JP3575515B2 - scanner - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a scanner, and more particularly, to a small-sized scanner having a reflection optical member for forming an optical path between a document and a lens in order to secure a required conjugate length.
[0002]
[Prior art]
In a handy scanner that illuminates a document with a light source for illumination and captures image information while moving along the document, a light from a document surface incident from a reading opening (slit) is input through a lens to a line sensor (CCD). Leading to. Conventionally, in order to secure such a conjugate length, a plurality of folding mirrors are provided in the casing of the scanner.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional scanner, the adjustment of the angle of the mirror provided to secure a necessary conjugate length is delicate, and it is extremely difficult to assemble a plurality of mirrors at an appropriate angle.
Further, when the number of times of folding is increased, the number of mirrors is increased, and it is difficult to further reduce the size.
[0004]
The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a scanner that can be easily assembled and can be further reduced in size.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention illuminates the original surface with a light source for illumination and is moved along the original surface, guides light from the original surface to a line sensor through a lens, and In a scanner for reading image information, two sets of parallel planes having different lengths are provided, and light from the document surface incident on a medium region surrounded by the two sets of parallel planes is reflected on each of the parallel planes. A reflection optical member for forming an optical path that reflects at least once and emits toward the lens; and a movement position detection unit for detecting a relative movement amount between the scanner and the document surface; The reflecting optical member is arranged to be inclined with respect to the direction of the incident optical axis of light from the document surface, and the illumination light source and the light source are arranged in a space formed between the lower surface of the reflecting optical member and the document surface. Moving position detecting means is provided on the original surface It is characterized by being disposed respectively on the left and right sides of the optical axis of incidence al light.
[0006]
According to the present invention, light incident on a reflecting optical member having two sets of parallel planes having different lengths as reflecting surfaces is reflected at least once on each surface of the parallel plane, and is emitted from the reflecting optical member. . As described above, a relatively long optical path length can be formed by turning the light path back at the four reflective surfaces inside the reflective optical member. If such a reflection optical member is used, fine angle adjustment of the reflection surface becomes unnecessary or easy, and the size can be further reduced.
[0007]
The reflecting optical member includes a pair of parallel reflecting surfaces on the short side and a pair of parallel reflecting surfaces on the long side. The reflecting optical member is inclined with respect to the incident optical axis of light from the document surface. With this arrangement, a space defined by the lower surface of the reflective optical member and the document surface is formed below the reflective optical member. By arranging the light source for illumination and the moving position detecting means on the left and right sides of the incident optical axis in this space, the distance between the light source and the moving position detecting means can be relatively short, and the scanner can be made thinner. In addition, the size can be reduced.
[0008]
For example, in a rectangular optical member in which two sets of parallel planes having different lengths form 90 degrees with each other, they are arranged at an angle of about 30 degrees or about 45 degrees with respect to the direction of the incident optical axis of light from the document surface. .
Further, since the moving position detecting means generally occupies a larger space than the illumination light source, the illumination light source is arranged below the short-side reflection surface of the lower reflection surface of the reflection optical member. Further, by disposing the movement position detecting means below the long-side reflection surface, further downsizing can be achieved.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the scanner according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a side perspective view of a handy scanner to which the present invention is applied, and FIG. 2 is a front perspective view.
[0010]
The scanner 10 shown in FIG. 1 includes a light source 14 for illumination, a prism block (corresponding to a reflective optical member) 16, a lens 18, a line sensor (CCD) 20, a scanner circuit 22, a roller 24 for position detection, and the like inside a casing 12. Is arranged. Incidentally, reference numeral 26 in the drawing denotes a CCD substrate.
The light source 14 is disposed at the bottom of the casing 12 at the lower left corner in FIG. 1, and a prism block 16 is disposed adjacent to the right side of the light source 14. A slit 28 is formed in the bottom surface of the casing 12 and directly below the prism block 16. Illumination light of the light source 14 is irradiated on the original 30 through the slit 28, and light from the original 30 is transmitted to the casing 12. It is designed to be taken in.
[0011]
The prism block 16 is formed of transparent optical plastic or glass, and has a substantially rectangular cross section. That is, the prism block 16 has a pair of parallel reflecting surfaces 32 and 34 having a length A and a pair of parallel reflecting surfaces 36 and 38 having a length B (> A). The reflection surfaces 32 and 38 are supported by a support member (not shown) so that the angle of the reflection surfaces 32 and 38 is 45 degrees with respect to the optical axis of the incoming / outgoing light beam.
[0012]
The light source 14 and the roller 24 are arranged on the left and right sides of the optical axis of light from the document 30 in a space defined by the lower reflecting surfaces 32 and 38 of the prism block 16 and the bottom surface of the casing 12. Have been. By employing such an arrangement, the distance between the light source 14 and the roller 24 can be reduced, and the scanner can be made thinner in the thickness direction (the left-right direction in FIG. 1).
[0013]
Generally, since the diameter of the roller 24 is larger than the diameter of the light source 14 for illumination, the light source 14 is arranged below the short-side reflecting surface 32 and the roller 24 is arranged below the long-side reflecting surface 38. It is preferable to arrange them.
A flat portion (incident surface) 40 substantially parallel to the surface of the document 30 is formed near the intersection of the lower reflecting surfaces 32 and 38 of the prism block 16, and the upper reflecting surfaces 34 and 36 are similarly formed. A flat portion (emission surface) 42 parallel to the surface of the document 30 is also formed near the intersection line ridge. The entrance surface 40 and the exit surface 42 are formed in such a size that the reflection surfaces 32, 38, 34, 36 do not hinder the reflection.
[0014]
As described above, by providing the incident surface 40 and the exit surface 42 perpendicular to the incoming and outgoing rays, it is possible to prevent the reflection and scattering of light due to the vertex of the intersection line. Further, if the width of the light exit surface 42 is small, the light amount in the sagittal direction becomes small and the resolution is reduced. Therefore, it is necessary to determine the width of the light exit surface 42 to the extent that the light amount in the sagittal direction can be sufficiently obtained.
[0015]
The light from the original 30 that has entered the casing 12 through the slit 28 is incident on the prism block 16 from the incident surface 40, and is reflected by the reflecting surface 36 to the right by 90 degrees in the drawing. Are reflected in the order of 34, 38, 32,... And are finally emitted from the emission surface 42 to the outside of the prism block 16.
A lens 18 and a CCD 20 are disposed above the prism block 16, and light emitted from the prism block 16 is guided to the CCD 20 via the lens 18. The light incident on the light receiving surface of the CCD 20 is converted into an electric signal corresponding to the light intensity, and the electric signal is guided to the scanner circuit 22. Then, the information of the document image is obtained by the image signal processing means of the scanner circuit 22.
[0016]
The roller 24 is provided with a unit (not shown) for detecting the number of rotations, such as an encoder, so that the position and the amount of movement of the scanner 10 can be detected.
Next, the operation of the handy scanner configured as described above will be described. 3 to 6 are explanatory diagrams in which the prism block 16 is geometrically modeled. It has a set of parallel reflecting surfaces 32, 34 of length A and a set of parallel reflecting surfaces 36, 38 of length B (> A), and these two sets of parallel planes of different lengths In a reflection optical system which is orthogonal to each other, a reflection optical path when light enters from the lowest vertex (incident point) indicated by a white circle in the drawing will be described in relation to a length ratio (A: B).
[0017]
FIG. 3 shows a state where A: B = 3: 4. Light that has entered the prism block 16 upward from the incident point indicated by a white circle in the drawing is reflected rightward by 90 ° in the drawing on the reflection surface 36 (hereinafter, referred to as a first reflection surface), and thereafter, is reflected by the reflection surface 34 (hereinafter, referred to as a first reflection surface). , A second reflecting surface), a reflecting surface 38 (hereinafter, referred to as a third reflecting surface), and a reflecting surface 32 (hereinafter, referred to as a fourth reflecting surface) in this order, and finally the first reflecting surface again. The light is reflected at 36 and is emitted out of the prism block 16 from the vertex (emission point) at the right end indicated by a black circle in the figure. In this case, the total number of reflections is five, and the optical path length is 4 × 2 ^1/2 × A.
[0018]
FIG. 4 shows a state where A: B = 3: 5. Light that has entered the prism block 16 upward from the incident point indicated by a white circle in the drawing is reflected rightward by 90 degrees in the drawing on the first reflecting surface 36, and thereafter, the second reflecting surface 34, the third reflecting surface 38, The light is reflected in the order of the first reflecting surface 36, the fourth reflecting surface 32, and the third reflecting surface 38, and is emitted out of the prism block 16 from an upper vertex (emission point) indicated by a black circle in the drawing. In this case, the total number of reflections is 6, and the optical path length is 5 × 2 ^1/2 × A.
[0019]
FIG. 5 shows a state where A: B = 4: 5. Light that has entered the prism block 16 upward from the incident point indicated by a white circle in the drawing is reflected by the first reflecting surface 36 to the right by 90 degrees in the drawing, and thereafter, in order, the second reflecting surface 34 and the third reflecting surface 38. , The fourth reflecting surface 32, the first reflecting surface 36, the second reflecting surface 34, and the third reflecting surface 38 in this order, and are emitted out of the prism block 16 from the left vertex (emission point) indicated by a black circle in the drawing. . In this case, the total number of reflections is 7, and the optical path length is 5 × 2 ^1/2 × A.
[0020]
FIG. 6 shows a state where A: B = 3: 7. Light that has entered the prism block 16 upward from the incident point indicated by a white circle in the drawing is reflected at least once by each reflection surface, and is reflected eight times in total from the upper emission point indicated by a black circle in the drawing to the prism block 16. It is emitted outside. In this case, the optical path length is 7 × 2 ^1/2 × A.
As described above, by changing the ratio of A: B, the reflection path and the number of reflections are changed, and the emission direction can be appropriately changed to the right, left, and upward directions, and the optical path length can also be changed as appropriate. . The ratio to be used is determined according to the required optical path length based on the conjugate length defined by the lens 18 and the arrangement relationship between the slit 28, the lens 18, and the CCD 20.
[0021]
In a vertical scanner in which the slit 28, the lens 18 and the CCD 20 are arranged substantially linearly in the vertical direction as shown in FIG. 1, the incident light beam and the outgoing light beam become parallel as shown in FIGS. Adopt something. The scanner 10 shown in FIG. 1 employs a prism block 16 of A: B = 9: 11 (total number of reflections = 18 times, optical path length = 11 × 2 ^1/2 × A).
[0022]
With this configuration, the number of reflections can be increased or decreased according to the ratio (A: B) of the lengths of the two sets of parallel reflecting surfaces, and a relatively long optical path length can be formed without adding a conventional folding mirror. be able to. Thereby, there is an advantage that the fine adjustment of the angle of the mirror is not required, and further downsizing can be achieved.
When the scanner 10 shown in FIG. 1 is moved in one direction (rightward or leftward in the figure) along the surface of the original 30, the rollers 24 rotate while contacting the original 30, and the roller 24 rotates between the scanner 10 and the original 30. With the distance kept constant, the scanner 10 moves smoothly. Then, while detecting the position of the scanner 10 based on the rotation of the roller 24, the light from the surface of the document 30 is sequentially guided to the CCD 20 through the above-described prism block 16 and the lens 20, so that the image information of the document 30 is obtained. Can be obtained.
[0023]
FIG. 8 shows another embodiment of the present invention. In the figure, the same or similar members as those of the embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. The scanner 10 shown in FIG. 1 is arranged such that the optical axis connecting the lens 18 and the CCD 20 is arranged substantially parallel to the surface of the original 30, and the light incident from the slit 28 is reflected by the prism block 16 and emitted rightward in the figure. Has become. Reference numeral 25 denotes an auxiliary roller. The reflecting surfaces 32 and 38 below the prism block 16 are supported by a support member (not shown) so that an angle of θ = 45 degrees with respect to the optical axis of the incoming / outgoing light beam. The light source 14 and the roller 24 are disposed on the left and right sides of the space defined by the bottom surface of the casing 12 with the optical axis of the incident light beam separated.
[0024]
By employing such an arrangement, the distance between the light source 14 and the roller 24 can be reduced, and the size of the scanner in the horizontal direction (the horizontal direction in FIG. 8) can be reduced.
As described above, since the emission direction of the emitted light beam can be changed according to the ratio of the lengths of the two parallel planes, it is easy to design various forms according to the positional relationship between the slit 28 and the lens 18. Is possible.
[0025]
In the above embodiment, the case where the reflecting surfaces 32 and 38 below the prism block 16 form an angle of θ = 45 degrees with respect to the optical axis of the incident and outgoing light rays is arranged. It is also possible.
In the above embodiment, the prism block 16 has been described as an example. However, the present invention is not limited to this, and an optical mirror may be combined. That is, irrespective of the members constituting the reflection surface, the light guided into the area occupied by the medium (plastic, glass, air, etc.) surrounded by the two sets of parallel reflection surfaces is applied to each surface (4) of the reflection surface. The surface may be configured to be reflected at least once or more and emitted from the medium region.
[0026]
For example, a reflection optical system equivalent to the prism block 16 shown in FIGS. 9A and 9B can be configured by combining four plate-like mirrors 52, 54, 56 and 58 as shown in FIG. In this case, a gap (opening) 60 is provided at the intersection of the mirror 52 (corresponding to the fourth reflecting surface 32 in FIG. 8) and the mirror 58 (corresponding to the third reflecting surface 38 in FIG. 9), and An entrance corresponding to 40 is formed. A gap (opening) 62 is provided at the intersection of the mirror 54 (corresponding to the second reflection surface 34 in FIG. 9) and the mirror 58 to form an exit port corresponding to the exit surface 42 described above.
[0027]
In the above-described embodiment, a case has been described where two sets of parallel reflecting surfaces form 90 degrees. However, the angle at which the two sets of parallel reflecting surfaces intersect is not limited to 90 degrees, and as shown in FIG. Alternatively, the two sets of parallel reflecting surfaces may form 60 degrees and 120 degrees.
In this case, as shown in the figure, an incident surface 40 that is substantially perpendicular to the incident light is formed on one of the intersection ridges that forms an angle of 120 degrees, and the other intersection that forms an angle of 120 degrees. An emission surface 42 substantially perpendicular to the emitted light beam is formed on the ridge.
[0028]
Then, the reflecting surfaces 32 and 38 of the prism block 16 shown in the same figure are arranged at an angle of 60 degrees (30 degrees with respect to the surface of the original 30) with respect to the optical axis of the incoming and outgoing light rays. The light source 14 for illumination and the roller 24 for position detection may be arranged in the left and right space defined by the side and the bottom surface of the casing 12.
By employing such an arrangement, the distance between the light source 14 and the roller 24 can be reduced and the scanner can be reduced in size.
[0029]
【The invention's effect】
As described above, according to the scanner of the present invention, two sets of reflecting optical members for forming an optical path are formed so as to be reflected at least once on each plane of parallel planes having different lengths so as to fold a light path. Arranged at an angle to the optical axis direction of the light beam, and the illumination light source and the moving position detecting means are arranged in the space defined by the lower surface of the reflection optical member and the document surface, right and left across the optical axis of the incident light beam. Since it is arranged, the distance between the illumination light source and the movement position detecting means can be relatively short. As a result, the scanner can be made thinner and smaller.
[Brief description of the drawings]
FIG. 1 is a side perspective view of a handy scanner according to an embodiment of the present invention.
FIG. 2 is a front perspective view of the handy scanner shown in FIG.
FIG. 3 is a diagram used to explain a reflection path of a prism block having two sets of parallel reflection surfaces having different lengths.
FIG. 4 is a diagram used to explain a reflection path of a prism block having two sets of parallel reflection surfaces having different lengths.
FIG. 5 is a diagram used to explain a reflection path of a prism block having two sets of parallel reflection surfaces having different lengths.
FIG. 6 is a diagram used to explain a reflection path of a prism block having two sets of parallel reflection surfaces having different lengths.
FIGS. 7A and 7B are diagrams illustrating an example of a reflection path when an incident light beam incident from below is emitted upward, FIG. 7A is a model diagram of an optical system, and FIG. 7B is an external perspective view of a prism block; .
FIG. 8 is a side view of a handy scanner according to another embodiment of the present invention.
9A and 9B are diagrams illustrating an example of a reflection path when an incident light beam incident from below is emitted in the right direction (lateral direction), where FIG. 9A is a model diagram of an optical system, and FIG. It is a perspective view.
FIG. 10 is a perspective view showing another embodiment of a reflection optical system that emits an incident light beam incident from below in the right direction (lateral direction).
FIG. 11 is a diagram used to explain a reflection path in a case where two parallel reflection surfaces are configured to form 60 degrees or 120 degrees.
[Explanation of symbols]
10 scanner 12 casing 14 light source (light source for illumination)
16 ... Prism block (reflective optical member)
18 Lens 20 Line sensor (CCD)
22 scanner circuit 24 roller (moving position detecting means)
30 original 32, 34, 36, 38 reflecting surface 40 incident surface 42 emitting surface 52, 54, 56, 58 mirror

Claims (3)

A scanner that is moved along the original surface while illuminating the original surface with a light source for illumination, guides light from the original surface to a line sensor via a lens, and reads image information of the original surface,
The two sets of parallel planes having different lengths, and the light from the document surface incident on the medium region surrounded by the two sets of parallel planes is reflected at least once by each of the parallel planes, and A reflecting optical member for forming an optical path that is emitted toward the lens;
Moving position detecting means for detecting a relative moving amount between the scanner and the document surface,
Wherein the reflection optical member is arranged to be inclined with respect to the direction of the incident optical axis of light from the document surface, and the illumination is provided in a space formed between the lower surface of the reflection optical member and the document surface. A scanner, wherein the light source for use and the moving position detecting means are disposed on the left and right sides of the incident optical axis of the light from the document surface. The two sets of parallel planes having different lengths form approximately 90 degrees with each other, and the reflection optical member is disposed at an inclination of approximately 30 degrees or approximately 45 degrees with respect to the direction of the incident optical axis of light from the document surface. The scanner according to claim 1, wherein: Out of the reflection surfaces on the lower surface of the reflection optical member, the light source for illuminating the document is disposed below the reflection surface on the short side, and the movement position detection unit is disposed below the reflection surface on the long side. The scanner according to claim 1, wherein

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