Image forming apparatus

1. An image forming apparatus, which is configured to include a sheet feeder cassette unit being opened or closed by extracting or inserting the sheet feeder cassette unit, comprising:

a vibration sensor configured to transmit detection signals in response to vibration patterns; and

an open/close detection unit configured to detect an open/close state of the sheet feeder cassette unit based on a detection result of the vibration sensor,

wherein the sheet feeder cassette unit generates a first specific vibration pattern when the sheet feeder cassette unit is opened or closed, and

the open/close detection unit identifies the first specific vibration pattern based on a detection signal of the vibration sensor and detects the open/close state of the sheet feeder cassette unit based on an identification of the first specific vibration pattern.

2. The image forming apparatus according to claim 1 ,

wherein the sheet feeder cassette unit generates a second specific vibration pattern being different from the first specific vibration pattern when the sheet feeder cassette unit is opened or closed, and

the open/close detection unit identifies the first specific vibration pattern and the second vibration pattern based on the detection signal of the vibration sensor, and identifies the open/close state of the sheet feeder cassette unit based on a detection order of the first specific vibration pattern and the second specific vibration pattern.

3. The image forming apparatus according to claim 1 ,

wherein a convex portion is formed on one side surface of an engagement surface of a guide rail of the sheet feeder cassette unit and another first concave portion or another convex portion is formed on another side surface of the engagement surface, and the first specific vibration pattern is generated by making the convex portion of the one side surface fit into the first concave portion or making the convex portion of the one side surface contact with another convex portion of another side surface when the sheet feeder cassette unit is extracted or inserted.

4. The image forming apparatus according to claim 3 , further comprising:

a second concave portion configured to generate a second specific vibration pattern being different from the first specific vibration pattern, the second concave portion being formed for an extraction direction or an insertion direction on another surface being opposite to the convex portion on the one side of surface at the engagement surface of the guide rail of the sheet feeder cassette unit,

wherein the second specific vibration pattern is generated when the sheet feeder cassette unit is extracted or inserted by making the convex portion of the one side surface fit into the second concave potion, and

the open/close detection unit identifies the open/close state of the sheet feeder cassette unit based on a detection order of the first specific vibration pattern and the second specific vibration pattern.

5. The image forming apparatus according to claim 1 , further comprising:

a plurality of sheet feeder cassette units configured to store recording papers, the plurality of sheet feeder cassette units being configured to generate a plurality of first specific vibration patterns being different from one another when each of the plurality of sheet feeder cassette units is opened or closed by extraction or insertion,

wherein the open/close detection unit identifies each of the first specific vibration patterns based on a detection signal of the vibration sensor, and identifies that a sheet feeder cassette unit is opened or closed based on each of the first specific vibration patterns.

6. The image forming apparatus according to claim 5 ,

wherein a convex portion is formed on one side surface of an engagement surface on a guide rail of each of the sheet feeder cassette units, each of the first concave portions having patterns or each of other convex portions having patterns is formed on another side surface of the engagement surface on the guide rail of each of the sheet feeder cassette units, each of the first specific vibration patterns of the sheet feeder cassette units is generated by making the convex portion of the one side surface fit into the first concave portions or making the convex portion of the one side surface contact with other convex portions of another side surface when each of the paper cassette is extracted or inserted.

7. The image forming apparatus according to claim 6 ,

wherein second concave portions are formed on each of the sheet feeder cassette units in an extraction direction or an insertion direction of another surface on the engagement surface on the guide rail of each of the sheet feeder cassette units, the second concave portions face the convex portion formed on the one surface of the engagement surface on the guide rail of each of the sheet feeder cassette units,

the second concave portions are configured to generate second vibration patterns, each of the second vibration patterns is different from each of the first vibration patterns,

each of the second vibration patterns is generated for each of the sheet feeder cassette units by that the convex portion of the one surface is fit into the second concave portions while each of the sheet feeder cassette units is extracted or inserted, and the open/close detection unit identifies the open/close state of each of the sheet feeder cassette units in response of an detection order of the first specific vibration pattern and the second specific vibration pattern.

8. The image forming apparatus according to claim 1 , further comprising:

a main body unit configured to include the vibration sensor and the open/close detection unit;

an optional sheet feeder cassette unit configured to include a sheet feeder cassette unit; and

a power control unit configured to control electric power supplied to the main body unit, the optional sheet feeder cassette unit, the power control unit being provided on the main body unit,

wherein the power control unit stops supplying the electric power to the optional sheet feeder cassette unit when the image forming apparatus is in sleep mode.