JP2013157945A - Lighting device, lens and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for a lighting device and the like employing a bidirectional irradiation system with small light loss and high illuminance.SOLUTION: The lighting device comprises a light source and a lens. The lens comprises a first lens part and a second lens part. The first lens part condenses in a first direction a part of light emitted from the light source, and irradiates an irradiation target with condensed first condensation light. The second lens part condenses, in a second direction different from the first direction, another part of light emitted from the light source, and irradiates the irradiation target with condensed second condensation light via a reflection part from a direction different from that of the first condensation light.

Description

  The present technology relates to a technology such as an illumination device that divides light from a light source in different directions and irradiates light on an irradiation target such as a document from different directions.

  2. Description of the Related Art Conventionally, an irradiation apparatus for irradiating light to an irradiation object such as a document has been widely used in a copying machine, a scanner, a facsimile, or the like.

  For example, when the original is wrinkled, the original is a silky material, or a pasted original, a method of irradiating light on the original from one direction causes a shadow on the original. Due to the influence of the shadow, there arises a problem that the original cannot be accurately read and reproduced accurately. Therefore, there is a case where a method of irradiating light on a document from two different directions (hereinafter, this method is referred to as two-way irradiation) is used (see Patent Document 1 below).

  The illumination device described in Patent Document 1 includes a single light source, a light guide member that guides light, and a reflection member. A part of the light incident on the light guide member is not reflected inside the light guide member, but passes through the light guide member and is irradiated onto the document. Part of the light that has passed through the light guide member is repeatedly reflected inside the light guide member, then reflected by the reflective member, exits the light guide member, and is irradiated onto the document. As a result, the document can be irradiated with light from two different directions.

JP 2000-101788 A

  In the technique described in Patent Document 1, two-way irradiation is realized by a light guide member. However, the light guide member has a problem that the loss of light from the light source is large.

  In view of the circumstances as described above, an object of the present technology is to provide a technology such as a two-way irradiation type lighting device that has low light loss and high illuminance.

The illumination device according to the present technology includes a light source and a lens.
The lens includes a first lens unit and a second lens unit.
The first lens unit condenses a part of the emitted light from the light source in a first direction, and irradiates the irradiation target with the condensed first condensed light.
The second lens unit condenses another part of the light emitted from the light source in a second direction different from the first direction, and the condensed second condensed light is reflected by a reflection unit. Then, the irradiation object is irradiated from a direction different from that of the first condensed light.

  In the present technology, since the two-way irradiation method is realized by the lens, the loss of light emitted from the light source is small as compared with the case where the light guide member is used. Therefore, high illuminance can be obtained.

  In the illumination device, each of the first lens unit and the second lens unit is formed of a single plane or a combination of planes having different angles, and has an incident surface on which light emitted from the light source is incident. You may have.

  In the present technology, the entrance surface is formed by a single plane or a combination of planes having different angles, and thus the lens can be easily manufactured. In addition, the manufacturing cost of the lens can be reduced.

  In the illumination device, at least one of the incident surfaces of the first lens unit and the second lens unit may be formed in a convex shape.

  Thereby, the condensing effect | action of at least one can be improved among a 1st lens part and a 2nd lens part.

  In the illumination device, each of the first lens unit and the second lens unit may have a light exit surface formed in a spherical shape.

  Thus, by forming the light emission surface in a spherical shape (not an aspherical shape), the lens can be easily manufactured and the cost can be reduced.

  The illumination device may further include a substrate on which the light source is mounted. In this case, the lens may be mounted on the substrate so as to cover the light source.

  In the illumination device, the first lens unit and the second lens unit may be formed symmetrically with an emission direction of emission light of the light source as a boundary.

  In the illumination device, the first lens unit and the second lens unit may be formed asymmetrically with the emission direction of the emitted light of the light source as a boundary.

The lens according to the present technology includes a first lens unit and a second lens unit.
The first lens unit condenses a part of light emitted from the light source in the first direction, and irradiates the irradiation target with the condensed first condensed light.
The second lens unit condenses another part of the light emitted from the light source in a second direction different from the first direction, and the condensed second condensed light is reflected on the reflection unit. Then, the irradiation object is irradiated from a direction different from that of the first condensed light.

The electronic device according to the present technology includes a lighting device and a photoelectric conversion unit.
The lighting device includes a light source and a lens, and the lens includes a first lens unit and a second lens unit.
The first lens condenses a part of light emitted from the light source in a first direction and irradiates the irradiation target with the condensed first condensed light.
The second lens condenses another part of the emitted light from the light source in a second direction different from the first direction, and the condensed second condensed light is reflected through a reflecting portion. Thus, the irradiation object is irradiated from a direction different from that of the first condensed light.
The photoelectric conversion unit receives light reflected by the irradiation object and converts it into an electrical signal.

  As described above, according to the present technology, it is possible to provide a technology such as a two-way irradiation type lighting device with a small light loss and high illuminance.

It is a typical side view showing an illuminating device concerning one embodiment of this art. It is a typical expansion perspective view which shows the illumination module which an illuminating device has. It is a typical expanded side view which shows an illumination module. It is a figure for demonstrating a specific example about various values, such as the value of (theta) 1, and the value of (theta) 2. It is a figure which shows an example in case the entrance surface of a 1st lens part and the entrance surface of a 2nd lens part are formed by the aspherical surface.

  Hereinafter, embodiments according to the present technology will be described with reference to the drawings.

FIG. 1 is a schematic side view showing an illumination device 100 according to an embodiment of the present technology.
The illumination device 100 is used in electronic devices such as a copying machine, a scanner, and a facsimile, for example. The illumination device 100 includes the illumination module 10 and the reflection unit 20, and is disposed to face the irradiation object 30. The illumination module 10 includes a wiring board 11, a light source 12 mounted on the wiring board 11, and a lens 13 mounted on the wiring board 11.

  A photoelectric conversion element 40 as a photoelectric conversion unit is disposed at a position on the opposite side of the irradiation object 30 with the illumination device 100 interposed therebetween. As the photoelectric conversion element 40, for example, a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) device is used.

  The illumination device 100 (the illumination module 10 and the reflection unit 20) and the photoelectric conversion element 40 can be moved integrally in the sub-scanning direction (X-axis direction) by a moving mechanism (not shown).

  The irradiation object 30 is typically a manuscript, a book, a photograph, or the like. In addition, although illustration is abbreviate | omitted, the irradiation target object 30 is supported from the downward direction by the support member which consists of light transmissive materials, such as glass.

  FIG. 2 is a schematic enlarged perspective view showing the illumination module 10, and FIG. 3 is a schematic enlarged side view showing the illumination module 10.

  The wiring board 11 and the lens 13 are long in one direction and are provided so as to extend in the main scanning direction (Y′-axis direction). A plurality of light sources 12 are arranged on the wiring board 11 at predetermined intervals along the main scanning direction. The light source 12 is supplied with electric power from a wiring provided on the wiring board 11 and emits light at a necessary timing in accordance with control of a control unit (not shown).

  As the light source 12, an LED (Light Emitting Diode) is typically used. The lens 13 is typically formed of acrylic resin, but may be formed of glass or other transparent resin.

  The lens 13 is mounted on the wiring board 11 so as to cover the light source 12 with a space from the light source 12. The lens 13 includes a first lens unit 1, a second lens unit 2, and a connection unit 3. The connection portion 3 is bonded to the upper surface of the wiring board 11 with an adhesive or the like on the bottom surface side.

  The first lens unit 1 condenses a part of the emitted light from the light source 12 in the first direction D1, and irradiates the irradiation target 30 with the condensed first condensed light. The second lens unit 2 condenses another part of the light emitted from the light source 12 in a second direction D2 different from the first direction, and reflects the collected second condensed light. The irradiation object 30 is irradiated from a direction different from the first condensed light through the unit 20.

  The first lens unit 1 and the second lens unit 2 are formed symmetrically with the emission direction (Z′-axis direction) of the emitted light from the light source 12 as a boundary. Each of the first lens unit 1 and the second lens unit 2 has an incident surface 5 on which outgoing light from the light source 12 is incident and an outgoing surface 8 on which condensed light is emitted.

  The exit surface 8a of the first lens unit and the exit surface 8b of the second lens unit 2 are each formed in a spherical shape, not an aspherical surface. That is, the outer peripheral surface of the lens 13 is formed in a spherical shape. Thus, by forming the emission surface 8 with a spherical surface, the lens 13 can be easily manufactured, and the manufacturing cost can be reduced.

  The incident surface 5a of the first lens unit 1 and the incident surface 5b of the second lens unit 2 are each constituted by a plane, not an aspherical surface or a spherical surface. Thus, by forming the entrance surface 5 with a flat surface, the lens 13 can be easily manufactured, and the manufacturing cost can be reduced.

  In addition, the incident surfaces 5 of the first lens unit 1 and the second lens unit 2 are planar surfaces that form a predetermined angle with respect to the planar first incident surface 6 and the first incident surface 6, respectively. Second incident surface 7. The surfaces of the first lens unit 1 and the second lens unit 2 on the side facing the light source have a convex shape due to the combination of the two planar incident surfaces 6 and 7. Thus, the condensing effect | action of the 1st lens part 1 and the 2nd lens part 2 can be improved because the entrance plane 5 is made into convex shape.

  Here, since the LED as the light source 12 is a point light source, illuminance unevenness occurs in the main scanning direction (Y′-axis direction). Therefore, at least one of the entrance surface 5 and the exit surface 8 of the lens 13 may be subjected to prism processing, microlens processing, cylindrical lens processing, etc. for diffusing light in the main scanning direction. Thereby, unevenness in illuminance in the main scanning direction can be reduced.

  The movement of light will be described. First, light having a predetermined directivity is emitted upward (in the Z′-axis direction) from the light source 12. About half of the light emitted from the light source 12 is incident on the first incident surface 6 a and the second incident surface 7 a of the first lens unit 1. It is condensed in the direction D1. The remaining half of the light emitted from the light source 12 is incident on the first incident surface 6 b and the second incident surface 7 b of the second lens unit 2, and 2 is condensed in the direction D2. That is, the emitted light from the light source 12 is divided and condensed in two directions (D1 and D2) by the first lens unit 1 and the second lens unit 2 in the sub-scanning direction (X′-axis direction). .

  The first condensed light condensed in the first direction D1 by the first lens unit 1 is emitted from the emission surface 8a of the first lens unit 1 and directly irradiated to the irradiation object 30. . On the other hand, after the second condensed light collected in the second direction D2 by the second lens unit 2 is emitted from the emission surface 8b of the second lens unit 2 and reflected by the reflecting unit 20, The irradiation object 30 is irradiated from a direction different from the first condensed light.

  The illumination device 100 irradiates condensed light from two different directions in the sub-scanning direction to the irradiation object 30 while being moved in the sub-scanning direction (X-axis direction (FIG. 1)). Thereby, light is irradiated to the whole irradiation object 30. The photoelectric conversion element 40 receives the light reflected by the irradiation object 30 while being moved in the sub-scanning direction (X-axis direction) integrally with the illuminating device 100 and converts it into an electrical signal. Thereby, the photoelectric conversion element 40 can generate an electrical signal corresponding to the entire image information of the irradiation object 30.

  Since the illumination device 100 according to the present technology is a two-way irradiation method, even when the irradiation target 30 such as a manuscript, a book, or a photograph is wrinkled, or when these materials are silky, The influence of can be eliminated. That is, the electronic device can accurately read the irradiation object 30 such as a document by the photoelectric conversion element 40 and reproduce it cleanly.

  Moreover, since the illuminating device 100 which concerns on this embodiment has implement | achieved the system of 2 directions irradiation with the lens 13, compared with the case where a light guide member is used, there is little loss of the light radiate | emitted from the light source 12. FIG. Therefore, high illuminance can be obtained.

  Furthermore, when a light guide member is used, the light guide member tends to be relatively large because the light path needs to be lengthened to eliminate unevenness of the light source 12, and the lighting device 100 (illumination module 10) There is a problem that miniaturization is difficult. On the other hand, since the illumination device 100 according to the present embodiment realizes a two-way irradiation method by the lens 13, it can be easily downsized as compared with the case where a light guide member is used.

  Here, referring to FIG. 3, the light collection range A1 and the light emission angle θ3 of the condensed light are the perpendicular line extending from the light source 12 and the angle θ1 of the first incident surface 6, and the first incident surface 6 and the first incident surface 6. The angle θ2 of the incident surface 7 and the curvature R of the exit surface 8 can be changed as appropriate. For example, if the angle θ1 of the perpendicular extending from the light source 12 and the first incident surface 6 is reduced (acute), the emission angle θ3 is increased, and conversely, if θ1 is increased (obtuse), the emission angle θ3 is reduced. Become. Further, for example, when the angle θ2 of the first incident surface 6 and the second incident surface 7 is narrowed (acute), the condensing range A is widened, and conversely, when θ2 is widened (obtuse), the condensing range. A becomes narrower.

  By changing the various values described above, it is possible to appropriately cope with positional constraints inside the electronic device and optical specification conditions. Further, by making the above-described various values different between the first lens unit 1 and the second lens unit 2, the illuminance with which the first condensed light illuminates the irradiation object 30 and the second condensed light. The ratio with the illuminance at which light illuminates the irradiation object 30 can be changed. That is, by making the first lens unit 1 and the second lens unit 2 asymmetric with respect to the emission direction (Z′-axis direction) of the emitted light from the light source 12, the first condensed light is irradiated. The ratio between the illuminance that illuminates 30 and the illuminance that the second condensed light illuminates the irradiation object 30 can be changed.

  For example, since the second condensed light has a longer optical path length than the first condensed light, the illuminance at which the second condensed light illuminates the irradiation object 30 is the irradiation intensity of the first condensed light. It tends to be lower than the illuminance illuminating the object 30. Therefore, the various values of the first lens unit 1 and the various values of the second lens unit 2 are made different (that is, the first lens unit 1 and the second lens unit 2 are asymmetric). The ratio of the illuminance by the first condensed light and the illuminance by the second condensed light may be the same. In this case, if the values of θ1 and θ2 are made different between the first lens unit 1 and the second lens unit 2, the lens 13 can be manufactured easily.

[Specific example]
Next, specific examples of various values such as θ1 and θ2 when the illumination device 100 is applied to a copying machine will be described.

  FIG. 4 is a diagram for explaining a specific example of various values such as the value of θ1 and the value of θ2.

  For example, as the light source 12 (LED), a light source 12 having a size of 1.6 × 3.2 (mm) and directivity of 120 degrees (50% light amount) is used. The lens 13 is made of polymethyl methacrylate resin (PMMA), transmittance of 87% (wavelength: 380 nm to 760 nm), refractive index of 1.4918 (wavelength: 587.6 nm), and critical angle. A lens 13 having an angle of 42 degrees is used.

  In this case, the angle θ1 between the perpendicular extending from the light source 12 and the first incident surface 6 is 30 °, and the angle θ2 between the first incident surface 6 and the second incident surface 7 is 160.8 °. It is said. Further, the distance d1 from the light source 12 to the irradiation object 30 is 15.16 mm, and the distance in the X-axis direction from the light source 12 to the reflection unit 20 is 16.94 mm.

  The example shown here is only an example, and the present technology is not limited to this.

[Variations]
In the example described above, the incident surfaces 5 of the first lens unit 1 and the second lens unit 2 have a predetermined angle with respect to the planar first incident surface 6 and the first incident surface 6, respectively. The case where it is formed by the planar second incident surface 7 formed has been described. On the other hand, at least one of the incident surface 5a of the first lens unit 1 and the incident surface 5b of the second lens unit 2 may be formed by a single plane (in this case, the incident surface 5 is a light source). It does not have a convex shape toward the 12 side).

  In the above-described example, the emission surfaces 8 of the first lens unit 1 and the second lens unit 2 are formed in a spherical shape. On the other hand, at least one of the emission surface 8a of the first lens unit 1 and the emission surface 8a of the second lens unit 2 may be formed of an aspherical surface. Similarly, at least one of the incident surface 5a of the first lens unit 1 and the incident surface 5b of the second lens unit 2 may be formed of an aspherical surface.

  FIG. 5 shows an example in which the incident surface 5 of the first lens unit 1 and the incident surface 5 of the second lens unit 2 are formed of aspherical surfaces. As shown in FIG. 5, the first lens unit 1 has an aspherical incident surface 9a, and the second lens unit 2 has an aspherical incident surface 9b. About another point, it is the same as that of the above-mentioned example.

This technique can also take the following composition.
(1) a light source;
A first lens unit for condensing a part of the emitted light from the light source in a first direction and irradiating the irradiated object with the condensed first condensed light, and the emitted light from the light source The other part is condensed in a second direction different from the first direction, and the condensed second condensed light is irradiated from a direction different from the first condensed light through the reflecting portion. A lighting device comprising: a lens having a second lens portion that irradiates an object.
(2) The lighting device according to (1) above,
The first lens unit and the second lens unit each have an incident surface that is formed by a combination of a single plane or planes having different angles, on which light emitted from the light source is incident.
(3) The illumination device according to (2) above,
Of the incident surface of the first lens unit and the incident surface of the second lens unit, at least one incident surface is formed in a convex shape. (4) Any one of (1) to (3) A lighting device according to claim 1,
The first lens unit and the second lens unit each have a light emission surface formed in a spherical shape.
(5) The illumination device according to any one of (1) to (4),
A substrate on which the light source is mounted;
The lens is mounted on the substrate so as to cover the light source.
(6) The illumination device according to any one of (1) to (5) above,
The first lens unit and the second lens unit are formed symmetrically with an emission direction of emitted light of the light source as a boundary.
(7) The illumination device according to any one of (1) to (5),
The first lens unit and the second lens unit are formed asymmetrically with an emission direction of emitted light of the light source as a boundary.
(8) a first lens unit that condenses a part of the emitted light from the light source in the first direction and irradiates the irradiation target with the collected first condensed light;
The other part of the emitted light from the light source is condensed in a second direction different from the first direction, and the condensed second condensed light is first condensed through the reflecting portion. A lens (9) comprising: a second lens unit that irradiates the irradiation object from a direction different from the light; and a part of the light emitted from the light source in the first direction. The first lens unit for irradiating the irradiation target with the first condensed light and the other part of the light emitted from the light source are condensed in a second direction different from the first direction to collect the light. A lens including a second lens unit that irradiates the irradiation target object with the second condensed light that has been applied to the irradiation object from a direction different from the first condensed light through the reflection unit;
An electronic device comprising: a photoelectric conversion unit that receives light reflected by the irradiation object and converts the light into an electrical signal.

D1 ... 1st direction D2 ... 2nd direction 1 ... 1st lens part 2 ... 2nd lens part 5, 9 ... Incident surface 6 ... 1st incident surface 7 ... 2nd incident surface 8 ... Output surface DESCRIPTION OF SYMBOLS 10 ... Illumination module 11 ... Wiring board 12 ... Light source 13 ... Lens 20 ... Reflection part 30 ... Irradiation target 40 ... Photoelectric conversion element 100 ... Illumination device

Claims (9)

A light source;
A first lens unit for condensing a part of the emitted light from the light source in a first direction and irradiating the irradiated object with the condensed first condensed light, and the emitted light from the light source The other part is condensed in a second direction different from the first direction, and the condensed second condensed light is irradiated from a direction different from the first condensed light through the reflecting portion. A lighting device comprising: a lens having a second lens portion that irradiates an object. The lighting device according to claim 1,
The first lens unit and the second lens unit each have an incident surface that is formed by a combination of a single plane or planes having different angles, on which light emitted from the light source is incident. The lighting device according to claim 2,
Of the incident surface of the first lens unit and the incident surface of the second lens unit, at least one incident surface is formed in a convex shape. The lighting device according to claim 1,
The first lens unit and the second lens unit each have a light emission surface formed in a spherical shape. The lighting device according to claim 1,
A substrate on which the light source is mounted;
The lens is mounted on the substrate so as to cover the light source. The lighting device according to claim 1,
The first lens unit and the second lens unit are formed symmetrically with an emission direction of emitted light of the light source as a boundary. The lighting device according to claim 1,
The first lens unit and the second lens unit are formed asymmetrically with an emission direction of emitted light of the light source as a boundary. A first lens unit that condenses a part of the light emitted from the light source in a first direction and irradiates the irradiation target with the collected first condensed light;
The other part of the emitted light from the light source is condensed in a second direction different from the first direction, and the condensed second condensed light is first condensed through the reflecting portion. A second lens unit that irradiates the irradiation object from a direction different from that of the light. A first light source, a first lens part for condensing a part of the light emitted from the light source in a first direction, and irradiating the irradiated first condensed light on the object to be irradiated; The other part of the emitted light is condensed in a second direction different from the first direction, and the collected second condensed light is different from the first condensed light via the reflecting portion. A lighting device having a lens including a second lens unit that irradiates an irradiation object from a direction;
An electronic device comprising: a photoelectric conversion unit that receives light reflected by the irradiation object and converts the light into an electrical signal.

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