Powder detector, image forming apparatus including same, and powder detecting method

Patent metadata

Field	Value
Publication number	US-9523664-B2
Application number	US-201514884961-A
Country	US
Kind code	B2
Filing date	Oct 16, 2015
Priority date	Oct 23, 2014
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

A powder detector to detect an amount of powder in the powder container includes a vibration plate disposed in the powder container to vibrate, a contact member to vibrate the vibration plate; and a vibration detector to detect a vibration state of the vibration plate. The powder has flowability, and the vibration state of the vibration plate is affected by the powder in the powder container.

First claim

What is claimed is:

1. A powder detector to detect an amount of powder in a powder container, the powder having flowability, the powder detector comprising:
a vibration plate disposed in the powder container to vibrate;
a contact member to vibrate the vibration plate; and
a vibration detector to detect a vibration state of the vibration plate,
wherein the vibration state of the vibration plate is affected by the powder in the powder container.

2. The powder detector according to claim 1 , wherein the contact member comprises an agitator to agitate the powder in the powder container.

3. The powder detector according to claim 1 , further comprising a shaft to rotate inside the powder container,
wherein the contact member is attached to the shaft to rotate together with the shaft,
a first end of the vibration plate in an axial direction of the shaft is secured, and
the vibration plate includes a projection projecting toward the shaft from a second end opposite the first end, the projection pressed by the contact member.

4. The powder detector according to claim 3 , wherein the projection comprises an inclined face projecting from a face of the vibration plate, the inclined face inclined to reduce a distance from the shaft along a direction of rotation of the contact member.

5. The powder detector according to claim 3 , wherein the projection is different in material from the vibration plate, and
the vibration plate including the projection has a predetermined vibration frequency.

6. The powder detector according to claim 1 , further comprising:
a frequency-related data output to output frequency-related data; and
a detection result processor to acquire, in each predetermined sampling cycle, the frequency-related data from the frequency-related data output,
wherein the vibration detector comprises a signal oscillator to output an oscillation signal having a frequency corresponding to a state of a magnetic flux passing through a space opposed to the vibration detector,
the frequency-related data relates to the frequency of the oscillation signal of the signal oscillator and changes corresponding to the vibration state of the vibration plate,
the vibration plate is made of a material to affect the magnetic flux and disposed facing the signal oscillator via a housing of the powder container to vibrate in a direction in which the vibration plate faces the signal oscillator, and
the detection result processor detects the vibration state of the vibration plate based on a change in the frequency-related data and recognizes the amount of the powder in the powder container.

7. The powder detector according to claim 6 , wherein the frequency-related data changes corresponding to an attenuation of vibration of the vibration plate vibrated by the contact member.

8. The powder detector according to claim 7 , wherein the frequency-related data includes a count value of the oscillation signal output from the signal oscillator, the count value counted in the predetermined sampling cycle, and
the detection result processor detects the vibration state of the vibration plate based on a change in the count value.

9. The powder detector according to claim 8 , wherein the count value of the oscillation signal acquired by the detection result processor includes a first count value and a second count value counted at different timings, and
the detection result processor detects the vibration state of the vibration plate based on a ratio between the first count value and the second count value.

10. The powder detector according to claim 9 , wherein the detection result processor determines that the amount of the powder in the powder container is below a prescribed amount based on a comparison between a threshold and the ratio between the first count value and the second count value.

11. The powder detector according to claim 6 , wherein the sampling cycle in which the detection result processor acquires the frequency-related data is shorter than a vibration cycle of the vibration plate.

12. The powder detector according to claim 6 , wherein the signal oscillator comprises a coil disposed on a board to generate a magnetic flux in the direction in which the vibration plate faces the signal oscillator, and
the signal oscillator outputs the oscillation signal having a frequency corresponding to an inductance of the coil.

13. An image forming apparatus comprising:
an image forming unit to form an image;
the powder container; and
the powder detector according to claim 1 ,
wherein the powder container contains a powder used by the image forming unit to form the image.

14. A powder detecting method to detect an amount of powder in a powder container, the powder having flowability, the powder detecting method comprising:
vibrating, using a contact member, a vibration plate disposed on the powder container;
detecting, with a vibration detector, a vibration state of the vibration plate; and
recognizing the amount of the powder in the powder container according to the vibration state detected,
wherein the vibration state of the vibration plate is affected by the powder in the powder container.

15. The powder detecting method according to claim 14 , wherein the vibration detector comprises a signal oscillator to output an oscillation signal having a frequency corresponding to a state of a magnetic flux passing through a space opposed to the vibration detector,
the vibration plate is disposed facing the signal oscillator via a housing of the powder container and to vibrate in a direction in which the vibration plate faces the signal oscillator,
the vibration plate is made of a material to affect the magnetic flux,
the powder detecting method further comprises:
outputting, from the signal oscillator, the oscillation signal having the frequency corresponding to the state of the magnetic flux passing through the space opposed;
acquiring, in each predetermined sampling cycle, frequency-related data that relates to the frequency of the oscillation signal of the signal oscillator and changes corresponding to the vibration state of the vibration plate;
detecting the vibration state of the vibration plate based on a change in the frequency-related data, and
recognizing the amount of the powder in the powder container according to the vibration state detected.

Assignees

• Hirota Tetsuro
• Kikuchi Kenji
• Hosokawa Hiroshi
• Ricoh Co Ltd

Inventors

• Hirota Tetsuro
• Kikuchi Kenji
• Hosokawa Hiroshi

Classifications

• G03G15/0858 Primary

  the level being measured by mechanical means · CPC title

• G03G15/086 Primary

  the level being measured by electro-magnetic means · CPC title

• G03G15/0889

  for agitation or stirring · CPC title

• G01M7/02

  Vibration-testing {by means of a shake table} · CPC title

• G01N33/00 Primary

  Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00 · CPC title