JP6974973B2 - Optical scanning measuring device - Google Patents

Description

The present invention relates to an optical scanning type measuring device that detects the shape and dimensions of an object and a passing position by optical scanning, and an image reading device using the same.

Conventionally, as an optical object measuring device, a device that performs optical scanning at a constant speed using a polygon mirror or the like, arranges an object to be measured in the scanning area, and measures the dimensions from the time when the scanning light is blocked. Yes (see Patent Document 1). In such a device, radial scanning light is converted into parallel light by a collimator lens and irradiated to an object to be measured, and the light passing through without being blocked is collected by the lens and detected by a photodetector.

On the other hand, in an image reading device such as a scanner, information on the shape dimensions of paper sheets and the amount of skew at the time of reading is required in order to accurately detect the frame of the scanned image and correct the skew, and the image is being conveyed. There is a need to precisely measure the width of the paper leaves and the change in the passing position of the edges of the paper leaves with respect to the image reading sensor. In recent years, in order to increase the speed and functionality of image readers, high-speed scanning is required to detect conveyed paper leaves by optical scanning, and the size of paper leaves is A3 paper from business cards and photographs. It is necessary to have a wide scanning area and high resolution that can accurately measure the amount of skew even for small sheets of paper.

As a device that enables high-speed scanning, there is a vibrating element in which the mirror portion is supported by a torsion beam. The vibrating element has a resonance frequency determined by the moment of inertia of the mirror portion and the spring constant of the torsion beam, and it is possible to obtain high-speed scanning and a large scanning angle by driving at this resonance frequency .

Japanese Unexamined Patent Publication No. 06-003116

[Miniaturization]
However, when the measuring device of Patent Document 1 is used as an image reading device, the device becomes large due to the wide measurement range, and optical parts such as lenses used in the optical system also need to be long and expensive. There is a problem of becoming.

[Constant velocity]
Even if a polygon mirror that rotates at an equal angular velocity is used, if the projection distance from the scanning center to the measurement position is shortened and the angle of view is increased in order to reduce the size and height of the device, an fθ lens or the like can be used. The problem arises that it becomes difficult to keep the moving speed of the beam spot at the measurement position constant, that is, to ensure constant velocity.

This problem of non-constant velocity becomes particularly remarkable when the vibrating element is driven at the resonance frequency for high-speed scanning. The scanning angle of the vibrating element changes in a sinusoidal manner with time, and the moving speed of the beam spot changes significantly when irradiating a non-measured object, which complicates the calculation of dimension calculation from the measured shading time. The error also increases. The effect of non-constant velocity is remarkable when the ratio of the scanning range used for detection to the entire scanning range of the vibration mirror is large, the projection distance is shortened due to the miniaturization of the measuring device, and a wide range. This is a particularly big problem when trying to scan. Although it is possible to obtain constant velocity by adding an arc sine lens or the like, it is not preferable because the number of expensive long lenses increases as the device becomes large.

An object of the present invention made in view of such a situation is that it is possible to measure the shape and dimensions of an object conveyed at high speed and the passing position with high accuracy by using a vibration mirror driven at a resonance frequency. Further, it is an object of the present invention to provide an optical scanning type measuring device capable of miniaturization.

The optical scanning type measuring device of the present invention for solving the above-mentioned problems includes an optical scanning means, a first optical system for converting scanning light into parallel light, a mask member having light-shielding portions formed at regular intervals, and the like. comprising the second optical system causing the condensing parallel light passing through the mask member, and a light detecting means for detecting the light condensed by the second optical system, the light detecting means for detecting using the number of light pulses, have rows measurements of the first and the object to be measured is between the second optical system, the light shielding portion of the mask member has a narrow width toward the end from the center of the optical scanning It is characterized by becoming.

As another aspect of the optical scanning type measuring device of the present invention for solving the above problems, an optical scanning means, a first optical system for converting scanning light into parallel light, and light-shielding portions at regular intervals are formed. The light detection includes a mask member, a second optical system that collects the parallel light that has passed through the mask member, and a light detection means that detects the light that is collected by the second optical system. Using the number of optical pulses detected by the means, the object to be measured between the first and second optical systems is measured, and the optical density of the transmissive portion of the mask member changes along the optical scanning direction. It is characterized by doing . Further, as another aspect of the optical scanning type measuring device of the present invention for solving the above problems, an optical scanning means, a first optical system for converting scanning light into parallel light, and light-shielding portions at regular intervals are formed. The mask member is provided with a second optical system for condensing the parallel light passing through the mask member, and a light detecting means for detecting the light condensed by the second optical system. Using the number of light pulses detected by the light detecting means, the object to be measured between the first and second optical systems was measured, and the second optical system had an uneven shape formed on the surface. It is composed of a sheet lens, and is characterized in that the light-shielding portion of the mask member and the uneven shape of the sheet lens are formed at the same pitch.
Further, as another aspect of the optical scanning type measuring device of the present invention for solving the above problems, an optical scanning means, a first optical system for converting scanning light into parallel light, and light-shielding portions at regular intervals are formed. The mask member is provided with a second optical system for condensing the parallel light passing through the mask member, and a light detecting means for detecting the light condensed by the second optical system. Using the number of optical pulses detected by the optical detection means, the object to be measured between the first and second optical systems is measured, and between the first optical system and the second optical system. , It is characterized by having a folded mirror.
Further, as another aspect of the optical scanning type measuring device of the present invention for solving the above problems, an optical scanning means, a first optical system for converting scanning light into parallel light, and light-shielding portions at regular intervals are formed. The mask member is provided with a second optical system for condensing the parallel light passing through the mask member, and a light detecting means for detecting the light condensed by the second optical system. Using the number of light pulses detected by the light detecting means, the object to be measured between the first and second optical systems is measured, and the first or second optical system is integrated with the mask member. It is characterized by having an uneven shape and light-shielding portions at regular intervals formed on the surface of the sheet lens.
Further, as another aspect of the optical scanning type measuring device of the present invention for solving the above problems, an optical scanning means, a first optical system for converting scanning light into parallel light, and light-shielding portions at regular intervals are formed. The mask member is provided with a second optical system for condensing the parallel light passing through the mask member, and a light detecting means for detecting the light condensed by the second optical system. Using the number of light pulses detected by the light detection means, the object to be measured between the first and second optical systems is measured, and an isosceles triangle-shaped guide arranged on the light detection means. It has a light body, and the light detecting means is arranged at a position away from the focal position of the second optical system with respect to the second optical system.

According to the optical scanning type measuring device of the present invention, since the mask member in which the light-shielding portions are formed at regular intervals is used, every time the beam spot moves by a fixed distance with respect to the movement of the beam spot due to the optical scanning. An optical pulse is detected at. Therefore, by counting the number of pulses, it is possible to measure the size and position of the object regardless of the moving speed of the beam spot, and high-speed and high-precision measurement can be performed using a vibration mirror driven at the resonance frequency. It will be possible. In addition, by using a sheet lens such as a Fresnel lens for the optical system that collects parallel light, and by arranging a light-shielding part of the mask member so as to block the light incident on the convex part at the same pitch as the surface uneven shape of the sheet lens. Stable light detection can be achieved by reducing the difference in the amount of transmitted light between the central portion and the peripheral portion of the sheet lens due to light eclipse. This makes it possible to reduce the size of the optical system and perform highly reliable measurement. In addition, by forming light-shielding portions on the sheet lens at regular intervals, the mask member and the condensing optical system can be integrated, reducing the number of expensive long optical components and reducing the size of the device. It will be possible.

It is a top view which shows the embodiment of this invention. It is a block diagram which shows the embodiment of this invention. It is a top view which shows the embodiment of this invention. It is a graph which shows the example of the detection signal by embodiment of this invention. It is a graph which explains the constant velocity property of a vibrating element. It is a top view which shows the embodiment of this invention. It is a graph which shows the example of the detection signal by embodiment of this invention. It is a top view which shows the embodiment of this invention. It is a top view which shows the embodiment of this invention. It is a top view which shows the embodiment of this invention. It is a top view which shows the embodiment of this invention. It is a top view which shows the embodiment of this invention. It is a top view which shows the embodiment of this invention.

Hereinafter, the present invention will be described in detail based on the embodiments.

[Device configuration]
FIG. 1 shows an optical scanning measuring device 1 according to an embodiment of the present invention. In the optical scanning type measuring device 1, the beam emitted from the laser light source 200 passes through the emission optical system 210 and is scanned by the vibrating element 10. The scanning light is converted into parallel light by the sheet lens 300 and is applied to the object to be measured 900 through the cover member 230. The scanning line formed through the cover member 230 is partially blocked by the object to be measured 900, and the passing scanning light is pulsed by the mask member 400 and converted into convergent light by the sheet lens 301, and the photo is taken through the light guide body 510. It is detected by the sensor 500. The light-shielding portions of the mask member 400 are arranged at the same pitch as the surface uneven shape of the sheet lens 301, and are arranged at positions that block the beam incident on the convex portions of the sheet lens 301. The photo sensor 500 is arranged at a position distant from the focal position of the sheet lens 301. Beam detectors (BD) 220 and 221 are arranged at positions of scanning angles wider than the scanning angle θeff in the range used for measurement.

FIG. 2 shows a signal processing means used in the optical scanning measuring device 1. The detection signal of the photosensor that detects the optical pulse is amplified and binarized, and the number of pulses is measured by the counter. The counter is reset and triggered based on the BD detection signal, and the measured count is converted into position information and output as object end position data. Further, the detection signals of the two BDs are converted into a binarized signal for measuring the scanning time between the two BDs by the signal processing circuit, and the scanning time is measured by the pulse width thereof. The vibration amplitude of the vibrating element is calculated from the measured scanning time, and the drive control circuit generates a drive signal for the vibrating element based on the difference between the measured value of the vibration amplitude and the target value, and the maximum scanning angle θmax is controlled to be constant. Will be done.

[Materials, etc.]
A vibrating element is used as the optical scanning means of the optical scanning measuring device of the present embodiment, which is preferable for miniaturization of the optical scanning means and high speed of optical scanning, but a rotating mirror such as a polygon mirror. It is also possible to use. A laser diode is used as the laser light source, and infrared light may be used as the beam wavelength in addition to visible light. A Fresnel lens or a diffractive lens can be used as the sheet lens, and the sheet lens is manufactured by forming a surface uneven shape with a mold on an acrylic resin or the like. Although not limited, the sheet lens is preferably a cylindrical lens from the viewpoint of ease of manufacture and cost. The mask member may be a transparent resin substrate such as glass, acrylic, or PET in which light-shielding portions are formed at regular intervals by vapor deposition or the like, or a metal plate in which openings are formed. When the pitch of the light-shielding part of the mask is fine in applications that require high resolution, precise alignment with the uneven shape of the sheet lens is required, and in order to prevent misalignment due to environmental changes, the sheet lens and mask member It is preferable to use the same material or a material having a similar coefficient of thermal expansion for the substrate. Glass or transparent resin formed into an isosceles triangle is used for the light guide, and the focusing angle of the focused light and the refractive index of the material used are adjusted so that the incident light is totally reflected inside and incident on the photosensor. Those designed at an appropriate angle are used accordingly.

[Vibration element]
FIG. 3 shows a vibration element 10 used in the optical scanning measuring device 1. The mirror portion 100 is arranged on the mirror portion base 120 supported by the torsion beams 110 and 111 so as to be rotationally vibrable. The torsion beam is held by the frame 130, and the mirror portion base 120, the torsion beams 110, 111, and the frame 130 are integrally formed. A magnet 140 is arranged on the back surface of the mirror portion, and rotational vibration is excited in the mirror portion by the action of a magnetic field generated by the yoke 150 wound around the coil 160 based on a drive signal.

In addition to silicon, materials such as metal and resin can be used for the torsion beam, and it is formed by processing a silicon wafer by a semiconductor process, press processing, injection molding, or the like. When a metal material is used, an aging-hardened Co—Ni-based alloy having a non-linearity of material properties, a small vibration damping rate, and a high fatigue limit is preferably used. It is preferable that the torsion beam and the frame are integrally formed, but the present invention is not limited to this, and a configuration in which the torsion beam and the frame are supported by separate members may be used. The mirror portion may be any as long as it can secure flatness and reflectance, and may be a silicon wafer or a mirror portion base on which a metal reflective film is formed. The magnet is preferably small and has a large magnetic force, and a neodymium magnet, a samarium cobalt magnet, or the like is preferably used.

The configuration of the vibrating element may be one in which a magnetic field is applied to the magnet in the mirror portion, or one in which a coil pattern is formed in the mirror portion and the magnet is arranged outside. Further, the vibration element is not limited to the electromagnetic drive, and may be a piezoelectric drive or an electrostatic drive type vibration element.

[Operating principle]
FIG. 4A shows an example of the photodetection signal of the photosensor 500. The horizontal axis indicates time, and the vertical axis indicates the magnitude of the photodetection signal, which is the detection signal when scanning from one scanning end to the other. Since the scanning light is pulsed by a mask having a light-shielding portion formed at regular intervals, a pulsed waveform appears in the photodetection signal every time the beam spot moves a predetermined distance (section A in the figure). While the scanning light is blocked by the object to be measured, the pulsed waveform does not appear (section B in the figure), and when the spot passes through the end of the object and the beam is detected again, the beam spot movement amount is calculated. The corresponding pulse waveform is observed (section C in the figure). FIG. 4B is a binarized light detection signal, and the number of pulses in the section A is proportional to the distance from one scanning end to one end of the object to be measured, and the distance is the mask member. It is obtained by multiplying the formation pitch of the light-shielding portion of the above by the number of pulses. Similarly, in the section C, the number of pulses corresponds to the distance from the other end of the object to be measured to the other scanning end. Of the pulses detected in the absence of the object to be measured, the number of pulses in the section B that does not appear due to the presence of the object to be measured corresponds to the width of the object to be measured in the scanning direction. In addition, if the object to be measured is conveyed at a constant speed in a direction orthogonal to the scanning direction, the object to be measured is continuously scanned and pulse measured to measure the two-dimensional shape of the object to be measured and to convey the object. It is possible to detect posture such as skewing of time. To measure the number of optical pulses, a threshold value is set for the signal of FIG. 4A and binarized, and a differential waveform of the optical detection signal of FIG. 4B is obtained to set the threshold value of the optical detection signal. It may be performed by a method of detecting a rising edge or a falling edge.

FIG. 5 shows the rate of change of the beam spot moving speed due to scanning of the vibrating element. The horizontal axis is the scanning angle, and the vertical axis is the rate of change of the moving speed based on the moving speed of the scanning center position. Graphs 1 to 5 in FIG. 5 are for when the maximum value θmax of the scanning angle is 35, 40, 45, 50, 55 degrees, respectively, and the angle θ where the moving speed becomes zero and the horizontal axis intersects with them. Equivalent to. Unless the angle range θeff used for measurement is small with respect to the maximum value θmax of the scanning angle, the constant velocity property of the vibrating element driven by utilizing resonance is not good. For example, considering the case where the maximum value θmax of the scanning angle in Graph 4 is 50 degrees, when 45 degrees out of 50 degrees is set as the angle θeff used for measurement, the moving speed of the spot accompanies the movement from the center to the scanning edge. Then, it once increases to about + 8% and starts to decrease, and then decreases to about -12% at the end of the measurement range. That is, a speed change of about 20% occurs during the measurement. The effect of such a speed change appears in the pulse period change of the photodetection signal in FIG. In the present invention, since the measurement is performed by measuring the number of pulses, highly accurate measurement is possible without being affected by this periodic change.

When the height of the measuring device is reduced and the size is reduced, it is necessary to increase the scanning angle θeff used for measurement. However, considering the load on the vibrating element, which is related to the durability of the element, the maximum value of the scanning angle θmax Is preferably kept as small as possible. Therefore, it is preferable to make the scanning angle θeff used for the measurement as large as possible among the maximum value θmax of the scanning angle, but this further reduces the constant velocity of the spot moving speed. For example, when the maximum value θmax of the scanning angle of the graph 4 is 49 degrees out of 50 degrees and the angle θeff is used for the measurement, the speed at the end of the measurement range is reduced to −50%. Even when the size is reduced in this way, the non-constant velocity is not affected if the measurement is performed by measuring the number of pulses. Further, since complicated signal processing and data calculation are not required only by measuring the number of pulses, high-speed measurement of an object can be performed by utilizing high-speed scanning of a resonance-driven vibrating element. INDUSTRIAL APPLICABILITY According to the present invention, it is possible to realize an optical scanning measuring device that is compact and capable of high-precision measurement during high-speed transportation.

Even when a polygon mirror that rotates at an equal angular velocity is used, if the projection distance from the scanning center to the measurement position is shortened and the angle of view is increased in order to reduce the size and height of the device, an fθ lens or the like can be used. Therefore, it becomes difficult to secure constant velocity, and the measurement by the pulse number measurement of the present invention is effective.

FIG. 6 shows an enlarged view of a mask member near the center of scanning and near the edges, and a sheet lens which is a condensing optical system. In the vicinity of the center of scanning in FIG. 6A, when there is no mask member, all parallel light, which is scanning light, is detected by being bent in the direction of the photo sensor. In the vicinity of the scanning end of FIG. 6B, when there is no mask member, light eclipse occurs due to the large undulations of the surface uneven shape of the sheet lens (light rays shown by the dotted line in the figure), which is detected by the photo sensor. The amount of light is reduced. FIG. 7 shows a light detection signal without a mask member as a curve T with respect to a light detection signal with a mask. The amount of beam light from the vicinity of the end is reduced due to eclipse with respect to the amount of beam light from the center of the sheet lens. On the other hand, if the light-shielding portion of the mask member is arranged so as to block the light incident on the convex portion of the sheet lens, the light ray shown by the dotted line in FIG. 6A near the center of the sheet lens is blocked, and the end portion of the sheet lens is blocked. In FIG. 6 (b) in the vicinity, the light beam that causes vignetting shown by the dotted line is blocked. As a result, the difference in the amount of light detected by the photo sensor near the center and near the edge is reduced. In this case, as shown in FIG. 7, the magnitude of the light detection signal of the light pulse reaches a plateau at the signal level M according to the ratio of the light-shielding portion to the pitch of the light-shielding portion of the mask member, and the difference in the detected light amount is suppressed. Be done. For example, if 80% of the incident light is reduced due to eclipse near the end of the sheet lens, the ratio of the light-shielding portion to the pitch of the light-shielding portion of the mask member is set to 80%, so that the beam from the entire scanning range is uniform. It becomes the amount of light. By appropriately forming the light-shielding portion of the mask member, it becomes easy to set the threshold value for binarization of the photodetection signal and the threshold value for rising / falling detection, and stable measurement becomes possible. According to the present invention using the sheet lens and the mask member, it is possible to effectively use the sheet lens which is advantageous for miniaturization and cost reduction of the apparatus.

FIG. 12 shows the configuration of the photodetector. A photosensor is arranged at a position distant from the focal position P of the sheet lens that converts parallel light into convergent light, and an isosceles triangle-shaped light guide is arranged on the light detection surface. Even when the direction of the beam deviates from the focal position due to the aberration of the sheet lens (L1 and L2 in FIG. 12), the light is focused and detected by the light guide. The angle of the isosceles triangle is set so that total reflection occurs inside the light guide with respect to the incident angle of the beam from the scanning end, depending on the refractive index of the light guide material. In order to reduce the size of the device, it is advantageous to use a sheet lens with a short focal length, but the shorter the focal length, the larger the aberration in the peripheral part, and the light receiving area of the photo sensor that detects the focused light. It will be necessary to use a large one. However, a photosensor having a large light receiving area cannot cope with measurement by high-speed scanning because of its large electric capacity and slow response speed. By arranging an isosceles triangle-shaped light guide on the light receiving surface of the photo sensor, both miniaturization and high-speed measurement can be achieved at the same time.

[Other embodiments]
FIG. 8 shows an embodiment in which the groove of the sheet lens is fine with respect to the width of the light-shielding portion of the mask member. FIG. 8A is an enlarged view of the vicinity of the center of the sheet lens, and FIG. 8B is an enlarged view of the vicinity of the end portion. In the optical scanning type measuring device 1 of FIG. 1, the light-shielding portion of the mask member has a configuration having the same pitch as the surface uneven shape of the sheet lens, but the configuration is not limited to this, and the configuration is as shown in FIG. Is also good. In the configuration of FIG. 8, in the region where the uneven shape near the center of the sheet lens of FIG. 8A has small undulations and little eclipse, the ratio of the light-shielding portion to the light-shielding portion pitch of the mask member is increased, and the sheet of FIG. 8B is formed. The ratio of the light-shielding portion to the light-shielding portion pitch of the mask member is set small in the region where the uneven shape near the lens end is large and eclipsed. That is, the light-shielding portion is formed so that the proportion of the light-shielding portion of the mask member decreases from the center to the end of the sheet lens. As a result, the beam from the entire scanning range has a uniform amount of light, and stable measurement is possible. Further, as shown in FIG. 8E, the width of the light-shielding portion may be constant and the optical density of the transmission portion may be changed. The optical density of the transmission portion is set high in the region where vignetting is low near the center of the sheet lens in FIG. 8 (c), and the optical density is set low in the region where vignetting is high near the end of the sheet lens in FIG. 8 (d). This also ensures that the beam from the entire scanning range has a uniform amount of light, enabling stable measurement. Here, similarly, a mask member having a constant light-shielding portion width and an optical filter whose optical density is reduced from the scanning center portion toward the end portion may be configured as separate members.

FIG. 9 shows an optical scanning measuring device 2 which is another embodiment of the present invention. A folded mirror 250 is arranged on the back surface of the mask member 410, and a lens that converts scanning light into parallel light and a lens that converts parallel light into convergent light are shared. A lens member 240 is arranged to separate the reciprocating optical path, and the object to be measured 900 is moved to the mask member side for detection in order to prevent a decrease in measurement resolution in the transport direction due to an optical path difference. According to this configuration, it is possible to reduce the height of the measuring device, which is effective when the arrangement space on one side of the object to be measured cannot be secured. In the configuration of FIG. 9, a reflective portion may be formed on the mask member to integrate the mask member and the folded mirror. In this case, a reflective portion that folds back parallel light is formed in the region of the transmissive portion of the mask member, and the region of the light-shielding portion is replaced with a transmissive portion or a light absorption portion. A metal film such as Au, Ag, or Al is formed on the base material of the mask member in the reflective portion.

FIG. 10 shows an optical scanning measuring device 3 which is another embodiment of the present invention. The configuration is the same as that shown in FIG. 1 except that the mask member is eliminated by adding the mask function to the sheet lens 302. The sheet lens 302 has a flat surface having a convex portion having an uneven surface on a normal sheet lens, and a light-shielding material is applied to the flat portion by transfer or the like. The configuration is not limited to this as long as it interferes with the light transmission of the convex portion, and a flat surface may be roughened. When the sheet lens and the mask member are separate parts, especially when it is necessary to align the light-shielding part of the mask member so as to block the light incident on the convex portion of the sheet lens, it takes time to adjust, and the sheet lens and the mask also take time. If the material of the member is different and the coefficient of thermal expansion is different, the position may shift due to the environmental change. If the sheet lens and the mask member of the present embodiment are integrated, stable measurement is possible regardless of changes in the environment.

FIG. 11 shows an optical scanning measuring device 4 which is another embodiment of the present invention. A curved mirror is used as an optical system for converting scanning light into parallel light, and the scanning optical system may have such a configuration. The detection optical system is the same as in FIG. In addition to a curved mirror having a reflective film formed on a resin mold, a curved mirror may be held on a curved surface in an elastically deformed state by using a polished mirror-surfaced metal plate or a thin glass plate on which a reflective film is formed. good. The glass plate can easily form a mirror surface, and if a glass ribbon with a thickness of several tens of μm and an R shape formed on the end face by melting treatment is used, it will not be damaged even if it is deformed and held on a curved surface, and it is cheaper. A scanning optical system can be configured.

(Example)
FIG. 13A shows an image reading device 5 which is an embodiment of the present invention. In this embodiment, the above-mentioned optical scanning measuring devices are arranged side by side in a line sensor shape to reduce the height of the image reading device. The optical scanning type measuring devices may be arranged side by side in the optical scanning direction as shown in FIG. 13 (b), or may be arranged so as to be displaced in the transport direction as shown in FIG. 13 (c). According to the arrangement of FIG. 13C, even when a plurality of optical scanning measuring devices are arranged in a line sensor shape, there is no undetectable region at the joint between the measuring devices, and the entire width of the transport path is not formed. Can be measured with. The optical scanning of the optical scanning measuring devices arranged side by side is performed synchronously, and the paper sheets transported at the same time interval are measured.

In the image reading device 5, the paper sheets 910 are transported at high speed in the transport path 820 by the rotation of the transport roller, and the width of the paper leaves passing through by the optical scanning measuring device and the width of the transport path with respect to the width of the paper leaves at both ends. The passing position is continuously measured, and the two-dimensional shape dimension of the paper sheet and the posture during transportation, that is, the amount of skew is detected. Images on both sides of the paper sheets that have passed through the optical scanning measuring device are captured by the image reading sensors 800 and 801. The paper sheets for which the image has been read are conveyed by the transfer roller and discharged to the upper part of the image reading device. In the captured image, the part where the background other than the paper leaves is reflected is cut out based on the shape and dimensional measurement results of the optical scanning measuring device, and the skew correction is performed based on the detection result of the skew amount and stored. It is stored in a medium or the like.

Since the image reading device of the present embodiment uses the optical scanning type measuring device of the present invention, high-speed and high-precision dimensional measurement is possible, and accurate image cutting is possible even when paper sheets are conveyed at high speed. , Skew correction is possible. INDUSTRIAL APPLICABILITY According to the present invention, an image reading device having excellent reading speed and reading performance can be realized.

1, 2, 3, 4 Optical scanning measuring device 5 Image reading device 10 Vibrating element 100 Mirror section 110, 111 Twisting beam 120 Mirror section base 130 Frame 140 Magnet 150 Yoke 160 Coil 200 Laser light source 210 Ejection optical system 220, 221 Beam Detector 230 Cover member 240 Lens member 250 Folded mirror 270 Curved mirror 300, 301, 302 Sheet lens 400, 401, 402 Mask member 500 Photosensor 510 Light guide 700 Signal processing means 800, 801 Image reading sensor 810 Conveyor roller 820 Conveyance path 900 Measured object 910 Paper leaves

Claims (12)

Optical scanning means and
A first optical system that converts scanning light into parallel light,
A mask member with light-shielding parts formed at regular intervals,
A second optical system that collects the parallel light that has passed through the mask member, and
A photodetecting means for detecting the light focused by the second optical system is provided.
Using light pulses to the light detecting means detects, it has rows measurement of the object located between the first and the second optical system,
The light-shielding portion of the mask member is an optical-scanning type measuring device characterized in that the width becomes narrower from the center to the end of the optical scanning. Optical scanning means and
A first optical system that converts scanning light into parallel light,
A mask member with light-shielding parts formed at regular intervals,
A second optical system that collects the parallel light that has passed through the mask member, and
A photodetecting means for detecting the light focused by the second optical system is provided.
Using the number of optical pulses detected by the photodetecting means, the object to be measured between the first and second optical systems is measured.
The transmissive portion of the mask member, an optical scanning measuring device you characterized in that the optical density along the light scanning direction changes. Optical scanning means and
A first optical system that converts scanning light into parallel light,
A mask member with light-shielding parts formed at regular intervals,
A second optical system that collects the parallel light that has passed through the mask member, and
A photodetecting means for detecting the light focused by the second optical system is provided.
Using the number of optical pulses detected by the photodetecting means, the object to be measured between the first and second optical systems is measured.
The second optical system is composed of a sheet lens having an uneven shape formed on its surface.
The uneven shape of the light shielding portion of the mask member and the sheet lens optical scanning measuring device you characterized in that it is formed in the same pitch. The optical scanning measuring device according to claim 3 , wherein the light-shielding portion of the mask member is arranged so as to shield the convex portion of the concave-convex shape of the sheet lens. Optical scanning means and
A first optical system that converts scanning light into parallel light,
A mask member with light-shielding parts formed at regular intervals,
A second optical system that collects the parallel light that has passed through the mask member, and
A photodetecting means for detecting the light focused by the second optical system is provided.
Using the number of optical pulses detected by the photodetecting means, the object to be measured between the first and second optical systems is measured.
Between the second optical system and the first optical system, an optical scanning measuring device you further comprising a folding mirror. The optical scanning type measuring device according to claim 5 , wherein the first optical system and the second optical system are the same optical system. The optical scanning type measuring device according to claim 5 or 6 , wherein the mask member is integrally formed on the folded mirror, and a light-shielding portion that does not generate reflected light is formed at regular intervals. Optical scanning means and
A first optical system that converts scanning light into parallel light,
A mask member with light-shielding parts formed at regular intervals,
A second optical system that collects the parallel light that has passed through the mask member, and
A photodetecting means for detecting the light focused by the second optical system is provided.
Using the number of optical pulses detected by the photodetecting means, the object to be measured between the first and second optical systems is measured.
The first or second optical system, the mask member is made of sheet lens formed integrally, that the optical scanning you wherein the uneven shape and the light shielding portion of the predetermined interval is formed on the surface measuring device. Optical scanning means and
A first optical system that converts scanning light into parallel light,
A mask member with light-shielding parts formed at regular intervals,
A second optical system that collects the parallel light that has passed through the mask member, and
A photodetecting means for detecting the light focused by the second optical system is provided.
Using the number of optical pulses detected by the photodetecting means, the object to be measured between the first and second optical systems is measured.
It has an isosceles right triangle-shaped light guide arranged on the photodetecting means, and has an isosceles right triangle shape.
Said light detecting means, the second said relative optical system of the second optical system optical scanning measuring device that you wherein disposed in a position away from the focal position of the. The optical scanning type measuring device according to any one of claims 1 to 9 , wherein the optical scanning means is a vibrating element driven in the vicinity of a resonance frequency. The optical scanning measuring apparatus according to any one of claims 1 to 10 , wherein the object to be measured passing between the first and second optical systems is continuously measured. An image reading device comprising the optical scanning measuring device according to any one of claims 1 to 11.

Images