JP3396179B2 - camera - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera having a line-of-sight detection device which projects a light beam on an eyeball of an observer and detects the direction of the line of sight by using a Purkinje image obtained from the reflected light.

[0002]

2. Description of the Related Art Conventionally, when inputting information to a camera, the information necessary for distance measurement and photometry has been input by an input operation member such as a dial and a button. Is easy to get complicated. Therefore, a technique for inputting information to the camera according to the line of sight of the photographer has been developed.

For example, Japanese Patent Application Laid-Open No. 2-5 discloses a technique relating to a visual axis detecting device for detecting the visual axis direction of an observer based on the first Purkinje image. When this line-of-sight detection device is applied to a photographing device such as a camera, the line-of-sight detection is always performed when the photographer is looking through the viewfinder. Further, the position of the gazing point detected by the line-of-sight is superposed on the finder screen, and the line-of-sight information when a specific switch is operated is fetched to give various instructions to the apparatus main body.

However, the movement of the line of sight of the photographer does not always look only at the main subject at the time of photographing. Therefore, for example, a camera has been proposed in which an autofocus area can be selected from arbitrary areas according to the movement of the line of sight, and reliable and reliable operation has become possible.

However, the movement of the photographer's line of sight does not necessarily mean that he or she is gazing at the main subject during photographing.
According to the Institute of Electronics, Information and Communication Engineers Technical Report PRU88-73 "Method of extracting feature points for non-contact gaze detection" (Bano et al.), The human gaze time is usually about 200 to 350 ms. In consideration of averaging the fixed fine movements and accurately distinguishing from the jumping movements, it is desirable to perform the detection at intervals of about 60 ms in order to accurately follow the movement of the line of sight.

[0006]

However, when the visual axis detection is continuously performed, the detection interval is shortened and the detection is continued, so that the illumination light and the current consumption for driving the sensor become large.

For example, a device such as a camera is usually provided with a standby state, in which a display is displayed and waiting for input of various switches. At this time, when the photographer is not looking into the viewfinder, the detection is continued regardless of the necessity of the sight line detection, so that it can be said that there is unnecessary power consumption.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a camera having a visual axis detection device with a simple structure and reduced power consumption.

[0009]

In order to achieve the above object, in a first aspect of the present invention, a signal output means for outputting a signal according to a photographing preparation operation by a photographer, and a light for an eyeball of the photographer. And a photoelectric conversion unit that receives and photoelectrically converts the reflected light from the eyeball of the irradiation light, and a line-of-sight direction that detects the line-of-sight direction of the photographer based on a signal from the photoelectric conversion unit. When a signal for detecting the start of the shooting preparation operation is output by the signal line detecting means having a calculation portion and the signal output means, the observer's eyeball is attached to the eyepiece portion of the camera based on the signal from the photoelectric conversion portion. When the eyeball is not present by the discriminating means for discriminating whether or not the visual axis direction is calculated by the visual axis detecting means, regardless of the signal output state of the signal outputting means. Of gaze direction by The camera is provided which is characterized by comprising control means for controlling so as not to perform work, the. According to a second aspect of the present invention, there is provided a camera characterized in that the signal output means detects that an object approaches a viewfinder of the camera and outputs a signal. First above
According to the second aspect, the following actions are exhibited. That is, in the first aspect of the present invention, a signal is output by the signal output unit in accordance with a shooting preparation operation by the photographer, and in the line-of-sight detection unit, the detection light irradiation unit irradiates the eyeball of the photographer with light. The reflected light from the eyeball of the irradiation light is received by the photoelectric conversion unit and photoelectrically converted, and the line-of-sight direction calculation unit detects the line-of-sight direction of the photographer based on the signal from the photoelectric conversion unit. When the signal for detecting the start of the shooting preparation operation is output by the determination means by the signal output means,
It is determined whether or not the eyeball of the observer is present in the eyepiece of the camera based on the signal from the photoelectric conversion unit, and by the control unit, when it is determined that the eyeball is not present by the determination unit, Regardless of the signal output state of the signal output unit, the line-of-sight direction calculation operation of the line-of-sight detection unit is controlled so as not to be performed. In the second aspect of the present invention, the signal output means detects that an object approaches the viewfinder of the camera and outputs a signal.

[0010]

[0011]

[0012]

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing an outline of a line-of-sight detection device adopted by the present invention.

As shown in the figure, in the visual axis detection device of the present invention, a detection light irradiating section 1 for irradiating the eyeball of the photographer with light, and a reflected light of the irradiation light from the eyeball are received and photoelectrically converted. A photoelectric conversion unit 2 for conversion is provided.

The photoelectric conversion unit 2 is connected to a line-of-sight direction calculation unit 3 for detecting the line of sight, and the line-of-sight direction calculation unit 3 is connected to an eyepiece state detection unit 4.

Further, the eyepiece state detecting section 4 is connected to a detection mode switching section 5, and the detection mode switching section 5 is connected to a control section 6. The control unit 6 is connected to the detection light irradiation unit 1 and the line-of-sight direction calculation unit 3.

In such a configuration, the detection light irradiation section 1
When the eye illuminates the eyeball, the reflected light from the eyeball of the illuminating light is received by the photoelectric conversion unit 2 and photoelectrically converted. Then, the line-of-sight direction calculation unit 3 detects the line-of-sight direction of the photographer based on the signal from the photoelectric conversion unit 2.

On the other hand, when the eyepiece state detection unit 4 detects whether or not the photographer is looking into the viewfinder, the eyepiece state detection unit 4 sets the detection mode to the "line-of-sight detection mode" or "low" depending on the eyepiece state. Power consumption mode ".

The control unit 6 receives the signal from the detection mode switching unit 5 and controls the operations of the detection light irradiation unit 1 and the line-of-sight direction calculation unit 3 based on the signal.

As described above, in the visual axis detecting device of the present invention, the eyepiece state detecting section 4 is provided, and power consumption is reduced by selectively using the "visual axis detecting mode" and the "low power consumption mode" according to the detection result. It is characterized by making it smaller.

FIG. 2 is a diagram showing the structure of a camera having a visual axis detection device according to the first embodiment of the present invention.

As shown in the figure, in the observation optical system, a flip-up mirror 102 is arranged on the optical path of the light passing through the taking lens 101.
A liquid crystal plate 103, a focusing plate 104, and a condenser lens 105 are provided on the optical path of the reflected light of 2.

A penta roof prism 106 is provided on the optical path of the light passing through the condenser lens 105, and the reflecting surface 1 of the penta roof prism 106 is provided.
On the optical path of the light reflected by 06a, an eyepiece lens 11 which also serves as an optical member for detecting the line of sight is provided.
Further, an AF imaging lens 107 and an AF area sensor 108 are provided on the optical path of the light transmitted through the reflecting surface 106a of the penta roof prism.

On the other hand, the line-of-sight detection optical system is an infrared light emitting diode (LED) which is a light source insensitive to the photographer.
ing diode) 12 and a light projecting lens 13,
Line sensor 16, half mirror 17 and light receiving lens 1
5 and a light receiving section composed of 5 and arranged above an eyepiece lens 11 having a beam splitter 11a composed of a dichroic mirror.

In such a structure, the taking lens 10
The subject light that has passed through 1 is reflected by the flip-up mirror 102 and forms an image in the vicinity of the focal plane of the focusing plate 105 via the liquid crystal plate 103.

The subject image diffused by the focusing plate 105 is the condenser lens 106 and the penta roof prism 1.
07, and the eyepoint 2 of the photographer's eyeball 200 through the eyepiece lens 11 having the beam splitter 11a.
00a. Further, a part of the light flux of the subject image diffused by the focusing plate 105 is part of the penta roof prism 106.
The light is transmitted through the reflection surface 106a of the image forming device and is imaged on the light receiving surface of the AF area sensor 108 via the AF image forming lens 107.

On the other hand, in the visual axis detecting optical system, the infrared LED 1
The infrared light from 2 is reflected by the beam splitter 11a via the light projecting lens 13 and is emitted from the exit surface of the finder as substantially parallel light to the eyeball 200 of the photographer. Then, a part of the infrared light reflected by the eyepoint 201a of the eyeball 200 is re-reflected by the beam splitter 11a and is condensed on the line sensor 16 via the half mirror 17 and the light receiving lens 15 to form an eyeball image. To be imaged.

The image information of the eyeball photoelectrically converted by the line sensor 16 becomes an output signal as shown in FIG. 3, for example, and in the CPU 50 (not shown), the photographer based on the first Purkinje image 30 appearing in this output signal. The line-of-sight direction of is calculated.

Here, the CPU 50, as shown in FIG. 5, has a first release switch 57a, a second release switch 57b, a power switch 57c, various mode setting sections 51, an automatic focusing (AF) device 55, and an exposure control section 5.
6, the display unit 52, the LED 12, and the line sensor 16 are connected to control each.

Then, the AF device 55 is further shown in FIG.
As shown in FIG. 5, the AF area sensor 108, the photographing lens driving unit 551, and the lens position encoder 552 are provided. By designating the focus area, the focus can be adjusted by obtaining the first Purkinje image at an arbitrary position. .

The operation of the camera having the visual axis detection device according to this embodiment will be described below with reference to the flowchart of FIG.

That is, the CPU 50 first initializes I / O, registers and the like (step S101), and checks whether the main switch of the camera is "on" or "off" (step S102).

In step 102, if the main switch is "off", the operation is terminated (step S103), and if it is "on", the timer 2 is turned on.
Is checked up to a predetermined value (step S104). The timer 2 is used to save power by stopping the power supply inside the camera for, for example, about one minute when the photographer does not operate the camera for a predetermined time, and is reset by the initialization in step S101 above. Timing is performed separately from the processing operation of the CPU 50.

In step S104, if the predetermined time has elapsed since the last camera operation, the CPU 50
Stops the power supply to save power, and stops the clock to bring down the system (step S105). This CPU
From the stop state of 50, it can be started by an interrupt switch connected to the CPU 50 (step S
106, S107).

On the other hand, in step S104, if a predetermined time has not passed from the last camera operation, a line-of-sight detection subroutine as described later is executed (step S108). In this visual axis detection subroutine, visual axis detection calculation and detection results are displayed.

Next, it is determined whether or not the photographer is looking through the viewfinder based on the above-mentioned line-of-sight detection result. this is,
The determination is made by checking whether the detection flag F0 is "1" (step S109).

In step S109, when the detection flag F0 is "0", it is determined that the visual axis detection subroutine could not detect. At this time, the photographer may close his eyes, so the flag F1 of the previous detection result is also checked (step S110), and the detection flag F is detected.
When 1 is “0”, it is judged that you are not looking, and F1 is set to F
After setting to 0, the process proceeds to step S112. Then, after waiting for a predetermined time (step S112), step S1
Returning to 02, when the system should not go down, the sight line detection is executed again (step S108). The reason for waiting for a predetermined time in step S112 is to secure the detection interval of the line-of-sight detection. As described above, the current consumption can be reduced by detecting after a certain period of time.

On the other hand, in step S109, when the detection flag F0 is "1", it is determined that the visual axis can be detected in the visual axis detection subroutine. Similarly, when F0 is "0" and F1 is "1", it is determined that the sight line can be detected.

Then, after determining that the photographer is looking through the viewfinder together, F1 = F0 is set (step S11).
3) Then, in the next step S114, if it is determined that the photographer is looking into the viewfinder, the timer 2 is reset.

Next, it is checked whether the first release switch is "on" or "off" (step S115). If the 1st release switch is "off", the process returns to step S102, and if the 1st release switch is "on", it is determined whether or not the mode can be switched according to the line-of-sight detection result (step S116). .

In the present embodiment, the photographer directs his line of sight to the mode mark 40 shown in FIG.
The mode can be switched by pressing the 1st release switch.

When the line-of-sight direction is on the mode mark 40 in step S116, the mode is switched according to the selection (step S117), and the process returns to step S102. Then, when the line-of-sight direction is not on the mode mark 40, it is assumed that the line-of-sight direction is the direction of the auto-focus target, and according to the result, the photometry data acquisition and the focus detection area are selected to perform the focus detection and focusing AF. The operation is performed (step S118). This A
After the F operation, the “on” and “off” of the second release switch are checked (step S119).

If the 2nd release switch is not turned on in step S119, the 1st release switch is checked again for "on" or "off" (step S120). Then, if the 1st release switch is not "off", the process returns to step S102, and if the 1st release switch is "on", the photographer is waiting for a photo opportunity, so the timer 2 is reset. Then (step S12
1) Return to 2nd release switch detection (step S
119).

On the other hand, in step S119, 2
If the nd release switch is turned on,
Exposure and film winding are performed (step S12).
2, S113).

The operation of the visual axis detection subroutine will be described below with reference to FIG. The CPU 50 first turns on the infrared LED 5 which is the light source (step S
201), reset the CCD image sensor 6 as the light receiving means, and start integration (step S202). The image sensor 6 has a built-in light quantity monitor for controlling the integrated light quantity, and performs integration according to the output of the light quantity monitor, and when the integration is completed, notifies the CPU 50 of the completion of the integration.

Next, the CPU 50 waits for the integration of the image sensor 6 to end (step S203), and after the integration ends, LE
D5 is turned off (step S204).

Then, the CPU 50 detects the eyepiece from the integration time (step S205).

Here, if the photographer is looking into the viewfinder, a predetermined level of reflected light should be obtained, so if the amount of reflected light deviates greatly from this predetermined level, it is determined that the photographer is not looking into the viewfinder. can do.

In step S205, when the integration time is not within the predetermined range, it is determined that the eye data is not read without reading the image data, and the subroutine is exited.
When the integration time is within the predetermined range, the image data is read from the sensor 6, A / D converted and written in the internal random access memory (step S20).
6).

Then, the CPU 50 detects the first Purkinje image and the iris edge, which are the features of the eyeball image, from the captured image data, and calculates the line-of-sight direction from the coordinates thereof (step S207).

Here, the detection of the line-of-sight direction is calculated from the position of the first Purkinje image, which is the reflected light on the corneal surface, and the center position of the iris, for example, by the technique disclosed in JP-A-61-272552. can do. In addition, when the photographer is not looking into the finder or when the eyes are closed, an eyeball image cannot be obtained and the line-of-sight direction cannot be detected.

In this way, the CPU 50 determines whether or not the line of sight has been detected (step S208). Whether or not this is detected is determined by whether the obtained sensor signal matches a predetermined pattern, or whether the amount of light obtained by the sensor is within a predetermined range.

When the line of sight of the photographer can be detected in step S208, the detection flag F0 is set to "1" (step S210), and then the line of sight of the liquid crystal display element 111 placed near the focus plate 104 is set. It is displayed (step S211).

When the detection cannot be made, the detection flag F0 is set to "0" (step S209) and the process returns.

Thus, the line-of-sight position of the photographer is shown in FIG.
As shown in, a superimpose display 41 is displayed in the viewfinder display.

FIG. 9A shows a time chart in which eyepiece detection is continued when the photographer is not looking through the viewfinder, and FIG. 9B is an eyepiece detection when the photographer is looking through the viewfinder. -It is a figure which shows the time chart which continues the line-of-sight direction.

As can be seen from FIGS. 9A and 9B, the time interval of one detection is different depending on the eyepiece detection. Accurate gaze detection is realized by repeating the detection in small time when the eye is in contact, and current consumption is suppressed by opening an interval when the eye is not in contact.

Here, the AF area sensor 108 in the present embodiment receives the image of the focus surface, and the contrast AF is performed by detecting the contrast of this image.

Then, the photographic lens 101 is driven to two predetermined positions, the contrast of a predetermined spatial frequency is extracted from the image obtained at this time, and the frequency component ratio is calculated to obtain a frequency component ratio table specific to the photographic lens. By comparing, the defocus amount of the lens is calculated. Since this technique is known from Japanese Patent Laid-Open No. 2-275916, detailed description thereof will be omitted here.

As described above, in the present embodiment, the eyeball image is detected as compared with the eyepiece sensor which simply detects the reflected light of the eyepiece portion. Therefore, it is not related to whether the photographer is looking into the eyepiece or the photographing. It is possible to reliably judge whether the objects are close to each other.

FIG. 10 is a diagram showing the structure of the visual axis detection device adopted in the second embodiment of the present invention. In the following description of the present embodiment, the same contents as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The present embodiment is characterized in that an eyepiece detecting means 18 is further provided in addition to the constitution of the first embodiment described above. That is, the eyepiece detecting means 18 is provided in the vicinity of the finder as shown in FIG. 11, and detects that the photographer brings his or her face close to the camera, and is of a pyroelectric sensor or infrared reflector type. It has been known.

The operation of this embodiment will be described below with reference to FIG.

The CPU 50 first initializes I / O, registers and the like (step S301), and checks "ON" and "OFF" of the main switch of the camera (step S302).

In step 302, if the main switch is "off", the operation is ended (step S303), and if it is "on", the timer 2 is turned on.
Is checked up to a predetermined value (step S304).

This timer 2 is for stopping the power supply to the inside of the camera to save power, for example, for about 1 minute when the photographer does not operate the camera for a predetermined time, and is reset by the initialization in step S301. Cage
Timing is performed separately from the processing operation of the PU 50.

In step S304, if the predetermined time has passed since the last camera operation, the CPU 5
For 0, the power supply is stopped to save power, and the clock is stopped to bring down the system (step S305). This CP
From the stopped state of U50, it can be started by an interrupt switch connected to the CPU 50 (steps S306 and S307).

On the other hand, in step S304, if a predetermined time has not elapsed since the last camera operation, face-contact detection is performed (step S308). Then, it is determined whether or not the photographer brings his face close to the camera based on the face contact detection result (step S309).

If it is determined in step S309 that the photographer does not approach his face, step S3
Returning to 02, if it is determined that the photographer is approaching the face, the above-described line-of-sight detection subroutine is executed (step S310). Then, based on the result of the line-of-sight detection, it is detected whether or not the photographer is looking through the viewfinder (step S311).

Thus, when it is determined that the photographer is looking into the viewfinder, the timer 2 is reset (step S312). Then, it is checked whether the 1st release switch is "on" or "off" (step S31).
3).

If the 1st release switch is "OFF" in step S313, the process returns to step S302. Then, if the 1st release switch is "ON", it is determined whether or not the mode is switched according to the result of the sight line detection (step S31).
4).

In step S314, when the line-of-sight direction is on the mode mark, the mode is switched according to the selection (step S315), and step S315.
Return to 302. Then, when the line-of-sight direction is not in the mode selection, it is assumed that the line-of-sight direction is the direction in which the AF target exists, and according to the result, the data acquisition for photometry and the distance measurement area are selected, and the AF operation for distance measurement and focusing is performed ( Step S316).

After the AF operation, the 2nd release switch is checked for "on" or "off" (step S3).
17).

If the 2nd release switch is not turned on in step S317, the 1st release switch is checked again for "on" or "off" (step S318). If the 1st release switch is not "off", the process returns to step S302, and if the 1st release switch is "on", the photographer is waiting for a photo opportunity, so the timer 2 is reset. Then (step S31
9) Return to detection of the 2nd release switch (step S317).

On the other hand, in step S317, 2
If the nd release switch is turned on,
Exposure and film winding are performed (step S32).
0, S321).

As described above, in this embodiment, since the eye-gaze detection sensor starts the eye-gaze detection prior to the eye-gaze detection, useless power consumption can be reduced.

Although the embodiments of the present invention have been described above, it goes without saying that various modifications can be made without departing from the spirit of the present invention. For example, in the above embodiment, the focusing device is the contrast AF using the AF area sensor 108 mounted in the finder, but it may be a phase difference detection AF having a plurality of line sensors.

Although the line-of-sight detection is calculated from the first Purkinje image and the center position of the iris, it may be calculated from the iris, the sclera, and the edge, for example. Further, in the above-described embodiment, when it is possible to detect the eye contact by detecting the line of sight and determine that the photographer is not looking into the apparatus, the power supply to the photometry circuit and the distance measurement circuit in the apparatus may be stopped.

As described in detail above, according to the present invention, when the photographer looks into the viewfinder, the visual axis detection can be automatically started, so that the power consumption can be suppressed. Then, by using the line-of-sight detection sensor as an eyepiece detection sensor and switching the detection interval according to the detection result, it is possible to realize automatic startup of the device with a simple configuration and to achieve an unprecedented power saving effect. Can be issued. Furthermore, in the present embodiment, as compared with the eyepiece sensor that detects the reflected light of the mere eyepiece portion, since the eyeball image is detected, whether the photographer is looking in or an object unrelated to the photography is There is also an effect that it can be surely determined whether or not they are close to each other. In addition, since the eye-gaze detecting device itself detects the eyepiece, the cost can be kept low.

[0080]

According to the present invention, it is possible to provide a camera having a visual axis detection device with a simple structure and reduced power consumption.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of the present invention.

FIG. 2 is a diagram showing a configuration of a visual line detection device adopted in the first embodiment of the present invention.

FIG. 3 is a diagram showing a state of a first Purkinje image detected from reflected light from an eyeball.

FIG. 4A is a view showing a view in the finder, and FIG. 4B is a view showing a superimpose display in the viewfinder.

FIG. 5 is a diagram for explaining a function of a CPU 50.

FIG. 6 is a diagram showing a detailed configuration of an automatic focusing device 55.

FIG. 7 is a flowchart showing the operation of the first embodiment.

FIG. 8 is a flowchart showing a serve routine of eye gaze detection processing.

FIG. 9 is a diagram showing a time chart of eye gaze detection,
(A) shows a time chart without eye contact, and (b) shows a time chart with eye contact.

FIG. 10 is a diagram showing a configuration of a visual line detection device adopted in a second embodiment of the present invention.

FIG. 11 is a diagram showing the position of the eyepiece detection device in the camera.

FIG. 12 is a diagram for explaining the function of the CPU 50.

FIG. 13 is a flowchart showing the operation of the second embodiment.

[Explanation of symbols]

1 Detection light irradiation unit 2 Photoelectric converter 3 Gaze direction calculator 4 Eyepiece state detector 5 Detection mode switching section 6 control unit

Claims (2)

(57) [Claims] 1. A signal output means for outputting a signal in response to a photographing preparation operation by a photographer, a detection light irradiating section for irradiating the eyeball of the photographer with light, and a reflected light of the irradiation light from the eyeball. Then, a line-of-sight detection unit having a photoelectric conversion unit that performs photoelectric conversion and a line-of-sight direction calculation unit that detects the line-of-sight direction of the photographer based on a signal from the photoelectric conversion unit; When the signal is output, the determination means for determining whether or not the eyeball of the observer is present in the eyepiece part of the camera based on the signal from the photoelectric conversion section, and the eyeball is not present by the determination means. If it is determined that, regardless of the signal output state of the signal output means,
A camera, comprising: a control unit that controls so as not to perform a gaze direction calculation operation by the gaze direction calculation of the gaze detection unit. 2. The camera according to claim 1, wherein the signal output means detects that an object approaches a viewfinder of the camera and outputs a signal.