JPH07289518A - Line of sight detector, wink detector and camera - Google Patents

Abstract

PURPOSE:To perform the detection of the line of sight with high accuracy and that of a winking state while attaining a low cost and space saving. CONSTITUTION:Polarizing means 43-45 with mutually different polarizing phases are provided in front of an illumination means 12 and in front of photoelectric conversion means 25, 26, respectively, and a regular reflection ghost by an article other than the eyeball and the periphery of the eyeball (eyelid) of an observer (photographer) i.e., spectacles when they are used can be eliminated by each polarizing means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line-of-sight detection device and a blink detection device provided with illumination means for illuminating the eyes of an observer and photoelectric conversion means for detecting light reflected by the illumination means, or any of these. The present invention relates to an improvement of a camera equipped with such a device.

[0002]

2. Description of the Related Art There are the following methods for removing specular reflection ghosts of eyeglasses and sunglasses in a conventional visual axis detection device.

1) A line-of-sight detecting device is known in which the means for holding the light emitting / receiving element has a spectacle shape, as disclosed in JP-A-63-240860. This type of device is used by spectacle users. Even if there is, it is easy to change the structure so that it can be used (for example, a structure that can be attached to and detached from glasses). However, when such a device is used in this way, specular reflection ghosts occur as described above,
To eliminate this, it is necessary to adjust the optical axis by moving the mounting position or angle of the light projecting element or the light receiving element so that the light receiving element is located in a position where the light beam emitted by the light projecting element is not regularly reflected by the spectacle lens. There is.

The above-mentioned conventional example 1) is a case in which the line-of-sight detection system and the glasses are integrated and each target position can be specified, while 2) the conventional example in the system in which the line-of-sight detection system and the position of the glasses cannot be specified. , It is determined whether or not the photographer is using the eyeball (Japanese Patent Laid-Open No. 4-138432), and when wearing glasses, the configuration of the line-of-sight detection system is changed (the auxiliary lens is inserted or the detection sensor position is changed). To be changed)
No. 138431).

3) A device that reduces the power of illumination light when detecting glasses (JP-A-3-109028).

4) A method in which a plurality of lighting means are installed and they are selected depending on the presence / absence of specular reflection of the spectacles (Japanese Patent Laid-Open No. Hei 4-
264290).

[0007]

However, the above-mentioned conventional examples have the following problems, respectively.

In the above 1), adjusting the position of the light projecting element or the light receiving element so that the specular reflection ghost due to the eyeglasses does not occur means that it takes time to adjust the optical axis before the sight line detection. required, and the further optical axis adjustment becomes necessary human to adjust separately is not able to perform alone.

In the above 2), some kind of drive actuator is required to change the configuration of the visual axis detection system upon detection of wearing of eyeglasses or sunglasses, and a space therefor is required in the camera. Not only does it cost more. Further, it is practically difficult to change the sensor position while maintaining the visual axis detection accuracy.

In the above 3), if the illumination light power is reduced, the reflected light from the eyeball also decreases, and it is not possible to obtain the S / N for securing the visual axis detection accuracy.

In the above 4), if a plurality of lighting means are installed, the installation space is required and the cost is increased. Further, since the specular reflection position varies between the line-of-sight detection system and the eyeglasses due to the distance or inclination, the curvature of the eyeglass lens, and the like, the number of light projecting elements increases in order to deal with all of them.

(Objects of the Invention) A first object of the present invention is to achieve cost reduction and space saving, as well as a visual axis detection device and a blink detection apparatus capable of performing highly accurate visual axis detection and blink state detection. And to provide a camera.

A second object of the present invention is a line-of-sight detection device capable of achieving the above first object with higher accuracy,
An object is to provide a blink detection device and a camera.

A third object of the present invention is to achieve high-precision line-of-sight detection and blinking state detection while achieving cost reduction and space saving without giving glare to the user. An object of the present invention is to provide a line-of-sight detection device, a blink detection device, and a camera.

A fourth object of the present invention is to provide a line-of-sight detecting device, a blink detecting device and a camera capable of achieving the third object with high accuracy.

[0016]

In order to achieve the first object, the present invention according to claim 1, 4, 5 or 8 provides a polarization phase for each of the front surface of the illumination means and the front surface of the photoelectric conversion means. Different polarizing means are provided, and objects other than the eyes of the observer (photographer) or the area around the eyes (eyelids), that is, specular reflection ghosts generated when spectacles are used are removed by the respective polarizing means.

In order to achieve the above-mentioned second object, the present invention according to claim 2 is configured such that the polarization phase of the polarization means arranged in front of each of the illumination means and the photoelectric conversion means is different by approximately 90 degrees. ing.

In order to achieve the third object, the present invention according to claim 3 or 7 provides an illuminating means for projecting a light flux containing at least a wavelength in the infrared region, a front surface of the illuminating means and a front surface of the photoelectric converting means. And a polarization means having polarization characteristics in the wavelength of the infrared region is provided, infrared light that is insensitive to an observer (photographer) is used as an illumination means, and a specular reflection ghost when glasses are used It is configured to be removed by means.

In order to achieve the above-mentioned fourth object, the present invention according to claim 6 is configured such that the polarization phase of the polarization means arranged in front of each of the illumination means and the photoelectric conversion means is different by approximately 90 degrees. ing.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the illustrated embodiments.

FIG. 1 is a mechanism diagram showing an outline of a camera with a visual axis detecting function in a first embodiment of the present invention.

In FIG. 1, 1 is a system controller for performing sequence control and calculation, 2 is a ROM for storing programs and data, and 3 is an RA for storing data.
M, 4 are photometric circuits for measuring the light amount of the subject, 5 are distance measuring circuits for measuring the distance from the camera to the subject, 6 is a drive circuit for a shutter (not shown) for exposing the film, and 7 is the operation of the camera. A main switch for switching between a state and an inoperative state, 8 is a release switch for instructing exposure on the film, 9 is a tele switch for zooming in the tele direction, and 10 is a wide switch for zooming in the wide direction.

Reference numeral 11 denotes a zoom variable magnification photographing optical block, and 12
Is a rack gear integrated with the zoom magnification / photographing optical block 11, 13 is a pin-on gear, 14 is a zoom magnification motor, 1
Reference numeral 5 is a motor driver, and 16 is a photographic film. 17
Is a transmissive LCD installed at a predetermined position in the finder optical system of the camera, 17a is a screen center display, 17b is a zoom wide direction index, 17c is a zoom tele direction index, and 18 is an LCD driver for driving the LCD 17.

Reference numeral 19 denotes an infrared LED for eyeball illumination (hereinafter referred to as iR) for detecting that the photographer has contacted the viewfinder.
ED), 20 is its constant current driver, 21 is a phototransistor for detecting reflected light, 22 is its detection circuit, 2
Reference numeral 3 denotes an infrared LED for line-of-sight detection (hereinafter referred to as iRED),
24 is the constant current driver. Reference numeral 25 is a photodiode that detects reflected light on the eyeball in the area on the left side of the eyeball optical axis of the line-of-sight detection iRED 23, and 26 is reflected light on the eyeball in the area on the right side of the same eyeball optical axis. Photodiodes 27 and 28 are resistors for converting the photocurrent detected by the photodiodes 25 and 26 into a voltage. 29 and 30 are operational amplifiers, the output of each operational amplifier V _L, and V _R. Reference numeral 31 is a signal selection circuit, and 32 is an AD converter.

Reference numeral 43 denotes a polarizing plate arranged on the front surface of the above-mentioned line-of-sight detecting iRED 23, and its polarization direction is set to a predetermined direction. 44 and 45 are the photodiodes 2
The polarizing plates are arranged in front of Nos. 5 and 26, and have a polarization direction different from that of the light-projecting side polarizing plate 43 by 90 degrees.

FIG. 2 is an external perspective view of the camera having the above-mentioned structure as seen from above the front surface. The same components as those in FIG. 1 are designated by the same reference numerals.

FIG. 3 is an external perspective view of the camera as seen from below the rear surface of the camera, and FIG. 4 is an enlarged view of the viewfinder eyepiece portion shown in FIG.

In FIG. 4, the iRED 19 for illuminating the eyeball and the photodiode 21 for detecting the reflected light thereof are installed in the lateral direction of the eyepiece lens 33. Further, the line-of-sight detection iRED 23 and the reflected light detection photodiodes 25 and 26 thereof are installed below the eyepiece lens 33 and are configured to detect eyeball reflected light at a slightly elevated angle. Reference numeral 40 denotes the horizontal center of the finder optical axis.

5 to 7 are views showing a state in which the axes of the eyeball and the detection area are deviated.

FIG. 5 shows a state in which there is no horizontal displacement between the optical axis of the eyeball and the center axis of the visual axis detection system, and FIG. 5A is a view of the eyeball and the detection system as seen from above.
The eyeball illumination state and the detection angles of the left and right photodiodes 25 and 26 are shown.

Here, with respect to the central axis 40, left (L) and right (R) are designated as shown in the figure. 34 is the eyeball, 35 is the black eye (pupil and iris) part of the eyeball, 36 is the pupil, 37
Is an iris. 38 is a detection area by the photodiode 25 on the left side, 39 is a detection area by the photodiode 26 on the right side, and 46 is a white eye (sclera) of the eyeball.

FIG. 5B is a diagram showing the positions of the iris and the left and right detection areas when the line of sight is directed to the center.
FIG. 5C is a diagram in which the line of sight is directed to the left, and FIG. 5D is a diagram in which the line of sight is directed to the right.

FIG. 6 is a diagram showing a state in which the eyeball axis is shifted to the right in the horizontal direction with respect to the optical axis 40 of the line-of-sight detection system, and FIG. 7 is a diagram showing a state in which it is shifted to the left in the horizontal direction, conversely.

FIG. 8 is a diagram showing the output change difference (right output-left output) characteristics of the left and right photodiodes 25 and 26 with respect to the viewing angle in the state where the eye axis is not displaced with respect to the optical axis 40 of the visual axis detection system.

FIG. 9 is a diagram showing the output change difference (right output-left output) characteristics of the left and right photodiodes 25 and 26 with respect to the viewing angle when the optical axis of the eyeball is horizontally displaced with respect to the detection system.

FIG. 10 is a diagram showing characteristics in a state of being shifted to the left.

FIG. 11 is an optical path diagram of the finder optical system. Reference numeral 41 is an objective lens block and 42 is a field lens. The objective lens block 41 is moved according to the magnification change of the photographing lens block 11 shown in FIG. The magnification of the finder can be changed by moving it in the axial direction. Details of the interlocking mechanism are omitted.

FIG. 12 is a diagram for explaining the polarization state of the illumination light due to the diffuse reflection on the eyeball, and FIG. 13 is a diagram for explaining the polarization state of the spectacle lens 47 for the illumination light due to the regular reflection.

Next, the operation of the first embodiment of the present invention will be described with reference to the flowchart of FIG.

When the main switch 7 is turned on, the system controller 1 starts operation from step 102 via step 10101. [Step 102] The iRED 19 for eyeball illumination is turned on. [Step 103] It is determined whether or not the reflected light detecting phototransistor 21 detects a reflected light amount equal to or more than a predetermined amount. As a result, if a reflected light amount of a predetermined amount or more is detected, it is determined that the photographer has contacted the viewfinder, and step 1
Go to 04. On the other hand, if there is no reflected light above a predetermined level, the process proceeds to step 125.

Here, assuming that the amount of reflected light of a predetermined amount or more is detected, the operation after step 104 will be described first. [Step 104] The segment of the screen center display 17a showing the center of the LCD 17 in the finder is turned on. [Step 105] The timer T _D for counting the delay time until the offset data acquisition is started. [Step 106] It is determined whether or not the count of the timer T _D has passed a predetermined time. If the predetermined time has not elapsed, the process remains in this step, and if the predetermined time has elapsed thereafter, the process proceeds to step 107. [Step 107] The eye-gaze detecting iRED 23 for detecting the eye-gaze is turned on. [Step 108] calculates a difference in the amount of reflected light by the photodiode 25, 26 is detected (V _R -V _L), which is the offset voltage (V _offset).

Details of the operation of detecting the outputs of the photodiodes 25 and 26 by the system controller 1 are shown below.

In FIG. 1, photodiodes 25, 2
The photocurrent detected by 6 is converted into current / voltage by the resistors 27 and 28, respectively, and one of the two is selected by the signal selection circuit 31. The selected signal is the AD converter 3
2 is quantized with a predetermined resolution and is input to the system controller 1.

The eyeball 34 is the iRED 23 for line-of-sight detection.
Not only is it illuminated by ambient light at the same time,
It is essential to remove those external light components. This is because, in addition to the optical removal of external light by covering the light-receiving surfaces of the photodiodes 25 and 26 with a visible-light cut filter, the line-of-sight detection iRED 23 is electrically modulated at a predetermined frequency to allow the photodiodes 25 and 26 to operate. The frequency characteristic of the detection system can be easily realized by a known synchronous detection method in which a high-pass filter characteristic matched with the frequency characteristic is provided, and details thereof will be omitted here.

Here, the offset voltage (V _offset ) will be described.

First, when the photographer holds the camera, and the eyepiece position is zero in horizontal displacement from the optical axis of the finder optical system, as shown in FIG. 5, the optical axis 40 of the visual axis detection system and the optical axis of the eyeball are It matches. At this time, the position of the detection area on the eyeball with the line of sight looking at the center is shown in FIG.
It is shown in (b). In FIG. 5B, as described above, 38 is the detection area of the left photodiode 25, 3
Reference numeral 9 is a detection area of the right photodiode 26.

As shown in FIG. 5 (a), the directional characteristics of the detection of the photodiodes 25 and 26 are limited to a spot shape limited on the eyeball by a light receiving lens, a diaphragm mask, etc. (not shown). It is configured to form a detection area.

When there is no horizontal displacement between the optical axis of the eyeball and the optical axis 40 of the line-of-sight detection system, as shown in FIG. 5B, the proportion of white eyes and black eyes in the left and right detection areas is equal.
The output difference between the left and right (V _R -V _L) is zero, is calculated as the offset voltage zero. Here, the iris means the pupil 36 and the iris 37 shown in FIG. 5B, as described above.

On the other hand, when the eyeball optical axis is shifted to the right in the horizontal direction with respect to the optical axis 40 of the visual axis detecting system [the state of FIG. 6 (a)], the left and right eyes with the visual axis pointing to the center are provided. As for the ratio of white / black eyes in the detection area, as shown in FIG. 6B, the black eyes occupy more in the detection area 39 of the photodiode 26 on the right side. Therefore, the line-of-sight detection i
The amount of light reflected by the RED 23 is the photodiode 2 on the left side.
5 is detected as more, and each photodiode 2
The difference between the output voltage of 5,26 is next "V _R -V _L <0 (negative)", this value becomes the offset voltage (V _offset).

On the contrary, when the optical axis of the eyeball is shifted to the left in the horizontal direction with respect to the optical axis 40 of the visual axis detecting system (the state of FIG. 7B), the left and right in the state where the visual axis is directed to the center. As for the ratio of white eye / black eye in the detection area, the black eye portion is more occupied in the detection area 38 of the left photodiode 25, as shown in FIG. 7B. Therefore, the difference between the output voltage of the photodiode 25, 26 'V _R -V _L
> 0 (positive) ”, and this value is the offset voltage (V
_offset ).

Next, the operation after calculating the offset voltage value will be described. [Step 109] The offset voltage value (V _offset ) is stored in the RAM 3. [Step 110] The segment of the screen center display 17a showing the center of the LCD 17 in the finder is turned off. [Step 111] The reflected light amount level of the phototransistor 21 is discriminated again to discriminate whether or not the eyepiece state is still continued. As a result, if the reflected light amount is equal to or more than the predetermined level, the process proceeds to step 112, and if it is less than the predetermined level, the process proceeds to step 127.

Here, it is assumed that the amount of reflected light is less than the predetermined level, and the process proceeds to step 127. [Step 127] The eye-gaze detecting iRED 23 is turned off, and the process proceeds to step 125 described later.

In step 111, if the amount of reflected light is equal to or higher than the predetermined level, the process proceeds to step 112 as described above, and the line-of-sight detection is started to be used for zooming control. [Step 112] Left and right photodiodes 2 again
Detecting the output of 5,26, each output difference (V _R -V _L)
The voltage value obtained by subtracting the offset voltage (V _offset ) stored in step 109 is calculated as the visual axis detection output V _Eye . [Step 113] The value of the visual axis detection output (V _Eye ) is compared with predetermined values V _{1 to} V ₄ (see FIGS. 8 to 10). If it is determined that “V ₂ <V _Eye <V ₁ ”, the process proceeds to step 114, and if it is determined that “V ₄ <V _Eye <V ₃ ”, the process proceeds to step 118.

Correspondence between the visual axis detection output (V _Eye ) and the visual angle will be described with reference to FIGS. 8 to 10.

Firstly, the corresponding viewing angle in the viewfinder to the difference output of the photo diode 25, 26 right and left when the deviation amount in the horizontal direction of the eyeball optical axis and the visual axis detection system optical axis 40 is zero (V _R -V _L) The characteristics indicated by are as shown by the thick line in FIG. That is, with respect to the difference between the output (V _R -V _L) is the center of the left and right photodiodes 25 and 26, a pair on the left and right viewing angle 1
By detecting this difference output, the horizontal component of the part of the finder that the photographer is gazing at can be detected. Transmissive LCD 17 installed in the viewfinder
The horizontal visible range in the finder optical system of
This is the range indicated by the alternate long and short dash line in FIG.

The installation positions of the zoom tele direction indicator 17c and the zoom wide direction indicator 17b installed on the LCD 17 in the finder with respect to the viewing angle are as follows.

The zoom telescopic direction indicator 17c is a viewing angle of A ₂ or more and A ₁ or less, and the zoom wide direction indicator 17b is A _{3 or more.}
Above, A ₄ below, are placed respectively. The difference between the left and right outputs of the photodiodes 25 and 26 corresponding to these viewing angle (V _R -V _L), the zoom wide direction indicator 17c V
_Tele-Min (= V ₂ ) or more, V _Tele-Max (= V ₁ ) or less,
The zoom wide direction index 17b is set to be V _Wide-Min (= V ₄ ) or more and V _Wide-Max (= V ₃ ) or less.

Here, it goes without saying that when the horizontal shift between the optical axis 40 of the visual axis detection system and the optical axis of the eyeball is zero, it passes through the origin.

Next, when the optical axis of the eyeball is shifted to the left or right, the characteristic is shifted with respect to the origin, as shown by the thick line in FIG. 9 or 10. The optical axis of the eyeball is the optical axis 40 of the visual axis detection system.
On the other hand, if it shifts in the horizontal right direction, a negative offset voltage (FIG. 9) is generated, and conversely, if it shifts in the horizontal left direction, a positive offset voltage (FIG. 10) is generated.

Therefore, in step 112, the outputs (V) of the left and right photodiodes 25 and 26 detected are detected.
_R, the difference between the output of the _{V L) (V R -V L} ) from Step 1
By reducing the offset voltage (V _offset ) stored in 19, the characteristic of the thick line is corrected to the characteristic passing through the origin (shown by the dotted line in FIG. 9 or 10).

[0061] Then, in step 113, the detected differential output of the left and right photodiodes 25,26 (V _R -V _L) is the corrected output gaze detection output V _Eye
When _{(= V R -V L -V offset} ) is determined to be within a predetermined range, the process proceeds to step 114 or step 117. [Steps 114 and 117] It is determined whether or not the above state continues for a predetermined time or longer. If it is determined that each index is being watched for a predetermined time or longer, the process proceeds to step 115 or step 118. [Steps 115, 118] A predetermined amount of power is supplied to the zoom driver 15 in the direction of the gazed index, and the zoom variable magnification motor 14 is driven to set the zoom variable magnification photographing lens block 11 of the image pickup system to the film 16. It is configured to move quantitatively.

Zoom variable magnification photographing variable magnification lens block 11
When the zoom variable power motor 14 is driven, the pinion gear 13 rotates and the rack gear 14 moves by linear movement in the optical axis direction. [Steps 116 and 119] Here, the mark corresponding to the detected zoom control direction is turned on to prompt the photographer to confirm that the line of sight has been detected and the corresponding processing has been performed. That is, if electricity is applied in the tele direction, the segment 17e
(T), segment 17d if energized in the wide direction
Each of (W) is configured to light for a predetermined time.

After the above-described mark lighting process, the process returns to step 111 again, and the eyepiece state is determined.

On the other hand, in step 113, the visual axis detection output (V _Eye ) is "V ₂ or more, V ₁ or less", or
If the state is neither "V ₄ or more and V ₃ or less", the process proceeds to step 120. [Step 120] The state of the release switch 8 is determined, and if it is on, the process proceeds to step 121. On the other hand, if it is not turned on, the process returns to step 112, the outputs of the left and right photodiodes 25 and 26 are detected again, and the visual axis detection output (V _Eye ) is determined by the value obtained by subtracting the stored offset value (V _offset ). To do.

The case where the release switch 8 is turned on will be described. [Step 121] The photometric circuit 4 performs photometry. [Step 122] The distance measuring circuit 5 measures the distance to the subject. [Step 123] The shutter (not shown) is opened only for the time determined by the subject brightness measured in the above step 121 and the sensitivity of the film 16 mounted on the camera to expose the film 16. [Step 124] One frame of film is fed. The feeding means is not shown.

After the film is fed as described above, step 11 is performed again.
Returning to step 1, the eyepiece state of the photographer is detected.

When the reflected light detecting phototransistor 21 does not detect the reflected light amount of a predetermined amount or more in the above step 103, or after the eye gaze detecting iRED 23 is turned off in the step 127, the process proceeds to the step 125 as described above. And proceed. [Step 125] Here, it is determined whether or not the main switch 7 is turned off.
Returning to 03, the same operation is repeated. On the other hand, if it is off, the routine proceeds to step 126. [Step 126] The iRED 19 for eyeball illumination is turned off, and the process ends.

Needless to say, it is necessary to set so that the light emitted from the eyeball illumination iRED 19 enters the light receiving detection areas of the sight line detecting photodiodes 25 and 26 and does not affect the sight line detecting output. As a method for eliminating the influence, specifically, the detection area of the iRED 19 for eyeball illumination is provided with directional characteristics so that the line-of-sight detection areas 38 and 39 can be obtained.
There is an optical method of setting so as not to overlap with the above, and an electric method of performing the eyepiece detection in a time-division manner by shifting the timing of the above-mentioned synchronous detection of external light removal and the timing, but the detailed description thereof will be omitted here.

Next, the removal of specular reflection of glasses by the polarizing plates 43 to 45 will be described.

On the front surface of the line-of-sight detection iRED 23, as described above, the polarizing plate 43 having the polarization direction set to a predetermined direction.
Are installed on the front surfaces of the reflected light detecting photodiodes 25 and 26, and polarizing plates 44 and 45, respectively, whose polarizing directions are different by 90 degrees from the polarizing plate 43 for projecting light are installed.

Illumination light from the line-of-sight detection iRED 23 becomes linearly polarized light with a constant polarization direction by the light projecting side polarization plate 43 (see FIG. 12). With respect to the illumination light, the light reflected by the white eye portion 46 or the iris 37 becomes diffuse reflection.
As shown in (3), the polarization of the reflected light is a random polarization of 360 degrees. Photodiode 25, which is a light receiving element,
Since polarizing plates 44 and 45 are installed on the front surface of 26, a polarization component different from the polarization direction by 90 degrees is removed as shown in FIG. At this time, the amount of received light is 1 in principle.
/ 2.

On the other hand, in the case of regular reflection by glasses or sunglasses, the polarization direction due to the reflection does not change. Therefore, if the projection polarization direction and the reception polarization direction are different by 90 degrees, it is theoretically zero. (See Figure 13). Therefore, by disposing the light-projecting polarizing plate 43 and the light-receiving polarizing plates 44 and 45 so that the polarization directions thereof are different by 90 degrees, only the specular reflection component is selectively removed.

Here, when the above-mentioned glasses and sunglasses are not used, that is, when the naked eye is used, the amount of received diffuse reflected light is reduced to 1/2. Increase the current, or
By increasing the amplification degree of the detection circuit (resistor 27 to operational amplifier 30 in FIG. 1) (specifically, changing the values of the resistors 27 and 28), S / S similar to that when the polarizing plates 43 to 45 are not provided. N
It goes without saying that it is necessary to secure

(Second Embodiment) FIG. 15 is a mechanical view showing the outline of a camera with a visual axis detection function according to the second embodiment of the present invention. The same parts as those in FIG. Is omitted.

In the first embodiment described above, the transmission type polarizing plate 4
Although the polarization direction of the illumination light is controlled by means of No. 3, in the second embodiment, a polarization control film made of a combination of a metal film and a dielectric film is deposited on the beam splitter to control the polarization. It shows an example of the configuration.

In FIG. 15, reference numeral 48 denotes a beam splitter, which has a polarization control surface 48a having a metal derivative film deposited thereon.

The light transmitted (or reflected) by the polarization control surface 48a becomes a linearly polarized light having a constant polarization direction, and the polarization direction of the polarization plates 44, 45 installed in front of the photodiodes 25, 26 as light receiving elements. It is installed so that the polarization direction and the phase are different by 90 degrees. Further, in the present embodiment, the eye is illuminated by the light transmitted through the beam splitter 48, but it goes without saying that this may be reflected light.

By controlling the polarization of the light by the beam splitter 48 having the above-mentioned configuration, it is possible to illuminate with a smaller light amount loss as compared with the case where the polarization control is performed by the transmission type polarizing plate 43 of the first embodiment. It is possible.

According to each of the above-mentioned embodiments, the iR for line-of-sight detection is
ED23 and photodiode 2 for detecting the reflected light
Since the polarizing plates 43, 44, and 45 having different polarization phases of 90 degrees are arranged on the front side of 5 and 26,
It is not necessary to adjust the position of the light emitting / receiving element so as to prevent the specular reflection ghost from the eyeglasses prior to the line-of-sight input, and the usability can be improved.

Further, since the polarization means (polarizing plates 43 to 45 or the beam splitter 48) can selectively remove only the specular reflection component from the eyeglasses, a drive actuator for changing the configuration of the visual axis detection system is not required, and the camera is miniaturized. And low cost can be realized. Further, since the position of the light emitting / receiving element is not changed, high accuracy can be maintained.

Further, since it is not necessary to reduce the illumination light power, it is possible to maintain high visual axis detection accuracy.

Further, since it is not necessary to install a plurality of illumination means (iRED23), it is possible to save the installation space and reduce the cost. Further, even if the distance or inclination between the line-of-sight detection system and the eyeglasses or the curvature of the lens varies, only specularly reflected light can be selectively removed.

Further, by using the polarization beam splitter 48 to control the polarization of the illumination light for detecting the line of sight, it is possible to improve the illumination efficiency.

Furthermore, since the iRED emitting infrared light is used as the illuminating means and the polarizing means is made to have the polarization characteristic in the above infrared wavelength range, the photographer is not dazzled.

(Correspondence between Invention and Embodiment) In this embodiment, the line-of-sight detection iRED 23 corresponds to the illumination means of the present invention, the photodiodes 25 and 26 correspond to the photoelectric conversion means of the present invention, and the system controller 1 Corresponding to the line-of-sight position detecting means, the polarizing plates 43 to 45 and the beam splitter 4
Reference numeral 8 corresponds to the polarization means.

The above is the correspondence relationship between each configuration of the embodiments and each configuration of the present invention, but the present invention is not limited to the configurations of these embodiments, and a configuration capable of achieving the functions shown in the claims. It goes without saying that it may be of any type.

(Modification) The present invention can be applied to any camera such as a single-lens reflex camera, a lens shutter camera, and a video camera.

The case of application to a camera with a line-of-sight detection function has been described, but it goes without saying that it may be applied to a single line-of-sight detection device, and in recent years, a camera that performs release by blinking has been disclosed. Although disclosed by No. 40303, the invention can be applied to a blink detection device provided in this type of camera. In other words, if the camera is equipped with an optical device configured to activate some function by the user's observation, and a camera equipped with this type of device,
It is applicable to both.

Further, the polarizing plate 43 for projecting light and the polarizing plates 44, 45 for receiving light are set so that the polarization directions thereof are different by 90 degrees to remove the specular reflection component.
It seems ideal that the polarization direction is different by 0 degrees.) This is determined by the removal ratio (performance) of the specular reflection component of each polarizing plate and the desired amount of the specular reflection component removed, and this is not always the case. It is not limited.

Although iRED is used as the illumination means, it may be a light projecting element that projects visible light.

[0091]

As described above, according to the first, fourth, and fifth aspects.
Alternatively, according to the present invention as described in 8, the front surface of each of the illumination means and the photoelectric conversion means is provided with a polarization means having a different polarization phase, and an object other than the eyeball of the observer (photographer) or the eyeball periphery (eyelid), That is, when using glasses, the specular reflection ghost in this case is removed by each of the above-mentioned polarizing means.

Therefore, it is possible to perform highly accurate visual axis detection and blink state detection while achieving cost reduction and space saving.

Further, in the present invention according to claim 2, the polarization phase of the polarization means arranged on the front surface of each of the illumination means and the photoelectric conversion means is made to differ by approximately 90 degrees.

Therefore, it is possible to detect the line of sight and the blinking state with higher accuracy while achieving cost reduction and space saving.

According to the present invention as set forth in claim 3 or 7, the illuminating means for projecting a light flux containing at least a wavelength in the infrared region, and the illuminating means front face and the photoelectric converting means front face are respectively arranged, and the infrared region is provided. A polarizing means having a polarization characteristic at the wavelength of is provided, infrared light that is insensitive to an observer (photographer) is used as an illuminating means, and specular reflection ghost when using glasses is removed by each of the above polarizing means. There is.

Therefore, it is possible to perform high-precision gaze detection and blinking state detection while achieving cost reduction and space saving without giving glare to the user.

Further, in the present invention according to claim 6, the polarization phase of the polarization means arranged on the front surface of each of the illumination means and the photoelectric conversion means is made to differ by approximately 90 degrees.

Therefore, it is possible to detect the line of sight and the blinking state with higher accuracy while achieving cost reduction and space saving.

[Brief description of drawings]

FIG. 1 is a mechanism diagram showing a main part of a camera with a visual axis detection function according to a first embodiment of the present invention.

2 is an external perspective view of the camera of FIG. 1 as seen from above the front surface.

FIG. 3 is an external perspective view of the camera of FIG. 1 as viewed from below the rear surface thereof.

4 is an enlarged view of a viewfinder eyepiece shown in FIG. 3. FIG.

FIG. 5 is a diagram showing a state in which the axes of an eyeball and a detection area are deviated in the present embodiment.

FIG. 6 is a diagram showing a state in which the eyeball axis is horizontally displaced to the right with respect to the detection system axis in the present embodiment.

FIG. 7 is a diagram showing a state of being shifted leftward in the horizontal direction, which is the opposite of FIG. 6;

FIG. 8 is a diagram showing a line-of-sight output characteristic in a state where there is no eyeball axis shift with respect to the detection system in the present embodiment.

FIG. 9 is a diagram showing line-of-sight output characteristics in a state where the optical axis of the eyeball is horizontally displaced with respect to the detection system in the present embodiment.

FIG. 10 is a diagram showing a line-of-sight output characteristic in a state of being displaced to the left in the present embodiment.

FIG. 11 is a diagram showing a finder optical system in the first embodiment of the present invention.

FIG. 12 is a perspective view for explaining a polarization state of diffused reflection on an eyeball with respect to illumination light in the first embodiment of the present invention.

FIG. 13 is a perspective view for explaining the polarization state of specular reflection of the spectacle lens with respect to the illumination light in the first example of the present invention.

FIG. 14 is a flowchart showing an operation of the camera of the first embodiment of the present invention.

FIG. 15 is a mechanism diagram showing a main part of a camera with a visual axis detection function according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 System controller 19 iRED for eyeball illumination 21 Phototransistor 23 iRED for line-of-sight detection 25,26 Photodiode 31 Signal selection circuit 32 AD converter 43-45 Polarizer 48 Beam splitter

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location G02B 27/28 Z G03B 17/00 Q G02B 27/00 C

Claims (8)

[Claims] 1. An illumination means for illuminating the eyes of an observer, a photoelectric conversion means for detecting light reflected by the illumination means, and a visual line position detection means for detecting a visual line position from an output of the photoelectric conversion means. In the line-of-sight detection device, polarization units having different polarization phases are provided on the front surface of the illumination unit and the front surface of the photoelectric conversion unit, respectively. 2. The polarization phase of the polarization means arranged on each of the front surface of the illumination means and the front surface of the photoelectric conversion means is approximately 90.
The line-of-sight detection device according to claim 1, wherein the line-of-sight detection device is different. 3. The illumination means is means for projecting a light flux including at least a wavelength in the infrared range, and each of the polarization means is means having polarization characteristics at the wavelength in the infrared range. The visual line detection device according to item 1 or 2. 4. A camera comprising the line-of-sight detection device according to claim 1, 2, or 3. 5. Illuminating means for illuminating the eyes of an observer, photoelectric conversion means for detecting light reflected by the illuminating means, and blinking state detecting means for detecting the blinking state of the observer from the output of the photoelectric converting means. In the blink detection apparatus including: a blink detection apparatus, wherein the illumination means front surface and the photoelectric conversion means front surface are respectively provided with polarization means having different polarization phases. 6. The polarization phase of the polarization means arranged on each of the front surface of the illumination means and the front surface of the photoelectric conversion means is approximately 90.
The blink detection device according to claim 5, wherein the blink detection device has different degrees. 7. The illumination means is a means for projecting a light beam including at least a wavelength in the infrared region, and each of the polarization means is a means having a polarization characteristic in the wavelength in the infrared region. Item 5. The blink detection device according to item 5 or 6. 8. A camera comprising the blink detection device according to claim 5, 6, or 7.