JP2012108232A - Electronic device - Google Patents

Abstract

To detect a touch position detected by a user himself / herself.
An electronic device projects a first light source that emits light of a first visible wavelength, a light valve that modulates illumination light from the first light source, and an image that is modulated light from the light valve. A projection optical system 20, a second light source 14 that emits light having a second visible wavelength different from the first visible wavelength, substantially parallel to the projection surface of the projection optical system 20, and an image corresponding to the second visible wavelength, An imaging unit 11 that acquires a first image including a projection area by the optical system 20, a detection unit 25 that detects a change between images based on a first image that the imaging unit 11 acquires at a predetermined interval, and a first image And instructing means 25 for instructing predetermined processing based on the detection position.
[Selection] Figure 2

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 first visible wavelength, 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, A second light source that emits light of a second visible wavelength different from the first visible wavelength substantially parallel to the projection surface of the projection optical system, and an image corresponding to the second visible wavelength, 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 which illustrates the state in which a yellow transmissive filter is located on an optical path. It is a figure which illustrates the spectral characteristic about each color light from the yellow light by a light projection unit, and a laser light source. It is a figure which illustrates the spectral sensitivity characteristic of the image sensor provided in the visible camera. It is a flowchart explaining the flow of the process which a control part performs. It is a figure which illustrates the spectral characteristic about each color light from the yellow light by the light projection unit of the modification 1, and an LED light source. FIG. 11 is a main part configuration diagram of an optical system of a projector in Modification 5. It is a figure which illustrates the state in which a yellow transmissive filter is located on an optical path.

  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 25, a visible camera 11, a yellow transmission filter 12, a filter driving member 13, a light projecting unit 14, and a reflection mirror 30.

  The projection unit 20 includes a laser light source, a reflective display element, and a projection optical system. The laser light source includes, for example, a semiconductor laser (hereinafter referred to as LD) that emits green light, an LD that emits red light, and an LD that emits blue light, and constitutes a three-primary-color light source. The laser light source illuminates the reflective display element in color sequence by emitting each color in time division.

  The reflective display element is constituted 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 source in the color sequence, a full color image is projected using one reflective display element. The projection light beam emitted from the projection unit 20 via the projection optical system is bent by the reflection mirror 30. Thereby, a full color image is projected on the projection area which is an installation surface.

  The image signal projected by the projection unit 20 is supplied to the projector 1 from an external device. The control unit 25 controls the projection unit 20 by driving the reflective display element based on the image signal from the external device and causing the laser light source 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 25 performs drive control on the visible camera 11, the filter drive member 13, and the light projecting unit 14 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 25 acquires an image captured by the visible camera 11 and corrects an image to be displayed on the reflective display element so as to eliminate the trapezoidal distortion when the image has a trapezoidal distortion. Thereby, trapezoidal distortion correction is performed on the image projected from the projection unit 20. In addition, the control unit 25 acquires an image captured by the visible camera 11, and when color correction of the image is necessary, the color of the projected image is adjusted by individually adjusting the density of the color component that is excessive or insufficient. Make corrections. 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 14 is configured by an LED that emits yellow light, for example. The light projecting unit 14 emits a light beam parallel to the installation surface in response to an instruction from the control unit 25. Since yellow light from the light projecting unit 14 does not irradiate the installation surface, the yellow light does not affect the projection image by the projection unit 20. The yellow transmission filter 12 transmits yellow light among wavelengths in the visible light region and blocks other visible light wavelengths other than yellow light. The filter drive member 13 drives the yellow transmission filter 12 forward and backward on the optical path of the imaging light flux of the visible camera 11 in accordance with an instruction from the control unit 25. When the yellow transmission filter 12 is located on the optical path, the visible camera 11 can capture a monochromatic image with yellow light. When the yellow transmission filter 12 is located outside the optical path, the visible camera 11 can capture a full color image.

  FIG. 1 illustrates a state in which the yellow transmission filter 12 is located outside the optical path. On the other hand, FIG. 2 illustrates a state in which the yellow transmission filter 12 is located on the optical path. In FIG. 2, the user touches a predetermined area indicated by the full-color image with a finger or the like. The fingertip blocks the light flux from the light projecting unit 14, and the yellow light is diffusely reflected by the fingertip. A part of the reflected light of yellow light travels toward the visible camera 11.

  FIG. 3 is a diagram illustrating the spectral characteristics of yellow light by the light projecting unit 14 and each color light from the laser light source described above. In FIG. 3, the horizontal axis represents the emission wavelength (unit: nm), and the vertical axis represents the emission intensity. The scale of the vertical axis is shown as a relative value where the maximum value of the emission intensity is 1. Yellow light indicated by a broken line 31 is distributed in the vicinity of 580 nm, which is an intermediate color between green and red. That is, it is a wavelength different from the three wavelengths of the RGB components by the laser light source. A solid line 32 including a broken line 31 represents the spectral characteristics of the yellow transmission filter 12. The yellow transmission filter 12 includes a wavelength region of light emitted from the light projecting unit 14 in a transmission region, and includes a wavelength region of each color emitted from a laser light source in a blocking region.

  FIG. 4 is a diagram illustrating spectral sensitivity characteristics of an image sensor (not shown) provided in the visible camera 11. This spectral sensitivity characteristic is a combination of the wavelength sensitivity characteristic of the photodiode constituting the imaging device, the cutoff characteristic by the color filter arranged on the photodiode, and the infrared light cutoff filter. In FIG. 4, the horizontal axis represents the light reception wavelength (unit: nm), and the vertical axis represents the light reception sensitivity. The scale of the vertical axis is shown as a relative value with a maximum light receiving sensitivity of 1. Among the waveforms corresponding to the three “mountains” in FIG. 4, the waveform near the wavelength of 450 nm corresponds to the sensitivity characteristic of the received blue light, and the waveform near the wavelength of 550 nm corresponds to the sensitivity characteristic of the received green light. The waveform near the wavelength of 610 nm corresponds to the sensitivity characteristic of the received red light.

  According to FIG. 4, the yellow light (wavelength near 580 nm) can be received as red light and also as green light by the imaging device. That is, the visible camera 11 can take an image of the yellow light component by the light projecting unit 14. For this reason, the yellow image containing the yellow light reflected with the finger | toe can be acquired by making the visible camera 11 image | photograph in the state of FIG. The control unit 25 detects a position coordinate (a pixel position having the highest luminance in the screen) where yellow light is reflected in the yellow image, and performs a predetermined process based on the detected position.

  As an example of the predetermined processing, for example, when the detection position is included in the left region of the shooting screen (yellow image), the image projected by the projection unit 20 is returned to the previous frame. On the other hand, when the detection position is included in the right area of the shooting screen (yellow image), 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 25. When the power on operation of the projector 1 is performed, the control unit 25 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 step S1 of FIG. 5, the control unit 25 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. Note that the initial position of the yellow transmission filter 12 is outside the optical path of the luminous flux of the visible camera 11. That is, in the first imaging mode, the visible camera 11 can capture a full color image (FIG. 1).

  In step S2, the control unit 25 acquires the projection state. Specifically, an instruction is sent to the visible camera 11, an initial image projected by the projection unit 20 is taken, and the process proceeds to step S3. In step S3, the control unit 25 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 25 makes a positive determination in step S3 and proceeds to step S4. If the result of the check is negative, the control unit 25 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 25 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 25 switches from the first imaging mode to the second imaging mode and proceeds to step S5. Specifically, an instruction is sent to the filter driving member 13 to move the yellow transmission filter 12 onto the optical path of the photographing light flux of the visible camera 11. Thereby, the projector 1 shifts to the normal operation (FIG. 2).

  In normal operation, while projecting an image from the projection unit 20, a yellow image is acquired by the visible camera 11 every predetermined time (for example, 30 frames / second). The control unit 25 checks whether there is a change between frames of the yellow image, and detects the touch position based on the yellow image as described above when the change is detected.

  In step S5, the control unit 25 sends an instruction to the light projecting unit 14 to emit yellow light. The control unit 25 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 25 may be projected.

  When the user touches the projection area with a finger or the like, the control unit 25 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 25 proceeds to step S7. In step S7, the control unit 25 sends an instruction to the projection unit 20, ends the image projection, and proceeds to step S8. In step S8, the control unit 25 switches from the second imaging mode to the first imaging mode, and ends the process of FIG. Specifically, an instruction is sent to the filter driving member 13 to retract the yellow transmission filter 12 out of the optical path of the photographing light flux of the visible camera 11. As a result, the process is terminated after moving to the initial position in preparation for the next activation.

According to the embodiment described above, the following operational effects can be obtained.
(1) The projector 1 uses a laser light source 20 that emits red, green, and blue light, a reflective display element 20 that modulates illumination light from the laser light source 20, and a modulated light from the reflective display element 20. A projection optical system 20 that projects an image, a light projecting unit 14 that emits yellow light different from red, green, and blue in substantially parallel to the projection surface of the projection optical system 20, and an image corresponding to yellow A visible camera 11 that acquires a yellow image including a projection area by the optical system 20, a control unit 25 that detects a change between images based on a yellow image that the visible camera 11 acquires at predetermined intervals, and a detection position in the yellow image. And a control unit 25 for instructing a predetermined process based on the touch position. Therefore, the touch position can be detected so that the user himself can understand the detected touch position.

(2) In the projector 1, a yellow transmission filter 12 that transmits a wavelength range including yellow and blocks a wavelength range including red, green, and blue, and on the optical path of subject light that travels to the visible camera 11 and outside the optical path The filter drive member 13 that moves the yellow transmission filter 12 between the filter drive member 13 and the filter drive member 13 and the visible camera 11 so that the visible camera 11 acquires a yellow image with the yellow transmission filter 12 positioned on the optical path. The control unit 25 is further provided, so that an imaging unit for a general digital camera can be used as the visible camera 11, and a yellow image can be appropriately acquired.

(3) In the above (2), the control unit 25 further includes an image corresponding to red, green, and blue, and the filter driving member 13 so as to acquire a full-color image including a projection area by the projection optical system 20 and Since the control part 25 which controls the visible camera 11 and correct | amends the image projected from the projection optical system 20 based on a full color image is further provided, the visible camera 11 is used for a projection image correction besides a touch position detection. be able to.

(4) In the above (3), the control unit 25 controls the filter driving member 13 and the visible camera 11 so that the visible camera 11 acquires a full color image with the yellow transmission filter 12 positioned outside the optical path. Since it is configured, a full color image can be acquired appropriately.

(5) In the above (3) or (4), the control unit 25 further controls the light projecting unit 14 so as to stop the yellow light emission when the visible camera 11 acquires a yellow image. A full color image can be acquired appropriately.

(Modification 1)
As a light source of the projection unit 20, an LED light source may be used instead of the laser light source. FIG. 6 is a diagram illustrating spectral characteristics of yellow light by the light projecting unit 14 and light of each color from the LED light source in the case of the first modification. In FIG. 6, the horizontal axis represents the emission wavelength (unit: nm), and the vertical axis represents the emission intensity. The scale of the vertical axis is shown as a relative value where the maximum value of the emission intensity is 1. Also in the first modification, the yellow light indicated by the broken line 31 is distributed in the vicinity of 580 nm, which is an intermediate color between green and red. A solid line 32 including a broken line 31 represents the spectral characteristics of the yellow transmission filter.

(Modification 2)
For the light emitted from the light projecting unit 14 for detecting the touch position of the projection area, magenta light or cyan light may be used instead of yellow light. Magenta light is a color when red and blue are present. The magenta light can be received as red light and also as blue light by the imaging device. That is, the visible camera 11 can take an image based on the magenta light component by the light projecting unit 14. Therefore, a magenta image including a part of the magenta light reflected by the finger can be acquired by causing the visible camera 11 to perform photographing in the state of FIG. The control unit 25 detects a position coordinate (a pixel position having the highest luminance in the screen) where the magenta light is reflected in the magenta image, and performs a predetermined process based on the detected position.

  On the other hand, cyan light is a color when blue and green exist. The cyan light can be received as green light and also as blue light by the imaging device. That is, the visible camera 11 can take an image of cyan light components by the light projecting unit 14. Therefore, a cyan image including a part of cyan light reflected by the finger can be acquired by causing the visible camera 11 to perform photographing in the state of FIG. The control unit 25 detects a position coordinate (a pixel position having the highest luminance in the screen) where cyan light is reflected in the cyan image, and performs a predetermined process based on the detected position.

(Modification 3)
In the above description, the example in which the light projecting unit 14 continuously emits light has been described. However, instead of continuous light emission, blinking light may be emitted. 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 14 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 14 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 supply 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 14 may be caused to blink. 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 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 in the fifth modification. FIG. 7 illustrates a state where the yellow transmission filter 12 is located outside the optical path of the imaging light flux of the visible camera 11, and FIG. 8 illustrates a state where the yellow transmission filter 12 is located on the optical path.

  7 and 8, the same reference numerals are used for members common to those in FIGS. In the modified example 5, since the visible camera 11 is farther from the installation surface than in the case of FIGS. 1 and 2, 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 ... Yellow transmission filter 13 ... Filter drive member 14 ... Projection unit 20 ... Projection unit 25 ... Control part 30 ... Reflection mirror

Claims (8)

A first light source that emits light of a first visible wavelength;
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;
A second light source that emits light having a second visible wavelength different from the first visible wavelength substantially parallel to a projection surface of the projection optical system;
An imaging unit that acquires a first image that corresponds to the second visible wavelength 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,
A filter that transmits a wavelength range including the second visible wavelength and blocks a wavelength range including the first visible wavelength;
Filter moving means for moving the filter between an optical path of subject light traveling to the imaging means and outside the optical path;
Control means for controlling the filter moving means and the imaging means so that the imaging means acquires the first image in a state where the filter is located on the optical path;
An electronic device characterized by further comprising: The electronic device according to claim 2,
The control means further controls the filter moving means and the imaging means so as to obtain a second image that is an image corresponding to the first visible wavelength and includes a projection region by the projection optical system,
An electronic apparatus, further comprising a correcting unit that corrects an image projected from the projection optical system based on the second image. The electronic device according to claim 3,
The electronic device is characterized in that the control means controls the filter moving means and the imaging means so that the imaging means acquires the second image in a state where the filter is located outside the optical path. The electronic device according to claim 3 or 4,
The electronic device is further characterized in that the control means controls the second light source so as to stop the emission of the second visible wavelength when the imaging means acquires the first image. In the electronic device of Claims 2-5,
The electronic device is characterized in that the control means further changes the light emission mode of the second visible wavelength according to at least one of a remaining battery level and a temperature in the device. In the electronic device as described in any one of Claims 1-6,
The electronic device according to claim 1, wherein the first visible wavelength includes wavelengths corresponding to red, green, and blue. In the electronic device as described in any one of Claims 1-7,
The electronic device according to claim 1, wherein the second visible wavelength includes wavelengths corresponding to yellow, magenta, and cyan.

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