JPS63121860A - Original illuminating device - Google Patents

Abstract

PURPOSE:To preclude an electric shock accident due to contact with an exposed high voltage part by providing a means which detects the breakage of contact glass, a means which detects the opening/closing state of a protection cover, and a means which detects the potential of a capacitor. CONSTITUTION:When the contact glass 3 breaks after electric charging or when the protection cover 11 is opened, a relay 33 is on, so a relay 18 turns on while a switch 8 or 12 turns on, thereby generating a warning. A charging detection voltage V1 drops even when a control part 23 sends a reset signal 45, so the relay 33 is not reset above a reference voltage V0. Namely, the relay is not reset unless a main capacitor 23 is discharged sufficiently, and when the protection cover 11 is opened at this time, the relay 18 turns on to generate a warning. Even if a broken piece of the contact glass 3 is held between a fixed member 6 and an upper base member 7, the switch 8 operates securely. Consequently, an electric shock accident due to contact with the exposed high voltage part is precluded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a Franche lamp type document illumination device, and more specifically, it detects breakage of a contact glass or the open/closed state of a protective cover and generates an alarm. We will provide warnings such as displays. This invention relates to a document illumination device with improved safety.

(Prior Art) A Franche lamp type document illumination device in an electrophotographic apparatus has a rigger wire provided around the outer periphery of a flash lamp.

By applying a predetermined high voltage to this, the flash lamp is activated to light up. For this reason, the flannel lamp is surrounded by a cover to ensure safety.

On the other hand, when replacing or performing maintenance on the Franche lamp, the cover is opened and (and) breakage of the contact glass is detected and the power is automatically cut off to prevent electric shock. He was trying to avoid danger.

However, even if the power supply to the device is stopped, the main capacitor for the Franche lamp's light emission is installed inside the device, and the main capacitor is charged with high voltage, so the flash lamp cannot be replaced. When performing replacement processing by opening the main unit cover.

Alternatively, if the contact glass is damaged, there is a risk of electric shock due to contact with a high-voltage part within the device.

〔the purpose〕

The present invention was made in view of these drawbacks, and
The purpose is to provide a document illumination device that prevents electric shock accidents caused by opening the protective cover for lamp replacement or by touching a high-voltage part exposed due to breakage of the contact glass.

〔composition〕

To achieve this purpose, it detects when the charging voltage of the capacitor is higher than a given voltage, and when the contact glass is broken or/and the protective cover is open, and a warning such as a flaw alarm 2 is displayed. It is something.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 and 2 are explanatory diagrams showing the structure of a document illumination device used in an electrophotographic apparatus according to the present invention.

A Franche lamp 1 irradiates light onto the original 4, and a flash lamp 1 is fixed to a lower base member 9 below the flash lamp 1 to prevent the light from directly irradiating the original 4 by directing light toward the original 4. Around the flash lamp 1, a concentric reflector 5 is placed around the flash lamp 1, which reflects the light irradiated on the opposite side to the reflector 2 toward the reflector 2. is increasing.

The contact glass 3 on which the original 4 is placed is fixed to the upper base member 7 by a fixing member 6, and the lower part of the contact glass 3 is adjusted so as to be in constant contact with the lower surface of the contact glass 3, and the upper part A switch 8 fixed to the base member 7 with a bracket (not shown) or the like is provided to constantly detect damage to the contact glass 3.

In addition, for maintenance and inspection inside the Franche lamp 1 and other equipment, an opening 10 is provided between the upper base member 7 and the lower base member 9 that holds the reflector 2. 2 During normal operation, the opening 10 is covered with a protective cover. An open/close detection switch 12 fixed to the lower base member 9 constantly detects whether the protective cover 11 is open or closed.

Furthermore, an outer cover 13 is provided outside the protective cover 11 and the upper base member 7 to protect the main body of the apparatus.

In addition, as shown in FIG. 2, the two sides of the contact glass 3 adjacent to the upper base member 7 are fixed by fixing members 6, and the fixing members 6 are used to indicate the size and placement position of the original 4. printed. The switch 8 is disposed below the free end corner portion 14 of the contact glass 3 to detect breakage of the contact glass 3.

The Franche lamp 1 is held by a lamp holder 16 and fixed to a lower base member 9.

Further, a trigger wire 17, which is a trigger means for energizing the flash lamp 1 to emit light, is wrapped around the flash lamp 1, and the trigger wire 17 draws power from both ends of the flash lamp 1. Connected to a trigger unit (not shown).

Furthermore, a nickel wire is used for the trigger wire 17, and the metal part is exposed.

When the flash lamp 1 is turned on, high pressure is applied to the trigger wire 17, which is very dangerous, so the protective cover 11 is attached.

FIG. 3 is an explanatory diagram of the control circuit in the present invention.

A power supply 20 that supplies driving energy inside the device, and a relay 18 (normally closed contact 1) that switches the supply of the power supply 20 from the charging circuit to the warning circuit or vice versa.
9. , 19. and 39a.

39), a rectifier circuit 50, and the rectifier circuit 50
A capacitor 51 that removes pulsations from the voltage waveform obtained by
a rectifying and smoothing circuit 21 consisting of a rectifying and smoothing circuit 21, and a DC-1) as a power conversion circuit that converts DC input voltage to an arbitrary DC voltage.
A C converter 22 is provided.

The DC-DC converter 22 includes a resistor 30 that generates a charge detection voltage (1), a main capacitor 24, a Franche lamp 1 that is made to emit light by the main capacitor 24, and a Franche lamp 1 that is activated by a trigger signal from a control unit 23, which will be described later.
A trigger circuit 25 for energizing a trigger wire 17 provided around the trigger wire 17 is connected thereto.

Further, a coil 52 is installed between the main capacitor 24 and the flash lamp 1 in order to control the discharge time of the flash lamp 1.

Next, a transformer 26 that transforms the power from the power supply 20 as a charging voltage detection circuit. and a rectifying and smoothing circuit 27 similar to the above.
, 3-terminal regulator rake 281, and reference voltage V. 29. , 29, a diode 34 for maintaining the charging detection voltage V1 at the peak voltage, and a capacitor 35 are provided.

Also, the reference voltage ■. A comparator 31 for comparing the voltage and charge detection voltage (1), a transistor 32 that turns on the ONL and relay 33 by the operation of the comparator 31, and a transistor 32 that turns on the 1-rigger signal from the control section 23.
A normally open contact 38 is arranged between the photocoupler 36 that operates, the transistor 37 that operates when the photocoupler 36 is turned on, the switch 8 and the switch 12 that are connected in parallel, and the relay 18 and the switch 8 and the switch 12. has been done.

Next, as a warning circuit, a transformer 26 that transforms the power from the relay 18. A rectifying and smoothing circuit 40 similar to the above, a three-terminal regulator 28°, and further connected to the rectifying and smoothing circuit 40 are a buzzer 41 that issues an alarm and an indicator lamp 42 that indicates "danger" and "caution".

The operation of the above configuration will be explained using the time chart of FIG.

Normally, switches 8 and 12 are OFF when the contact glass is not damaged and the protective cover is not open.
It is in F state.

Therefore, the relay 18 is also turned off. Normally closed contact 19 of relay 18. , 19b, power is co-supplied from the power supply 20 to the DC-DC converter 22 via the rectification and smoothing circuit 21.

During copying operation, the control unit 23 connects the DC-DC converter 22.
The main capacitor 24 is charged by the charging signal for
Thereafter, the trigger circuit 25 is activated by a trigger signal from the control section 23.

Discharge is performed using the trigger wire 17.

Flash lamp 1 emits light.

On the other hand, for 3 charging voltage detection circuits, transformer 26. Direct current is supplied through the three-terminal regulator 283. Furthermore, resistors 29a, 29. By the reference voltage■. is created and the main capacitor 24 is charged, the resistor 30
A charge detection voltage V is created by

The reference voltage V is determined by the comparator 31. and the charge detection voltage V1 are compared, and a reference voltage (■) is obtained. When the charge detection voltage V1 exceeds the voltage V1, the output becomes High, and the transistor 3
2, ONL relay 33 operates.

In this case, the charge detection voltage V is maintained at the peak voltage by the diode 34 and the capacitor 35.

The photocoupler 36 is activated by a trigger signal from the control unit 23.
is ONL, and as a result, the transistor 37 is activated, the capacitor 35 is discharged, and the peak hold is released. Due to this release, the output of the comparator 31 becomes Low, and as a result, the transistor 32 is turned off and the relay 33 is released.

Therefore, when the flash lamp is turned on, the relay 33 repeats opening and closing operations. Further, when the normally open contacts 38 of the relay 33 are both turned off, the relay 18 does not operate even if the normally open contacts 38 are turned on or off.

Next, when the contact glass 1 is damaged or (and) the protective cover is open, a charging signal is generated due to a malfunction or noise to the control unit 23, and the main capacitor 24 is charged, and the charging detection voltage 1
When the voltage becomes higher than the reference voltage v0, the relay 33 is activated. At this time, switch 8 or (and) switch 12 is O.
Since it is N, the normally open contact 38 of the relay 33 is closed, so the relay 18 is operated.

the result.

Normally closed contact 19 of relay 18. , 19b is released, and the supply of power to the charging circuit is stopped.

On the contrary, the normally closed contact of relay 18 is 398.39
b is closed, and as a result, power is supplied to the transformer 26, the rectifier smoothing circuit 40 and the three-terminal regulator 28.
The buzzer 412 and display lamp 42 are turned on via b: A warning is given to the operator and the like.

If the contact glass 1 is damaged or/and the protective cover is opened while the main capacitor 24 is being charged, the normally open contacts 38 of the relay 33 are closed, and the switch 8 or (and) the switch 12 is also closed.
Since it is N, the relay 18 operates in the same way, and as a result, the normally closed contact 19m+1 of the relay 18
Since 9b is released, the supply of power to the charging circuit is stopped.

On the contrary, the normally closed contacts 39, 39 of the relay 18
b is closed, and as a result, power is supplied to the transformer 26, the rectifier smoothing circuit 40 and the three-terminal regulator 28.
The buzzer 419 and display lamp 42 are turned on via b to issue a warning to the operator and the like.

When the buzzer 411 indicator lamp 42 is turned on.

Since the main capacitor 24 self-discharges, the warning can be stopped by outputting a release signal (pulse signal) from the control section 23 after a sufficient period of time has elapsed for the discharge.

Further, in order to ensure reliable operation of the charging voltage detection circuit and the warning circuit so that they will not stop working when the main switch is turned off, it is also good to install a separate power source (for example, a lithium battery).

The part in FIG. 4(I) means the operation of each part in the normal copy mode.

That is, charging is started by a charging signal, and the flash lamp 1 emits and discharges light by a trigger signal. relay 33
is the charging detection voltage V, and is the reference voltage V. O when it gets higher
It is turned off by a trigger signal from the NL control section 23.

The part (11) in FIG. 4 shows that even if the switch 8.12 is turned on during non-charging, the relay 18 does not operate and the warning circuit does not operate.

FIG. 4 (I [The part in parentheses means the operation of each part when charging is started when the contact glass 3 is broken or/and the protective cover 11 is opened.

That is, after the start of charging, when the reference voltage is reached, the relays 33 and 18 are turned on. When switch 8 or (and) switch 12 is opened, relay 18 is turned off and the warning is canceled, but relay 33 is not turned off and remains in a hold state.

However, since the charging operation is stopped when the relay 18 is turned on, the actual charging detection voltage decreases as the main capacitor 23 naturally discharges, as shown by the two-dot chain line 43. and.

When the charge detection voltage is checked again by the release signal 44 from the control unit 23, the charge detection voltage ■1 becomes the reference voltage ■
. Since it is now lower, the relay 33 will be released at that time.

The part in FIG. 4 (rV) means the operation of each part when the contact glass 3 is damaged or (and) the protective cover 11 is opened after charging.

Since the relay 33 is turned on, the relay 18 is turned on at the same time as the switch 8 or (and) the switch 12 is turned on, and a warning is issued.

Even if the release signal 45 from the control unit 23 is issued, the actual charging detection voltage (■1) decreases as shown in 46, so that the reference voltage (■). In the above cases, the relay 33 is not released. Therefore, even if the release signal 45 is issued, the relay 33 will not be released unless the main capacitor 23 is sufficiently discharged, and if the protective cover 11 etc. is opened at this time, the relay 18 will ONI and issue a warning. .

Other 2 In this embodiment, since the switch 8 is disposed below a part of the free end corner of the contact glass 3, when the contact glass 3 is broken, the fragments are transferred to the fixing member 6.
This is because even if the fragments of the free end portion 14 remain sandwiched between the upper heath members 7, they are not held down.

The switch 8 will surely operate.

If a piece of the contact glass 3 remains with the switch 8 pressed down (for example, broken line 15 in Figure 2), it will generally not break because the switch 8 is placed on the flash lamp 1 side. Since it is rare for an operator to insert his/her hand into the cross section and touch the lamp part, it is extremely important from a safety standpoint to place the switch 8 on the free end side 14 of the contact glass 3 as described above. It is valid.

〔effect〕

As explained above, according to the document illumination device according to the present invention, it is possible to detect when the charging voltage of the capacitor is higher than the arbitrary voltage, and when the contact glass is broken or the protective cover is open. Since a warning such as a low voltage alarm 1 is displayed, it is possible to prevent an electric shock accident caused by opening the protective cover for lamp replacement or by touching a high voltage part exposed due to a broken contact glass.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional explanatory diagram of a document illuminating device according to the present invention, FIG. 2 is a partially cutaway perspective explanatory diagram of the document illuminating device according to the present invention, and FIG. 3 is an operating circuit of the document illuminating device according to the present invention. FIG. 4 is an explanatory diagram, and FIG. 4 is a time chart showing the operation of each part of the document illumination device according to the present invention. Explanation of symbols ■...Franche lamp 3...Contact glass 4...Original f height 8.12...
Switch 17...Trigger wire 18...Relay 23...
・Control unit 24 ・・Main capacitor 25 ・・Trigger circuit

Claims (2)

[Claims] (1) In a document illumination device that irradiates a document with light emitted from a flash lamp having a trigger wire for activation and exposes a photoreceptor with the reflected light, a glass detection device detects breakage of the contact glass on which the document is placed. a cover detection means for detecting an open/closed state of a protective cover that protects the lamp; and a voltage detection means for detecting a potential of a capacitor for causing the lamp to emit light, and a signal input from the voltage detection means; Provided that the glass sensing means or (and)
A document illumination device characterized in that warning means such as an alarm and a display are activated based on a signal from the cover detection means. (2) The document illumination device according to claim 1, wherein the warning means is activated and stops power supply to the capacitor.