JPH0335285Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention deforms the cornea of the eye to be examined by blowing a stream of compressed air onto the eye to be examined, and detects the physical quantity indicating the deformation and the pressure of the fluid. The present invention relates to an airflow spraying device for a non-contact tonometer that determines intraocular pressure from the correlation between this physical quantity and the pressure of fluid.

(Prior Art) As an airflow blowing device for this type of non-contact tonometer, there is a conventional one shown in FIG. 3, for example.

In this airflow blowing device, an arm 2 of a rotary solenoid 1 is connected to a piston rod 4 integral with a piston 3, and a compression chamber 6 of a cylinder 5 in which the piston 3 is disposed is communicated with a nozzle 7. The axis of this nozzle 7 is directed toward the eye examination position. Moreover, when the rotary solenoid 1 is energized, the arm 2 is rotated clockwise,
When the power supply is stopped, the arm 2 is returned to its current state by the force of a spring (not shown). Furthermore, an air bleed hole 8 is formed in the lower part of the cylinder 5 to bleed air from the compression chamber 6 at the beginning of compression.

In such a configuration, when the rotary solenoid 1 is activated and the arm 2 is rotated clockwise, the piston 3 is displaced upward via the piston rod 4, and the pressure within the compression chamber 6 increases. The air in the compression chamber 6 is blown from the nozzle 7 onto the eye 9 at the eye examination position.

On the other hand, in such an airflow blowing device, when the power supply to the rotary solenoid 1 is stopped after blowing the airflow to the eye 9 to be examined, the rotary solenoid 1
is returned to its current state by the force of a spring (not shown), and the piston 3 is displaced downward. As a result, the pressure within the compression chamber 6 decreases, and air around the eye 9 to be examined is sucked into the compression chamber 6 from the nozzle 7 .

(Problem to be Solved by the Invention) However, when the airflow is blown onto the eye 9 to be examined as described above, the tears in the eye 9 to be examined will scatter.
The scattered tears were sucked into the compression chamber 6 from the nozzle 7 after the air was blown, and were blown onto the eye of the next patient, which was unfavorable from a sanitary standpoint.

(Purpose of the invention) Therefore, the purpose of this invention is to provide an airflow spraying device for a non-contact tonometer in which the tears scattered from the subject's eye during air intake are not sucked into the compression chamber from the nozzle. It is.

(Means for solving the problem) In order to achieve this object, this invention arranges a piston in a cylinder, divides the inside of the cylinder into an atmospheric suction chamber and a compression chamber, and compresses the piston. In the airflow spraying device for a non-contact tonometer, the airflow spraying device for a non-contact tonometer is configured to blow the compressed air toward an eye examination position from a nozzle communicating with the compression chamber by compressing the air in the compression chamber by advancing the air into the chamber side. 1. A one-way valve is attached to the piston so that air can flow only from the atmospheric suction chamber side to the compression chamber side, and an air suction port for sucking atmospheric air is provided in the atmospheric suction chamber, so that air can flow from the atmospheric side to the compression chamber side. The airflow blowing device for a non-contact tonometer is characterized in that a second one-way valve that allows air to flow only toward the suction chamber is provided at the air suction port.

(Function) According to this configuration, when the piston is displaced toward the compression chamber, the first one-way valve is closed, so the air in the compression chamber is compressed and the air in the compression chamber is discharged from the nozzle. Blown out at the optometry position. At this time, the atmosphere suction chamber becomes a negative pressure, and this negative pressure causes the second one-way valve to open, and the atmosphere is sucked into the atmosphere suction chamber.

On the other hand, when the piston is returned to its current state after air blowing is finished, the air in the atmospheric suction chamber is compressed and the second one-way valve closes, and the first one-way valve is opened by the air pressure in the atmospheric suction chamber. Air is then sucked into the compression chamber from the atmospheric suction chamber side of the cylinder.
At this time, since almost no negative intake pressure acts on the nozzle, air around the subject's eye is not sucked into the compression chamber from the nozzle.

(Example) Hereinafter, an example of this invention will be described based on FIGS. 1 and 2.

In FIGS. 1 and 2, 10 is a cylinder of the airflow blowing device, 11 is a cylindrical piston disposed within the cylinder 10, 11a is an end wall closing one end of the piston 11, and 11b is an end. This is a valve hole provided around the wall 11a. The piston 11 divides the inside of the cylinder 10 into a compression chamber 12 and an atmospheric suction chamber 13.

A valve hole 11 is provided in the end wall 11a of the piston 11.
A reed valve 14 for opening and closing b is installed as a first one-way valve. This reed valve 14 is provided so that air can flow only from the atmospheric suction chamber 13 side to the compression chamber 12 side.

A linear DC motor 15 serving as a linear actuator is mounted coaxially with the cylinder 10 at the end of the cylinder 10 on the atmospheric suction chamber 13 side.
This linear DC motor 15 includes a bobbin 16 whose one end is fitted into the cylinder 10, a coil 17 wound around the bobbin 16, and a rod 18 made of a permanent magnet inserted into the bobbin 17. . One end of the bobbin 16 is fixed to the cylinder 10 with a screw 16a. An air suction port 19 communicating between the atmospheric suction chamber 13 and the atmosphere is formed at one end of the bobbin 16, and a filter 20 is attached to the air suction port 19. Also, one end of the rod 18 is attached to the center of the end wall 12a of the piston 11 with a screw 2.
It is fixed at 1. In such a linear DC motor 15, when the coil 17 is energized and the polarity of the bobbin 16 is reversed to the polarity of the rod 18, the rod 18 is moved toward the compression chamber 12 by magnetic force.
Also, if the direction of current to the coil 17 is reversed and the polarity of the bobbin 16 is made the same as the polarity of the rod 18,
The rod 18 is magnetically attracted to the bobbin 16 side.

Further, a reed valve 22 is provided at the end of the bobbin 16 on the side of the air suction chamber 13 to open and close the air suction port 19.
is installed as a second one-way valve. This reed valve 22 is provided so that air can flow only from the atmospheric side to the atmospheric suction chamber 13 side.
Further, a compression chamber 1 is provided on the compression chamber 12 side of the cylinder 10.
A hollow nozzle attachment member 24 is attached to this tube portion 23, and a nozzle 25 communicating with the tube portion 23 is attached to this nozzle attachment member 24. In addition, in the figure, 2
6 is the eye to be examined at the optometry position.

Next, the operation of the airflow blowing device of the non-contact tonometer having such a configuration will be explained.

In such a configuration, linear DC motor 1
When the coil 17 of No. 5 is energized and the polarity of the bobbin 16 is reversed to that of the rod 18, the rod 18 is moved toward the compression chamber 14 by magnetic force. Along with this, the piston 11 is displaced toward the compression chamber 14, and
The reed valve 14 closes as shown in FIG.
Compression of the air inside begins. And compression chamber 1
4 is blown out from the nozzle 25 toward the eye 26 at the eye examination position. At this time, the reed valve 22, which is a second one-way valve, opens and the atmosphere is sucked into the atmosphere suction chamber 13 through the air filter 20 and the air suction port 19.

Furthermore, if the direction of current to the coil 17 of the linear DC motor 15 is reversed and the polarity of the bobbin 16 is made the same as the polarity of the rod 18, the rod 18 will be attracted to the bobbin 16 side by magnetic force. Accordingly, the piston 11 is displaced toward the atmospheric suction chamber 13, the air in the atmospheric suction chamber 13 is compressed, and the reed valve 22 is closed as shown in FIG. As a result, the reed valve 14, which is the first one-way valve, opens into the atmospheric suction chamber 13.
The valve is opened by the internal pressure, and air in the atmospheric suction chamber 13 flows into the compression chamber 12 through the valve hole 11b. As a result, no air is sucked through the nozzle 25.

In the embodiment described above, the piston 11 is driven by a linear actuator.
Although the DC motor 15 is used for this purpose, the present invention is not limited to this, and a rotary solenoid may also be used.

(Effects of the invention) As explained above, this invention includes disposing a piston in a cylinder, dividing the inside of the cylinder into an atmospheric suction chamber and a compression chamber, and allowing the piston to advance toward the compression chamber. In the airflow blowing device for a non-contact tonometer, the compressed air is sprayed from a nozzle communicating with the compression chamber toward an eye examination position by compressing the air in the compression chamber. The piston is mounted so that air can flow only from the atmospheric suction chamber side to the compression chamber side, and an air suction port for sucking atmospheric air into the atmospheric suction chamber is provided to allow air to flow only from the atmospheric side to the atmospheric suction chamber side. Since the second one-way valve that allows air to flow is provided at the air suction port, it is possible to reliably prevent tears scattered from the subject's eye during air suction from being sucked into the compression chamber from the nozzle.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an airflow blowing device for a non-contact tonometer showing an embodiment of this invention. Second
The figure is a cross-sectional view showing the operating state of the airflow blowing device shown in FIG. 1 and others. FIG. 3 is a schematic explanatory diagram of a conventional airflow blowing device for a non-contact tonometer. 10...Cylinder, 11...Piston, 11a
... End wall, 11b ... Valve hole, 12 ... Compression chamber, 1
3...Atmospheric suction chamber, 14...Reed valve (first one-way valve), 15...Linear DC motor (linear actuator), 19...Air suction port, 22...
Reed valve (second one-way valve), 25... Nozzle, 2
6... Eye to be examined.

Claims (1)

[Claims for Utility Model Registration] A piston is disposed inside the cylinder to divide the inside of the cylinder into an atmospheric suction chamber and a compression chamber, and the piston is advanced toward the compression chamber to compress the air in the compression chamber. In the airflow spraying device for a non-contact tonometer, the compressed air is sprayed from a nozzle communicating with the compression chamber toward an eye examination position, by connecting a first one-way valve to the piston on the side of the atmospheric suction chamber. At the same time, an air suction port for sucking atmospheric air is provided in the atmospheric suction chamber so that air can flow only from the atmospheric side to the atmospheric suction chamber side. 2. An airflow blowing device for a non-contact tonometer, characterized in that a one-way valve is provided at the air suction port.