JPH0444514Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an image forming apparatus, and particularly to an image forming apparatus in which a part of the apparatus can be opened.

[Prior art and its problems]

In an image forming apparatus of the type in which a portion in which a rotating member is housed is opened to remove paper jammed therein, rotating rolls and the like must be stopped in order to ensure safety when opening the portion. Conventionally, a dedicated switch was provided that operated when the device was opened, and the rotating rolls and the like were stopped by a signal from the switch.

In this case, since a dedicated position is provided to detect the open state of the device, there are problems in that the structure is unreasonable, especially in small machines, the mechanism is complicated, and the cost is high. .

[Purpose of invention]

In view of the above-mentioned conventional drawbacks, the present invention has a simple and inexpensive structure by simultaneously detecting the presence of paper and the open state of the device using a paper discharge detection switch installed in the paper discharge section. An object of the present invention is to provide an image forming apparatus that can ensure safety when dealing with paper jams and the like when the apparatus is opened.

[Key points of the idea]

In order to achieve the above object, the present invention provides an image forming apparatus in which a part of the apparatus can be opened, and includes an actuator and a detection member for detecting displacement of the actuator in the paper path of the openable part, and the detection member includes:
When the trailing edge of the paper passes through the paper path, the actuator is displaced by a predetermined amount, and when the next paper reaches the leading edge, the actuator is displaced by the same amount as the predetermined displacement, thereby causing the actuator to move according to the paper interval. an output signal for a time of 1 and an output signal for the first time when the actuator, which opens a portion of the device from a closed position to an open position, is displaced by an amount different from the predetermined amount of displacement due to its own weight; an output signal of a shorter second time;
and a timer means set shorter than the time set and longer than the second time, the second time and the timer means are compared, and when the second time is shorter than the set time of the timer means, the device The apparatus is characterized in that it includes a discriminating means for discriminating whether the image forming apparatus is partially opened, and a prohibiting means for prohibiting an image forming operation when the partially opened state is opened.

[Example of idea]

An embodiment of the present invention will be described with reference to the drawings, taking a printer as an example.

FIG. 7 is a schematic configuration diagram showing an example of a printer device to which the present invention is applied.

The printer device 1 includes a recording section 3 that forms recorded information (image) on a drum-shaped photoreceptor 2, and a paper feeder that sequentially conveys paper 4 in synchronization with the recorded information formed on the photoreceptor 2. 5, and a conveyance section 6 that conveys the paper 4, reverses it, and discharges it to a predetermined position.

The recording unit 3 includes a charger 7 disposed above and close to the photoconductor 2 and uniformly charging the photoconductor 2;
A print head 8 records record information on the photoconductor 2 to form an electrostatic latent image, a developer 9 develops the electrostatic latent image formed on the photoconductor 2, and a print head 8 that records recorded information on the photoconductor 2 to form an electrostatic latent image. It is comprised of a transfer device 10 that transfers the image onto the paper 4, a cleaner 11 that removes residual toner on the photoreceptor 2 that was not transferred during the transfer process using the transfer device 10, and the like. In this embodiment, the print head 8 uses, for example, a liquid crystal light shutter in which a large number of microshutters are assembled in the main scanning direction, and electrostatic charges are applied to the photoreceptor 2 by light incident from a light source (not shown) through a light guide. Form a latent image.

The paper feed section 5 includes a cassette 12 that stores sheets 4 of a predetermined size in a stacked manner, a paper feed roller 13 that takes out and feeds the sheets 4 one by one from the top, and a guide for the conveyance direction of the sheets 4. a guide plate 14 that conveys the paper 4 along the guide plate 14;
5, and a pair of standby rolls 16 for conveying the paper 4 to the transfer device 10 in synchronization with the recorded information on the photoreceptor 2.

The conveyance section 6 transfers recorded information on the photoreceptor 2 to the transfer device 1.
A roll 17 that separates the paper 4 transferred at 0 from the photoreceptor 2, and a guide plate 18 that receives the paper 4.
, a fixing device 19 that fixes recorded information after transfer with heat and pressure, a plurality of guide plates 20, 20, 21a, 21b that guides the paper 4 upward, and these guide plates 20, 20, 21a, 21b. first conveyance rolls 22, 22 and second conveyance rolls 23a, 23b that convey the paper upward along the same direction, and paper discharge rolls 25a, 25b that discharge the paper to the discharge section 24 in a face-down state with the image facing downward. It consists of

FIG. 1 is a partially enlarged longitudinal cross-sectional view showing the main parts of the conveying section 6. As shown in FIG. A part of the conveyance section 6 is a paper discharge unit 26.
It has been made into a unit.

The paper discharge unit 26 includes a frame 27 and a second transport roll 23a attached to the frame 27.
, a paper ejection roll 25a, a guide plate 21a, an interrupter-type photo sensor 28 and an actuator 29 provided between the second transport roll 23a and the paper ejection roll 25a, and the like. It can be opened by rotating around the shaft 27a.

FIG. 1 shows a state in which the paper ejecting unit 26 is closed, and the second
The figure shows a state in which the paper discharge unit 26 is opened. In FIG. 1, the second transport roll 23a and the paper discharge roll 25a are arranged along a substantially vertical surface of the frame 27. As shown in FIG.

The guide plate 21a extends approximately vertically to the second transport roll 23.
a and the paper discharge roll 25a, and has a hole 30 near the paper discharge roll 25a.

The actuator 29 is located between the guide plate 21a and the frame 27, and has an arc-shaped tip with two rectangular protrusions A, C and grooves B, D arranged in parallel along the arc, and a groove formed at the bottom. It is rotatably supported by a shaft 27b provided on the frame 27 at the corner portion. The actuator 29 is
A protrusion E that protrudes toward the guide plate 21a is formed at the tip, and the protrusion E enters the hole 30 of the guide plate 21a and protrudes into the path of the paper.
A balance weight 29a is attached near the protrusion E, so that when the paper discharge unit 26 is in a closed state, the center of gravity is on the guide plate 21a side with respect to the shaft 27b. The actuator 29 is the paper discharge unit 26
When the is opened and rotated by a predetermined angle as described later, the protrusion E is rotated at the same time and comes out of the hole 30 of the guide plate 21a as shown in FIG. comes into contact with.

The photo sensor 28 is fixed to the side surface of the frame 27, and consists of a light emitting element and a light receiving element (not shown) provided opposite to each other on opposite side surfaces of the frame 27. In the circuit shown in FIG. 4, the light receiving element 28b emits light. This photo sensor outputs an H signal corresponding to voltage _V5 when it receives light from the element 28a, and outputs an L signal when it does not receive light. This photo sensor 28 is connected to the paper ejection unit 26.
When in the closed state, as shown in FIG. 1, the light is blocked by the protrusion A at the tip of the actuator 29,
Also, when the paper discharge unit 26 is in the open state, the second
As shown in the figure, it is provided at a position that matches the groove D.

3a to 3c are partially enlarged side views showing the operation of the actuator 29. FIGS.

FIG. 3a shows the state in which the paper discharge unit 26 is normally closed. At this time, the balance weight 29a
The line shown by a dashed dotted line connecting the axis 27b and the axis 27b is
Since it is on the right side of the perpendicular line indicated by the chain double-dashed line,
The actuator 29 is given a clockwise rotational force in the figure by a balance weight 29a. The photo sensor 28 is located at the protrusion A and is shielded from light by the protrusion A, so the fourth
In the circuit shown in the figure, an L signal is output.

FIG. 3b shows the state when the paper passes through the actuator 29 section. The protrusion E of the actuator 29 is pushed by a sheet (not shown) passing between the guide plates 21a, so that the groove B comes to the position of the photo sensor 28. At this time, the circuit shown in FIG. 4 outputs an H signal of voltage _V5 .

Figure 3c shows the paper discharge unit 2 as shown in Figure 2.
6 is opened. The actuator 29 rotates so that the tip of the protrusion A comes into contact with the inner surface of the frame 27, and the groove D comes to the position of the photo sensor 28. In the circuit shown in _FIG .
A signal is output.

When the sheet discharge unit 26 is opened at an angle of θ or more from the closed state shown in FIG. A pulse signal is generated.

5a to 5c are time charts showing the operations of the actuator 29 and the photo sensor 28. FIG.

When the paper passes through the actuator 29, an H signal is output as shown in Figure 5a.
The time T ₁ is when the paper is passing normally, and the time T ₂ is the interval between the next paper and the paper. For example length
When a sheet of 182 mm is conveyed at an interval of 50 mm and a conveyance speed of 50 mm/sec, T ₁ =3.64 seconds and T ₂ =1 second, and these T ₁ and T ₂ signals are used as jam detection signals.

When the paper discharge unit 26 is opened from the closed state while the paper is not passing through the actuator 29 part, the time _T0 for the groove B of the actuator 29 to pass the sensor 28 position is as shown in FIG. 5b. The H signal is output, the L signal is output during the time T when the protrusion C passes, and then the paper discharge unit 2
6 is open, an H signal is outputted by the groove D.

When the paper ejection unit 26 is opened from the closed state while the paper is passing through the actuator 29,
As shown in FIG. 5c, the L signal is outputted only for the time T when the protrusion C passes the actuator 29 at the position of the photo sensor 28, and then the H signal is outputted from the groove D while the paper discharge unit 26 is open.

The outputs during the times T ₀ and T mentioned above are both pulse signals that are generated when the actuator 29 rotates and have a very short period of time, for example, about 0.1 seconds or less. In this embodiment, the falling pulse and rising pulse of T are detected and used.

FIG. 6 is a flowchart showing an embodiment of the present invention.

Step when turning on the drive power of printer device 1
If the photo sensor 28 outputs an H signal in 1ST ₁ , the paper is in a jam state or the paper ejection unit 2
Since ST 6 is in the open state, the alarm lamp is lit in ST ₂ and printing is prohibited. Photo sensor 2 with ST ₁
8 is outputting an L signal, the falling edge detection ST ₃ of the pulse signal causes the set time to be 0.1, for example.
ST ₄ to start the timer for seconds. If the sensor 28 outputs an H signal before this timer times up, the rising edge detection ST ₅ immediately shuts off the drive power and stops driving at least the rotating parts exposed to the outside when the paper ejection unit 26 is opened, thereby ensuring safety. When the set time of the timer reaches ST ₆ and the H signal is not output, ST ₇ is in the state shown in FIG. 5a, and the paper is being conveyed normally, so the process returns to ST ₃ .

[Effect of idea]

According to the present invention, an image forming apparatus that can be partially opened is provided with a detection member that generates a first predetermined signal when paper passes, and when the paper is partially opened, the detection member generates the first predetermined signal. generates a different second predetermined signal, and in response to the second predetermined signal, the rotary member that is exposed to the outside due to the partial opening is stopped, so one sensor can detect the passing of the paper and the partial opening of the device. Since it can detect both, the structure is simple and inexpensive.

[Brief explanation of the drawing]

The drawings are all related to embodiments of the present invention, and FIG. 1 is a partially enlarged vertical sectional view showing the paper ejecting unit of the printer device in a closed state, and FIG. 2 shows the same state in which the paper ejecting unit is opened. FIGS. 3a to 3c are partially enlarged longitudinal sectional views showing the operation of the actuator and photo sensor as detection members, FIG. 4 is a partial circuit diagram including the photo sensor, and FIGS. 5 a to 5 FIG. 6 is a flowchart, and FIG. 7 is a schematic configuration diagram showing the entire printer apparatus. DESCRIPTION OF SYMBOLS 1... Printer device, 2... Photoreceptor, 3... Recording section, 4... Paper, 5... Paper feeding section, 6... Conveyance section, 7... Charger, 8... Print head, 9... ...Developer, 10...Transfer device, 11...Cleaner, 12
... Cassette, 13 ... Paper feed roller, 14 ... Guide plate, 15 ... Conveyance roll, 16 ... Standby roll pair, 17 ... Separation roll, 18 ... Guide plate, 1
9... Fixing device, 20, 21a, 21b... Guide plate, 22... First conveyance roll, 23a, 23b...
...Second transport roll, 24...Discharge section, 25a, 2
5b... Paper discharge roll, 26... Paper discharge unit, 2
7... Frame, 27a, 27b... Shaft, 28...
...Photo sensor, 28a...Light emitting element, 28b
... Light receiving element, 29 ... Actuator, 29a
...Balance weight, 30...Hole, A, C...
Protrusion, B, D...groove, E...protrusion.

Claims (1)

[Claims for Utility Model Registration] In an image forming apparatus in which a part of the apparatus can be opened, an actuator 29 is provided in the paper path 6 of the openable part.
and a detection member 28 that detects the displacement of the actuator 29, and the detection member 28 displaces the actuator 29 by a predetermined amount (protrusion A from groove B) when the rear end of the paper passes through the paper path 6. , by displacing the actuator 29 by the same amount as the predetermined displacement (from protrusion A to groove B) when the leading edge of the next sheet reaches, an output signal of the first time T2 corresponding to the sheet interval and the output signal of the device are generated. The actuator 29, which opens the part from the closed position to the open position, is outputted by performing a displacement (from groove B to groove D) different from the predetermined displacement (from groove B to protrusion A) due to its own weight. a timer means ST4, which is set to be shorter than the first time T2 and longer than the second time T;
The second time T and the timer means ST4 are compared, and the second time T is determined by the timer means ST4.
Discrimination means for determining that the device is partially open when the time is shorter than the time set in ST4 (ST5, ST7)
An image forming apparatus characterized by further comprising a prohibition means ST6 for prohibiting the image forming operation when the part is opened.