JPS61283844A - Mirror position controller for projection characteristic measuring apparatus of lens - Google Patents

Abstract

PURPOSE:To enable highly accurate control of a mirror with a simplified construction of a controller, by arranging a light source near a lens to be measured while a light receiver is mounted on a projector to detect the light source through the mirror. CONSTITUTION:Light projected from a collimator 4 as projector is reflected with a mirror 5 to irradiate a lens at a colatitude theta. In this case, when the light is projected at a specified lens position 1, a light receiver 10 mounted on the side of the collimator 4 detects a light source 11 set near the lens through the mirror. When the position along the moving shaft of the mirror 5 is not proper, the light from the collimator 4 is projected at the position deviated from that as specified, as indicated by the alternate long and short dash line and hence, the light receiver 10 fails to detect light of the light source 11. The position of the mirror 5 is controlled by detecting the propriety of the position thereof on the basis of the signal from the light receiver 10.

Description

[Detailed Description of the Invention] [Summary] This is a position control device for a projection characteristic measuring device of a lens, which detects a light source provided near the lens through a mirror with a light receiver provided in a projector, and determines the mirror position. The control made the device simple and accurate.

[Industrial Field of Application] This invention relates to a lens projection characteristic measuring device for measuring the light emission characteristics of a lens, particularly a lens projection characteristic measuring device of a type in which light from a projector is reflected by a chain and then incident on the lens. Regarding a control device.

[Prior Art] In recent years, a technology has been used in which a camera device including a lens and an ms element performs environment recognition using an image input means. As described above, in the technical field, it is not possible to accurately recognize the environment without knowing the projection characteristics of the lens.

This is to know at which position on the image plane Ii the lens forms an image of light incident on the lens from a certain direction, and based on this result, the direction of incidence of the light is recognized from the point where the image is formed.

As shown in FIG. 5, a lens projection characteristic measuring device for measuring the lens projection characteristics is such that a television camera 2 with a lens 1 attached thereto is placed on a rotary table 3 and rotated about the optical axis A. The collimator 4 is fixed obliquely to the optical axis A of the lens 1 as a projector that irradiates parallel light, and the irradiation direction is set above the parallel light. A moving shaft 6 is provided parallel to #!, and a moving member 7 that moves along the moving shaft 6 is connected to the moving shaft 6. t5 is mounted so as to be located in parallel light, and the mirror 5 can be tilted with respect to the movable member 7 with the tilt axis being perpendicular to the optical axis. Then, the position on the imaging surface of the television camera 2 where the light incident on the lens 1 is imaged is measured, and the incident direction of the light and the image-forming position Il! The correspondence with the position of the IfIA surface can be known.

Here, in order to automatically measure the projection characteristics of this lens, the inclination of the mirror 5 and the angle of the mirror 5 are adjusted as shown in FIG.
The movement of the TV camera 2 and the rotation of the TV camera 2 are controlled by motors 20 and 21, respectively.
．． At the same time, the tilt angle of the mirror, the mirror position, and the rotation angle of the camera are measured by measuring devices 23, 24, and 25, respectively, and these measurement values and the imaging position of the light on the imaging plane of the television camera 2 are measured by the measuring device 26. Each motor is controlled by the control device 27 based on the value measured in the above.

When automatically measuring the projection characteristics of this lens, the inclination angle of the mirror 5 is first set.

If the inclination angle of gI5 is determined, the movement of the mirror 5 in the direction of the movement axis 6 is parallel to the parallel light, so the total latitude θ of the incident light to the lens 1 is uniquely determined, and the The azimuth angle can be uniquely determined by the rotation of the television camera 2. However, even if the total latitude and azimuth angle of the incident light are determined, if the incident light does not properly enter the surface of the lens 1 (for example, the state shown in Figure 5), the incident light will not form an image on the imaging surface, or Due to insufficient light intensity, accurate lens projection characteristics cannot be measured. Therefore, it is necessary to control the position of the mirror 5 in the direction of the movement axis 6.

Conventionally, as a control device for the direction of the movement axis 6 of the mirror 5, for example, the position of a predetermined mirror 5 on the movement axis 6 at the inclination angle of the mirror 5 is calculated in advance, and this value is input into the control device 27. On the other hand, as shown in FIG.
Some devices control the position of 15 by providing a position sensor 9 that detects the position of .

Another device for controlling the position of the mirror 5, as shown in FIG. 6, is one that directly detects whether light is focused on the imaging surface using the ms plane image of the television camera 2. be.

In FIG. 6, φ does not indicate the field of view of the lens 1, and schematically shows the image of the m image plane in the case shown in FIG. In the figure, the light 10 from the collimator 4 is insufficiently focused on the first surface through the mirror 5. This light is detected by the measuring device, and #R4 is moved in the optical axis direction to obtain sufficient light. (indicated by a in the figure) to control the light 10 to be centered on the mirror 5.

[Problems to be Solved by the Invention] By the way, in the first mirror control device described above, the position corresponding to the angle [5] must be calculated in advance, which is complicated, and it is difficult to move the mirror. A position sensor must be provided on the member, which complicates the device.

In addition, in the second device described above, if the measurement lens has a wide field of view, the size of the image on the imaging surface of the mirror, light, etc. will be extremely small, making it difficult to perform the above-mentioned control accurately. It will be difficult to do.

[Means for Solving the Problems] The present invention solves the above-mentioned problems, simplifies the structure of a mirror position control device in a lens projection characteristic measuring device, and accurately controls the mirror position control device. In order to achieve this, we need a projector that is tilted with respect to the lens optical axis and emits light toward a point on the upward extension of the lens optical axis, and a projector that moves along the direction of the light and is mounted at an angle. In a projection characteristic measuring device for a lens, which consists of a mirror that is variable and reflects the light toward the lens, and a rotary table that rotates the lens, a light source is placed near the lens to be measured, and the light source is connected to the projector. It is now detected through the mirror and controlled to the appropriate position of the mirror.

[Function] As shown in FIGS. 1 and 2, the light emitted by the collimator 4, which is a projector, is reflected by #Ji5 and is emitted onto the lens 1 at all latitudes θ. In this case, when the predetermined lens position 1 is irradiated, the light receiver 10 attached to the side of the collimator 4 detects the light source 11 provided near the lens via the mirror 5. Also! If the position of the i5 along the movement axis is inappropriate, the light from the collimator 4 is irradiated onto a position away from the predetermined position of the lens 1 (indicated by a dashed line in FIG. does not detect the light from the light source 11. Based on the signal from the light receiver 10, the suitability of the position of the mirror is detected and the position of the mirror 5 is controlled.

[Example] Hereinafter, an example of a mirror position control device in a lens projection characteristic measuring device according to the present invention will be described.

FIG. 3 shows an embodiment of a mirror position control device in a lens projection characteristic measuring device according to the present invention. In this embodiment, the collimator 4, which is a light projector, is fixed to the substrate 12 using a stand 13 so as to emit parallel light upward to the lens 1 using, for example, a reference crosshair. Further, a television camera 2 with a lens 1 attached thereto is attached to a substrate 12 via a rotary table 3. A moving shaft 6 on which the mirror 5 is movably attached via a moving member 7 is fixed on a base 12 using two stands 14. Note that the positional relationship of these members can be changed depending on the size of the lens 1, television camera 2, etc.

A light source 11 is attached to one stand 14 supporting the moving shaft 6 via an arm 15.
1 is also provided near the lens 1. In addition, a light source 1 is located on the opposite side of the collimator 4 between the light source 11 and the lens 1.
A photoreceiver 10 is provided for detecting 1 through a mirror 5. This light receiver 10 is connected to a control device M27, and a motor driver 28 is connected to this control device to control the mirror moving motor 21. This -IIll is carried out according to the flowchart shown in FIG.

Therefore, the procedure for measuring the projection characteristics of a lens according to this embodiment is as follows: First, in order to determine the total latitude θ of the incident light from the collimator 4 to the lens 1, the mirror tilting motor 20 is activated to tilt the mirror 1115 to a predetermined angle. .

At this time, the total latitude θ is uniquely determined by the inclination of 114, but the irradiation light is not necessarily irradiated onto a predetermined position of the lens 1. Therefore, adjustment is performed by moving the mirror 4 along the movement axis 6. That is, first, the mirror 5 is set to the initial position, and the mirror 5 is moved until the light receiver 10 detects the light source 11 near the lens 1, and the light receiver 10 detects the light source 11 near the lens 1 via the mirror 5. Make it stop at that position. As a result, the mirror 5 reflects the light from the collimator 4 and makes the light rays enter the lens 1 at all latitudes θ.

In this state, the rotary table 3 is rotated to measure the azimuth angle of the light incident on the lens 1 while changing it between 0 and 2π.

By performing this procedure for the necessary extra line a value, it is possible to measure the projection characteristics of the lens for all necessary latitudes and azimuths.

Therefore, according to this embodiment, there is no need to provide a position + mm meter or the like on the movable part of the mirror position control device in the lens projection characteristic measuring device, and the structure can be simplified, and accurate mirror position measurement can be achieved. can be done.

[Effects of the Invention] As explained above, according to the present invention, since the mirror position control device in the lens projection characteristic measuring device is configured as described above, there is no need to provide a measuring device or the like on the movable part. Since the detection is carried out optically, the structure of the control I device can be simplified, and the mirror can be controlled with high precision.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a mirror position control device in a lens projection characteristic measuring device according to the present invention, FIG. 2 is a front view of the measuring device shown in FIG. 1, and FIG. 3 is a side view showing an embodiment of the present invention. 4 is a flowchart of mirror position control used in the present invention, FIG. 5 is a side view showing an example of a conventional control device, and FIG.
This figure shows another example of the conventional control device, and FIG. 7 is a block diagram showing the control system of the conventional control device and the control device of the present invention. 1...Lens 2...TV camera 3...
・Rotary table 4...Collimator (emitter) 5...Mirror 6...Movement axis 10...Receiver 11...Light source Patent applicant Director of the Agency of Industrial Science and Technology Todoroki Tatsufushichi θa no Torajet Kari 1000 T figure 3/4 figure
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Claims (1)

[Claims] A projector that is tilted with respect to the optical axis of the lens and emits light toward a point on the upward extension of the optical axis of the lens, and a projector that moves along the irradiation direction of the light and whose mounting angle is variable to reflect the light toward the lens. In a projection characteristic measurement device for a lens, which consists of a mirror that rotates the lens, and a rotary table that rotates the lens, a light source is placed near the lens to be measured, and the projector detects this light source through the mirror and detects the light source of the mirror. A mirror position control device in a lens projection characteristic measuring device characterized by controlling the mirror position to an appropriate position.