LED linear light source and reading apparatus

Abstract

An LED linear light source includes an approximately rod-shaped light guiding member, at an end portion of which an LED is provided. The light guiding member is in an approximately arc shape in a cross sectional view taken perpendicular to an optical axis. The light guiding member has an upper face including a light emission face for emitting light and a lower face including a reflective face, which are arranged in parallel. A diffusing member diffuses light provided on part of an outer circumferential face adjacent to a light entering end face of the light guiding member. A light absorption member is provided in an outside of the light guiding member near at an end portion thereof.

Description

technical field

[0001] The invention relates to an LED linear light source and a reading device used in a manuscript illuminating device. In particular, it relates to an LED linear light source and a reading device in which LEDs are arranged at the end of a light guide. Background technique

[0002] Conventionally, a technology using a light emitting diode (LED) as a light source of a document lighting device is known. This technology is divided into the following two types: an array type in which a plurality of LEDs are arranged across the entire width direction of the document surface; The type of radiation transmitted to the light guide. Recently, with the increase in output of LEDs, the type using a light guide has attracted attention.

[0003] Examples of linear light sources using light guides include Japanese Patent Application Laid-Open No. 11-134918.

[0004] Figure 7 Represents the linear light source described in the above publication. The LED 71 is arranged...

Examples

Embodiment 1

[0053] figure 1 The first embodiment of the LED linear light source of the present invention is shown. The light guide body 1 is made of translucent acrylic resin and has a total length of 320 mm. figure 1 (a) shows a side view seen from the light incident portion 10 of the light guide 1 perpendicular to the optical axis direction, figure 1 (b) shows a measurement configuration diagram including the light receiving element 32, figure 1 (c) means figure 1 (b) A-A' sectional view.

[0054] The light guide 1 is composed of an upper surface 3 including an emission surface 2 , a lower surface 7 opposite to the upper surface 3 , and a side surface 8 connecting the upper surface 3 and the lower surface 7 . Reflecting surface 6 constituted by concave portion 4 and convex portion 5 is formed on lower surface 7 .

[0055] The light source 12 is composed of a light emitting diode 13 placed on a substrate; a hemispherical sealing body 14 sealing its outer periphery; and a reflec...

Embodiment 2

[0064] figure 2 It is the second embodiment of the LED linear light source of the present invention. The difference from the first embodiment is that a translucent diffusion sheet 37 is interposed between the lower surface 34 and the side surface 35 of the light guide body 33 and the diffusion reflection member 36 . As the translucent diffusion sheet 37, for example, 25MBC manufactured by Kimoto Co., Ltd. or the like can be used.

[0065] exist figure 2 In (a), the small rectangular member mounted on the glass 31 represents the light receiving element 32 . The light receiving element 32 can move in the Z direction, and the intensity distribution on the glass 31 can be measured.

[0066] figure 2 (b) shows the intensity distribution on the glass 31 . The vertical axis in this figure represents the relative intensity of light. Specifically, it shows that the measurement glass 31 on the original side is equivalent to and figure 1 (b) The intensity value of light at the...

technical field

[0001] The invention relates to an LED linear light source and a reading device used in a manuscript illuminating device. In particular, it relates to an LED linear light source and a reading device in which LEDs are arranged at the end of a light guide. Background technique

[0002] Conventionally, a technology using a light emitting diode (LED) as a light source of a document lighting device is known. This technology is divided into the following two types: an array type in which a plurality of LEDs are arranged across the entire width direction of the document surface; The type of radiation transmitted to the light guide. Recently, with the increase in output of LEDs, the type using a light guide has attracted attention.

[0003] Examples of linear light sources using light guides include Japanese Patent Application Laid-Open No. 11-134918.

[0004] Figure 7 Represents the linear light source described in the above publication. The LED 71 is arranged...

Examples

Embodiment 1

[0053] figure 1 The first embodiment of the LED linear light source of the present invention is shown. The light guide body 1 is made of translucent acrylic resin and has a total length of 320 mm. figure 1 (a) shows a side view seen from the light incident portion 10 of the light guide 1 perpendicular to the optical axis direction, figure 1 (b) shows a measurement configuration diagram including the light receiving element 32, figure 1 (c) means figure 1 (b) A-A' sectional view.

[0054] The light guide 1 is composed of an upper surface 3 including an emission surface 2 , a lower surface 7 opposite to the upper surface 3 , and a side surface 8 connecting the upper surface 3 and the lower surface 7 . Reflecting surface 6 constituted by concave portion 4 and convex portion 5 is formed on lower surface 7 .

[0055] The light source 12 is composed of a light emitting diode 13 placed on a substrate; a hemispherical sealing body 14 sealing its outer periphery; and a reflec...

Embodiment 2

[0064] figure 2 It is the second embodiment of the LED linear light source of the present invention. The difference from the first embodiment is that a translucent diffusion sheet 37 is interposed between the lower surface 34 and the side surface 35 of the light guide body 33 and the diffusion reflection member 36 . As the translucent diffusion sheet 37, for example, 25MBC manufactured by Kimoto Co., Ltd. or the like can be used.

[0065] exist figure 2 In (a), the small rectangular member mounted on the glass 31 represents the light receiving element 32 . The light receiving element 32 can move in the Z direction, and the intensity distribution on the glass 31 can be measured.

[0066] figure 2 (b) shows the intensity distribution on the glass 31 . The vertical axis in this figure represents the relative intensity of light. Specifically, it shows that the measurement glass 31 on the original side is equivalent to and figure 1 (b) The intensity value of light at the...

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