JPH0989656A - Condensed-beam power measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power measuring device in which an individual difference by every measuring operation or by a measuring operator is eliminated, which is not influenced by a position of incidence and an angle of incidence on a photosensor at a photodetection part and by a disturbance cause such as external light or the like other than a condensed beam and by which head radiation power can be measured precisely and stably. SOLUTION: A condensed-beam power measuring device is constituted of a photodetection part 5 which is composed of a photosensor 3 used to receive a condensed beam 2 radiated from an objective lens 1 and of a photosensor- fixation member 4 formed of a light-shielding member used to shield external light to the photosensor 3 to be fixed in a desired position perpendicularly to the axis of the objective lens 1 and of a power computing part 6 which computes power on the basis of a detection signal (a) which is output by the photodetection part 5. In a measuring operation, the photodetection part 5 is attached to an actuator enclosure 7 by a screw 8, and the photosensor 3 receives only the condensed beam 2 in an always desired condensed-beam measuring part 9 in a state that the photosensor 3 is shielded from the external light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focused beam power measuring device, and more particularly to a focused beam power measuring device for accurately measuring the outgoing power emitted from an optical head of an optical disk master exposure apparatus.

[0002]

2. Description of the Related Art Conventionally, in this type of focused beam power measuring device, the power of a focused beam emitted from an optical head of an optical disk master exposure apparatus is measured by a measurer by hand with an optical sensor light receiving portion of the head objective lens. The power of the focused beam was measured by moving to just below and receiving the light.

FIG. 2 is a block diagram showing an example of a conventional focused beam power measuring device.

As shown in FIG. 2, the conventional focused beam power measuring device has a focused beam 1 focused by an objective lens 11.
It is composed of an optical sensor 13 that receives 2 and a power calculation unit 16 that receives the detection signal b output from the optical sensor 13 and calculates the focused beam power. When measuring the focused beam power, the measurer uses the optical sensor 13
To the objective lens 11 as close as possible to measure the focused beam power.

[0005]

In this conventional focused beam power measuring instrument, the operator manually adjusts the position of the optical sensor of the focused beam power measuring instrument. The incident position and incident angle of the focused beam on the optical sensor may change, causing “variability” in the light receiving sensitivity of the optical sensor. Furthermore, it is accurate and stable due to disturbance factors such as external light other than the focused beam. However, there is a drawback that the focused beam power cannot be measured.

[0006]

The present invention is a focused beam power measuring device for measuring the power of a focused beam emitted from an objective lens of a device to be measured, wherein the focused beam emitted from the objective lens is focused. A light detection unit including a light sensor that receives a beam, a light blocking member that blocks outside light to the light sensor, and a light sensor fixing member that fixes the light sensor at a desired position perpendicular to the axis of the objective lens. A mounting means for mounting the photodetection unit on the device under test is provided.

[0007]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the focused beam power measuring device of the present invention. As shown in FIG. 1, the focused beam power measuring device of the present invention comprises a light detection unit 5 and a power calculation unit 6, and the light detection unit 5 detects the focused beam 2 emitted from the objective lens 1. It is composed of a light sensor 3 for receiving light, and a light sensor fixing member 4 made of a light shielding member for blocking outside light to the light detecting sensor 3 fixed at a desired position perpendicular to the axis of the objective lens 1, and The power calculator 6 calculates the power from the detection signal a output from the photodetector 5.

Here, in order to measure the focused beam power using the focused beam power measuring device of the present invention, the photodetection section 5 is attached to the actuator casing 7 of the optical disk master exposure device with the screw 8. Then, the optical sensor 3 always receives only the focused beam 2 at the desired focused beam measurement point 9 while being shielded from the external light.

The photodetector 5 outputs the detection signal a of the condensed beam 2 received by the photosensor 3. The power calculator 6 calculates the focused beam power based on the input detection signal a.

[0011]

As described above, the focused beam power measuring device of the present invention interrupts the external light and always receives only the focused beam at the desired measurement point by the optical sensor, so that Accurate and stable collection without being affected by “variation” in the light receiving sensitivity due to changes in the incident position and incident angle of the focused beam on the optical sensor due to individual differences of the measurer and the disturbance factors due to external light on the optical sensor. There is an effect that the light beam power can be measured.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a focused beam power measuring device of the present invention.

FIG. 2 is a configuration diagram showing an example of a conventional focused beam power measuring device.

[Explanation of symbols]

 1,11 Objective lens 2,12 Focused beam 3,13 Photosensor 4 Photosensor fixing member 5 Photodetector 6,16 Power calculator 7 Actuator housing 8 Screw 9 Focused beam measurement point a, b Detection signal

Claims (1)

[Claims] 1. A focused beam power measuring device for measuring the power of a focused beam emitted from an objective lens of a device under test, the optical sensor receiving the focused beam emitted from the objective lens, A light detecting section comprising a light blocking member for blocking outside light to the light sensor and a light sensor fixing member for fixing the light sensor at a desired position perpendicular to the axis of the objective lens, and the light detecting section to be measured. A focused beam power measuring instrument, comprising: mounting means for mounting on a device.