Abstract: An optical unit of plastic provided with a surface for incident light and a surface for outgoing light, wherein the surface for incident light is designed to face a light source and the surface for outgoing light is designed to face an element for receiving light so as to optically connect the light source and the element for receiving light and wherein the optical unit is so shaped that light that comes from the light source and is incident on the surface for incident light forms a first image of the light source within the optical unit and a second image of the light source after having gone through the surface for outgoing light and the optical unit is provided with an attenuating portion for attenuating the quantity of light passing therethrough in the vicinity of the position where the first image is formed.

Abstract: An ink cartridge and an ink storage device including the same are provided, which has a stable quality, lower ink residue, less components, lower cost, and low impact to the environment. The ink storage device is assembled by an ink receiving portion, a sleeve, and a pin plug. The ink receiving portion is formed by welding and sealing the edges of a pair of plates. The sleeve has a first end portion and a respective second end portion. The first end portion is connected to the ink receiving portion and the second end portion exposes out of the ink receiving portion. An interior of the sleeve has a penetrating hole connecting the ink receiving portion. The pin plug is made of an elastic material and is installed to the second end portion of the sleeve. A storage portion for storing the ink is formed in the pin plug, and an end of the pin plug is formed as a linking hole linking the ink receiving portion with the storage portion through the penetrating hole.