JP3441146B2 - Exposure table light source position measurement device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure table light source position measuring apparatus for selectively coating a plurality of phosphors on the inner surface of a panel of a cathode ray tube. 2. Description of the Related Art As shown in FIG. 3, a color cathode ray tube has, for example, a stripe-shaped red light-emitting phosphor 5R, a green light-emitting phosphor 5G, and a blue light-emitting phosphor 5B on the inner surface of a front panel glass 5. Phosphor screens are arranged in a regular order. further,
A shadow mask 4 having a large number of regularly arranged electron beam apertures 4a is disposed in close proximity to the phosphor screen. One electron beam aperture 4a corresponds to a pair of a red light emitting phosphor 5R, a green light emitting phosphor 5G, and a blue light emitting phosphor 5B on the phosphor screen. [0003] The three electron beams Gr, Gg, Gb disposed opposite to the phosphor screen are deflected in the horizontal and vertical directions by a deflector disposed outside the tube.
According to the parallax principle, each phosphor is projected and emitted through the electron beam aperture 4a of the shadow mask 4, thereby displaying a color image. According to the basic operation of such a color cathode ray tube, for example, the electron beam Gr for red causes the red light-emitting phosphor 5R to properly strike and emit light, and the green light-emitting phosphor 5G and the blue light-emitting phosphor 5B to emit light. It is absolutely necessary to avoid shooting. Accordingly, the step of selectively applying the three-color light-emitting phosphors to the inner surface of the panel is performed by exposing and developing the panel and the shadow mask to be combined. That is, a light source is arranged in a virtual electron beam source that assumes each electron beam emitted from the electron gun, and light from this light source passes through the electron beam aperture 4a of the shadow mask and reaches each part of the inner surface of the panel. The photoresist film applied to the phosphor screen is exposed so as to be corrected by an exposure lens so as to match the locus of the light as much as possible. Further, the exposure-development processing of such a panel requires at least three times for red, green and blue, and a total of four exposure-development processings are required when a light absorber is provided between each phosphor. Is required. Further, in a mass production process of a color cathode ray tube, productivity is extremely reduced unless a number of exposure devices are placed and exposure and development processes are performed simultaneously. To do this,
It is necessary to prepare a reference exposure table so that all the panels of a specific size can be subjected to exposure processing under the same conditions, and to adjust the positions of the light sources in all the exposure apparatuses using the reference exposure table. FIG. 4 shows a schematic configuration of an apparatus for adjusting and measuring the light source position of the reference exposure table. That is, a panel mounting portion for a cathode ray tube is provided above the reference exposure table 1, and a panel glass 5 on which a shadow mask 4 is mounted is placed on the panel mounting portion. An exposure light source 2 is provided inside the exposure table 1.
The exposure lens 3 is disposed between the exposure light source 2 and the panel glass 5. In such a state, the light from the exposure light source 2 passes through the electron beam aperture 4a of the shadow mask 4 and reaches each part of the inner surface of the panel glass 5 while the optical path is corrected by the exposure lens 3. On the other hand, on the outer surface of the panel glass 5, an image and position of light reaching the inner surface of the panel glass 5 are measured by a portable low-magnification microscope 6, and the exposure light source 2 and the exposure lens 3 are measured.
Adjust the position of. Next, this panel is moved to another exposure table to be adjusted, and the image and the position of the inner surface of the panel are measured in the same manner, and the exposure table is adjusted so that this position coincides with the reference exposure table. Do. Basically, such an adjusting operation is performed by an electronically semi-automatic apparatus as shown in, for example, Japanese Patent Publication No. 63-66020. That is, as shown in FIG. 5, an image receiving unit 8 having an optical sensor such as a semiconductor line sensor or a CCD camera is mounted on the panel mounting surface of the exposure table 1 so as to face the exposure light source 2. A pinhole plate 7 having a small hole is arranged at a position corresponding to the electron beam opening of the shadow mask between the image receiving section 8 and the exposure lens 3. That is, the light from the exposure light source 2 is
Then, the optical path is corrected, passes through the small hole of the pinhole plate 7, and the image of the light source is connected to the optical sensor of the image receiving unit 8 by the principle of the pinhole camera and converted into an electric signal. The electric signal is digitally processed and displayed, for example, by a light amount peak value and its position by a microcomputer of an image processing unit (not shown). When the displacement of the light source position is measured by such a method, the relationship is as shown in FIG. That is, when the distance between the exposure light source 2 and the small hole of the pinhole plate 7 is L, and the distance between the small hole of the pinhole plate 7 and the optical sensor of the image receiving unit 8 is r, the position of the exposure light source 2 is from 2a. 2b, the received light image on the optical sensor moves from 8a to 8b by R2, the exposure light source 2 is calculated from the proportional expression of L: r = R1: R2.
Can be easily calculated. When the displacement of the position of the exposure light source is measured by the above method, the measurement accuracy is determined by the ratio of L and r, assuming that an optical sensor having the same resolution is used. Will be done. That is, the displacement of the light source is r /
It is obtained as a shift amount in the image receiving portion at L times. Since the distance L between the exposure light source 2 and the small hole of the pinhole plate 7 is a substantially constant value determined by the size of the panel, the distance L between the small hole of the pinhole plate 7 and the optical sensor The longer the distance r is, the higher the measurement accuracy is. However, as the color cathode ray tube becomes larger in size, the resolution is improved, that is, the pitch of the phosphor dots is reduced, and the accuracy of measuring the displacement of the exposure light source is higher. Is needed.
Also, the exposure table is designed to increase productivity and space efficiency.
It is designed to be able to process small to large panels with one exposure table. Therefore, the small hole of the pinhole plate 7 and the image receiving portion 8
In order to increase the distance r from the optical sensor, the size of the measuring device must be increased. However, the size of the measuring device is limited due to problems such as handling and space efficiency. The present invention has been made in view of the above-mentioned problems, and it is possible to measure the displacement of the exposure light source without increasing the size of the measuring apparatus even in a large or high-definition color cathode ray tube. It is an object of the present invention to provide an exposure table light source position measuring device capable of substantially increasing the distance between a small hole of a hole plate and an optical sensor of an image receiving unit. According to the present invention, there is provided an exposure table in which a panel mounting portion of a cathode ray tube is provided at an upper portion and at least a light source and an exposure lens are provided inside, and an exposure table is provided above the panel mounting portion. A pinhole plate having a small hole, an image receiving unit that receives a light source image from the light source through the small hole and converts the light source image into an electric signal, and an image processing unit that processes the electric signal from the image receiving unit. In an exposure table light source position measuring device, at least one mirror is arranged in an optical path between the pinhole plate and the image receiving unit, and an exposure table light source position measuring device that detects reflected light from the mirror at the image receiving unit. By doing so, the above object is achieved. In order to measure the light source position deviation at the image receiving portion with a single exposure table from a small cathode ray tube exposure table to a large cathode ray tube exposure table, the exposure light source 2 and the pinhole plate are used. The distance L from the small hole 7 increases as the size increases. Along with this, the distance r between the small hole of the pinhole plate and the optical sensor of the image receiving section also increases. Therefore, if the distance r between the small hole of the pinhole plate and the optical sensor of the image receiving unit is linearly increased, it is inevitable that the measuring device becomes large. Here, since the optical sensor of the image receiving section only needs to accurately receive the light from the exposure light source, the arrangement position of the optical sensor of the image receiving section is not limited to connecting the exposure lens to the small hole of the pinhole plate. It does not need to be on a straight line extension.
Therefore, regardless of the linear distance between the small hole of the pinhole plate and the optical sensor of the image receiving unit, it is sufficient that the optical path connecting the small hole of the pinhole plate and the optical sensor of the image receiving unit is substantially long. That is, if at least one mirror is arranged on the optical path connecting the small hole of the pinhole plate and the optical sensor of the image receiving section, and light from the exposure light source is reflected by this mirror, The optical path length between the small hole and the optical sensor of the image receiving section can be substantially lengthened, and the optical sensor of the image receiving section can be freely arranged at an arbitrary position depending on the setting of the reflection angle of the mirror. Embodiments of the present invention will be described below in detail. FIG. 1 shows a schematic configuration of an exposure table light source position measuring apparatus according to an embodiment of the present invention. In FIG. 1, the same components as those in FIG. 5 are denoted by the same reference numerals. In FIG. 1, a mirror 9 is arranged on the optical path between the small hole of the pinhole plate 7 and the optical sensor of the image receiving section 8. Therefore, light passing through the small hole of the pinhole plate 7 from the exposure light source 2 via the exposure lens 3 is reflected by the mirror 9. An image receiving unit 8 having an optical sensor is arranged on an extension of the light reflected by the mirror 9. FIG. 2 shows the optical path of FIG. 1. The distance L between the exposure light source 2 and the small hole of the pinhole plate 7 corresponds to the distance between the small hole of the pinhole plate 7 and the optical sensor of the image receiving unit 8. The distance r is the distance r1 between the small hole of the pinhole plate 7 and the mirror 9 and the distance of the mirror 9
And the distance r2 between the image receiving unit 8 and the optical sensor. That is, the arrangement position of the optical sensor of the image receiving section 8 can be moved from a virtual position indicated by a dotted line to a position indicated by a solid line. Therefore, the small hole of the pinhole plate 7 and the image receiving portion 8
By setting the reflection angle of the mirror 9 appropriately even if the distance r from the optical sensor to the optical sensor is set to be sufficiently long as required for the measurement accuracy, the arrangement position of the optical sensor of the image receiving unit 8 can be arbitrarily moved. As described above, the distance r between the small hole of the pinhole plate 7 and the optical sensor of the image receiving section 8 is sufficiently long as required for measuring accuracy, and a certain measuring precision is maintained. Since the arrangement position of the optical sensor can be set in accordance with the space of the exposure table, the size of the measuring device can be reduced. In the above embodiment, an example has been described in which one mirror is arranged on the optical path between the small hole of the pinhole plate 7 and the optical sensor of the image receiving section 8, but the present invention is not limited to this. Alternatively, two or more mirrors may be arranged in accordance with the space distribution of the exposure table. As described above, according to the present invention, by disposing at least one mirror on the optical path between the small hole of the pinhole plate and the optical sensor of the image receiving section, the pinhole Since the distance between the small hole of the plate and the optical sensor of the image receiving unit is long enough to require the measurement accuracy, the position of the optical sensor of the image receiving unit can be set according to the space of the exposure table. In addition, the size of the measuring device can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram showing an exposure table light source position measuring device according to an embodiment of the present invention. FIG. 2 is a schematic diagram for explaining an optical path of light in FIG. FIG. 3 is a schematic diagram for explaining the operation of the color cathode ray tube. FIG. 4 is a schematic configuration diagram showing a conventional exposure table light source position measuring device. FIG. 5 is a schematic configuration diagram showing a conventional exposure table light source position measuring device. FIG. 6 is a schematic diagram for explaining an optical path of the light in FIG. 5; [Description of Signs] 1 ... Exposure table 2 ... Exposure light source 3 ... Exposure lens 4 ... Shadow mask 5 ... Panel glass 7 ... Pin hole plate 8 ... Image receiving unit 9 ... Mirror

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-214246 (JP, A) JP-A-55-159539 (JP, A) JP-A-58-223701 (JP, A) 251700 (JP, A) JP-A-52-63661 (JP, A) JP-A-62-271326 (JP, A) JP-A-62-154526 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) H01J 9/227 H01J 9/42 G01B 11/00

Claims (1)

(57) [Claim 1] An exposure table in which a panel mounting part of a cathode ray tube is provided at an upper part and at least a light source and an exposure lens are provided therein, and a small light source disposed above the panel mounting part. An exposure table including at least a pinhole plate having a hole, an image receiving unit that receives a light source image from the light source through the small hole and converts the light source image into an electric signal, and an image processing unit that processes the electric signal from the image receiving unit In the light source position measuring device, at least one mirror is arranged in an optical path between the pinhole plate and the image receiving unit, and reflected light from the mirror is detected by the image receiving unit. measuring device.