JPH04315141A - Safety device for contact glass - Google Patents

Abstract

PURPOSE:To obtain a safety device for a contact glass which gives a warning when the contact glass is broken or secures safety when an operator inserts a hand below the contact glass thereafter. CONSTITUTION:A detecting means 6 for detecting the broken state of a contact glass 2 when it is broken is provided, and a control part drives a display part 8 for warning in the case of judging according to a signal from the means 6 that the contact glass is broken.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for contact glass, and more particularly to the structure of a device that can warn of broken contact glass.

0002

BACKGROUND OF THE INVENTION As is well known, in image forming apparatuses such as copying machines, a copy original is set on a document table, a so-called contact glass, and then exposed to light.

[0003].

[Problem to be Solved by the Invention] By the way, this contact glass is vulnerable to shocks due to its material, but there are not many instructions on how to handle it in the event that it is damaged, so be careful when handling it. is the current situation. For this reason, measures have been taken to make the contact glass itself more rigid, such as using strong glass, but since contact glass with this type of structure is expensive, it is difficult to incorporate it into a copying machine. There was a risk that the cost would be high. Moreover, if it is damaged, especially if it cracks, it is dangerous for the user, and even if it breaks, it is not completely destroyed, so if you place the original on it without being aware of it, it is dangerous. There is also a risk of unexpected injury.

SUMMARY OF THE INVENTION In view of the above-mentioned problems with conventional contact glass, an object of the present invention is to provide a safety device that can warn in the event of breakage.

[0005] Another object of the present invention is to provide a safety device that can automatically stop energizing the parts located at the bottom of the contact glass in the event of breakage, thereby preventing the danger of touching those parts. It is in.

[0006]

[Means for Solving the Problems] In order to achieve this object, the present invention includes a reflective sensor disposed on the back side of a contact glass, a reflective sensor connected to the input side, and a warning signal on the output side. and a control section to which a display section is connected, and the control section determines that the contact glass is broken when no reflected light from the contact glass is incident, and outputs a signal to light up a warning display section. There is.

[0007] The present invention also provides a contact glass whose back surface is electrically conductive, and a conductive portion on the back surface of the contact glass that is provided at a plurality of locations to form a part of a closed circuit. The electrodes constituting the contact glass and the electrodes located as part of the closed loop circuit are connected to the input side, respectively, and the output side is connected to the power source for the electrical system including the illumination light source for the contact glass. a control unit connected to a power relay placed in the wiring leading to the contact glass; The feature is that the energization path to the power supply is cut off through the power supply.

Furthermore, the present invention provides a detection element arranged on the back side of the contact glass for detecting that the glass is broken, and the above-mentioned detection element is connected, and a signal from the detection element detects that the contact glass is broken. It is characterized by comprising a control section that outputs a signal when a determination is made, and a warning display section that is activated when a signal from the control section is output.

The present invention is characterized in that a plurality of sensing elements are provided on the back surface of the contact glass.

The present invention also provides a power relay that cuts off power to the electrical system of the optical device when the control section determines that the contact glass is broken based on a signal from the detection element.
It is characterized by being connected to

[0011]

[Operation] According to the present invention, a warning can be issued when the control section determines that the contact glass is broken.

Further, according to the present invention, when it is determined that the contact glass is broken, power to the electrical system of the optical meter is cut off to ensure safety in the event that the user touches the electrical system. be able to.

[0013]

[Embodiment] Details of an embodiment of the present invention will be explained below with reference to FIGS. 1 to 11.

FIG. 1 shows a schematic configuration of an exposure optical system 1 equipped with a contact glass, and this exposure optical system 1 has a contact glass 2 fixed in an opening formed on the top surface of the unit 1A. Below the contact glass 2, there is a lamp 3 which is an illumination light source, and a mirror for deflecting the optical path.
4 and an imaging lens 5 are arranged.

Below the contact glass 2 mentioned above,
In addition to the optical components described above, a reflective sensor 6 for detecting the presence of the contact glass 2 is arranged. That is, this reflective sensor 6 uses, for example, an ultrasonic sensor so as to be able to detect the presence of contact glass, which is a transparent body, and is equipped with a sound wave output port and a sound wave input port, as shown in FIG. As shown in FIG. 3(A), the case where the contact glass 2 is not broken and exhibits a uniform plane can be detected by detecting the reflection of the sound wave from the output port toward the input port. , the case where the contact glass 2 is broken and not on a uniform plane is detected by the fact that the sound waves from the exit port are not reflected toward the entrance port.

On the other hand, the above-mentioned reflective sensor 6 is connected to the input side of a control section 7, which will be described later, as shown in FIG. 4, and is configured to detect the state of the contact glass 2 and output a signal. . That is, although the details are not shown, the main part of the control section 7 is composed of a microcomputer 2, and a display section 8 equipped with an indicator lamp is connected to the output side. The control unit 7 described above controls the lighting display of the display unit based on the signal from the reflective sensor 6. Specifically, the control unit 7 controls the lighting display of the display unit based on the signal from the reflective sensor 6. The lamp on the display section 8 is turned on when there is no reflection of the sound wave.

Since the present embodiment has the above-described configuration, in the state shown in FIG. 3A, that is, when the contact glass 2 is not broken, the reflection of the sound wave to the entrance of the reflective sensor 6 is prevented. Therefore, the control section 7 does not turn on the lamp on the display section 8. On the other hand, as shown in FIG. 3(B), when the contact glass 2 is broken, the sound waves from the contact glass 2 do not reach the entrance of the reflective sensor 6, so a signal indicating this state is output to the control unit 7. do. Based on this signal, the control section 7 determines that the contact glass 2 is broken, and lights up the lamp on the display section 8, or displays a message indicating that the contact glass is abnormal.

Next, a second embodiment of the present invention will be described with reference to FIGS. 5 and 6.

FIG. 5 shows the structure of an exposure optical system 10 having a contact glass according to a second embodiment. The opening is equipped with a contact glass 11, and below the contact glass 11, an illumination light source lamp 12, a lamp terminal harness cover 13,
A flexible harness 15 that constitutes a power supply line to the document detection sensor (APS) 14 and the lamp 12
are placed respectively.

On the back surface of the contact glass 11 described above, as shown in FIG. 2, the area indicated by diagonal lines is a non-conductive part, and this non-conductive part constitutes a triangular conductive part. Electrodes 11A, 11B, 11C, and 11D are provided at the longitudinal center of each side of this conductive section, and these electrodes are connected to the input section of the control section 16, which will be described later, via lead wires. It is connected. Each of the above-mentioned electrodes constitutes a part of a closed circuit together with a control section, which will be described later, via the conductive section of the contact glass 11.

On the other hand, the above-mentioned control section 16 is equipped with a microcomputer as a main part, as shown in FIG.
1D is connected, and a power relay 17 is connected to the output side.
An optical system control unit 18 that controls lighting of the document detection sensor (APS) 14 and a light source is connected to the optical system control unit 18, and a power supply drive unit 20 connected to a power source 19 is connected to the optical system control unit 18 via a lead wire. connected. In each lead wire mentioned above,
A relay terminal 17A is provided to perform on/off setting by the power relay 17, and when the power relay 17 is turned off, the contact between the terminals is opened and the power source configured by the lead wire is Supply lines are now cut off.

The above-mentioned control unit 16 is configured to perform on/off control of the power relay 17 depending on the state of energization between the electrodes, and specifically, when it is determined that the energization between the electrodes has been cut off. In this case, the power relay 17 is set to the OFF state to open the contacts between the terminals in each lead wire, thereby cutting off the power supply line.

Since the present embodiment has the above-described configuration, when the contact glass 11 is not broken, the conductive part is not damaged, and current from the power source flows through each electrode.
Using this current as a signal, the control unit 16 connects the power relay 1 to close the contact of the relay terminal 17A in each lead wire.
Set 7 postures. Therefore, in this state, the functions of the optical system and document detection are performed.

On the other hand, if the contact glass 11 is broken, the current flow in the conductive portion is cut off, so that no current flows through the electrodes, and this information is input to the control section 16. Therefore, the control unit 16 determines that the current flow between the electrodes is interrupted and sets the power relay to the off state. When power relay 17 is turned off, the relay in the lead wire
The contact at the terminal is opened, the power line is cut off, and the optical system and document detection functions are interrupted. In this state, even if a user's hand enters the optical system and touches each electrical system, for example to replace or remove the contact glass 11, the risk of electric shock can be avoided. .

Next, a third embodiment of the present invention will be described with reference to FIGS. 7 to 11.

FIG. 7 shows the structure of an exposure optical system 21 having a contact glass according to a third embodiment, and in the same figure, the exposure optical system 21 is located on the upper surface of the unit as in the case shown in FIG. A contact glass 22 is fixed to the opening, and below the contact glass 22, an illumination light source lamp 23, an optical path deflection mirror 24, and an imaging lens 25 are arranged.

In addition to the optical components described above, a detection element 26 for detecting the presence of the contact glass 2 is arranged below the contact glass 22 described above. That is, the detection elements 26 are, for example, microswitches equipped with actuators that come into contact with the contact glass 22, and are arranged at both ends of the diagonal line of the contact glass 22, as shown in FIG. As shown in FIG. 9(A), this sensing element 26 is connected to the contact glass 2.
If the contact glass 22 is not broken and has a uniform plane, the actuator contacts it and closes the contact, and as shown in FIG. 9(B), the contact glass 22 is broken and does not form a uniform plane. At some point, the actuator protrudes and the contacts are opened.

On the other hand, the above-mentioned detection element 26 is connected to the input side of a control section 27, which will be described later, as shown in FIG. 10, and outputs a signal detecting the state of the contact glass 22.

That is, the main part of the control section 27 is constituted by a microcomputer, although its details are not shown, and a display section 8 equipped with an indicator lamp is connected to the output side. In the control section 27 described above, the detection element 26
The lighting display on the display unit is controlled by the signal from the display unit 28. Specifically, when the contact in the detection element 26 is opened, a lamp or a message on the display unit 28 is turned on. There is.

Since this embodiment has the above-described configuration, in the state shown in FIG. 9A, that is, when the contact glass 22 is not broken, the actuator of the sensing element 26 is pressed. Since the contact is closed, the control section 7 does not turn on the lamp on the display section 28. On the other hand, as shown in FIG. 9(B), when the contact glass 22 is broken, the actuator of the detection element 26 protrudes by its own habit to open the contact, and the signal is input to the control unit 27. be done. Then, in the control section 27,
Based on this signal, it is determined that the contact glass 22 is broken, and a lamp on the display section 28 is turned on, or a message indicating that the contact glass is abnormal is displayed.

Further, FIG. 11 shows a configuration for cutting off power from the power supply to the electrical system of the optical system when the contact glass 22 is broken in the control section 27 described above. The above-mentioned detection element 26 is connected to its input side, and the power relay 2 is connected to its output side.
8. The document detection sensor (APS) 29 and the optical system control section 30 that controls the lighting of the light source.
In this case, the power supply drive section 32 connected to the power supply 31 is connected to the power supply 31.
connected via a wire.

[0032] In each of the above-mentioned lead wires, there is a power relay.
Relay terminal 28A for on/off setting by 28
is provided, and when the power relay 28 is turned off, the contact between the terminals is opened and the power supply line constituted by the lead wire is cut off.

The above-mentioned control unit 27 is configured to perform on/off control of the power relay 28 based on the signal from the detection element 26, and specifically, determines that the current flow between the electrodes has been cut off. In this case, the power relay 28 is set to the OFF state to open the contacts between the relay terminals 28A in each lead wire, thereby cutting off the power supply line.

Since the present embodiment has the above-described configuration, if the contact glass 22 is not broken, the detection element 26 outputs a signal indicating that the contact is closed. , relay terminal 28A in each lead wire
The position of the power relay 28 is set so as to close the contacts. Therefore, in this state, the functions of the optical system and document detection are performed.

On the other hand, if the contact glass 2 is broken, the contacts in the detection element 26 are opened and the current is cut off, so that the current flow through the electrodes is stopped, and this is input to the control section 16. Ru. Therefore, the control unit 27 determines that the contact glass 22 is broken and sets the power relay to the OFF state. When the power relay 28 is turned off, the contact at the relay terminal 28A in the lead wire is opened, the power supply line is cut off, and the optical system and document detection functions are interrupted. In this state, even if a user's hand enters the optical system and touches the electrical system, for example to replace or remove the contact glass 22, the risk of electric shock can be avoided. .

[0036]

[Effects of the Invention] As described above, according to the present invention, the state of the contact glass, that is, the result of detecting whether it is broken or not, can be used to display a warning or to cut off power to the electrical system in the optical system. This allows the user to determine if there is an abnormality in the contact glass before use.
This makes it possible to avoid danger, and also ensures safety in the event that electrical parts placed below the contact glass are touched when replacing the contact glass.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing the arrangement of an exposure optical system to which a contact glass safety device according to a first embodiment of the present invention is applied.

FIG. 2 is a perspective view showing a part of the configuration of the safety device shown in FIG. 1;

FIG. 3 is a model diagram for explaining the operation of a part of the safety device shown in FIG. 2;

FIG. 4 is a block diagram for explaining the schematic configuration of a control section of the safety device according to the first embodiment of the present invention.

FIG. 5 is a schematic configuration diagram showing the arrangement of an exposure optical system to which a contact glass safety device according to a second embodiment of the present invention is applied.

FIG. 6 is a wiring diagram showing the main part configuration of a safety device according to a second embodiment of the present invention.

FIG. 7 is a schematic configuration diagram showing the arrangement of an exposure optical system to which a safety device according to a third embodiment of the present invention is applied.

8 is a perspective view showing a part of the configuration of the safety device shown in FIG. 7. FIG.

9 is a model diagram for explaining the operation of a part of the safety device shown in FIG. 8. FIG.

FIG. 10 is a block diagram for explaining the main part configuration of a safety device according to a third embodiment of the present invention.

11 is a wiring diagram for explaining a modification of the main part configuration shown in FIG. 10. FIG.

[Explanation of symbols]

Claims (5)

[Claims] 1. A reflective sensor disposed on the back surface of a contact glass, and a control section connected to the input side of the reflective sensor and a warning display section connected to the output side, the control section comprising: a reflective sensor disposed on the back surface of a contact glass; A safety device for contact glass, characterized in that the part determines that the contact glass is broken when no reflected light from the contact glass is incident, and outputs a signal to light up a warning display part. 2. A contact glass whose back surface is electrically conductive, and a conductive section provided at a plurality of locations on the back surface of the contact glass, forming part of a closed circuit. The electrode located in a part of the closed loop circuit is connected to the input side, and the output side is placed in the wiring leading to the electrical system including the illumination light source for the contact glass. power relay
and a control unit to which the contact glass is broken, and the control unit is configured to interrupt the energization path to the power source via the power relay when the closed circuit is interrupted when the contact glass is broken. A contact glass safety device featuring: Claim 3: When the contact glass is determined to be broken based on a signal from the detection element when the detection element is connected to a detection element arranged on the back side of the contact glass and detects that the glass is broken. A contact glass safety device comprising a control section that outputs a signal from the control section, and a warning display section that is activated when the signal from the control section is output. 4. The contact glass safety device according to claim 3, wherein a plurality of sensing elements are provided on the back surface of the contact glass. 5. The safety device according to claim 3, wherein the control unit connects a power relay that cuts off power to the electrical system of the optical device when it is determined that the contact glass is broken based on a signal from the detection element. Contact glass safety device.