Patent Description:
Prior technology with laser/scanner perforation on aerostructures materials utilizes a combination of n lasers in conjunction with a galvo-based x-y scanner. Although control of beam direction can be realized with the x-y scanners, it comes at speeds that are much slower than are desired for use in connection with aerostructure production. In a standard two galvanometer mirror system, the mirrors are commanded to some position and the laser is made to emit light. Although flexible in terms of pointing control in two planes, and adequate for many applications, this configuration yields a relatively slow process for creating perforations for aerostructures.

<CIT>, according to its abstract, describes a laser drilling method and drilling apparatus, wherein a polygon mirror, a mask having a row of holes for defining a processing pattern, a galvano-mirror, and a processing lens are arranged in that order between a laser oscillator and a printed circuit board as a workpiece. The laser beam from the laser oscillator is projected onto the printer circuit board travelling through these components. The polygon mirror sweeps the laser beam so that the laser beam scans the holes of the mask for the mirror on each face, and a plurality of holes are thereby formed into the printed circuit board.

According to the present invention, a perforation system is defined in claim <NUM>, and includes a movable base, a laser, a first polygon mirror, and a controller. The laser is mounted in a fixed position on the movable base, while the first polygon mirror is rotatably mounted on the movable base. The controller is configured to dispose the movable base in each of a plurality of fixed positions, and furthermore to operate the laser and rotate the first polygon mirror to define a plurality of perforations throughout a predetermined area of a substrate for each of the plurality of fixed positions for the movable base.

Various embodiments of perforation systems are disclosed herein that may be configured/operated to form one or more perforations on a substrate of any appropriate configuration (e.g., substrate in the form of a plate or plate-like structure; a substrate in the form of a curved structure), on a substrate formed from any appropriate material or combination of materials (e.g., a composite, CFRP (carbon fiber reinforced polymer), CMC (ceramic matrix composite), GFRP (glass fiber reinforced polymer), metal, alloys, ceramics), and including all combinations thereof. These perforations may be of any desired perimeter configuration (e.g., a shape or profile of the perforation in a plan view) and/or size. <FIG> illustrates a substrate 10a having such a perforation 12a in the form of a through-hole (i.e., the perforation 12a extends completely through the substrate 10a), where this perforation 12a has a perimeter 14a that defines the perimeter configuration of the perforation 12a. <FIG> illustrates a substrate 10b having such a perforation 12b in the form of a recess or blind hole (i.e., the perforation 12b fails to extend completely through the substrate 10b, so the perforation 12b instead defines a concave recess on a surface of the substrate 10b), where this perforation 12b has a perimeter 14b that defines the perimeter configuration of the perforation 12b. <FIG> is a plan view of a perforation <NUM> having a circular perimeter <NUM>, and that may be utilized for the perforation 12a of <FIG> or the perforation 12b of <FIG>.

The embodiments of perforation systems disclosed herein may be configured/operated to form any appropriate number of perforations on a substrate, in any appropriate layout/arrangement, and with any appropriate spacing between adjacent pairs of perforations. Representative layouts/arrangements of perforations that may be formed by the embodiments of perforation systems disclosed herein are illustrated in <FIG>. The substrate 10c of <FIG> includes a plurality of circular perforations 12c that are disposed in a plurality of rows that are spaced from one another. The substrate 10d of <FIG> includes a plurality of square perforations 12d that are disposed in a plurality of rows that are spaced from one another. Any appropriate spacing between adjacent pairs of perforations in a given row may be utilized, including a common spacing between adjacent pairs of perforations throughout a given row. The same or a different spacing between adjacent pairs of perforations may be utilized in one or more rows.

Perforations formed by any of the embodiments of perforation systems disclosed herein may provide any appropriate function or combination of functions. Representative functions for these perforations on a surface of a substrate include without limitation addressing acoustics (dampening) (the addition of perforations to a surface of a substrate may be characterized as an acoustic treatment of the substrate), addressing aerodynamic drag (e.g., improving laminar flow), surface conditioning (e.g., to enhance bonding, to enhance hydrophobic properties), cutting, trimming, welding, and the like. One application for the embodiments of perforation systems disclosed herein is to create perforations on a substrate that is used as an aerostructure (e.g., a component of an airframe for an aircraft; an exterior surface of an aerostructure).

A perforation system is illustrated in <FIG>. is identified by reference numeral <NUM>, and is configured/operated to form a plurality of perforations of a predetermined perimeter configuration and size on a surface <NUM> of a substrate <NUM> in accordance with the foregoing. The perforation system <NUM> may be characterized as including an optical system <NUM>. Components of this optical system <NUM> include a laser <NUM>, a first polygon mirror <NUM>, and a mirror <NUM>.

The laser <NUM> may be of any appropriate type/configuration, of any appropriate pulse repetition rate, pulse width, power, and wavelength (e.g., YAG; <NUM>, <NUM> ns, <NUM> W, <NUM>), and generates a laser beam <NUM> that proceeds along an optical path to the substrate <NUM>. The laser beam <NUM> may be output by the laser <NUM> in the form of a pulse that is issued at any appropriate frequency (e.g., a fixed frequency). One or more embodiments has the position of the laser <NUM> being fixed relative to the first polygon mirror <NUM> - more specifically the position of the laser <NUM> may be fixed relative to the position of a rotational axis <NUM> of the first polygon mirror <NUM>. The impacting of the laser beam <NUM> on the surface <NUM> of the substrate <NUM> removes corresponding material from the substrate <NUM> (e.g., via ablation, vaporization, or the like of the material defining the substrate <NUM>).

The first polygon mirror <NUM> may be disposed between the laser <NUM> and the mirror <NUM> along the optical path of the laser beam <NUM> proceeding from the laser <NUM> to the substrate <NUM>, although both the first polygon mirror <NUM> and the <NUM> mirror may be disposed at any appropriate position along the noted optical path. Operation of the perforation system <NUM> may include continuously rotating the first polygon mirror <NUM> at a constant rotational velocity about its rotational axis <NUM> (e.g., an appropriate rotational drive may be interconnected with the first polygon mirror <NUM>). A plurality of faces <NUM> are disposed on a perimeter of the first polygon mirror <NUM>. Any appropriate number of faces <NUM> may be disposed on the perimeter of the first polygon mirror <NUM> (six in the illustrated embodiment). Each of these faces <NUM> are flat or planar surfaces in one or more embodiments. Moreover, these faces <NUM> are each disposed at least substantially parallel to the rotational axis <NUM> of the first polygon mirror <NUM> for the case of the perforation system <NUM>. As such, a vector <NUM> that is normal to its corresponding face <NUM> is parallel to or colinear with the same vector <NUM> of each other face <NUM> of the first polygon mirror <NUM> when disposed in the same rotational or angular position relative to the rotational axis <NUM>.

A common included angle θ exists between each adjacent pair of faces <NUM> of the first polygon mirror <NUM> (e.g., <FIG>). Although adjacent faces <NUM> may intersect along a line, any appropriate transition may be used between each adjacent pair of faces <NUM> (e.g., a chamfer; a rounded or convex transition surface). Where the laser beam <NUM> impacts a given face <NUM> between its corresponding pair of ends <NUM> (the spacing between a pair of adjacent ends <NUM> may be referred to as defining a length dimension of the corresponding face <NUM>) will determine where the laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> in the x dimension noted in <FIG>.

The mirror <NUM> may be disposed between the first polygon mirror <NUM> and the substrate <NUM> along the optical path of the laser beam <NUM> proceeding from the laser <NUM> to the substrate <NUM>, but again the mirror <NUM> may be disposed at any appropriate position along the noted optical path. The position of the mirror <NUM> is controlled by a drive <NUM> (e.g., a servomotor or a galvanometer) that rotates the mirror <NUM> about a rotational axis <NUM>. The mirror <NUM> may be referred to as a galvanometer mirror or scanner <NUM>. In any case, the position of the mirror <NUM> controls where the laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> in the y dimension noted in <FIG>. One or more other optical components may be located along the optical path between the mirror <NUM> and the substrate <NUM>, for instance such that the laser beam <NUM> impacts the substrate <NUM> normal to its surface <NUM>.

Operation of the perforation system <NUM> will be addressed with regard to <FIG> and <FIG>. <FIG> shows a plurality of row sets <NUM> that extend in the x dimension and that are spaced from one another in the y dimension (e.g., the plurality of row sets <NUM> may be disposed in parallel relation to one another). Each row set <NUM> may be characterized as including a plurality of rows <NUM> that also extend in the x dimension and that are spaced from one another in the y dimension (e.g., the plurality of rows <NUM> may be disposed in parallel relation to one another). Generally and as shown in <FIG>, the laser <NUM> may be activated such that its laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> at each of the locations shown in <FIG> to define a plurality of perforations <NUM> in each row set <NUM>, where each of these perforations <NUM> will ultimately have a predetermined perimeter configuration, and where the perforations <NUM> in each row set <NUM> are spaced from one another in any appropriate fashion (e.g., an equally spaced relation within the given row set <NUM>).

Generally, the mirror <NUM> may be moved to a fixed position where the laser beam <NUM> will impact the surface <NUM> of the substrate <NUM> along one of the rows <NUM> (or between an adjacent pair of rows <NUM>) of a particular row set <NUM>. The laser <NUM> will be pulsed such that it impacts the surface <NUM> of the substrate <NUM> at predetermined locations along the given row <NUM> (or in the x dimension) to define a corresponding portion of each of the perforations <NUM>, and that is achieved by the laser beam <NUM> being reflected from a face <NUM> of the first polygon mirror <NUM> as it is being rotated at a constant rotational speed about its rotational axis <NUM>. Again, the location of where the laser beam <NUM> impacts a face <NUM> of the first polygon mirror <NUM> (e.g., where the laser beam <NUM> impacts a face <NUM> along its length dimension), determines where the laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> in the x dimension. The mirror <NUM> may be incremented between a number of different fixed positions such that the laser beam <NUM> will impact the surface <NUM> of the substrate <NUM> along each of the rows <NUM> (or between each of the rows <NUM>) of a particular row set <NUM> to define each of the desired perforations <NUM> in this row set <NUM> and where each perforation <NUM> will ultimately have a predetermined perimeter configuration.

One way in which the perforations <NUM> shown in <FIG> may be produced will be summarized. The mirror <NUM> may be positioned such that the laser beam <NUM> will impact the surface <NUM> of the substrate <NUM> on the second row <NUM> (the second down from the top in the view of <FIG>) of the upper row set <NUM> in the view of <FIG>. With the mirror <NUM> remaining in this fixed position, the laser <NUM> may be pulsed and reflected by one or more faces <NUM> of the rotating first polygon mirror <NUM> to impact the surface <NUM> of the substrate <NUM> at the locations shown in <FIG> (these locations being spaced from one another in the x dimension but occupying the same position in the y dimension). This may need to be repeated a plurality of times in order for each of the perforations <NUM> to extend to the desired depth within the substrate <NUM> (including for a given perforation <NUM> to extend through the entire thickness of the substrate <NUM>). Thereafter, the mirror <NUM> may be incremented/moved to a position where the laser beam <NUM> will impact the surface <NUM> of the substrate <NUM> on the next row <NUM> proceeding in the y dimension (e.g., to another location in the y dimension). With the mirror <NUM> remaining in this new fixed position, again the laser <NUM> may be pulsed and reflected by one or more faces <NUM> of the rotating first polygon mirror <NUM> to impact the surface <NUM> of the substrate <NUM> at the locations shown in <FIG> (these locations being spaced from one another in the x dimension but occupying the same position in the y dimension). This may be repeated until each of the perforations <NUM> in the row set <NUM> have been defined, and also may be repeated for each row set <NUM> in which one or more perforations <NUM> are to be defined.

Based upon the foregoing, it should be appreciated that the mirror <NUM> is moved in increments dy to form the desired perforations <NUM> in a particular row set <NUM>, and is moved in a larger increment Dy to move from one row set <NUM> to an adjacent row set <NUM>. Although the perforation system <NUM> may be operated to scan or sequence in a top-to-down fashion in the view shown in <FIG>, and where the entire depth of each perforation in a given row <NUM> may be defined prior to proceeding to the next row <NUM> in the same row set <NUM> (or more generally to another location in the y dimension), other operational configurations may be utilized. For instance, perforations <NUM> may be partially defined in each row <NUM> of a given row set <NUM>, although this would require more incremental movements of the mirror <NUM> (e.g., ½ of the desired perforation depth for each perforation <NUM> in a given row set <NUM> may be defined by a first set of incremental movements of the mirror <NUM>, and this may then be repeated to define the remainder of the desired perforation depth for each perforation in this same row set <NUM>), and this may apply to each row set <NUM>.

Another perforation system is illustrated in <FIG>, is identified by reference numeral <NUM>, and is configured/operated to form a plurality of perforations of a predetermined perimeter configuration and size on a surface <NUM> of a substrate <NUM> in accordance with the foregoing. Corresponding components between the perforation system <NUM> of <FIG> and the perforation system <NUM> of <FIG> are identified by the same reference numeral and the corresponding discussion above remains applicable to the perforation system <NUM> unless otherwise noted.

The perforation system <NUM> includes an optical system <NUM>. Components of this optical system <NUM> include the laser <NUM>, a first polygon mirror 130a, and the mirror <NUM>. The first polygon mirror 130a is disposed between the laser <NUM> and the mirror <NUM> along the optical path of the laser beam <NUM> proceeding from the laser <NUM> to the substrate <NUM>, although both the first polygon mirror 130a and the mirror <NUM> may be disposed at any appropriate position along the noted optical path. Operation of the perforation system <NUM> may include continuously rotating the first polygon mirror 130a at a constant rotational velocity about its rotational axis <NUM>. A plurality of faces 134a are disposed on a perimeter of the first polygon mirror 130a. Any appropriate number of faces 134a may be disposed on the perimeter of the first polygon mirror 130a (six in the illustrated embodiment). Each of these faces 134a are flat or planar surfaces in one or more embodiments. Unlike the case of the perforation system <NUM> discussed above, these faces 134a are each disposed in a different orientation relative to the rotational axis <NUM> of the first polygon mirror 130a and as shown in <FIG>.

<FIG> shows the orientation of the rotational axis <NUM> of the first polygon mirror 130a, along with a reference plane <NUM> that corresponds with one of the faces 134a. As such, a vector 140a that is orthogonal to this face 134a is disposed in an orientation other than perpendicular to the rotational axis <NUM> of the first polygon mirror 130a. Stated another way, there is an included angle Φ between the rotational axis <NUM> and the reference plane <NUM>, and this included angle Φ may be any appropriate value that is greater than <NUM>°. Based upon the different orientation of each face 134a of the first polygon mirror 130a, the vector 140a will be in a different orientation for each of the faces 134a of the first polygon mirror 130a when in the same rotational or angular position relative to the rotational axis <NUM> (see <FIG>).

Although adjacent faces 134a of the first polygon mirror 130a may intersect along a line, any appropriate transition may be used between each adjacent pair of faces 134a (e.g., a chamfer; a rounded or convex transition surface). Again, where the laser beam <NUM> impacts a given face 134a between its corresponding pair of ends <NUM> (or along the length dimension of such a face 134a) will determine where the laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> in the x dimension noted in <FIG>.

The position of the mirror <NUM> again is controlled by the drive <NUM>. Generally, the position of the mirror <NUM> at least partially controls where the laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> in the y dimension noted in <FIG>. However, the different orientations of the faces 134a of the first polygon mirror <NUM> also controls where the laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> in the y dimension noted in <FIG>. One or more other optical components may be located along the optical path between the mirror <NUM> and the substrate <NUM>, for instance such that the laser beam <NUM> impacts the substrate <NUM> normal to its surface <NUM>.

Operation of the perforation system <NUM> will be addressed with regard to <FIG> and <FIG>. <FIG> shows a plurality of row sets <NUM> that extend in the x dimension and that are spaced from one another in the y dimension (e.g., the plurality of row sets <NUM> may be disposed in parallel relation to one another). Each row set <NUM> may be characterized as including a plurality of rows <NUM> that also extend in the x dimension and that are spaced from one another in the y dimension (e.g., the plurality of rows <NUM> may be disposed in parallel relation to one another). Generally and as shown in <FIG>, the laser <NUM> may be activated such that its laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> at each of the locations shown in <FIG> to define a plurality of perforations <NUM> in each row set <NUM>, where each of these perforations <NUM> will ultimately have a predetermined perimeter configuration and size, and where the perforations <NUM> in each row set <NUM> are spaced from one another in any appropriate fashion (e.g., an equally spaced relation within the given row set <NUM>).

Generally, the mirror <NUM> may be moved to a fixed position where the laser beam <NUM> will impact the surface <NUM> of the substrate <NUM> within a particular row set <NUM> at each of a plurality of locations that are spaced in the y dimension (depending upon from which face 134a the laser beam <NUM> was reflected). That is, each face 134a of the first polygon mirror 130a is associated with a different location in the y dimension shown in <FIG>. The laser <NUM> will be pulsed such that it impacts the surface <NUM> of the substrate <NUM> at predetermined locations (either along a given row <NUM> or between an adjacent pair of rows <NUM> in the corresponding row set <NUM> and as shown in <FIG>) to define a corresponding portion of each of the perforations <NUM> in the row set <NUM>, and that is achieved by the laser beam <NUM> being reflected from a corresponding face 134a of the first polygon mirror 130a as it is being rotated at a constant rotational speed about its rotational axis <NUM>. Again, the location of where the laser beam <NUM> impacts a face 134a of the first polygon mirror 130a (e.g., where the laser beam <NUM> impacts a face 134a along its length dimension), determines where the laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> in the x dimension (and in the corresponding row <NUM> or between the corresponding pair of adjacent rows <NUM>). Unlike the perforation system <NUM> of <FIG>, the mirror <NUM> of the perforation system <NUM> of <FIG> need not be incremented to different fixed positions in order for the laser beam <NUM> to scan each of the rows <NUM> of a particular row set <NUM> to define each of the desired perforations <NUM> in this row set <NUM> (and again where each perforation <NUM> has a predetermined perimeter configuration and size). Stated another way, the mirror <NUM> need not be moved to define the entirety of each perforation <NUM> in the same row set <NUM> on the substrate <NUM> - the different impact locations of the laser beam <NUM> in the y dimension are provided by having the first polygon mirror 130a include a plurality of faces 134a that are each disposed in a different orientation relative to the rotational axis <NUM>.

One way in which the perforations <NUM> shown in <FIG> may be produced will be summarized. The mirror <NUM> may be positioned such that the laser beam <NUM> will impact the surface <NUM> of the substrate <NUM> within the upper row set <NUM> in the view of <FIG> (location <NUM>). With the mirror <NUM> remaining in this fixed position, the laser <NUM> may be pulsed and reflected by the various faces 134a of the rotating first polygon mirror <NUM> to impact the surface <NUM> of the substrate <NUM> at the locations shown in <FIG> (again, each face 134a of the first polygon mirror 130a will be associated with a different location within the y dimension of a given row set <NUM>). This may need to be repeated a plurality of times in order for each of the perforations <NUM> (within a common row set <NUM>) to extend to the desired depth within the substrate <NUM> (including for a given perforation <NUM> to extend through the entire thickness of the substrate <NUM>).

After all the perforations <NUM> in the row set <NUM> have been defined in accordance with the foregoing, the mirror <NUM> may be moved to a different fixed position where the laser beam <NUM> will impact the surface <NUM> of the substrate <NUM> within a different row set <NUM> at each of a plurality of locations that are spaced in the y dimension (depending upon from which face 134a the laser beam <NUM> was reflected), for instance locations <NUM>, <NUM>, <NUM>, and <NUM> shown in <FIG>. This movement of the mirror <NUM> is shown as Dy in <FIG>. Although the perforation system <NUM> may be operated to sequence in a top-to-down fashion in the view shown in <FIG>, and where the entire depth of each perforation <NUM> in a given row set <NUM> may be defined prior to proceeding to the next row set <NUM>, other operational configurations may be utilized. For instance, perforations <NUM> may be partially defined in each of the row sets <NUM>, although this would require more incremental movements of the mirror <NUM> (e.g., ½ of the desired perforation depth for each perforation <NUM> in each row set <NUM> may be defined by a first set of incremental movements of the mirror <NUM>, and this may then be repeated to define the remainder of the desired perforation depth for each perforation <NUM> in each row set <NUM> by repeating the noted incremental movements of the mirror <NUM>). A further perforation system is illustrated in <FIG>, is identified by reference numeral <NUM>, and is configured/operated to form a plurality of perforations of a predetermined perimeter configuration and size on a surface <NUM> of a substrate <NUM> in accordance with the foregoing. Corresponding components between the perforation system <NUM> of <FIG> and the perforation system <NUM> of <FIG> are identified by the same reference numerals and the corresponding discussion above remains applicable to the perforation system <NUM> unless otherwise noted.

The perforation system <NUM> includes an optical system <NUM>. Components of this optical system <NUM> include the laser <NUM>, the first polygon mirror <NUM>, a second polygon mirror <NUM>, and the mirror <NUM>, and each of which may be disposed at any appropriate position along the optical path proceeding from the laser <NUM> to the substrate <NUM>. The first polygon mirror <NUM> may be disposed between the laser <NUM> and the second polygon mirror <NUM> along the optical path of the laser beam <NUM> proceeding from the laser <NUM> to the substrate <NUM>, and is rotated at a constant rotational velocity about its rotational axis <NUM>. As in the case of the perforation system <NUM> of <FIG>, the first polygon mirror <NUM> of the perforation system <NUM> of <FIG> controls where the laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> in the x dimension. More specifically, where the laser beam <NUM> impacts a given face <NUM> along its length dimension will determine where the laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> in the x dimension noted in <FIG>.

The second polygon mirror <NUM> may be disposed between the first polygon mirror <NUM> and the mirror <NUM> along the optical path of the laser beam <NUM> proceeding from the laser beam <NUM> to the substrate <NUM>. Operation of the perforation system <NUM> may include continuously rotating the second polygon mirror <NUM> at a constant rotational velocity about its rotational axis <NUM> (e.g., an appropriate rotational drive may be interconnected with the second polygon mirror <NUM>). A plurality of faces <NUM> are disposed on a perimeter of the second polygon mirror <NUM>. Any appropriate number of faces <NUM> may be disposed on the perimeter of the second polygon mirror <NUM> (six in the illustrated embodiment). Each of these faces <NUM> are flat or planar surfaces in one or more embodiments. Moreover, these faces <NUM> are disposed parallel to the rotational axis <NUM> of the second polygon mirror <NUM> for the case of the perforation system <NUM> (e.g., in accord with the first polygon mirror <NUM> and as described above). As such, a vector that is normal to its corresponding face <NUM> is parallel to or colinear with the same vector of each other face <NUM> of the second polygon mirror <NUM> when disposed in the same rotational or angular position relative to the rotational axis <NUM>.

A common included angle exists between each adjacent pair of faces <NUM> of the second polygon mirror <NUM>, similar to the first polygon mirror <NUM> discussed above. Although adjacent faces <NUM> may intersect along a line, any appropriate transition may be used between each adjacent pair of faces <NUM> (e.g., a chamfer; a rounded or convex transition surface). Where the laser beam <NUM> impacts a given face <NUM> between its corresponding pair of ends <NUM> (and that may be referred to as defining a length dimension of such a face <NUM>) will at least in part determine where the laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> in the y dimension noted in <FIG>.

The orientation of the rotational axis <NUM> for the first polygon mirror <NUM> is different than the orientation of the rotational axis <NUM> for the second polygon mirror <NUM>. The rotational axis <NUM> of the first polygon mirror <NUM> is orientated to control where the laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> in the x dimension noted in <FIG>. In contrast, the rotational axis <NUM> of the second polygon mirror <NUM> is orientated to control where the laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> in the y dimension noted in <FIG>. For the case where the number of faces <NUM> used by first polygon mirror <NUM> is the same as the number of faces <NUM> used by the second polygon mirror <NUM>, the first polygon mirror <NUM> may be rotated at a different rate than the second polygon mirror <NUM>, including where the first polygon mirror <NUM> is rotated at a higher rotational speed than the second polygon mirror <NUM> (although both polygon mirrors <NUM>, <NUM> will typically each be rotated at a constant rotational speed). The first polygon mirror <NUM> and the second polygon mirror <NUM> could be rotated at a common rotational speed if the number of faces <NUM> for the first polygon mirror <NUM> differed from the number of faces <NUM> for the second polygon mirror <NUM>.

The mirror <NUM> may be disposed between the second polygon mirror <NUM> and the substrate <NUM> along the optical path of the laser beam <NUM> proceeding from the laser <NUM> to the substrate <NUM>. The position of the mirror <NUM> is again controlled by the drive <NUM> that rotates the mirror <NUM> about its rotational axis <NUM>. Generally, the position of the mirror <NUM> controls in part where the laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> in the y dimension noted on <FIG> (again, the rotating second polygon mirror <NUM> also controls in part where the laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> in the y dimension noted on <FIG>). One or more other optical components may be located along the optical path between the mirror <NUM> and the substrate <NUM>, for instance such that the laser beam <NUM> impacts the substrate <NUM> normal to its surface <NUM>.

Operation of the perforation system <NUM> of <FIG> is at least somewhat functionally similar to what is shown and described above in relation to <FIG> and the perforation system <NUM>. <FIG> shows a plurality of row sets <NUM> that each extend in the x dimension and that are spaced from one another in the y dimension (e.g., the plurality of row sets <NUM> may be disposed in parallel relation to one another). Each row set <NUM> includes a plurality of rows <NUM> (see <FIG>) that also extend in the x dimension and that are spaced from one another in the y dimension (e.g., the plurality of rows in a given row set <NUM> may be disposed in parallel relation to one another). Generally and as shown in <FIG>, the laser <NUM> may be activated such that its laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> at each of the locations shown in <FIG> to define a plurality of perforations <NUM> in a given row set <NUM>, where each of these perforations <NUM> will ultimately have a predetermined perimeter configuration and size, and where the perforations <NUM> in a given row set <NUM> are spaced from one another in any appropriate fashion (e.g., an equally spaced relation within the given row set <NUM>). Each of the row sets <NUM> are separately scanned by the laser <NUM> in the case of the perforation system <NUM> of <FIG>.

Generally, the mirror <NUM> in the case of the perforation system <NUM> of <FIG> may be moved to a fixed position where the laser beam <NUM> will impact the surface <NUM> of the substrate <NUM> within a particular row set <NUM> at each of a plurality of locations that are spaced in the y dimension (via the rotating second polygon mirror <NUM>). Within this row set <NUM>, where the laser beam <NUM> will impact the surface <NUM> of the substrate <NUM> in the y dimension will depend upon where the laser beam <NUM> impacts a face <NUM> of the second polygon mirror <NUM> along its length dimension. The laser <NUM> will further be pulsed such that it impacts the surface <NUM> of the substrate <NUM> at predetermined locations in the x dimension (either along a given row or between an adjacent pair of rows of a corresponding row set <NUM>) to define a corresponding portion of each of the perforations <NUM> in the row set <NUM>, and that is achieved by the laser beam <NUM> being reflected from a corresponding face <NUM> of the first polygon mirror <NUM> as it is being rotated at a constant rotational speed about its rotational axis <NUM>. Again, the location of where the laser beam <NUM> impacts a face <NUM> of the first polygon mirror <NUM> (e.g., where the laser beam <NUM> impacts a face <NUM> along its length dimension), determines where the laser beam <NUM> impacts the surface <NUM> of the substrate <NUM> in the x dimension (and in the corresponding row or between the corresponding pair of adjacent rows of the current row set <NUM>). Unlike the perforation system <NUM> of <FIG>, the mirror <NUM> of the perforation system <NUM> of <FIG> need not be incremented to different fixed positions in order for the laser beam <NUM> to scan each of the rows of a particular row set <NUM> to define each of the desired perforations <NUM> in this row set <NUM> (and again where each perforation <NUM> will ultimately have a predetermined perimeter configuration and size). This capacity for different locations in the y dimension within a particular row set <NUM> is provided by the rotating second polygon mirror <NUM>.

One way in which the perforations <NUM> shown in <FIG> may be produced by the perforation system <NUM> of <FIG> will be summarized. The mirror <NUM> may be positioned such that the laser beam <NUM> will impact the surface <NUM> of the substrate <NUM> within the upper row set <NUM> in the view of <FIG> (i.e., location <NUM>). With the mirror <NUM> remaining in this fixed position, the laser <NUM> may be pulsed and its laser beam <NUM> reflected by one or more faces <NUM> of the rotating first polygon mirror <NUM> (to have the laser beam <NUM> impact the surface <NUM> of the substrate <NUM> at a particular location in the x dimension in the row set <NUM>) and the laser beam <NUM> will also be reflected by one or more faces <NUM> of the rotating second polygon mirror <NUM> (to have the laser beam <NUM> impact the surface <NUM> of the substrate <NUM> at a particular location in the y dimension in the row set <NUM>). This may need to be repeated a plurality of times in order for each of the perforations <NUM> (within a common row set <NUM> - <FIG>) to extend to the desired depth within the substrate <NUM> (including for a given perforation <NUM> to extend through the entire thickness of the substrate <NUM>).

After all the perforations <NUM> in the noted row set <NUM> have been defined in accordance with the foregoing via operation of the perforation system <NUM> of <FIG>, the mirror <NUM> may be moved to a different fixed position (one of locations <NUM>, <NUM>, <NUM>, and <NUM> shown in <FIG>) for repetition in accordance with the foregoing. This movement of the mirror <NUM> is shown as Dy in <FIG>. Although the perforation system <NUM> of <FIG> may be operated to scan or sequence in a top-to-down fashion in the view shown in <FIG>, and where the entire depth of each perforation <NUM> in a given row set <NUM> is defined prior to proceeding to the next row set <NUM>, other operational configurations may be utilized. For instance, perforations <NUM> may be partially defined in each of the row sets <NUM>, although this would require more incremental movements of the mirror <NUM> (e.g., ½ of the desired perforation depth for each perforation <NUM> in each row set <NUM> may be defined by a first set of incremental movements of the mirror <NUM>, and this may then be repeated to define the remainder of the desired perforation depth for each perforation in each row set <NUM> by repeating the noted incremental movements of the mirror <NUM>). It should also be appreciated that the laser <NUM> may separately scan the various row sets <NUM> in any order (i.e., it is not required to sequence through the row sets <NUM> in order).

Another further perforation system is illustrated in <FIG>, is identified by reference numeral 300a, and is configured/operated to form a plurality of perforations of a predetermined perimeter configuration and size on a surface <NUM> of a substrate <NUM> in accordance with the foregoing. The perforation system 300a uses the same components as the perforation system <NUM> of <FIG>. However, the perforation system 300a of <FIG> is operated differently than the perforation system <NUM> of <FIG> to form a plurality of perforations of a predetermined perimeter configuration and size on a surface <NUM> of a substrate <NUM> in accordance with the foregoing. In the case of the perforation system 300a, the second polygon mirror <NUM> may be rotating at a higher rotational speed than in the case of the perforation system <NUM> of <FIG>. One or more other optical components may be located along the optical path between the mirror <NUM> and the substrate <NUM>, for instance such that the laser beam <NUM> impacts the substrate <NUM> normal to its surface <NUM>.

Operation of the perforation system 300a of <FIG> again will be described in relation to <FIG>. Generally and for a single fixed position of the mirror <NUM>, the laser beam <NUM> from the laser <NUM> will be scanned to impact various locations in multiple row sets <NUM> (e.g., <FIG>). For instance and again for a single fixed position of the mirror <NUM>, the laser beam <NUM> from the laser <NUM> may be scanned to impact various locations in each of the row sets <NUM> shown in <FIG> (e.g., scanning from top to bottom in the view shown in <FIG> for a single, fixed position of the mirror <NUM>). This scan may need to be repeated a plurality of times in order for the corresponding portions of the perforations <NUM> (again, within each of multiple row sets <NUM>) to extend to the desired depth within the substrate <NUM> (including for a given corresponding portion of each perforation <NUM> to extend through the entire thickness of the substrate <NUM>). The location from which the laser beam <NUM> is reflected by a face <NUM> of the first polygon mirror <NUM> will determine the location in the x dimension where the laser beam <NUM> will impact the surface <NUM> of the substrate <NUM>, whereas the location from which the laser beam <NUM> is reflected by a face <NUM> of the second polygon mirror <NUM> will determine the location in the y dimension where the laser beam <NUM> will impact the surface <NUM> of the substrate <NUM>, all for a given fixed position of the mirror <NUM>.

The foregoing is repeated for each of a plurality of different positions of the mirror <NUM>, where each different position of the mirror will change the y dimension of the area of the substrate <NUM> that is scanned in accordance with the foregoing (see representative different positions a, b, and c in <FIG>). After the above-noted scanning has been repeated for each of certain number of different positions of the mirror <NUM>, this will ultimately define a plurality of perforations <NUM> in the substrate <NUM>, and where each such perforation <NUM> has a predetermined perimeter configuration and size.

Again, another further perforation system is illustrated in <FIG>, is identified by reference numeral 300b, and is configured/operated to form a plurality of perforations (e.g., perforations <NUM> - <FIG>) of a predetermined perimeter configuration and size on a surface of a substrate (e.g., substrate <NUM> - <FIG>) in accordance with the foregoing. The perforation system 300b includes the first polygon mirror <NUM> and the second polygon mirror <NUM> in accordance with the perforation systems <NUM>, 300a. The perforation system 300b further includes a first positioning mirror 150a (e.g., in accordance with the mirror <NUM> discussed above in relation to the perforation systems <NUM>, 300a), and a second positioning mirror 150b. The position of the second positioning mirror 150b is controlled by a drive <NUM> that rotates the second positioning mirror 150b about rotational axis 152b. The rotational axis 152a of the first positioning mirror 150a, and the rotational axis 152b of the second positioning mirror 150b are disposed in different orientations. The first polygon mirror <NUM>, the second polygon mirror <NUM>, the first positioning mirror 150a, and the second positioning mirror 150b each may be disposed at any appropriate position along the optical path proceeding from the laser <NUM> to the substrate <NUM>.

Generally, the second positioning mirror 150b may be moved/adjusted to accommodate formation of one or more perforations in different quadrants that occupy different positions in a first dimension (e.g., an x dimension). The first positioning mirror 150a may be moved/adjusted to accommodate formation of one or more perforations in different quadrants that occupy different positions in a second dimension (e.g., a y dimension) that is orthogonal to the first dimension. <FIG> illustrates four different quadrants 500a, 500b, 500c, and 500d. The second positioning mirror 150b provides for an adjustment in the x dimension (Dx in <FIG>), for instance to move from quadrant 500a to quadrant 500b, or to move from quadrant 500c to quadrant 500d. The first positioning mirror 150a provides for an adjustment in the y dimension (Dy in <FIG>), for instance to move from quadrant 500a to quadrant 500c, or to move from quadrant 500b to quadrant 500d.

The first polygon mirror <NUM>, the second polygon mirror <NUM>, and the first positioning mirror 150a furthermore may be operated to form one or more perforations <NUM> in each of these quadrants 500a, 500b, 500c, and 500d in accordance with the perforation system <NUM> or the perforation system 300b. The quadrant 500a and quadrant 500b occupy different positions in the noted first dimension, while the quadrant 500c and quadrant 500d occupy different positions in the noted first dimension. The quadrant 500a and the quadrant 500c occupy different positions in the noted second dimension, while the quadrant 500b and quadrant 500d occupy different positions in the noted second dimension.

The perforation systems <NUM>, <NUM>, <NUM>, 300a discussed above may be used to define a plurality of perforations over an area of a substrate of any appropriate size. One way in which this may be done is in accordance with the perforation system <NUM> that is schematically presented in <FIG>. The perforation system <NUM> includes an optical system <NUM>, a base <NUM>, and a controller <NUM>. The optical system <NUM> is in accordance with any of the perforation systems <NUM>, <NUM>, <NUM>, 300a discussed above. The controller <NUM> is operatively interconnected with both the base <NUM> and the optical system <NUM>, and may be of any appropriate configuration/architecture. For instance, the controller <NUM> is operatively interconnected with the laser <NUM>, the rotational drive source for the polygon mirrors <NUM>/130a, <NUM>, and the drive <NUM> for the mirror <NUM>. The base <NUM> may be moved in each of an x dimension <NUM> and a y dimension <NUM> such that after the optical system <NUM> has formed perforations on one section of a substrate, the base <NUM> may be moved such that the optical system <NUM> may thereafter form perforations on a completely different section of the same substrate. This may be done any appropriate number of times.

The above-discussed perforation system <NUM>, <NUM>, <NUM>, and 300a are believed to significantly reduce the amount of time to form a plurality of perforations compared to a standard two galvanometer mirror system. The advantage becomes more and more relevant as the size of the surface on which perforations are formed increases and when forming at least a certain number of perforations.

Claim 1:
A perforation system (<NUM>), comprising:
a movable base (<NUM>);
a laser (<NUM>) mounted in a fixed position on said movable base (<NUM>);
a first polygon mirror (<NUM>) rotatably mounted on said movable base (<NUM>); and
a controller (<NUM>) configured:
to dispose said movable base (<NUM>) in a plurality of fixed positions; and
to operate said laser (<NUM>) and to rotate said first polygon mirror (<NUM>) at a fixed rotational speed to define a plurality of perforations (<NUM>) throughout a predetermined area of a substrate (<NUM>) for each of said plurality of fixed positions of said movable base (<NUM>).