JPH0690551B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus such as a copying machine,
Among them, the present invention particularly relates to an image forming apparatus in which an original is scanned by a movable mirror and a main body of the apparatus can be divided.

[Prior Art and Problems] For example, in a copying machine, the transfer paper stays in the transport path due to some factors and becomes a paper jam. Various methods have been considered to deal with the occurrence of so-called jam. An example is a so-called alligator type copier, which divides the main body of the apparatus into a plurality of parts.

The alligator type copier is a device devised for facilitating the jam processing, so that when a paper jam or the like occurs inside the machine, it can be opened along the conveyance path with one-touch.

FIG. 1 shows an example of this alligator type copying machine.

The original document OR on the original document table 9 of the copying machine 8 is illuminated by the illumination lamp 10, scanned by the optical system including the scanning mirrors 11, 12, 13 and the lens system 14 and projected onto the photosensitive drum 18.
Around the photosensitive drum 18, a charging unit 19, which is a known image forming unit, a developing unit 20, transfer / separation units 21 and 22, and a cleaning unit 23 are arranged. The transfer paper P, which is the final image carrier, is selectively delivered from the paper storage trays 24a, 24b by rotating either of the paper feed rollers 25a, 25b. Further, the roller pair 26 conveys the toner image on the photoconductor 18 in synchronism with the toner image.
8. The paper is stored on the paper output tray 30 by the paper output rollers 29 with the copy image formed.

In FIG. 1, reference numeral 31 denotes a document pressing plate 15, 16, 17 which is a mirror forming a part of the optical system. Further, in the copying machine 8, the upper main body 35 including the optical system including the scanning mirrors 11, 12, and 13, the lens system 14, the mirrors 15, 16, and 17 and the document placing table 9 is moved to the lower main body 36 around the rotation fulcrum 37. It has a rotatable mechanism.

The scanning optical system will be described. The original OR placed on the original placing table 9 is illuminated by the illumination lamp 10 and moves in parallel with the original placing table 9 in the direction of the arrow T to be integrated therewith.
Scanning is performed by the mirror 11, the second mirror 12 and the third mirror 13 that move in the same direction at a speed half that of the first mirror 11.

Thus, the light flux from the original which is sequentially reflected by each mirror is incident on the lens system 14, and after being emitted, is reflected on the mirrors 15, 16 and 17 in order and is incident on the photosensitive drum 18.

Regarding the magnification conversion, the lens system 14 is moved in the same direction as the scanning direction of the third mirror 13 to change the optical path length between the original and the lens, thereby performing the conversion of reduction and enlargement.

Furthermore, regarding the scanning mirrors 11, 12, and 13, even when the lens system 14 is moved, the stroke of the mirror base is converted according to each magnification as shown in FIG. Do not collide.

However, in the event of a problem such as a jam, or because it is not controlled when the power is off, the scanning mirrors 11, 12, and 13 can slide freely even if the lens system 14 is within the movable range of the scanning mirror. Therefore, for example, when the upper main body 35 is opened for a jam treatment, a situation occurs in which the upper body 35 slides under its own weight and collides with the lens system 14 in the middle.

Here, since the lens is an ultra-precision component and is a very delicate object in terms of function, there is a possibility of losing the original machine due to a collision.

In order to prevent this from happening, a mechanism has been conventionally taken such that a stopper is applied when the scanning mirror is opened, or measures are taken to prevent the sliding of the scanning mirror and prevent it from slipping down by its own weight.

There are many known methods for providing a stopper, but the drawback is that several parts are used, leading to cost up, and a space for mounting the parts is required, which makes the device large. Things can be given.

As for the method of making the sliding of the scanning mirror worse, even if a motor that overcomes the resistance of sliding is attached, power consumption will increase by itself, and high quality images cannot be obtained in the state of poor sliding. .

[Structure for Solving Problems] The present invention has been made in view of the above problems, and discloses a method of preventing a collision between a scanning mirror and a lens system while suppressing an increase in the number of parts and power consumption. To do. The present invention has the following configurations.

That is, a scanning mirror that moves and scans a document placed on a document table, and a variable magnification lens that is arranged in the same optical path as the light reflected by the scanning mirror and is movable in the same direction as the scanning direction of the scanning mirror. , Driving means for moving the zoom lens,
An upper frame member that supports the scanning mirror and the zoom lens, and a lower frame member that supports the upper frame member so as to be openable and closable around a pivot shaft are formed on the recording material according to the original. In the image forming apparatus, a conveyance abnormality detection unit that detects a conveyance abnormality of the recording material, a lens position detection unit that detects the position of the zoom lens,
A control means for controlling the drive of the drive means, wherein the control means detects the conveyance abnormality of the recording material and the lens position detection means changes the displacement within the moving range of the scanning mirror. When it detects that there is a double lens,
The image forming apparatus is characterized in that the driving means is controlled so that the zoom lens moves out of the moving range of the scanning mirror.

[Embodiment] In the image forming apparatus of this embodiment, several photo sensors are provided in the transfer paper passage in the main body of the apparatus. For example, in FIG. 1, the sensor 40 disposed in front of the register roller 26 may have the following conditions as conditions for detecting a jam as shown in FIG. For example, as in B, the paper does not reach the sensor 40 within the time limit of the paper feed timer. After reaching the sensor 40 as shown in C, the paper cannot pass through the sensor unit within the registration timer limit.

Even if the enlargement is instructed as shown by D in FIG. 3, if the jam occurs in the middle of the process, the flow is stopped as it is.

Then, the lens system 14 remains at the magnified position, and if the scanning mirror slides within the moving range in this state, it will collide.

Therefore, in this embodiment, as shown in FIG. 4, the scanning mirror 11 is detected by the photosensors 38 and 39 in FIG. 2 which detect a jam and confirm the position of the lens system 14 after a series of operations is turned off.・ Confirm whether it is within the movement range of 12 ・ 13, and if it is within the movement range, send a signal to the lens driving motor and return the lens system 14 to the home position, that is, outside the movement range of the scanning mirror. Incorporated.

As shown in FIG. 2, if the position of the lens system 14 is at least at the home position HP, the scanning mirror, especially the third mirror.
No collision with 13. From this, by moving the lens system 14 no matter where the lens is located when a jam occurs, there is no risk of colliding with the scanning mirror.

However, when a member such as the lens hood 1 is provided between the scanning mirror and the lens, it collides with the scanning mirror, but as shown in FIG. 5 and FIG. Is a member 2 and does not directly collide with the third mirror 13. Further, since the third mirror 13 is held via an elastic body such as a leaf spring and the member 4 and the lens hood 1 contact each other in a wide range, the function of the third mirror 13 is impaired. There is no shock.

[Advantages of the Invention] With the configuration of the present invention, when a transfer sheet is jammed, the lens system is retracted out of the moving range of the scanning mirror to open the crocodile-type main body and the like. Even if the sliding occurs, the collision between the lens system and the scanning mirror can be avoided.

[Brief description of drawings]

FIG. 1 is a sectional view of a copying machine to which the present invention can be applied, FIG. 2 is a view showing a positional relationship between a lens system and a scanning mirror, FIG. 3 is a flow chart showing a jam detection sequence, and FIG. 4 is a book. FIG. 5 is a flow chart showing the sequence of movement of the lens system according to the invention, FIG. 5 is a plan view of the lens system and the scanning mirror portion,
FIG. 6 is a side view of the portion of FIG. 1 …… Lens hood 10 …… Illumination lamp 11 …… First mirror 12 …… Second mirror 13 …… Third mirror 14 …… Lens system 35 …… Upper body 36 …… Lower body 37 …… Rotation fulcrum

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-164735 (JP, A) JP-A-60-114849 (JP, A) Actual opening 59-173060 (JP, U) Actual opening 61- 99156 (JP, U) Actually opened 61-137957 (JP, U) Actually opened 62-65657 (JP, U)

Claims (1)

[Claims] 1. A scanning mirror for moving and scanning an original placed on an original table, and a variable magnification which is arranged in the same optical path as the light reflected by the scanning mirror and is movable in the same direction as the scanning direction of the scanning mirror. Lens, driving means for moving the zoom lens, an upper frame member for supporting the scanning mirror and the zoom lens,
An image forming apparatus for forming an image according to a document on a recording material, the lower frame supporting the upper frame so as to be openable and closable about a rotation support shaft An abnormality detecting means, and a lens position detecting means for detecting the position of the zoom lens,
Control means for controlling the drive of the drive means, wherein the control means detects the conveyance abnormality of the recording material and the lens position detection means changes the movement within the moving range of the scanning mirror. When it detects that there is a double lens,
An image forming apparatus, characterized in that the driving means is controlled so that the zoom lens moves out of a moving range of the scanning mirror.