JP3119081B2 - Color separation prism optical path length measurement device and color separation prism bonding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color separation prism optical path length measuring apparatus and a color separation prism bonding apparatus used in a three-plate camera system.

[0002]

2. Description of the Related Art In recent years, three-panel camera systems using three CCDs have increased in business cameras, and the performance thereof depends on how accurately the three CCDs are positioned and fixed. In addition, a structure in which the prism and the CCD are brought into close contact with each other and hardened with an adhesive has been developed as a structure that may be shifted during the fixing process and has a small shift. At this time, if the optical path lengths of the respective colors of the prism are different, the focus positions of the respective colors are shifted and the performance as a camera is not obtained. Therefore, it is necessary to evaluate whether or not the optical path length of each color of the color separation prism is accurately determined, and a highly accurate optical path length measuring device is desired. Further, there is a demand for an apparatus for producing a highly accurate color separation prism based on the measurement results.

A conventional method for measuring the optical path length of a color separation prism will be described below. FIG. 4 shows the configuration of a conventional optical path length measuring device. In FIG. 4, reference numeral 41 denotes a chart as a standard subject, and reference numeral 42 denotes a lens for forming an image of the chart. Reference numeral 43 denotes a color separation prism to be measured. 44a is the Rc of the color separation prism.
The microscope is arranged on the moving stage 45a in the h direction. Similarly, 44b and 44c are Gc
h, moving stage 45 with microscope arranged in Bch direction
b, 45c.

[0004] The operation of the optical path length measuring apparatus configured as described above will be described below. First, the chart image enters the color separation prism by the lens, and R,
It is separated into G and B colors and forms an image. The position at which the image is formed can be measured by moving the moving stage while looking at the microscope and adjusting the focus.

[0005]

However, in the above-described conventional optical path length measuring method, it is necessary to focus each of them, and it takes time, and the focusing always becomes a bottleneck of the depth of focus. It was difficult to measure with high accuracy.

An object of the present invention is to solve the above-mentioned conventional problems. An excellent optical path length measuring apparatus capable of measuring the optical path length of a color separating prism with high accuracy in a short time and a color separating prism using the present measuring apparatus. An object of the present invention is to provide a bonding device.

[0007]

According to the present invention, in order to achieve the above object, an optical path length measuring device for a color separation prism comprises a line type illuminating device and light generated from the line type illuminating device and passing through a slit. A lens unit for condensing light on the exit end of the color separation prism, and an optical axis of the lens unit.
The slit tilted back and forth, and the lens unit
A half mirror disposed on the front side , a color camera unit that captures reflected light from the emission end of the color separation prism via the half mirror, and an image operation processing unit that performs an operation process on an image signal of the color camera unit ; The mosquito
The distance between the imaging surface of the color camera and the half mirror is
Front so that it is equal to the distance between the
The color camera, the half mirror and the slit are arranged.
Is placed .

In addition, in addition to the above, the color separation prism bonding apparatus further includes a holder for holding a glass plate at the emission end of the prism via an adhesive, and a holder for holding the glass plate, and an optical axis of the prism. A moving stage for moving in the direction, an ultraviolet light source, and a light guide for guiding the ultraviolet light emitted from the ultraviolet light source to the glass plate.

[0009]

According to this structure, the light emitted from the slit is condensed by the lens unit, reflected at the exit end of each channel (Rch, Gch, Bch) of the color separation prism, passed again through the lens unit and guided to the color camera by the half mirror. I will Therefore, the image of the slit is projected on the color camera, but at this time, because the slit is tilted back and forth, the focused position on the color camera changes up and down due to the optical path length of the color separation prism. Become. Therefore, by calculating the focus position for each color by the image processing unit, the optical path length of the color separation prism can be measured with high accuracy in a short time.

Further, when a glass plate is arranged at the exit end of the prism via an adhesive, the optical path length to the glass plate can be measured accurately, and a holder for holding the glass plate is mounted on the moving stage based on the measured value. By irradiating the glass surface with ultraviolet light emitted from the ultraviolet light source using a light guide, the color separation prisms whose optical path lengths of the three colors have been adjusted with high precision can be bonded.

[0011]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a color separation prism optical path measuring and bonding apparatus according to an embodiment of the present invention. In FIG. 1, 1 is a line type illumination device, 2 is a slit inclined forward and backward with respect to the optical axis of the lens unit , and 3 is 4 with respect to the optical axis.
A half mirror inclined at 5 °, 4 is a lens unit, 5 is a color separation prism to be measured, and 6 is a glass plate at the focal position of the lens unit 4 at the emission end (5
r, 5g, 5b) or the rear surface of the glass plate. Reference numeral 7 denotes a color camera in which the color camera, the half mirror, and the slit are arranged such that the distance between the imaging surface and the half mirror is equal to the distance between the half mirror and the slit . Reference numeral 8 denotes an image processing unit that receives an image signal from the color camera. 9 is a glass holder for holding the glass plate 6, 10 is a moving stage for moving the glass plate 6 and the glass holder 9 based on the result of the image processing unit 8, 11 is a color separation prism 5 and the glass plate 6. Reference numeral 12 denotes an ultraviolet light source for irradiating UV light (ultraviolet light) for bonding the light source, and a light guide 12 for guiding the ultraviolet light to the rear surface of the glass plate.

The operation of the optical path length measuring device for a color separation prism configured as described above will be described with reference to FIGS. First, among the light emitted from the line-type illumination device 1 in FIG. Outgoing ends 5r, 5 of each channel
The light reflected from g, 5b or the glass plate 6 passes through the lens unit 4 again, is reflected by the half mirror 3, and is condensed on the imaging surface of the color camera 7. Hereinafter, the measurement principle of the color separation prism optical path length measuring device will be described. Here, FIG. 2A is a schematic view of an image of a slit captured by a color camera for explaining the measurement principle of the color separation prism optical path length measuring apparatus in the present embodiment, and FIG. 2B is a three-dimensional schematic view of a luminance distribution. Figure, (c)
Is a schematic diagram of a luminance distribution when out of focus, (d) is a schematic diagram of a sine function for obtaining a detection output, and (e) is a schematic diagram of a detection output waveform. On the imaging surface, as shown in FIG. 2A, the slit 2 is tilted, so that the image is focused only near the center, but before and after that, the image is out of focus. FIG. 2B shows this luminance distribution in a three-dimensional manner, and indicates that the luminance level is higher at the position where focus is achieved. For example, when the exit end of the color separation prism 5 or the position of the rear surface of the glass plate 6 is shifted from the reference position, as shown in FIG. Will be. If this displacement is measured with high accuracy, a highly accurate optical path length measuring device can be realized. Thus, by multiplying the luminance distribution of FIG. 2C by a sine function, for example, as shown in FIG. 2D, a kind of detection output waveform as shown in FIG. 2E can be obtained. This value is the deviation of the measured optical path length from the reference value, and the moving stage 10 is moved so that the value becomes zero.
By adhering the color separation prism 5 and the color separation prism 5, a color separation prism having an optical path length meeting the reference value can be formed.

FIG. 3 is a characteristic diagram of the amount of movement of the glass plate and the detection output according to the present embodiment. ± 4μ dispersion is ± 0.9μ
m, indicating that highly accurate measurement is possible.

As is apparent from the above, the color separation prism optical path length measuring and bonding apparatus according to the present embodiment has an excellent effect in that high-precision measurement can be performed at high speed.

As described above, according to the present embodiment, the line illuminator 1, the slit 2 inclined forward and backward with respect to the optical axis of the lens unit, and the slit 2 generated from the line illuminator 1 A lens unit 4 for condensing the light having passed therethrough at an output end of the color separation prism 5; a half mirror 3 disposed on the front surface of the lens unit 4; The color separation prism 5 can be measured with high accuracy and at high speed by providing the color camera unit 7 which is obtained through the image processing unit and the image calculation processing unit 8 which performs calculation processing on the image signal of the color camera unit 7.

Further, a glass plate 6 is arranged at the emission end of the color separation prism 5 via an adhesive, and a holder 9 for holding the glass plate 6 and the holder 9 are arranged in the optical axis direction of the color separation prism 5. An optical path is obtained by combining a moving stage 10 to be moved, an ultraviolet light source 11, a light guide 12 for guiding ultraviolet light emitted from the ultraviolet light source 11 to the glass plate 6, and the above-described color separation prism optical path length measuring device. A color separation prism whose length is adjusted with high precision can be manufactured at high speed.

[0018]

As described above, the present invention provides a line-type illumination device, a lens unit, a slit inclined forward and backward with respect to the optical axis of the lens unit , a half mirror, a color camera unit, and an image processing unit. With this arrangement, it is possible to realize an excellent color separation prism optical path length measuring device capable of measuring the color separation prism with high accuracy and high speed.

Further, a glass plate is disposed at the exit end of the prism via an adhesive, and a holder for holding the glass plate, a moving stage, an ultraviolet light source, a light guide, and the above-described color separation prism optical path length measuring device are provided. By combining the above, an excellent color separation prism bonding apparatus capable of manufacturing a color separation prism having an optical path length adjusted with high precision at a high speed can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a color separation prism optical path length measurement and color separation prism bonding apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory view of the measurement principle of the color separation prism optical path length measuring device in the present embodiment.

FIG. 3 is a characteristic diagram of a detection output by the color separation prism optical path length measuring device in the embodiment.

FIG. 4 is a configuration diagram of a conventional color separation prism optical path length measuring apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Line-type illuminating device 2 Slit 3 Half mirror 4 Lens unit 5 Color separation prism 6 Glass plate 7 Color camera 8 Image processing part 9 Glass holder 10 Moving stage 11 UV (ultraviolet) light source 12 Light guide

Continuation of the front page (56) References JP-A-3-239942 (JP, A) JP-A-4-290090 (JP, A) JP-A 64-24583 (JP, A) (58) Fields studied (Int .Cl. ⁷ , DB name) G01M 11/00-11/02 G01B 11/02 G01N 21/41 H04N 9/09

Claims (1)

(57) [Claims] And 1. A line-type illuminating device, and a lens unit for focusing the light passing through the generated slit from the line-type illuminating device emitting end of the color separation prism, the Renzuyu
Said slit tilted back and forth relative to the optical axis of the knit, and a half mirror disposed in front of the lens unit, before
A color camera unit that captures the reflected light from the emission end of the color separation prism via the half mirror; and an image operation processing unit that performs an operation process on an image signal of the color camera unit; and an imaging surface of the color camera. The har
The distance of the mirror is the distance between the half mirror and the slit.
The color camera and the half
And a color separation prism optical path length measurement device in which the color and the slit are arranged .