JP2002067461A - Door opening/closing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a door opening/closing device of imaging apparatus in which a door can be locked forcibly during operation of a machine. SOLUTION: The door opening/closing device comprises a member 2 to be locked provided on the inside of the door 1 of an imaging apparatus, a shape memory alloy 3 being deformed thermally into a prestored hooked shape upon power supply to lock the member 2 being locked, and a shape memory alloy control section for feeding a current to the shape memory alloy 3 simultaneously with current supply to a drive system motor from a power supply.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a door opening / closing apparatus for locking a door by using a shape memory alloy, and more particularly to a door opening / closing apparatus for an image forming apparatus.

[0002]

2. Description of the Related Art An image forming apparatus such as a copying machine or a printer is provided with a door for handling a paper jam or for performing maintenance of internal units. When the machine (image forming apparatus) is operating, the door is closed, and when the machine is stopped, the door is opened to perform paper jam processing and various maintenance.

[0003]

Since it is dangerous if a user opens a door and touches an internal unit during operation of an image forming apparatus, an interlock is usually provided at a joint between the door and the apparatus main body. A switch is attached so that when a user opens a door when the power is turned on, an interlock switch is activated, and when the user touches the power, a power supply of a dangerous drive system or the like is turned off by hardware.

[0004] However, even in the case where a technology for securing safety by providing an interlock switch is adopted,
If the interlock switch fails and stops working,
There was a risk that the user could open the door while the machine was running.

Accordingly, the present invention focuses on shape memory alloys.
For example, Japanese Unexamined Patent Publication No. 3-192236 discloses a camera back cover opening / closing control device comprising a shape memory alloy which returns to an original shape stored in advance by being energized and generates heat. It is shown.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a door opening / closing device of an image forming apparatus which can forcibly lock a door during operation of a machine by using a shape memory alloy for a lock portion of the door. .

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a locked member provided inside a door of an image forming apparatus is stored in advance by generating heat when energized. A shape memory alloy that changes into a shape and locks the member to be locked, and a shape memory alloy control unit that controls current to flow to the shape memory alloy at the same time that current flows from the power supply to the drive system motor. Door opening and closing device.

[0008] In order to achieve the above object, a second aspect is provided.
The invention described in the above is the door opening and closing device according to the first aspect,
In response to a door lock input from the operation unit, the shape memory alloy control unit performs control to supply power to the shape memory alloy when the power is turned on regardless of whether or not the image forming apparatus is operating.

In order to achieve the above object, a third aspect of the present invention is provided.
The invention described in the above is the door opening and closing device according to the first aspect,
A heater control unit and a heater for energizing the shape memory alloy based on a heater-on input from the operating unit and simultaneously energizing under the control of the heater control unit to heat the shape memory alloy are provided. is there.

According to the first aspect of the present invention, a current flows from the power supply to the shape memory alloy according to an instruction from the shape memory alloy control unit at the same time that a current flows to the drive system motor of the image forming apparatus, and heat is generated. Changes to a previously stored shape, for example, a hook (key) shape, and the locked member provided on the door of the image forming apparatus is locked.

According to the second aspect of the present invention, the door is locked in response to an input from the operation unit by the user even when the power is on, except during operation.

According to the third aspect of the present invention, when the user performs a heater-on input operation from the operation unit, when energizing the shape memory alloy, current flows from the power supply to the heater in accordance with an instruction from the heater control unit, and the heater is heated. You. As a result, the shape memory alloy quickly changes to the previously stored shape.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of a door internal structure in a door opening and closing device of the present invention, FIG. 2 is a view showing a state of a lock mechanism when a drive system motor is turned off, and FIG.
FIG. 4 is a diagram illustrating a state of a lock mechanism when a drive system motor is turned on.

As shown in FIG. 1, a U-shaped locked member 2 made of a non-deformable member is mounted inside a door 1. The door 1 has a fixed end as a center, and the end side to which the locked member 2 is attached is opened and closed.

As shown in FIGS. 2 and 3, the lock mechanism of the door 1 includes a member to be locked 2 and a shape memory alloy (lock member) 3. This shape memory alloy 3
It has the property of generating heat when an electric current is applied, and has the property of changing to a previously stored shape when it exceeds a certain temperature.

At the end of the shape memory alloy 3, an electric wire 4 for flowing a current to a shape memory alloy 3 from a power supply at the same time as an instruction from a shape memory alloy control unit to be described later at the same time as a current flows to a drive system motor described later. It is connected. It is assumed that the end of the shape memory alloy 3 on the side connected to the electric wire 4 is fixed.

When no current flows through the drive system motor, no current flows through the shape memory alloy 3, so that no heat is generated and the shape does not change. That is, as shown in FIG. 2, it is linear and located on the side surface of the locked member 2. for that reason,
The locked member 2 is not locked, and the door 1 can be opened and closed.

On the other hand, when a current flows through the drive system motor, a current simultaneously flows from the power supply to the shape memory alloy 3 and the shape memory alloy 3 self-heats, which is stored in advance as shown in FIG. The locked member 2 is locked by changing to the key shape, that is, the key shape. Therefore, door 1
Can not be opened and closed from the outside.

FIG. 4 is a block diagram showing a first embodiment of a control system in the door opening / closing device of the present invention. In order to operate the drive system, a signal is output from the CPU 50 to the power supply 51, and at the same time, a signal is sent from the CPU 50 to the shape memory alloy control unit 52 to pass a current to the shape memory alloy 3, and the shape memory alloy control unit 52 receiving the signal is output. From the power supply 51.
The power supply 51 that has received signals from the CPU 50 and the shape memory alloy control unit 52 supplies a current to the drive system motor 53 and the shape memory alloy 3. The following operation is as described above.

With this control system, it is possible to prevent the door 1 from being opened only when the image forming apparatus is operating.

FIG. 5 is a block diagram showing a second embodiment of the control system in the door opening / closing device according to the present invention. This control system adds an operation unit 54 to the block shown in FIG. 4 so that, for example, even when the drive system is stopped when the power is turned on, such as during standby, the user inputs a door lock on from the operation unit 54 even when the drive system is stopped. It was made possible. When an input operation for door lock-on is performed from the operation unit 54, the signal is transmitted to the CP.
The signal is input to U50, and thereafter, the control operation described in FIG. 4 is performed.

The shape memory alloy control unit 52 is set so as not to receive a door lock-off signal from the operation unit 54 when the drive system is operating. In this control system, the door 1 can be locked even when the power is on, except when the power is on, by the user performing the door lock-on operation from the operation unit 54.

FIG. 6 is a block diagram showing a third embodiment of the control system in the door opening / closing device of the present invention. This control system is obtained by adding a heater control unit 55 and a heater 56 to the block shown in FIG. The heater 56 that is turned on and off by the heater control unit 55 is provided so as to contact the shape memory alloy 3 or in the vicinity thereof.

When the image forming apparatus enters the operation mode with the heater ON input from the operation unit 54, the CP
From U50, the shape memory alloy controller 52 and the heater controller 55
, A signal is transmitted from each control unit to the power supply 51, and a signal is similarly output from the CPU 50 to the power supply 51. A current flows from the power source 51 to three places of the drive system motor 53, the shape memory alloy 3, and the heater 56 at the same time.

When a current flows through the shape memory alloy 3, the shape memory alloy 3 self-heats and changes to the stored key shape as shown in FIG. 3, as described above. This heat is transferred to the shape memory alloy 3
Is also transmitted to Therefore, the shape memory alloy 3 quickly reaches the predetermined temperature and changes its shape in a shorter time than when the heater 56 is not provided.

According to this control system, the door can be locked at the same speed as in a normal environment even in a cold environment.

[0027]

According to the first aspect of the present invention, a current flows from the power supply to the shape memory alloy according to an instruction from the shape memory alloy control unit at the same time as the current flows to the drive system motor of the image forming apparatus, thereby generating heat. Then, the shape memory alloy changes to the previously stored shape, and the locked member provided on the door of the image forming apparatus is locked. Therefore, during operation of the image forming apparatus, the door cannot be opened, and safety is ensured.

According to the second aspect of the present invention, the door is locked in response to an input from the operation unit by the user even when the power is on, except during operation. Therefore, the same effect as described above is achieved.

According to the third aspect of the present invention, when the user performs a heater-on input operation from the operation unit, when power is supplied to the shape memory alloy, a current flows from the power supply to the heater in accordance with an instruction from the heater control unit, and the heater is turned on. Heated. As a result, the shape memory alloy quickly changes to the state stored in advance. Therefore, in addition to the same effect as described above, the door can be quickly locked even in a cold environment.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a door internal structure in a door opening and closing device of the present invention.

FIG. 2 is a diagram illustrating a state of a lock mechanism when a drive system motor is off.

FIG. 3 is a diagram illustrating a state of a lock mechanism when a drive system motor is turned on.

FIG. 4 is a block diagram showing a first embodiment of a control system in the door opening / closing device of the present invention.

FIG. 5 is a block diagram showing a second embodiment of the control system in the door opening / closing device of the present invention.

FIG. 6 is a block diagram showing a third embodiment of the control system in the door opening / closing device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Door 2 Locked member 3 Shape memory alloy 4 Electric wire 50 CPU 51 Power supply 52 Shape memory alloy control unit 53 Drive system motor 54 Operation unit 55 Heater control unit 56 Heater

Claims (3)

[Claims] 1. A locked member provided inside a door of an image forming apparatus, a shape memory alloy which generates heat by energization and changes to a previously stored shape to lock the locked member, and a drive system from a power supply. A door opening / closing device, comprising: a shape memory alloy control unit that controls a current to flow to a shape memory alloy at the same time that a current flows to a motor. 2. The door opening / closing device according to claim 1, wherein the shape memory alloy control section controls the power supply to the shape memory alloy when the power is turned on irrespective of the operation of the image forming apparatus by the door lock input from the operation section. Door opening and closing device characterized by performing. 3. The door opening / closing device according to claim 1, wherein a current is supplied to the shape memory alloy based on a heater-on input from the heater control unit and the operation unit, and at the same time, power is supplied to the shape memory alloy under the control of the heater control unit. And a heater for heating the door.