JPS62296285A - Safety device for optical reader - Google Patents

Abstract

PURPOSE:To prevent an electric shock by opening a cover when a light source is replaced, permitting a cover switch to detect how the cover is opened, rendering a switching circuit to keep a light source drive circuit in a conduction cut state and blocking conduction to the connection part of the light source. CONSTITUTION:When a fluorescent lamp 24 is replaced, the cover 14 is pulled upward to open a window 14, and a connector 30 is removed. A screw 29 is loosened, and a sliding plate 27 is pulled out of the window 14 together with the fluorescent lamp 24. At that time the cover switch 36 is turned OFF because a locking piece 33 is separated from an actuator 35, and the output of a buffer 40 comes to a level L. Consequently, even if signal a level H is outputted from a step motor power source signal line 1, a step motor 23 is never driven. Even if a signal at a level H is outputted from a light source lighting control signal line 2, the fluorescent lamp 24 never lights up. Thus even if a person touches the terminal of the connector 30 in order to replace the fluorescent lamp 24, he never gets an electric shock.

Description

[Detailed description of the invention] 3. Detailed description of the invention Industrial applications The present invention relates to a safety device for an optical reading device.

2. Description of the Related Art Conventionally, there has been a system in which a document is placed on a document table of a case in which an optical reading section having a light source is built in, and the contents of the document are read while the document is illuminated by the light source. In this type of device, the light source is replaced relatively often. For this purpose, the case is provided with a window that can be opened and closed by a cover.

Problems to be Solved by the Invention The voltage for driving the light source is relatively high, and if you forget to turn off the power switch, there is a risk of electric shock.

Furthermore, even if the light source is replaced, there may be a disconnection, but since the disconnection of the light source cannot be confirmed unless a reading operation is performed, the disconnection may not be noticed until the next use.

The present invention has been made in view of these points, and an object of the present invention is to provide a safety device for an optical reading device that prevents electric shock accidents when replacing a light source.

Means for Solving the Problems: An optical reading section, which is provided with a light source facing the document table and is held reciprocatingly by a guide section, is provided inside a case in which a transparent document table is laid on one side, A light source is connected to a light source drive circuit, a window facing the light source returned to the home position is formed in the case, a cover is attached to the window so as to be openable and closable, and a cover switch having an interference part with the cover is attached to the window. A switching circuit is provided near the window and connected to the output side of the cover switch to switch the light source drive circuit between a energized state and a energized cutoff state.

Further, a timer is provided for outputting an energization signal for a certain period of time regardless of the operation of the reading start switch when transitioning from the energization cutoff state to the energization state based on the switching operation of the switching circuit, and this timer is connected to the light source drive circuit. .

Therefore, when replacing the light source, the cover is opened, but the switching circuit is switched by the operation of the cover switch in conjunction with the opening operation of the cover, and the light source drive circuit is maintained in the energized state, and the power is supplied to the connection part of the light source. cut off.

In addition, when the cover is opened and the light source is replaced, and then the cover is closed, the switching circuit is switched by the operation of the cover switch that is linked to the closing operation of the cover, and the light source is replaced while the timer outputs the energization signal. The light source is driven by the drive circuit, and the presence or absence of a break in the light source is automatically checked.

Example An embodiment of the present invention will be described based on the drawings.

FIG. 2 shows a case 1. On the top surface of this case 1, there are provided a transparent document table 3 on which a document 2 is placed, a scale 4 that presses around the document table 3, and operation keys 5.
A power switch 6 is provided on the side. Operation key 5
is equipped with a reading start key 7, a paper size selection key 8, a contrast adjustment knob 9, etc. Also, case 1
A case cover 11 having a handle 10 is attached to a binge part 12.
It is rotatably mounted. Furthermore, case 1
A window 14 that can be opened and closed by a cover 13 is formed on the back side of the unit (see FIG. 5).

Next, as shown in FIG. 3, an optical reading section 25 is provided inside the case 1. That is, the optical path cover 1
5 is slidably fitted to a guide shaft 16 which is a guide portion. A timing belt 17, which is partially fixed to the optical path cover 15, is wound around pulleys 18 located at both ends, and one pulley 18 is connected to a step motor 23 via gears 19, 20, 21, and 22. . Also, Hara 832
A socket 26 to which a straight tube fluorescent lamp 24, which is a light source facing the lamp, is connected is fixed to a sliding plate 27.

The sliding plate 27 has one end facing the cover 13 and is held by the optical path cover 15 so as to be slidable in a direction orthogonal to the moving direction of the optical path cover 15, and the end facing the cover 13 is secured by a screw. 29, it is fixed to a part of the optical path cover 15. Furthermore, the optical path cover 15 includes a fluorescent lamp 2.
A connector 30 is attached to connect the light source drive circuit 4 and a light source drive circuit to be described later. Furthermore, a PC board 28 to which a solid-state imaging device is connected is attached to the optical path cover 15.

In addition, as shown in FIGS. 4 and 5, the window 14 of case 1
A small hole 32 into which a projecting piece 31 formed on the cover 13 is inserted from above, and a locking claw 34 that engages with a locking piece 33 formed on the cover 13 so as to be elastically flexible are formed near the cover 13. has been done. Furthermore, a cover switch 36 having an actuator 35 which is an interference part for the locking piece 33 of the cover 13 is fixed inside the window 14 .

Next, FIG. 1 shows an electronic circuit. A CPU 38 connected to the host computer 37 is connected to the output side of a buffer 40 whose input side is connected to the cover switch 36 and to the VCC power supply via a pull-up resistor 39. In addition, the output side of buffer 4o and CPU 3
The output side of the NAND circuit 41 whose input side is connected to the step motor power supply signal line Φ1 from 8 is the transistor 4.
The emitter of this transistor 42 is connected to the Vdd power supply, and the collector is connected to the base of the step motor 2.
Connected to 3. This step motor 23 is connected to the CPU 38 via a step motor drive circuit 43 for each phase. In addition, the output side of buffer 4o and CPU 3
The output side of the AND circuit 44, which is a switching circuit whose input side is connected to the eight light source lighting control signal lines Φ2, is connected to the fluorescent lamp 24 via the light source drive circuit 45 and the connector 30. Furthermore, the CPU 38 includes an optical path cover 1.
A home position sensor 46 that detects the home position by contacting the home position sensor 5, a timer 47, and a power switch 6 are connected.

In such a configuration, when the power switch 6 is turned on, the locking piece 33 pushes the actuator 35 when the window 14 is closed by the cover 13, so the cover switch 36 is turned on and the output side of the buffer 40 goes to H level. becomes. Therefore, step motor power signal line Φ1
When an H level signal is output from the transistor 42
is turned on, and while the step motor drive circuit 43 is energized, the step motor 23 is driven, the timing belt 17 rotates, and the optical path cover 15 runs. During this time, when an H level signal is output from the light source lighting control signal line Φ2, the light source drive circuit 45 lights the fluorescent lamp 24. In this state, the contents of the document 2 are read. This reading operation is a well-known technique, so a description thereof will be omitted.

In addition, when replacing the fluorescent lamp 24, pull the cover 14 upward to open the window 14, remove the connector 30, and tighten the screw 2.
9 and pull out the sliding plate 27 together with the fluorescent lamp 24 from the window 14. At this time, the cover switch 36 is turned OFF because the locking piece 33 is separated from the actuator 35, and the output J of the buffer 40 becomes L level. Therefore, even if the step motor power supply signal line Φ1 outputs a signal at level I, the step motor 23 is not driven. Further, even if an H level signal is output from the light source lighting control signal line Φ2, the fluorescent lamp 24 is not lit. Therefore, there is no risk of electric shock even if the terminals of the connector 30 are touched when replacing the fluorescent lamp 24.

Next, the overall flow of operations will be explained with reference to the flowchart of FIG. When the reading start switch 7 is turned on with the power switch 6 turned on,
As a result of the above-described operation, the fluorescent lamp 24 is turned on and the step motor 23 is driven, so that the data on the document 2 is read and processed. The read data is output line by line to an externally connected device such as a personal computer. When the optical path cover 15 reaches a certain position, the step motor drive circuit 43 stops the step motor 23, and the light source drive circuit 45 turns off the fluorescent lamp 24.

Next, when the step motor drive circuit 43 reverses the step motor 23 and returns the optical path cover 15 to the home position, the home position sensor 46 is activated and the step motor 23 is rotated in reverse. The output from the tHTf signal line Φ1 is set to L level, and the step motor 23 is stopped. This operation continues by pressing the reading start switch 7 as long as the power switch 6 and cover switch 36 remain ON.
It is repeated by this.

When the cover 13 is opened when replacing the fluorescent lamp 24, the cover switch 35 is turned OFF as described above, the step motor 23 is stopped, and the light source drive circuit 45 is also maintained in the OFF state. Next, after replacing the fluorescent lamp 24, replace the cover 1.
3 is closed, the cover switch 36 is turned on, and the light source drive circuit 45 is activated based on the detection signal of this cover switch.
At the time of transition from the de-energized state to the energized state, the timer 47 is set regardless of the operation of the reading start switch 7, and the fluorescent lamp 24 is turned on until the time set in the timer 47 has elapsed.

That is, each time the cover 13 is opened and closed to replace the fluorescent lamp 24, the fluorescent lamp 24 is turned on for several seconds to automatically check for a disconnection.

Note that a sensor having a light emitting element and a light receiving element may be used as the cover switch. In this case, the space between the light emitting element and the light receiving element that is blocked by the cover 13 is
This is the part that interferes with the

Effects of the Invention Since the present invention is constructed as described above, the cover is opened when replacing the light source, and the cover switch detects the open state of the cover, and the switching circuit maintains the light source drive circuit in the energized state. , the power to the connection part of the light source can be cut off to prevent electric shock accidents, and each time the cover is opened and closed to replace the light source, the timer will turn on the power based on the switching operation of the switching circuit. The light source driving circuit drives the light source while the signal is being output, and has the advantage that it is possible to automatically check whether the light source is disconnected or not.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a block diagram, FIG. 2 is a perspective view showing a reduced appearance of the case,
FIG. 3 is a perspective view showing the optical reading section, FIG. 4 is a partial longitudinal side view showing the area around the window of the case, FIG. 5 is a partial exploded perspective view showing the area around the window of the case, and FIG. The figure is a flowchart.

Claims (1)

[Claims] 1. Inside a case with a transparent document table on one side,
an optical reading section provided with a light source facing the document table and held reciprocally in the guide section, the light source connected to a light source drive circuit, and a window facing the light source returned to the home position in the case; A cover is attached to the window so as to be openable and closable, a cover switch having an interference part with the cover is provided near the window, and the light source driving circuit is connected to the output side of the cover switch to be in a energized state. A safety device for an optical reading device, characterized in that it is provided with a switching circuit that switches between an energizing state and a de-energized state. 2. Inside the case, which has a transparent document table on one side,
an optical reading section provided with a light source facing the document table and held reciprocally in the guide section, the light source connected to a light source drive circuit, and a window facing the light source returned to the home position in the case; A cover is attached to the window so as to be openable and closable, a cover switch having an interference part with the cover is provided near the window, and the light source driving circuit is connected to the output side of the cover switch to be in a energized state. and a timer for outputting an energizing signal for a certain period of time regardless of the operation of the reading start switch when the switching circuit switches from the energizing cutoff state to the energized state based on the switching operation of the switching circuit. A safety device for an optical reading device, characterized in that the timer is connected to the light source drive circuit.