JPS60138526A - Light shielding device of copying machine - Google Patents

Abstract

PURPOSE:To eliminate the trouble of replacing operation of an endless beltlike photosensitive body by providing a support frame which supports a light shield member in a rocking state, and supporting the support frame pivotally on a main body so that the frame is turnable up to a position distant from the endless beltlike photosensitive body. CONSTITUTION:When a solenoid 9 is excited to attract a spindle 12, an arm member 14 is driven through a crank and a link 13 and the arm member 14 turns around a pivot shaft 3 shown by an arrow B. Simultaneously, an occluder 1 also turns and is raised upward to expose a shielded area part 51. Further, the light shield device 4 turns upward by 180 deg. around the axial line of the pivot shaft 16 to the position symmetrical on the pivot shaft 16. The light shield device 4 leaves the installation range of the endless beltlike photosensitive body 2 at this point, and never causes impedance to the replacing operation of the photosensitive body 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applied to a full-exposure type electrophotographic copying machine, in which the N-light surface of an endless belt-shaped photoreceptor is partially shielded depending on the original size. This relates to the shielding device.

In a conventional full exposure type copying machine, a flash lamp illuminates the entire surface of the original placed on the platen by a flash lamp of 100 μJ? ec
By illuminating for a relatively short period of time, an endless belt-shaped photoreceptor is exposed to light through an optical system, and an electrostatic latent image of the original is formed on the photoreceptor. During exposure, the original and the photoreceptor are both stationary, or if the photoreceptor is moving, the exposure is done in such a short time that it can be considered that the relative relationship between the original and the original does not change. However, in any case, the endless belt-like photoreceptor moves to expose one original image, and when the unexposed photoreceptor surface comes to the exposure position, the next original image is exposed. be exposed.

It may be shorter than that for a large-sized original, and this is also desirable from the standpoint of increasing work efficiency. However, in this case, when copying a small original, there is a situation where the next exposure is performed on the area that was exposed in the image of the previous original and has not yet moved out of the exposure range of the large original. occurs.

For this reason, a light shielding member, that is, a light shielding member, has been conventionally provided to partially shield the exposure range on the photoreceptor depending on the size of the document to regulate the exposure area.

FIG. 1 is a schematic diagram of a conventional full-surface exposure type copying machine equipped with such an off-ruder, and 01 is an off-ruder.

L1-4.3I- indicate the position of the original latent image formed on the endless belt-like photoreceptor, respectively.

L, .about.4 indicate the latent image positions when copying a large original, such as an A3 size original, and S, .about., show the latent image positions when copying a small original, such as an A4 size original. In other words, in the copying machine shown in FIG. 1, at a constant copying magnification, if the original size is A, the moving distance of the photoreceptor from exposure to exposure, in other words, the pitch of the image on the photoreceptor is P, So, when the document size is A4, the image pitch is P2.
Therefore, Pr>pt.

Exposure is done at fixed positions -1 and S,
The right end A of , is made to match regardless of the size of the document. 02 is the lens position when photographing the original mV folds of AQ size, and the exposure range at this time is AB, which coincides with TS. When copying an A4 size original 1 tawM with this copying machine, it is moved to lenses 02 and 03, and corner registration is performed so that the right end of the original image occupies position 111A and the left end occupies position O on the photoreceptor. The exposure range at this time is AE' (the area to the right from A is always shielded from light), and if the image pitch P9 is small, the right end of the latent image S2 formed by the previous exposure as shown in the figure. Part B
/ D remains in the exposure range A B' and will be exposed again, so in order to block at least this part i,
Conventionally, a ruler O1 was not provided.

The conventional offruder 〇'l is the tth! As shown in IJ, it consists of a plate-shaped member that is pivotally supported on the copying machine main body via the upper end Z pivot shaft 04, and is swingably suspended from the pivot shaft 04. As shown, it was designed to sway and cover five parts of the MS.

However, such a conventional f/ruder has a narrow light-shielding area compared to its length, and in order to provide sufficient light-shielding, it requires a fairly large member, which becomes a nuisance when replacing the endless belt-shaped photoreceptor. It's difficult to work.

An object of the present invention is to overcome the above-mentioned drawbacks and to provide a light shielding device Z for a photocopier that does not obstruct one operation when replacing an endless belt-like photoreceptor.

Structure of the Invention In order to achieve the above-mentioned object, the light shielding device of the present invention is provided with a support frame that swingably supports the light shielding part for regulating the exposure n2 of the endless belt-like photoreceptor, and External iL from belt-shaped photoreceptor 7. - It is pivoted to the main body so that it can be rotated to the position.

According to the present invention, when replacing the endless belt-like photoreceptor, the entire light-shielding device is retracted to the outside of the installation location of the endless belt-like photoreceptor by rotating the support frame by, for example, 1000 degrees around the rotation axis. Because it is possible to
Replacement work can be easily carried out without being obstructed by the shading device.

In addition, the support frame can also be used as a stay for attaching other members such as an eraser lamp.

EXAMPLE Hereinafter, an example of the present invention will be explained with reference to FIGS. 2 to 4. Reference numeral 2 denotes an endless belt-shaped photoreceptor, and 4 a light shielding device provided close to the upper surface of the photoreceptor 2. These devices are housed in the main body of the copying machine along with other devices.

Also, the temperature of the upper surface of the endless belt-shaped photoreceptor 2 in FIG.
An area 5 surrounded by a chain line is exposed by a source containing an optical image of the document sent through the optical system. The endless belt-shaped photoreceptor 2 is driven in the direction of arrow a by a roll 6, and exposure is performed one after another in the exposure area 5. In the path of the endless belt-like photoreceptor 2, a C% developer, a transfer device, a cleaner, and a charger are sequentially provided adjacent to the photoreceptor 2.
The electrostatic latent image formed on the photoreceptor 2 as a result of the exposure area 5 to Celsius is developed with toner and transferred onto paper. .

The uniformly charged g n K state is circulated again to the exposure area 5 and exposed at next temperature.

(2) is an offruder, which is provided at the front end of both sides and can be rotated in the direction of the pivot shaft 3, and when it is in the position shown in FIG. and the rest 5. Only the exposed parts should be exposed. This off-ruder 1 is pivotally attached to a support frame 7 via the pivot shaft 3. As shown in the figure, the support frame 7 has a front portion 71 which is relatively high and a rear portion 72 which is relatively low, and the pivot shaft 3 is supported on this low rear portion 72 via a grout 8.
The pivot point 11+3 is placed as close as possible to the surface of the endless belt-like photoreceptor 20.

Said front portion 7 of the support frame 7. A solenoid 9 is fixed on the top, and a crank 10 is mounted on a pivot shaft 11 so as to be swingable in the horizontal direction.

The crank 10 has two arm pieces 10 that are approximately perpendicular to each other.
s, 102Y provided, - Nubindle 12 of the solenoid 9 is inserted into the long hole provided at the end of the arm piece 101.
The tips of the two are engaged. A long hole is also provided at the tip of the other arm piece 102, and the end W of the link 13 is engaged with this long hole. The other end of the link 13 is engaged with an elongated hole provided at the tip of an arm member 14 that is fixed to the τ Kruder IK and rotates around the pivot shaft 3. Therefore, energize solenoid 9 and spindle 1.
When the engine is moved 14, the arm member 14 is driven through the crank 10 and the link 13, and the arm member 14 rotates in the direction of arrow 6 about the pivot shaft 3, and the off-ruder 1 also rotates at the same time. Rising upwards and shielding until now ℃
The exposed area 51 can be exposed. The state of the off-ruder 1 and the like when it is in the open position in this manner is shown in solid lines in FIG. FIG. 3 also shows in phantom lines when the offruder 1 is in the shading device as shown in FIG. That is, the offruder l is supported on a pivot shaft so that it can swing between the light-blocking position shown by the chain line and the open position shown by the solid line. The exposure area on the principal 2 is controlled.

When the solenoid 9 is deenergized when the off-ruder 1 is at the solid line position in FIG. 3, the off-ruder 1 rotates around the pivot shaft 3 due to its own weight and moves to the ℃ chain line position, that is, the light shielding position. When the 1000-meter screw 1 is opened to a position beyond the vertical line passing through the pivot shaft 3, the spring that collides with the 1000-meter screw 1 near the open position will move the off-ruder 1 to the light-shielding position due to its own weight. Push it with the spring until it can be rotated to ℃・
.

Said front portion 7 of the support frame 7. n at the front end of both sides of
An arm member 15 is integrally provided and protruded, and this arm member 15 is rotatably supported by a bracket 17 via a pivot 16"i. The bracket 17 is fixed to the main body of the copying machine, In this way, the entire °C light shielding device 4 is rotatably supported on the copying machine body by the pivot shaft 16.The °C light shielding device 4 is supported by the pivot shaft 16 as shown by arrow C in FIG. The light shielding device 4 can be rotated 180° upwardly about the axis of the image, and can occupy a symmetrical position with respect to the axis as shown by the chain line in the same figure.The light shielding device 4 is an endless belt-like photosensitive device in the position shown by the chain line in Figure 4. 18 (Fig. 2) is a handle provided on the pivot s16 that separates the photoreceptor 2 from the installation range to the outside and does not interfere with the work when replacing the photoreceptor 2.18 (Fig. 2) When replacing the body 2, turn this handle 18 to move the light shielding device 14 to the dotted line position in Figure 4.If such a handle is installed, the support frame 7 should be turned directly by the hand. Alternatively, the pivot shaft 16"l may be driven by a motor via a suitable transmission mechanism.

In this embodiment, the axis of the pivot 116 is perpendicular to the traveling direction of the endless belt-like photoreceptor 2, but the light shielding device 4 has a pivot axis arranged parallel to the traveling direction on the negative side thereof. It may be rotated around the <, ': frs may be rotated horizontally around a vertical pivot shaft provided at one corner. The rotation angle of the light shielding device 4 is not limited to 180 degrees, and it is sufficient that the light shielding device 4 is detached from the installation range of the endless belt-shaped photoreceptor 2 to the outside. Portion 7I can be used to attach solenoid 9 and crank 10, as well as VC2 eraser lamp, etc.

Effects of the Invention As described above, in the present invention, the two support frames that support the light shielding member in a rotatable manner are rotatable from the endless belt-shaped photoreceptor at the outer position "f". Since it is pivoted to the main body, when replacing the endless belt-like photoreceptor, the entire light-shielding device can be removed outside the installation range of the endless belt-like photoreceptor, and the replacement work is not hindered by the light-shielding device. It depends on how easy it is to do.

The support frame can also be used as a stay for holding other parts such as an eraser lamp.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing a full exposure type copying machine equipped with a conventional light shielding device 7, Figs. 2 and 3 are perspective views showing an embodiment of the present invention, and Fig. 4 is an operational diagram of the same embodiment. FIG. ■... Ten thousand krug (light shielding member), 2... Endless belt-shaped photoreceptor, 3... Pivot shaft, 4... Light shielding device,
5... Exposure area, 6... Roll, 7... Support frame,
8...Bracket, 9°°° solenoid, 10・°°
Crank, 11... Pivot shaft, 12... Nubindle, 13... Link, 14... Arm member, 15...
Arm member, 16... Pivot shaft, 17... Bracket, 18... Handle. Agent: Patent attorney Nozomu Ehara and 2 others

Claims (1)

[Claims] In a full-exposure type electrophotographic copying machine that forms an image on an endless belt-like sensitive material through a Z optical system and performs hard copying, the exposure of the 1M endless belt-like sensitive material is controlled. A light-shielding device for a copying machine, characterized in that a support frame 2 for swingably supporting a light-shielding member is provided, and the support frame is pivoted to a main body so as to be rotatable to a position away from the endless belt-like sensitive element. ..