Optical scanning device and image forming apparatus

An optical scanning device comprising:

• a light source configured to emit a luminous flux;
• a rotatable polygon mirror configured to deflect the luminous flux emitted from the light source and scan in a main scanning direction;
• a first optical member configured to guide the luminous flux scanned by the rotatable polygon mirror to an image bearing member;
• a second optical member provided on an upstream side of the first optical member in the main scanning direction;
• an output unit provided on the upstream side of the first optical member in the main scanning direction and configured to output a signal corresponding to receiving the luminous flux which is scanned by the rotatable polygon mirror and condensed in the main scanning direction by the second optical member;
• a reflecting member provided on the upstream side of the second optical member in the main scanning direction and configured to reflect the luminous flux scanned by the rotatable polygon mirror and guide to the output unit without passing through the second optical member;
• and
• a control unit configured to control the light source based on the signal outputted from the output unit,
• wherein the output unit detects a light quantity of the luminous flux which is the upstream side, in the main scanning direction, of the luminous flux condensed in the main scanning direction by the second optical member and which is not condensed in the main scanning direction, and
• wherein the control unit controls the light quantity of the luminous flux not condensed in the main scanning direction.

An optical scanning device, comprising:

• a light source configured to emit a luminous flux;
• a rotatable polygon mirror configured to deflect the luminous flux emitted from the light source and scan in a main scanning direction;
• a first optical member configured to guide the luminous flux scanned by the rotatable polygon mirror to an image bearing member;
• a second optical member provided on an upstream side of the first optical member in the main scanning direction;
• an output unit provided on the upstream side of the first optical member in the main scanning direction and configured to output a signal corresponding to receiving the luminous flux which is scanned by the rotatable polygon mirror and condensed in the main scanning direction by the second optical member;
• and
• a control unit configured to control the light source based on the signal outputted from the output unit,
• wherein the output unit detects a light quantity of the luminous flux which is the upstream side, in the main scanning direction, of the luminous flux condensed in the main scanning direction by the second optical member and which is not condensed in the main scanning direction,
• wherein the control unit controls the light quantity of the luminous flux not condensed in the main scanning direction, and
• wherein the second optical member includes a first portion configured to cause the luminous flux scanned by the rotatable polygon mirror to condense in the main scanning direction and to enter the output unit, and a second portion provided on the upstream side of the first portion in the main scanning direction and configured to cause the luminous flux scanned by the rotatable polygon mirror not to condense in the main scanning direction and to enter the output unit.