Abstract: A movable table system comprising two identical tables on a common rail arrangement having a linear rail region underneath a detection unit and a processing unit, and therefore the tables can be alternatingly moved in a straight line along the common rail arrangement, in the same table-movement direction, fully underneath the detection unit and processing unit, and can be independently controlled by a computer unit. The movable table system provides a new option for processing planar workpieces, in which a particularly high throughput rate and improved precision can be achieved using merely one processing unit.

Abstract: An image forming system which, even when overprinting is made on a sheet processed by an external device, prevents misregistration of the image formed on the sheet, and a control method for the image forming system, and a non-transitory computer-readable recording medium storing a program. The image forming system includes an image forming device, an image reader, an arithmetic processor, and a controller. The arithmetic processor calculates the information on shrinkage which occurs in the sheet when the sheet is subjected to a treatment process by the external device, as external shrinkage information. The controller calculates an image correction value according to the external shrinkage information. The image forming device forms an image according to the image correction value when forming the image on the processed sheet.

Abstract: An optical scanning device that scans a photoreceptor with light, the device includes: a light emitter that emits light according to a supply current amount; a source-side optical system that includes an optical element corresponding to the light emitter, the optical element transmitting and shaping the light emitted from the corresponding light emitter; a polygon mirror that cyclically deflects the light shaped by the source-side optical system; an image-side optical system that condenses the light deflected by the polygon mirror on a surface of the photoreceptor; a motor that rotates the polygon mirror; and a light source controller that: monitors a temperature of the optical element; and adjusts the supply current amount for the light emitter or adjusts the temperature of the optical element corresponding to the light emitter to make a temperature difference between the light emitter and the corresponding optical element fall within an allowable range.

Abstract: An image forming apparatus including a polygon mirror that deflects a light beam, the image forming apparatus includes: an optical sensor arranged such that the light beam deflected by the polygon mirror enters the optical sensor; and a hardware processor that measures an output level of the optical sensor and calculates, as a remaining life of the polygon mirror, an operation time of the polygon mirror to when the output level becomes a threshold value in a case of assuming that the output level ongoingly changes at a rate of change over time that is a change amount of the output level per unit operation time of the polygon mirror, using the measured output level.

Abstract: It is desired to reduce deformation of reflecting surfaces of a rotatable polygon mirror that is formed by using resin molding. The rotatable polygon mirror that is formed by resin molding is provided with recesses.

Abstract: An image forming apparatus includes: a photoreceptor; a light source; a rotational polygon mirror including a plurality of mirror surfaces on an outer circumferential surface of a rotating body; and a hardware processor that: controls the light source to perform emission of a light beam; controls to rotate the rotational polygon mirror to perform a sequential primary scanning; and corrects a shift of an exposure position of the light beam; and a clock characteristic changer capable of changing a clock characteristic including at least one of frequency and phase of a write clock, wherein the hardware processor controls to execute two-dimensional exposure with the clock characteristic of the write clock, controls to execute the two-dimensional exposure at a predetermined relative position with respect to the mirror surface, and specifies a mirror surface used for formation of each portion of the detection pattern.

Abstract: An optical scanning apparatus includes a light source to emit light, a light deflector having a reflection face to deflect the light as a scan-use light to scan an image generation element by oscillating the reflection face, a light receiving element to receive a control-use light to generate a signal used for controlling a scanning condition of the scan-use light, and a control unit to control the scanning condition of the light deflector based on the generated signal.

Abstract: An image forming apparatus includes: a rotating polygonal mirror having reflection surfaces, and to reflect a luminous flux at each reflection surface so as to scan a photosensitive member; a detection unit configured to detect the luminous flux; a measurement unit configured to measure an interval between time points at which the detection unit detects the luminous flux; a storage unit configured to store correction value data for correcting an image signal for each reflection surface relative to a reference reflection surface; and a specification unit configured to select a characteristic value from among a plurality of values that are obtained from results of measurements, and to specify the reference reflection surface based on the characteristic value. The plurality of values include results of predetermined operations performed on two or more intervals measured by the measurement unit.

Abstract: An information processing apparatus is provided with a specifying unit, an output control unit, and an event detecting unit. The specifying unit specifies an operator who inputs an output request for outputting an output object. The output control unit controls an output process in accordance with the output request. The event detecting unit detects an event having a possibility that the operator stops immediate output of the output request. Even in a case where the output control unit is instructed from the operator to perform an immediate output process of the output request when the operator is specified and where the operator is specified, the output control unit stops the immediate output process of the output request in a case where the event detecting unit detects the event.

Abstract: A light source array includes a first group of light sources having laser elements and a second group of light sources having laser elements. A first laser driver drives the laser elements and a second laser driver drives the laser elements. The first group of light sources and the second group of light sources execute multiple exposure. For example, the second group of light sources executes a first exposure and the first group of light sources executes a second exposure. In other words, the first group of light sources and the second group of light sources are driven by the first laser driver and the second laser driver, respectively, so as to expose the same position.

Abstract: The rotary body driving apparatus comprises: a rotary body having reflective surfaces; a motor having a rotor shaft; a rotor being attached to one end part of the rotor shaft together with the rotary body; a stator housing having a bearing section, which rotatably holds the rotor shaft; a motor substrate for detecting a rotational position of the rotor, the motor substrate being provided to the stator housing; a magnetized section for frequency generation, the magnetized section being formed into a ring shape and provided to an end surface of the rotary body facing the motor substrate; and a circular frequency generation pattern, which faces the magnetized section, being provided to the motor substrate and disposed close to the magnetized section.

Abstract: A light scanning unit includes a light source to emit a light beam; a polygonal mirror to deflect the light beam in a main scanning direction; and an imaging optical system to image the light beam onto a scanning surface. The polygonal mirror includes a plurality of reflection surfaces that are formed in an outer portion of the polygonal mirror and rotate around a rotational axis and an internal mirror surface that defines a hole. A ratio of an internal diameter d to an outer diameter D satisfies 0.1?d/D?0.3. The polygonal mirror is adhered to a motor unit that supports and rotates the polygonal mirror, using an adhesive. The internal mirror surface of the polygonal mirror defining the hole is point-bonded to the motor unit using the adhesive, and the point-bonding is conducted in a direction toward a corner of the reflection surfaces.

Abstract: An image forming apparatus includes the following. An image forming unit forms an image. An image magnification changing unit changes a rotating speed of a polygon motor to change magnification of the image. A reference position detecting unit detects a reference position of a predetermined target component in a vertical scanning direction. A target component position calculating unit calculates a position of the target component based on a detecting result and a signal of a predetermined cycle according to the rotating speed of the polygon motor. A storage unit stores a correction table to correct density unevenness. An image data correcting unit obtains correction data based on the position of the target component and corrects the image data. A parameter correcting unit corrects a parameter according to a timing that the rotating speed of the polygon motor is changed.

Abstract: The rotary body driving apparatus comprises: a rotary body having a plurality of reflective surfaces; a rotor being attached to a rotor shaft together with the rotary body; a stator housing having a bearing section; a motor substrate for detecting a rotational position of the rotor; a circular magnetized section for frequency generation facing the motor substrate; a circular frequency generation pattern, which faces the magnetized section, being provided to the motor substrate and disposed close to the magnetized section; a position detecting section, which corresponds to a reference reflective surface of the rotary body, being radially outwardly or inwardly projected from a part of the magnetized section; and a magnetic sensor, which faces the position detecting section, being provided to the motor substrate.

Abstract: An image forming apparatus includes a driving unit configured to drive a light-emitting element for emitting a laser beam; a rotational polygon mirror scans a photosensitive member with the laser beam. The driving unit executes a first adjustment for causing the light-emitting element to emit light at a first light emission intensity to adjust a first driving current, and a second adjustment for causing the light-emitting element to emit light at a second light emission intensity to adjust a second driving current. During a time period after the polygon mirror has started rotating until a predetermined speed is reached, the driving unit performs the first adjustment and the second adjustment, after the polygon mirror has started rotating and before performing the first adjustment, performs the second adjustment.

Abstract: An optical scanning device includes a housing, a polygon mirror, and a motor. The polygon mirror is disposed in the housing and reflects light incident thereon while being rotated. The motor is disposed in the housing and rotates the polygon mirror. The housing has a cooling passage that cools the interior of the housing. The cooling passage is asymmetrically located relative to a rotation shaft of the motor in a cross section perpendicular to the main scanning direction.

Abstract: A system and method for reducing scan line jitter caused by facet cut variation in scan systems employing a plurality of laser sources and a sensor for generating the timing for the laser sources. The system includes a controller for determining a unique time delay for each facet of the rotating mirror, and controlling the laser sources so that video provided by each laser source is delayed in a scan line by the unique time delay corresponding to the facet of the rotating mirror used in creating the scan line.

Abstract: An optical writing device includes a light source, an optical deflector that deflects and scans light from the light source, a pre-deflector optical system that guides the light from the light source to the deflector, a post-deflector optical system that guides the scanned light to a target surface, a cover covering the deflector and including a first opening and a second opening provided at different positions, and a housing housing these optical elements. Light traveling from the light source to the deflector and the light scanned by the deflector are transmitted through the first opening but not through the second opening. During the rotation of the deflector, a forced inflow of air flowing from outside to inside the cover is generated in the first opening, and a discharged airflow flowing from inside to outside the cover is generated in the second opening.

Abstract: An optical scanning apparatus includes a light source; and a rotational polygon mirror having N reflecting surfaces, the rotational polygon mirror being configured to reflect a light flux emitted from the light source so that a scanning surface is scanned along a main-scanning direction with reflected from the rotational polygon mirror. A width of the light flux incident on the rotational polygon mirror in a direction corresponding to the main-scanning direction is smaller than a width of each reflecting surface of the rotational polygon mirror in the direction corresponding to the main-scanning direction.

Abstract: An image forming apparatus includes a light source which illuminates in response to image data, and a deflector to deflect an optical beam output from the light source into a scanning beam running along a main scanning line across an image forming area in a main scanning direction. There are plurality of beam detectors to detect the scanning beam at a plurality of different positions along the main scanning line, the plurality of beam detectors including first and second beam detectors detecting the scanning beam at positions in front-end and rear-end sides, respectively, in the main scanning direction.

Abstract: An optical scanning device including a controller configured to control a light emitter to emit a first light beam in accordance with a first pattern, control the light emitter to emit a second light beam in accordance with a second pattern, discriminate between a first signal output from a sensor in accordance with the first pattern and a second signal output from the sensor in accordance with the second pattern, identify a first moment at which the discriminated first signal has been output and a second moment at which the discriminated second signal has been output, and determine a moment to start forming on a scanned object a first scanning line by the first light beam, based on the identified first moment, and determine a moment to start forming on the scanned object a second scanning line by the second light beam, based on the identified second moment.

Abstract: An image forming apparatus includes a control unit performing a first rotation control process of switching on and off current-supplying in accordance with a change in a first deviation between a first rotation speed of a brushless motor and a target speed regardless of a change in an integrated value of the first deviation; a second rotation control process of calculating an integrated value of a second deviation between a second rotation speed of the brushless motor and the target speed, and switching on and off the current-supplying in accordance with a change in the second deviation and a change in the integrated value of the second deviation; and a rotation control switching process of switching to the second rotation control process when it is determined that the first deviation has entered a prescribed range during the first rotation control process.

Abstract: An image forming apparatus includes a temperature sensor detecting an operating ambient temperature of the polygon motor, and a controller controlling the polygon motor and the paper feed mechanism. If the temperature detected by the temperature sensor is equal to or greater than a preset temperature, the controller controls, before operation for giving a command to start image formation is performed, the polygon motor to rotate; increases, in response to the operation, a rotational speed of the polygon motor up to a rated speed; and controls the paper feed mechanism to start conveying a sheet of paper at a time when a period of time variable depending on the detected temperature has elapsed, the period of time being preset to be shorter as the detected temperature increases, in expectation of a time required for the rotational speed of the polygon motor to reach the rated speed.

Abstract: An optical scanning device includes a housing, a laser light source outputting a laser light, a polygon mirror arranged in an arrangement space and deflecting the laser light to scan a predetermined object with the laser light while rotating, a polygon motor rotating the polygon mirror, a control board arranged in the arrangement space and controlling the polygon motor, and a flow-control member arranged in the arrangement space and guiding an airflow generated by a rotation of the polygon mirror to an outside of the arrangement space to circulate the airflow within the housing.

Abstract: A light beam emission apparatus separates, via a half mirror, apart of a laser beam emitted from a semiconductor laser towards a photosensitive member, guides the separated laser beam to an optical sensor to detect a light quantity, and controls the light quantity based on the detected result. The light beam emission apparatus includes a first light blocking member located between the semiconductor laser and the half mirror, and a second light blocking member located between the half mirror and the optical sensor.

Abstract: An optical scanning device includes a pre-deflection optical system including a first optical element that adjusts the shape of beams emitted from the light source; and a second and third optical elements arranged such that the second optical element is arranged closer to the light source than the third optical element is. Both of the second and third optical elements have no refracting power in the deflection scanning direction and have positive refracting power only in a direction perpendicular to the deflection scanning direction. An interval between scanning lines formed on the scanned area and a deviation of the scanning-line interval between scanning positions are adjusted by displacement of the second and third optical elements in a direction of an optical axis of the pre-deflection optical system and displacement of at least one of the second and third optical elements in the direction perpendicular to the deflection scanning direction.

Abstract: An optical scanning device has a light deflector deflecting a light beam from a light source, a synchronization detection sensor determining timing of starting scanning in main scanning direction based on timing of detecting the light beam scanned in main scanning direction by the light deflector, and a pre-sensor imaging optical system imaging the light beam reflected from the light deflector on the synchronization detection sensor. The pre-sensor imaging optical system moves the imaging position of the light beam on the synchronization detection sensor in a direction making the timing of detecting the light beam earlier or later according to whether variation in temperature causes the magnification of the scanning optical system in main scanning direction to increase or decrease respectively.

Abstract: An optical writing device includes a light source, an optical deflector that deflects and scans light from the light source, a pre-deflector optical system that guides the light from the light source to the deflector, a post-deflector optical system that guides the scanned light to a target surface, a cover covering the deflector and including a first opening and a second opening provided at different positions, and a housing housing these optical elements. Light traveling from the light source to the deflector and the light scanned by the deflector are transmitted through the first opening but not through the second opening. During the rotation of the deflector, a forced inflow of air flowing from outside to inside the cover is generated in the first opening, and a discharged airflow flowing from inside to outside the cover is generated in the second opening.

Abstract: An image forming apparatus includes an image forming unit which transfers an image obtained through exposure and development to paper, and a control unit which changes a rotation speed of a polygon mirror at an intermediate area on a carrier to change a reduction/magnification ratio of an image. The control unit changes the rotation speed in a stepwise manner in such a way as to allow a stable rotation of the polygon mirror in each step, and controls the image forming unit to form a corrected patch image in parallel with the stepwise change of the rotation speed. The corrected patch image is obtained through correction in accordance with the stepwise change of the rotation speed to be the same as the patch image formed when the rotation speed is not changed.

Abstract: The image forming apparatus includes a determination unit configured to determine whether or not a polygon mirror has converged to the number of rotations that allows image formation to be performed, and the determination unit is capable of detecting a first timing and a second timing and determines that the polygon mirror has converged to a number of rotations that allows the image formation to be performed based on an earlier one of the first timing and the second timing.

Abstract: An optical scanning device includes: a light source unit; a light deflecting unit that deflects a light beam emitted from the light source unit; a scanning optical device that focuses the light beam deflected by the light deflecting unit on a scanned surface; and a light shielding member. The scanning optical device is provided in a direction in which a sound pressure level of a noise caused by rotation of a rotating polygon mirror included in the light deflecting unit is highest.

Abstract: The calculation unit calculates the time interval between the time at detecting the light beam reflected by the reflective surface of the rotatory polyhedron incident on the BD sensor by the light beam detecting unit and the time at detecting the light beam reflected by the reflective surface incident on the optical sensor in the light source by the return light beam detecting unit. The scan adjusting unit adjusts the luminescence time of the light source for scanning the light beam on the surface to be scanned based on the time interval calculated by the calculation unit.

Abstract: If inclination correction of scanning line is performed while the incident position of the laser beam is not suitable, the shape of a spot of the laser beam which forms an image on a photosensitive drum may not be uniform depending on the scanning position of the laser beam. The housing is provided with a U-shaped groove to which the convex portion of a lens hold member that holds the lens is engaged. With the position of the convex portion adjusted, the convex portion is attached and secured in the U-shaped groove. Thus, the installation position of the lens to an optical path of the laser beam is adjusted, and the lens can be rotated and adjusted in order to correct an inclination or a bending of scanning line.

Abstract: A light scanning unit and an electrophotographic image forming apparatus employing the same. The light scanning unit includes an imaging optical system including, when a path of one of the light beams directed to one of the surfaces disposed relatively far from the deflector is referred to as a first light path and when a path of one of the light beams directed to one of the surfaces disposed relatively close to the deflector is referred to as a second light path, light paths in which both of a section of the second light path before a first change of the second light path and a section of the second light path after the first change of the second light path intersect a section of the first light path after a second change of the first light path.

Abstract: An image forming apparatus including a plurality of developers and optical scanners, each of the optical scanners having a light source and a light reflecting unit and forming an electrostatic latent image on a photo conductor of each of the developers. The optical scanners have the same focusing distance from the light source to the photo conductor. The light reflecting unit of one of the optical scanners is arranged at a position different from the light reflecting unit of another optical scanner, such that intervals between the developers vary. The plurality of developers include a yellow (Y) developer, a magenta (M) developer, a cyan (C) developer, and a black (K) developer. The optical scanners include a first optical scanner, which forms electrostatic latent images on two of the developers including the black (K) developer, and a second optical scanner, which forms electrostatic latent images on the other two developers.

Abstract: An optical scanning device includes a rotating polygon mirror, a motor, a substrate, a heat releasing member and a heat transfer member. The rotating polygon mirror deflection scans light emitting by a light source. The motor rotatively drives the rotating polygon mirror. The substrate has a drive circuit part for controlling the motor. The heat releasing member releases heat generated from the substrate. The heat transfer member is sandwiched between the substrate and the heat releasing member to be compressively deformed. A receiving portion that part of the heat transfer member compressively deformed enters is formed in a first part of the heat releasing member in which the heat transfer member is provided.

Abstract: The image forming apparatus includes a determination unit configured to determine whether or not a polygon mirror has converged to the number of rotations that allows image formation to be performed, and the determination unit is capable of detecting a first timing and a second timing and determines that the polygon mirror has converged to a number of rotations that allows the image formation to be performed based on an earlier one of the first timing and the second timing.

Abstract: A polygon mirror assembly, a light scanning unit employing the polygon mirror assembly, and an image forming apparatus. The polygon mirror assembly includes a polygon mirror formed of a plastic material and having a plurality of reflection surfaces; and a motor unit to support and rotate the polygon mirror, where the polygon mirror is coupled to the motor unit by using an adhesive material.

Abstract: An optical scanning device scanning scan target surfaces in a first direction with light includes: a light source emitting first and second light beams corresponding to two of the scan target surfaces; an optical deflector including a reflection surface on which the emitted first and second light beams are obliquely incident while being separated from each other in a second direction perpendicular to the first direction, and deflecting the first and second light beams; a scanning lens disposed on respective optical paths of the deflected first and second light beams; and a branching optical element transmitting therethrough most of the first light beam transmitted through the scanning lens, and reflecting most of the second light beam transmitted through the scanning lens. The deflected first and second light beams intersect between the optical deflector and the branching optical element, when projected on a plane perpendicular to the first direction.

Abstract: An image forming device includes an exposure device configured to emit exposure light and an air flow generator configured to generate an air flow. The exposure device includes a heat source that generates heat and a heat sink configured to dissipate the heat. The heat sink includes a plurality of fins located inside the air flow. The plurality of fins extend in a direction parallel to a direction where the air flow flows and are arrayed in a direction orthogonal to the direction where the air flow flows. The plurality of fins are formed so as to increase in height from an upstream side toward a downstream side in the direction where the air flow flows.

Abstract: A scanning system for use in an imaging apparatus includes a mirror assembly having a rotating mirror with a plurality of facets, a motor operatively coupled to the rotating mirror and closed loop control circuitry coupled to the motor. The mirror assembly generates a lock signal indicative of whether or not the motor is substantially at a target speed. A controller is communicatively coupled to the mirror assembly for controlling rotation of the rotating mirror, the controller generating a reference signal received by the motor assembly indicating the target speed for the rotating mirror. The reference signal is varied based at least in part upon an acceleration profile that accelerates the motor so that overshoot of the target speed is substantially reduced.

Abstract: A light scanning device includes an optical unit. The optical unit includes a polygon mirror and a polygon motor. The polygon mirror includes n (n is an integer equal to or larger than 1) mirror surfaces and guides light in a main scanning direction of an image bearing member. The polygon motor includes m (m is an integer equal to or larger than 1 and is coprime with n) poles and rotates the polygon mirror.

Abstract: At the time of forming an image, a rise in a temperature of a drive motor generates distortion in a bottom of a optical box of an optical scanning apparatus. If an opening is formed on the optical box to release heat, the optical box becomes easily distorted. To solve such a problem, according to the present invention, the optical scanning apparatus includes a rib which crosses over the opening formed at the bottom of the optical box.

Abstract: An optical writer includes a housing, a light source, a deflector, and a plurality of optical elements. The housing includes a plurality of surfaces, one of which includes a substantially flat portion having an opening formed therein and a curved portion curved in the shape of an arc of a circle in cross-section. The light source is enclosed within the housing and projects light through the opening and onto a target. The deflector is enclosed within the housing and deflects the light projected from the light source in a main scanning direction. The plurality of optical elements is enclosed within the housing and directs the light deflected by the deflector onto the target.

Abstract: An optical scanning device includes a light source that emits a laser beam, a deflector that deflects the emitted laser beam, a scanning lens that causes the deflected laser beam to scan a surface of a photosensitive body at a uniform velocity, a reflector having a reflective surface that reflects the deflected laser beam toward the photosensitive body among the laser beams that have passed through the scanning lens, and a synchronization sensor that receives the laser beam from the reflector and outputs a detection signal. The reflector is set so that a scanning speed in a main scanning direction of the laser beam on a light-receiving surface of the synchronization sensor becomes greater than a value obtained by dividing a scanning distance of the laser beam in the main scanning direction on the light-receiving surface of the synchronization sensor by a response delay time of the synchronization sensor.

Abstract: An image forming apparatus includes a plurality of optical scanning devices, a mode receiver, a temperature condition judger and a temperature adjuster. In the case of forming an image using one optical scanning device, the temperature adjuster drives motors of unused optical scanning devices at a first rotation speed if a predetermined temperature condition is satisfied and drives the motors of the unused optical scanning devices at a second rotation speed slower than the first rotation speed if image formation is finished during the drive at the first rotation speed.

Abstract: An image forming apparatus includes a plurality of optical scanning devices, a job receiver, a job executor, an image discriminator, a temperature condition judger and a temperature adjuster. When a formation-target image is a single-color image and an image to be formed next is a multi-color image, the temperature adjuster drives a motor of one optical scanning device at a second rotating speed slower than a rotating speed during an image forming operation and drives motors of unused optical scanning devices at a third rotating speed faster than the second rotating speed if a temperature condition is satisfied upon the completion of an image forming operation of the single-color image.

Abstract: An optical scanning apparatus, including: a light source; an incident optical system; and an imaging optical system, in which: the imaging optical system includes at least one plastic lens; in a sub-scanning section, principal rays of the beams intersect each other on an optical axis of the imaging optical system; the principal rays intersect each other at different positions between a case of entering a central region of the at least one plastic lens and a case of entering an end region of the at least one plastic lens; and the principal rays entering one of the central region and the end region of the at least one plastic lens intersect each other, and the principal rays entering another of the central region and the end region of the at least one plastic lens intersect each other.

Abstract: A light scanning unit includes a light source to emit a light beam; a polygonal mirror to deflect the light beam in a main scanning direction; and an imaging optical system to image the light beam onto a scanning surface. The polygonal mirror includes a plurality of reflection surfaces that are formed in an outer portion of the polygonal mirror and rotate around a rotational axis and an internal mirror surface that defines a hole. A ratio of an internal diameter d to an outer diameter D satisfies 0.1?d/D?0.3. The polygonal mirror is adhered to a motor unit that supports and rotates the polygonal mirror, using an adhesive. The internal mirror surface of the polygonal mirror defining the hole is point-bonded to the motor unit using the adhesive, and the point-bonding is conducted in a direction toward a corner of the reflection surfaces.

Abstract: A visible laser beam scanned by a galvano-scanner system is aligned at each of positioning points on the top surface of a master work by manual operation to record sensor position signals of position sensors on galvano-scanners. The sensor position signals on each positioning point are recorded to create a drive pattern in accordance with recorded sensor position signals. The drive pattern no longer has optics system error sources including focus error and attachment error as well as errors caused by scale, offset and the like, also eliminating the need for entering a distance as far as the top surface of the work. Therefore, the drive pattern with error components removed can be created with ease.