JP3708806B2 - Contact lens manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a contact lens.
[0002]
[Prior art]
Conventionally, as shown in FIG. 2, in the contact lens manufacturing apparatus, a spindle 3 for rotating a contact lens 4 as a workpiece is fixed on a base board 8, and a turning table 7 for turning a tool 5 to make a spherical surface is used as a spindle 3. Is fixed on the base board 8 at the opposite position. Alternatively, as shown in FIG. 3, instead of the turning table, the orthogonally controlled X table 2 and Y table 1 controlled by NC are fixed on the base board 8, and the tool 5 is arranged thereon. Alternatively, as shown in FIG. 4, the turning table 41 is arranged on the X table 2 and the Y table 1 which are orthogonally controlled by NC control.
[0003]
[Problems to be solved by the invention]
Incidentally, the contact lens has a shape as shown in FIG. 5, and even if the concave surface side is taken as an example, R1 (hereinafter referred to as a base curve) 51 for determining the optical characteristics of the lens, tear circulation R2 (hereinafter referred to as a secondary curve) 52 that promotes the contact, and the outermost peripheral portion R3 (hereinafter referred to as a peripheral curve) 53 that controls the wearing feeling of the contact lens, and a curve that connects the intersection of these curves with an inverse R It is made up of R4 · 54 and curve R5 · 55. However, in the above-described conventional technology, the shape of the contact lens 4 is not completed only by turning the turning table 7 once in FIG. In FIG. 3, in order to obtain shape accuracy and surface roughness satisfying the optical characteristics of the center, an extremely high motion accuracy is required for the NC control XY table. Further, in FIG. 4, since the height from the base board 8 to the contact lens 4 is increased, there is a problem that it is difficult to ensure the movement accuracy of the tool 5. Therefore, the present invention solves such a problem, and an object of the present invention is to provide a contact lens manufacturing method for processing the contact lens with high accuracy and high efficiency.
[0004]
[Means for Solving the Problems]
In order to solve the above-described problems, a contact lens manufacturing method according to the present invention is a contact lens manufacturing method in which a contact lens as a workpiece is rotated by a spindle, and a swivel table on which a tool is mounted turns to perform processing. The contact lens inner peripheral portion processing step and the contact lens outer peripheral portion processing step in which the orthogonal XY table on which the spindle is arranged moves to perform processing, and the swivel table is formed by these continuous steps. Can be machined by turning once, and the turning table stops turning in the outer peripheral portion machining step.
[Action]
According to the configuration of the present invention, the machining process is applied to a turning table that processes a base curve portion that requires spherical accuracy and surface roughness, and an NC controlled orthogonal XY table portion that processes an outer peripheral portion having a complicated shape. Since it can be divided, the contact lens can be efficiently processed by one turn. In addition, since the swivel table and NC controlled XY table are arranged separately, the restriction of inferior machine accuracy due to the height of the structure can be eased, and the structure of the swivel table is free. Since the degree has increased, a turning table with good positioning accuracy and motion accuracy can be adopted, and the shape accuracy and surface roughness of the contact lens can be improved.
[0005]
【Example】
An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, a contact lens 4 as a workpiece is supported by a vacuum chuck 14 by a vacuum introduced from a vacuum source 12 through a rotary seal 13, and the vacuum chuck 14 is attached to the air spindle 3 and rotates at high speed. The air spindle 3 is disposed on the X table 2 and the Y table 1 which are orthogonal to each other, and is moved under numerical control by the NC device 15. On the other hand, the tool 5 for processing the contact lens 4 is installed on a vertical movement table 10 for adjusting the height of the contact lens 4, and the vertical movement table 10 is used for determining the turning radius of the tip of the tool 5. The R table 6 is installed on the R table 6 and turns on the turn table 7. A block on the swivel table 7 side and a block on the Y table 1 side are arranged on the same base board 8. The swivel table 7 is composed of an air spindle. The air spindle employs a large volume air spindle in order to make it highly rigid, and is completely closed loop controlled by a rotary encoder 16 in order to improve positioning accuracy. By configuring the swivel table 7 with an air spindle, a swivel table with good rotational motion accuracy and no vibration can be obtained, and a base curve portion that requires optical characteristics can be finished with a good surface. At this time, the structure of the air spindle is large and expensive due to rigidity problems as described above, but since the block on the turning table 7 side and the block on the Y table 1 side are separated, from the base panel 8 to the contact lens 4 This helps to maintain the accuracy of the machine.
[0006]
【The invention's effect】
As described above, when the contact lens manufacturing apparatus of the present invention processes the outer periphery of the contact lens, the turning table stops turning, the spindle is mounted, and the spindle is orthogonally crossed in the XY direction. By moving the orthogonal XY table to be moved and performing machining, the conventional machining method has been improved in efficiency so that it can be machined in a single turn where the swivel table must be swiveled multiple times. And it has the effect that it can process accurately.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a production apparatus of the present invention.
[Figure 2]
[Fig. 3]
FIG. 4 is a longitudinal sectional view of a conventional manufacturing apparatus.
FIG. 5 is a longitudinal sectional view of an example of the shape of a contact lens.
[Explanation of symbols]
1 Y table 2 X table 3 Spindle 4 Workpiece (contact lens)
5 Tool 6 R table 7 Turning table 8 Base panel 10 Vertical movement table 12 Vacuum source 13 Rotary seal 14 Vacuum chuck 15 NC
16 Rotary encoder

Claims (1)

In a contact lens manufacturing method in which a contact lens as a workpiece is processed by being rotated by a spindle.
An inner peripheral portion machining step of the contact lens in which a swivel table equipped with a tool swivels to process,
An outer peripheral portion processing step of the contact lens in which the orthogonal XY table on which the spindle is arranged moves and performs processing,
The contact lens manufacturing method is characterized in that the swivel table can be machined by only one turn by these successive steps, and the turn table stops turning in the outer peripheral portion machining step. .

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