JPH11337860A - Optical scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive and small-sized optical scanner by providing a second reflection surface reflecting a beam passing through an opening toward a first reflection surface and specifying the depth of the opening. SOLUTION: A scanner part 150 is provided with a movable plate 156 supported on a support body 152 by a pair of hinges 154. The movable plate 156 is provided with the movable plate main body continuing to the hinges 154 and the first reflection surface provided on it, and the movable plate main body is constituted of a base layer 174 and an insulation layer 172, and the first reflection surface is constituted of two sheets of electrodes 158, 160. Further, the opening 170 is formed on the center of the movable plate 156, and further, a stepped through hole 176 is formed on the support body 152, and both are in a similar positional relation. Then, the depth (t) of the opening 170 is constituted so as to satisfy the relation of t<=d (cosα-R<1/2> )/sinα. Where, (d) is the opening size of the opening 156, α is the maximum deflection angle of the movable plate 156 and (R) is a required ratio between light emission quantity from the opening 170 at the no deflection angle and at the maximum deflection angle of the movable plate 156.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small optical scanner capable of scanning light in one or more dimensions.

[0002]

2. Description of the Related Art A lightweight portable bar code reader disclosed in Japanese Patent Application Laid-Open No. 2-178888 will be described.
9A is a front view of the bar code reader, FIG. 9B is a vertical sectional view along line 2-2 in FIG. 9A, and FIG. 9C is 3-3 in FIG. 9B. It is a cross-sectional view along a line.

The light emitted from the laser diode 33 passes through the focusing lens 32 and is applied to the scanning mirror 19b of the scanning light receiving mirror 19. The scanning light receiving mirror 19 has a scanning mirror 19b and a light receiving mirror 19a, and is rotated by a scanning motor 24. The reflected light from the scanning mirror 19b rotated by the scanning motor 24 is scanned, passes through the window 14, and irradiates and scans a bar code outside the head. The reflected light from the bar code is transmitted through the window
4, the light is irradiated to the light receiving mirror 19a of the scanning light receiving mirror 19, and is condensed and detected on the photo sensor 17.

The characteristic of this optical system is that, while scanning the emitted light with the scanning mirror 19b and simultaneously scanning the field of view of the photosensor 17 with the light receiving mirror 19a, the reflected and scattered light from the vicinity of the area where the emitted light is actually irradiated is reflected. It is to detect light selectively.

[0005]

As described above, the optical scanner is generally used together with a light source (laser diode 33), a condenser lens (focusing lens 32), a photodetector (photosensor 17), and the like. In such an optical system, it is necessary to assemble the components by adjusting the positions of the components, and it is difficult to reduce the cost.

Further, a scanning light receiving mirror 19 on the optical scanner is provided.
The incident angle of light to the mirror is made small (close to normal incidence), so that the laser diode 33, the photosensor 17 and the like do not block the reflected light.
Therefore, it is necessary to secure a certain distance from the device 9, and it is difficult to reduce the size of the device.

Further, a focusing lens 32 for determining the focal position of the emitted light is designed so that the information of the bar code at a distance (about several tens cm) relatively far from the bar code scanner can be read. The area of the light receiving mirror 19a is designed to be considerably larger than the area of the scanning mirror 19b in accordance with the distance to the bar code. In such a configuration, since the movable plate (scanning light receiving mirror 19) is large, it is necessary to increase the driving force of the motor 24, and it is difficult to reduce the size of the barcode scanner. Since the scanning mirror which is a plane mirror and the light receiving mirror which is a concave mirror are integrally formed, machining of the mirror is complicated. The present invention
The present invention has been made in view of such circumstances, and an object thereof is to provide an inexpensive and compact optical scanner.

[0008]

An optical scanner according to the present invention comprises a movable plate having an opening through which light passes and a first reflecting surface, a support for supporting the movable plate, and an opening. A second reflecting surface for reflecting the transmitted light toward the first reflecting surface, and the thickness t of the opening is defined by the following (1).
It is characterized by satisfying the expression.

T ≦ d (cos α−R ^1/2 ) / sin α (1) where d is the opening diameter of the opening, α is the maximum deflection angle of the movable plate,
R is a desired ratio of the amount of light emitted from the opening when the movable plate has no deflection angle and at the maximum deflection angle.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an optical scanner according to an embodiment of the present invention. FIG. 1A is a sectional view of the optical scanner. FIG. 1B is a top view of the reflecting portion, and B in FIG.
A cross section taken along line -B is shown in FIG. FIG.
FIG. 1C is a top view of the scanner unit, and FIG. 1A shows a cross section taken along line CC in the figure.

The optical scanner 100 is roughly divided into a reflection section 110
And a scanner unit 150. Scanner unit 1
50 has a movable plate 156 supported by a support 152 by a pair of hinges 154. The movable plate 156 is
It has a movable plate main body continuous with the hinge 154 and a first reflective surface provided thereon, and the movable plate main body is composed of a base layer 174 and an insulating layer 172, and the first reflective surface has two electrodes. 1
58 and 160.

An opening 170 is formed at the center of the movable plate 156, and a stepped through hole 176 is formed in the support 152, and the two are in a coaxial positional relationship. In other words, the opening 170 and the stepped through-hole 176 have a coaxial positional relationship with the movable plate 156 and the support 1, respectively.
52.

The electrodes 158 and 160 function as a first reflecting surface, and are used for driving the movable plate 156 to swing about a hinge 154. The electrodes 158 and 160 are substantially separated from each other along the swing axis, and are insulated from each other. Have been. The electrode 158 protrudes beyond the pivot axis toward the electrode 160 at the center, and an opening 170 is formed in the protruding portion. Thus, the opening 170 is provided with the electrode 15 having good workability.
8, it is made into a good shape with high dimensional accuracy.

The electrodes 158 and 160 are connected to the support 1 via wires 162 and 164 extending through the hinge 154, respectively.
52, and is electrically connected to the electrode pads 166 and 168 provided on the electrode pad 52, and has a potential corresponding to an electric signal supplied to the electrode pads 166 and 168.

The support 152 is made of a conductive material and is kept at the ground potential. Therefore, the electrode 158 and the ground plane 17
8 and between the electrode 160 and the ground plane 178, an electrostatic force corresponding to the potential of the electrode 158 and the potential of the electrode 160 is generated. As a result, the movable plate 156
Between electrode 8 and ground plane 178 and electrode 16
It swings around the hinge 154 corresponding to the difference in electrostatic force generated between the zero and the ground plane 178.

On the other hand, the reflecting section 110 is composed of a mirror 116 supported by a substrate 112 via a transparent film 114.
Reflective surface. The transparent film 114 is made of, for example, a glassy thin film. In the figure, the mirror 116 is the transparent film 114
, But may be provided below the transparent film 114.

The substrate 112 is mounted on a support 152 of the scanner unit 150, and the mirror 116 is provided with an opening 170 of the movable plate 156 and a stepped through hole 176 of the support 152.
It is located on the axis of. In other words, the reflection unit 110
Is such that the mirror 116 is positioned on the axis of the opening 170 of the movable plate 156 and the stepped through hole 176 of the support 152.
It is attached to the scanner unit 150.

Next, an example in which the optical scanner of FIG. 1 is applied to a bar code reader will be described with reference to FIG. A collimator lens 304 is disposed in front of the optical scanner 100. The optical fiber 302 is inserted into a stepped through hole 176 provided in the scanner unit 150 of the optical scanner 100, and the end face of the optical fiber 302 is connected to the stepped through hole 176.
Is in contact with the step. The optical fiber 302 is connected to a light source unit and a light detection unit (not shown), and guides light for reading to the optical scanner 100 and guides light from an object to be read to the light detection unit.

The light emitted from the end face of the optical fiber 302 illuminates the movable plate 156 while spreading through the opening of the stepped through hole 176. The light that has passed through the opening 170 is reflected by the second reflecting surface 116, and then is reflected by the first reflecting surface 158.
And 160, the light is reflected from the transparent film 114 to the optical scanner 10
0 is projected outside. The light leaving the optical scanner 100 is
The light is converted into parallel light by the collimating lens 304 and is projected forward.

As described above, the movable plate 156 of the optical scanner 100 swings around the hinge 154 according to the electric signal supplied to the electrode pads 166 and 168. Therefore, when an offset voltage is applied to each of the electrode pads 166 and 168 and a sine wave maintained at a positive potential and having a phase difference of 180 degrees is applied, the movable plate 156 is periodically inclined. As a result, the light projected via the collimating lens 304 is reciprocally scanned left and right.

The light projected through the collimating lens 304 illuminates a bar code to be scanned. The return light from the bar code includes scattered light and zero-order reflected light,
When a detection method using reflected light is used, the optical path at the time of projection is reversed, that is, the collimating lens 304, the transparent film 114, the first reflecting surfaces 158 and 160, the second reflecting surface 116, and the opening 170 are moved. Then, the light enters the end face of the optical fiber 302, is guided to a light detection unit (not shown), and the information contained therein is read.

In this bar code reader, the optical fiber 3
02, optical scanner 100 and collimating lens 30
4 are coaxially arranged, and inside the optical scanner 100, the opening 170, the second reflecting surface 116, the first reflecting surfaces 158 and 1
Since 60 is arranged coaxially, positioning can be easily performed. Also, thanks to the structural features of the optical scanner 100, it is a very small barcode reader.

As can be seen from FIG. 3, the optical scanner 100 has the property that the apparent aperture diameter changes according to the inclination of the movable plate 156. In this specification, the apparent opening diameter means the opening of the light introducing portion, that is, the opening of the stepped through hole 176, or the optical fiber 3 in FIG.
02 refers to the diameter of the hole defined by the opening 170 as viewed from the end face.

The apparent opening diameter depends not only on the inclination of the movable plate 156 but also on the thickness of the opening 170. In this specification, the thickness of the opening 170 refers to the thickness of the member 180 defining the opening 170, which corresponds to the total thickness of the electrode 158 and the insulating layer 172 in FIG. Does not include thickness.

The vibration of the movable plate 156 for scanning changes the apparent aperture diameter, and causes the light to be kicked due to the thickness of the aperture 170. This causes a change in the amount of light depending on the scanning position of light emitted outside the optical scanner 100. Such a change in the emitted light has a great effect and burden on the detection system.

That is, from the viewpoint of the detection system, the optical scanner 1
The emitted light from 00 is preferably constant. In order to achieve a constant intensity of emitted light, it is only necessary to reduce the variation in the apparent opening diameter, and to achieve this, the thickness of the member 180 defining the opening 170 may be reduced. However, the decrease in the thickness of the member 180 that defines the opening 170
The mechanical strength of the opening 170 is reduced, which causes the opening 170 to be broken or distorted due to vibration. Therefore, the member 180 that defines the opening 170 actually needs to have a certain thickness in order to secure structural strength.

In consideration of such circumstances, it is preferable that the thickness t of the opening satisfies the following expression (1) in consideration of the maximum deflection angle α of the movable plate 156. t ≦ d (cos α−R ^1/2 ) / sin α (1) where d is the actual opening diameter of the opening 170, and R is the distance from the opening when the movable plate has no shake angle and at the maximum shake angle. This is a desired ratio of the light emission amount.

The reason why the equation was not defined according to the aperture diameter is that the aperture affects the NA of the emitted light. In particular, when this optical system is used in a confocal microscope or the like, the aperture diameter is smaller than that of the microscope. This is because it has been determined that the aperture diameter should be determined by the optical design because it greatly affects the performance of the optical disc.

Equation (1) derives the aperture diameter at the maximum deflection angle as shown in FIG. 3, and the ratio of the aperture diameter at the non-deflection angle is
It is configured so that the rate of change can be suppressed to a desired rate or less.
This equation does not mention the energy distribution of the light beam passing through the aperture. This is because the distribution is not necessarily determined uniquely, and the expression (1) ignoring the distribution of the light beam includes the case where the light beam has a distribution.

In the bar code reader shown in FIG. 2, light is introduced into the optical scanner by an optical fiber, but the optical fiber may be a single mode or a multi mode. Of course, a semiconductor laser or an LE
A similar functional body can be obtained by arranging D and the like. in this case,
Heat generation of the laser, which is often a problem in semiconductor lasers, can be suitably suppressed by increasing the cooling efficiency by closing the stepped through holes 176 with a material having good thermal conductivity.

The optical scanner 100 is applied to a bar code reader by disposing a collimating lens 304 in front of the optical scanner 100 in FIG.
It may be applied to a confocal optical system by replacing 4 with a condenser lens.

When the optical scanner 100 is applied to a confocal optical system, a single-mode fiber is used as an optical fiber, thereby achieving "Micromachined scanning confocal optic."
al microscope "OPTIC LETTERS, Vo1.21, No10, May, 19
Similarly to the micro-confocal microscope shown in 96, a confocal optical system using a single mode fiber core as a confocal pinhole can also be configured.

When a multimode fiber is used as the optical fiber, a confocal optical system having the aperture 170 as a pinhole can be constructed. In addition, the optical scanner 100 has wide versatility, for example, it can be used as an optical scanning unit for a laser printer.

Next, a method of manufacturing the optical scanner 100 shown in FIG. 1 will be described. The optical scanner unit 150 is the same as that shown in FIG.
, The silicon substrate 182 and the silicon oxide film 184
It is manufactured by applying a semiconductor manufacturing technique to an SOI wafer constituted by the silicon substrate and the silicon substrate 186. Electrode 15
8 and 160, the wirings 162 and 164, and the electrode pads 166 and 168 are produced by, for example, forming a metal film on a silicon nitride film 188 formed on a silicon substrate 184 and patterning the same. In particular, the electrodes 158 and 160 are preferably made of a metal film having a high reflectivity, such as an aluminum film formed by vapor deposition.

The movable plate 156 and the hinge 154 are manufactured by performing etching through a mask corresponding to the contour. The hinge 154 is composed of a silicon nitride film 188, and the base layer 174 of the movable plate 156 is a silicon substrate 18.
6, and the insulating layer 172 is formed of the silicon nitride film 188. The support 15 having the ground surface 178
2 is made of a silicon substrate 182, which is kept at the ground potential, so that the silicon substrate 182 is made of low-resistance silicon mixed with a large amount of impurities.

According to the manufacturing method described above, the hinge 154
Is composed of a silicon nitride film 188, on which a wiring 162 is formed.
And 164 are formed, but the hinge 154 and the wiring 16
As shown in FIG. 4, the hinges 2 and 164 may be configured such that the hinge 154 is formed of an organic film such as polyimide, and the wiring 162 runs inside the hinge 154. The details of such a structure are disclosed in Japanese Patent Application Laid-Open No. 10-20226 by the present applicant, and the technical contents thereof are incorporated herein by reference.

The reflection section 110 can be manufactured on a normal silicon substrate. Since the thickness of the silicon substrate affects the optical path length, a silicon substrate having a thickness according to the optical design is prepared. A transparent film 114 is formed by forming a silicon oxide film or a silicon nitride film on a silicon substrate, and a high-reflection film such as aluminum is selectively formed thereon to form a second reflection film 116. The substrate 112 is manufactured by selectively removing the silicon substrate by crystal anisotropic etching until the transparent film 114 is exposed.

When the durability is not sufficient with only a silicon oxide film or a silicon nitride film, the film may be reinforced with an organic film such as polyimide. In this case, the polyimide used is desirably a fluorinated polyimide containing fluorine. This is because the fluorinated polyimide has properties optically similar to glass.

Various modifications and changes can be made to the components of the above-described embodiment. FIG. 5 shows an optical scanner according to a first modification. In the drawings, members denoted by the same reference numerals as those of the members of the above-described embodiment indicate the same members, and the detailed description thereof will be omitted to avoid duplication. Explain with emphasis.

As shown in FIG. 5, in the optical scanner 100 of this modified example, the grating lens 11 is provided on the transparent film 114 of the reflecting section 110 and around the second reflecting surface 116.
8 are provided. The grating lens 118
For application to a barcode reader, it is designed to function as a collimator lens, and for application to a confocal optical system, it is designed to function as a condenser lens.

The grating lens 118 is manufactured by processing a silicon oxide film, a silicon nitride film, or a transparent film 114 formed of polyimide by a micromachining technique. The grating lens 118 manufactured in this way has extremely high dimensional accuracy. Therefore, assembling can be easily performed as compared with a device in which the optical scanner 100 is combined with a separate optical element.

The height of the grating 118 is 100 μm or less, depending on the performance of the lens. Therefore, the device configuration can be made very small as compared with a device in which the optical scanner 100 is combined with a separate optical element.

FIG. 6 shows an optical scanner according to a second modification.
In the drawings, members denoted by the same reference numerals as those of the members of the above-described embodiment indicate the same members, and the detailed description thereof will be omitted to avoid duplication. Explain with emphasis.

As shown in FIG. 6, in the optical scanner 100 of this modified example, the grating lens 11 is disposed on the transparent film 114 of the reflecting section 110 and around the second reflecting surface 116.
8 are provided. The grating lens 118
For application to a barcode reader, it is designed to function as a collimator lens, and for application to a confocal optical system, it is designed to function as a condenser lens.

Further, another grating lens 120 is provided around the grating lens 118, and the photodetectors 192 and 194 are provided on the movable plate 156 around the electrodes 158 and 160, respectively. . The grating lens 120 has a function of guiding incident light to the photodetectors 192 and 194. The photodetectors 192 and 194 are formed on a silicon substrate 186 constituting the base layer 174 of the movable plate 156 by a semiconductor manufacturing technique.

The grating lens 118 and the grating lens 120 are formed by micro-machining technology.
It is manufactured by processing a transparent film 114 formed of a silicon oxide film, a silicon nitride film, or polyimide. The grating lens 118 and the grating lens 120 manufactured in this manner have extremely high dimensional accuracy. Therefore, assembling can be easily performed as compared with a device in which the optical scanner 100 is combined with a separate optical element.

The step between the grating 118 and the grating lens 120 is 100 μm or less, depending on the performance of the lens. Therefore, the optical scanner 100
The device configuration can be made very small as compared with a device in which is combined with a separate optical element.

The configuration of this modified example is particularly suitable for a device for detecting scattered light, such as a scattered light detection type bar code reader, and can effectively detect light scattered on the surface to be measured.

FIG. 7 shows an optical scanner according to a third modification.
In the drawings, members denoted by the same reference numerals as those of the members of the above-described embodiment indicate the same members, and the detailed description thereof will be omitted to avoid duplication. Explain with emphasis.

As shown in FIG. 7, in the optical scanner 100 of this modification, the movable plate 156 is supported by the movable frame 202 by a pair of hinges 154, and the movable frame 202 is supported by the support 152 by a pair of hinges 204. ing. The hinge 154 and the hinge 204 have their axes orthogonal to each other, the movable plate 156 can swing around the hinge 154 axis, and the movable frame 202 can swing around the hinge 204 axis. That is, the movable plate 156 has a gimbal structure.

As described above, the movable plate 156 is provided with the electrodes 158 and 160 functioning as the first reflection surface, and the electrodes 158 and 160 are connected via the wires 162 and 164, respectively.
It is electrically connected to the electrode pads 166 and 168 provided on the support 152. The movable frame 202 has the electrode 21
2 and 214 are provided.
It is electrically connected to the electrode pads 220 and 222 provided on the support 152 via 16 and 218.

The movable plate 156 has electrode pads 166 and 16
8, the hinge 204 is tilted around the hinge 154 in accordance with the potential applied to the electrodes 158 and 160, and the hinge 204 is tilted in accordance with the potential applied to the electrodes 212 and 214 through the electrode pads 220 and 222. Tilt as an axis. Therefore, the movable plate 156 is moved around the hinge 154 and the hinge 20.
By swinging around the axis 4, the reflected light can be scanned two-dimensionally.

The electrodes 212 and 214 on the movable frame 202 are
The electrodes 158 and 160 on the movable plate 156 may be made of a different material because they only function as electrodes for tilting the movable frame 202 and do not function as reflective surfaces.

It is desirable to design the movable plate 156 and the movable frame 202 such that the natural frequencies are different. this is,
For example, when the movable plate 156 is vibrated by the resonance drive and the movable frame 202 is vibrated by the non-resonance drive, if the two natural frequencies are close to each other, the movable frame 202 causes abnormal vibration due to the influence of the movable plate 156. This may cause a failure. In particular, the movable frame 202 has a smaller maximum deflection angle than the movable plate 156 and easily hits the ground surface 178.

Further, a grating lens 118 is provided on the transparent film 114 of the reflecting section 110 around the second reflecting surface 116. Grating lens 11
Numeral 8 is designed to function as a collimating lens for application to a barcode reader, and to function as a condenser lens for application to a confocal optical system.

The grating lens 118 is manufactured by processing the silicon oxide film, the silicon nitride film, or the transparent film 114 formed of polyimide by a micromachining technique. The grating lens 118 manufactured in this way has extremely high dimensional accuracy. Therefore, assembling can be easily performed as compared with a device in which the optical scanner 100 is combined with a separate optical element.

The height of the grating 118 is 100 μm or less, depending on the performance of the lens. Therefore, the device configuration can be made very small as compared with a device in which the optical scanner 100 is combined with a separate optical element.

The configuration of this modified example is suitable as an optical scanner for a confocal microscope or a laser printer. Further, as in the second modified example, if the movable plate 156 is provided with a photodetector and the transparent film 114 is provided with a photodetector lens, it is suitable as an optical scanner for a two-dimensional barcode reader.

FIG. 8 shows an optical scanner according to a fourth modification.
In the drawings, members denoted by the same reference numerals as those of the members of the above-described embodiment indicate the same members, and the detailed description thereof will be omitted to avoid duplication. Explain with emphasis.

As shown in FIG. 8, in the optical scanner 100 of this modification, the center of the transparent film 114 of the reflecting section 110 is
A convex reflective surface 122 functioning as a second reflective surface is provided. Here, the convex reflective surface 122 refers to a general reflective functional body having the same function as a convex mirror, and need not be a convex reflective surface. For example, it is a reflective element combining a flat mirror and a grating lens. There may be. Such a reflective element is easier to manufacture and more practical than a convex reflective surface.

The convex reflecting surface 122 diffuses and reflects the light incident through the opening 170 to the entire first reflecting surfaces 158 and 160. The second reflecting surface formed of a plane mirror can transmit the first light when the light incident through the opening 170 is close to parallel light or when the distance between the opening 170 and the second reflecting surface is small. Although it is difficult to reflect over a wide range of the reflecting surfaces 158 and 160, the second reflecting surface constituted by the convex reflecting surface 122 converts light incident through the opening 170 into parallel light. Even when the distance is close or when the distance between the opening 170 and the second reflecting surface is small, the light is transmitted to the first reflecting surface 1.
A wide range of 58 and 160 can be reflected. Therefore, opening 1
It is possible to reduce the distance between the first reflecting surface and the second reflecting surface 122, which is suitable for downsizing the optical scanner.

A gray tink lens 118 is provided around the convex reflection surface 122. The grating lens 118 is used for a barcode reader.
It is designed to function as a collimating lens, and is designed to function as a condenser lens for application to a confocal optical system.

Further, another grating lens 120 is provided around the grating lens 118, and the photodetectors 192 and 194 are provided on the movable plate 156 around the electrodes 158 and 160, respectively. . The grating lens 120 has a function of guiding incident light to the photodetectors 192 and 194. The photodetectors 192 and 194 are formed on a silicon substrate 186 constituting the base layer 174 of the movable plate 156 by a semiconductor manufacturing technique.

The grating lens 118 and the grating lens 120 are formed by micro-machining technology.
It is manufactured by processing a transparent film 114 formed of a silicon oxide film, a silicon nitride film, or polyimide. The grating lens 118 and the grating lens 120 manufactured in this manner have extremely high dimensional accuracy. Therefore, assembling can be easily performed as compared with a device in which the optical scanner 100 is combined with a separate optical element.

The step between the grating 118 and the grating lens 120 is 100 μm or less, depending on the performance of the lens. Therefore, the optical scanner 100
The device configuration can be made very small as compared with a device in which is combined with a separate optical element.

The configuration of this modified example is particularly suitable for a device for detecting scattered light, such as a scattered light detection type bar code reader, and can effectively detect light scattered on the surface to be measured.

The present invention is not limited to the above-described embodiment, but includes all embodiments carried out without departing from the gist thereof. Therefore, the following can be said about the optical scanner in the present embodiment.

(1) (Configuration) A movable plate provided with an opening through which light passes and a first reflection surface, a support for supporting the movable plate, And a second reflecting surface for reflecting the light toward the reflecting surface, wherein the thickness t of the opening satisfies the following conditional expression (1).

T ≦ d (cos α−R ^1/2 ) / sin α (1) where d is the opening diameter of the opening, α is the maximum deflection angle of the movable plate,
R is a desired ratio with respect to the light emission amount ratio from the opening when the movable plate has no deflection angle and when the movable plate has the maximum deflection angle. (Corresponding Embodiments of the Invention) The embodiments relating to the present invention correspond to everything described in the embodiments. (Function and Effect) The reflecting surface and the opening (pinhole) can be linearly arranged. In this optical scanner, components can be easily formed integrally, and compactness can be realized at low cost. However, in this configuration, since the opening is provided in the movable plate, there is a problem that the apparent opening area changes every moment with the vibration of the movable plate. A configuration in which the amount of light emitted from the aperture changes at the vibration position is not preferable as a characteristic of the optical scanner. In order to minimize this, the thickness of the opening must be sufficiently small with respect to the deflection angle. By defining the thickness by the formula, the change in the amount of emitted light when the movable plate vibrates can be minimized. Can be suppressed.

(2) (Configuration) The optical scanner according to the above (1), further comprising a light detecting section for detecting return light on the movable plate. (Corresponding Embodiment of the Invention) The embodiment relating to the present invention corresponds to the second modification. (Function and Effect) By forming the photodetector on the same plane as the movable plate having the reflection surface, the light scattered on the surface to be detected can be effectively detected.

(3) (Constitution) The lens further includes a lens disposed on an optical path of light scanned by the first reflection surface, wherein the movable plate, the support, the second reflection surface, and the lens are provided. The optical scanner according to the above (1) or (2), wherein is integrally formed. (Corresponding Embodiment of the Invention) The embodiment relating to the present invention corresponds to all the modifications described in the embodiment. (Function / Effect) By providing the lens, it is possible to process the light that is emitted to the outside while expanding to a desired light. For example, when this scanner is used for a barcode reader, a collimating lens may be used, or when this scanner is used for a confocal optical system, a condensing lens may be used, so that a wide range of versatility can be provided.

(4) (Structure) The movable plate is further provided with a divided electrode, and a ground electrode facing the divided electrode is further provided. The optical scanner according to any one of the above items. (Corresponding Embodiments of the Invention) The embodiments relating to the present invention correspond to everything described in the embodiments. (Function and Effect) The driving method using the electrostatic attraction is simple and suitable for a compact optical scanner. By using this, maximum compactness can be easily achieved.

(5) (Constitution) The above-mentioned (4), wherein an electrode surface provided on the movable plate is used as the first reflection surface, and an opening end of the opening is arranged on the electrode. Light scanner. (Corresponding Embodiments of the Invention) The embodiments relating to the present invention correspond to everything described in the embodiments. (Function and Effect) By forming the opening integrally with the formation of the electrode, the opening can be easily formed and the processing cost can be reduced.

(6) (Structure) The movable plate has a gimbal structure in which the natural frequency of the internal structure is different from that of the external structure. Optical scanner. (Corresponding Embodiment of the Invention) A third modification corresponds to an embodiment of the present invention. (Effects) When used in a confocal microscope or the like, an optical scanner capable of two-dimensional scanning is required. However, if a one-dimensional scanner is used in combination, compactness cannot be achieved. By employing the gimbal structure, it is possible to drive two-dimensionally with one movable plate, and it is possible to reduce the size as in the case of the one-dimensional type. Further, by giving a difference between the natural frequencies of the inner movable plate and the outer movable plate, damage to the outer movable plate in particular can be prevented.

(7) (Configuration) The optical scanner according to (3), wherein at least one grating lens is formed on the same plane. (Corresponding Embodiment of the Invention) The embodiment relating to the present invention corresponds to all the modifications described in the embodiment. (Operation and Effect) In order to achieve compactness, it is effective to use a grating lens that can be manufactured by micromachining. In the case of the configuration described in the third modification, lenses having different characteristics are formed on the same plane, so that light is efficiently emitted and scattered light is more efficiently condensed on the photodetector. Can be.

(8) (Configuration) The optical scanner according to (7), wherein the second reflection surface is formed on the same plane as the grating lens. (Corresponding Embodiment of the Invention) The embodiment relating to the present invention corresponds to all the modifications described in the embodiment. (Function and Effect) By forming the first reflecting surface on the same plane as the lens, the manufacturing is simplified, the cost is reduced, and
Can be made compact.

(9) (Configuration) The optical scanner according to (8), wherein the second reflection surface is a convex surface. (Corresponding Embodiment of the Invention) The embodiment relating to the present invention corresponds to a fourth modification. (Function and Effect) Since the second reflecting surface has a convex shape,
Even when light close to parallel light is used, the reflected light can effectively irradiate the reflecting surface on the movable plate.

[0078]

According to the present invention, there is provided an optical scanner in which the aperture, the second reflecting surface, and the first reflecting surface are arranged in a straight line, which can be reduced in size at low cost, and has little fluctuation in the amount of emitted light. You.

[Brief description of the drawings]

1A and 1B show an optical scanner according to an embodiment of the present invention, in which FIG. 1A is a cross-sectional view of the optical scanner, FIG. 1B is a top view of a reflection unit, and FIG.

FIG. 2 is a configuration diagram of a bar code reader using the optical scanner of FIG.

FIG. 3 is a diagram illustrating a state in which an apparent opening diameter changes according to a tilt of a movable plate.

FIG. 4 is a diagram illustrating a structure using an organic film applicable to a hinge of the optical scanner of FIG. 1;

FIG. 5 shows an optical scanner according to a first modification;
(A) is a cross-sectional view of the optical scanner, (B) is a top view of the reflection unit, and (C) is a top view of the scanner unit.

FIG. 6 shows an optical scanner according to a second modification;
(A) is a cross-sectional view of the optical scanner, (B) is a top view of the reflection unit, and (C) is a top view of the scanner unit.

FIG. 7 shows an optical scanner according to a third modification;
(A) is a cross-sectional view of the optical scanner, (B) is a top view of the reflection unit, and (C) is a top view of the scanner unit.

FIG. 8 is a sectional view of an optical scanner according to a fourth modification.

FIG. 9 shows a conventional bar code reader;
(A) is a front view of the bar code reader, (B) is a vertical sectional view along line 2-2 of (A), and (C) is a transverse sectional view along line 3-3 of (B).

[Explanation of symbols]

 116 Mirror 152 Support 154 Hinge 156 Movable plate 158, 160 Electrode 170 Opening

Claims (3)

[Claims] A movable plate provided with an opening through which light passes and a first reflecting surface; a support for supporting the movable plate; and a light passing through the opening on the first reflecting surface. An optical scanner having a second reflecting surface that reflects light toward the light source, wherein the thickness t of the opening satisfies the following expression (1). t ≦ d (cos α−R ^1/2 ) / sin α (1) where d is the opening diameter of the opening, α is the maximum deflection angle of the movable plate,
R is a desired ratio of the amount of light emitted from the opening when the movable plate has no deflection angle and at the maximum deflection angle. 2. The optical scanner according to claim 1, further comprising a light detector for detecting return light on said movable plate. 3. The apparatus according to claim 1, further comprising a lens disposed on an optical path of light scanned by said first reflection surface, wherein said movable plate, said support, said second reflection surface and said lens are formed integrally. The optical scanner according to claim 1, wherein the optical scanner is provided.