JP6796262B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus.

A document transporting device generates a sound signal corresponding to the sound generated while the document is being transported, generates a signal that peak-holds the analog sound signal as a correction signal, and has a jam occurred based on the correction signal? Whether or not it is determined (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-219476

However, when jam is detected by the correction signal obtained by peak-holding the sound signal as described above, the jam is detected based on the amplitude of the sound signal, that is, the loudness of the detected sound. False detection of jam occurs when the noise is large or when the transport noise of the printing paper is temporarily loud.

The present invention has been made in view of the above problems, and an object of the present invention is to obtain an image forming apparatus that suppresses false detection of jam.

The image forming apparatus according to the present invention includes a transport device for transporting a document or printing paper, a microphone that collects sounds generated by the transport device and outputs a sound signal corresponding to the collected sounds, and (a). A sample hold signal of the sound signal is generated and attenuated by a predetermined time constant, (b) the timing when the level of the sound signal exceeds a predetermined threshold is detected as a trigger timing, and (c) the detected trigger timing It is provided with a jam detection unit that accumulates the fluctuation range according to the level of the sample hold signal to generate a detection signal, and (d) detects the occurrence of jam based on the detection signal. The predetermined time constant is set so that the level of the detection signal increases by accumulating the fluctuation width according to the level of the sample hold signal each time the trigger timing is detected.

According to the present invention, an image forming apparatus that suppresses false detection of jam can be obtained.

The above or other object, feature and superiority of the present invention will be further clarified from the following detailed description with the accompanying drawings.

FIG. 1 is a block diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating the sound signal obtained in FIG. FIG. 3 is a diagram illustrating a detection signal based on the jam generation sound. FIG. 4 is a diagram illustrating a detection signal based on a low frequency environmental sound.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention. The image forming apparatus shown in FIG. 1 is a printer, a scanner, a copier, a facsimile machine, a multifunction device, or the like, which includes a conveying device 1 for conveying a document or printing paper. That is, the transport device 1 is a document transport system such as an automatic document feeder or a printing paper transport system (not shown).

Further, the image forming apparatus shown in FIG. 1 includes a microphone 2, a controller 3, a printing apparatus 4, and an image reading apparatus 5.

The microphone 2 collects the sound generated by the transport device 1 and outputs a sound signal corresponding to the collected sound.

The controller 3 controls internal devices such as a printing device 4, an image reading device 5, and a communication device (not shown) together with the transport device 1. The controller 3 incorporates a computer that executes a program, an ASIC (Application Specific Integrated Circuit), and the like, and operates as a processing unit by the computer, the ASIC, and the like. The controller 3 supplies image data to the printing device 4, controls the printing device 4 to print an image based on the image data, and controls the image reading device 5 to read the original image. To acquire the image data of the original image. Further, the controller 3 operates as a jam detection unit 11. The printing device 4 prints an image based on the image data on the above-mentioned printing paper by a predetermined method such as an electrophotographic method or an inkjet method. Further, the image reading device 5 optically reads the original image from the above-mentioned original and generates image data of the original image. That is, the transport device 1 transports the printing paper to the printing device 4 and the document to the image reading device 5.

The jam detection unit 11 (a) generates a sample hold signal of the above-mentioned sound signal and attenuates it with a predetermined time constant, and (b) detects when the level of the sound signal exceeds a predetermined threshold value as a trigger timing. , (C) Accumulate the fluctuation range according to the level of the sample hold signal at the detected trigger timing to generate a detection signal, and (d) detect the occurrence of jam based on the detection signal.

In this embodiment, the jam detection unit 11 generates a detection signal by accumulating the difference (or the value obtained by multiplying the difference by a constant) between the above-mentioned threshold value and the level of the sample hold signal at the detected trigger timing. .. That is, the above-mentioned fluctuation range is proportional to this difference.

FIG. 2 is a diagram illustrating the sound signal obtained in FIG. FIG. 3 is a diagram illustrating a detection signal based on the jam generation sound. In FIG. 2, the sound signal for explanation is a triangular wave. For example, a sample hold signal as shown in FIG. 3 is generated from the sound signal shown in FIG. Then, as shown in FIG. 3, the fluctuation range according to the level of the sample hold signal at the trigger timing Ttr (in FIG. 3, the difference dV between the above-mentioned threshold value Vtr and the level of the sample hold signal) is added to the detection signal. .. That is, the level of the detection signal is set to zero at the start of the transfer operation of the transfer device 1, and each time the trigger timing Ttr is detected, the level of the detection signal increases by the above-mentioned fluctuation range.

For example, the jam detection unit 11 determines that a jam has occurred when the level of the detection signal exceeds a predetermined threshold value (a threshold value different from the threshold value of the trigger timing).

An amplifier, an A / D converter, or the like is provided between the microphone 2 and the controller 3 as needed.

Further, the above-mentioned "predetermined threshold value" for the trigger timing may be a ground level or a level different from the ground level. When the "predetermined threshold" is set to a level different from the ground level, minute fluctuations in the sound signal are ignored.

Further, the jam detection unit 11 may perform time averaging processing on the detection signal with a low-pass filter or the like, and detect the occurrence of jam based on the detection signal after the time averaging processing. As a result, the detection signal is attenuated while the trigger timing Ttr is not detected. Therefore, for low-frequency environmental sounds, since the number of times the trigger timing Ttr is generated is small, the level of the detection signal is unlikely to increase, and erroneous detection of jam is further suppressed.

Next, the operation of the image forming apparatus will be described.

When printing or scanning an image, the transport device 1 transports printing paper or a document to be scanned.

While the transport device 1 is transporting the printing paper or the original, the jam detection unit 11 continuously acquires the sound signal from the microphone 2 and generates a detection signal from the sound signal as described above, and the generated detection. Determine if a jam has occurred based on the signal level.

When the jam detection unit 11 determines that a jam has occurred, the jam detection unit 11 stops the operation of the transport device 1 and displays a message indicating that the jam has occurred on an operation panel or the like (not shown).

As described above, according to the above embodiment, the transport device 1 transports the document or the printing paper, and the microphone 2 collects the sound generated by the transport device 1 and the sound corresponding to the collected sound. Output a signal. Then, the jam detection unit 11 (a) generates a sample hold signal of the sound signal and attenuates it with a predetermined time constant, and (b) sets the timing at which the level of the sound signal exceeds a predetermined threshold value as the trigger timing Ttr. It is detected, (c) the fluctuation width according to the level of the sample hold signal at the detected trigger timing Ttr is accumulated to generate a detection signal, and (d) the occurrence of jam is detected based on the detection signal.

As a result, the jam-generated sound containing a relatively high-frequency component is distinguished from the low-frequency environmental sound based on the detection signal, so that erroneous detection of jam is suppressed.

FIG. 4 is a diagram illustrating a detection signal based on a low frequency environmental sound. In the case of environmental sound, the frequency of the sound signal is low, and as shown in FIG. 4, the time from the peak timing Tp of the sound signal to the trigger timing Ttr becomes long, and the amount of attenuation of the sample hold signal becomes large, so that the sampling timing Ts The increase in the detection signal in is smaller, the detection signal is not higher than in the case of the jam generation sound, and it is not determined that the jam has occurred. Therefore, false detection of jam is suppressed.

It should be noted that various changes and modifications to the above-described embodiments will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the intent and scope of the subject and without diminishing the intended benefits. That is, it is intended that such changes and amendments are included in the claims.

The present invention is applicable to, for example, an image forming apparatus.

1 Conveyor 2 Microphone 11 Jam detector

Claims (4)

A transport device that transports documents or printing paper,
A microphone that collects the sound generated by the transport device and outputs a sound signal corresponding to the collected sound.
(A) A sample hold signal of the sound signal is generated and attenuated by a predetermined time constant, (b) a timing when the level of the sound signal exceeds a predetermined threshold is detected as a trigger timing, and (c) the detected said A jam detection unit that accumulates the fluctuation range according to the level of the sample hold signal at the trigger timing to generate a detection signal, and (d) detects the occurrence of jam based on the level of the detection signal.
Equipped with a,
The predetermined time constant is set so that the level of the detected signal is increased by accumulating the fluctuation range according to the level of the sample hold signal each time the trigger timing is detected.
An image forming apparatus characterized by. The image forming apparatus according to claim 1, wherein the fluctuation width is proportional to the difference between the threshold value and the level of the sample hold signal at the detected trigger timing. The image forming apparatus according to claim 1, wherein the predetermined threshold value is a level different from the ground level. The image forming apparatus according to claim 1, wherein the jam detection unit performs a time averaging process on the detection signal and detects the occurrence of a jam based on the detection signal after the time averaging process.

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