JP2002368256A - Oscillating optical unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an oscillating optical unit, in which a movable mirror is eliminated by making a light-emitting element and a light-receiving element oscillate directly, and the size and weight can be reduced by decreasing the number of components. SOLUTION: The oscillating optical unit comprises a housing 41, in which a light-emitting element 35, a projection lens 39, a light-receiving element 37, and a condenser mirror 49 for the light-receiving element are disposed; a frame supporting the housing 41 turnably about a turning shaft 55 orthogonal to the optical axis of the projection lens 39; a plurality of conductive rails 57 exposed on the outer surface of the housing 41, while conducting to the lead terminals of the light-emitting element 35 and the light-receiving element 37; and a plurality of conductive brushes each having a base end secured to the frame and a free forward end which is made to slide respective conductive rails 57.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oscillating optical unit for reading a bar code, and more particularly, to a compact optical system in which an optical system such as a light emitting element and a light receiving element can be directly oscillated to eliminate a movable mirror. The present invention relates to an improved technology that can be used.

[0002]

2. Description of the Related Art In recent years, many stores and factories attach a bar code representing digital information to an article and optically scan the bar code to read the information, thereby managing the sales of products and the production of products. And so on. In general, this type of bar code irradiates light to the bar code and photoelectrically converts the intensity of the reflected light to read information from a combination of detection signals.

That is, as shown in a conceptual diagram of FIG. 8, light from a light emitting element 1 is stopped down by a light emitting lens 3, this light is reflected by a mirror 7 of a scan mirror 5, and irradiates a bar code 9. In order to irradiate light over the entire area of the bar code 9, the mirror 7 is swung. The swinging is performed by inserting the magnet 11 attached to the mirror 7 into the drive coil 13 and causing the drive coil 13 to attract and repel the magnet 11 to the drive coil 13 by, for example, passing positive and negative currents at a constant period. The mirror 7 is swung about the pivot 15 as a support axis.

On the other hand, the light radiated on the surface of the bar code 9 returns to the mirror 7 again with a change in the amount of light of the bar code due to black and white, while being irregularly reflected. To electrically convert the change in the amount of light to output. In order to improve reading accuracy,
A band pass filter (BPF) is provided on the front surface of the light receiving element 19.
21 is provided to prevent the collection of unnecessary light other than the emission light frequency.

An optical unit for reading a bar code shown in FIG. 9 is provided as a device that implements such a reading method. The configuration of the optical unit includes a light emitting mechanism A in which a light emitting element 1 and a light emitting lens 3 are accommodated in a housing 25, a light receiving element 19 and a light receiving lens 17, as shown in the figure.
The light receiving mechanism B in which the BPF 21 is housed in the housing 27 is mounted on the substrate 29. Electrical connection within each of the housings 25 and 27 is performed by wire bonding or the like. Then, the mirror 7 of the scan mirror 5 is centered on the pivot 15.
Are arranged to be swingable. The light emitting mechanism A, the light receiving mechanism B, and the scan mirror 5 are housed in a frame (not shown) to form a bar code reading optical device.

[0006]

However, the optical unit for reading barcodes described above generally has
Since the light emitting element and the light receiving element are fixed and the light is swung by swinging the movable mirror, a space for installing the movable mirror is required, and the number of parts is increased. There was a limit to weight reduction. In addition, it is necessary to adjust the relative positions of the light emitting / receiving element and the movable mirror, which increases the man-hours for the adjustment work and has a problem that the relative position accuracy tends to vary. On the other hand, there are various problems in reading the bar code by eliminating the movable mirror and directly swinging the light emitting element and the light receiving element. That is, when the light emitting element and the light receiving element are swingably supported, electrical wiring must be provided between the swinging body and a housing that supports the swinging body, and a space for accommodating the electrical wiring is required. It became an obstacle to miniaturization. In addition, disconnection may occur due to bending fatigue of the electric wiring, and there is a possibility that reliability may be reduced. Furthermore, when a large number of electrical wires are connected to the oscillator,
Oscillation resistance due to the rigidity of the wiring increased, and a large driving mechanism was required, which also hindered miniaturization. The present invention has been made in view of the above circumstances, and by enabling direct swinging of a light emitting element and a light receiving element, eliminates a movable mirror, reduces the number of parts, and achieves miniaturization and weight reduction. It is another object of the present invention to provide an oscillating optical unit capable of realizing cost reduction and non-adjustment.

[0007]

According to a first aspect of the present invention, there is provided an oscillating optical unit comprising a light emitting element, a light projecting lens, a light receiving element, and a light-collecting mirror for the light receiving element. A housing, a frame that rotatably supports the housing around a rotation axis orthogonal to the optical axis of the light-projecting lens, and a light-emitting element, which is electrically connected to respective lead terminals of the light-receiving element, and A plurality of conductive rails provided to be exposed on the outer surface of the housing, and a plurality of conductive brushes for fixing a base end to the frame and making a free-end tip slidably contact each of the conductive rails. Features.

In this oscillating optical unit, a light emitting element, a light projecting lens, a light receiving element, and a light-collecting mirror for the light receiving element are provided in a housing, and the housing is rotatably supported by a frame. Scanning can be performed by directly swinging the light receiving element, and a movable mirror, which is conventionally required for scanning irradiation light and receiving reflected light, becomes unnecessary. Also, the conductive rail is exposed on the housing,
The conductive brush is slid on the conductive rail to extract signals from the oscillating light-emitting element and light-receiving element to the outside, resulting in weight and rigidity compared to a structure in which a plurality of electric wires are directly connected. Swing resistance is reduced, and disconnection due to bending fatigue of wiring is eliminated.
There is no need to secure wiring space. And since a movable mirror becomes unnecessary, the relative position adjustment with respect to a light emitting element and a light receiving element also becomes unnecessary.

According to a second aspect of the present invention, in the swing optical unit, the housing has an opening for opening an internal space, and the light emitting element and the light emitting element are arranged such that the light projecting direction and the light receiving direction are opposite to each other on the same straight line. The light receiving element and the light receiving element are arranged back to back to form a light emitting and receiving package, the light emitting lens is provided in front of the light emitting element of the light emitting and receiving package, and the light receiving element faces the internal space. A light emitting and receiving package is fixed to the opening of the housing, and a concave light collecting mirror for the light receiving element facing the light receiving element is provided in the internal space of the housing.

In this oscillating optical unit, light emitted from the light emitting element of the light emitting / receiving package irradiates an object to be irradiated (for example, a bar code), and the light becomes reflected light having the same optical axis to form a concave light receiving surface. The light enters the light receiving element via the element condensing mirror. In other words, the outgoing light and the reflected light travel on the same optical axis at the same time, and it is possible to project and receive light in a small light beam (beam) cross section. This eliminates the necessity of arranging the light emitting element and the light receiving element side by side facing the irradiation target,
The device can be made compact. And an oscillating body (ie, a housing) supporting the light emitting and receiving package.
Since the whole can be reduced in size, the weight of the oscillating body is reduced, and the oscillating structure is more easily realized.

According to a third aspect of the present invention, in the swing optical unit, an outer shape of a cross section in a direction perpendicular to the rotation axis at a rear portion of the housing is formed in an arc shape centering on the rotation axis. .

In this swing optical unit, since the rear portion of the housing has an arc shape, the corner portion does not hit the bottom plate of the frame when the housing swings, and the rear portion of the housing and the bottom plate of the frame are minimized. And a compact swing structure can be realized.

According to a fourth aspect of the present invention, in the oscillating optical unit, at least a pair of the conductive rails long in the oscillating direction of the housing are arranged side by side with a gap in the oscillating direction of the housing. Each of the pair of conductive brushes is slid in contact with the other of the pair of conductive rails, and the other of the pair of conductive brushes is slid in contact with one of the pair of conductive rails. It is characterized by.

In this oscillating optical unit, the conductive brushes intersect and make sliding contact with each other. Therefore, of the pair of conductive rails arranged in the oscillating direction, a distant conductive rail is slid using a long conductive brush. The structure which makes it possible becomes possible. As a result, compared to a structure in which a short conductive brush is used to make sliding contact with a closer conductive rail, the elastic force and spring property of the conductive brush are increased, and a highly reliable sliding contact structure is obtained.

According to a fifth aspect of the present invention, in the swing optical unit, at least a pair of the conductive rails which are long in a swing direction of the housing are arranged side by side with a gap therebetween in a swing direction of the housing. One of the conductive brushes is brought into sliding contact with the other of the pair of conductive rails, a through hole is formed in one of the conductive brushes, and the other of the pair of conductive brushes is inserted into the through hole to slide on one of the pair of conductive rails. It is characterized by contact.

In this oscillating optical unit, a pair of conductive brushes cross each other by inserting the other conductive brush into a through-hole formed in one conductive brush. Among them, a structure in which a long conductive brush is slid in contact with a distant conductive rail in a smaller space becomes possible. As a result, compared to a structure in which a short conductive brush is used to slidably contact a closer conductive rail, the elastic force and spring property of the conductive brush are increased, and a highly reliable compact sliding contact structure is obtained.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a swing optical unit according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a main part of a swing optical unit according to the present invention, FIG. 2 is a view along arrow AA in FIG. 1, and FIG. 3 is a view along arrow BB in FIG.

As shown in FIG. 1, the swing optical unit according to the present invention has a light emitting and receiving package 33 at a main part thereof. The light emitting and receiving package 33 is mounted on the die pad 34 so that the light emitting direction and the light receiving direction are opposite on the same straight line.
And a light-emitting element 35 and a light-receiving element 37 arranged back to back. The light emitting element 35 includes a monitor PD for controlling the laser output to a predetermined amount. The light emitting and receiving package 33 supports the light emitting element 35 and the light receiving element 37 inside a cylindrical package 33a having openings at both ends such that the optical axis coincides with the central axis. At the opening on the light emission side of the package 33a in front of the light emitting element 35, a fitting shape part into which the light projecting lens 39 is incorporated is formed.
The light projecting lens 39 slides in the axial direction of the fitting shape portion to perform necessary focus adjustment, and then adheres the outer periphery and fits the fitting shape portion.

The light emitting and receiving package 33 is supported by a housing 41 made of a resin material or the like. The housing 41 has a cylindrical internal space 43, one end of which is opened as an opening 45. The housing 41 has a pair of support rods 47, 47 shown in FIG. 3 fixed to the end face of the opening 45, and the support rods 47, 47 are fixed to the package 33a. Fixed to. Thereby, the light emitting and receiving package 33 is
The light receiving element 37 faces the internal space 43 and the light emitting element 35
And the optical axis of the light receiving element 37 coincides with the central axis of the internal space 43.

The housing 41 includes a light emitting and receiving package 33.
A light-receiving element condensing mirror 49 having a concave shape facing the light-receiving element 37 is provided in the internal space 43. The light-receiving element condensing mirror 49 can be formed by, for example, forming the bottom surface of the internal space 43 into a concave shape, and depositing a metal thin film such as silver or aluminum or a dielectric multilayer film on the surface.
In addition, the light-receiving element condensing mirror 49 may be configured by fixing a concave mirror formed separately.

As described above, the housing 41 includes the light emitting element 35, the light receiving element 37, the light projecting lens 39, and the light receiving element condensing mirror 49.

As shown in FIG. 2, a plurality of lead terminals 51 are provided on the package 33a.
And protrudes to the outer periphery of the opening 45 of the housing 41. In this embodiment, for example, the light emitting element 3
A total of six lead terminals 51 protrude, three for five and three for the light receiving element 37. These respective lead terminals 51 are electrically connected to electrodes of the light emitting element 35 and the light receiving element 37 by bonding wires 53 shown in FIG.

In this embodiment, the housing 41 is
As shown in FIG. 2, the front view is a square shape. On both parallel side surfaces (upper and lower surfaces in FIG. 2) of the housing 41, a rotating shaft 55 projects in a direction perpendicular to the optical axis. The light emitting and receiving package 33 is swingably supported by a frame described later via the rotating shaft 55.

As shown in FIG. 3, the outer shape of the cross section of the housing 41 in a direction perpendicular to the rotation shaft 55 at the rear portion has an arc shape centered on the rotation shaft 55. Since the rear portion of the housing 41 has such an arc shape, the housing 4
When the oscillating member 1 swings, the corner portion does not hit the bottom plate of the frame described later, and the rear portion of the housing 41 and the bottom plate of the frame can be brought close to each other to a minimum, and the oscillating structure becomes compact.

As shown in FIG. 3, on both parallel side surfaces of the housing 41 (other parallel both side surfaces sandwiched between both side surfaces on which the rotating shaft 55 is protruded), the lead terminals 51 are electrically connected. The plurality of conductive rails 57 are integrated and exposed by resin molding. The lead terminals 51 and the conductive rails 57 are electrically connected by, for example, solder 58. Therefore, the conductive rail 57 is connected to the lead terminal 51.
Corresponds to the total of six. The conductive rails 57 extend from both side surfaces of the housing 41 toward the rear end surface. On the rear end face of the housing 41 having an arc-shaped cross section, conductive rails 57 extending three by three from both side faces are provided.
However, they face each other symmetrically with the gap 59 interposed therebetween.
That is, the conductive rails 57 are elongated in the swing direction of the housing 41 on the rear end surface of the housing 41 and are arranged with the gap 59 therebetween in the swing direction of the housing 41.

FIG. 4 is a sectional view showing the entire swing optical unit in which the light emitting and receiving package of FIG. 1 is supported on a frame.
4 is a view taken in the direction of arrows CC in FIG. 4, FIG. 6 is a view taken in the direction of arrows DD in FIG. 5, and FIG. 7 is a cross-sectional view of the swing optical unit in a state where the light emitting and receiving package is swung. As shown in FIG.
Supports the housing 41 so as to be swingable via a rotation shaft 55. That is, the frame 61 supports the housing 41 rotatably about a rotation axis orthogonal to the optical axis. In this embodiment, the housing 41 is in the shape of a bottomed rectangular tube with one end opened.

The frame 61 has a plurality of (in this embodiment, a total of six) conductive brushes 65 on the bottom plate 63 corresponding to the respective conductive rails 57. The base end of the conductive brush 65 is fixed to the bottom plate 63, and the free end is slidably contacted with each of the conductive rails 57. The conductive brush 65 includes a fixed terminal 6 that is conductively fixed to the base end.
2 connects to an external circuit.

In the present embodiment, for example, the three conductive brushes 65a, 65b, 65c on the left side shown in FIG.
57f, the three conductive brushes 65d, 65 on the right side
e, 65f are in sliding contact with the left three conductive rails 57a, 57b, 57c that are electrically connected to the light emitting element 35.

Here, a pair of outer conductive brushes 65a and 65d and upper and lower conductive brushes 65a and 65d and 65c and 65f protruding from the left and right sides of FIG. Crossed. For example, in the upper pair of conductive brushes 65a and 65d, one 65a is slid on the other 57d of the pair of conductive rails 57a and 57d shown in FIG. 6, and the other 65d is slid on the one 57a of the pair of conductive rails 57a and 57d. Let me. Further, in the lower pair of conductive brushes 65c, 65f, one 65c is slidably contacted with the other 57f of the pair of conductive rails 57c, 57f shown in FIG. 6, and the other 65f is connected to one of the pair of conductive rails 57c, 57f.
c.

As described above, the conductive brushes 65a and 65d
(Or 65c and 65f) intersect and slid, so that, of the pair of conductive rails 57a, 57d (or 57c, 57f) arranged in the swinging direction, the farther conductive rail (for example, the conductive rail 57d for the conductive brush 65a). ) Can be configured to be in sliding contact with the long conductive brush 65a. As a result, the elasticity and spring property of the conductive brush are increased, and a highly reliable sliding contact structure is provided, as compared with a structure in which a short conductive brush is used to make sliding contact with a closer conductive rail (for example, the conductive rail 57a for the conductive brush 65a). Will be obtained.

Further, a pair of conductive brushes 6 on the inner side (middle stages arranged in three stages in FIG. 5) protruding from the left and right sides in FIG.
5b and 65e cross each other on the left and right without contact. That is, one of the pair of conductive brushes 65b and 65e is brought into sliding contact with the other of the pair of conductive rails 57b and 57e shown in FIG.
Is formed with a through hole 69. Then, the other 65e of the pair of conductive brushes 65b and 65e is inserted into the through hole 69 to be in sliding contact with one of the pair of conductive rails 57b and 57e.

As described above, the other conductive brush 65e is inserted into the through-hole 69 formed in one conductive brush 65b, and the pair of conductive brushes 65b and 65e intersect. Conductive rails 57b, 57e
Out of the conductive rails (for example, conductive brush 65b)
The structure in which a long conductive brush 65b slides against the conductive rail 57e) can be realized in a small space. Thereby, the elastic force and the spring property of the conductive brush are increased, and a highly reliable and compact sliding contact is achieved, as compared with a structure in which a short conductive brush is used to make sliding contact with a closer conductive rail (for example, the conductive rail 57b with respect to the conductive brush 65b). A structure will be obtained.

The oscillating optical unit 31 thus configured
Then, when the light emitting element 35 emits light by a light emission driving circuit (not shown), the light is focused by the light projecting lens 39 and emitted. This light irradiates a bar code (not shown) and becomes reflected light. At the same time, the housing 41 swings about the rotation shaft 55 as shown in FIG. 7 by driving means (not shown), so that the emitted light is applied to the entire area of the bar code. The light (return light) reflected by the barcode is incident on the light-receiving element condensing mirror 49 and is focused, and the light is received by the light-receiving element 37. The light receiving element 37 photoelectrically converts the light and outputs the bar code pattern to the lead terminal 51 as an electric signal. This output signal is sent to a computer (not shown) via the conductive rail 57, the conductive brush 65, and the fixed terminal 62, where the bar code information is decoded.

As described above, the swing optical unit 31
According to this, by supporting the housing 41 rotatably on the frame 61, scanning can be performed by directly swinging the light emitting element 35 and the light receiving element 37. Conventionally, scanning of irradiation light and reception of reflected light are performed. This eliminates the need for a movable mirror that was necessary for the purpose. Further, the conductive rail 57 is exposed on the housing 41, and a conductive brush 65 is slid on the conductive rail 57 to take out signals from the oscillating light-emitting element 35 and light-receiving element 37 to the outside. Compared with a structure in which wiring is directly connected, swing resistance due to weight and rigidity of wiring is reduced, and disconnection due to bending fatigue of wiring is eliminated.
Further, there is no need to secure a wiring space. Since the movable mirror is not required, and positioning can be performed only by fixing the light emitting / receiving package 33 to a predetermined mounting portion,
Adjustment of the relative position between the light emitting element 35 and the light receiving element 37 can be eliminated.

The light emitted from the light projecting / receiving package 33 is reflected on the same optical axis and enters the light receiving element 37 via the concave light collecting mirror 49 for the light receiving element. In other words, the outgoing light and the reflected light travel on the same optical axis at the same time, and it is possible to project and receive light in a small light beam (beam) cross section. This eliminates the necessity of arranging the light emitting element 35 and the light receiving element 37 side by side so as to face the irradiation target, and makes it possible to make the apparatus compact. The oscillating body (ie, the housing 4) supporting the light emitting / receiving package 33
1) Since the whole can be reduced in size, the weight of the oscillating body is reduced, and the oscillating structure is more easily realized.

[0036]

As described in detail above, according to the oscillating optical unit according to the present invention, the light emitting element, the light projecting lens,
The light-receiving element and the light-collecting mirror for the light-receiving element are installed in the housing, and this housing is supported on the frame so as to be freely rotatable. By abolishing it, scanning can be performed by directly swinging the light emitting element and the light receiving element. As a result, it is possible to reduce the number of parts of the apparatus, achieve downsizing and weight reduction, and realize cost reduction. it can. In addition, a conductive rail is exposed on the housing, and a conductive brush is slid on the conductive rail to take out signals from the oscillating light-emitting element and light-receiving element to the outside, so that a plurality of electric wires are directly connected. As compared with a structure that performs wiring, it is possible to reduce the swing resistance due to the weight and the rigidity of the wiring, to prevent a decrease in reliability due to the bending fatigue of the wiring, and to achieve a space saving by eliminating a wiring space. be able to.
Further, since adjustment of the relative position with respect to the movable mirror becomes unnecessary, it is possible to realize no adjustment.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a swing optical unit according to the present invention.

FIG. 2 is a view taken along the line AA of FIG. 1;

FIG. 3 is a view taken in the direction of arrows BB in FIG. 2;

FIG. 4 is a cross-sectional view illustrating the entire swing optical unit in which the light emitting and receiving package of FIG. 1 is supported on a frame.

FIG. 5 is a view taken in the direction of the arrows CC in FIG. 4;

FIG. 6 is a view as seen from the direction of the arrow DD in FIG. 5;

FIG. 7 is a cross-sectional view of the swing optical unit in a state where the light emitting and receiving package is swung.

FIG. 8 is a conceptual diagram illustrating a conventional optical reading method.

FIG. 9 is a sectional view of a conventional optical device for reading bar codes.

[Explanation of symbols]

31: swing optical unit, 33: light emitting / receiving package, 3
5 light emitting element, 37 light receiving element, 39 light emitting lens, 4
DESCRIPTION OF SYMBOLS 1 ... Housing, 43 ... Internal space, 45 ... Opening, 49
... Condensing mirror for light receiving element, 51... Lead terminal, 55... Rotating shaft, 57... Conductive rail, 61.

Continuation of the front page (72) Inventor Shigeru Niizawa F-term (reference) 2H043 AE02 AE14 AE24 2H045 AG09 BA18 DA02 DA31 5B072 AA03 CC24 LL07 LL11 LL18 5F089 BA05 BB02 BC09 BC22 BC30 CA20 GA10

Claims (5)

[Claims] 1. A housing in which a light emitting element, a light projecting lens, a light receiving element, and a light collecting mirror for a light receiving element are provided, and the housing is rotatable about a rotation axis orthogonal to an optical axis of the light projecting lens. A plurality of conductive rails provided to be electrically connected to respective lead terminals of the light emitting element and the light receiving element and exposed on an outer surface of the housing; and a free end fixed to a base end of the frame. A plurality of conductive brushes for bringing the leading ends into sliding contact with the respective conductive rails. 2. The light-emitting element and the light-receiving element are arranged back-to-back so that the housing has an opening for opening an internal space, and the light-emitting direction and the light-receiving direction are opposite to each other on the same straight line. The light emitting and receiving package is provided, the light emitting lens is provided in front of the light emitting element of the light emitting and receiving package, and the light emitting and receiving package is placed in the opening of the housing such that the light receiving element faces the internal space. The oscillating optical unit according to claim 1, further comprising a concave light-receiving element converging mirror provided in the interior space of the housing so as to face the light-receiving element. 3. The swing according to claim 1, wherein an outer cross section of the rear portion of the housing in a direction perpendicular to the rotation axis is formed in an arc shape centering on the rotation axis. Optical unit. 4. At least a pair of the conductive rails long in the swinging direction of the housing are arranged side by side with a gap in the swinging direction of the housing, and each of the pair of conductive brushes intersects in a non-contact manner. 3. The method according to claim 1, wherein one of the pair of conductive brushes is slid in contact with the other of the pair of conductive rails, and the other of the pair of conductive brushes is slid in contact with one of the pair of conductive rails. The oscillating optical unit as described in the above. 5. At least a pair of conductive rails that are long in the swinging direction of the housing are arranged in parallel with a gap in the swinging direction of the housing, and one of the pair of conductive brushes is the other of the pair of conductive rails. And a through hole is formed in one of the conductive brushes, and the other of the pair of conductive brushes is inserted into the through hole and slidably contacts one of the pair of conductive rails. Item 3. The swing optical unit according to Item 1 or 2.