moved from the scanning end. When the micro switch is turned on, the lever 12 is rotated counterclockwise, and the exposure reflector 10 is moved toward the lens array 3.
evacuate from above and become ready for cleaning.

Further, the position where the exposure reflection plate 10 is retracted for cleaning may be the start end of the exposure scan. That is, the structure includes a damper and a microswitch that operate when the document table 2 is further moved in the B direction from the end where the document table 2 has returned in the B direction.

As explained above, according to the device of the present invention, since there are no obstacles above the lens array, even a general user can clean the lens array very easily without the need for specialized service personnel. become.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a conventional electronic copying machine, Fig. 2 is an explanatory diagram of its main parts, Fig. 3 is a schematic diagram of main parts of an electronic copying machine to which the present invention is applied, and Fig. 4 is an explanation of its operation. FIG. 2 is a photosensitive drum, 2 is an original table, 3 is an imaging optical system consisting of a short focus lens array, 6 is an original exposure light source, 9 is an upper plate of the apparatus, 9a is an exposure aperture thereof, 9b is a guide slot, and 1O is a blank. Exposure reflector plate, 11 is its rotation support, 12 is a rotation lever, 13 is a solenoid, 15018/37 is a spring, 3
5 is a damper. Patent applicant Canon Co., Ltd.

Claims (1)

[Claims] (1) When the document table is moved in order to scan and expose the document image onto the image carrier surface, it is evacuated from between the document table and the imaging optical system to open the image exposure optical path, and return to the movement described in 111. When moving, a reflector is inserted between the document table 011 and the imaging optical system and reflects the document illumination light toward the non-image portion of the image carrier while closing the image exposure optical path. In the image forming apparatus, the reflector is retracted from between the document table and the imaging optical system in conjunction with the movement of the document table further from the end of the document table's movement. An image forming apparatus comprising: