JPH0454932B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a variable power mechanism for an optical device, and in particular, by inserting and removing an additional lens into an optical path in conjunction with the movement of a main lens that reciprocates along an optical axis, a variable power mechanism can be used in multiple stages. This paper relates to improvements in magnification changing mechanisms, mainly for copying machines.

2. Description of the Related Art Hitherto, variable-magnification copying machines that can enlarge and/or reduce an original to make copies have been commercialized, and the number of variable-magnification stages is increasing. The variable magnification mechanism of conventional copying machines is
The main types are those that change the magnification by changing the optical path length by moving the imaging lens and mirror in the optical axis direction, and those that change the magnification by moving the imaging lens and inserting and removing an additional lens into the optical path. It was something. In any of these types, a detection means such as a micro switch or a photo sensor is used to detect and control the movement position of the optical element such as the imaging lens, and the detection means is used to detect and control the movement position of the optical element such as the imaging lens. It is necessary to provide a detection means. Therefore, when the magnification variable mode is multi-staged, the detection means becomes more expensive and complicated in proportion to the number of stages. Also, “From B4
For requests to copy at any magnification instead of a fixed magnification, such as "to A4" or "from B4 to B5,"
It is necessary to add new detection means and control means or to rearrange them, which has the disadvantage of being difficult to implement.

In order to eliminate these drawbacks, the applicant of the present application previously proposed in Japanese Patent Application No. 57-55870 that the main lens was moved in the optical axis direction using a rack and pinion method, and in conjunction with this, the additional lens was moved within the optical path. We proposed a variable magnification mechanism for a variable magnification copying machine that can be inserted and removed, in which the rotation angle of the pinion gear for driving the main lens is read by an encoder, and the drive motor is controlled by the output signal from this encoder.

However, if the magnification changing stroke of this magnification changing mechanism is made longer, the main lens drive system uses a rack-and-pinion system, which leads to an increase in the size of the drive means, and the design of the copying machine with other mechanical elements becomes difficult.・It had the disadvantage of being subject to various restrictions regarding assembly. In addition, it is difficult to adjust the position of each element of the drive means during assembly, and the drive system may be overloaded due to foreign matter entering the rack and pinion, and the inertia of the optical elements may be reduced due to failure of the electrical system such as the motor. There were drawbacks such as runaway due to force, lack of control, and damage to the drive mechanism.

The present invention has been made to eliminate the various drawbacks of the conventional magnification changing mechanism described above, and its first purpose is to improve the stopping position of the driving source of the driving system due to the inertia of heavy members such as the main lens. It is an object of the present invention to provide a novel magnification changing mechanism for an optical device, which has a mechanism that can eliminate misalignment and accurately stop the main lens, etc., at a proper position.

The present invention having the above configuration has the advantage that it can be made smaller and simpler than the conventional magnification changing mechanism of an optical device, and can easily accommodate multi-stage magnification changing modes at low cost. Further, it has the advantage of being able to provide a variable magnification mechanism for an optical device that eliminates runaway of the optical element due to inertial force and allows the positioning means to reliably position the optical element.

Embodiments of the present invention will be described below based on the drawings. As shown in FIG. 1, in the variable power mechanism of the optical device of the first embodiment, a rail 4 supported by a device housing (not shown) is inserted into a base portion 1b of a main lens housing 1 having a main lens 1a. The main lens housing 1 slides on a rail 4 arranged parallel to the optical axis 100 of the main lens 1a. A bearing part 1c is formed in the upper part of the main lens housing 1, and the arm part 6a of the lens frame 6 of the first additional lens 5 and the lens frame 8 of the second additional lens 7 are formed in the bearing part 1c.
The arm portions 8a are each slidably supported. Rotation shaft 6b of arm portion 6a of first additional lens frame 6
A roller arm 6c having rollers 9 is attached thereto. Similarly, a roller arm 8c having a roller 10 is attached to the rotating shaft 8b of the arm portion 8a of the second additional lens frame 8. These rollers 9, 10 roll on upper surfaces 13a, 14a of fixed side walls 13, 14 which have bends 11, 12 at their ends.

Similarly, on the upper surface of the main lens housing 1 opposite to the first and second additional lenses, there is provided a third additional lens 50 having the same configuration as the first additional lens described above.
A lens frame 51 having a lens frame 51 is slidably attached. A click plate 15 having a plurality of click grooves 16 is attached to a device housing (not shown). Click roller 1 that engages with click groove 16
7 is pivotally supported by a click lever 18 which is pivotally supported by a pin 19 implanted in the flange 2, and the click lever 18 is always supported by a click roller 17 by a spring 20.
is biased to engage the click groove.

Further, a lever 21 is formed on the flange 2, and this lever 21 is inserted into a slot opening 24 whose longitudinal direction is in the running direction of the rope 22, which is formed in a guide plate 23 disposed in the middle of the rope 22. It is inserted. This guide plate 23 is connected to a spring 25,
One end of the rope 22, which is provided at the intermediate portion via the idler pulleys 27 and 28, is fixed to a point 41 on the periphery of the position detection pulley 40 via the idler pulleys 27 and 28, and is wound around the pulley 40. On the other hand, the other end of the rope 22 is further wound around a drive pulley 43 with a predetermined diameter through idle pulleys 29 and 30 to obtain a predetermined friction force, and then the position is detected. pulley 40
The pulley 4 is fixed to a point 42 on the periphery of the
It is wrapped around 0.

The driving pulley 43 is attached to the rotational drive shaft of the driving motor 44, and the rope 22 is run by the rotational drive of the driving motor 44, and the guide plate 2
Run 3. The guide plate 23 moves the lever 21, so that the main lens housing 1 slides on the rail 4. On the other hand, the position detection pulley 40 is also rotated by the movement of the rope 22 driven by the drive motor 44. As shown in FIG. 2, this position detection pulley 40 includes an encoder device 61 having a code disk 60.
is installed.

As shown in FIG. 2, the code plate 60 of the encoder device 61 has an annular common (-) contact link 65 on the innermost side of its surface, and four contact links on its outer periphery.
It has a binary code track 66 of digits. The common (-) contact link 65 is connected to the (-) side of a power source (not shown) via a printed lead wire on the back side and a (-) side terminal 67. Further, each track of the binary code track 66 is connected to the counter circuit 70 via the respective back printed lead wires and (+) side terminals 68a, 68b, 68c, and 68d. A brush contact piece 64 is fixed to the rotating shaft 40a of the position detection pulley, and the brush contact piece 64 has the above-mentioned (-)
Contact link 65 and binary code track 6
It is configured to slide and rotate on 6 as the pulley 40 rotates. With this configuration, the amount of rotation angle of the pulley 40 is replaced by the amount of rotation angle of the brush contact piece 64. The brush contact piece 64 changes the conduction state between the surface contact of each track of the binary code track 66 and the common (-) contact link depending on its rotational position, and counts the conduction/non-conduction state with the counter 70. , the amount of rotation angle of the pulley 40 is encoded into a four-digit binary number and output. Taking the state shown in FIG. 2 as an example, when the brush contact piece 64 is at position A, it is [1000], when it is at position B, it is [1100], and when it is at position C, it is [0000]. When it is in position D, it is counted as [0100] and the counter 7
0 is output to the determination circuit 71. This determination circuit 71 receives a selection command signal from a magnification selector switch 72 through an input encoder 73.
The digits are converted into binary numbers and input, and compared with the output from the counter 70. Drive motor 4
4 is controlled by a motor control circuit 74 to which the result of the above comparison is input. In this example,
When the determination circuit 71 determines that the binary signal from the input encoder 73 and the binary signal from the counter 70 are the same, the rotation of the motor 44 is stopped.

As described above, in the present invention, the motor 44 winds up the rope 22, and the main lens housing is moved along the optical axis by a lever member engaged with a guide plate attached to the intermediate portion of the rope 22. An encoder device 6 attached to a position detection pulley 40 rotated by a rope 22 to measure the amount of movement
1, and based on this detected value, the motor 44
is under control. On the other hand, the final positioning of the main lens housing 1 is determined by the engagement between the click groove 16 of the click plate 15 and the click roller 17.

Now, it is assumed that the position A of the brush contact piece 64 of the encoder device 60 in FIG. 2 corresponds to the click groove 16a of the click plate 15 in FIG. 3b. Similarly, it is assumed that position B corresponds to the click groove 16b, position c corresponds to the click groove 16c, and position D corresponds to the click groove 16d. Here, the motor 44
When the brush contact piece 64 of the encoder 60 rotates by rotational angle amounts L ₁ , L ₂ , and L ₃ from the reference position A as a base point, the click roller 17 moves into the click groove 16a due to the movement of the main lens housing 1.
Points A ₁ , A ₂ , at distances l ₁ , l ₂ and l ₃ from
A shall be moved to ₃ . Thereafter, by the tension of the spring 20, the groove slopes 16'b, 16'c or 1
6'd, the click roller 17 is reliably engaged with the click grooves 16a, 16b, and 16c. The relationship between the rotational angle amounts L 1 to 3 and the moving distances l 1 to 3 of the main lens housing 1 is as follows: L ₁ = l ₁ + d L ₂ = l ₂ + d L ₃ = l ₃ + d be. In addition, the above d is the guide plate 23 when the guide plate 23 is stopped, as shown in FIG. 3a.
This is the amount of movement due to the inertial force of the lever 21 that is moved by coming into contact with the rear inner surface 24a of the slot opening 24, based on the rear inner surface 24a of the slot opening 24.

Further, as shown in FIG. 3b, the click groove 16
center and the click roller 17 when the motor is stopped.
When e is the distance between contact point A of .

Next, the operation of the first embodiment will be explained. 1st
4A, the click 17 is engaged with the click groove 16a, only the main lens 1a is on the optical axis 100, and the first additional lens 5 and the second additional lens 7 are on the arm portion 6a, 8a to the outside of the optical axis 100. At this time, the magnification selector switch 72 is set to "equal magnification". next,
For example, when the magnification selector switch 72 is set to the second "reduction" (larger reduction magnification), the motor 4
4 rotates to run the guide plate 23, and the guide plate 2
3 slot opening 24 hooks lever 21 to move main lens housing 1 in the direction of arrow 51 in FIG. When the main lens housing 1 moves until the click roller 17 engages with the click groove 16b, the roller arm 6c of the first additional lens 5 is swung downward by the bent portion 11 of the fixed side wall portion 13. As a result, as shown in Figure 4B, the first
An additional lens 5 is inserted on the optical axis 100. The motor 44 continues to rotate and the brush 64 of the encoder 61 rotates to generate a binary code track 66.
The output signal is encoded by the selector circuit 70 and then input to the determination circuit 71.

On the other hand, for example, if the magnification selector switch 72 is set to the first "reduction" (reduction magnification small), the determination circuit 71 determines that the counter 7
0 and the output from the input side encoder 73 are determined to be different from each other, and the motor control circuit 74 further rotates the motor 44 so that the main lens housing 1
is moved in the direction of arrow 51. Then, when the click roller 17 engages with the click groove 16c,
The roller arm 8c of the second additional lens 7 is swung downward by the bent portion 12 of the fixed side wall portion 14.
As a result, as shown in FIG. 4C, the second additional lens 7 is inserted on the optical axis 100 together with the first additional lens 5. At this time, the brush 64 of the encoder 60 rotates to position c and inputs the signal to the counter circuit 70, and the counter circuit 70 inputs the [0000] code to the determination circuit 71.

At this time, since the second "reduction" set command of the magnification selector switch 72 is input as the code [0000] to the determination circuit 71 via the encoder 73, the determination circuit 71 determines that both codes are the same code. Then, the motor control circuit 74 controls the motor 44 to stop.

Another operation of the variable magnification device of the first embodiment is as shown in FIG. 4D, when the main lens housing 1 is moved in the opposite direction to that of the first embodiment, that is, in the direction of the arrow 52 in FIGS. 4A and 4B. , and the third additional lens 50 is inserted on the optical axis on the opposite side to the first additional lens 5 and the second additional lens 7.

The above operation is performed, for example, in a copying machine capable of enlarging and reducing copying, when the first additional lens 5 and the second
By forming a reduction optical system when the additional lens 7 is inserted and forming an enlargement optical system when the third additional lens 50 is inserted, a reduction/enlargement copying machine can be obtained very easily.

As described in detail above, the present invention has the effect that even a relatively large and heavy optical element that is moved for zooming can be accurately positioned at a predetermined position by inertial force. In addition, since the main lens housing 1 is moved by the rope 22 wound around the driving pulley 43, it has the advantage that there is a large degree of freedom in designing its travel. Can be set in advance.

FIG. 5 is a perspective view showing a second embodiment of the invention. In describing this embodiment, the same or equivalent components as those of the first embodiment described above will be given the same reference numerals and the explanation will be omitted.

An eccentric cam plate 101 is further attached to the position detection pulley 40. On the cam surface of this eccentric cam plate 101, there is a mirror 10 that can slide on the rails 102, 103 along the optical axis 100 direction.
Arm member 106 attached to pedestal 105 of No. 4
roller 107 is in contact with it. Here, the roller 107 is constantly subjected to a force in the direction of contacting the cam surface of the eccentric cam 101 due to the tension of the spring 108 applied to the pedestal 105. This allows the main lens housing 1 to be rotated by the drive motor 44.
Since the eccentric cam 101 is also rotated at the same time as the position detection pulley 40 moves, the roller 107 resists the tension of the spring 108 and moves the mirror 104.
is moved in the optical axis 100 direction.

In this way, in this embodiment, the main lens housing 1 and the mirror 1 are moved by one drive motor 44.
It has the advantage that two driven optical elements of 04 can be driven.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a first embodiment of the present invention;
Figure 2 is a block diagram showing the configuration of the encoder and control circuit, Figure 3a is a diagram showing the relationship between the lever 21 and the guide plate, Figure 3b is a diagram showing the relationship between the click roller and the click plate, and Figure 4 is a diagram showing the relationship between the lever 21 and the guide plate. FIG. 1 is a schematic diagram showing the operation of the embodiment, and FIG. 5 is a perspective view showing the second embodiment of the present invention. 1...Main lens housing, 5, 7, 50...
Additional lens, 15... Click board, 18... Click lever, 21... Lever, 22... Rope,
23... Guide plate, 24... Slot opening, 40...
...Position detection pulley, 43...Driving pulley, 44...Driving motor, 61...Encoder device, 101...Eccentric cam plate, 104...Mirror, 106...Arm member.

Claims (1)

[Claims] 1. A variable magnification optical system consisting of a main lens that reciprocates along the optical axis and an additional lens that is inserted into and removed from the optical path as the main lens reciprocates, and movement of the main lens. a click member having a click groove formed of a slope inclined with respect to the direction; a click lever having a click roller that engages with the click groove and rotatably attached to the main lens; and the click lever. a positioning means for stopping the reciprocating movement of the main lens at a predetermined position; and a drive source having a drive pulley for reciprocating the main lens. and a rope having an engaging means for engaging the main lens in an intermediate part, and a rope wound around the drive pulley with a predetermined friction force in the other intermediate part, and a loop mechanism that reciprocates the main lens, the engagement means has a longitudinal direction along the running direction of the rope, and a hook member attached to the main lens has an amount of play in the running direction. a guide plate having a slot opening that is inserted such that the hook member is moved from the reference plane of the slot opening based on the movement of the main lens due to inertial force when the guide plate is stopped based on the stoppage of the drive source; It is characterized by having a relationship of d<e, where d is the amount of movement of the click groove, and e is the distance between the reference position of the click groove and the contact point of the click groove of the click roller when the drive source is stopped. A variable magnification mechanism for an optical device. 2 comprising an encoder device that outputs a movement position signal of the main lens in order to control the drive source;
Claim 1, characterized in that the other intermediate portion of the rope is wound around a position detection pulley attached to the rotating shaft of the encoder device.
The variable magnification mechanism of the optical device described in 2.