JPH02201362A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent a contact mechanism from being welded and destroyed without using a large-capacity contact mechanism which withstands excessive rush current by shutting off electrical supply from a power source to a light source when it is recognized, based on a detecting signal outputted from a position detecting means, that an original platen is not in an exposure starting position. CONSTITUTION:When the prescribed signal is not outputted from a switch 119 detecting the original platen exposing start position, that is, when it is recognized that the original platen is not in the specified position, a switching means 107 is opened to shut off electrical supply from the power source (+V) to the light source; even if a lid body 31 for the replacement of a halogen lamp 5a is opened and the contact mechanisms 102a and 102b are opened, a large rush current is not generated when the light source starts to drive, because the light source 5 is not driven. Thus, the damage to the contact mechanisms, such as welding, can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus, and particularly to an image forming apparatus capable of forming a full-color copy image using a photosensitive recording medium such as microcapsule paper. The present invention relates to an image forming apparatus.

[Conventional technology]

An overview of this type of image forming apparatus is generally described below. That is, a document is sandwiched between a document table cover and document table glass that are provided on the upper part of the image forming apparatus so as to be able to move back and forth in a straight line, and a halogen lamp and a semi-cylindrical reflector are used to illuminate the document. The document is scanned by emitting light from a light source and moving the document table cover and document table glass.

The light that scanned the original is guided by various optical systems to an exposure table in the center of the image forming apparatus, where it forms an image on one side of the supplied microcapsule paper, forming a latent image. Let it form. The imaged microcapsule paper is then pressed onto the supplied developer paper in a pressure developing device to form a visible image on the developer paper, and the developer paper with the visible image formed thereon is transferred to a heat fixing device. The image is then fixed and then ejected from the device.

[Problem to be solved by the invention]

Incidentally, in the conventional image forming apparatus having the above-mentioned configuration, a lid body is attached to the main body of the apparatus to open the inside of the apparatus for maintenance of various devices such as replacing the halogen lamp. The lid could be opened and closed by moving the document table in one direction toward the end by operating a document table movement button provided on the operation section of the main body of the device. .

However, when various devices such as the halogen lamp are being operated, opening the lid makes it possible to touch parts to which high voltage is applied, which is extremely dangerous. At the same time, an interlock circuit was installed to cut off the power supply to the halogen lamp using an AC relay or other device.

However, since a large current of 70 to 80 A flows as an inrush current at the start-up of the halogen lamp,
If the interlock circuit is activated when the document table is moved and the lid is opened at the start of the halogen lamp drive, there is a problem that the contacts of the AC relay may be welded and destroyed by arc discharge or the like. Therefore, in order to prevent such problems from occurring, a method of using a large-capacity AC relay that can sufficiently withstand the above-mentioned inrush current value in the interlock circuit has been considered, but this method increases the cost. There was a problem with inviting people.

The present invention was devised in view of the above, and its purpose is to ensure sufficient safety even when the lid is opened and each part of the device becomes accessible, and to provide a large-capacity It is an object of the present invention to provide an image forming apparatus whose contacts are not damaged by lava even without using an AC relay and whose cost is low.

[Means to solve the problem]

The features of the present invention for achieving the above object include: a document table that can reciprocate with respect to an apparatus main body; a position detection means for detecting whether or not the document table is at a predetermined specific position; a light source that emits light toward the light source; a switching device that connects/connects the light source and a power source that supplies power to the light source;
a lid body that is attached to the main body of the apparatus so as to be openable when the document table is not at a specific position; and a lid body that is connected to the lid body to open between the light source and the power source when the lid body is opened. and a contact mechanism configured to open the switching means when it is recognized that the document table is not at a specific position based on a detection signal output from the position detection means, thereby reducing the power supply from the power source. An image forming apparatus includes a control means for cutting off power supply to a light source.

[Effect]

According to the above configuration, when it is recognized that the document table is not at a specific position based on the detection signal output from the position detection means, the switching means is opened to cut off the power supply to the light source from the power supply. As a result, even if the lid is opened and the contact mechanism is in the open state, the light source is not driven, so a large rush current will not be generated at the start of the light source drive, and damage such as welding of the contact mechanism can be prevented. became.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An image forming apparatus according to the present invention will be described below with reference to FIG. 1, which shows a schematic configuration of an embodiment of a photosensitive and pressure sensitive copying machine capable of full-color copying.

As already mentioned, in the photosensitive and pressure sensitive copying machine 1 according to this embodiment (hereinafter referred to as "copying machine 1" for simplicity),
A latent image forming medium, ie, a photosensitive pressure sensitive paper consisting of microcapsule paper and developer paper is used.

A movable original platen glass and an original platen cover 3 are provided on the top plate of the copying machine 1, and a desired original 4 is set face down on the original platen glass 2. ing. A light source 5, such as a halogen lamp, for example, is disposed in an upper area within the copying machine 1. The light source 5 is
Light is irradiated in a line toward the document table glass 2 through a slit hole formed on the top surface of the copying machine 1, and the irradiated light is transmitted through the transparent document table glass 2. That is, the light emitted from the light source 5 is reflected by the original 4 set on the original platen glass 2, and as the original platen glass 2 moves, the original 4 is exposed and scanned.

The filter 6 receives the light reflected from the original 4 and adjusts the color tone of the copied image, and then sends it to the projection lens 7 . The projection lens 7 receives the light whose color tone has been adjusted by the filter 6 and projects it onto a pair of reflecting mirrors 8 and 9.

The pair of reflecting mirrors 8.9 are attached to a mirror mounting plate, and are configured so that the optical path length and focus can be adjusted by finely adjusting the mounting position of the mirror mounting plate. A pair of reflection mirrors 8.9 are connected to the projection lens 7.
The direction of the light is changed as shown in FIG. 1, and as described later, the exposure stage 1
The image is formed on a portion of the elongated microcapsule paper 11 positioned along 0.

On the other hand, the above-mentioned long microcapsule paper 11 is wrapped around the cartridge shaft 12a in the copying machine main body 1.
The cartridge 12b is housed in a cartridge 12b that is removable from the cartridge 12b. One end of the microcapsule paper 11 reaches the winding shaft 15 via a feed roller 14a, a guide roller 14b, a feed roller 14c, a pressure developing device 13, and a separation mechanism 14d. That is, the microcapsule paper 11 coming out from the lower part of the cartridge 12b is transferred to the feed roller 14a.
After passing under the exposure table 10 while being guided by the 1 guide roller 14b, it is supplied to the pressure developing device 13. Further, the microcapsule paper 11 that has passed through the pressure developing device 13 is guided to the feed roller 14C1 separation mechanism 14d and the meandering adjustment roller 14e, and then wound onto the winding shaft 15. Note that the unexposed microcapsule paper 11 after leaving the cartridge 12b is maintained in an unexposed state by the light shielding cover 12c. The conveying speed of the microcapsule paper 11 is controlled to match a predetermined speed, that is, the moving speed of the document table glass 2. Therefore, latent images of predetermined lines of the document 4 are sequentially formed on the microcapsule paper 11 as it passes through the exposure table 10.

Below the pressure developing device 13, a paper feeding cassette 17 constituting a paper feeding device is detachably attached to the copy binding t*1, and a suction cup type cassette that sucks paper using negative pressure suction is installed. A paper feeding mechanism 18 is provided. Paper cassette 1
A color developing paper 16 is housed inside 7 as a recording device.

The color developer paper 16 is taken out one by one by the paper feed mechanism 18 and conveyed by the feed roller 19a1 and the pinch roller 19b, and is then transported to the color developer paper rollers 19c, 19d and the registration gate 1.
After the tip end is aligned by 9e, it is carried into the pressure developing device 13.

Through the process described above, the microcapsule paper 11 and the color developer paper 16 are supplied to the pressure developing device 13 in a tightly packed and integrated state. In this pressure developing device 13, the microcapsule surface of the microcapsule paper 11 on which the latent image has been formed and the developer coated surface of the color developer paper 16 are brought into contact with each other on the inside and are integrated into a small diameter roller 13a and backed up. The roller 13b1'' is sandwiched and pressure is applied.

This pressure destroys the unexposed microcapsules and forms a visible image on the developer paper 16.

After the microcapsule paper 11 and the color developer paper 16 that have come out of the pressure development device 13 are separated by a separation mechanism 14d, the color development of the color developer paper 16 is promoted by the heat roller 20a of the heat fixing device 20, and an image is formed. After that, the paper ejection roller
The paper is then delivered to the paper discharge tray 21. The separated microcapsule paper 11 is wound around the winding shaft 15 by passing through the meandering adjustment roller 14e.

FIG. 2 is a circuit diagram of a control system included in an image forming apparatus according to an embodiment of the present invention.

In FIG. 2, the connection terminal is connected to an external power source (not shown) of AC 100 to 240V. The contact mechanism or interlock circuit 109 has two contacts '102a.
, 102b and a relay drive unit 105, and an interlock switch 107 connected to the relay drive unit 105. The two contacts 102a and 102b are connected to the connection terminal 101 and the connection terminal 10.
When the relay drive section 105 is in an excited state due to the closing of the interlock switch 107, the relay drive section 105 is closed and power is supplied to the halogen lamp 5a from the external power supply side. When the halogen lamp 5a is in a demagnetized state by opening the interlock switch 107, it is opened to cut off power supply to the halogen lamp 5a from the external power source side.

The interlock switch 107 is three-dimensional, for example, a third
It operates in conjunction with a cover body 31 for halogen lamp replacement shown in the figure, and when the cover body 31 is opened, it is in the open state and the relay drive unit 105 from the power supply unit (+V) is operated. It is configured to cut off the power supply. Note that in this embodiment, the interlock switch 107
As shown in FIG. 3, these are provided at the upper part of the main body of the apparatus, that is, at a portion facing the bottom surface of the original platen glass 2, and at the above-mentioned lid 31. As described above, the interlock switch 107 is provided to ensure the safety of the device by cutting off the power supply from the external power source when the lid 31 is opened.

Semiconductor switching means, i.e. solid state relays (
The SS relay (hereinafter referred to as "SS relay") 111 is provided to connect/disconnect the halogen lamp 5a and the external power source. The SS relay 111 is in a conductive state during normal operation, and is controlled to be in a non-conductive state by a drive command signal output from a control means, ie, a CPU 121, which will be described later.

Position detection means, that is, document platen exposure start position detection switch 11
9 is connected to the CPU 121.

The document platen exposure start position detection switch 119 closes only when the document platen glass 2 is at a predetermined exposure start position (that is, the home position of the document platen glass 2, for example), and outputs a predetermined detection signal (logic A voltage signal of level "H") is output to the CPU 121. In this embodiment, the document platen exposure start position detection switch 119 is
It is attached to the part shown in the figure.

The light amount sensor 113 detects the amount of light emitted from the light source 5 (including the halogen lamp 5a) described above, and
It is designed to output a light amount detection signal. R.A.
M117 stores necessary data for a predetermined period under the control of CPU121. The ROM 115 stores control programs and nonvolatile fixed data.

The CPU 121 performs arithmetic operations and logical operations. C.P.
When U121 recognizes that the predetermined detection signal is no longer output from document platen exposure start position detection switch 119, it outputs a drive stop command signal to SS relay 111 to change SS relay 111 from a conductive state to a non-conductive state. control, and cuts off the power supply to the halogen lamp 5a from the external power supply side. The CPU 121 controls the SS relay 111 based on the light tEl output signal output from the light amount sensor 113 and the light amount reference value data stored in the ROMI 15.
The drive of the halogen lamp 5a is variably adjusted, thereby variably adjusting the amount of power supplied from the external power source to the halogen lamp 5a. The CPU 121 includes a document table moving device (not shown)
By controlling the drive of the document platen glass 2, the original platen glass 2 is caused to reciprocate.

Next, the control operation of the above-mentioned configuration will be explained mainly with reference to the flowchart shown in FIG.

The operator controls the image forming device (not shown).
By turning on a power supply switch (not shown) provided in the image forming apparatus, the image forming apparatus enters a standby state, and the CPU 121 also starts its control operation. Next, when a signal indicating that the operator has operated a copy start switch (not shown) provided on the input panel (not shown) is inputted, the CPU 121 performs a series of image forming operations and moves the document table moving device ( (not shown) and turn on the original platen return clutch (not shown).
to return the original platen glass 2 to its home position (step 401).

When a detection signal indicating that the original platen glass 2 has returned to the home position is output from the original platen exposure start position detection switch 119 in step 401, the original platen return clutch is turned OFF (step 402), and the original is actually read. In order to confirm whether or not the table glass 2 has stopped at the exposure start position, until several hundred m5ec have elapsed (step 403).

After several 100 m5ec have passed, it is checked again whether or not the predetermined detection signal is output from the document glass exposure start position detection switch 119 (step 404). When it is recognized that there is no one, the process moves to step 405. In other words, although the document glass 2 has returned to its home position, it has since been moved out of the home position by an ovulator or the like, so a series of error processes due to the forced movement of the document table are performed. The process then moves to an error handling routine (step 405).

At step 404, the original platen exposure start position detection switch 1 is
When it is recognized that a predetermined detection signal is output from the external power source 19, power supply to the halogen lamp 5a from the external power source side is started to start driving the halogen lamp 5a.This is used for start-up work when driving the halogen lamp 5a. Clear the rising control end flag associated with the flag and clear the rising control time counter (step 406).
.

After the processing operation shown in step 406 is completed, a flag for driving the halogen lamp 5a is set, and preparations are made so that the halogen lamp 5a can be driven at any time, that is, can be energized (step 407). . After preparing to drive the halogen lamp 5a at any time in step 407, it is determined whether or not the rise control end flag cleared in step 406 is set (step 408), and it is recognized that it is not set. In some cases, the process moves to step 409 regardless of whether or not the halogen lamp 5a is actually energized. That is,
In step 404, it is confirmed whether or not a predetermined detection signal is being outputted from the document platen exposure start position detection switch 119 in the same way as in the case of Tato. If it is recognized that there is no
), the CPU 121 immediately stops the halogen lamp 5a by outputting a drive stop command signal to the SS relay 111.
(Step 410), and then the process moves to an error processing routine to perform a series of error processing due to the forced movement of the document table (Step 411).
).

When it is recognized in step 408 that the start-up control end flag is set, the document glass 2 is waiting at its home position and is at the appropriate exposure start position, so the document glass moving device (not shown) ) will output a drive command signal to start a series of exposure operations (
Step 412).

As explained above, according to an embodiment according to the present invention,
In the process of returning the original platen glass 2 to the home position and in the process after driving the halogen lamp 5a until the actual start of exposure, the lid 31
Therefore, when the halogen lamp 5a starts up, the interlock switch 107 is cut off by opening the lid 31, and arcing caused by the large inrush current that occurs when the halogen lamp 5a starts up. Contact 10 of AC relay 103 due to discharge
This makes it possible to avoid the problem of melting and destruction of parts 2a and 102b.

In this embodiment, the specific position is the exposure start position, that is,
This is the reading start position. Therefore, a conventional document table control sensor can be used as the position detection means of the present invention.

〔Effect of the invention〕

As described above, according to the present invention, when it is recognized that the document table is not at the exposure start position based on the detection signal output from the position detection means, the switching means is opened, so that the light source from the power supply is Since we decided to cut off the power supply, we can ensure sufficient safety even when the lid is opened and various parts of the device can be contacted, and we also use a large-capacity contact mechanism that can withstand excessive overshoot current. Even without it, the contact mechanism will not be welded or destroyed, making it possible to have a low-cost contact mechanism and also to protect the contacts.

111...SS relay 119...Original platen exposure start position detection sensor, 121...CPU0

Claims (1)

[Claims] A document table that can be reciprocated with respect to the apparatus main body, a position detection means that detects whether the document table is at a predetermined specific position, a light source that irradiates light toward the document table, and the light source. a switching means that connects and disconnects power between the light source and the power source; a lid that is attached to the main body of the apparatus so as to be openable when the document table is not at a specific position; A contact mechanism is configured to open between the light source and the power source when the lid is opened, and a detection signal output from the position detection means indicates that the document table is not at a specific position. An image forming apparatus comprising: a control means for opening the switching means to cut off power supply from the power source to the light source when the image forming apparatus recognizes the light source.