JPS6356984B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laser recording device, and more specifically, the present invention relates to a laser recording device that controls a laser beam according to an image signal, scans the controlled laser beam, and records information on a photosensitive recording medium. The present invention relates to a laser recording device.

2. Description of the Related Art In recent years, so-called laser recording devices that record on a photosensitive recording medium such as a photoconductive layer using a laser beam have come into practical use.

By the way, in a normal copying machine that directly forms an image of an original onto a photoreceptor through a lens, the device is divided into a first housing and a second housing, and the second housing is rotated relative to the first housing. There is a known device that can be moved to open and close, thereby facilitating maintenance and inspection of process means, jamming of transfer materials, and the like.

In the present invention, the laser recording device is made into a separate main body type as described above, and is intended to facilitate maintenance and inspection of the process means and removal of transfer material jams. If the second casing containing the second casing is rotated and released from the first casing while it is rotating at high speed, abnormal force will be applied to the bearing of the rotation scanning means and this bearing may be damaged. be. The present invention solves this disadvantage.

Hereinafter, details of the present invention will be explained using specific examples with reference to the drawings.

FIG. 1 is a perspective view of a specific example laser recording device based on the present invention, and FIG. 2 is a sectional view thereof.

The laser recording device 1 is configured such that its housing is divided into a lower side and an upper side, and the lower first housing _H1 is left stationary, while the upper second housing _H2 is mounted on a hinge h.
The inside of the device is opened for maintenance and inspection by lifting its free end.

In this apparatus, a drum 2 supporting a photoreceptor is rotatably supported in order to form a recorded image by being scanned by a laser beam. In the illustrated example, a photoreceptor whose basic structure includes a conductive layer, a photoconductive layer, and an insulating layer is used. The photosensitive drum 2 is rotated in the direction of the arrow by a driving means (not shown).

Shuji's latent image forming position E on this photoreceptor drum 2,
Each process means is arranged at a development position D, a transfer position T, and a cleaning position C.

That is, at the latent image forming position E, there are a pre-static discharge corona discharger 3, a pre-exposure lamp 4, a primary corona discharger 5,
A secondary corona discharger 6, a full-surface exposure lamp 7, etc., which perform a corona discharge having a polarity component opposite to that of the primary corona discharge substantially simultaneously with laser beam scanning, are arranged.

At the development position D, a sleeve developing device 8 that supplies, for example, a one-component magnetic developer is arranged.

Further, a magnet roller cleaner 9 is arranged at the cleaning position C to remove developer remaining on the surface of the photoreceptor after transfer.

Further, in order to supply the transfer material 10 to the transfer position T, there is provided a supply cassette 11 which is removably attached to the apparatus, a feed roller 12 which feeds out the transfer material from the supply cassette, guide plates 13 and 14 which guide the transferred transfer material.
17, 18, and timing rollers 15, 16 for feeding the transfer material so as to match the image position on the photosensitive drum 2. Then, a transfer corona is applied from the back side of the transfer material supplied to the transfer position by a transfer corona discharger 19 to perform transfer. The transfer material is then peeled off from the surface of the photosensitive drum 2 by the separation roller 20 and transferred onto the conveyor belt 21.
The transfer material conveyed by the conveyor belt 21 passes through the fixing device 22 and completes the transfer of the unfixed transfer image.

23 is a discharge roller, and 24 is a paper discharge tray.
On the other hand, the mechanism that scans and exposes the photoreceptor drum 2 is
Light sources L, B, and G that emit laser beams according to image signals, a rotating polygon mirror 25 that scans the laser beams, an fθ lens system 26, and a reflecting mirror 27
etc.

In addition, near the rotating polygon mirror 25 , in order to detect the rotation state thereof, for example, a lamp RD ₁ and a photoelectric element RD ₂ are installed.
A rotation detecting means RD having a rotation detecting means RD is disposed to prevent damage to the rotating polygon mirror which rotates at high speed, as will be described in detail later.

FIG. 3 is an enlarged sectional view of a specific rotating polygon mirror.
A polygon mirror 251 is fixed to a rotating shaft 252, which is rotatably supported by bearings 253 and 254. Further, a rotor 255 is fixed to the rotating shaft to form a drive motor, and a coil 256 is arranged along the outer circumference of the rotor 255. Further, a brake disc 257 is fixed to the lower end of the rotating shaft, and the rotating polygon mirror is decelerated or stopped by the contact operation of the brake shoe 258.

FIG. 4 is a sectional view of the device with the second casing open.

As is clear from the figure, the photosensitive drum 2 and its scanning exposure mechanism are both attached to the second housing and move, so a constant optical relationship is always maintained between the two, and there is no risk of deviation in the optical distance. .

In addition, normally the developing means, the cleaning means, etc. are located on the transfer material feeding path, but since these means are also installed in the second casing, the transfer material path is changed by the pivoting of the second casing. will be released. Therefore, even if a jam occurs on the path, it can be easily removed, and the transfer means and fixing means on the path can be easily maintained.

Furthermore, as is well known, scanning exposure mechanisms such as laser light sources and rotating polygon mirrors rotate at high speed and require precision, so they must be robust and therefore heavy. However, as in this embodiment, since it is provided near the pivot shaft 28, the pivot of the second casing is not hindered. Moreover, as shown in the illustrated example, since the weight of the exposure mechanism acts on the pivot shaft 28 on the side opposite to the example of pushing up the second housing, the balance weight is applied when the second housing is opened. Use it as
The second casing can be opened and closed smoothly.

By the way, in the laser recording apparatus having the above configuration, the rotating polygon mirror rotates at high speed during the recording operation. Even if the power supply to the drive motor of the rotating polygon mirror is stopped after recording ends, the rotation will continue for a while due to inertia.

If the second housing is opened when the rotating polygon mirror is not sufficiently decelerated due to inertia, the rotation axis of the rotating polygon mirror will be tilted, and there is a risk that an abnormally large force will be applied to the bearings and the like. This is due to changes in angular momentum, but it causes wear on bearings, etc., which require precision due to high-speed rotation, and sometimes causes damage to the bearings, which is extremely inconvenient.

Therefore, in the device according to the present invention, a lock mechanism is provided that does not release the connection between the first housing and the second housing until the rotating polygon mirror is sufficiently decelerated.

That is, the device 1 is provided with a lock and release means 30 at the end opposite to the fulcrum 28 of the hinge, which is used to open and close the second casing.

FIG. 5 is a perspective view showing essential parts of the locking and unlocking means 30. Side plate 31 of the second housing,
A shaft 34 is rotatably supported between 32 via a bearing 33. A lock release handle 35 and a lock pawl 36 are fixed to the shaft 34. The axis 3
4 is always biased in the direction of arrow A by a torsion coil spring 37, and the lock pawl 36 is pressed against the side plate 38.
By engaging with a hole 39 provided in, the device 1 is kept in a closed state.

When opening the device in such a state, for example, for jamming, etc., hold the handle 35 and move the shaft 34 in the opposite direction of arrow A against the force of the torsion coil spring 37. By rotating, the engagement between the lock pawl 36 and the hole 39 is released, and after being opened by a lift-up means (not shown), it remains stationary. A lever 40 is fixed to one end of the shaft 34, and a solenoid 41 is disposed near the tip 40a of the lever 40. When the device 1 is in operation, the solenoid 41
The plunger 42 is located at a position intersecting the tip 40a of the lever. Therefore, in this state, it is impossible to release the lock using the handle 35. Furthermore, even if a problem such as a jam occurs and the operation of the device is stopped, the lock cannot be immediately released. That is, the input signal to the solenoid 41 is stopped after a predetermined period of time has passed after the power supply to the laser light source and the rotating polygon mirror drive source is stopped. As a result, the plunger 42 is displaced in the direction of arrow B, and the lever tip 4
Evacuate from the intersection with 0a. Only in this state can the lock be released by the handle 35. This delay time is set according to the inertia determined by the weight and shape of the rotating polygon mirror 25, the number of revolutions used, etc., and can be implemented using an appropriate delay circuit. This delay time may be set as the time until the rotating polygon mirror stops rotating, but it is effective to set the time until the abnormal force due to the tilt of the rotation axis drops to a level that does not cause any practical problems. It is.

Furthermore, in order to prevent the second casing from opening during the above-mentioned high-speed rotation, the rotation speed detection means RD of the above-mentioned rotating polygon mirror is installed.
It is also effective to use

That is, the solenoid is turned off only when the rotational speed detection means RD detects that the rotating polygon mirror has stopped or has decelerated to below a predetermined rotational speed. In this case, it is of course effective to control the rotation speed detection means RD alone, but it is also possible to use it together with the delay circuit described above and release the lock when both the conditions of delay time elapse and rotation speed detection are satisfied. This configuration further improves safety and is effective.

Further, in order to shorten the time required for natural attenuation of the inertial force of the rotating polygon mirror, it is effective to use the brake mechanism provided in the mechanism shown in the third figure.

That is, the brake is controlled so as to operate quickly at the same time as or immediately after stopping the driving of the rotating polygon mirror.

In this way, after the recording operation of the apparatus is stopped, the apparatus can be opened quickly and jams can be cleared quickly.

According to the present invention, the second casing of the device can be rotated and opened relative to the first casing of the device in order to facilitate maintenance and inspection inside the device, and the second casing can be rotated to open the second casing of the device. It has a built-in scanning means, but the second
The locking means for locking the housing in the closed state with respect to the first housing is prohibited from being unlocked during the recording operation of the apparatus, and after cutting off the supply of driving force to the rotational scanning means,
This prohibition is canceled after a predetermined period of time has elapsed, or the above-mentioned prohibition is canceled when it is detected that the rotation scanning means has stopped or has decelerated to a predetermined rotation speed or less.
It is now possible to prevent an accident in which the second casing is opened while the scanning means is rotating at high speed and the bearing is damaged.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a specific example laser recording device based on the present invention, FIG. 2 is a sectional view thereof, and FIG. 3 is a
An enlarged sectional view of a specific example rotating polygon mirror, FIG.
FIG. 5 is a cross-sectional view of the illustrated device with the second casing open, and FIG. In the figure, 1: laser recording device, 2: photosensitive drum, 3: pre-static discharge corona discharger, 4: pre-exposure lamp, 5: primary corona discharger, 25 : rotating polygon mirror.

Claims (1)

[Scope of Claims] 1. In a laser recording apparatus that scans and exposes a photoreceptor by scanning a laser beam controlled in accordance with an image signal with a rotary scanning means rotationally driven by a drive source, a first device that is left still; a casing, a second casing of the device that is rotatably supported to be openable and closable by rotating around a predetermined axis relative to the first casing of the device, and includes the rotational scanning means; A locking means for locking the first housing of the apparatus in a closed state; a locking means for prohibiting release of the locking by the locking means during recording operation of the apparatus; and after cutting off the supply of driving force to the rotational scanning means; A laser recording device comprising: a control means for canceling the prohibition after a predetermined period of time has elapsed. 2. A laser recording device that scans and exposes a photoreceptor by scanning a laser beam controlled in accordance with an image signal with a rotary scanning means rotationally driven by a drive source, comprising: a device first housing that is left stationary; a second device casing that is supported to be openable and closable by rotating around a predetermined axis relative to the first casing, and includes the rotational scanning means; and a control means for prohibiting release of the locking by the locking means during recording operation of the apparatus, and releasing this prohibition after cutting off the supply of driving force to the rotation scanning means. A laser recording device comprising: a control means that detects the rotational speed of the rotational scanning means and releases the inhibition when it is detected that the rotational scanning means has stopped or has decelerated to a predetermined rotational speed or less. .