JPH0844161A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To prevent a laser beam from being leaked to the outside by surely intercepting the optical path of an optical system in the case of opening an upper case while making the device small in size and inexpensive. CONSTITUTION:This device is equipped with a shutter member 21 which can be positioned and held at either of an optical path intercepting position and an intercepting releasing position, an energizing spring 31 which energizes the shutter member 21 so that it may be positioned and held at the intercepting position, and a pressing rib 41 which positions and holds the shutter member 21 at the intercepting releasing position by exerting external force on the shutter member 21 by using closing force acting on the upper case 1U when the upper case 1U is closed, and which allows the shutter member 21 to restore to the intercepting position when the upper case 1U is opened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus such as a laser printer having an optical system.

[0002]

2. Description of the Related Art An electrophotographic apparatus irradiates a photosensitive member with laser light from an optical system based on print data to form an electrostatic latent image,
After the latent image is developed, it is generally configured to be transferred and fixed on a sheet.

A typical conventional example of such an electrophotographic apparatus is shown in FIG. In the figure, reference numeral 1 is a main body case in which each component of the electrophotographic apparatus is built. The main body case 1 is divided into two parts, a lower case 1L and an upper case 1U, so that the internal parts can be easily replaced, maintained, and inspected. The upper case 1U is a lower case via a fulcrum (rotational connecting portion 3). It is openably and closably connected to 1L.

Here, in the lower case 1L, an electrophotographic process unit 5 (photoconductor 6, charging device 7A, developing device 7B, photoconductor cleaning device 7C, etc.), transfer device 8 and fixing device (not shown), etc. are provided. It is provided.

On the other hand, the optical system 11 is often provided in the upper case 1U for the convenience of attaching and detaching the electrophotographic process unit 5. This optical system 11 has an upper case 1U.
It has a box-shaped optical case 17 mounted on the optical source 17, and the optical case 17 has a light source 12 and optical parts (lens 14,
Reflecting mirror 15 and polygon mirror 1 as a rotating polygon mirror
6) etc. are built in. In addition, the optical case 17 includes
An emission port 18 is provided so as to face the photoconductor 6.

The laser light emitted from the light source 12 based on the print data travels along the optical path L and travels along the polygon mirror 1.
Light enters at 6. Then, the laser light is polarized and scanned by the polygon mirror 16 that is rotationally driven in a predetermined direction, and then is imaged on the peripheral surface of the photoconductor 6 through the lens 14, the reflection mirror 15, and the like to form a minute beam spot. Form. In this way, an electrostatic latent image is formed by a large number of beam spots formed on the photoconductor 6. The electrostatic latent image formed on the photoconductor 6 is developed by the developing device 7B, and transferred and fixed by the transfer device 7C and the fixing device.

By the way, in the above-mentioned electrophotographic apparatus, when the upper case 1U is opened for internal inspection,
Since it is dangerous for the laser beam to directly hit the human body, various safety measures have been taken.

As one of the safety measures, the upper case 1
A drive stop device (not shown) that stops the drive of the light source 12 by detecting the opening of U by a micro switch or the like is provided, and the laser light is emitted so that it is safe even if the device does not operate. A shutter member (21P) that blocks the optical path L may be provided. As shown in FIG. 10, the shutter member (21P) is swingably suspended on a support member 19 in the optical case 17, and the upper case 1U is opened to be opened as shown by a chain double-dashed line in FIG. When tilted, it rotates in the direction of arrow P relative to the upper case 1U by its own weight to block the optical path L, and when the upper case 1U is closed and brought into a horizontal state as shown by the solid line in FIG. It is configured to rotate in the direction of arrow Q with respect to the upper case 1U by its own weight to release the blocking of the optical path L.

As a result, even if the light source 12 should not be stopped when the upper case 1U is opened, the shutter member 21P blocks the optical path L, so that safety is ensured.

The upper case 1U is locked by the lock mechanism 50 in the closed position as shown in FIG. The lock mechanism 50 includes an engagement portion 55 provided on the upper case 1U side and a lock lever 51 provided on the lower case 1L side.

In the lock lever 51, the hook portion 52 engages with the engaging portion 55 by the urging force of the spring 53 to lock (lock) the upper case 1U in the closed position in a state where it is not pressed from the side, and When the pressing force F is applied from one side, the hook portion 5 rotates counterclockwise in FIG. 9 around the support shaft 54 while resisting the urging force of the spring 53.
2 is disengaged from the engaging portion 55, and the upper case 1
It is configured so that U is in a rotation-free state.

[0012]

By the way, in the above-mentioned conventional electrophotographic apparatus, when the upper case 1U or the like is externally vibrated when the upper case 1U is closed from the open state, the shutter member 21P is exposed. Swings and the interruption of the optical path L is released, and the laser light may leak out of the main body case 1, which is a safety problem.

In the electrophotographic apparatus, the optical system 11
Is provided in the upper case 1U, the upper case 1
It is difficult to improve the positional accuracy with respect to the photoconductor 6 due to thermal deformation of U, backlash of the rotary connecting portion 3, and the like. Therefore, the optical system 11 may be provided on the lower case 1L side, but in such a case, attaching the shutter member 21P having the above configuration to the optical system 11 does not help, so the shutter member 21P is not useful.
Instead of the above, there is a demand for the development of a technique capable of blocking / unblocking the optical path L according to opening / closing of the upper case 1U.

As one measure to meet such a request, an electric type in which the opening / closing of the upper case 1U is detected by a micro switch or the like, and the motor is driven based on the detection result to move the shutter member to interrupt / unblock the optical path L It is conceivable to provide the optical path blocking device. However, this complicates the device, increases the size, and increases the cost.

In view of the above-mentioned circumstances, an object of the present invention is to reduce the size and cost, and to reliably cut off the optical path when the upper case is opened irrespective of the installation position of the optical system and to cut off the laser beam. An object of the present invention is to provide an electrophotographic apparatus capable of preventing light from leaking to the outside.

[0016]

An electrophotographic apparatus according to the present invention comprises a main body case including a lower case and an upper case openably and closably mounted on the lower case, and an optical case provided in the main body case. In an electrophotographic apparatus including an optical system including a light source and an optical component built in the optical case and capable of irradiating a laser beam emitted from the light source to the outside through an optical path in the optical case, the light is emitted from the light source. A shutter member having a hole for passing a laser beam, which can be positioned and held at either a blocking position for blocking the optical path or a blocking release position for releasing the blocking of the optical path by aligning the hole with the optical path, and the shutter member Urging means for urging the upper case to be positioned and held in the shut-off position, and the closing force acting on the upper case when the upper case is in a closed state. It positioned holding the unblocking position by applying an external force to the coater member, and wherein the shutter member when the upper case is opened is provided with actuating means to allow the return to the blocking position.

[0017]

In the present invention having the above structure, when the upper case is opened, the holding of the shutter member by the actuating means is released, and the shutter member is returned to the blocking position by the urging force of the urging means. In this way, since the shutter member is biased by the biasing means and positioned and held at the blocking position, it does not move inadvertently even if vibration from the outside is applied, and the state in which the optical path is securely blocked is ensured. maintain.

When the upper case is closed from the open state, the operating means applies an external force to the shutter member using the closing force acting on the upper case to position and hold the shutter member in the blocking release position. This allows the laser light emitted from the light source to
The light can be emitted to the outside through the optical path in the optical case without being blocked by the shutter member.

Therefore, by utilizing the urging force of the urging means and the closing force acting on the upper case, the optical path of the optical system can be surely blocked / unblocked according to the opening / closing of the upper case, and the size can be reduced. In addition, safety can be secured while lowering costs.

[0020]

Embodiments of the present invention will be described with reference to the drawings. (First Embodiment) As shown in FIGS. 1 to 4, the present electrophotographic apparatus includes a main body case 1, an optical system 11, a light source 12, optical parts (slits 13, lenses 14A and 14B, a polygon mirror 16, etc.), an optical system. The case 17] has the same basic configuration as the conventional example (FIG. 9), but the shutter member 21, the biasing means (31), and the operating means (corresponding to the optical system 11 provided in the lower case 1L). 41) and urging means (3
Utilizing the urging force of 1) and the closing force acting on the upper case 1U, the optical path L of the optical system 11 can be blocked / unblocked according to the opening / closing of the upper case 1U.
The same components as those in the conventional example (FIG. 9) are designated by the same reference numerals, and the description thereof will be simplified or omitted.

As shown in FIGS. 2 and 3, the shutter member 21 has a hole 22 through which the laser light emitted from the light source 12 of the optical system 11 passes, and a blocking position P for blocking the optical path L.
1 and the hole 22 are provided on the lower case 1L side so that they can be positioned and held at any one of the blocking release positions P2 that align with the optical path L and release the blocking of the optical path L.

In this embodiment, the shutter member 21 is a guide penetratingly provided in the upper part of the optical case 17 so that the optical path L between the light source 12 and the slit 13 of the optical system 11 can be blocked / unblocked. It is fitted in the hole 25 so as to be vertically movable. Further, the hole 22 of the shutter member 21 is provided with the light source 1
It is formed so as to have an opening area larger than the cross-sectional area of the laser light emitted from the laser light 2 and traveling along the optical path L. Also,
The blocking position P1 and the blocking release position P2 should be at least the hole 2
It is selected to be separated by 2 diameters.

Further, the urging means (31) is means for urging the shutter member 21 to be positioned and held at the blocking position P1 as shown in FIG. In the present embodiment, the urging means is formed by the urging spring 31 interposed between the upper surface of the optical case 17 and the upper bent portion 23 of the shutter member 21.

The operating means (41) is the upper case 1
When U is in the closed state, the closing force acting on the upper case 1U is used to apply an external force to the shutter member 21 to position and hold it in the blocking release position P2, and when the upper case 1U is opened, the shutter is released. It is provided in the main body case 1 so as to allow the member 21 to return to the blocking position P1 by the urging force of the urging means (31).

In this embodiment, the operating means is the upper case 1.
It is composed of a pressing rib 41 integrally formed on the back surface of U so as to press the shutter member 21. That is, when the upper case 1U is locked by the lock mechanism 50 in the closed position shown by the solid line in FIG. 1, the pressing rib 41 has a closing force acting on the upper case 1U (the weight of the upper case 1U and the lock mechanism). (Holding force of 50) is used to press and hold the shutter member 21 down to the blocking release position P2, and separate it from the shutter member 21 when the upper case 1U is opened. Has been formed.

Next, the operation of this embodiment will be described. When the upper case 1U is opened, the pressing rib 41 separates from the shutter member 21. As a result, the shutter member 21 is blocked by the urging force of the urging spring 31 to the blocking position P1.
Will be returned to. In this way, since the shutter member 21 is biased by the biasing spring 31 and positioned and held at the blocking position P1, the shutter member 21 does not move carelessly even if vibration or the like is applied from the outside, and the optical path L is reliably moved. Maintain the cutoff state.

When the upper case 1U is closed from the open state, the pressing rib 41 presses the shutter member 21 by using the closing force acting on the upper case 1U to position and hold the shutter release position P2. As a result, the laser light emitted from the light source 12 passes through the optical path L in the optical case 17 without being blocked by the shutter member 21, and the external photoconductor 6 is exposed.
Can be irradiated.

According to this embodiment, however, the light source 12
Has a hole 22 for passing the laser beam emitted from
A shutter member 21 that can be positioned and held at either a shutoff position P1 or a shutoff release position P2 that shuts off the shutter, a biasing spring 31 that biases the shutter member 21 to be positioned and held at the shutoff position P1, and an upper case. When 1U is in a closed state, the closing force acting on the upper case 1U is used to apply an external force to the shutter member 21 to position and hold the shutter release position P2, and the upper case 1U is closed.
When the shutter is opened, the shutter member 21 closes the blocking position P1.
Since the pressing rib 41 for allowing the return of the upper case 1U is provided, the urging force of the urging spring 31 and the closing force acting on the upper case 1U are used to perform the optical operation according to the opening / closing of the upper case 1U. The optical path L of the system 11 can be reliably blocked / unblocked. As a result, when the upper case 1U is opened, the optical path L of the optical system 11 can be reliably cut off and the laser light can be prevented from leaking to the outside while achieving downsizing and cost reduction.

Further, since the shutter member 21 is configured to be guided in the vertical direction while the lateral position is restricted by the guide hole 25 of the optical case 17, the shutter member 21 can be moved up and down without rattling to further smoothly and surely block the optical path L. -Can be unblocked.

Further, since the biasing means is formed by the biasing spring 31, the structure is further simplified and the cost can be further reduced.

Further, since the operating means is formed by the pressing rib 41 integrally formed on the back surface of the upper case 1U, the structure can be further simplified and the cost can be further reduced.

In the first embodiment, the actuating means is constituted by the pressing rib 41, but it may be constituted by the engaging projection 43 provided on the upper portion of the shutter member 21 as shown in FIG.

When the upper case 1U is closed, the engaging projection 43 is pushed down while being in contact with the back surface of the case 1U to position and hold the shutter member 21 at the blocking release position P2, and when the upper case 1U is opened. It is formed to be separated from the back surface of the case 1U.

With this configuration, it is possible to reliably prevent the laser light from leaking to the outside when the upper case 1U is opened while further simplifying the device.

Further, the actuating means may be formed by utilizing a boosting mechanism 45 as shown in FIG. This booster mechanism 45
Includes a lever 46, one end of which is rotatably supported on the upper surface of the optical case 17 through a support member 47, and the protrusion 24 of the shutter member 21 is connected to the center thereof, and the upper case 1U.
It is composed of a pressing rib 41A formed on the back surface of the upper case 1U so that the other end (free end) of the lever 46 can be pressed at the time of closing to position and hold the shutter member 21 at the blocking release position P2.

With such a structure, it is possible to prevent the laser light from leaking to the outside when the upper case 1U is opened, while achieving downsizing and cost reduction.
The upper case 1U can be closed with a lighter force.

(Second Embodiment) A second embodiment is shown in FIGS. 7 and 8. In the electrophotographic apparatus according to the second embodiment, the optical system 11, the shutter member 21, and the biasing spring 31 as the biasing means are provided on the upper case 1U side, and the pressing member 42 as the operating means is provided on the lower case 1L side. It is configured to be provided in. The first embodiment (FIGS.
The same components as those in FIG. 6) are designated by the same reference numerals, and the description thereof will be simplified or omitted.

The shutter member 21, as shown in FIG.
It has a hole 22 for passing the laser beam emitted from the light source 12, and is vertically movably fitted into a guide hole 25A formed in the lower surface of the optical case 17. A biasing spring 31 is interposed between the lower bent portion 26 of the shutter member 21 and the lower surface of the optical case 17. The biasing spring 31 elastically supports the shutter member 21 so as to be positioned and held at the blocking position P1.

The pressing member 42 contacts the lower bent portion 26 of the shutter member 21 when the upper case 1U is closed and can push the shutter member 21 up to the blocking release position P2, and when the upper case 1U is opened. It is provided so as to be separated from the shutter member 21.

With this structure, when the upper case 1U is opened, the pressing member 42 separates from the shutter member 21. This causes the shutter member 21 to move the biasing spring 31.
Is returned to the cutoff position P1. Here, since the shutter member 21 is positioned and held at the blocking position P1 by the urging force of the urging spring 31, it does not move carelessly even if it is applied from the outside due to vibration or the like, and reliably blocks the optical path L. Stay in the state.

When the upper case 1U is closed from the open state, the pressing member 42 presses the shutter member 21 using the closing force acting on the upper case 1U to position and hold the shutter release position P2.

Therefore, by utilizing the urging force of the urging spring 31 and the closing force acting on the upper case 1U, the optical path L of the optical system 11 is surely shut off according to the opening / closing of the upper case 1U.
It can be unblocked.

In the above first and second embodiments,
The actuating means (41, 42, 43, 45) is configured to block / unblock the optical path L between the light source 12 and the slit 13, but blocks / blocks the other part of the optical path L in the optical case 17. It may be configured to cancel.

[0044]

According to the present invention, a shutter member that can be positioned and held at either the optical path blocking position or the blocking release position, and a biasing means that biases the shutter member to be positioned and held at the blocking position. , When the upper case is in a closed state, the closing force acting on the upper case is used to apply an external force to the shutter member to position and hold it in the blocking release position, and when the upper case is opened, the shutter member is Since the actuating means for permitting the return to the shut-off position is provided, the optical system is opened or closed depending on whether the upper case is opened or closed by utilizing the urging force of the urging means and the closing force acting on the upper case. The optical path can be reliably blocked / unblocked. As a result, it is possible to prevent the laser light from leaking to the outside by surely blocking the optical path of the optical system when the upper case is opened while achieving downsizing and cost reduction.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a first embodiment of the present invention.

FIG. 2 is a view showing a state in which the upper case is closed and the shutter member is positioned and held at the blocking release position in the same manner.

FIG. 3 is likewise a view showing a state in which the upper case is opened and the shutter member is positioned and held at the blocking position.

FIG. 4 is a plan view for explaining the positional relationship between the shutter member and the light source.

FIG. 5 is also a diagram for explaining a modified example of the operating means.

FIG. 6 is a diagram for explaining another modification of the operating means.

FIG. 7 is a diagram for explaining the second embodiment of the present invention.

FIG. 8 is a diagram for explaining the positional relationship between the pressing member and the shutter member.

FIG. 9 is a partially cutaway side view for explaining the conventional configuration of the electrophotographic apparatus.

FIG. 10 is also a perspective view for explaining a shutter member capable of blocking / unblocking the optical path of the optical system.

[Explanation of symbols]

 1 Main Body Case 1L Lower Case 1U Upper Case 11 Optical System 12 Light Source 21 Shutter Member 22 Hole 31 Biasing Spring (Biasing Means) 41 Pressing Rib (Operating Means)

Claims (1)

[Claims] 1. A main body case including a lower case and an upper case openably and closably provided on the lower case, an optical case provided in the main case, a light source and an optical component built in the optical case. An electrophotographic apparatus comprising an optical system capable of irradiating a laser beam emitted from a light source to the outside through an optical path in an optical case, having a hole for passing the laser beam emitted from the light source, And a shutter member capable of positioning and holding the shutter member at a blocking position for blocking the optical path and a blocking releasing position for canceling the blocking of the optical path by aligning the hole with the optical path, and biasing the shutter member to be positioned and held at the blocking position. The biasing means and the closing force that acts on the upper case when the upper case is in the closed state apply an external force to the shutter member to position it in the blocking release position. An electrophotographic apparatus, comprising: an actuating unit which holds the shutter member and allows the shutter member to return to the blocking position when the upper case is opened.