JP5298425B2 - Projector and camera - Google Patents

Description

  The present invention relates to a projection apparatus and a camera.

  A technique for darkening a projected image when an object is detected during projection by a projection display device is known (see Patent Document 1).

JP 2000-19637 A

  In the prior art, there is a problem that a reaction occurs even when an object other than a person enters the projection region.

(1) According to a first aspect of the present invention, there is provided a projection apparatus that projects an optical image by illuminating an element that forms an image with a light emitting unit, an imaging unit that captures a subject image, and outputs an image signal. An image output by the imaging unit by causing the imaging unit to capture at least a part of the optical image or a region including the vicinity of the optical image during projection by the projection unit; Control means for controlling the face detection means so as to detect a face from a signal, and controlling the luminance of the optical image using a detection result by the face detection means, wherein the control means comprises the face detection means After performing face detection, if a luminance change occurs in an image signal corresponding to the outside of the projection image by the projection unit in the image signal output from the imaging unit, the face detection means Characterized in that to execute the degrees face detection.
(2) The projection apparatus according to the invention described in claim 2 is the projection apparatus according to claim 1 , wherein the control means is a luminance of the optical image according to a face position in the image detected by the face detection means. It is characterized by controlling.
(3) The projection apparatus according to the invention described in claim 3 is the projection apparatus according to claim 2 , wherein the control unit is configured to detect the optical image when the face position corresponds to a projection range of the projection unit. It is characterized in that the luminance is lower than the normal luminance.
(4) According to a fourth aspect of the present invention, there is provided a projection apparatus according to the first aspect , further comprising distance measuring means for acquiring distance information to a subject, wherein the control means includes the face detecting means. The brightness of the optical image is controlled in accordance with the distance information acquired for the detected face.
(5) In the projection device according to the invention described in claim 5, in the projection device according to claim 4 , the control means sets the luminance of the optical image to be higher than the normal luminance when the distance information indicates a predetermined distance or less. It is characterized by lowering.
(6) According to a sixth aspect of the present invention, there is provided a projection apparatus according to the first aspect , further comprising distance measuring means for acquiring distance information to a subject, wherein the control means includes the face detecting means. The brightness of the optical image is controlled in accordance with the face position in the detected image and the distance information acquired for the face detected by the face detection means.
(7) The projection apparatus according to the invention described in claim 7 is the projection apparatus according to claim 6 , wherein the control means corresponds to the face position corresponding to a projection range by the projection unit, and the distance information is predetermined. When the distance is equal to or smaller than the distance, the brightness of the optical image is lowered from the normal brightness.
(8) In the projection device according to any one of claims 4 to 7 , the control device according to the invention described in claim 8 is the projection device according to any one of claims 4 to 7 , wherein the distance information cannot be acquired by the distance measurement device. The projection of the optical image is stopped.
(9) In the projection device according to the invention described in claim 9, in the projection device according to claim 1 , the control unit is configured to detect each face from an image projected by the projection unit and an image signal output by the imaging unit. Controlling the face detection means to detect,
The face detection means controls the brightness of the optical image according to whether or not a face not detected from the projected image is detected from the image signal.
(10) The projection apparatus according to the invention described in claim 10 is the projection apparatus according to claim 9 , wherein the control means detects the face that the face detection means has not detected from the projected image as the image signal. When detected from the above, the brightness of the optical image is lowered from the normal brightness.
(11) The projection device according to the invention described in claim 11 is characterized in that, in the projection device according to claim 9 or 10 , the opening of the projection unit and the opening of the imaging unit are arranged vertically. .
(12) The projection apparatus according to the invention of claim 12 is the projection apparatus according to claim 1, wherein when the predetermined time elapses after the face detection means performs the face detection, the control means The detection unit is caused to perform face detection again.
(13) The projection device according to the invention described in claim 13 is the projection device according to any one of claims 1 to 12 , wherein the control means includes the face detection means out of images formed on the element. The projection unit is further controlled so that the brightness of the optical image in the region corresponding to the detected face is lowered.
(14) A camera according to a fourteenth aspect of the present invention includes the projection device according to any one of the first to thirteenth aspects.

  According to the present invention, it is possible to control the light emission luminance in response to only a person.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a front view of an electronic camera with a projector (hereinafter referred to as a PJ built-in electronic camera) according to an embodiment of the present invention. In FIG. 1, an imaging optical system 121, a projection optical system 221 and an illumination light window 106A are provided in front of the PJ built-in electronic camera. The PJ built-in electronic camera is mounted on a desk or the like, or is mounted on a cradle (not shown), and is built in toward the screen in front of the PJ built-in electronic camera. To project projection information such as an image. A release button 103A is provided on the upper surface of the electronic camera with a built-in PJ. An imaging optical system 121 of a camera unit 100 (FIG. 2) described later and a projection optical system 221 of the projection unit 200 are arranged side by side in the vertical direction.

  FIG. 2 is a block diagram illustrating the configuration of the PJ built-in electronic camera. In FIG. 2, the PJ built-in electronic camera includes a projection unit 200, a camera unit 100, a CPU 101, a memory 102, an operation member 103, a liquid crystal monitor 105, an external interface (I / F) circuit 104, and an illumination device 106. And a removable memory card 150 is mounted.

  Based on the control program, the CPU 101 performs a predetermined calculation using a signal input from each part in the camera and sends a control signal to each part in the camera, so that the photographing operation and projection of the PJ built-in electronic camera are performed. Control each action. The control program is stored in a nonvolatile memory (not shown) in the CPU 101.

  The memory 102 is used as a working memory for the CPU 101. The operation member 103 includes a release button 103A, and sends an operation signal corresponding to the operated button or switch to the CPU 101. The memory card 150 is configured by a nonvolatile memory, and data can be written, stored, and read according to instructions from the CPU 101.

  The liquid crystal monitor 105 displays information such as images and texts according to instructions from the CPU 101. The text information is an operation menu, a message, and the like of the PJ built-in electronic camera. The external interface circuit 104 transmits / receives commands and data to / from an external device (personal computer, cradle, etc.) via a cable (not shown) or a wireless communication unit according to an instruction from the CPU 101.

  The camera unit 100 includes an image pickup optical system 121, an image pickup element 122, and an image pickup control circuit 123, and performs shooting according to an instruction from the CPU 101. The imaging optical system 121 forms a subject image on the imaging surface of the imaging element 122. As the image sensor 122, a CCD, a CMOS image sensor, or the like is used. The imaging control circuit 123 controls driving of the imaging element 122 according to an instruction from the CPU 101 and performs predetermined signal processing on an image signal output from the imaging element 122. The image data after the signal processing is recorded in the memory card 150 as an image file in a predetermined format.

  The illumination device 106 flashes with a predetermined light amount to illuminate the subject when a light emission instruction is issued from the CPU 101 during shooting. The illumination light is emitted forward of the camera through the illumination light window 106A.

  The projection unit 200 includes a projection optical system 221, a liquid crystal panel 222, an LED light source 223, and a projection control circuit 224. The LED light source 223 illuminates the liquid crystal panel 222 with brightness according to the supply current. The liquid crystal panel 222 generates a light image according to the drive signal from the projection control circuit 224. The projection optical system 221 projects a light image emitted from the liquid crystal panel 222. The projection control circuit 224 sends a control signal to the LED light source 223 and the liquid crystal panel 222 according to an instruction from the CPU 101.

  The projection unit 200 is configured to be able to project a reproduction image based on image data supplied from an external device via the external interface circuit 104 in addition to image data stored in the memory card 150, and an image instructed by the CPU 101. Project.

  The electronic camera with a built-in PJ has a shooting mode for shooting with the camera unit 100 and a projection mode for projecting information from the projection unit 200. Since the present embodiment is characterized by an operation when the “safe mode” is instructed in the projection mode, this operation will be mainly described. The “safe mode” is a mode in which light source luminance is suppressed when a “face” such as a presenter is detected in the projection range.

<Face detection>
The electronic camera with a built-in PJ is configured to execute a “face detection” process in order to determine a focus area that is a target of autofocus adjustment in the shooting mode. Face detection is to extract an image area corresponding to a human face from a shooting preparation image (so-called through image) at the time of shooting. The through image is an image that is sequentially picked up by the image sensor 122 before being instructed to be photographed and reproduced and displayed on the liquid crystal monitor 105.

  The CPU 101 extracts a face area from the through image as follows. As an extraction method, as disclosed in JP-A-9-138470, there are a plurality of methods such as a method of extracting a specific color, a method of extracting a specific shape pattern, a method of removing a region estimated to correspond to the background, and the like. Evaluate different extraction methods in advance to determine the weight, extract the main subject image (main part) with each extraction method, weight the extracted main part with the determined weight, and determine the main part according to the result And extract.

  As another main part extraction method, as disclosed in Japanese Patent Laid-Open No. 9-138471, the density or luminance of a plurality of points in an image is measured to determine the amount of change, and the amount of change is equal to or greater than a predetermined value. After setting the point as a reference point, a search range and a search direction pattern are set using a change amount of density and the like within a predetermined range from the reference point, and the density and the like in the direction indicated by the search direction pattern within the search range are set. A part where the amount of change is equal to or greater than a predetermined value is searched, and then the search is repeated using this part as a reference, and the main part is extracted by connecting the searched and set reference points.

  The CPU 101 extracts a face area from the through image displayed on the liquid crystal monitor 105 and causes the liquid crystal monitor 105 to display the extracted face area. FIG. 3 is a diagram illustrating a display screen of the liquid crystal monitor 105 in this case. In FIG. 3, the face 30 is recognized, and a frame 31 indicating the recognized face (the extracted face) is overlaid on the through image.

  The CPU 101 focuses on the recognized face by performing focus adjustment using image data corresponding to the frame 31 indicating the face recognized in this way. When a plurality of faces are recognized, for example, focusing on the face closest to the camera is performed. The position (focus position) after focusing of the focus lens constituting the imaging optical system 121 differs depending on the distance from the camera to the subject (face).

  The electronic camera with a built-in PJ according to this embodiment performs a safety mode operation for controlling the light emission amount of the LED light source 223 by performing the face recognition even in the projection mode.

  4 and 5 are flowcharts for explaining the flow of the light amount control processing executed by the CPU 101 in the safety mode. When an on operation signal is input from a safety switch (not shown) that constitutes the operation member 103 in the projection mode, the CPU 101 activates the process illustrated in FIG. 4 and 5 are repeatedly performed until an OFF operation signal is input from a safety switch (not shown).

  In step S1 of FIG. 4, the CPU 101 determines whether or not the lens position is WIDE. The CPU 101 makes an affirmative decision in step S1 when the position of the zoom lens constituting the imaging optical system 121 is on the WIDE side from the predetermined position, proceeds to step S3, and negates step S1 if it is on the TELE side from the predetermined position. Determine and proceed to step S2.

  In step S2, the CPU 101 sends an instruction to the imaging control circuit 123, moves the zoom lens to a predetermined WIDE position, and proceeds to step S3. As a result, the camera angle of view of the electronic camera with built-in PJ is controlled so that the camera unit 100 captures a range wider than the projection range projected by the projection unit 200.

  In step S3, the CPU 101 sends an instruction to the projection control circuit 224, turns on the LED light source 223 with low luminance, and proceeds to step S4. The low luminance is a state in which the light emission amount is reduced to, for example, half the luminance as compared with the normal lighting luminance (high luminance lighting) by the LED light source 223. Thereby, a reproduction image of the designated projection source (for example, an image file recorded in the memory card 150) is projected from the projection unit 200 onto the screen (not shown) with low luminance.

  In step S4, the CPU 101 determines whether or not focusing on the projection surface (screen) is possible. FIG. 6 is a diagram illustrating a shooting screen shot by the camera unit 100. In FIG. 6, the PJ built-in electronic camera captures an imaging range 60 wider than the projection range 61. Since the projection unit 200 performs projection with low luminance, a region outside the projection range 62 exists in a frame shape outside the projection range 61 in the imaging range 60. Since the projection range 61 is imaged brighter than the region outside the projection range 62, the CPU 101 can detect contrast between the projection range 61 and the region outside the projection range 62.

  The CPU 101 makes a positive determination in step S4 when the contrast is detected from the image acquired by the camera unit 100 and proceeds to step S5. If the contrast cannot be detected from the image acquired by the camera unit 100, the CPU 101 performs the determination process. repeat.

  When the process proceeds to step S5, the CPU 101 performs focus adjustment by a contrast method on the screen. Specifically, a known focus evaluation value calculation is performed based on the imaging signal output from the imaging element 122 while moving the focus lens of the imaging optical system 121 forward and backward in the optical axis direction, thereby obtaining a high-frequency component of the image. A focus evaluation value (referred to as contrast information) replaced with sharpness is calculated. Since the contrast information is maximized when the imaging optical system 121 is focused on a sharp image on the image sensor 122, the focus lens is moved to a position where the contrast information is maximized.

  In step S5, the CPU 101 records data indicating the in-focus position (focus lens position after in-focus) in a predetermined area of the memory 102, and proceeds to step S6. In step S6, the CPU 101 determines whether there is face recognition data. When data indicating a face area is recorded in the image file being projected, the CPU 101 reads the data, makes an affirmative decision in step S6, and proceeds to step S13 in FIG. If the data indicating the face area is not recorded in the image file being projected, the CPU 101 makes a negative determination in step S6 and proceeds to step S7.

  In step S7, the CPU 101 starts face recognition processing for the image data being projected, and proceeds to step S8. In step S8, the CPU 101 extracts feature points necessary for face recognition, and proceeds to step S9. In step S9, the CPU 101 determines whether face recognition is possible. If the face can be recognized, the CPU 101 makes a positive determination in step S9 and proceeds to step S10. If the face cannot be recognized, the CPU 101 makes a negative determination in step S9 and proceeds to step S13 in FIG.

  In step S10, the CPU 101 records the data indicating the recognized face position and area (size) in the image file being projected, and proceeds to step S13 in FIG. The recorded data represents, for example, the coordinates and range of data corresponding to the frame 31 indicating the face in the image data developed in the memory 102.

  In step S11 that proceeds when step S22 in FIG. 5 is affirmatively determined or when step S25 is affirmatively determined, the CPU 101 determines whether or not the projected images are the same. If the CPU 101 is projecting the same image as when the previous face recognition was performed, the CPU 101 makes a positive determination in step S11 and proceeds to step S13 in FIG. If the same image is not projected, the CPU 101 makes a negative determination in step S11 and returns to step S4.

  In the determination process of step S11, when a still image is projected or a slide show is projected, the process proceeds to step S13 if an image of the same frame as that at the time of face recognition is projected. On the other hand, if a still image or a slide show is being projected, an image of a frame different from the point at which face recognition was performed is projected, and if a moving image is being projected, the process returns to step S4. When returning to step S4, face recognition processing is performed again on the image being projected, and when proceeding to step S13, face recognition processing is performed on the through image.

  In step S13 of FIG. 5, the CPU 101 starts face recognition processing on the photographic data (through image obtained by capturing the projected image being projected), and proceeds to step S14. In step S14, the CPU 101 extracts feature points necessary for face recognition, and proceeds to step S15. In step S15, the CPU 101 determines whether face recognition is possible. If the face can be recognized, the CPU 101 makes a positive determination in step S15 and proceeds to step S16. If the face cannot be recognized, the CPU 101 makes a negative determination in step S15 and proceeds to step S21.

  In step S16, the CPU 101 compares and determines the projection data and the shooting data (through image), and proceeds to step S17. The comparison determination is performed on the face positions and areas recognized in both images. In step S <b> 17, the CPU 101 determines whether a face that has not been recognized from the projection data has been recognized from the shooting data. If a face that does not correspond to the data recorded in step S10 is recognized from the through image, the CPU 101 makes a positive determination in step S17 and proceeds to step S18. On the other hand, if only the face corresponding to the data recorded in step S10 is recognized from the through image, the CPU 101 makes a negative determination in step S17 and proceeds to step S21.

  In the through image illustrated in FIG. 6, the face 30 </ b> A is recognized. A frame 31A indicating the recognized face corresponds to the face frame 31 (FIG. 3) recognized in the projection data. If no other face is recognized in the through image, the CPU 101 makes a negative determination in step S17.

  In step S18, the CPU 101 performs focus adjustment on the foremost face (close to the electronic camera with a built-in PJ), and proceeds to step S19. Specifically, contrast information is calculated based on the imaging signal corresponding to the face area, and the focus lens is moved to a position that maximizes the contrast.

  In step S19, the CPU 101 determines whether or not the in-focus position with respect to the foremost face is the same as the in-focus position with respect to the projection plane (screen). When the in-focus position recorded in a predetermined area of the memory 102 matches the in-focus position with respect to the foremost face (the distance to the foremost face is the same as the distance to the screen) Makes an affirmative decision in step S19 and proceeds to step S21. If not matched (the distance to the foremost face is shorter than the distance to the screen), a negative determination is made in step S19 and the process proceeds to step S20.

  In step S20, the CPU 101 sends an instruction to the projection control circuit 224, turns on the LED light source 223 with low luminance, and proceeds to step S22. Note that when the light is already lit at a low luminance, the low luminance state is maintained.

  In step S21, the CPU 101 sends an instruction to the projection control circuit 224, turns on the LED light source 223 with high luminance, and proceeds to step S22. High luminance means a state in which the lighting luminance of the LED light source 223 is increased to twice the normal luminance (normal luminance).

  In step S22, the CPU 101 determines whether there is a luminance change outside the projection range. When the signal value of the pixel signal corresponding to the out-of-projection range region 62 illustrated in FIG. 6 has changed by a predetermined value or more, the CPU 101 makes a positive determination in step S22 and proceeds to step S11 in FIG. If the change in the signal value of the pixel signal corresponding to the out-of-projection area 62 is less than the predetermined value, the CPU 101 makes a negative determination in step S22 and proceeds to step S23.

  In step S23, the CPU 101 waits for 1 second and proceeds to step S24. In step S24, the CPU 101 adds 1 to the counter and proceeds to step S25. In step S25, the CPU 101 determines whether or not the count value = 10. If the value of the counter is 10, the CPU 101 makes a positive determination in step S25 and proceeds to step S11 in FIG. If the count value is not 10, the CPU 101 makes a negative determination in step S25 and returns to step S22.

  According to the embodiment described above, the following effects can be obtained.

(1) The PJ built-in electronic camera acquires a through image from the projection unit 200 by the camera unit 100 during projection. Furthermore, since the face recognition is performed on the through image and the brightness of the light source unit of the projection unit 200 is controlled using the face recognition result, the brightness of the projection light can be changed only when the face is recognized from the through image. .

(2) Since the electronic camera with a built-in PJ controls the brightness of the light source unit of the projection unit 200 according to the position of the face recognized in the through image, only when the face is recognized within a predetermined area of the through image, The brightness can be changed.
(3) When the face is recognized in the region corresponding to the projection range by the projection unit 200, the brightness of the projection light is lowered from the normal brightness, so that the anti-glare operation can be performed on the face located in the projection range. .

(4) Since the PJ built-in electronic camera controls the brightness of the light source unit of the projection unit 200 according to the distance information to the recognized face in the through image, when the face is recognized within a predetermined distance from the PJ built-in electronic camera. Only the brightness of the projection light can be changed.
(5) When the distance to the foremost face is shorter than the distance to the screen, that is, when the face recognized face is within a predetermined distance from the electronic camera with built-in PJ, the brightness of the projected light is lowered from the normal brightness. An anti-glare operation can be performed on a face at a distance.

(6) Since the PJ built-in electronic camera controls the brightness of the light source unit of the projection unit 200 according to the position of the face recognized in the through image and the distance information to the face, it is within a predetermined region of the through image, The brightness of the projection light can be changed only when the face is recognized within a predetermined distance from the PJ built-in electronic camera.
(7) When the face is recognized within a predetermined distance from the PJ built-in electronic camera within the area corresponding to the projection range by the projection unit 200, the brightness of the projection light is lowered from the normal brightness. An anti-glare operation can be performed on a face at a distance.

(8) The PJ built-in electronic camera acquires a through image with the camera unit 100 so as to include a projection image by the projection unit 200. Further, face recognition is performed on each of the image data projected by the projection unit 200 and the through image, and a light source unit of the projection unit 200 is determined depending on whether a face that is not recognized from the projected image data is recognized from the through image. To control the brightness. Thereby, the brightness of the projection light directed to the face different from the projected image can be changed, and the face included in the projected image is not subjected to the antiglare operation.
(9) When the face different from the projected image is recognized, the brightness of the projected light is lowered from the normal brightness, so that the anti-glare operation can be performed on the face different from the projected image.

(10) The opening of the projection optical system 221 of the projection unit 200 and the opening of the imaging optical system 121 of the camera unit 100 in the normal posture of the electronic camera with a built-in PJ are arranged vertically. As a result, a through image that is wider to the left and right than the projected image is obtained, and there is no horizontal displacement regardless of the distance, making it easier to recognize a face or brightness change different from the projected image on the left and right of the projected image.

(11) After performing the face recognition, the face recognition is performed again when the brightness change occurs outside the projection image in the through image. Therefore, when the object enters the projection range from the outside of the projection image. , Face recognition can be made again.
(12) Since the face recognition is performed again after a predetermined time has elapsed after performing the face recognition, the face can be recognized again when the luminance change cannot be detected.

(Modification 1)
In the above (10), the example in which the aperture of the projection optical system 221 and the aperture of the imaging optical system 121 are arranged vertically to suppress the influence of both parallaxes in the horizontal direction has been described. However, the vertical direction may be affected by parallax when the distance from the PJ built-in electronic camera to the projection surface (screen) is short. Specifically, the projection range 61 is not necessarily in the same position within the shooting range 60.

  FIG. 7 is a diagram for explaining the distance to the projection surface (screen) and the projection range 61 and the photographing range 60 at the distance. In FIG. 7, the optical axis of the projection optical system 221 and the optical axis of the imaging optical system 121 are parallel, and the distance between the optical axes is d. When screens are provided at position A (distance La from the electronic camera with built-in PJ), position B (distance Lb from the electronic camera with built-in PJ), and position C (distance Lc from the electronic camera with built-in PJ), respectively, The relative position between the projection range 61 and the shooting range 60 changes according to the distance. The projection range 61 and the photographing range 60 at the three distances La, Lb, and Lc have the same size and the ratio is changed as illustrated.

  According to FIG. 7, the shorter the distance between the PJ built-in electronic camera and the projection surface (screen), the greater the deviation between the center of the shooting range 60 and the center of the projection range 61. If the distance between the two in the vertical direction is y, the distance ya in the case of position A is ya = Y × d / (2 × La × tan θ). However, the height of the captured image is Y, and the captured field angle is (2 × θ). Similarly, the distance yb in the case of the position B is yb = Y × d / (2 × Lb × tan θ), and the distance yc in the case of the position C is yc = Y × d / (2 × Lc × tan θ). It is.

  The distance d is known from the design information of the camera body, and the angle θ is known from the design information of the imaging optical system 121 (if the imaging optical system 121 is a zoom optical system, it may be converted from the zoom extension amount). Therefore, if the distance L to the projection plane (screen) is obtained by the focusing operation, the position of the projection range 61 within the photographing range 60 can be predicted by causing the CPU 101 to calculate the above equation.

  As described above, even when there is an influence of parallax between the projection optical system 221 and the imaging optical system 121, the position of the projection range 61 can be predicted within the imaging range 60. By using such a prediction calculation when comparing projection data and captured data (through image) in step S16, the face portion to be compared can be quickly recognized from the through image.

(Modification 2)
The example in which the LED light source 223 is turned on with low brightness when the distance from the PJ built-in electronic camera to the foremost face is shorter than the distance from the PJ built-in electronic camera to the screen, that is, when negative determination is made in step S19 has been described. . Instead of turning on the LED light source 223 with low luminance, the LED light source 223 may be turned off.

(Modification 3)
Even when contrast information cannot be detected when focus adjustment is performed using the contrast method, a negative determination may be made in step S19. In this case, since the LED light source 223 is turned on with low brightness in a situation where the focus information cannot be adjusted without obtaining contrast information, the anti-glare operation is performed even when there is a possibility that a face is present in a space very close to the electronic camera with a built-in PJ. Can be done.

(Modification 4)
Instead of the third modification, the LED light source 223 may be turned off in a situation where the focus cannot be adjusted. By turning off the LED light source 223 when there is a possibility that a face exists in a space very close to the electronic camera with a built-in PJ, a safer projection apparatus can be obtained.

(Modification 5)
You may comprise so that the projection light which goes to the area | region containing the recognized face may be selectively attenuated. In this case, the CPU 101 performs partial projection light emitted by the projection unit 200 in the direction corresponding to the face area newly recognized from the through image in steps S13 to S15 (that is, the face not corresponding to the data recorded in step S10). Attenuate. Specifically, the CPU 101 sends an instruction to the projection control circuit 224, and the transmittance of the pixels in the corresponding region in the optical image generated by the liquid crystal panel 222 is suppressed (for example, ½) from the normal time. The pixel density is controlled to be increased. Thereby, the projection light projected from the projection unit 200 toward the newly recognized face is selectively reduced. When the image projected on the screen is white, the projected image may not be sufficiently dark even if the LED light source 223 is turned on with low luminance. If the projection image is partially darkened by performing the control of Modification 5 in such a scene, the light emitted toward the face can be partially weakened.

(Modification 6)
In the case where the LED light source 223 is turned on with low luminance, an example in which the LED light source 223 is reduced to ½ of normal luminance has been described. Instead of this, the lighting brightness of the LED light source 223 may be varied according to the distance information to the face recognized in the through image. The shorter the distance from the PJ built-in electronic camera to the face, the higher the emission luminance reduction rate (low emission luminance), and the longer the distance from the PJ built-in electronic camera to the face, the lower the emission luminance reduction rate (high emission luminance). ) The change in the light emission luminance during low-intensity lighting is proportional to the square of the distance.

(Modification 7)
When the LED light source 223 is turned on with low luminance, a warning LED may be provided to notify this. A power lamp (not shown) or an AF auxiliary light source may be used for the warning LED. In addition, an alarm message or mark may be displayed on the liquid crystal monitor 105, or an electronic sound may be generated from a speaker (not shown).

(Modification 8)
In the above description, the determination is made according to the position and area of the face recognized in the through image (steps S16 and S17), and the determination is made according to the distance information from the PJ built-in electronic camera to the recognized face (steps S18 and S19). In addition, an example is shown in which the determination (step 10, step S16, S17) performed in accordance with whether or not a face that is not recognized from the image data to be projected is recognized from the through image is combined. Instead of this, three determinations may be performed independently, or any two determinations may be combined.

(Modification 9)
In the above description, the focus adjustment method for performing contrast detection is illustrated as an example of acquiring distance information from the electronic camera with built-in PJ to the subject (face, screen, etc.). The focus adjustment method is not limited to the contrast detection method, and may be a phase difference detection method.

(Modification 10)
The arrangement of the projection optical system 221 of the projection unit 200 and the opening of the imaging optical system 121 of the camera unit 100 in the normal posture of the PJ built-in electronic camera may be arranged side by side. In this case, a through image that is wider above and below the projected image is obtained, and it becomes easier to detect a face and a brightness change that are different from the projected image above and below the projected image.

(Modification 11)
Although the case where the range captured by the camera unit 100 is wider than the range projected by the projection unit 200 has been described, the range captured by the camera unit 100 is an area including at least a part of the range of the projected image projected by the projection unit 200. It doesn't matter. In addition, the imaging range of the camera unit 100 does not include the projection image projected by the projection unit 200, and the vicinity of the projection image is captured, and it is determined whether there is a person in the imaging range and the brightness of the projection image is changed. Also good. This is because if there is a person in the vicinity of the projection image, this person may enter the projection area.

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

It is the figure which looked at the electronic camera with a built-in PJ according to an embodiment of the present invention from the front. It is a block diagram explaining the structure of a PJ built-in electronic camera. It is a figure which illustrates the display which shows the extracted face area. It is a flowchart explaining the flow of the light quantity control process which CPU performs. It is a flowchart explaining the flow of the light quantity control process which CPU performs. It is a figure which illustrates the imaging | photography screen image | photographed with a camera unit. It is a figure explaining the distance to a projection surface, and the projection range and imaging | photography range in the distance.

Explanation of symbols

100 ... Camera unit 101 ... CPU
DESCRIPTION OF SYMBOLS 103 ... Operation member 121 ... Shooting optical system 200 ... Projection unit 221 ... Projection optical system 222 ... Liquid crystal panel 223 ... LED light source 224 ... Projection control circuit

Claims (14)

A projection unit that projects an optical image by illuminating an element that forms an image with a light emitting unit;
An imaging unit that captures a subject image and outputs an image signal;
Face detection means for detecting a face from an image;
The face detection unit is configured to cause the imaging unit to capture an area including at least a part of the optical image or the vicinity of the optical image during projection by the projection unit, and to detect a face from an image signal output from the imaging unit. Control means for controlling the brightness of the optical image using the detection result by the face detection means,
When the brightness change occurs in the image signal corresponding to the outside of the projection image by the projection unit in the image signal output by the imaging unit after the face detection unit performs the face detection, the control unit detects the face Projecting apparatus that causes face detection to be executed again. The projection device according to claim 1 ,
The projection device characterized in that the control means controls the luminance of the optical image in accordance with the face position in the image detected by the face detection means. The projection apparatus according to claim 2 , wherein
The projection device according to claim 1, wherein the control means lowers the luminance of the optical image below the normal luminance when the face position corresponds to a projection range by the projection unit. The projection device according to claim 1 ,
It further comprises distance measuring means for acquiring distance information to the subject,
The projection apparatus, wherein the control unit controls the luminance of the optical image in accordance with the distance information acquired for the face detected by the face detection unit. The projection apparatus according to claim 4 , wherein
The control unit is characterized in that the brightness of the optical image is lowered from the normal brightness when the distance information indicates a predetermined distance or less. The projection device according to claim 1 ,
It further comprises distance measuring means for acquiring distance information to the subject,
The control means controls the brightness of the optical image according to the face position in the image detected by the face detection means and the distance information acquired for the face detected by the face detection means. apparatus. The projection apparatus according to claim 6 , wherein
The projection device according to claim 1, wherein the control means lowers the luminance of the optical image from a normal luminance when the face position corresponds to a projection range by the projection unit and the distance information indicates a predetermined distance or less. In the projection device according to any one of claims 4 to 7 ,
The control device stops projection of the optical image when distance information cannot be acquired by the distance measuring device. The projection device according to claim 1 ,
The control means controls the face detection means so as to detect each face from an image projected by the projection unit and an image signal output from the imaging unit, and the face detection means detects from the projected image. A projection apparatus, wherein brightness of the optical image is controlled in accordance with whether or not a face that has not been detected is detected from the image signal. The projection apparatus according to claim 9 , wherein
The projection device according to claim 1, wherein the control means lowers the brightness of the optical image from a normal brightness when the face detection means detects a face not detected from the projected image from the image signal. The projection device according to claim 9 or 10 , wherein:
A projection apparatus, wherein an opening of the projection unit and an opening of the imaging unit are arranged side by side vertically. The projection device according to claim 1,
The projection device, wherein the control unit causes the face detection unit to perform face detection again when a predetermined time has elapsed since the face detection unit performed face detection. In the projection device according to any one of claims 1 to 12 ,
The control means further controls the projection unit so that the luminance of the optical image in a region corresponding to the face detected by the face detection means among images formed on the element is lowered. apparatus. A camera comprising the projection device according to claim 1 .

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