JPH052930B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a turret drive device, particularly to the photoelectric conversion characteristics (especially smear, blooming, etc.) of an image sensor, etc.
This invention relates to a turret driving device capable of accurately positioning a turret having a plurality of filters in order to appropriately and accurately set an optical environment for performing measurements of dark current, spectral sensitivity, sensitivity unevenness, element defects, etc. .

In recent years, solid-state imaging devices that can perform functions such as photoelectric conversion, charge storage, transfer, detection, and processing simply by utilizing the physical properties of solid-states have been attracting attention. This is because solid-state image sensors are smaller than image pickup tubes,
This is because it has advantages such as light weight and low power consumption. Furthermore, manufacturers can manufacture the product at low cost through mass production, and users can easily utilize it in various fields. However, in terms of performance, the optical environment characteristics and temperature environment characteristics of photoelectric conversion characteristics such as smear, blooming, dark current, spectral sensitivity, sensitivity unevenness, and element defects are currently less stable than that of image pickup tubes.

Therefore, from the viewpoint of performance measurement and quality inspection of an image sensor, it is desirable to measure its photoelectric conversion characteristics in various optical environments and temperature environments. By using an optical filter, light of various wavelengths and light amounts are appropriately selected, and the reference light is illuminated on the element through the selected optical filter. Accurate positioning of the selected optical filter is important here, otherwise the desired optical environment cannot be obtained and accurate measurements cannot be made.

A conventional turret drive device for driving and positioning filters for this accurate measurement uses a turret 31 having a plurality of different filters 30 coaxially with a ratchet wheel 33, as shown in FIG. The turret 31 is fixedly installed, and the operator manually rotates the turret 31 while visually checking the scale 32 provided on the side surface of the turret 31.
Select the desired filter 30 and connect the light source 10 and element 1.
1. In this case, the selected filter 30 is positioned and fixed by dropping the pawl of the spring 34 into the notch of the ratchet wheel 33.

In addition, as another turret drive device, the second
As shown in the figure, the turret 31 is connected to the connecting gear 37.
There is one that is driven by a stepping motor 38 via. In this case, the positioning of each filter 30 provided on the turret 31 is
This is done by providing a protrusion 35 or the like on the stepping motor 1 and setting the reference position of the stepping motor 38 using a switch 36.

However, when measuring the performance of an image sensor, etc., it is necessary to control not only the optical environment but also the temperature environment, which increases the frequency of selecting and positioning a desired filter. It is efficient and uneconomical. Furthermore, in the device shown in Fig. 2, the positioning accuracy of the filter depends on the accuracy of the stepping motor, and if a positional deviation occurs,
There is a drawback that readjustment is troublesome and the position of the filter cannot be fixed unless voltage is constantly applied to the stepping motor. In addition, there is a limit to the number of filters that can be attached to one turret, so it is necessary to replace the turret, but each time the turret is replaced, it is difficult and complicated to adjust the filter and the stopping position of the stepping motor. It has the disadvantage of being.

The present invention has been made in view of the above-mentioned drawbacks of the conventional example, and provides a turret drive device that is capable of efficiently and reliably positioning and fixing a filter, and that also allows easy replacement of the turret. The purpose is to

To achieve the above object, the present invention provides a turret drive device that rotates a turret provided with a plurality of filters in the rotational direction, selects and positions one of the filters, and comprises: a rotating shaft of the turret; a cam member which has different rotation axes and has a shape in which a part of the outer periphery of a disc is cut out, and rotates once every time the turret rotates by a predetermined angle such that the filter of the turret is replaced with an adjacent filter; , a stopper member that abuts an outer peripheral portion of the cam member, and a biasing member that biases the stopper member toward the cam member, and the turret rotates so that the selected one of the filters is in a predetermined position. When the turret is moved to the position, the stopper member comes into contact with the notch and is fixed by the biasing force, thereby fixing the turret.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 3a is a front view of one embodiment of the turret drive device of the present invention, and FIG. 3b is a side view of FIG. 3a. As shown in each figure, in this turret drive device, a plurality of interference filters 14 are fixedly arranged on concentric lines, and turrets 31 and 31 of the interference filters 14 are each formed with a predetermined number of teeth.
An ND filter 14' drives a similarly fixed turret 31'. The two turrets 31, 31' are driven by drive motors 39, 3, respectively.
controlled by 9' and positioned at a predetermined position;
The illumination light source 10 illuminates an image sensor (not shown) through the selected interference filter 14 and ND filter 14', and the photoelectric conversion characteristics of the image sensor are measured.

FIG. 4 is a block diagram of a drive system for one of the turrets 31 having an interference filter 14, for more specifically explaining the structure of FIGS. 3a and 3b. Fourth
In the figure, since the drive system for the other turret 31' (see FIG. 3b) having an ND filter has a similar construction, illustrations are omitted except for the cam 44' and the rotating shaft 51'.

A gear 45 is fitted onto the rotating shaft 50 of the drive motor 39, and the gear 45 is configured to mesh with the teeth of the turret 31 when the turret 31 is mounted on the device. gear 45
is in mesh with a gear 46 fixed coaxially with a cam 44 serving as a cam member at a rotation axis 51 different from the rotation axis (not shown) of the turret 31, and this gear 46 is in mesh with a gear 47. A gear 48 is fixed to the same shaft 52 as the gear 47 , and the gear 48 meshes with a gear 49 fitted onto the shaft 53 of the potentiometer 40 . Note that the reference numeral 40' in FIG. 3 indicates a potentiometer for the other turret 31'.

The above-mentioned cam 44 has a plane part 44a as one notch formed by cutting out a straight line in a disc, and the plane part 44a or the outer circumferential part 44b of this cam 44 is provided with a biasing member. spring 4
A stopper 42 as a substantially rectangular stopper member biased by 1 is in contact with the stopper 42 . A long hole 42a is formed in the center of the stopper 42 and faces in a direction perpendicular to the longitudinal direction, that is, in the direction of the spring 41, and a shaft 54 is attached to this long hole 42a. Thereby, the stopper 42 is not only rotatable around the shaft 54 but also slidable along the elongated hole 42a. When the cam 44 is in the position shown in FIG.
That is, the stopper 42 is attached to the flat surface 44a of the cam 44.
When they are in contact, it means that the selected interference filter 14 of the turret 31 is accurately positioned between the light source 10 and the image pickup device (not shown).

Incidentally, as shown in FIG. 6, a stopper 42 may be provided for each turret drive system. Reference numeral 43 indicates the rotation axis of the stopper 42. cam 44
may be configured to have two notches, each cut out in parallel straight lines, or may be configured to have a square or a regular polygon.

Next, the relationship among the above-mentioned members will be explained with reference to FIG. The cam 44 rotates once for each interference filter 14 of the turret 31, and the gear 49 of the potentiometer 40 rotates once for each rotation of the turret 31. That is, turret 3
1. The number of teeth of gears 45, 46, 47, 48, and 49 are K31, K45, K46, K47, and K4, respectively.
8, K19, the number of interference filters 14 attached to the turret 31 is N, and the pitch angle of the interference filters 14 is θ, then K45/K31=K45/K46×K46/K47×K48/K49 =K45×K48 /K47×K49...(1) N=360/θ=K31/K46...(2) The following relational expression is obtained. From equations (1) and (2), K46/K31=K46/K47×K48/K49=1/N=θ/360 ∴N=360/θ=K47×K49/K46×K48=K31/K46... (3) If each member is configured to satisfy equation (3),
The relationship described above can be achieved. Although one notch is formed in the cam 44, another notch may be provided on the circumference opposite to this notch, and in this case, the cam 44 rotates by 1/2 rotation. The turret 31 rotates one pitch each time. Furthermore, since the angular division of the potentiometer 40 is determined by the number N of interference filters 14, the gear configuration is not limited to five gears.

One rotation of the turret 31 corresponds to a rotation of the gear 4 fixed to the shaft 53 of the potentiometer 40 (see FIG. 4).
Since it corresponds to one rotation of 9, the turret 31
If the rotational position of one of the interference filters 14 is used as a reference, absolute position information of the turret 31 can be obtained by measuring the resistance value of the potentiometer. This resistance value can be used as an address signal for the CPU 56 (see FIG. 4) when systematically measuring the image sensor.
Furthermore, even if the turret 31 is replaced with another turret, it can be determined from the resistance value of the potentiometer 40 which interference filter 14 of the turret 31 in the previous process was used, and this can be used as position information for the next turret. can.

Next, with reference to FIGS. 4 and 5, the operation of the above embodiment will be explained using the drive system for the turret 31 of the interference filter 14.

When a current is applied to the drive motor 39 for the turret 31 of the interference filter 14 to rotate the rotary shaft 50, the gear 45 rotates in the same direction and by the same angle as the rotary shaft 50. The gear 45 transmits rotation to the turret 31 and gears 46 and 47 of the interference filter 14 at predetermined transmission ratios. Gear 47 and gear 48
are fixed to the same shaft 52, so the gear 4
The rotation transmitted to gear 48 is transmitted to gear 48 via shaft 52.
and further to the gear 49. Since the gear 49 is fixed to the shaft 53 of the potentiometer 40 for the interference filter 14, the shaft 53 of the potentiometer 40 rotates by the same angle in the same direction as the gear 49. Furthermore, since the cam 44 and gear 46 for the interference filter 14 are fixed to the same rotating shaft 51, the rotation transmitted to the gear 46 is
It is transmitted to the cam 44 via the rotating shaft 51 in the same direction and at the same rotation angle. When the cam 44 rotates, the stopper 42 moves along the outer periphery 44b of the cam 44 centering on the shaft 54 by pulling the spring 41 as shown in FIG. Repeat the action of returning to the position. Even if some error occurs in the control of the drive motor 39, the cam 44 is set to the normal position (FIG. 4) by the flat part 44a of the cam 44 and the spring 41, making it possible to accurately position the interference filter 14. .

Furthermore, as shown in FIGS. 8a and 8b, if a sensor 55 such as a micro switch is installed at a location where the amount of movement of the stopper 42 is maximum, even if the spring 4
1. Even if the cam 44 is not in its normal stopping position (Fig. 8a) due to a defect in the cam 44 or other members, the defective stopping position (Fig. 8b) can be detected. This detection signal can be used as a start command signal for a measuring device such as an image sensor in which this device is used, or to drive the drive motor 39 again to correct the position of the cam 44 to the normal position.

In the above embodiments, a spring is used as the biasing member that biases the stopper member toward the cam member, but a link mechanism or the like may also be used.

Since the present invention is configured as described above, it produces the effects described below.

It becomes possible to accurately position and fix a plurality of desired filters efficiently. Also,
When measuring image sensors, especially solid-state image sensors such as CCDs, it is often performed in parallel with temperature and environment control, which takes a lot of time, so automatic control measurements that incorporate a measurement program are effective. Furthermore, unlike the rotation axis of the turret and the rotation axis of the cam member, the cam member rotates once when the turret rotates by a predetermined angle, that is, the angle of one filter. As a result, even if the number of filters increases, there is no need to change the shape of the cam member, and the filters can be positioned with the same high precision.

[Brief explanation of drawings]

1 and 2 are block diagrams of a conventional and other conventional turret drive devices, respectively, FIG. 3a is a front view of an embodiment of the present invention, and FIG. 3b is a diagram of FIG. 3a.
4 is a schematic perspective view of the turret drive system shown in FIGS. 3a and 3b, FIG. 5 is a relationship diagram of the gear configuration shown in FIG. 4, and FIG. 6 is a diagram showing another embodiment of the present invention. FIG. 7 is a perspective view showing the operation of the cam and stopper in FIG. 4; FIG. 8 is a partial front view of the cam and stopper according to another embodiment of the present invention; b shows a state in which the cam is in a normal stop position, and b shows a state in which the cam is in a defective stop position. 10...Light source, 14...Interference filter (optical filter), 14'...ND filter (optical filter), 3
1, 31'... Turret, 39, 39'... Drive motor, 40, 40'... Potentiometer, 41... Spring (biasing member), 42... Stopper (stopper member), 44, 44'... Cam (cam member) ), 45,4
6, 47, 48, 49... Gear, 51, 51'... Rotating shaft, 55... Sensor.

Claims (1)

[Scope of Claims] 1. In a turret drive device that rotates a turret provided with a plurality of filters in the rotation direction and selects and positions one of the filters, a rotation axis different from the rotation axis of the turret. a cam member having a shape in which a part of the outer periphery of a disc is cut out, and rotates once each time the turret rotates by a predetermined angle so that a filter of the turret is replaced with an adjacent filter; and a biasing member that biases the stopper member toward the cam member, and when the turret rotates, the selected one of the filters moves to a predetermined position. The turret driving device according to claim 1, wherein when the notch is pressed, the stopper member comes into contact with the notch and is fixed by the biasing force, thereby fixing the turret. 2. A patent characterized in that a potentiometer whose shaft rotates as the turret rotates is provided, and the selected filter of the turret is determined by reading the resistance value of the potentiometer. A turret drive device according to claim 1. 3. The turret drive device according to claim 2, wherein said potentiometer rotates once when said turret rotates once.