Sensor IC, contact image sensor and image reading apparatus

A sensor IC, comprising:

• a plurality of light receiving portions including a first light receiving portion that receives light of a first wavelength and a second light receiving portion that receives light of a second wavelength different from the first wavelength, the light receiving portions being arranged in a row along a primary scanning direction;
• a plurality of additional light receiving portions provided at different positions from said plurality of light receiving portions in a secondary scanning direction, the additional light receiving portions being arranged in a row along the primary scanning direction, the additional light receiving portions including a third light receiving portion that receives light of a third wavelength different from the first wavelength and the second wavelength;
• and
• a control circuit that outputs a first electric signal corresponding to light of the first wavelength received by the first light receiving portion, a second electric signal corresponding to light of the second wavelength received by the second light receiving portion, and a third electric signal corresponding to light of the third wavelength received by the third light receiving portion,
• wherein said plurality of light receiving portions include a plurality of first light receiving portions and a plurality of second light receiving portions, the first light receiving portions and the second light receiving portions being alternately arranged,
• said plurality of additional light receiving portions include a plurality of third light receiving portions and a plurality of fourth light receiving portions that receive light of a wavelength different from light of the third wavelength,
• the third light receiving portions and the fourth light receiving portions are alternately arranged,
• the first light receiving portions, the second light receiving portions and the third light receiving portions receive visible light, and
• the fourth light receiving portions receive light of a fourth wavelength included in an invisible light range.

A contact image sensor comprising:

• a sensor IC, provided with:
• a plurality of light receiving portions including a first light receiving portion that receives light of a first wavelength, a second light receiving portion that receives light of a second wavelength different from the first wavelength, and a third light receiving portion that receives light of a third wavelength different from the first wavelength and the second wavelength, the light receiving portions being arranged in a row along a primary scanning direction;
• and
• a control circuit that outputs a first electric signal corresponding to light of the first wavelength received by the first light receiving portion, a second electric signal corresponding to light of the second wavelength received by the second light receiving portion, and a third electric signal corresponding to light of the third wavelength received by the third light receiving portion;
• wherein the first light receiving portion, the second light receiving portion and the third light receiving portion receive visible light,
• the light receiving portions include a fourth light receiving portion that receives light of a fourth wavelength included in an invisible light range, and
• the control circuit outputs a fourth electric signal corresponding to light received by the fourth light receiving portion;
• a light source that emits light of the first wavelength, light of the second wavelength, light of the third wavelength and light of the fourth wavelength for illuminating a read object;
• and
• a lens array that focuses light from the read object onto the sensor IC to form an erected equal-magnification image.

An image reading apparatus, comprising:

• a sensor IC, provided with:
• a plurality of light receiving portions including a first light receiving portion that receives light of a first wavelength, a second light receiving portion that receives light of a second wavelength different from the first wavelength, and a third light receiving portion that receives light of a third wavelength different from the first wavelength and the second wavelength, the light receiving portions being arranged in a row along a primary scanning direction;
• and
• a control circuit that outputs a first electric signal corresponding to light of the first wavelength received by the first light receiving portion, a second electric signal corresponding to light of the second wavelength received by the second light receiving portion, and a third electric signal corresponding to light of the third wavelength received by the third light receiving portion;
• a light source that emits light of the first wavelength, light of the second wavelength and light of the third wavelength for illuminating a read object;
• a lens array that focuses light from the read object onto the sensor IC to form an erected equal-magnification image;
• and
• a signal processor that receives the first electric signal, the second electric signal and the third electric signal,
• wherein the signal processor outputs a plurality of picture element information pieces, each of which includes:
• a first color information piece based on the first electric signal;
• a second color information piece based on the second electric signal;
• and a third color information piece based on the third electric signal and
• every time the sensor IC performs scanning, the signal processor outputs a larger number of picture element information pieces than a number of the first light receiving portions.

An image reading apparatus comprising:

• a contact image sensor including a sensor IC, a light source and a lens array;
• a transferer;
• a controller;
• and
• a signal processor;
• wherein the sensor IC comprises:
• a plurality of light receiving portions including a first light receiving portion that receives light of a first wavelength and a second light receiving portion that receives light of a second wavelength different from the first wavelength, the light receiving portions being arranged in a row along a primary scanning direction;
• a plurality of additional light receiving portions provided at different positions from said plurality of light receiving portions in a secondary scanning direction, the additional light receiving portions being arranged in a row along the primary scanning direction, the additional light receiving portions including a third light receiving portion that receives light of a third wavelength different from the first wavelength and the second wavelength;
• and
• a control circuit that outputs a first electric signal corresponding to light of the first wavelength received by the first light receiving portion, a second electric signal corresponding to light of the second wavelength received by the second light receiving portion, and a third electric signal corresponding to light of the third wavelength received by the third light receiving portion;
• wherein the light source emits light of the first wavelength, light of the second wavelength and light of the third wavelength for illuminating a read object,
• the lens array focuses light from the read object onto the sensor IC to form an erected equal-magnification image,
• the transferer is configured to move the read object relative to the contact image sensor,
• the controller is configured to control the transferer, and
• the signal processor is configured to receive the first electric signal, the second electric signal and the third electric signal,
• wherein the signal processor outputs a plurality of picture element information pieces each of which includes:
• a first color information piece based on the first electric signal;
• a second color information piece based on the second electric signal;
• and a third color information piece based on the third electric signal.