This application claims priority to Japanese Patent Application No. 2013-079712 filed on Apr. 5, 2013. The entire disclosure of Japanese Patent Application No. 2013-079712 is hereby incorporated herein by reference.
1. Field of the Invention
This invention generally relates to an image projection device and an input object detection method.
2. Background Information
Conventionally, a projector for detecting input with a finger or other such input object is well-known in the art (see Japanese Unexamined Patent Application Publication No. 2009-258569 (Patent Literature 1), for example).
For example, with the conventional projector, an infrared laser is emitted from a light source. The infrared laser is scanned by part of a projector scanning means that projects a two-dimensional image, and is made parallel to the projection surface by reflection at a reflecting mirror. When the projected image is then touched by a finger, the infrared laser reflected by the finger is incident on a photodiode. The distance of the finger is measured by TOF (Time of Flight) method by a range finding means.
It has been discovered that with the conventional projector, if an object other than a finger is located on the projection surface, and the object is tall enough to reflect the infrared laser, then the object is mistakenly detected as a finger.
One aspect is to provide an image projection device with which it is less likely that an object other than an input object is mistakenly detected as an input object.
In view of the state of the known technology, an image projection device is provided that includes a projection component, a photodetector, and a determination component. The projection component is configured to project an image by scanning light beams two-dimensionally. The photodetector is configured to detect reflected lights obtained in response to the light beams being reflected by a reflecting object. The determination component is configured to determine whether or not the reflecting object is an input object based on whether or not a difference of light detection positions of the light beams is at least a specific value. The light detection positions are indicative of irradiation positions of the light beams in a projection region of the image, respectively.
Also other objects, features, aspects and advantages of the present disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses one embodiment of the image projection device and the input object detection method.
Referring now to the attached drawings which form a part of this original disclosure:
Selected embodiments will now be explained with reference to the drawings. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the embodiments are provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
Referring initially to
As shown in
As shown in
The input object is not limited to the touch pen 50. If the projected image 101 is touched with a finger, for example, then the laser light is also scattered and reflected by the finger. As a result, a touch by the finger can also be detected.
The laser unit 2 includes a red LD (Laser Diode) 2A, a collimator lens 2B, a green LD 2C, a blue LD 2D, collimator lenses 2E and 2F, beam splitters 2G and 2H, a horizontal MEMS (Micro Electro Mechanical System) mirror 2I, a vertical MEMS mirror 2J, a red laser control circuit 2K, a green laser control circuit 2L, a blue laser control circuit 2M, a mirror servo 2N, and an actuator 2O.
The red LD 2A emits a red laser light at a power level controlled by the red laser control circuit 2K. The red laser light thus emitted is made into a parallel beam by the collimator lens 2B, is transmitted through the beam splitters 2G and 2H, and heads toward the horizontal MEMS mirror 2I.
The green LD 2C emits a green laser light at a power level controlled by the green laser control circuit 2L. The green laser light thus emitted is made into a parallel beam by the collimator lens 2E, is reflected by beam splitter 2G, is transmitted through the beam splitter 2H, and heads toward the horizontal MEMS mirror 2I.
The blue LD 2D emits a blue laser light at a power level controlled by the blue laser control circuit 2M. The blue laser light thus emitted is made into a parallel beam by the collimator lens 2F, is reflected by the beam splitter 2H, and heads toward the horizontal MEMS mirror 2I.
The laser light incident on and reflected by the horizontal MEMS mirror 2I. The horizontal MEMS mirror 2I deflects the laser light so that it scans in the horizontal direction. Then, the laser light is incident on and reflected by the vertical MEMS mirror 2J. The vertical MEMS mirror 2J deflects the laser light so that it scans in the vertical direction. Then, the laser light is emitted to the outside through the window 1A in the housing of the projector 1, as shown in
The deflection by the horizontal MEMS mirror 2I and the vertical MEMS mirror 2J causes the visible laser light, such as a color composite laser light, emitted from the laser unit 2 to be scanned two-dimensionally.
Image data is stored in the memory 5. The memory 5 can be a ROM, for example, so that the image data is stored in the ROM. The memory 5 can also be a rewritable flash memory, for example, so that image data inputted from outside the projector 1 is stored in the flash memory.
The image data read by the controller 4 from the memory 5 is converted by the image data processor 3 into data for three colors, namely, red (R), green (G), and blue (B). Then, the converted data is sent to the red laser control circuit 2K, the green laser control circuit 2L, and the blue laser control circuit 2M, respectively.
In the illustrated embodiment, the controller 4 can includes a microcomputer or processor that controls various parts of the projector 1 as discussed below. The controller 4 can also include other conventional components such as an input interface circuit, an output interface circuit, and storage devices such as a ROM (Read Only Memory) device and a RAM (Random Access Memory) device. The microcomputer of the controller 4 is programmed to control the various parts of the projector. The storage devices store processing results and control programs. Specifically, the internal RAM stores statuses of operational flags and various control data. The internal ROM stores the programs for various operations. The controller 4 is capable of selectively controlling various parts of the projector 1 in accordance with the control program. It will be apparent to those skilled in the art from this disclosure that the precise structure and algorithms for controller 4 can be any combination of hardware and software that will carry out the functions of the present invention.
The mirror servo 2N deflects or drives the horizontal MEMS mirror 2I by driving the actuator 2O according to a horizontal synchronization signal from the controller 4. The mirror servo 2N also deflects or drives the vertical MEMS mirror 2J by driving the actuator 2O according to a vertical synchronization signal from the controller 4.
The horizontal synchronization signal is a sawtooth wave signal, for example. The vertical synchronization signal is a stair-step signal, for example.
In
As shown in
The photodetector 6 is used to detect whether or not an object located in the projected image 101 is the touch pen 50 or another such input object. The photodetector 6 includes a light receiving element 6A, a conversing lens 6B, and a flat masking member 6C. The light receiving element 6A detects irradiation by a reflected laser light. The converging lens 6B converges the reflected laser light incident from the window 1B and guides it to the light receiving element 6A. The flat masking member 6C is disposed between the light receiving element 6A and the converging lens 6B. The flat masking member 6C is tall enough to cover the lower part of the light receiving element 6A.
The photodetector 7 is used to detect a touch of the projected image 101 by the touch pen 50 or another such input object. The photodetector 7 is similar to the photodetector 6 in that it includes a light receiving element 7A, a converging lens 7B, and a flat masking member 7C. The conversing lens 7B converges the reflected laser light incident from the window 1C and guides it to the light receiving element 7A. The flat masking member 7C is disposed between the light receiving element 7A and the converging lens 7B. The flat masking member 7C is tall enough to cover the lower part of the light receiving element 7A.
As shown in
The spot of the reflected laser light is converged by the conversing lens 6B on the light receiving element 6A. However, generally, the spot of the reflected laser light from the ends of the projected image 101 becomes larger in diameter than the spot of the reflected laser light from the center of the projected image 101. Therefore, it is possible that what is supposed to be blocked by the masking member is not entirely be blocked because of an increase in spot diameter, and the light is instead received by the light receiving element 6A. This leads to false detection. In view of this, in the illustrated embodiment, the masking member 6C has a curved shape. Thus, the reflected laser light at the ends, which has a larger spot diameter, can be blocked while the spot diameter is small.
The detection ranges of the photodetectors 6 and 7 can be adjusted by adjusting the dimensions of the masking members 6C and 7C. An example of setting the detection ranges of the photodetectors 6 and 7 is indicated by the one-dot chain line in
Also, the upper limit U2 of the detection range of the photodetector 6 located at the upper level broadens so as to move away from the projection surface (in a direction perpendicular to the projection surface) as the distance from the projector 1 becomes larger in the vertical direction (the Y direction) of the projected image 101. Thus, the reflected laser light, obtained when the laser light is scanning the outer peripheral part E (see
Next, the processing for determining whether or not an object located on the projected image 101 of the projector 1 is the input object will be described through reference to
When the processing of the flowchart shown in
On the other hand, if reflected laser light is detected in one frame (Yes in step S1), then the flow proceeds to step S2. The controller 4 determines the light detection positions based on the detection signal from the photodetector 6 and the horizontal and vertical synchronization signals. The “light detection position” here means the irradiation position in the projected image 101 (or the projection region) of the laser light that is the origin of the reflected laser light that is detected, and is expressed by X and Y coordinate values.
In step S2, the controller 4 determines whether or not the determined light detection positions are continuous in the one frame, that is, whether or not the light detection positions form a group. If they are not continuous (No in step S2), then the flow returns to step S1. On the other hand, if the light detection positions are continuous (Yes in step S2), then the flow proceeds to step S3. Here, in the illustrated embodiment, the controller 4 can determine whether or not the light detection positions are continuously arranged in the one frame by determining whether or not the distance between each of adjacent pairs of the light detection positions is smaller than a predetermined threshold. For example, this threshold is set based on the line spacing of the lines of the laser light forming the projected image 101, such as two times of the line spacing and the like. Of course, this this threshold can be set in a different manner as needed and/or desired. If the controller 4 determines that the distance between each of the adjacent pairs of the light detection positions is smaller than the threshold, then the controller 4 determines that the light detection positions are continuously arranged in the one frame. Otherwise, the controller 4 determines that the light detection positions are not continuously arranged in the one frame or the light detection positions are arranged to form a plurality of groups that are spaced apart from each other.
As shown in
Meanwhile, as shown in
In step S3, the controller 4 determines whether or not the distal end (or the lower end, for example) of the detected reflecting object is located in the region R1. More specifically, the controller 4 determines whether or not the smallest (e.g., minimum) of the Y coordinate values of the determined light detection positions is greater than the boundary Y coordinate value. If it is greater, then the controller 4 determines the location to be in the region R1.
If the location is determined to be in the region R1 (Yes in step S3), then the flow proceeds to step S4. In step S4, the controller 4 determines whether or not a detection distance L1 (e.g., a difference) is at least a first determination criterion distance LB1 (e.g., a specific value). The detection distance L1 is calculated by the controller 4 as the difference between the smallest and largest (e.g., the minimum and maximum) of the Y coordinate values for the light detection positions. The first determination criterion distance LB1 is calculated by the controller 4 as the difference between the Y coordinate value of the outer peripheral part E of the projection region and the smallest Y coordinate value of the light detection positions. If the detection distance L1 is at least the first determination criterion distance LB1 (Yes in step S4), then it is determined that the detected reflecting object is a touch pen or other such input object (step S6). Otherwise (No in step S4), the reflecting object is determined not to be an input object, and the flow returns to step S1.
In
Meanwhile, in step S3, if the distal end of the detected reflecting object is located in the region R2 (No in step S3), then the flow proceeds to step S5.
In step S5, the controller 4 determines whether or not a detection distance L2 (e.g., a difference) is at least a second determination criterion distance LB2 (e.g., a specific value). The detection distance L2 is calculated by the controller 4 as the difference between the smallest and largest of the Y coordinate values for the light detection positions. The second determination criterion distance LB2 is calculated by the controller 4 as the difference between the smallest of the Y coordinate values of the light detection positions and the largest of the Y coordinate values of the light detection positions that is detected when an input object is disposed perpendicular to the projection surface at the distal end position of the detected reflecting object. In other words, as shown in
In
Thus, it is determined whether or not the reflecting object is an input object. If the reflecting object is an input object, then it is further determined that the projected image 101 is touched by the input object in response to the reflected laser light being detected by the photodetector 7.
As discussed above, the projector 1 includes the laser unit 2, the photodetector 6, and the controller 4. The laser unit 2 projects an image by two-dimensionally scanning a visible light beam. The photodetector 6 detects reflected light obtained when the visible light beam is reflected by a reflecting object. The controller 4 determines whether or not the reflecting object is an input object depending on whether or not the difference between the coordinate values of the light detection positions is at least a specific value (e.g., the first determination criterion distance or the second determination criterion distance).
Consequently, if the input object, such as the touch pen 50 or the like, inserted from outside the projection region is located in the projection region, then the difference of the coordinate values of the light detection positions is at least the specific value (e.g., the first determination criterion distance or the second determination criterion distance), and this object can be identified as an input object. If, however, a reflecting object other than an input object (the object 51 in
Also, in this embodiment, the controller 4 changes the above-mentioned specific value to the first determination criterion distance or the second determination criterion distance according to whether or not the light detection position is in the region R1. The region R1 is a region where reflected light of a light beam scanning the outer peripheral part E of the projection region is detected by the photodetector 6.
Consequently, even if the detection range of the photodetector 6 is made smaller, it is still be possible to determine that a reflecting object located in the region R2, where the outer peripheral part E of the projection region cannot be detected, is an input object. Also, since the photodetector 6 can be moved closer to the projection region, the projector 1 can be more compact.
Referring now to
In the first embodiment above, visible laser light is reflected by an input object and the reflected light is detected. Generally, if part of the projected image is black, then detection of the reflected black light from part of the input object located in the region R1 need to be sensitive. If the reflected black light is not detected, then the light detection positions can be determined not to be continuous (step S2 in
In view of this, with the projector 1′ in accordance with the second embodiment, the input object is reliably detected even in this case. In particular, with the projector 1′, as shown in
The infrared LD 2′A emits an infrared laser light at a power level controlled by the infrared laser control circuit 2′N. The infrared laser light thus emitted is made into a parallel beam by the collimator lens 2′B, is transmitted through the beam splitters 2′I, 2′J and 2′K, and heads toward the horizontal MEMS mirror 2′L.
The red LD 2′C emits a red laser light at a power level controlled by the red laser control circuit 2′O. The red laser light thus emitted is made into a parallel beam by the collimator lens 2′F, is reflected by the beam splitters 2′I, is transmitted through the beam splitters 2′J and 2′K, and heads toward the horizontal MEMS mirror 2′L.
The green LD 2′D emits a green laser light at a power level controlled by the green laser control circuit 2′P. The green laser light thus emitted is made into a parallel beam by the collimator lens 2′G, is reflected by beam splitter 2′J, is transmitted through the beam splitter 2′K, and heads toward the horizontal MEMS mirror 2′L.
The blue LD 2′E emits a blue laser light at a power level controlled by the blue laser control circuit 2′Q. The blue laser light thus emitted is made into a parallel beam by the collimator lens 2′H, is reflected by beam splitter 2′K, and heads toward the horizontal MEMS mirror 2′L.
The laser light is incident on and reflected by the horizontal MEMS mirror 2′L. The horizontal MEMS mirror 2′L deflects the laser light so that it scans in the horizontal direction. Then, the laser light is incident on and reflected by the vertical MEMS mirror 2′M. The vertical MEMS mirror 2′M deflects the laser light so that it scans in the vertical direction. Then, the laser light is emitted to the outside through a window in the housing of the projector 1′.
When the projected image 101 is projected, the infrared LD 2′A is extinguished, and a visible laser light that is color composite light produced by the red LD 2′C, the green LD 2′D, and the blue LD 2′E is scanned. The extinguishing of the infrared LD 2′A reduces power consumption. When the detection-use image 102 is projected, the red LD 2′C, the green LD 2′D, and the blue LD 2′E are extinguished, and the infrared laser light produced by the infrared LD 2′A is scanned.
The processing for determining an input object by the projector 1′ in this embodiment is the same as the processing in the first embodiment (
In addition to this, in this embodiment, the controller 4 determines that the reflecting object is an input object if the light detection positions detected by the photodetector 6 are included in the detection-use image 102. Even if part of the projected image 101 produced by the visible laser light is black and the reflected light from part of the input object cannot be detected, the infrared laser light projecting the detection-use image 102 can still be reflected by the input object and be reliably detected. Therefore, the input object can be detected more accurately.
When the infrared laser light is used for projecting the detection-use image 102 as above, the user cannot see the detection-use image 102 because it is non-visible light. However, a visible laser light can also be used for projecting the detection-use image 102. In this case, the visible light projecting the detection-use image 102 can be reflected by the reflecting object and reliably detected if the detection-use image 102 is all one color, such as white or red.
Also, in this case, no component will be needed to output infrared light. Thus, the same components as in the first embodiment (see
As mentioned-above, the laser unit 2′ projects the detection-use image 102 with the infrared laser light around the projected image 101 projected with the visible light beam.
There can be cases in which the projected image 101 projected with the visible light beam is black and the reflected light cannot be detected from part of the reflecting object. However, even if this happens, the reflected light from the reflecting object can be reliably detected by using the detection-use image 102 projected around the projected image 101. Therefore, it can be reliably determined that the reflecting object is an input object.
Referring now to
In this embodiment, the projector 1′ in accordance with the third embodiment includes the same configuration as with the projector 1′ in the second embodiment (see
When the processing of the flowchart shown in
If the reflected laser light is detected (Yes in step S12), then the flow proceeds to step S13. In step S13, when the next frame of the projected image 101 is projected with the visible laser light under the control of the controller 4, a detection-use image with an infrared laser light is projected in the region surrounding the light detection positions of the reflected laser light. The detection-use image with the infrared laser light is produced by the infrared LD 2′A.
In the illustrated embodiment, as shown in
After step S13, the flow returns to step S12. In step S12, if the reflected laser light is not detected in one frame (No in step S12), then the flow proceeds to step S14. In step S14, in the projection of the next frame of the image, no detection-use image is projected, and projection is performed with ordinary visible laser light. In the illustrated embodiment, step S11 of the image projection processing shown in
In this embodiment, the same processing as in the first embodiment (see
In this embodiment, the detection-use image can also be projected using the visible laser light. In this case, the detection-use image can be projected in one color, such as white or red. Also, in this case, no component is needed to output infrared light. Thus, the cost can be kept lower.
With this projector 1′, as a result of the projected image 101 being projected by the laser unit 2′ with the visible light beam, the laser unit 2′ projects the detection-use image with the infrared laser light in a region (e.g., the region S in
Therefore, although there can be cases when part of the projected image 101 projected with the visible light beam is black and the reflected light cannot be detected at part of the reflecting object, even in such a case, the detection-use image is projected with the infrared laser light in a region surrounding the reflecting object. Thus, the reflected light from the reflecting object can be reliably detected. Therefore, it can be reliably determined that the reflecting object is an input object.
Referring now to
In this embodiment, the projected image 101 (see
When part of the projected image 101 is projected black, the reflected laser light is not detected at part of the reflecting object. If this happens, the light detection positions can be determined not to be continuous (step S2) in the processing shown in
In view of this, with the projector 1 in accordance with the fourth embodiment, the input object detection processing shown in
For example, as shown in
In step S22, the controller 4 determines whether or not the plurality of light detection position groups determined in step S21 are at least partially arranged along a single straight line. If they are arranged along a single straight line (Yes in step S22), then the flow proceeds to step S23. Otherwise (No in step S22), the flow returns to step S21.
In the example in
In step S23, the controller 4 determines whether or not the specific range including one of the groups that is located at the end out of the plurality of light detection position groups is located outside the projection region of the projected image 101. If the location is outside the projection region (Yes in step S23), then the flow proceeds to step S24 and the controller 4 determines that the reflecting object is an input object. Otherwise (No in step S23), the flow returns to step S21.
In the example in
In the illustrated embodiment, the controller 4 determines that the reflecting object is an input object if, as a result of the projected image 101 being projected by the laser unit 2 with a visible light beam, there are a plurality of groups of obtained light detection positions (such as the groups G1 to G3 in
Consequently, although there can be cases when part of the projected image 101 projected with a visible light beam is black and light cannot be detected at part of the reflecting object, even in such a case, the reflecting object can be determined to be an input object because of the plurality of groups of light detection positions.
Also, in this embodiment, the controller 4 determines the reflecting object to be an input object if the plurality of groups are arranged on the single straight line. Consequently, it is possible to detect the input object having a linear shape, such as a touch pen or a finger. This makes it less likely that reflecting objects other than the input object that have a curved shape are mistakenly detected.
In the illustrated embodiments, the projector 1 or 1′ (e.g., the image projection device) includes the laser unit 2 or 2′ (e.g., the projection component), the photodetector 6, and the controller 4 (e.g., the determination component). The laser unit 2 or 2′ is configured to project the projected image 101 (e.g., the image) by scanning laser lights (e.g., the light beams) two-dimensionally. The photodetector 6 is configured to detect the reflected lights obtained in response to the laser lights being reflected by the reflecting object. The controller 4 is configured to determine whether or not the reflecting object is an input object, such as the touch pen 50, based on whether or not the difference L1 or L2 of the light detection positions of the laser lights is at least the distance LB1 or LB2 (e.g., the specific value). The light detection positions are indicative of irradiation positions of the laser lights in the projection region of the projected image 101, respectively.
With this configuration, if the reflecting object inserted into the projection region from outside the projection region is located in the projection region, then the difference L1 or L2 of the coordinate values of the light detection positions is at least the distance LB1 or LB2. Thus, this reflecting object can be identified as the input object. On the other hand, if the reflecting object other than the input object is located in the projection region, then the difference L1 or L2 of the coordinate values of the light detection positions is less than the distance LB1 or LB2. Thus, the reflecting object can be determined not to be the input object. Therefore, it is less likely that the reflecting object other than the input object will be mistakenly detected as the input object.
Also, in the illustrated embodiments, the determination component is configured to change the distance LB1 or LB2 based on whether or not at least one of the light detection positions is located in the region R1 in which a reflected light of the laser light that scans the outer peripheral part E of the projection region is detected by the photodetector 6.
With this configuration, even if the detection range of the photodetector 6 is made smaller, it will still be possible to determine that the reflecting object located in the region R2 where the outer peripheral part E of the projection region cannot be detected is the input object. Also, since the photodetector 6 can be moved closer to the projection region, the projector 1 or 1′ (e.g., the image projection device) can be more compact.
Also, in the above configuration, the laser unit 2 or 2′ is configured to project the projected image 101 with the visible light beam. The laser unit 2 or 2′ is further configured to project the detection-use image 102 with the specific light beam around the projected image 101.
With this configuration, there can be situations when part of the projected image 101 projected by the visible light beam is black and light cannot be detected in part of the reflecting object. However, even if that happens, the reflected light from the reflecting object can still be reliably detected by using the detection-use image 102 projected by the specific light beam around the image produced by the visible light beam. Therefore, it can be reliably determined that the reflecting object is the input object.
Also, in the above configuration, the laser unit 2 or 2′ is configured to project the projected image 101 with the visible light beam. The laser unit 2 or 2′ is further configured to project project the detection-use image with the specific light beam in the region S around the light detection positions.
With this configuration, there can be situations when part of the projected image 101 projected by the visible light beam is black and light cannot be detected in part of the reflecting object. However, even if that happens, the reflected light from the reflecting object can still be reliably detected since the detection-use image is projected by the specific light beam in the region S that surrounds the reflecting object. Therefore, it can be reliably determined that the reflecting object is the input object.
Also, in the above configuration, the specific light beam can include the non-visible light beam. With this configuration, since the detection-use image is projected by the non-visible light beam, it will have no effect on how the image produced by the visible light beam looks.
Also, in the above configuration, the specific light beam can include the visible light beam. With this configuration, since no component is needed for outputting the non-visible light beam, the cost can be kept lower.
Also, the controller 4 is further configured to determine that the reflecting object is the input object in response to determining that there are a plurality of groups G1, G2 and G3 of the light detection positions with each one of the groups G1, G2 and G3 being at least partially located within the specific range T that is defined around different one of the groups G1, G2 and G3, and that the specific range T defined around the group G3 that is located at end of the groups G1, G2 and G3 is at least partially located outside the projection region of the projected image 101.
With this configuration, there can be situations when part of the image projected by the visible light beam is black and light cannot be detected in part of the reflecting object. However, even if that happens, it can still be determined from the plurality of the groups G1, G2 and G3 of the light detection positions that the reflecting object is the input object.
Also, in the above configuration, the controller 4 is further configured to determine that the reflecting object is the input object in response to determining that the groups G1, G2 and G3 are arranged along a single straight line Ln. With this configuration, it will be possible to detect the input object having a linear shape, such as a touch pen or a finger, making it less likely that the reflecting object other than the input object with a curved shape will be mistakenly detected.
In the illustrated embodiments, the controller 4 is further configured to determine whether or not the light detection positions are continuously arranged in the projection region. The controller 4 is further configured to determine whether or not the difference L1 or L2 of the light detection positions is at least the distance LB1 or LB2 in response to determining that the light detection positions are continuously arranged in the projection region.
In the illustrated embodiments, the controller 4 is further configured to determine that the reflecting object is the input object in response to the difference L1 or L2 of the light detection positions is at least the distance LB1 or LB2.
In the illustrated embodiments, the controller 4 is further configured to calculate the difference L1 or L2 of the light detection positions by calculating a difference between the minimum and maximum Y coordinate values of the light detection positions.
In the illustrated embodiments, the controller 4 is further configured to calculate the distance LB1 by calculating a difference between the minimum Y coordinate value of the light detection positions and the coordinate value of the outer peripheral part E of the projection region.
In the illustrated embodiments, the controller 4 is further configured to calculate the distance LB2 by calculating a difference between the minimum Y coordinate value of the light detection positions and the coordinate value of the irradiation position of the laser light that passes through the intersection between the imaginary line (the touch pen 50 illustrated with the dotted line in
Also, in the illustrated embodiments, the input object detection method includes scanning laser lights (e.g., the light beams) two-dimensionally to project the projected image 101, detecting reflected lights obtained in response to the light beams being reflected by a reflecting object, and determining whether or not the reflecting object is an input object, such as the touch pen 50, based on whether or not the difference L1 or L2 of the light detection positions of the laser lights is at least the distance LB1 or LB2 (e.g., the specific value). The light detection positions are indicative of irradiation positions of the laser lights in the projection region of the projected image 101, respectively.
Also, the above configuration can further includes determining whether or not at least one of the light detection positions is located in the region R1 in which a reflected light of the laser light that scans the outer peripheral part E of the projection region is detected, and changing the distance LB1 or LB2 based on whether or not the at least one of the light detection positions is located in the region R1.
With the present invention, it is less likely that an object other than an input object will be mistakenly detected as an input object.
In understanding the scope of the present invention, the term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, “including”, “having” and their derivatives. Also, the terms “part,” “section,” “portion,” “member” or “element” when used in the singular can have the dual meaning of a single part or a plurality of parts unless otherwise stated.
As used herein, the following directional terms “frame facing side”, “non-frame facing side”, “forward”, “rearward”, “front”, “rear”, “up”, “down”, “above”, “below”, “upward”, “downward”, “top”, “bottom”, “side”, “vertical”, “horizontal”, “perpendicular” and “transverse” as well as any other similar directional terms refer to those directions of an image projection device in an upright position. Accordingly, these directional terms, as utilized to describe the image projection device should be interpreted relative to an image projection device in an upright position on a horizontal surface.
Also it will be understood that although the terms “first” and “second” can be used herein to describe various components these components should not be limited by these terms. These terms are only used to distinguish one component from another. Thus, for example, a first component discussed above could be termed a second component and vice-a-versa without departing from the teachings of the present invention. The term “attached” or “attaching”, as used herein, encompasses configurations in which an element is directly secured to another element by affixing the element directly to the other element; configurations in which the element is indirectly secured to the other element by affixing the element to the intermediate member(s) which in turn are affixed to the other element; and configurations in which one element is integral with another element, i.e. one element is essentially part of the other element. This definition also applies to words of similar meaning, for example, “joined”, “connected”, “coupled”, “mounted”, “bonded”, “fixed” and their derivatives. Finally, terms of degree such as “substantially”, “about” and “approximately” as used herein mean an amount of deviation of the modified term such that the end result is not significantly changed.
While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. For example, unless specifically stated otherwise, the size, shape, location or orientation of the various components can be changed as needed and/or desired so long as the changes do not substantially affect their intended function. Unless specifically stated otherwise, components that are shown directly connected or contacting each other can have intermediate structures disposed between them so long as the changes do not substantially affect their intended function. The functions of one element can be performed by two, and vice versa unless specifically stated otherwise. The structures and functions of one embodiment can be adopted in another embodiment. It is not necessary for all advantages to be present in a particular embodiment at the same time. Every feature which is unique from the prior art, alone or in combination with other features, also should be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts embodied by such feature(s). Thus, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
Number | Date | Country | Kind |
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2013-079712 | Apr 2013 | JP | national |