JP2602705B2 - Projection illuminance adjustment device of projection magnification measurement device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection illuminance adjusting device of a projection magnification measuring device for projecting an original film in an enlarged / reduced state and measuring the magnification.

[Prior Art] In color separation work using a printing plate making scanner,
Paste the original film such as a color film on the scanning drum of the scanner, instruct the scanner the magnification corresponding to the finished print size of the original film indicated on the layout designation sheet,
The original film is separated into four color plates of yellow, magenta, cyan and black.

2. Description of the Related Art Conventionally, a projection magnification measuring device has been used as a device for projecting an image of an original film on a sample (underlay) drawn on a designated layout sheet and projecting the image on an enlarged or reduced scale and measuring the magnification.

This projection magnification measurement device, a light source for projecting an image of the film, a film holding unit that holds the film,
A lens holding unit for holding the lens, a projection surface on which an image of the film is projected via the lens, position information (h) and (a) of the film with respect to the projection surface or the lens, and position information (b) of the lens with respect to the projection surface ) And a magnification calculator for calculating the projection magnification (t) using at least two pieces of information of the focal length information (f) of the lens. The magnification calculator calculates the projection magnification t by, for example, t = b / a.

[Problems to be Solved by the Invention] However, the conventional projection magnification measuring apparatus has the following problems.

When the distance between the light source and the projection surface increases at a high magnification or the like, the illuminance on the projection surface decreases, and the projected image is dark and difficult to see.

Conversely, when the distance between the light source and the projection surface decreases at low magnification or the like, the illuminance of the projection surface increases, and the projected image becomes dazzling and difficult to see.

If the light transmittance of the original film is poor and the amount of light transmitted through the film is small, the illuminance on the projection surface is low, and the projected image is dark and difficult to see.

Conversely, if the light transmittance of the original film is excessively high and the amount of light transmitted through the film increases, the illuminance on the projection surface increases, making the projected image dazzling and difficult to see.

An object of the present invention is to always easily adjust the illuminance of a projection surface even when the height of a light source or a document changes.

[Means for Solving the Problems] The present invention according to claim 1, a light source for projecting an image of a film, a film holding unit for holding a film, a lens holding unit for holding a lens, A projection plane on which an image is projected via a lens, and position information (h) and (a) of the film with respect to the projection plane or the lens, position information (b) of the lens with respect to the projection plane, and focal length information (f) of the lens And a magnification calculator for calculating a projection magnification (t) using at least two pieces of information among the light sources, provided in an optical path between the light source and the projection surface, and A light control plate that can be limited, a light source position equivalent amount detection unit that detects a light source position equivalent amount corresponding to the distance that the light source makes with respect to the projection surface, and a light source position equivalent amount detected by the light source position equivalent amount detection unit. Great place In this case, there is provided a dimming operation unit that weakens the degree of restriction of the amount of transmitted light by the light control plate and increases the degree of restriction of the amount of transmitted light by the light control plate when the equivalent amount of the light source position is small. is there.

According to the present invention, a light source for projecting an image of a film, a film holding unit for holding a film, a lens holding unit for holding a lens, and an image of the film are projected through a lens. Using a projection plane and at least two pieces of information of film position information (h) and (a) with respect to the projection plane or the lens, lens position information (b) with respect to the projection plane, and lens focal length information (f) A projection magnification measuring device having a magnification calculator for calculating a projection magnification (t) by using a light control plate provided in an optical path between a light source and a projection surface and capable of restricting the amount of transmitted light; Based on the detection results of the film transmission light amount detection unit and the film transmission light amount detection unit that detects the transmission light amount, if the film transmission light amount is small, the degree of restriction of the transmission light amount by the light control plate is reduced, and the film transmission The amount is one that was set to be provided with a dimming operation member to enhance the restriction degree of the transmitted light amount by the dimming plate when a large becomes.

[Operation] According to the present invention described in claim 1, the following operation is provided.

(A) When the distance between the light source and the projection plane increases at a high magnification or the like, the light source position equivalent amount detection unit detects this change in distance, and the dimming operation unit transmits the light through the dimming plate according to the detection result. The degree of restriction on the amount of light is reduced, and a larger amount of light from the light source is transmitted to the projection surface. This recovers the tendency of the illuminance on the projection surface to decrease, and forms an appropriate illuminance on the projection surface.

(B) Conversely, when the distance between the light source and the projection plane decreases at a low magnification or the like, the light source position equivalent amount detection unit detects this change in distance, and the dimming operation unit changes according to the detection result. , And the movement of light from the light source side to the projection surface side is further restricted. This suppresses the tendency of the illuminance on the projection surface to increase, and forms an appropriate illuminance on the projection surface.

According to the second aspect of the present invention, the following operations are provided.

(A) When the light transmittance of the original film is poor and the amount of light transmitted through the film is small, the film transmitted light amount detection unit detects the change in the transmitted light amount, and the light control operation unit detects the change in the transmitted light amount based on the detection result. Is reduced, and a larger amount of light on the light source side is transmitted to the projection surface side. This allows
The tendency of the illuminance on the projection surface to decrease is restored, and an appropriate illuminance is formed on the projection surface.

(B) Conversely, when the light transmittance of the original film is excessively high and the amount of light transmitted through the film increases, the film transmitted light amount detection unit detects a change in the transmitted light amount, and the light control operation unit adjusts the light intensity according to the detection result. The degree of restriction on the amount of transmitted light by the light plate is increased, and the movement of light from the light source side to the projection plane side is further restricted. This suppresses the tendency of the illuminance on the projection surface to increase, and forms an appropriate illuminance on the projection surface.

That is, according to the present invention, the illuminance on the projection surface can always be easily corrected even when the height of the light source or the document changes.

FIG. 1 is a schematic diagram showing an embodiment of the present invention, FIG. 2 is a control block diagram of FIG. 1, FIG. 3 is a schematic diagram showing a mechanical configuration of FIG. 1, and FIG. FIG. 5 is a schematic diagram showing another embodiment of the present invention, FIG. 5 is a diagram showing an example of the relationship between the light source distance L and the light control plate transmission light amount K, and FIG. FIG. 3 is a diagram illustrating an example of a relationship with a light amount K.

The projection magnification measuring device 10 is, as shown in FIGS.
A light source 12 for projecting an image of the original film 11, a film holding unit 13 for holding the film 11, a lens holding unit 15 for holding a lens 14, and a projection in which the image of the film 11 is projected through the lens 14. Surface 16. 17 is a mirror, 18 is a light control plate, and 19 is a condenser lens.

The light source 12, the film holder 13, and the lens holder 15 are built in a lamp house 20. Lamp house 20, frame 21
It is supported to be able to move up and down freely. A drive wheel 22 is provided on the frame 21, and the flexible wrapping body 23 is wound around the drive wheel 22 without slipping. One end of the winding body 23 is connected to the lamp house 20, and a counterweight 24 is connected to the other end of the winding body 23. The driving wheel 22 is rotated by a motor 25,
The lamp house 20 is raised and lowered, and the lens 14 is
(B) can be adjusted. The adjustment of the position of the lamp house 20, and thus the distance (b), is detected by an encoder 26 connected to a motor 25.

The film holding unit 13 is supported by a feed screw shaft 27 supported by the lamp house 20, and can be moved up and down. The feed screw shaft 27 is rotated by a motor 28 to raise and lower the film holding unit 13 so that the distance (a) of the film 11 to the lens 14 can be adjusted. The position information of the film holding unit 13, that is, the distance (a) is detected by an encoder 29 connected to a motor 28. The detection results of the encoders 26 and 29 are input to the magnification calculator 30, where the distance (h) of the film 11 to the projection plane 16 is detected.

Light source 12, mirror 17, ground glass 18, condenser lens 19
Is moved up and down integrally with the film holding unit 13 by supporting means (not shown). Accordingly, the distance between the film 11 and the light source 12 is kept constant (l). Therefore, the distance (L) of the light source 12 to the projection surface 16 is determined by the magnification calculator 30 by the detection results of both encoders 26 and 29 and the distance. It will be detected based on (l).

Here, the condition in which the image of the film 11 matches the sample placed on the projection surface 16 and focuses on the condition that when the focal length of the lens 14 is f and the projection magnification is t, 1 / a + 1 / b = 1 / f (1) b = ha (2) t = b / a (3) h = 2f + tf + f / t (4) In the projection magnification measuring device 10, a sample is placed on the projection surface 16, and the film house 13 is moved up and down with respect to the lamp house 20 and the lamp house 20 to move the film 11 up and down.
When the projected image matches the sample and focuses, the lamp house 20 and the film holder 13 are stopped at that position, and then
By operating the magnification calculator 30, the projection surface 16 or the lens 14
Information (h) and (a) of the film 11 with respect to the projection plane
Position information (b) of the lens 14 with respect to 16 and the lens 14
The projection magnification (t) can be calculated by the above equations (1) to (4) using at least two pieces of the focal length information (f).

However, the projection magnification measuring device 10 includes a light source 12 and a projection surface 16.
The light control plate 18 as described above, which can limit the amount of transmitted light, is provided in the optical path between the light control plate 18 and the light control plate 18. As the light control plate 18, for example, “Angle 21” (trade name, manufactured by Nippon Sheet Glass Co., Ltd.) is used, and the amount of transmitted light can be changed by adjusting the angle of intersection with the optical path. In FIG. 1, reference numeral 34 denotes a dimming motor for adjusting an intersection angle of the dimming plate 18 with respect to an optical path, and 35 denotes a rotation transmitting device.

Further, the projection magnification measuring device 10 uses the distance (L) of the light source 12 with respect to the projection surface 16 as the light source position equivalent amount, and also serves as the magnification calculation unit 30 as the light source position equivalent amount detection unit. The distance (L) can be detected by calculation based on the detection results of both encoders 26 and 29 and the distance (l).

Further, the projection magnification measuring device 10 includes a dimming operation unit 31 (CPU)
When the light source distance is large, the dimming operation unit 31 weakens the degree of restriction of the amount of transmitted light by the dimming plate 18 based on the detection result of the distance (L) in the magnification calculating unit 30, and the light source position is changed. If the distance is smaller, the degree of restriction of both transmitted light by the light control plate 18 is increased. 32 is a D / A converter, and 33 is an amplifier.
FIG. 5 is a diagram showing an example of a relationship between a light source distance L and a light control plate transmitted light amount K.

 Next, the operation of the above embodiment will be described.

 According to the above embodiment, the following operations are provided.

(A) When the distance between the light source 12 and the projection surface 16 increases at a high magnification or the like, the magnification calculation unit 30 detects this change in distance, and the dimming operation unit 31 linked to this detection result adjusts the dimming. The degree of restriction of the amount of transmitted light by the plate 18 is reduced, and more light from the light source is transmitted to the projection surface. This allows the projection plane
The tendency of the illuminance of 16 to decrease is restored, and an appropriate illuminance is formed on the projection surface 16.

(B) Conversely, when the distance between the light source 12 and the projection surface 16 decreases at a low magnification or the like, the magnification calculation unit 30 detects this change in distance, and the dimming operation unit 31 interlocked with this distance change. The degree of restriction on the amount of transmitted light by the light control plate 18 is increased, and the movement of light from the light source side to the projection surface side is restricted to a greater extent. This suppresses the tendency of the illuminance on the projection surface 16 to increase, and forms an appropriate illuminance on the projection surface 16.

In the above embodiment, the magnification calculation unit 30 is also used as the light source position equivalent amount detection unit of the present invention, and both input encoders 26,
The light source light amount was controlled based on the magnitude of the light source distance L itself calculated based on the detection result of 29 and the distance (l). However, the distance (L) of the light source 12 to the projection plane 16 may be directly detected by a single detector as the light source position equivalent amount detection unit. For example, if the lens 14 and the light source 12 are integrally moved up and down, the position information (L) of the light source 12 can be directly detected from the single encoder 26. Further, in the embodiment of the present invention, for example, a projection magnification or the like having a certain correspondence with the change in the light source position may be used as the light source position equivalent. In this case, it is sufficient to use the magnification calculator 30 as the light source position equivalent amount detector in the same manner as in the embodiment.

In the projection magnification measuring device 10, a film transmitted light amount detection unit 41 is provided on the side opposite to the light source of the film holding unit 13. The film transmitted light amount detection unit 41 detects the transmitted light amount of the film 11, and transfers the detection result to the light control operation unit 31 described above. Based on the detection result of the film transmitted light amount detection unit 41, the light control operation unit 31 weakens the degree of limitation of the transmitted light amount by the light control plate 18 when the film transmitted light amount is small, and adjusts the light transmission amount when the film transmitted light amount is large. The degree of restriction on the amount of transmitted light by the light plate 18 is increased. FIG. 6 is a diagram showing an example of the relationship between the film transmitted light amount P and the light control plate transmitted light amount K.

Therefore, in the projection magnification measuring device 10,
(A) When the light transmittance of the original film 11 is poor and the amount of light transmitted through the film is small, the film transmitted light amount detection unit 41 detects a change in the transmitted light amount, and the light control operation unit 31 linked to this detection result controls the light control. Weakened the limit of transmitted light quantity by plate 18,
More light from the light source is transmitted to the projection surface. Thereby, the tendency of the illuminance on the projection surface 16 to decrease is recovered, and an appropriate illuminance is formed on the projection surface 16.

(B) Conversely, the light transmittance of the original film 11 is excessively good,
When the amount of transmitted light of the film increases, the transmitted light amount detecting section 41 of the film detects the change of the transmitted light quantity, and the dimming operation section 31 linked to the detection result strengthens the degree of restriction of the transmitted light quantity by the dimming plate 18 and the light source side. The movement of light from the surface to the projection surface side is restricted to a greater extent. This suppresses the tendency of the illuminance on the projection surface 16 to increase, and forms an appropriate illuminance on the projection surface 16.

FIG. 4 shows another embodiment of the present invention. This embodiment is different from the embodiment of FIG.
That is, the light control plate 51 is provided. The light control plate 51 is made of ground glass, and can reciprocate in a direction crossing the optical path by a light control motor 52, a pinion 53, and a rack 54. That is, the light control plate
51 is a light source position equivalent amount detecting unit 30 (magnification calculating unit) or a film transmitted light amount detecting unit, as in the previous embodiment.
The light control operation unit 31 linked to 41 controls the light control motor 52,
When the light source distance becomes large at high magnification or when the light transmittance of the original film is poor, the light control plate 51 is moved out of the optical path from the position shown in the figure, and as a result, the light control by the light control plate 51 is stopped. Then, a large amount of light is given to the projection surface. Conversely, when the light source distance is reduced at low magnification or the like, or when the light transmittance of the original film is excessively improved, the light control plate 51 is fixed to the position in the optical path shown in the drawing, and as a result, the light control plate 51 Limit the amount of transmitted light and limit the movement of light to the projection surface.

In each of the above embodiments, the dimming operation such as the rotation and the reciprocating motion for the dimming operation of the dimming plates 18 and 51 is not automatically controlled as in the embodiment, but is manually operated by an operator.
It may be based on an electric switch operation by an operator or the like.

[Effects of the Invention] As described above, according to the present invention, the illuminance of the projection surface can always be easily optimized even when the height of the light source or the document changes.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing one embodiment of the present invention, and FIG.
FIG. 3 is a schematic diagram showing a mechanical configuration of FIG. 1, FIG. 4 is a schematic diagram showing another embodiment of the present invention,
FIG. 5 is a diagram showing an example of the relationship between the light source distance L and the light control plate transmitted light amount K, and FIG. 6 is a diagram showing an example of the relationship between the film transmitted light amount P and the light control plate transmitted light amount K. . 10: Projection magnification measuring device, 11: Original film, 12: Light source, 13: Film holder, 14: Lens, 15: Lens holder, 16: Projection surface, 18: Dimmer , 26, 29 ... Encoder, 30 ... Magnification calculation unit (light source position equivalent amount detection unit), 31 ... Light control operation unit, 41 ... Film transmitted light amount detection unit, 51 ... Light control plate.

Claims (2)

(57) [Claims] A light source for projecting an image of a film;
A film holding unit for holding a film, a lens holding unit for holding a lens, a projection surface on which an image of the film is projected via the lens, and positional information (h), (a), and (h) of the film with respect to the projection surface or the lens. A projection magnification measurement unit having a magnification calculator for calculating a projection magnification (t) using at least two pieces of information among the position information (b) of the lens with respect to the projection surface and the focal length information (f) of the lens. In the device, a light control plate provided in an optical path between the light source and the projection surface and capable of limiting the amount of transmitted light, and a light source position equivalent amount for detecting a light source position equivalent amount corresponding to a distance between the light source and the projection surface Based on the detection result of the detection unit and the light source position equivalent amount detection unit,
A dimming operation unit is provided to weaken the degree of limiting the amount of transmitted light by the dimming plate when the equivalent amount of the light source is large, and increase the degree of limitation of the amount of transmitted light by the dimming plate when the equivalent amount of the light source is small. A projection illuminance adjusting device for a projection magnification measuring device, comprising: 2. A light source for projecting an image on a film,
A film holding unit for holding a film, a lens holding unit for holding a lens, a projection surface on which an image of the film is projected via the lens, and positional information (h), (a), and (h) of the film with respect to the projection surface or the lens. A projection magnification measurement unit having a magnification calculator for calculating a projection magnification (t) using at least two pieces of information among the position information (b) of the lens with respect to the projection surface and the focal length information (f) of the lens. In the device, a light control plate provided in an optical path between a light source and a projection surface and capable of limiting a transmitted light amount, a film transmitted light amount detecting unit for detecting a transmitted light amount of a film, and a detection result of the film transmitted light amount detecting unit. When the amount of light transmitted through the film is small, the degree of restriction of the amount of transmitted light by the light control plate is reduced, and when the amount of light transmitted through the film is large, the degree of restriction of the amount of transmitted light by the light control plate is increased. Projection illumination adjuster projection magnification measuring apparatus characterized by comprising a part.