Abstract: An image reading apparatus includes a cover, a reading device including a light source and a sensor, and a control device including circuitry. The circuitry acquires first data with the light source turned off, acquires second data with the light source turned on, calculates a first evaluation value for each of plural locations of the first data, calculates a second evaluation value for each of plural locations of the second data, determines an open or closed state of the cover based on the first evaluation value and the second evaluation value, determines that the cover is open when at least one of a determination result based on the first evaluation value or a determination result based on the second evaluation value indicates the open state of the cover, and determines that the cover is closed when the two determination results both indicate the closed state of the cover.

Abstract: An image reading apparatus includes a cover, a reading device including a light source and a sensor, and a control device including circuitry. The circuitry acquires first data with the light source turned off, acquires second data with the light source turned on, calculates a first evaluation value for each of plural locations of the first data, calculates a second evaluation value for each of plural locations of the second data, determines an open or closed state of the cover based on the first evaluation value and the second evaluation value, determines that the cover is open when at least one of a determination result based on the first evaluation value or a determination result based on the second evaluation value indicates the open state of the cover, and determines that the cover is closed when the two determination results both indicate the closed state of the cover.

Abstract: An image scanner includes: an image sensor that photo-electrically converts reflected light from a document irradiated with light by a light source; an A/D converter that converts an analog image signal output from the image sensor into a digital signal; a lighting control unit that adjusts, in a period other than a document scanning period, a lighting period of the light source so that the light source is turned on and off alternately in a repetitive manner in units of a line cycle; a black correction unit that generates reference black data used for black correction based on effective pixel data in a light source non-lighting period in the period other than the document scanning period; and a white correction unit that generates shading data used for shading correction based on effective pixel data in a light source lighting period in the period other than the document scanning period.

Abstract: The ratio between first reference data which is acquired by scanning the surface of a white member in a state where the size of a gap is substantially equal to that when a document is scanned and second reference data which is acquired by scanning the surface of the white member in a state where the size of the gap is smaller than that when the document is scanned is calculated as a reference data ratio, and the reference data ratio is stored. In generating shading data for correcting image data of each document, the reference data ratio being stored is multiplied by third reference data which is acquired by scanning the surface of the white member in a state where the size of the gap is substantially equal to that when the document is scanned, thereby generating shading data.

Abstract: An image scanner includes: an image sensor that photo-electrically converts reflected light from a document irradiated with light by a light source; an A/D converter that converts an analog image signal output from the image sensor into a digital signal; a lighting control unit that adjusts, in a period other than a document scanning period, a lighting period of the light source so that the light source is turned on and off alternately in a repetitive manner in units of a line cycle; a black correction unit that generates reference black data used for black correction based on effective pixel data in a light source non-lighting period in the period other than the document scanning period; and a white correction unit that generates shading data used for shading correction based on effective pixel data in a light source lighting period in the period other than the document scanning period.

Abstract: The ratio between first reference data which is acquired by scanning the surface of a white member in a state where the size of a gap is substantially equal to that when a document is scanned and second reference data which is acquired by scanning the surface of the white member in a state where the size of the gap is smaller than that when the document is scanned is calculated as a reference data ratio, and the reference data ratio is stored. In generating shading data for correcting image data of each document, the reference data ratio being stored is multiplied by third reference data which is acquired by scanning the surface of the white member in a state where the size of the gap is substantially equal to that when the document is scanned, thereby generating shading data.

Abstract: In order to provide light emitting devices which have simple constructions and thus can be fabricated easily, and can stably provide high light emission efficiencies for a long time period, a light emitting device includes an n-type nitride semiconductor layer at a first main surface side of a nitride semiconductor substrate, a p-type nitride semiconductor layer placed more distantly from the nitride semiconductor substrate than the n-type nitride semiconductor layer at the first main surface side and a light emitting layer placed between the n-type nitride semiconductor layer and the p-type nitride semiconductor layer at the first main surface side. The nitride semiconductor substrate has a resistivity of 0.5 ?·cm or less and the p-type nitride semiconductor layer side is down-mounted so that light is emitted from the second main surface of the nitride semiconductor substrate at the opposite side from the first main surface.

Abstract: A light emitting device having a simple structure that can be easily manufactured, attaining high light emitting efficiency stably for a long time is obtained, which light emitting device includes: a GaN substrate as a nitride semiconductor substrate and, on a first main surface of the nitride semiconductor substrate, an n-type AlxGa1-xN layer, a p-type AlxGa1-xN layer positioned further than the n-type AlxGa1-xN layer viewed from the nitride semiconductor substrate, and a quantum well positioned between the n-type AlxGa1-xN layer and the p-type AlxGa1-xN layer. In the light emitting device, specific resistance of the nitride semiconductor substrate is at most 0.5 ?·cm, the side of p-type AlxGa1-xN layer is mounted face-down, and the light is emitted from the second main surface 1a that is opposite to the first main surface of the nitride semiconductor substrate. The second main surface 1a of nitride semiconductor substrate has trenches formed therein.

Abstract: In order to provide light emitting devices which have simple constructions and thus can be fabricated easily, and can stably provide high light emission efficiencies for a long time period, a light emitting device includes an n-type nitride semiconductor layer at a first main surface side of a nitride semiconductor substrate, a p-type nitride semiconductor layer placed more distantly from the nitride semiconductor substrate than the n-type nitride semiconductor layer at the first main surface side and a light emitting layer placed between the n-type nitride semiconductor layer and the p-type nitride semiconductor layer at the first main surface side. The nitride semiconductor substrate has a resistivity of 0.5 ?·cm or less and the p-type nitride semiconductor layer side is down-mounted so that light is emitted from the second main surface of the nitride semiconductor substrate at the opposite side from the first main surface.

Abstract: In order to provide light emitting devices which have simple constructions and thus can be fabricated easily, and can stably provide high light emission efficiencies for a long time period, a light emitting device includes an n-type nitride semiconductor layer at a first main surface side of a nitride semiconductor substrate, a p-type nitride semiconductor layer placed more distantly from the nitride semiconductor substrate than the n-type nitride semiconductor layer at the first main surface side and a light emitting layer placed between the n-type nitride semiconductor layer and the p-type nitride semiconductor layer at the first main surface side. The nitride semiconductor substrate has a resistivity of 0.5 ?·cm or less and the p-type nitride semiconductor layer side is down-mounted so that light is emitted from the second main surface of the nitride semiconductor substrate at the opposite side from the first main surface.

Abstract: A light emitting device includes a nitride semiconductor substrate with a resistivity of 0.5 ?·cm or less, an n-type nitride semiconductor layer and a p-type nitride semiconductor layer placed more distantly from the nitride semiconductor substrate than the n-type nitride semiconductor layer at a first main surface side of the nitride semiconductor substrate, and a light emitting layer placed between the n-type nitride semiconductor layer and the p-type nitride semiconductor layer, wherein one of the nitride semiconductor substrate and the p-type nitride semiconductor layer is mounted at the top side which emits light and the other is placed at the down side, and a single electrode is placed at the top side. Therefore, there is provided a light emitting device which has a simple configuration thereby making it easy to fabricate, can provide a high light emission efficiency for a long time period, and can be easily miniaturized.

Abstract: A light emitting device having a simple structure that can be easily manufactured, attaining high light emitting efficiency stably for a long time is obtained, which light emitting device includes: a GaN substrate as a nitride semiconductor substrate and, on a first main surface of the nitride semiconductor substrate, an n-type AlxGa1-xN layer, a p-type AlxGa1-xN layer positioned further than the n-type AlxGa1-xN layer viewed from the nitride semiconductor substrate, and a quantum well positioned between the n-type AlxGa1-xN layer and the p-type AlxGa1-xN layer. In the light emitting device, specific resistance of the nitride semiconductor substrate is at most 0.5 ?·cm, the side of p-type AlxGa1-xN layer is mounted face-down, and the light is emitted from the second main surface 1a that is opposite to the first main surface of the nitride semiconductor substrate. The second main surface 1a of nitride semiconductor substrate has trenches formed therein.

Abstract: A light emitting device includes a nitride semiconductor substrate with a resistivity of 0.5 ?·cm or less, an n-type nitride semiconductor layer and a p-type nitride semiconductor layer placed more distantly from the nitride semiconductor substrate than the n-type nitride semiconductor layer at a first main surface side of the nitride semiconductor substrate, and a light emitting layer placed between the n-type nitride semiconductor layer and the p-type nitride semiconductor layer, wherein one of the nitride semiconductor substrate and the p-type nitride semiconductor layer is mounted at the top side which emits light and the other is placed at the down side, and a single electrode is placed at the top side. Therefore, there is provided a light emitting device which has a simple configuration thereby making it easy to fabricate, can provide a high light emission efficiency for a long time period, and can be easily miniaturized.

Abstract: A light-emitting diode (1) is furnished with a semiconductor laminate (6), optically reflective layers (17) and (19), an optically reflective film (25), and a phosphorescent plate (27). The laminate (6) is formed by an n-type cladding layer (9), an active layer (11), a p-type cladding layer (13), and a p-type contact layer (15), laminated in order onto a substrate (7). The optically reflective layers (17) and (19) are provided respectively on the p-type contact layer (15) and on the back side (7b) of the substrate (7). The optically reflective film (25) is provided on three side surfaces of the laminate (6). The phosphorescent plate (27) is mounted on a side face, among the side faces of the laminate (6), on which there is no optically reflective film (25). Blue light (L1) output from the active layer (11) is reflected at each of the optically reflective layers, and is gathered on the side face on which the phosphorescent plate (27) is provided.

Abstract: A semiconductor light emitting device includes: a first conductivity type semiconductor layer made of nitride semiconductor; a second conductivity type semiconductor layer made of nitride semiconductor, the second conductivity type semiconductor layer being provided on the first conductivity type semiconductor layer; an active layer made of nitride semiconductor, the active layer being provided between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; a first electrode electrically connected to the first conductivity type semiconductor layer; a second electrode provided on the second conductivity type semiconductor layer, the second electrode having a predetermined pattern; and a reflecting metal layer provided on the second conductivity type semiconductor layer and the second electrode.

Abstract: In order to provide light emitting devices which have simple constructions and thus can be fabricated easily, and can stably provide high light emission efficiencies for a long time period, a light emitting device includes an n-type nitride semiconductor layer at a first main surface side of a nitride semiconductor substrate, a p-type nitride semiconductor layer placed more distantly from the nitride semiconductor substrate than the n-type nitride semiconductor layer at the first main surface side and a light emitting layer placed between the n-type nitride semiconductor layer and the p-type nitride semiconductor layer at the first main surface side. The nitride semiconductor substrate has a resistivity of 0.5 ?·cm or less and the p-type nitride semiconductor layer side is down-mounted so that light is emitted from the second main surface of the nitride semiconductor substrate at the opposite side from the first main surface.