TWI615015B - Lighting module and image capture apparatus - Google Patents

Abstract

The present invention provides a light source module and an image capturing device. The light source module includes a substrate, a light guiding rod and a plurality of light emitting diodes. The light guiding rod has a light incident surface and a light emitting surface, and the light emitting surface is adjacent to the light incident surface. The light emitting diodes are arranged on the substrate along a first axis and project light toward the light incident surface, and a distance between an optical axis of each of the light emitting diodes and the first axis is not more than 0.5 mm. The image capturing device includes the light source module, a base, an imaging module and a sensing module. The light source module is mounted in the base and emits light toward an object; the imaging module is mounted in the base and used for The light reflected by the object is imaged on a sensing module located on the other side of the base.

Description

Light source module and image capturing device

This creation relates to a method or apparatus for reading or recognizing printed or written text or for recognizing a graphic, and in particular to a line image sensor.

A contact image sensor is a type of line image sensor mainly used in scanners, fax machines, and multifunction printers to scan flat images or documents into an electronic format for storage. , display or transfer.

The working principle of the contact image sensor is to irradiate the light generated by the light source onto the manuscript to be scanned, reflect the light through the manuscript, and focus the reflected light on the photosensitive member by using a lens group; The signal is changed to an electrical signal, which in turn produces analog or digital pixel data.

At present, the light source generally used in the contact image sensing device on the market mainly provides a white light to illuminate the object; however, the light-emitting diode with the blue light-emitting crystal grain and the yellow fluorescent powder to generate white light may cause color rendering due to poor color rendering. The image quality is poor.

According to the present invention, a light source module is provided for use in an image taking device; the light source module includes a substrate, a light guiding rod and a plurality of light emitting diodes. The light guiding rod has a light incident surface and a light emitting surface, and the light emitting surface is adjacent to the light incident surface. The light emitting diodes are disposed on the substrate and arranged along a first axis and project light toward the light incident surface, and a distance between an optical axis of each of the light emitting diodes and the first axis is not more than 0.5 mm. Second, the first axis is parallel to one of the normals of the light exit surface.

In one embodiment of the present invention, the light-emitting diodes in the light source module cooperate to generate a white light, and in the light-emitting diode of the light source module, the light-emitting diodes disposed closest to the light-emitting surface are arranged to generate wavelengths. In the light of 606~626 nm, the light-emitting diodes adjacent to the light-emitting surface are arranged to generate light having a wavelength of 508-555 nm, and the light-emitting diodes arranged farthest from the light-emitting surface are generated for a wavelength of 450~ 480 nm of light.

In one embodiment of the present invention, the plurality of microprisms of the light guiding rod are formed on a bottom surface of the light guiding rod, and the bottom surface is opposite to the light emitting surface; the density of the microprism is inversely proportional to the intensity of the light received by the laying position.

In one embodiment of the present invention, the light source module further includes a reflective member mounted on the substrate, and one side wall of the reflective member surrounds the light emitting diodes, and an inner diameter of the sidewall increases as the distance from the substrate increases.

In one embodiment of the present invention, the reflective member further includes a bottom wall connected to the side wall adjacent to one side of the substrate, and the light emitting diode is disposed on the bottom wall.

In an embodiment of the present invention, the light source module further includes a joint member, the light emitting diode and the reflector are disposed on one side of the joint member, and the light guide rod is mounted on the other side of the joint member to receive the light emitting diode. The white light produced.

In one embodiment of the present invention, the light source module further includes a protective member, and some of the light guiding rods are covered, and the light incident surface and the light emitting surface expose the protective member.

According to the present invention, an image capturing device is provided for capturing an image of an object; the image capturing device comprises the foregoing light source module, a base, a sensing module and an imaging module. The base includes a receiving slot and a through slot, and the light source module is disposed in the receiving slot, and the object is located on one side of the base. The sensing module is located on the other side of the base and includes a plurality of photosensitive members arranged along a second axis. The imaging module is mounted in the slot and is used to image the image of the object to the photosensitive member.

In one embodiment of the present invention, the angle between the first axis and the optical axis of one of the photosensitive members is between 35 and 65 degrees.

The image capturing device of the present invention provides a high color rendering white light source to illuminate an object by appropriately arranging the light emitting diodes of the light source module for generating blue, green and red light and their relative positions with the light emitting surface. Achieve improved imaging quality.

1 is a perspective exploded view of the image capturing apparatus according to the present invention, and FIG. 2 is a partially exploded view of the image capturing apparatus according to the present invention. In FIG. 1 and FIG. 2, the image capturing device 1 is configured to sense an image of a (planar) object and convert the optical image of the object into an analog or digital electronic signal for storage and transmission. The image capturing device 1 includes a body 10, a light source module 12, an imaging module 14, and a sensing module 16.

The base 10 includes a top surface 100, a bottom surface 102 opposite to the top surface 100, a receiving groove 104, and a through groove 106. The bottom surface 102 is substantially parallel to the top surface 100. The accommodating groove 104 is formed on the top surface 100 and is recessed toward the bottom surface 102. The through groove 106 is a slot structure penetrating the top surface 100 and the bottom surface 102. The body 10 can be fabricated using injection molding or molding techniques using plastic or other polymeric materials. The body 10 can be black or other non-reflective dark material process to avoid reflection of the optical image generated by the object reflection by the body 10 to affect the imaging contrast. In other words, the base 10 is not recommended to be made of a material having a reflective effect such as white or silver.

The light source module 12 is configured to generate a linear light to illuminate the object. The light source module 12 includes a substrate 120, a light guiding rod 122, a reflecting member 124, and a plurality of light emitting diodes 126B, 126G, and 126R. The substrate 120 can be a printed circuit board or a flexible print circuit. The flexible circuit board can effectively reduce the volume and weight of the light source module 12.

The light guiding rod 122 can transmit light and include a light incident surface 1220 and a light emitting surface 1222. The light incident surface 1220 is configured to receive light generated by the light emitting diodes 126B, 126G, and 126R, and the light emitting surface 1222 is adjacent to the light incident surface 1220. And used to emit light.

The bottom surface of the light guiding rod 122 (not labeled) may form a plurality of microprisms 1226, such as to enable light entering the light guiding rod 122 from the light incident surface 1220 to be transmitted to the high beam side (ie, away from the light incident surface 1220); Adjacent to the light incident surface 1220 and opposite to the light exit surface 1222. The number of the microprisms 1226 is varied depending on the intensity of the light received by the placement position, and may vary, for example, in a non-linear manner; thereby, the uniform brightness of the linear light output from the light-emitting surface 1222 can be made.

More specifically, at a portion adjacent to the light incident surface 1220, the number of microprisms 1226 is low (i.e., low density) per unit area; at a distance from the light incident surface 1220, the microprisms 1226 are disposed per unit area. The number is high (ie, high density); in other words, the placement density of the microprism 1226 is inversely proportional to the intensity of the light received by its placement position.

The reflector 124 is disposed on the substrate 120 and includes a sidewall 1240 and a bottom wall 1242. The reflector 124 can be made of a color having a high reflective effect such as white or silver. The inner diameter of the sidewall 1240 increases as it moves away from the substrate 120, thereby changing the transmission path of the large-angle light generated by the LEDs 126B, 126G, and 126R, whereby the large-angle light can be smoothly coupled to the light guiding rod 122 to improve the light. The effect of utilization. The bottom wall 1242 is connected to one side of the side wall 1240 adjacent to the substrate 120 for carrying the light emitting diodes 126B, 126G, 126R.

The reflector 124 further includes a plurality of connectors 1244, one end of which may be disposed on the bottom wall 1242 and electrically connected to the LEDs 126B, 126G, 126R; the other end protrudes beyond the bottom wall 1242 for Electrical connection is made to the substrate 120.

Referring to FIG. 3, the LEDs 126B, 126G, and 126R are arranged along the first axis A on the bottom wall 1242, and the sidewalls 1240 surround the LEDs 126B, 126G, and 126R. The distance between the optical axis I of each of the light-emitting diodes 126B, 126G, and 126R and the first axis A is not more than 0.5 mm; wherein the optical axis C is the light emitted by each of the light-emitting diodes 126B, 126G, and 126R The axis of symmetry of the light intensity distribution in space.

The light-emitting diodes 126B, 126G, and 126R can respectively emit light at different time points; in the present creation, the light-emitting diode 126B is used to generate blue light having a wavelength of 450 to 480 nm, and the light-emitting diode 126G is used for generating a wavelength. In the green light of 508~555 nm, the light-emitting diode 126R is used to generate red light with a wavelength between 606 and 626 nm.

Referring to FIG. 4, after the light emitting body 126B, 126G, 126R and the light guiding rod 122 are assembled, the first axis A is parallel to one of the normal lines of the light emitting surface 1222; the light emitting diode 126R is arranged at the nearest light emitting surface 1222. The light-emitting diodes 126G are arranged next to the light-emitting surface 1222, and the light-emitting diodes 126B are arranged farthest from the light-emitting surface 1222; in other words, the light-emitting diodes 126G are arranged between the light-emitting diodes 126R and 126B. According to this, the image quality can be improved. In actual implementation, the relative positions of the LEDs 126B, 126G, and 126R and the light-emitting surface 1222 can be adjusted according to actual needs.

It should be particularly noted that the light-emitting diodes 126B, 126G, and 126R may be directly mounted on the substrate 120. In the foregoing state, the reflector 124 includes only the side wall 1240 for changing the transmission path of the large-angle light emitted from the light-emitting diodes 126B, 126G, 126R. In other words, when the light-emitting diodes 126B, 126G, 126R are directly mounted on the substrate 120, the reflector 124 may not include the bottom wall 1242 described above; accordingly, the overall length of the light source module 12 may be reduced.

The light source module 12 can also include a protection member 128 and a joint member 130. The protective member 128 partially covers the light guiding rod 122 and exposes at least the light incident surface 1220 and the light emitting surface 1222. The protective member 128 is mainly used for protecting the light guiding rod 122 to prevent the light guiding rod 122 from being broken due to no support during assembly or transportation. The protective member 128 can be made of a material having a reflective effect such as white or silver, and can reflect part of the light that is not emitted by the light-emitting surface 1222 of the light guiding rod 122, thereby improving the efficiency of light use.

One end of the engaging member 130 is provided with a reflector 124 and LEDs 126B, 126G, 126R. The light guiding rod 122 is disposed at the other end of the engaging member 130 to receive blue light generated by the LEDs 126B, 126G, and 126R. , green light, red light. In other words, the center of the engaging member 130 is provided with an opening of a suitable aperture (not shown) for the blue light, the green light, and the red light generated by the light-emitting diodes 126B, 126G, and 126R to be smoothly coupled to the light guiding rod 122. . In other words, the bonding member 130 can provide the effect of positioning the light guiding rod 122 and the LEDs 126B, 126G, and 126R and increasing the optical coupling ratio. The joint member 130 is further provided with a plurality of ribs 132 on one side surface of the accommodating light-emitting diodes 126B, 126G, and 126R, and the through holes 1200 formed in the substrate 120 are penetrated to achieve a positioning effect. Further, by controlling the timings of the blue light, the green light, and the red light generated by the light-emitting diodes 126B, 126G, and 126R, the light emitted from the light-emitting surface 1222 can be made visible to the human eye after being mixed.

Referring to FIG. 1 , the imaging module 14 is disposed in the through slot 106 for imaging an image of the object to the sensing module 16 . The imaging module 14 can include, for example, a complex refractive index progressive lens.

The sensing module 16 is disposed on one side of the base 10 and includes a circuit board 160 and a plurality of photosensitive members 162. The circuit board 160 can be, for example, but not limited to, a printed circuit board; the plurality of conductive portions 1202 on the substrate 120 can be electrically connected to the plurality of connection pads 164 on the circuit board 160 to illuminate the LEDs 126B, 126G, and 126R. Required power.

The photosensitive member 162 is arranged on the circuit board 160 along a second axis and is electrically connected to the circuit board 160. The angle θ between the optical axis of the photosensitive member 160 and the first axis A may be between 35 and 65 degrees ( As shown in FIG. 5, the photosensitive member 162 is arranged corresponding to the through groove 106 to receive the optical image generated by the object reflecting the light generated by the light source module 12, and further convert the optical image into an analog or digital electronic signal. The photosensitive member 162 may be a charge coupled device, a complementary metal oxide semiconductor device, or other element having photoelectric conversion characteristics.

The light-emitting diodes 126B, 126G, and 126R of the image capturing apparatus 1 of the present invention are appropriately positioned to increase the uniformity of the emitted light; and further, the light source module 12 is appropriately arranged to generate blue light, green light, and red light. The relative positions of the light-emitting diodes 126B, 126G, and 126R and the light-emitting surface 1222 are used to improve the image quality.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any person skilled in the art can make various changes and refinements without departing from the spirit and scope of the present creation. The scope is subject to the definition of the scope of the patent application.

1‧‧‧Image capture device

10‧‧‧ body

100‧‧‧ top surface

102‧‧‧ bottom

104‧‧‧ accommodating slots

106‧‧‧through slot

12‧‧‧Light source module

120‧‧‧Substrate

1200‧‧‧through holes

1202‧‧‧Electrical Department

122‧‧‧Light guide rod

1220‧‧‧Into the glossy surface

1222‧‧‧Glossy surface

1226‧‧‧Microprism

124‧‧‧Reflecting parts

1240‧‧‧ side wall

1242‧‧‧ bottom wall

126B, 126G, 126R‧‧‧Light Emitting Diodes

128‧‧‧protection

130‧‧‧Joint parts

132‧‧‧ ribs

14‧‧‧ imaging module

16‧‧‧Sensor module

160‧‧‧ boards

162‧‧‧Photosensitive parts

164‧‧‧Connecting mat

A‧‧‧first axis

C‧‧‧ optical axis

1 is an exploded perspective view of the image taking device according to the present invention;

2 is a partial exploded view of the image taking device according to the present invention;

3 is a top plan view of a substrate, a light reflecting member, and a light emitting diode according to the present invention;

4 is a perspective assembled view of a light source module according to the present invention;

Figure 5 is a cross-sectional view of the image taking device in accordance with the present invention.

12‧‧‧Light source module

120‧‧‧Substrate

1200‧‧‧through holes

122‧‧‧Light guide rod

1222‧‧‧Glossy surface

124‧‧‧Reflecting parts

126B, 126G, 126R‧‧‧Light Emitting Diodes

128‧‧‧protection

130‧‧‧Joint parts

132‧‧‧ ribs

A‧‧‧first axis

C‧‧‧ optical axis

Claims (9)

A light source module is applied to an image capturing device, the light source module comprises: a substrate; a light guiding rod having a light incident surface and a light exiting surface, the light emitting surface being adjacent to the light incident surface; and a plurality of light emitting diodes The light-emitting diodes are arranged along a first axis and project light toward the light-incident surface, and a distance between an optical axis of each of the light-emitting diodes and the first axis Not more than 0.5 mm, wherein the first axis is parallel to one of the normals of the light exit surface. The light source module of claim 1, wherein in the light emitting diodes, the light emitting diodes disposed closest to the light emitting surface are arranged to generate light having a wavelength of 606 to 626 nm, arranged in a row. The light-emitting diode adjacent to the light-emitting surface is configured to generate light having a wavelength of 508 to 555 nm, and the light-emitting diode disposed farthest from the light-emitting surface is used to generate light having a wavelength of 450 to 480 nm. The light source module of claim 1, wherein the light guiding rod comprises a plurality of microprisms formed on a bottom surface of the light guiding rod, the bottom surface is arranged relative to the light emitting surface, and the microprisms are arranged The density is inversely proportional to the intensity of the light received by its placement. The light source module of claim 1, further comprising a reflective member mounted on the substrate, a side wall of the reflective member surrounding the light emitting diodes, the inner diameter of the sidewall being away from the substrate increase. The light source module of claim 4, wherein the reflecting member further comprises a bottom wall connected to the side wall adjacent to one side of the substrate, and the light emitting diodes are disposed on the bottom wall. The light source module of claim 4, further comprising an engaging member, the light emitting diode and the reflecting member are disposed on one side of the engaging member, and the light guiding rod is mounted on the other side of the engaging member The white light generated by the combination of the light emitting diodes is received. The light source module of claim 1, further comprising a protective member partially covering the light guiding rod, the light incident surface and the light emitting surface being exposed outside the protective member. An image capturing device for capturing an image of an object, the image capturing device comprising: the light source module according to any one of items 1 to 7; a light source module is disposed in the receiving groove, the object is located on one side of the base; a sensing module is located on the other side of the base, and the sensing module includes a plurality of photosensitive members arranged in a second axis; an imaging module mounted in the through slot and configured to image an image of the object on the photosensitive members. The image capturing device of claim 8, wherein the first axis and the optical axis of the photosensitive member are at an angle of between 35 and 65 degrees.