The colorimetry apparatus includes a light source for emitting light to a surface of a detected object, a diffraction grating for spectrally separating, for each wavelength, the light emitted from the light source and reflected by the detected object, and a line sensor including multiple pixels, for receiving the light, which is spectrally separated by the diffraction grating, for the each wavelength by the multiple pixels. The light source and the line sensor are arranged on the common substrate.

The colorimetry apparatus includes a light source for emitting light to a surface of a detected object, a diffraction grating for spectrally separating, for each wavelength, the light emitted from the light source and reflected by the detected object, and a line sensor including multiple pixels, for receiving the light, which is spectrally separated by the diffraction grating, for the each wavelength by the multiple pixels. The light source and the line sensor are arranged on the common substrate.

The colorimetry apparatus includes a light source for emitting light to a surface of a detected object, a diffraction grating for spectrally separating, for each wavelength, the light emitted from the light source and reflected by the detected object, and a line sensor including multiple pixels, for receiving the light, which is spectrally separated by the diffraction grating, for the each wavelength by the multiple pixels. The light source and the line sensor are arranged on the common substrate.

The colorimetry apparatus includes a light source for emitting light to a surface of a detected object, a diffraction grating for spectrally separating, for each wavelength, the light emitted from the light source and reflected by the detected object, and a line sensor including multiple pixels, for receiving the light, which is spectrally separated by the diffraction grating, for the each wavelength by the multiple pixels. The light source and the line sensor are arranged on the common substrate.

An image forming apparatus includes an image bearer to bear a visible image, a transfer device to transfer the visible image from the image bearer onto a recording medium, a separator to separate the recording medium from the image bearer, a separation bias application device to apply a separation bias to the separator; and a controller to control the separation bias. When the recording medium fed in the image forming apparatus is either a black sheet or a metallic sheet, the controller sets the separation bias smaller than a predetermined separation bias value for a reference sheet type other than the black sheet and the metallic sheet.