JP2016526725A - Ray tracing method and apparatus - Google Patents

Abstract

A ray tracing method and an apparatus for performing the method, which are used for an optical pointer, and as a basis for determining a moving direction, an optical sensor causes an interference pattern in which light generated in each reflected light path is strengthened and weakened. To get. By using a coherent light source, the interference effect can be enhanced. In this method, each guidance unit (301) of the sensing chip (32) receives reflected light (203) reflected from the surface, and each guidance unit (301) receives each guidance by the light received before and after the time interval. The energy received by the unit (301) is calculated, and the energy states of all or some of the induction units (301) before and after this time interval are calculated. In this method, the movement vector can be determined by the change in the energy state of the guidance / pixel of the guidance chip (32) before and after the time interval with respect to the statistical average value before and after the collection time. The present invention has a tracking function on any aspect of the plane, and can be applied to all high reflection or very low reflectivity planes.

Description

  The present invention relates to an optical pointing device, and more particularly, to a ray tracing method and device using a coherent light interference pattern and special binary acquisition imaging as a basis for determining a movement locus.

  FIG. 1 is a schematic diagram showing an internal circuit of a conventional optical mouse 10. The optical mouse 10 moves on the surface 11, and as a main part of the internal circuit of the mouse housing 12, in addition to some optical components, a circuit board 14 is provided in the circuit portion. A controller 18 for controlling and calculating sensing light, a light source 16 and a sensor 19 are provided.

  The housing 12 of the optical mouse 10 has one aperture 17 facing the outer surface 11, and the circuit board 14 is provided in the vicinity of the aperture 17. LED) light source 16 is provided. Shown as a dotted line in the drawing, when the optical mouse 10 is operated, the light source 16 continuously emits light, enters the surface 11 at a specific angle, and the sensor 19 obtains a signal of reflected light. Alternatively, an image distribution of reflected light intensity is obtained (sensor 19 may be a CMOS or CCD image sensor, for example), and controller 18 can analyze the direction of movement of optical mouse 10.

  The well-known technique for determining the trajectory of the optical mouse 10 strongly depends on the reflected light signal acquired by the surface 11, so that the function of the normal optical mouse 10 has different performance depending on the shape of the surface 11. Become.

  For example, if the surface 11 is a transparent material or a material that hardly reflects light, the optical mouse 10 cannot operate smoothly. The optical mouse 10 cannot be operated smoothly if the surface 11 has a non-planar structure in which the surface 11 undulates, such as a cloth having wrinkles.

  Conventionally, when the tracking device using the optical sensor tries to keep a tracking function to some extent even in different planes, a method of acquiring a light beam movement operation often uses additional external positioning sensing or complicated calculation. However, these positioning sensing or computations only apply to finite planar aspects due to sensitivity limitations, high energy consumption, and complex algorithms. These common schemes cannot adapt to all highly reflective or very low reflectivity planes and cannot even achieve the purpose of ray tracing.

  The present invention provides a ray tracing method and apparatus capable of solving the problems that conventional ray tracing devices cannot keep the tracking function in different planes and cannot be applied to all high reflection or extremely low reflectance planes. The purpose is to do.

The present invention is a ray tracing method,
The induction chip receives reflected light reflected from the surface, and includes a plurality of induction units in which the induction chip is arranged geometrically symmetrically.
Each guidance unit calculates the energy received by each guidance unit by the light received before and after the time interval,
Calculate the energy state of all or some induction units before and after the time interval, and the energy state of the induction unit in the induction chip before and after the time interval is a statistical average before and after the collection time. The movement vector is determined based on the change to.

  Specifically, the reflected light is a light beam having good spatial coherence.

  Specifically, the reflected light was obtained when a light beam emitted from the light source device was incident on the surface.

  Specifically, the light source device is a laser light device provided in an optical pointing device.

  Specifically, the induction chip is a sensor array of the plurality of induction units arranged in an array, and is provided in the optical pointing device to receive the reflected light.

  Specifically, the movement trajectory is determined by repeating the steps of the ray tracing method and calculating movement vectors at a plurality of time intervals.

Specifically, the time interval from the first time and the second time is the time interval, and the guidance unit calculates the energy state at the first time or the second time:
Calculating an average value of energy received by all or some of the induction units;
A difference between the energy received by each induction unit and the average value is calculated, and the difference includes a step for each induction unit to calculate an energy state at the first time or the second time.

Specifically, the steps for the guidance unit to calculate the change in the energy state before and after the time interval with respect to the statistical average value before and after the collection time are:
Determining the energy state of each induction unit at the first time;
Determining the energy state of each guidance unit at the second time;
The energy state from the first time to the second time of the guidance unit acquires a change with respect to a statistical average value before and after the collection time, and determines the movement vector.

The present invention is a ray tracing device using the ray tracing method of the above-mentioned claim,
A light source device for generating light incident on the surface;
A sensor array having the plurality of guidance units arranged in an array;
Couple the controller, the light source device and the sensor array, acquire the optical signals received by the plurality of guidance units, calculate the energy state, and before and after the collection time for the energy state before and after the time interval of the guidance unit Calculate the statistical mean change,
A ray tracing device, wherein the sensor array and the controller are integrated in a semiconductor circuit, and the light source device, the integrated sensor array, and the controller are sealed on a circuit board in the ray tracing device.

  Specifically, the ray tracing device is an optical pointing device using laser light as a light source.

  The present invention is a method and a ray tracing apparatus for performing ray tracing by reflection interference. As a basis for tracking identification, a pattern that interferes constructively and destructively between the light reflected by the surface and the original emitted light is used. It can be used, with a tracking function on any aspect of the plane, and can be applied to all high reflection or very low reflectivity planes.

FIG. 1 is a schematic diagram of an internal circuit of a conventional optical mouse. FIG. 2 is a schematic diagram of an incident plane and a reflected light path of reflected light according to the present invention. FIG. 3 is a schematic diagram of a sensor array sealed in an integrated circuit of the ray tracing device of the present invention. The flow shown in FIG. 4 is a step of the embodiment of the ray tracing method of the present invention. FIG. 5 is a schematic diagram of an embodiment of a sensor array used in the tracking device of the present invention. FIG. 6 is one of the schematic diagrams in which the guiding unit of the apparatus disclosed in the present invention performs the ray tracing method. FIG. 7 is another schematic diagram in which each guiding unit of the apparatus disclosed in the present invention performs a ray tracing method. The flow shown in FIG. 8 shows steps in which the tracking method determines a movement vector according to the direction of energy change.

  The technique using non-coherent light for determining the movement position usually requires a complicated data calculation program in order to determine the mouse movement locus, for example. Such a technique cannot be effective unless it is limited to several planes (for example, avoiding planes with very low light reflectivity). Therefore, the present invention discloses a ray tracing method and apparatus. One embodiment uses a coherent light as a light source, that is, a beam having good spatial coherence, thereby detecting a moving direction, and also combining a sensitivity compensation method, and a ray tracing algorithm. (Movement recognition algorithm) is used. Devices that use this technology are adaptable to all types of planes.

  The ray tracing apparatus proposed by the present invention employs a coherent light source integrated packaging technology (coherent light source package integration). A device employing such a technique, for example, an optical pointing device, does not need to mount an extra optical lens or a specific image sensor, for example, a complementary metal oxide semiconductor image sensor (CMOS image sensor, CIS).

  First, referring to a schematic diagram in which a specific light source device (not shown) shown in FIG. 2 generates incident light 201 and is incident on a plane and then reflected to form a plurality of reflected lights 203. As the light source, for example, coherent light of laser light is employed. The “coherent light” mentioned here is a light beam with good spatial coherence.

  The plurality of light paths shown in FIG. 2 include incident light 201 that is reflected after being incident on a plane having one surface structure 205 to form reflected light 203. Since the surface structure 205 is a micro irregular structure, the reflected light 203 is a light beam having different directions as shown in FIG.

  The light source device continuously generates incident light 201, enters the plane, and is reflected to form reflected light 203. Among them, the reflected light 203 is received by a sensor (not shown in FIG. 2), and a pattern of constructive interference and destructive interference (pattern) is generated in each optical path. Here, in particular, the use of the incident light 201 of the coherent light source can enhance this interference effect.

  When a device equipped with a related circuit for performing this tracking method moves with respect to the sensing plane (XY plane), the optical sensor receives the information of the reflected light 203 and changes the information in the information according to the time slot. Sampling is performed, and an average energy value of the reflected light 203 is obtained, and energy differences at different positions at different times of the reflected light 203 are calculated. In particular, the ray tracing device disclosed by the present invention preferably employs a sensor array, obtains the difference between the energy at different positions of the reflected light 203 and the average energy value, and determines the movement trajectory. it can. The average value of the reflected light 203 is calculated by using the energy average value acquired by all the guidance cells (sensor cells) or by using the energy average value acquired by some guidance units (for example, the row (X direction in FIG. 5). ) Average value or column (see Y direction in FIG. 5) average value may be used). It is also possible to use the energy average value in the peripheral or central portion as the reference average value.

  When coherent light is used as a light source according to one of the embodiments employing the above sensor array, the interference effect of reflected light can be enhanced. Coherent light is a light source having an extremely small phase delay in a wave envelope, and among them, laser light is a kind of coherent light, and is non-coherent such as sunlight or LED light. It is different from light.

  By applying coherent light to the tracking device disclosed in the present invention, the coherent light can improve the sensitivity of an optical sensor that senses interference of reflected light. The coherent light has a very small phase difference, so that the coherent light has a relatively small phase delay with respect to the spatial interference generated in the reflected light of the non-coherent light. Therefore, by adopting coherent light, the advantage of spatial interference of reflected light can be enhanced, and the difference in spatial interference in which light is reflected on one plane of the sensor array (with respect to the light beam) can be acquired.

  For the sensor array, reference can be made to the schematic diagram of the sensor array enclosed in the integrated circuit (IC) of the ray tracing apparatus of the present invention shown in FIG.

  FIG. 3 shows one sensor array 32 on a circuit board 30 provided in a device (for example, an optical mouse or a specific pointing device). The sensor array 32 has a plurality of induction units 301 arranged in an array. By this integrated packaging technology (integrated optical sensor array on IC), each induction unit 301 on the sensor array 32 is flat at a fixed position. It is possible to uniformly obtain the light beam reflected on the surface. In FIG. 3, the light source device 34 emits a light beam on one plane and hits the irradiation range 303, and the light beam is reflected by the plane and enters the sensor array 32. Among them, each induction unit 301 receives reflected light in a different direction, and by appropriate photoelectric signal conversion, a circuit related to the controller 36 integrated in the semiconductor circuit together with the sensor array 32 in the apparatus acquires the signal. After that, an average value obtained by adding the energy received by each induction unit 301 can be calculated. Then, a difference between each guidance unit 301 and the average value is calculated, and an energy difference (spatial interference difference) of the spatial interference reflected and formed on the plane is calculated. The controller 36 determines the moving direction based on the energy difference accumulated and calculated before and after every time slot.

  In the ray tracing device disclosed in the above embodiment, the spatial interference means that a light ray (particularly coherent light, but not limited to coherent light in the present invention) is incident on a surface having an irregular surface structure, Interference of light rays caused by reflection and generation of reflected light in different directions. After such a ray is reflected, it forms a pattern that interferes constructively or destructively, and then obtains spatial information of plane reflection due to relative movement (relative movement between the device and the plane) by the sensor array. , Create moving material on the XY plane.

  As shown in FIG. 3, particularly in one embodiment, the ray tracing device disclosed by the present invention is an optical pointing device using a laser beam as a light source, for example, an optical mouse. Among them, as main circuit components, a light source device 34 provided on a circuit board 30 for generating light incident on the surface, a sensor array 32 having a plurality of induction units 301 arranged in an array, And the controller 36 described above. The controller 36 couples the light source device 34 and the sensor array 32, obtains the optical signals received by the plurality of guides / pixels in the plurality of guide units 301, calculates the energy state, and the energy state of the time interval Calculates the change in the statistical average value before and after the collection time.

  The flow shown in FIG. 4 is a step of the embodiment of the ray tracing method of the present invention.

  In the flow of this embodiment, at the beginning of the step, as in step S401, the light source device provided in the ray tracing device emits a light beam and is incident on one surface, and then in step S403, the sensor in the device. Receives the reflected light.

  According to an embodiment, the light source is preferably, for example, coherent light. Its main purpose is to improve the sensitivity of detecting the moving direction by reflected light interference using the relatively small phase delay characteristic of coherent light. Among them, the light source device may be a laser beam device provided in the optical pointing device, and the sensor preferably uses a sensor array as shown in FIG.

  Thereafter, the ray tracing method disclosed by the present invention mainly calculates the energy states of all or part of the guidance unit before and after the time interval, and collects the energy states before and after the time interval of the guidance unit. The movement vector is determined by the change with respect to the statistical average value before and after the time. One implementation is described in detail as follows.

  After receiving the reflected light by the sensor, as in step S405, the control circuit in the apparatus calculates the energy received by each inductive unit before and after one time slot, and all in step S407. Or some guidance units (as in the example of FIG. 6, all guidance units / sensor pixels may not receive enough light for energy calculation) Calculate the average energy value obtained before and after (process at least two values at the same time). After calculating the energy of each induction unit and the energy average of all or part of each induction unit at different times before and after (for example, the row average value, column average value, ambient average value, and median average value as the reference average value), each induction The difference between the energy received by the unit and the average value can be calculated (in one embodiment, the difference here indicates the energy state of each inductive unit), as in step S409, within, before and after the time interval. Each of at least two differences is processed. There may be a difference between the two sets of numbers before and after the time interval, that is, the energy change before and after the time interval. After that, as in step S411, the movement vector of the apparatus that integrally uses this tracking technique is determined based on the energy change calculated by a plurality (at least two) of the guidance units in the guidance chip.

  By repeating the steps of the ray tracing method described above, motion vectors for a plurality of time intervals are calculated. From this, the movement trajectory within a predetermined time is determined. Among them, the method of determining the relative movement between the apparatus and the surface based on the sensed energy change in each induction unit may refer to the examples described in FIGS. You may refer to the flow shown in.

  FIG. 5 is a schematic diagram of an embodiment in which the sensor array used in the ray tracing device operates to calculate the energy distribution. According to the embodiment of the present invention, the tracking calculation method is requested to the circuit structure and sensor array shown in FIG.

  FIG. 5 shows the layout of the sensor array. A plurality of guidance units are distributed in the XY plane to form an N × M sensor array. A plurality of guide units 501, 502, 503, 504, and 505 arranged in an array are installed in the X and Y directions, respectively, but the actual number is not limited to this schematic diagram. Main components on the circuit board on which these induction units 501, 502, 503, 504, and 505 are laid are also a plurality of comparators 521, 522, 523, 524, and 525. Each comparator is connected to two corresponding induction units, and the input value is an average voltage signal Vavg of energy generated by each induction unit, and the induction unit compares the voltage signals obtained by sensing the light beam. Used to obtain a higher or lower voltage signal value. Finally, the tracking method acquires two adjacent sensor values, compares the results, and determines the moving direction.

  For example, the comparator 521 of FIG. 5 is coupled to the induction unit 501, and an energy signal obtained by sensing one input signal, that is, the induction unit 501, can be expressed as a voltage signal. Another input terminal is an average voltage signal Vavg, and the comparator 521 compares the two input signals and outputs one comparison result, for example, a high or low voltage signal represented by H or L shown in FIG. .

  According to the ray tracing method described in the present invention, the method of tracking is an energy distribution displayed in a pattern that interferes destructively with a beam (preferably coherent light) reflected by a plane. The movement vector is determined based on the change in the energy distribution at different times. In the implementation method, for example, a non-relative view points to do movement judgment is performed using a non-correlated viewpoint, that is, energy information of surrounding guidance units is drawn in and compared with the average guidance energy to determine the movement direction. To do. Incidentally, unlike the method of determining a movement vector using video image information (pixel) information in general, the present invention adopts time and energy change calculation (results of comparison of binary readings and statistical average values). , H and L) to determine the movement trajectory.

  The step of determining the moving direction based on the energy change at different times is shown in FIG. In step S801, the apparatus first acquires the energy received by each guidance unit at the previous and subsequent times (t0, t1). Next, as in step S803, the average value of the energy received by all or part of the energy at the previous and subsequent times is calculated. Each induction unit can calculate the energy change at the preceding and succeeding times as in step S805 after comparing the numerical value of energy acquired at different times (which can be displayed as a voltage signal) with the average numerical value.

  Thereafter, as in step S807, the energy change of the induction unit at different times (t0, t1) can be referenced to determine the direction of the energy change at the preceding and following times. Finally, as in step S809, the overall movement vector can be determined based on the energy change direction of the plurality of guidance units.

  In the method of determining the movement vector based on the change in the energy before and after described in FIG. 8, the energy before and after the induction unit may be in an energy state expressed in a voltage format. For example, after comparing with the whole energy average value at the same time, the energy state represented by one H or L shown in FIG. 6 can be acquired. Accordingly, first, each induction unit determines the energy state between the first time (t0) and the second time (t1), and then the induction unit determines the energy state from the first time to the second time. Changes to the statistical average value before and after the collection time can be obtained to determine the movement vector.

  The movement vector can be determined by referring to a schematic diagram in which a plurality of guiding units in the apparatus disclosed in the present invention shown in FIG.

  This example shows a combination of induction units 601, 602, 603, 604, 605, and 606 arranged in a plurality of arrays, but in this example, the adjacent induction units have different times (for example, the first time t0). In this example, the movement vector is identified based on the energy change sensed at the second time t1).

  Among them, t0 and t1 are two sampling times before and after, and H and L respectively denote high or low voltage signals output by the comparator, that is, energy state (one energy with respect to average energy). State). One overall movement vector is determined mainly by voltage signal conversion at the front and rear times. FIG. 6 shows the energy change at two different times before and after the individual guidance unit.

  For example, several (at least two) induction units are schematically shown in the combination 601 of the induction units. In the figure, the left side shows that when the first time t0, the two induction units induced two energy states of L and H separately. At the second time t1, the energy change of the two induction units is converted into H and H. When L and H (t0) change to H and H (t1), the energy state of one of the induction units changes from L to H, and the right H shows a shift to the left position. Therefore, it is possible to determine fundamentally that the moving direction of the effective guidance is left at this time interval.

  The other induction unit of this induction unit combination 601 has an energy state of H and L at t0 of the first time. At t1 of the second time, the energy state becomes L and L. The energy state of one of the induction units changes from H to L, that is, L on the right side shows a shift to the left side position. Therefore, it can be determined that there is a moving direction to the left.

  Further, for example, the left two induction units in the combination 602 of the induction unit have L and H energy states at t0 at the first time, and change to L and L at t1 at the second time. It can be seen that the H of the left shifts to the right through L on the left side. Therefore, it can be determined that there is a rightward movement vector.

  Similarly, in the two induction units on the right side in the induction unit combination 602, the energy states at the first time t0 are H and L, and then change to H and H at the second time t1, L on the right side of H is shifted to H via H on the left side. Therefore, it can be determined that there is a rightward movement vector.

  In the figure, the guidance unit combinations 605 and 606 do not indicate directions with arrows. As a result of the determination, in this example, the plurality of guidance units have no energy change in the time interval between the first time t0 and the second time t1, or cannot determine the moving direction based on the energy change. For example, in the induction unit combination 606, the energy state is L and H at the first time t0, and the energy state is changed to H and L at the second time t1. This makes it impossible to determine the direction of movement due to the energy state change. Therefore, these two modes have no valid output signal.

  When all the guidance units at the two times before and after determine the direction of energy change, one total movement vector can be determined as a whole.

  Another method of determining the moving direction is another schematic diagram of a ray tracing method performed by the medium guiding chip of the apparatus disclosed in the present invention, as shown in FIG. This example is a schematic diagram for identifying the method of the movement vector according to the direction of change of the energy state of the guidance unit at different times, where X is a value that does not care, @ is the ratio of the t0 and t1 sensed signals Thus, the movement vector is determined.

  When the induction chip receives the reflected light, when the average energy is compared with the signal energy received by the plurality of induction units in the induction chip at different times, different voltage signals are generated, as shown in FIG. In some cases, some inductive units have no energy change or are independent of the level of the voltage signal. At this time, as shown in FIG.

  According to the embodiment shown in FIG. 7, in the induction unit combination 701, the comparator obtains the energy change of the induction unit adjacent at the first time t0, and indicates the state “X @@”. "X" in the inside is a value that does not matter, and "@" indicates that there is a voltage change. Energy changes of a plurality of adjacent guidance units are acquired at the second time t1 and indicated by the state “@@ X”. This example shows that the state changes from the state “X @@” to “@@ X” due to the energy state change of each induction unit at the first time t0 and the second time t1. Since it can be determined that “@@” shifts to the left (shift), it can be determined that the combination 701 of the guidance unit has a change in movement to the left as indicated by an arrow in the figure.

  In the induction unit combination 702, the energy change of the adjacent induction unit at the first time t0 is indicated by the state “@@ X”, and at the second time t1, the energy state is indicated by “X @@”. Yes. At this time, after the time change (from t0 to t1), the state "@@" indicates that there is a shift trend to the right. Therefore, the tracking method disclosed by the present invention determines the movement direction of the entire apparatus based on the energy change at the preceding and following times.

  Incidentally, when determining the moving direction, the present invention employs a sensor array, so that a small error does not affect the overall determination result. When the tracking method is applied to an optical mouse of a computer, the frequency at which a general user operates and moves the mouse is much lower, for example, due to the processing speed of the control circuit inside, so the reference value that changes to slow is Does not affect judgment.

  In summary, the present invention provides a method for ray tracing by reflection interference and its ray tracing device, in which the disclosed ray tracing device is integrated in a semiconductor package, thereby causing intrinsic noise (intrinsic noise). Can be efficiently suppressed. And the apparatus which adapts the tracking method employ | adopts especially coherent light as a light source. Coherent light can improve the sensitivity of an optical sensor that senses reflected light interference.

  What has been described above is the preferred implementation of the present invention, but what should be explained is that for ordinary employees in the field, some improvements and modifications will occur as long as the principles of the present invention are not reversed. You can also. These improvements and modifications are considered to fall within the protection scope of the present invention.

Claims (10)

The induction chip receives reflected light reflected from the surface, and includes a plurality of induction units in which the induction chip is arranged geometrically symmetrically.
Each guidance unit calculates the energy received by each guidance unit by the light received before and after the time interval,
Calculate the energy state of all or some induction units before and after the time interval, and the energy state of the induction unit in the induction chip before and after the time interval is relative to the statistical average value before and after the collection time. A ray tracing method characterized by determining a movement vector based on a change.   The ray tracing method according to claim 1, wherein the reflected light is a light ray having good spatial coherence.   3. The ray tracing method according to claim 2, wherein the reflected light is obtained when a light ray emitted from a light source device is incident on the surface.   4. The ray tracing method according to claim 3, wherein the light source device is a laser beam device provided in an optical pointing device.   5. The ray tracing method according to claim 4, wherein the guide chip is a sensor array of the plurality of guide units arranged in an array, and is provided in the optical pointing device to receive the reflected light.   6. The ray tracing method according to claim 5, wherein the movement trajectory is determined by repeating the steps of the ray tracing method and calculating movement vectors at a plurality of time intervals. The calculation step of the energy state at the first time or the second time is the time interval from the first time and the second time.
Calculating an average value of energy received by all or some of the guidance units;
The difference between the energy received by each induction unit and the average value is calculated, and the difference includes a step for each induction unit to calculate the energy state at the first time or the second time. The ray tracing method according to claim 1. The step of calculating the change of the energy state before and after the time interval of the guidance unit with respect to the statistical average value before and after the collection time is as follows:
Determining the energy state of each induction unit at the first time;
Determining the energy state of each guidance unit at the second time;
The energy state from the first time to the second time of the guidance unit acquires a change with respect to a statistical average value before and after the collection time, and determines the movement vector. Ray tracing method. A ray tracing device using the ray tracing method according to claim 1,
A light source device for generating light incident on the surface;
A sensor array having the plurality of guidance units arranged in an array;
, Couple the light source device and the sensor array, acquire the optical signals received by the plurality of induction units, calculate the energy state, and statistics before and after the collection time for the energy state before and after the time interval of the induction unit And a controller for calculating a change in average value
A ray tracing device, wherein the sensor array and the controller are integrated in a semiconductor circuit, and the light source device, the integrated sensor array, and the controller are sealed on a circuit board in the ray tracing device.   The ray tracing method according to claim 9, wherein the ray tracing device is an optical pointing device using a laser beam as a light source.