Recording material determination apparatus and image forming apparatus that receive ultrasonic waves

Patent metadata

Field	Value
Publication number	US-10915052-B2
Application number	US-201916717130-A
Country	US
Kind code	B2
Filing date	Dec 17, 2019
Priority date	Dec 26, 2018
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

A recording material determination apparatus includes a transmission unit, a reception unit, and a determination unit. The transmission unit transmits an ultrasonic wave to a recording material. The reception unit vibrates when the reception unit receives the ultrasonic wave having been transmitted from the transmission unit and having passed through the recording material, and outputs a signal corresponding to a vibration state. The determination unit determines a basis weight of the recording material in accordance with the signal output from the reception unit. A resonance frequency of the reception unit differs from a resonance frequency of the transmission unit, and the reception unit is capable of receiving a sound wave in an ultrasonic range and a sound wave in an audible range.

First claim

What is claimed is:

1. A recording material determination apparatus comprising:
a transmission unit configured to transmit an ultrasonic wave to a recording material;
a reception unit configured to vibrate when the reception unit receives the ultrasonic wave having been transmitted from the transmission unit and having passed through the recording material, and configured to output a signal corresponding to a vibration state; and
a determination unit configured to determine a basis weight of the recording material in accordance with the signal output from the reception unit,
wherein a resonance frequency of the reception unit differs from a resonance frequency of the transmission unit, and the resonance frequency of the reception unit is in a range of an audible sound.

2. The recording material determination apparatus according to claim 1 , wherein a first reception sensitivity of the reception unit at a frequency of the ultrasonic wave transmitted from the transmission unit is not less than −45 voltage decibels (dBV) and is lower than a second reception sensitivity at the resonance frequency of the reception unit by not less than 6 dBV.

3. The recording material determination apparatus according to claim 1 , wherein the reception unit includes a vibrating membrane configured to vibrate when the vibrating membrane receives an ultrasonic wave, and includes an electrode provided opposite the vibrating membrane and configured to output a signal corresponding to a vibration state of the vibrating membrane.

4. The recording material determination apparatus according to claim 3 , wherein, when the vibrating membrane receives an ultrasonic wave and vibrates, a change in capacitance between the vibrating membrane and the electrode is converted into the signal corresponding to the vibration state of the vibrating membrane.

5. The recording material determination apparatus according to claim 3 , wherein a hole through which an ultrasonic wave passes is formed in the electrode, and the electrode is provided at a distance to the transmission unit that is smaller than a distance between the vibrating membrane and the transmission unit.

6. The recording material determination apparatus according to claim 1 , wherein the reception unit is a micro-electro-mechanical system (MEMS) microphone.

7. The recording material determination apparatus according to claim 1 , wherein the resonance frequency of the transmission unit is in a range of an ultrasonic wave.

8. The recording material determination apparatus according to claim 1 , wherein a range of the audible sound is from 20 Hz to 20 kHz, and a range of the ultrasonic wave is greater than 20 kHz.

9. The recording material determination apparatus according to claim 1 , wherein the reception unit is configured to output a signal which is not less than a predetermined voltage when the reception unit receives each of an ultrasonic wave and an audible sound.

10. The recording material determination apparatus according to claim 1 , wherein a reception sensitivity of the reception unit at a frequency of the audible sound is not less than −40 voltage decibels (dBV).

11. An image forming apparatus comprising:
an image forming unit configured to form an image on a recording material;
a transmission unit configured to transmit an ultrasonic wave to the recording material;
a reception unit configured to vibrate when the reception unit receives the ultrasonic wave having been transmitted from the transmission unit and having passed through the recording material, and configured to output a signal corresponding to a vibration state; and
a control unit configured to control an image forming condition for the recording material in accordance with the signal output from the reception unit,
wherein a resonance frequency of the reception unit differs from a resonance frequency of the transmission unit, and the resonance frequency of the reception unit is in a range of an audible sound.

12. The image forming apparatus according to claim 11 , wherein a first reception sensitivity of the resonance frequency of the reception unit of the ultrasonic wave transmitted from the transmission unit is not less than −45 voltage decibels (dBV) and is lower than a second reception sensitivity at the reception unit resonance frequency by not less than 6 dBV.

13. The image forming apparatus according to claim 11 , wherein the reception unit includes a vibrating membrane configured to vibrate when the vibrating membrane receives an ultrasonic wave, and includes an electrode provided opposite the vibrating membrane and configured to output a signal corresponding to a vibration state of the vibrating membrane.

14. The image forming apparatus according to claim 13 , wherein, when the vibrating membrane receives an ultrasonic wave and vibrates, a change in capacitance between the vibrating membrane and the electrode is converted into the signal corresponding to the vibration state of the vibrating membrane.

15. The image forming apparatus according to claim 13 , wherein a hole through which an ultrasonic wave passes is formed in the electrode, and the electrode is provided at a distance to the transmission unit that is smaller than a distance between the vibrating membrane and the transmission unit.

16. The image forming apparatus according to claim 11 further comprising a conveyance unit configured to convey the recording material,
wherein a detection operation, in which the transmission unit transmits an ultrasonic wave and the reception unit receives the ultrasonic wave having passed through the recording material and outputs a signal, is performed a plurality of times on the recording material being conveyed by the conveyance unit.

17. The image forming apparatus according to claim 11 , wherein the image forming condition includes at least any one of a conveyance speed of the recording material, a voltage value applied to a transfer unit included in the image forming unit when the transfer unit transfers an image onto the recording material, and a temperature at which a fixing unit included in the image forming unit fixes an image to the recording material.

18. The image forming apparatus according to claim 11 , wherein the reception unit is a micro-electro-mechanical system (MEMS) microphone.

19. The image forming apparatus according to claim 11 , wherein the resonance frequency of the transmission unit is in a range of an ultrasonic wave.

20. The image forming apparatus according to claim 11 , wherein a range of the audible sound is from 20 Hz to 20 kHz, and a range of the ultrasonic wave is greater than 20 kHz.

21. The image forming apparatus according to claim 11 , wherein the reception unit is configured to output a signal which is not less than a predetermined voltage when the reception unit receives each of an ultrasonic wave and an audible sound.

22. The image forming apparatus according to claim 11 , wherein a reception sensitivity of the reception unit at a frequency of the audible sound is not less than −40 voltage decibels (dBV).

Assignees

• Canon Kk

Inventors

• Azami Junya
• Monde Masafumi
• Kumada Hiromitsu
• Fujii Yuka
• Ishimoto Mizuki

Classifications

• G03G15/5029 Primary

  by measuring the copy material characteristics, e.g. weight, thickness · CPC title

• G03G2215/00742

  of sheet weight · CPC title

• G03G2215/00637

  Acoustic detector · CPC title

• G03G2215/00324

  Document property detectors · CPC title