CN203571527U - Linear light source - Google Patents

Abstract

The utility model discloses a linear light source for image sensing modules, which includes a light guide element, a reflective cavity and at least one light source. The light guide element is provided with at least one incident surface and a single side surface. The side has a light scattering structure; the light source is arranged on the incident surface of the end of the light guide element and emits light toward the inside of the light guide element. When the light source emits light, the light enters the light guide element and travels inside the light guide element through total reflection of light on the side of the light guide element. When the light reaches the scattering structure, the total reflection phenomenon is destroyed, causing the light to scatter. Leave the light guide element; the reflective cavity is provided with at least one light inlet opening and at least one light outlet opening, the inside of the reflective cavity is a light reflective surface, and the light guide element is placed in the reflective cavity. The linear light source can form a straight-line or U-shaped curve illumination distribution through the light scattering structure design in the axial direction of the light guide element. In this way, the image of the illuminated object can be converted by the image sensing module to form a uniform image signal.

Description

linear light source

technical field

This creation is about a linear light source for image sensing modules, especially a linear light source that can generate a predetermined illumination distribution and form a complementary effect on imaging lenses and image sensors, and is used in fax machines, printing Meters, scanners and multi-function business machines. the

Background technique

Devices or products that need to record or detect images in the market include scanners, multi-function machines (MFPs), digital photocopiers, ATM currency detectors, traveler's check inspection machines, ballot inspection machines, and the optics of list machines. Modules, card readers, optical identification readers, barcode identification, fax machines, etc., but these products all require scanning and reading modules. the

At present, scanning and reading modules are mainly divided into two mainstream architectures: CCD (Charge Couple Device) and CIS (Contact Image Sensor). No matter which architecture includes light source module, optical lens module, image sensor chip module and Kinematics mod. When the light from the light source module is projected on the document, the light with information is reflected by the document, and then enters the optical lens module to be imaged on the image sensor, and finally the optical signal is converted into an electronic signal by the image sensor. the

Early light source modules used fluorescent tubes as light sources, such as cold cathode fluorescent lamps (CCFL; Cold Cathode Fluorescent Lamp), halogen lamps, etc., but because cold cathode fluorescent tubes require additional voltage converters and contain halogen And fluorescent powder does not meet the increasingly stringent environmental protection requirements. Light Emitting Diode (LED; Light Emitting Diode) has the advantages of power saving, high luminous efficiency and long life, and has been gradually used in scanning light source modules in recent years. In addition, an LED array is arranged at the rear end of the lenticular mirror, so that the illumination distribution on the document can be evenly applied to the scanner. the

For the design of CIS architecture, it is expected that the light source module can emit linear light with uniform illumination. For example, Taiwan patent TW579640 discloses the light collection structure of different scanners. It uses light collection elements and light guide elements to guide the light emitted by the light source to the scanning on the file. As shown in Fig. 1, Taiwan patent TW158740 discloses a linear illuminator. The light source 1 is placed at one end of a rod-shaped light guide column 2, and the astigmatism pattern 3 is set on the focal area of a curved surface 4 shaped like a concave mirror. Reflected by the curved surface 4 and emitted from a plane, the reflected light 5 is focused on a predetermined focal point 6 . If the predetermined focus position is aligned with an image surface to be read, the light scattered by the astigmatism pattern will completely shine on the image surface without wasting, so the spatial distribution of light intensity in the sub-scanning direction can be be homogenized. the

However, due to the influence of the focusing surface of the optical lens of the imaging lens on the design of the CCD structure, after the light reflected at the edge of the document ends enters the imaging lens and is focused by the imaging lens, the light emitted from the edge of the imaging lens The intensity is relatively weak, so that the intensity of light received by the two ends of the CCD is relatively weak; this will cause the edge of the document image to be dark. Therefore, the CCD structure needs to provide a U-shaped illuminance distribution by the light source module instead. As shown in Fig. 2, US20050195452 proposes a way to control the brightness of each LED by arranging an LED array 8 at the rear end of the light guide 7, so that the illuminance of the emitted light on the document 9 to be scanned can be uniform or uniform. Form a U-shaped illumination distribution to replace CCFL in high-speed scanners. However, adopting technical means such as using the LED array 8 at the rear end of the light guide body 7 requires many single LEDs and complicated control. the

Another technical solution is to install the light source on the end face of the light guide, and set an end cover at the light emitting end to prevent most of the light from escaping from the end face, and set a toothed reflective surface on the polygonal light guide. In order to fully reflect the light emitted by the light source to increase the utilization of the light, and to adjust the light pattern after the light is emitted by using different tooth shapes and tooth spacing. the

Utility model content

This creation proposes a linear light source, which is characterized in that its main structure includes: a light-reflecting cavity, a light-guiding element, and at least one light-emitting source. The reflective cavity is provided with at least one light entrance opening and at least one light exit opening, and the inner wall of the light reflective cavity is a light reflection surface; the light guide element is arranged in the light reflective cavity, and the light guide element is a columnar structure, including at least one light incident A surface and a side surface, wherein the side surface has a light-scattering structure with a pinnate rib, and the light that enters the light-guiding element is scattered out of the light-guiding element by using the light-scattering structure; and at least one light source, at least one light source is arranged on The incident surface of the end of the light guide element. In an embodiment of the present invention, the cross-sectional shape of the light guide element in the long axis direction is formed by combining two curved surfaces with different curvatures. the

In an embodiment of the invention, the light scattering structure of the pinnate ribs is a plurality of pinnate ribs connected side by side. the

In an embodiment of the present invention, the section of the above-mentioned feather tooth rib is polyhedral or arc-shaped. the

In an embodiment of the invention, the cross section of the above-mentioned feather-shaped tooth ribs is a concave or convex structure. the

In an embodiment of the present invention, the cross-sectional shape of the above-mentioned light guide element in the long axis direction is a single smooth curve shape that can be differentiated once. the

In an embodiment of the present invention, the cross-sectional shape of the above-mentioned light guide element in the direction of the long axis is a perfect circle or an ellipse. the

In an embodiment of the invention, the above-mentioned light incident surface is a plane, a curved surface or a polyhedron structure. the

In an embodiment of the present invention, the above light source may be a light emitting diode or an organic light emitting diode. the

This creation proposes a linear light source, which is characterized in that its main structure includes: a light-reflecting cavity, a light-guiding element, and two light-emitting sources. The reflective cavity is provided with two light-incoming openings and at least one light-emitting opening, and the inner wall of the reflective cavity is a light-reflecting surface; the light-guiding element is arranged in the light-reflecting cavity, and the light-guiding element is a columnar structure, including at least two light-incident surfaces and a side surface, wherein, the side surface has a light-scattering structure with a feather-shaped tooth rib, and the light that enters the light-guiding element is scattered out of the light-guiding element by using the light-scattering structure; and two light sources, these light-emitting sources are arranged on the light-guiding element The light incident surface of the two ends. the

In an embodiment of the present invention, the cross-sectional shape of the light guide element in the long axis direction is formed by combining two curved surfaces with different curvatures. the

In an embodiment of the invention, the light scattering structure of the pinnate ribs is a plurality of pinnate ribs connected side by side. the

In an embodiment of the present invention, the section of the above-mentioned feather tooth rib is polyhedral or arc-shaped. the

In an embodiment of the invention, the cross section of the above-mentioned feather-shaped tooth ribs is a concave or convex structure. the

The above overview and the following embodiments are all to further illustrate the technical means and achieved effects of this creation, but the described embodiments and drawings are only for reference and description, and are not used to limit this creation. the

Description of drawings

FIG. 1 is a schematic diagram of a conventional linear light source applied to an image scanning module. the

FIG. 2 is a schematic diagram of another conventional linear light source applied to an image scanning module. the

Fig. 3 is a schematic diagram of the first embodiment of the linear light source of the light guide body with pinnate ribs created for the present invention. the

Fig. 4 is the single side of the light guide element of the linear light source created for this invention is a light scattering structure schematic diagram with a pinnate tooth rib. the

FIG. 5 is a schematic diagram of a second embodiment of a linear light source with a light guide body having feather-shaped ribs according to the present invention. the

Fig. 6 is a schematic diagram of different embodiments of pinnate tooth ribs of the light guide element of the linear light source of the present invention. the

【Symbol Description】

1 light source

2 rod-shaped light guide column

3 astigmatism pattern

4 Surface of concave mirror

5 Reflected light emitted from the plane

6 focus position

7 light guide body

8 LED Array

9 Documents to be scanned

10 linear light source

20 light guide element

21, 21a, 21b Incident surface of the light guide element

22 Single side of the light guide element

23 Light scattering structure of light guide element

30 reflective cavity

31 Light entrance opening of reflective cavity

32 The light exit opening of the reflective cavity

40, 41 Light-emitting diodes

50 rays

Detailed ways

Embodiments of the linear light source for the image sensing module according to the present invention will be described below with reference to related drawings. For ease of understanding, the same components in the following embodiments are described with the same symbols. the

The purpose of this creation is to propose a linear light source 10 for an image sensing module, which is a light source module applied to a CIS or CCD image sensor. The linear light source 10 includes a light guide element 20 and a light reflecting cavity 30 And at least one light source 1; wherein, the light guide element 20 is made of optical material, is provided with at least one incident surface 21 of the light guide element and a single side 22 of the light guide element, and the single side 22 of the light guide element has A light-scattering structure 23 of the light-guide element with a pinnate rib; the light source 1 is disposed on the incident surface 21 of the light-guide element at the end of the light-guide element 20 and emits light toward the inside of the light-guide element 20 . After the light emitting source 1 emits light, the light enters the light guide element 20 and travels inside the light guide element 20 through the side of the light guide element 20 in a way of total reflection. When the light reaches the light scattering structure 23 of the light guide element Due to the destruction of its total reflection phenomenon, the light scatters and leaves the light guide element 20; the light-reflecting cavity 30 is provided with at least one light-entrance opening 31 of the light-reflecting cavity and at least one light-emitting opening 32 of the light-reflecting cavity, and the interior of the reflective cavity 30 is light reflective surface, and the light guide element 20 is placed in the reflective cavity 30, so the scattered light caused by the scattering structure is reflected by the light reflection surface of the reflective cavity 30, and finally emitted from the light outlet opening 32 of the reflective cavity for irradiation On the document to be scanned, the linear light source 10 can form a straight or U-shaped illuminance distribution in the axial direction of the light guide element 20 through the design of the light scattering structure 23 of the light guide element. In this way, the image of the object to be illuminated can be converted by the image sensing module to form a uniform image signal. the

According to the purpose of this creation, the side of the light guide element 20 can be viewed from the radial section of the light guide element 20 as a perfect circle, ellipse, etc., a single smooth side that can be differentiated at one time, rather than polygonal or multiple curved surfaces. The combined cross-sectional shape makes it have the light-gathering effect of the lens, reduces light scatter, and improves the average illuminance on the exit surface of the light guide. In addition, the purpose of this creation is to have a light scattering structure 23 of the light guide element with a feather-shaped rib on the single side 22 of the light guide element, so as to further improve the smoothness of the light illuminance emitted by the light guide element 20 . the

Based on the above, because of the linear light source 10 used for the image sensing module according to the invention, it can have one or more of the following advantages: (1) light scattering by the light guide element of the feather-shaped tooth rib proposed in the invention The light guide element 20 with the structure 23 increases the fluidity of the optical material in the rib portion during the injection process, so that the optical material can be more completely filled in the rib structure, which can improve the disadvantages of high cost and complicated control of the conventional injection process. (2) According to this creation, the single side 22 of the light guide element is a perfect circle, ellipse, etc. The light guide element 20 can form the illuminance distribution of the lens light concentrating effect in the radial direction of the light guide element 20, and in the axial direction Forming a straight or U-shaped illuminance distribution can complement CIS or CCD to generate image signals with uniform light intensity and meet the needs of high-resolution and high-speed scanning. the

Please refer to FIG. 3 , which is a schematic diagram of a first embodiment of a linear light source for an image sensing module in this invention. Please refer to Figure 4, which is a schematic diagram of a light-scattering structure with a feather-like tooth rib on a single side of the light-guiding element of the linear light source. The linear light source 10 includes a light-guiding element 20, a light-reflecting cavity 30, and at least one light-emitting diode 40; wherein, the light-guiding element 20 is a rod-shaped structure made of optical material with a perfect circular cross-section, and is provided with an incident surface 21 and A single side 22; a light-emitting diode 40 is disposed on the incident surface 21 of the light guide element and emits light toward the interior of the light guide element. When the light emitting diode 40 emits light 50, the light 50 enters the light guide element 20. Since the refractive index of the light guide element 20 is greater than the refractive index of air 1.0, when the light emitting diode emits light, the light passes through The end incident surface 21 enters the light guide element 20. Since the refractive index of the light guide element 20 is greater than the refractive index of air 1.0, the light entering the light guide element 20 will only be refracted within the critical angle and will not pass through the light guide. Component 20; the light 50 travels inside the light guide component 20 by means of total reflection on the single side 22 of the light guide component. When the light 50 reaches the light scattering structure 23 of the light guide component, the total reflection phenomenon of the light 50 is destroyed. Scattered away from the light guide element 20; the reflective cavity 30 is provided with at least one light entrance opening 31 and at least one light exit opening 32, the interior of the light reflective cavity is a light reflection surface, and the light guide element 20 is placed in the reflective cavity 30, Therefore, the scattered light caused by the light scattering structure 23 of the light guide element reflects the light 50 through the light reflection surface of the light-reflecting cavity, and finally emits the light 50 from the light-emitting opening 32 of the light-reflecting cavity to irradiate the document to be scanned. the

Further, the light-scattering structure of the feather-shaped tooth ribs is that each tooth rib is connected to each other, and the advantage is that part of the scattered light 50 passes through the light-reflecting surface of the light-reflecting cavity when the light 50 is reflected in the axial direction (x direction) of the light-guiding element. The tooth ribs also scatter the light 50 again to form bright lines, and have a smoother distribution of illumination in the axial direction (z direction). In addition, the fluidity of the optical material in the tooth rib part is increased in the injection process, so that the optical material can be more completely Filling the tooth rib structure can improve the disadvantages of high cost and complicated control of the conventional injection process. the

Furthermore, in the scanning direction (x direction), since the cross-section of the light guide element is a perfect circle, ellipse, etc. structure, it can provide the image scanner with the illuminance distribution that forms the light-gathering effect of the lens. In order to achieve the best effect, the radius of curvature of the light guide element 20 and the distance to the document to be scanned can be matched with each other. the

Please refer to FIG. 5 , which is a schematic diagram of a second embodiment of a linear light source for an image sensing module in this invention. In this embodiment, the light guide element 20 is an optical material polymethyl methacrylate (PMMA) made of a rod-shaped structure with an elliptical cross-section and has an incident surface 21a and an incident surface 21b at the ends. and respectively correspond to the left light emitting diode 40 and the right light emitting diode 41; wherein, when the left light emitting diode 40 and the right light emitting diode 41 emit light 50, the light 50 enters the light guide element 20, due to the light guide The refractive index nd of the element 20 is greater than the refractive index of air 1.0, and the light 50 travels inside the light guide element 20 through the single side 22 of the light guide element in a way of total reflection of light. When the light 50 reaches the light scattering structure of the light guide element At 23 o'clock, due to the destruction of its total reflection phenomenon, the light 50 scatters and leaves the light guide element 20; the interior of the light-reflecting cavity 30 is a light reflection surface, and the light-guiding element 20 is placed in the light-reflecting cavity 30, so the light from the light-guiding element The scattering structure 23 causes the scattered light to reflect the light 50 through the light reflection surface of the reflective cavity, and finally the light 50 is emitted from the light outlet opening 32 of the reflective cavity to irradiate the document to be scanned. the

Please refer to Fig. 6, which is a schematic diagram of different pinnate tooth rib embodiments of the light guide element of the linear light source created in this invention, wherein each tooth rib is all connected to each other, but the tooth ribs can be arranged in different sizes and intervals according to the position; in addition, the tooth ribs The cross-section of the rib can be polyhedral or arc-shaped such as corner column, column, trapezoidal column, etc., or the tooth rib can be a concave or convex structure. the

To sum up the above, the function of the linear light source used in the image sensing module of this invention lies in that the light guide element with the light-scattering structure of the pinnate ribs and the light source arranged on the incident surface at the end of the light guide element can be axially The direction (z direction) forms a straight or U-shaped illuminance distribution, while the scanning direction (x direction) forms a linear and concentrated illuminance distribution, which can be used for high-resolution and high-speed scanners. the

The above descriptions are illustrative only, not restrictive. Any equivalent modification or change that does not deviate from the spirit and scope of this creation shall be included in the scope of the attached patent application. the

Claims (14)

1. a linear light sorurce, is characterized in that, its primary structure system comprises:

One reflective cavity volume, this reflective cavity volume is provided with at least one light inlet opening and at least one bright dipping opening, and the inwall of this reflective cavity volume is a light reflection surface;

One light-guide device, is disposed in this reflective cavity volume, and this light-guide device is column structure, comprise at least one light entrance face and a side, wherein, this side has the light scattering structure of a pinniform tooth rib, utilizes this light scattering structure that the light scattering of injecting this light-guide device is gone out to this light-guide device; And

At least one light emitting source, this at least one light emitting source is the plane of incidence that is arranged at the end of this light-guide device.

2. linear light sorurce as claimed in claim 1, is characterized in that, the section shape of the long axis direction of this light-guide device is that the curved surface of two different curvature is combined into.

3. linear light sorurce as claimed in claim 1, is characterized in that, the light scattering structure of this pinniform tooth rib is that a plurality of pinniform tooth ribs are connected side by side.

4. linear light sorurce as claimed in claim 1, is characterized in that, this pinniform tooth rib section is Polyhedral or arcuate shape.

5. linear light sorurce as claimed in claim 1, is characterized in that, this pinniform tooth rib section is depression or bulge-structure.

6. linear light sorurce as claimed in claim 1, is characterized in that, the section shape of the long axis direction of this light-guide device is differentiable single smooth, curvilinear shape once.

7. linear light sorurce as claimed in claim 6, is characterized in that, the section shape of the long axis direction of this light-guide device is just circle or elliptical shape.

8. linear light sorurce as claimed in claim 1, is characterized in that, this light entrance face is plane, curved surface or polyhedral structure.

9. linear light sorurce as claimed in claim 1, is characterized in that, this light emitting source is light-emittingdiode or organic light emitting diode.

10. a linear light sorurce, is characterized in that, its primary structure system comprises:

One reflective cavity volume, this reflective cavity volume is provided with two light inlet openings and at least one bright dipping opening, and the inwall of this reflective cavity volume is a light reflection surface;

One light-guide device, is disposed in reflective cavity volume, and this light-guide device is column structure, comprise at least two light entrance faces and a side, wherein, this side has the light scattering structure of a pinniform tooth rib, utilizes this light scattering structure that the light scattering of injecting this light-guide device is gone out to this light-guide device; And

Two light emitting sources, those light emitting sources are arranged at the light entrance face of two ends of this light-guide device.

11. linear light sorurces as claimed in claim 10, is characterized in that, the section shape of the long axis direction of this light-guide device is that the curved surface of two different curvature is combined into.

12. linear light sorurces as claimed in claim 10, is characterized in that, the light scattering structure of this pinniform tooth rib is that a plurality of pinniform tooth ribs are connected side by side.

13. linear light sorurces as claimed in claim 10, is characterized in that, the section of this pinniform tooth rib is Polyhedral or arcuate shape.

14. linear light sorurces as claimed in claim 10, is characterized in that, the section of this pinniform tooth rib is depression or bulge-structure.

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