JP4175020B2 - Finder device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical system having a zooming function and a finder device including an imaging unit.
[0002]
[Prior art]
A general sight has a lens that guides the light beam from the external target to the user's eye, and includes a crosshair that indicates the optical axis position of the lens and a crosshair with a division scale that indicates the prospective angle of the object. The reference mark is superimposed on the light flux from the external target so that it is far from the user's eyes.
[0003]
When the distance of the external target is varied, the sighting lens can be a lens with a variable magnification function, for example, a zoom lens with a variable position of some lens groups or a lens group with some lens groups. Possible variable magnification lenses are used.
By the way, with the rapid performance improvement of recent image sensors, a finder device for displaying an external target as an electronic image has been developed instead of this sighting device.
[0004]
According to the finder device, the user can take a relatively easy posture because he / she only has to look at the video displayed on the monitor or the like instead of looking through the sight.
When a crosshair is displayed in this finder device, the crosshair image may be drawn at the center (position corresponding to the optical axis) on the external target image (so-called CG).
However, since the size of an object with the same prospective angle also changes when the lens magnification is changed, when the user reads a crosshair with a divisional scale, the user must Is read as appropriate according to the lens magnification.
[0005]
[Problems to be solved by the invention]
However, when the lens magnification is changed, not only the unit of the division scale is changed, but also the optical axis of the lens may be shifted due to the play generated when the lens is driven, so that the center of the crosshair does not accurately indicate the optical axis. there is a possibility.
The unit of the division angle scale is uniquely determined by the lens magnification, but the actual magnification does not always exactly match the magnification intended by the user. Even if it is appropriately performed, there is a possibility that an accurate prospective angle cannot be obtained.
[0006]
In addition, the above problem can occur not only when the lens is driven, but also due to a change in lens aberration due to environmental changes such as temperature and vibration.
In particular, when the finder device is mounted on a moving body, the environmental change is large, so that the problem is expected to become serious.
Therefore, an object of the present invention is to provide a finder device that can accurately display a reference mark such as a crosshair or a crosshair with a divisional scale, regardless of a change in the state of an optical system.
[0007]
[Means for Solving the Problems]
The finder device according to claim 1, an optical system that forms an image of an imaging target and has a function of changing magnification, an imaging unit that acquires an image of the imaging target formed by the optical system, A predetermined reference object whose position is unchanged with respect to the optical system, a conversion optical system that converts a reference light beam emitted from the reference object into a light beam equivalent to a light beam emitted from infinity, and the converted reference light beam for the imaging target A light projecting unit having an integrated optical system that integrates an imaging light beam incident on the optical system from the optical system, and the image acquired by the imaging unit according to the image of the reference object detected by the imaging unit. And a reference mark superimposing unit for superimposing a reference mark.
[0008]
The finder device according to claim 2 is the finder device according to claim 1, wherein the reference object emits the reference light beam indicating at least one point in the field of view of the optical system, and the reference mark superimposing unit is The optical axis mark indicating the position of the optical axis of the optical system is superimposed as the reference mark.
The finder device according to claim 3 is the finder device according to claim 1 or 2, wherein the reference object indicates at least a line segment in a predetermined direction within the field of view of the optical system. A reference light beam is emitted, and the reference mark superimposing unit superimposes a division angle scale indicating an expected angle of an object as the reference mark.
[0009]
The finder device according to claim 4 is the finder device according to any one of claims 1 to 3, wherein the reference object is a mask on which a predetermined pattern is formed, and the light projecting unit is And a light source for illuminating the mask. The finder apparatus according to claim 5, an optical system that forms an image of an imaging target and has a function of changing magnification, an imaging unit that acquires an image of the imaging target formed by the optical system, A predetermined reference object whose position is unchanged with respect to the optical system, a conversion optical system that converts a reference light beam emitted from the reference object into a light beam equivalent to a light beam emitted from infinity, and the converted reference light beam for the imaging target A light projecting unit having an integrated optical system that integrates an imaging light beam incident on the optical system from the optical system, a detection unit that detects an image of the reference object formed by the optical system, and a detection unit And a reference mark superimposing unit that superimposes a reference mark on the image acquired by the imaging unit in accordance with the image of the reference object.
[0010]
The finder device according to claim 6 is the finder device according to claim 5, wherein the reference object emits the reference light beam indicating at least one point in the field of view of the optical system, and the reference mark overlapping portion is The optical axis mark indicating the position of the optical axis of the optical system is superimposed as the reference mark.
The finder device according to claim 7 is the finder device according to any one of claim 5 or claim 6, wherein the reference object indicates at least a line segment in a predetermined direction within the field of view of the optical system. A reference light beam is emitted, and the reference mark superimposing unit superimposes a division angle scale indicating an expected angle of an object as the reference mark.
[0011]
The finder device according to claim 8 is the finder device according to any one of claims 5 to 7, wherein the reference object is a mask on which a predetermined pattern is formed, and the light projecting unit is And a light source for illuminating the mask. The finder device according to claim 9 is the finder device according to any one of claims 5 to 8, wherein a light source of the light projecting unit is set to a predetermined wavelength range, and the detection unit is A dichroic mirror that is inserted between the optical system and the imaging unit and separates the reference beam from the imaging beam, and an optical sensor that detects an image of a reference object formed by the separated reference beam. It is characterized by.
[0012]
The finder device according to claim 10 is the finder device according to any one of claims 5 to 8, wherein the light projecting unit includes a polarization unit that adjusts a polarization direction of the reference light beam, The detection unit is inserted between the optical system and the imaging unit and detects a polarization beam splitter that separates the reference light beam from the imaging light beam, and an image of a reference object formed by the separated reference light beam. And an optical sensor.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
A first embodiment of the present invention will be described with reference to FIG. 1, FIG. 2, and FIG.
FIG. 1 is a configuration diagram of a finder apparatus according to the present embodiment.
[0014]
The viewfinder device includes a lens (hereinafter referred to as a zoom lens) 10 having a zooming function, an imaging camera 11, an arithmetic control circuit 12, a display unit 17 such as a monitor, and a light projecting unit 1.
The light projecting unit 1 is fixed to the lens barrel of the zoom lens 10. Reference numeral 18 in FIG. 1 denotes a mirror that guides external light in the direction of the zoom lens 10 (this is provided if necessary and is not essential).
[0015]
The zoom lens 10 forms an image of the light flux from the external target on the image sensor 11 a of the image camera 11.
Further, the zoom lens 10 is provided with a cam mechanism (not shown) that moves a part of the lens group in the optical axis direction, and the user directly or the user is not connected to the arithmetic control circuit 12. When the mechanism is appropriately driven via the illustrated motor, the magnification is changed between 1 and 20 times, for example.
[0016]
The imaging camera 11 captures an external target image by the zoom lens 10 and sequentially outputs the acquired signals to the arithmetic control circuit 12.
The arithmetic control circuit 12 includes a CPU 12a, a memory 12b (used for processing of the CPU 12a), a signal processing unit 12c, a frame memory 12d, and the like.
A signal input from the imaging camera 11 to the arithmetic control circuit 12 is subjected to predetermined signal processing in the signal processing unit 12c under the instruction of the CPU 12a, and then sequentially output to the display unit 17 via the frame memory 12d. . Therefore, as shown in the lower part of FIG. 1, a live image of an external target captured by the zoom lens 10 is displayed on the display unit 17.
[0017]
Here, the light projecting unit 1 described above is provided in the finder device of the present embodiment so that the arithmetic control circuit 12 can recognize the state of the zoom lens 10 (in particular, the position of the optical axis in the present embodiment). It is.
The light projecting unit 1 is converted into a mask 13 as a reference object, a light source unit 14 that illuminates the mask 13, a collimating lens 15 that converts a reference light beam emitted from the mask 13 into a light beam equivalent to a light beam emitted from infinity. A half mirror 16 is provided as an integrated optical system that integrates the reference light flux into the imaging light flux incident on the zoom lens 10 from the external target.
[0018]
In order to indicate the position of the optical axis, the opening pattern of the mask 13 is, for example, a circular minute arranged at the optical axis position (coordinates (0, 0) on the mask 13) as shown in the enlarged upper part of FIG. It consists of holes (pinholes) (hereinafter described as an opening pattern consisting of these microholes).
The arrangement position of the mask 13 is adjusted (aligned) in advance so that the center of the minute hole is surely aligned with the optical axis of the zoom lens 10.
[0019]
The light source unit 14 uniformly illuminates at least a portion of the mask 13 where the opening pattern is formed.
Here, the imaging light flux incident on the zoom lens 10 from the external target is a parallel light flux that is emitted from a sufficiently far distance (a position that can be regarded as infinity).
Further, the reference light beam incident on the zoom lens 10 from the mask 13 is also a parallel light beam due to the action of the collimating lens 15.
[0020]
Therefore, the apparent position of the mask 13 (apparent position with reference to the image sensor 11a) is substantially the same as the external target.
According to the light projecting unit 1 described above, an image of a minute hole (hereinafter referred to as a “point image”) of the mask 13 is formed at a position corresponding to the optical axis on the external target image.
[0021]
FIG. 2 is a diagram for explaining the display processing of the crosshairs by the CPU 12a in the arithmetic control circuit 12.
In addition to the process of displaying a live image as described above, the CPU 12a in the arithmetic control circuit 12 corresponds to a crosshair (corresponding to the “optical axis mark” in the claims) in order to cope with a change in the state of the zoom lens 10. .) Display processing.
[0022]
The crosshair display processing is performed periodically according to a user instruction, every time a specific operation (for example, driving of the zoom lens 10) in the finder apparatus is performed, or when the power source is turned on. It is executed every time it is input. Incidentally, when the zoom lens 10 is driven, it is expected that a change in the state of the zoom lens 10 will be large. Therefore, it is preferable that the zoom lens 10 is executed at least once immediately after the zoom lens 10 is driven.
[0023]
First, among signals sequentially input from the imaging camera 11, a signal for at least one frame (that is, one image) (FIG. 2A) is referenced, and a point image (FIG. 2 (FIG. 2)) is referred to. Only b)) is extracted.
Here, if the power of the light source unit 14 is set to be sufficiently large, the brightness of the point image can be made sufficiently higher than the brightness of the image of the external target. A point image is easily extracted simply by extracting from the data.
[0024]
When the external target is bright and the luminance difference from the point image can be small, as shown in FIG. 3, intermittent driving (at least once) in which the light source unit 14 is synchronized with the image sensor 11a within a short period of time. Is turned on / off), and a point image is obtained by referring to both the lighted image (FIG. 3A) and the lighted image (FIG. 3A ′), and taking the difference between the two images. The image (FIG. 3B) may be acquired.
[0025]
Next, the center coordinates (X, Y) of the point image in the image are obtained from the image of the point image (FIG. 3B).
The center coordinates of the point image can be obtained, for example, by obtaining the luminance centroid of each pixel of the point image data (the average position weighted by the luminance of each pixel at each position). Alternatively, by providing a higher threshold value close to the maximum brightness of the point image, only the relatively bright area of the point image may be detected, and the coordinates of the center of the area may be regarded as the center coordinates of the point image. Note that various known methods such as edge detection can be applied to obtain the center coordinates of the point image.
[0026]
Next, in accordance with the center coordinates (X, Y) of the point image, data of an image to be superimposed on the live image (hereinafter referred to as “superimposition image”, FIG. 2C) is created.
The superimposing image is an image of a reference mark such as a crosshair or a circle indicating the position of the optical axis of the zoom lens 10 (hereinafter referred to as a crosshair with a division scale).
In the present embodiment, the coordinates of the center of the crosshair are made to coincide with the center coordinates (X, Y) of the point image.
[0027]
For example, when the center coordinate (X, Y) of the point image is (0, 0), the center coordinate of the crosshair is also (0, 0) as shown in the lower part of FIG. If (X, Y) is deviated from (0, 0) as shown in FIG. 2 (b), the center coordinates of the crosshair are also deviated from (0, 0) by the same amount as shown in FIG. 2 (c). It is.
In the present embodiment, the dividing line scale of the crosshairs is set at a predetermined interval, and the user determines what expected angle corresponds to one scale of the dividing line scale according to the lens magnification.
[0028]
The lens magnification is preferably recognized by the CPU 12a from the arrangement state of the lens in the zoom lens 10 of FIG. 1, in which case an image showing the lens magnification (magnification display, for example, “× 20” or the like) It is added to this superimposing image.
When the superimposition image (FIG. 2C) is created in this way, the CPU 12a superimposes the superimposition image on the live image of the external target on the frame memory 12d.
[0029]
The superimposition image may be generated by the CPU 12a on the frame memory 12d. However, if the superimposition image is simple, such as a simple crosshair or a dividing angle memory, the crosshair to be superimposed is calculated as an arithmetic circuit. 12 can also be generated using a counter or a decoder. In this case, the frame memory 12d can be omitted.
[0030]
As a result, a crosshair (preferably, a magnification display) is added to the live image of the external target on the display unit 17 (FIG. 2 (d)). The cross line display processing by the CPU 12a is as described above.
Here, as described above, the center of the cross line coincides with the center of the point image generated by the light projecting unit 1, but the reference light beam forming the point image is actually transmitted through the zoom lens 10. Therefore, when the actual position of the optical axis is shifted due to backlash or environmental change, the position of the point image is similarly shifted.
[0031]
Therefore, the crosshairs accurately indicate the optical axis of the zoom lens 10 even if the zoom lens 10 changes its state.
In the finder device of the present embodiment, if a point image is displayed on the display unit 17, it is difficult to see a part of the external target, but the light source unit 14 in the cross-line display processing is difficult to see. It is preferable that the lighting time be as short as possible (preferably only during the period in which the image shown in FIG. 2A is acquired).
[0032]
In the present embodiment, the magnification (such as “× 10” and “× 20”) of the zoom lens 10 is displayed together with the crosshairs. However, the interval between the divisional scales of the crosshairs is acquired from the zoom lens 10. You may expand / contract according to magnification. In that case, it is not necessary for the user to replace the unit of the division scale.
[Second Embodiment]
A second embodiment of the present invention will be described with reference to FIGS. Here, only differences from the first embodiment will be described.
[0033]
FIG. 4 is a configuration diagram of the finder device of the present embodiment.
The difference from the viewfinder device of the first embodiment is that not only the optical axis of the zoom lens 10 but also the expected angle of the object can be displayed accurately.
Accordingly, a light projecting unit 2 is provided instead of the light projecting unit 1, and an arithmetic control circuit 22 is provided instead of the arithmetic control circuit 12.
[0034]
The light projecting unit 2 is provided with a mask 23 instead of the mask 13 in the light projecting unit 1.
The opening pattern of the mask 23 indicates the position of the optical axis (on the mask 23), for example, as shown enlarged in the upper part of FIG. 4 in order to show the position of the optical axis of the zoom lens 10 and the reference of the prospective angle (that is, the reference of magnification). The first microholes arranged at the coordinates (0,0)) and the second microholes arranged at a position different from the optical axis (coordinates (0, y1) on the mask 23). Hereinafter, the description will be made assuming that the first microhole and the second microhole are included.
[0035]
The distance between the first minute hole and the second minute hole is the reference for the prospective angle (reference for magnification).
The arrangement position of the mask 23 is adjusted (aligned) in advance so that the center of the first minute hole is surely aligned with the optical axis of the zoom lens 10.
The light source unit 14 uniformly illuminates at least a portion of the mask 23 where the opening pattern is formed. In this embodiment, since it is necessary to illuminate a plurality of (here, two) micro holes, a plurality of (for example, two) light sources may be prepared.
[0036]
According to the light projecting unit 2 described above, the image of the mask 23 formed on the image sensor 11a is the first microhole image and the second microhole image (hereinafter, “first point images”, respectively). "Second point image").
The arithmetic control circuit 22 has the same configuration as the arithmetic control circuit 12, but a part of the cross-line display processing performed by the CPU 22 a and the memory 22 b provided therein is provided in the arithmetic control circuit 12. This is different from what is performed by the CPU 12a and the memory 12b. Hereinafter, the different points will be described.
[0037]
FIG. 5 is a diagram for explaining cross-hair display processing by the CPU 22a in the arithmetic control circuit 22.
The CPU 22a of the present embodiment extracts the first point image and the second point image (FIG. 5B) from one image (FIG. 5A). The extraction method may be the same as in the first embodiment.
[0038]
From the image (FIG. 5B), the center coordinates (X1, Y1) of the first point image and the center coordinates (X2, Y2) of the second point image in the image are obtained. It is done. The extraction method may be the same as in the first embodiment.
Also in the present embodiment, the coordinates of the center of the cross line (FIG. 5C) to be drawn on the superimposed image match the center coordinates (X1, Y1) of the first point image.
[0039]
Further, in the present embodiment, the interval between the divisional scales (one scale) given to the crosshairs always indicates the same prospective angle. That is, the interval of the division scale is set according to the magnification actually set in the zoom lens 10.
First, the magnification actually set in the zoom lens 10 can be specified by the interval between the first point image and the second point image.
[0040]
Therefore, in the cross-hair display process of the present embodiment, the distance b = | Y2-Y1 | between the first point image and the second point image is obtained.
If the distance between the first point image and the second point image when the zoom lens is set to the same magnification is a, the actual magnification of the current zoom lens 10 is (b / a). It is.
[0041]
Therefore, if the interval between the divisional scales to be displayed when the zoom lens 10 is set to the same magnification is d, the interval between the divisional scales to be displayed is d × (b / a )
Therefore, in the present embodiment, the distance a between the actual first point image and the second point image when the zoom lens 10 is previously set to a predetermined magnification (hereinafter referred to as equal magnification for simplicity). , And information indicating the interval d of the fractional scale to be displayed at that time is stored in the memory 22b (more precisely, the memory 22b stores at least the relationship between a and b (d / A).
[0042]
Then, the CPU 22a in the cross-hair display processing determines the interval of the dividing line scale of the cross-hair to be drawn as the superimposition image according to the obtained interval b and the content stored in the memory 22b by b × (d / Set to a) (FIG. 5C).
As a result, the cross line (FIG. 2D) added to the live image of the external target on the display unit 17 coincides with the actual optical axis of the zoom lens 10 and is added to the center. The angle scale accurately indicates the actual prospective angle.
[0043]
In addition, in this embodiment, since the division | segmentation scale interval expands / contracts automatically according to the magnification of the zoom lens 10, there also exists an advantage that a user does not need to read the unit of a division | segmentation division scale.
In this embodiment, since the actual magnification of the zoom lens 10 is obtained by (b / a), the magnification may be displayed together with a cross line such as “× 20” and “× 16”.
[0044]
In this embodiment, only the arrangement position of the crosshairs and the interval between the divisional scales of the crosshairs are changed, and the arrangement angle of the crosshairs is not changed at all. When there is a possibility that the zoom lens 10 and the light projecting unit 2 may rotate around the optical axis with respect to the image sensor 11a due to the above, etc., the crosshairs according to the arrangement angle of the line segment connecting the two point images described above May be set.
[0045]
[Supplement to the first embodiment and the second embodiment]
In the first embodiment and the second embodiment, not only the above-described mask but also other masks having different opening patterns can be applied.
FIG. 6 is a view showing variations of the mask applied to the finder apparatus of the first embodiment and the second embodiment (and third and fourth embodiments described later).
[0046]
The opening pattern of the mask according to the first embodiment only needs to indicate at least one coordinate because it only needs to indicate at least the optical axis of the zoom lens 10.
The opening pattern may be a cross-shaped hole instead of a circular minute hole, but the most preferred is a minute hole. This is because if the hole is a minute hole, the luminance of the image can be made relatively high even if a light source having the same power is used.
[0047]
In order to simplify the calculation, it is most preferable to arrange the micropores at the coordinates (0, 0) of the optical axis. However, as long as the relationship with the coordinate (0, 0) of the optical axis is known, it may be arranged at another coordinate.
The masks shown in FIGS. 6A, 6B, and 6C are applicable to the first embodiment because at least one minute hole is arranged at the coordinate (0, 0) of the optical axis.
[0048]
Further, in each of the masks shown in FIGS. 6D, 6E, and 6F, micropores are formed at positions different from the coordinates (0, 0) of the optical axis. In FIG. The two micro holes represent the coordinates (0, 0) of the optical axis depending on the center position of each other. In FIG. 6E, the two micro holes on the left and right represent the coordinates (0, 0) of the optical axis depending on the center positions of each other. In FIG. 6D, the upper and lower two microholes or the left and right two microholes represent the coordinates (0, 0) of the optical axis according to the center positions of each other. It is applicable to the embodiment.
[0049]
On the other hand, the opening pattern of the second embodiment needs to indicate a certain line segment (that is, two coordinates) because it is necessary to indicate the reference of the prospective angle in addition to the coordinates of the optical axis.
The masks shown in FIGS. 6 (a) and 6 (d) are applicable to the second embodiment because the two upper and lower microholes indicate line segments (note that the mask shown in FIG. 6 (a) is not shown in the figure). This is the same as the mask shown in FIG. The masks shown in FIGS. 6B and 6E are applicable to the second embodiment because the two micro holes on the left and right indicate line segments.
[0050]
Also, the masks shown in FIGS. 6C and 6F are applicable to the second embodiment because they show two vertical and left and right line segments, respectively.
If the mask shown in FIG. 6C or FIG. 6F is used in the second embodiment, the horizontal magnification and the vertical magnification of the zoom lens 10 can be obtained independently. The interval between the divisional scales and the interval between the horizontal divisional scales may be set individually.
[0051]
In addition, as described above, a mask having a small opening area (such as a mask in which microholes are formed) is preferable because it is easy to increase the luminance of the image, but a transparent substrate is preferable. A mask having many openings such as a pattern drawn thereon is also applicable to the present invention.
In the second embodiment, if the mask opening or the light-shielding pattern is made up of a plurality of marks arranged at different positions of the object height, the magnification unevenness in the image height direction of the zoom lens 10 can be obtained. The interval between the line division scales may be individually set according to the position of the image.
[0052]
[Third Embodiment]
A third embodiment of the present invention will be described with reference to FIG. Here, only differences from the first embodiment will be described.
FIG. 7 is a configuration diagram of the finder device of the present embodiment.
In the finder apparatus of the first embodiment, the image sensor 11a that detects an image of an external target is also used as a point image detector. However, in the finder apparatus of this embodiment, the point image detector 30 is the imaging camera 11. It is provided separately.
[0053]
Since this detector 30 utilizes the difference in light characteristics depending on the wavelength, the light source unit 34 of the light projecting unit 3 has a predetermined wavelength range. This wavelength range is selected to be different from the wavelength range (hereinafter referred to as the visible light range) to be detected as the external target image (hereinafter referred to as the near infrared range).
The detector 30 is inserted between the zoom lens 10 and the imaging camera 11, and the imaging light beam (here, the reference light beam (made of near-infrared light here) from the mask 13 is emitted from the external target. And the dichroic mirror 37 that separates the light beam and the optical sensor 39 that detects the image of the mask 13 formed by the separated reference light beam.
[0054]
As the optical sensor 39, an image sensor that can detect an image of the opening pattern of the mask 13 with sufficient accuracy is used. Incidentally, when only one minute hole of the mask 13 is provided and only one point image needs to be detected, a semiconductor position detector such as PSD may be used as the optical sensor 39.
As described above, if the detector 30 is provided separately from the imaging camera 11, the arithmetic control circuit 32 (the CPU 32 a and the memory 32 b in the arithmetic control circuit 32) of the present embodiment instantly displays a point image from the output of the detector 30. 2 can be recognized, the extraction process (point image image extraction process) as shown in FIGS. 2A and 2B can be omitted.
[0055]
In addition, since the detector 30 is provided separately from the imaging camera 11, the external target image displayed on the display unit 17 does not overlap the point image, and the visual field is improved.
According to the present embodiment, a good field of view is always maintained even during the execution of the cross-hair display process (see FIG. 2), so that the state of the zoom lens 10 changes when the finder device is mounted on a moving body. In the case of frequent occurrence, it is preferable to apply the present embodiment and increase the execution frequency of the crosshair display processing.
[0056]
[Fourth Embodiment]
A fourth embodiment of the present invention will be described with reference to FIG. Here, only differences from the first embodiment and the third embodiment will be described.
FIG. 8 is a configuration diagram of the finder device of the present embodiment.
In the finder apparatus of the present embodiment as well, the detector 40 is provided separately from the imaging camera 11 as in the finder apparatus of the third embodiment.
[0057]
However, since this detector 40 uses the difference in the light characteristics depending on the polarization direction, a polarizing plate 48 for adjusting the polarization direction of the reference light beam emitted from the mask 13 at the subsequent stage of the light source 14 of the light projecting unit 4. Is inserted.
[0058]
The detector 40 is inserted between the zoom lens 10 and the imaging camera 11 and separates the reference light beam (adjusted in a predetermined polarization direction) from the mask 13 from the imaging light beam emitted from the external target. It comprises a polarization beam splitter 47 and an optical sensor 49 that detects an image of the mask 13 formed by the separated reference light beam.
As the optical sensor 49, an image sensor that can detect an image of the opening pattern of the mask 13 with sufficient accuracy is used. Incidentally, when only one minute hole of the mask 13 is provided and only one point image needs to be detected, a semiconductor position detector such as PSD may be used as the optical sensor 49.
[0059]
As described above, if the detector 40 is provided separately from the imaging camera 11, the center coordinates of the point image are immediately recognized from the output of the detector 40 as in the third embodiment. The extraction process (point image image extraction process) as shown in (b) can be omitted, and the external field target image displayed on the display unit 17 does not overlap the point image, so the field of view is improved. .
[0060]
According to the present embodiment, a good field of view is always maintained even during the execution of the cross-hair display process (see FIG. 2), so that the state of the zoom lens 10 changes when the finder device is mounted on a moving body. In the case of frequent occurrence, it is preferable to apply the present embodiment and increase the execution frequency of the crosshair display processing.
[Others]
In addition, the finder apparatus of each said embodiment can be used as a sighting device mounted in various apparatuses. Since it is strong against vibration and temperature change as described above, it is particularly suitable as a sighting device mounted on a moving body.
[0061]
Further, in each of the above embodiments, if the reference mark superimposed on the live image indicates the optical axis (or the prospective angle), the above-described cross line (or the cross line provided with a division angle scale) It may have any shape without being limited to. The shape is preferably selected as appropriate according to the type of equipment on which the finder device is mounted.
[0062]
【The invention's effect】
As described above, according to the present invention, it is possible to realize a finder device that can accurately display a reference mark such as a crosshair or a crosshair with a division scale, regardless of a change in the state of the optical system.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a viewfinder device according to a first embodiment.
FIG. 2 is a diagram for explaining cross-hair display processing by a CPU 12a in an arithmetic control circuit 12. FIG.
FIG. 3 is a diagram for explaining another method of extracting a point image.
FIG. 4 is a configuration diagram of a finder device according to a second embodiment.
FIG. 5 is a diagram illustrating a crosshair display process performed by a CPU 22a in the arithmetic control circuit 22.
FIG. 6 is a diagram showing variations of a mask applied to the finder apparatus of the first embodiment, the second embodiment, the third embodiment, and the fourth embodiment.
FIG. 7 is a configuration diagram of a viewfinder device according to a third embodiment.
FIG. 8 is a configuration diagram of a viewfinder device according to a fourth embodiment.
[Explanation of symbols]
1 Light emitter
10 Zoom lens
11 Imaging camera
11a Image sensor
12, 22, 32 arithmetic control circuit
12a, 22a, 32a CPU
12b, 22b, 32b memory
12d frame memory
12c Signal processor
13,23 mask
14, 34 Light source
15 Collimating lens
16 half mirror
18 Mirror
17 Display
30, 40 detector
37 dichroic mirror
39, 49 Light sensor
47 Polarizing Beam Splitter

Claims (10)

An optical system that forms an image of the object to be imaged and has a zooming function;
An imaging unit that acquires an image of an imaging target imaged by the optical system;
A predetermined reference object whose position is unchanged with respect to the optical system, a conversion optical system that converts a reference light beam emitted from the reference object into a light beam equivalent to a light beam emitted from infinity, and the image of the converted reference light beam A light projecting unit having an integrated optical system integrated with an imaging light beam incident on the optical system from a target;
A finder apparatus comprising: a reference mark superimposing unit that superimposes a reference mark on the image acquired by the imaging unit in accordance with an image of the reference object detected by the imaging unit. The finder device according to claim 1,
The reference material is
Emitting the reference luminous flux indicating at least one point in the field of view of the optical system;
The reference mark superimposing unit is
A viewfinder device, wherein an optical axis mark indicating the position of the optical axis of the optical system is superimposed as the reference mark. In the finder apparatus as described in any one of Claim 1 or Claim 2,
The reference material is
Emitting at least the reference luminous flux indicating a line segment in a predetermined direction within the field of view of the optical system;
The reference mark superimposing unit is
A finder apparatus that superimposes a division scale indicating an expected angle of an object as the reference mark. In the finder apparatus as described in any one of Claims 1-3,
The reference object is a mask on which a predetermined pattern is formed, and the light projecting unit has a light source for illuminating the mask. An optical system that forms an image of the object to be imaged and has a zooming function;
An imaging unit that acquires an image of an imaging target imaged by the optical system;
A predetermined reference object whose position is unchanged with respect to the optical system, a conversion optical system that converts a reference light beam emitted from the reference object into a light beam equivalent to a light beam emitted from infinity, and the image of the converted reference light beam A light projecting unit having an integrated optical system integrated with an imaging light beam incident on the optical system from a target;
A detection unit for detecting an image of the reference object formed by the optical system;
A finder apparatus comprising: a reference mark superimposing unit that superimposes a reference mark on the image acquired by the imaging unit according to an image of the reference object detected by the detection unit. The finder apparatus according to claim 5,
The reference material is
Emitting the reference luminous flux indicating at least one point in the field of view of the optical system;
The reference mark superimposing unit is
A viewfinder device, wherein an optical axis mark indicating the position of the optical axis of the optical system is superimposed as the reference mark. In the finder apparatus as described in any one of Claim 5 or Claim 6,
The reference material is
Emitting at least the reference luminous flux indicating a line segment in a predetermined direction within the field of view of the optical system;
The reference mark superimposing unit is
A finder apparatus that superimposes a division scale indicating an expected angle of an object as the reference mark. In the finder apparatus as described in any one of Claims 5-7,
The reference object is a mask on which a predetermined pattern is formed, and the light projecting unit has a light source for illuminating the mask. In the finder apparatus as described in any one of Claims 5-8,
The light source of the light projecting unit is
Set to a predetermined wavelength range,
The detector is
A dichroic mirror that is inserted between the optical system and the imaging unit and separates the reference beam from the imaging beam, and an optical sensor that detects an image of a reference object formed by the separated reference beam. Finder device characterized by. In the finder apparatus as described in any one of Claims 5-8,
The light projecting unit is
Polarization means for adjusting the polarization direction of the reference beam;
The detector is
A polarization beam splitter that is inserted between the optical system and the imaging unit and separates the reference beam from the imaging beam, and an optical sensor that detects an image of a reference object formed by the separated reference beam. A finder device characterized by that.

Images