JP2012108233A - Electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic device allowing a user himself or herself to know a detected touch position.SOLUTION: The electronic device comprises: first light sources 201-203 radiating light of visible wavelength for projection; a light valve 204 modulating radiated light from the first light sources 201-203; a projection optical system 205 projecting an image produced by modulation light from the light valve 204; a second light source 12, differing from the first light sources 201-203, radiating light of visible wavelength approximately in parallel with a projection surface of the projection optical system 205; imaging means 11 acquiring a first image which corresponds to visible wavelength from the second light source 12 and includes a projection area by the projection optical system 205; detecting means 15 detecting changes among images based on the first images which are acquired by the imaging means 11 at predetermined intervals; and instructing means 15 instructing a predetermined process based on the detected position in the first image.

Description

  The present invention relates to an electronic device.

  A technique is known in which an image is projected by a projector and a position where the projected image is touched with a finger or the like is detected (see Patent Document 1).

JP 2009-2558569 A

  In the prior art, since invisible light is used as the detection light for the touch position, there is a problem that even if the user's finger touches the detection light, the user himself / herself does not know.

  An electronic apparatus according to the present invention includes a first light source that emits light having a visible wavelength for projection, a light valve that modulates illumination light from the first light source, a projection optical system that projects an image of the modulated light from the light valve, Unlike the first light source, the second light source emits light having a visible wavelength substantially parallel to the projection surface by the projection optical system, and an image corresponding to the visible wavelength by the second light source, including a projection region by the projection optical system. An imaging unit that acquires one image, a detection unit that detects a change between images based on a first image that the imaging unit acquires at predetermined intervals, and an instruction that instructs a predetermined process based on a detection position in the first image And means.

  In the electronic device according to the present invention, the touch position can be detected so that the detected touch position can be recognized by the user.

It is a principal part block diagram of the optical system of the projector by one embodiment of this invention. It is a figure explaining the optical system (state of a projection period) of a projector in detail. It is a figure which illustrates the state of a detection period. It is a figure explaining the light emission timing of a laser light source and a light emission unit. It is a flowchart explaining the flow of the process which a control part performs. It is a figure explaining the light emission timing of the laser light source in the modification 5, and the light emission unit. It is a principal part block diagram of the optical system (state of a projection period) of the projector in the modification 6. It is a figure which illustrates the state of a detection period.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a main part of an optical system of a projector 1 according to an embodiment of the present invention. In the present embodiment, the projector 1 projects the installation surface. In FIG. 1, the projector 1 includes a projection unit 20, a control unit 15, a visible camera 11, a light projecting unit 12, and a reflection mirror 30.

  FIG. 2 is a diagram for explaining the optical system of the projector 1 in detail. In FIG. 2, the projection unit 20 includes laser light sources 201, 202, 203, a reflective display element 204, and a projection optical system 205. The laser light source includes, for example, a semiconductor laser that emits red light (hereinafter referred to as LD 201), an LD 202 that emits green light, and an LD 203 that emits blue light, and constitutes a three-primary-color light source. The laser light sources 201, 202, and 203 illuminate the reflective display element 204 in color sequence by emitting each color in a time division manner.

  The reflective display element 204 is configured by, for example, a DMD (Digital Micromirror Device). The DMD is a two-dimensional array of movable micromirror surfaces (micromirrors) corresponding to pixels. By driving an electrode provided on the micromirror, a state in which the illumination light is reflected toward the projection optical system and a state in which the illumination light is reflected toward the internal absorber are switched. By driving each micromirror individually, the reflection of illumination light is controlled for each display pixel.

  In general, DMD is a binary control of a state in which illumination light is reflected to the outside and a state in which illumination light is absorbed to the inside. However, these binary states are switched at high speed, and the time ratio between the reflection state and the absorption state is changed. The shade is expressed by the pulse width modulation (PWM) to be controlled. By illuminating the laser light sources 201, 202, and 203 in color order, a full color image is projected using one reflective display element 204. The projection light beam emitted from the projection unit 20 via the projection optical system 205 is bent by the reflection mirror 30 (FIG. 1). Thereby, a full color image is projected on the projection area | region of a installation surface (screen).

  The image signal projected by the projection unit 20 is supplied from the external device to the control unit 15 of the projector 1. The control unit 15 controls the projection unit 20 by driving the reflective display element 204 based on an image signal from an external device and causing the laser light sources 201, 202, and 203 to emit light.

  Since the present embodiment has a feature in touch position detection when a full color image projected by the projector 1 is touched with a finger or the like, the following description will be focused on touch position detection.

  The control unit 15 performs drive control on the visible camera 11 and the light projecting unit 12 in addition to the projection control. The visible camera 11 captures a projection area by the projection unit 20, that is, a projected full color image. The control unit 15 acquires an image captured by the visible camera 11 as an image signal of the projection image, and when the trapezoidal distortion occurs in the image, displays it on the reflective display element so as to eliminate the trapezoidal distortion. Correct the image. Thereby, trapezoidal distortion correction is performed on the image projected from the projection unit 20. In addition, the control unit 15 acquires an image captured by the visible camera 11 as an image signal of the projection image, and individually adjusts the density of the color component that is excessive or insufficient when color correction of the image is necessary. Thus, color correction of the projected image is performed. For example, when the projector 1 is placed on a desk, color correction may be necessary due to the color of the desk.

  The light projecting unit 12 is configured by an LED that emits visible light (for example, red light). The light projecting unit 12 emits a light beam parallel to the installation surface in response to an instruction from the control unit 15. Since the red light from the light projecting unit 12 does not irradiate the installation surface, the red light does not affect the projection image by the projection unit 20.

  The light projecting unit 12 emits light by shifting the light emission timing of the LD 201, LD 202, and LD 203 constituting the laser light source described above. FIG. 4 is a diagram illustrating the light emission timing of the LEDs of the LD 201, LD 202, LD 203, and the light emitting unit 12. In FIG. 4, the horizontal axis represents time, and the vertical axis represents the on / off state of each light source. Each light source emits light in the on state and turns off in the off state. According to FIG. 4, the blue LD 203, the green LD 202, and the red LD 201 emit light sequentially in color for each frame of the image to be projected (referred to as a projection period). Then, before the blue LD 203 emits light for projection of the next frame, the light projecting unit 12 emits light (referred to as a detection period).

  That is, during the projection period, the blue LD 203, the green LD 202, and the red LD 201 emit light in a time-sharing manner for each predetermined time (for example, 8 msec). And in the detection period sandwiched between the projection period and the projection period, the visible light LED of the light projecting unit 12 emits light for a predetermined time (for example, 8 msec). FIG. 1 is a diagram illustrating the state of the projection period, and FIG. 3 illustrates the state of the detection period. When the user touches a predetermined area indicated by a full-color image with a finger or the like, the projection period of FIG. 1 and the detection period of FIG. 3 are alternately repeated, so that the fingertip blocks the light beam from the light projecting unit 12. Visible light (red light in this example) is diffusely reflected by the fingertip. Part of the reflected light of the visible light travels toward the visible camera 11.

  By causing the visible camera 11 to perform imaging in the detection period illustrated in FIG. 3, it is possible to acquire a detection image including visible light (red light) reflected by the finger. The control unit 15 acquires an image captured by the visible camera 11 as an image signal of the detection image, detects a position coordinate (a pixel position having the highest luminance in the screen) where the red light is reflected in the acquired image, Predetermined processing is performed based on the detection position.

  As an example of the predetermined process, for example, when the detection position is included in the left area of the shooting screen, the image projected by the projection unit 20 is returned to the previous frame. On the contrary, when the detection position is included in the right area of the shooting screen, the image projected by the projection unit 20 is advanced by one frame.

  FIG. 5 is a flowchart for explaining the flow of processing executed by the control unit 15. When the power on operation of the projector 1 is performed, the control unit 15 activates the process illustrated in FIG. In this embodiment, an initial check (referred to as a first imaging mode) is performed after startup, and when the initial check is completed, a transition is made to a normal operation (referred to as a second imaging mode).

  In the first imaging mode, the visible camera 11 captures a projection image during the projection period, and imaging by the visible camera 11 is omitted during the detection period. In contrast, in the second imaging mode, shooting by the visible camera 11 is omitted during the projection period, and the visible camera 11 captures a detection image during the detection period.

  In step S1 of FIG. 5, the control unit 15 sends an instruction and data to the projection unit 20, displays an initial image on the reflective display element, and proceeds to step S2. Thereby, an initial image is projected on the projection area which is an installation surface. For example, a known check pattern for distortion check and white balance check is used as the initial image.

  In step S2, the control unit 15 acquires the projection state. Specifically, an instruction is sent to the visible camera 11, the initial image projected by the projection unit 20 is photographed during the projection period, and the process proceeds to step S3. In step S3, the control unit 15 performs image determination. Specifically, a check pattern image captured by the visible camera 11 is acquired to perform a distortion check, and a white balance check is performed based on the check pattern image. If the result of the check is good, the control unit 15 makes a positive determination in step S3 and proceeds to step S4. If the result of the check is negative, the control unit 15 makes a negative determination in step S3 and returns to step S2. When returning to step S2, after performing the above-mentioned trapezoidal distortion correction and color correction (white balance correction), the initial image is taken again.

  Note that the control unit 15 also makes a negative determination in step S3 when the image acquired from the visible camera 11 cannot be recognized as a check pattern image due to the presence of an obstacle on the projection area that is the installation surface.

  In step S4, the control unit 15 switches from the first imaging mode to the second imaging mode, and proceeds to step S5. Specifically, shooting of the visible camera 11 in the subsequent projection period is stopped, and shooting of the visible camera 11 is started in the subsequent detection period. Thereby, the projector 1 shifts to the normal operation.

  In normal operation, while projecting an image from the projection unit 20, visible light is emitted from the light projecting unit 12 during a detection period sandwiched between the projection period and the projection period, and an image is acquired by the visible camera 11 during the detection period. Repeat the operation. The control unit 25 according to the present embodiment checks whether there is a change between frames of the color (red) image emitted by the light projecting unit 12, and if a change is detected, the touch position is based on the acquired image as described above. Is detected.

  In step S5, the control unit 15 sends an instruction to the light projecting unit 12 to emit visible light (red light in this example). The control unit 15 further sends an instruction to the projection unit 20 to project a predetermined image supplied from the external device to the projector 1. Note that an image stored in a nonvolatile memory in the control unit 15 may be projected.

  When the user touches the projection area with a finger or the like, the control unit 15 performs a predetermined process based on the touch position as described above. When the projection area is not touched, the projection of the predetermined image is continued.

  In step S6, when the image projection stop operation is performed, the control unit 15 proceeds to step S7. In step S7, the control unit 15 sends an instruction to the projection unit 20, ends the image projection, and ends the process shown in FIG.

According to the embodiment described above, the following operational effects can be obtained.
(1) The projector 1 includes laser light sources 201, 202, and 203 that emit red, green, and blue light, a reflective display element 204 that modulates illumination light from the laser light sources 201, 202, and 203, and a reflective display. Unlike the projection optical system 205 that projects an image of modulated light from the element 204 and the laser light sources 201, 202, and 203, the light projecting unit 12 that emits light having a visible wavelength substantially parallel to the projection surface of the projection optical system 205; Based on an image corresponding to a visible wavelength by the light projecting unit 12 and acquiring a detection image including a projection area by the projection optical system 205, and a detection image acquired by the visible camera 11 at a predetermined interval. A control unit 15 that detects a change between images, and a control unit 15 that instructs a predetermined process based on a detection position in the detection image; Since the touch position detected can be performed to detect the touch position as can be seen in the user's own.

(2) In the projector 1, the laser light source 201 emits light when the laser light sources 201, 202, and 203 are not emitting light, and emits light when the light projecting unit 12 is not emitted. 202, 203 and the control unit 15 for controlling the light projecting unit 12 can be further provided, so that an imaging unit for a general digital camera can be used as the visible camera 11, and an image for detection can be appropriately acquired. You can also.

(3) In the above (2), the control unit 15 causes the laser light sources 201, 202, 203, the light projecting unit 12, and the laser light source 201, 202, 203 so that the visible camera 11 acquires a detection image in a state where the light projecting unit 12 emits light. Since the visible camera 11 is controlled, a detection image can be appropriately acquired.

(4) In the above (3), the control unit 15 further performs laser processing so as to acquire an image corresponding to a visible wavelength by the laser light sources 201, 202, and 203 and including a projection area by the projection optical system 205. Since the light source 201, 202, 203, the light projecting unit 12, and the visible camera 11 are further controlled and the control unit 15 that corrects the image projected from the projection optical system 205 based on the acquired projection image is provided, the visible camera 11 is provided. Besides the touch position detection, it can be used for correcting the projected image.

(5) In the above (1) to (4), the laser light source includes light sources 201, 202, and 203 of different colors having different wavelengths, and the controller 15 time-divides the light sources 201, 202, and 203 of different colors. Since the light emitting unit 12 emits light and all the light sources 201, 202, and 203 of the plurality of colors emit light when no light is emitted, an image for detection can be acquired appropriately.

(6) In the above (5), since the laser light source includes red, green, and blue light sources, a full color image can be obtained as a projection image.

(Modification 1)
As a light source of the projection unit 20, an LED light source may be used instead of the laser light source. Further, as the visible light source of the light projecting unit 12, an LD light source may be used instead of the LED light source.

(Modification 2)
About the light which the light projection unit 12 for detecting the touch position of a projection area | region emits visible light, it may not be red light.

(Modification 3)
In the above description, the example in which the light projecting unit 12 continuously emits light has been described. However, instead of continuous light emission, blinking light emission may be performed. For example, as described above, when the image projected by the projection unit 20 based on the touch position is moved back or forward, the first frame is already being projected and cannot be returned to the front, or the last frame is already being projected. If the light cannot be sent next time, the light emitted from the light projecting unit 12 is switched from continuous light to blinking light. By changing the light diffusely reflected by the user's fingertip to blinking light, the user can be informed that frame return or frame advance is impossible. Even when the light projecting unit 12 emits flashing light, the touch position can be detected in the same manner as in the case of continuous light emission.

(Modification 4)
When the power source battery (not shown) of the projector 1 is exhausted and the remaining capacity becomes a predetermined value or less, or when the temperature in the projection unit 20 exceeds the predetermined temperature, the light projecting unit 12 may be caused to flash. Good. By changing the light diffusely reflected by the user's fingertip to blinking light, it is possible to notify the user of a decrease in the remaining battery level or an increase in the temperature in the device.

(Modification 5)
The light emission timing of the light projecting unit 12 may be different from that in FIG. When there is a state where none of the LD 201, LD 202, and LD 203 constituting the laser light source described above emits light, the light projecting unit 12 may emit light during this period. FIG. 6 is a diagram for explaining the light emission timing of the LEDs of the LD 201, LD 202, LD 203, and the light emitting unit 12 in the fifth modification. In FIG. 5, the horizontal axis represents time, and the vertical axis represents the on / off state of each light source. Each light source emits light in the on state and turns off in the off state.

  According to FIG. 6, there are three periods in which none of the blue LD 203, the green LD 202, and the red LD 201 emits light per image frame to be projected. Therefore, the light projecting unit 12 is caused to emit light at least once among these three times. For example, when one frame is set to about 16.67 msec (60 Hz), the blue LD 203, the green LD 202, and the red LD 201 are spaced apart from each other by a first predetermined time (eg, 1.11 msec) for a second predetermined time ( For example, 4.44 msec). The light projecting unit 12 emits visible light during the first predetermined time. In the modification 5, the 1st predetermined time when the light projection unit 12 emits visible light is equivalent to the said detection period.

(Modification 6)
The visible camera 11 may be changed to a higher position with respect to the installation surface. 7 and 8 are main part configuration diagrams of the optical system of the projector 1B according to the sixth modification. FIG. 7 illustrates a state corresponding to the projection period, and FIG. 8 illustrates a state corresponding to the detection period.

  7 and 8, the same reference numerals are used for members common to those in FIGS. In the modified example 6, since the visible camera 11 is farther from the installation surface than in the case of FIGS. 1 and 3, the shooting angle of view when shooting the projection area can be kept small. If the photographic angle of view is small, the photographic optical system can be miniaturized, leading to miniaturization of the visible camera 11 and consequently miniaturization of the projector 1B.

  Although the projector 1 has been described as an example, the present invention can also be applied to electronic devices such as a camera, a mobile phone, and a photo frame.

  The above description is merely an example, and is not limited to the configuration of the above embodiment.

DESCRIPTION OF SYMBOLS 1, 1B ... Projector 11 ... Visible camera 12 ... Projection unit 15 ... Control part 20 ... Projection unit 30 ... Reflection mirror 201, 202, 203 ... Laser light source 204 ... Reflective display element 205 ... Projection optical system

Claims (7)

A first light source that emits light of a visible wavelength for projection;
A light valve that modulates illumination light from the first light source;
A projection optical system for projecting an image of modulated light from the light valve;
Unlike the first light source, a second light source that emits light having a visible wavelength substantially parallel to a projection surface by the projection optical system;
An imaging unit that acquires an image corresponding to a visible wavelength by the second light source and includes a projection region by the projection optical system;
Detecting means for detecting a change between images based on the first image acquired by the imaging means at predetermined intervals;
Instruction means for instructing predetermined processing based on the detection position in the first image;
An electronic device comprising: The electronic device according to claim 1,
Control means for controlling the first light source and the second light source so that the second light source emits light when the first light source does not emit light and the first light source emits light when the second light source does not emit light. An electronic device characterized by that. The electronic device according to claim 2,
The control unit controls the first light source, the second light source, and the imaging unit so that the imaging unit acquires the first image in a state where the second light source emits light. Electronics. The electronic device according to claim 3,
The control means further includes the first light source, the second light source, and the imaging so as to obtain an image corresponding to a visible wavelength by the first light source and including a projection region by the projection optical system. Control means,
An electronic apparatus, further comprising a correcting unit that corrects an image projected from the projection optical system based on the second image. In the electronic device as described in any one of Claims 1-4,
The first light source includes a plurality of color light sources having different wavelengths.
The control device causes the light sources of the plurality of colors to emit light in a time-sharing manner, and causes the second light source to emit light when all of the light sources of the plurality of colors do not emit light. The electronic device according to claim 5,
The electronic device according to claim 1, wherein the first light source includes red, green, and blue light sources. The electronic device according to claim 2,
The electronic device is characterized in that the control means further varies the light emission mode of the second light source according to at least one of a remaining battery level and a temperature in the device.

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