Incremental printing of symbolic information – Light or beam marking apparatus or processes – Scan of light
Reexamination Certificate
2002-12-04
2003-12-16
Tran, Huan (Department: 2861)
Incremental printing of symbolic information
Light or beam marking apparatus or processes
Scan of light
C347S245000, C347S263000, C347S257000, C347S258000
Reexamination Certificate
active
06664999
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image-recording device which records an image on a printing plate and method.
2. Description of the Related Art
Devices which record (expose) an image on an image-forming layer (photosensitive layer), which is on a support of a sheet-form printing plate (for example, a “photopolymer plate”), with a direct light beam (a laser beam) have been developed as printing plate exposure devices (image-recording devices).
In a case in which the printing plate exposure device is, for example, a so-called CTP (computer-to-plate) printing plate exposure device, the light beam is irradiated at the printing plate from a collimator lens of a recording head (exposure head), through a condensing lens. In this case, if there is a variation of temperature at the recording head, a separation (distance) between the collimator lens and the condensing lens is changed due to thermal expansion of the recording head. Conventionally, in order to keep the magnification of a recorded image at a certain magnification, the light beam incident on the condensing lens from the collimator lens can be made to be parallel. With such a structure, even if the separation between the collimator lens and the condensing lens is altered, the magnification of the recorded image does not change undesirably.
However, in cases such as when an image resolution is switched in order to change image specification or the like, it is necessary to switch the magnification of the recorded image. To do this, it is necessary for the light beam incident on the condensing lens from the collimator lens to diverge. As a result, if the separation between the collimator lens and the condensing lens changes because of a change in temperature of the recording head, there is a problematic change in the magnification of the recorded image.
Moreover, when the temperature of the recording head changes, the recording head expands or contracts, and a separation between the recording head and the printing plate changes. Accordingly, a separation between the condensing lens and the printing plate changes. Consequently, there is a problem in that a shift of focus of the recorded image occurs.
In addition, when the temperature of the recording head changes, the collimator lens and the condensing lens expand or contract in accordance with changes of temperature of the collimator lens and the condensing lens. As a result, undesired alterations in an amount of divergence of the light beam by the collimator lens and a focusing distance of the light beam from the condensing lens are caused. Consequently, the problems of a change in the magnification and a shift of focus of the recorded image occur in combination.
SUMMARY OF THE INVENTION
In consideration of the circumstances described above, an object of the present invention is to provide an image-recording device and method which can prevent a shift in magnification of a recorded image regardless of temperature variations of a recording head, even when a light beam which is incident on a condensing lens is divergent, and an image-recording device and method which can prevent a shift of focus of a recorded image regardless of temperature variations of a recording head.
An image-recording device according to a first aspect of the present invention is an image-recording device that includes: a recording head which includes a transmission component which transmits a light beam, and a condensing lens at which the light beam transmitted from the transmission component is incident, the recording head recording an image at a printing plate by irradiating the light beam through the transmission component and the condensing lens to the printing plate; a measuring component which measures one of a temperature of the recording head or a temperature of a location which is presumed to be associated with the temperature of the recording head; and an adjustment component which adjusts a separation between the transmission component and the condensing lens on the basis of the temperature measured by the measuring component.
According to the image-recording device of the first aspect, an image is recorded on a printing plate by irradiating a light beam at the printing plate through the transmission component and the condensing lens of the recording head.
The measuring component measures the temperature of the recording head and/or the temperature of the location which is presumed to be associated with the temperature of the recording head. On the basis of the measured temperature, the adjustment component adjusts the separation between the transmission component and the condensing lens. As a result, the separation between the transmission component and the condensing lens can be kept constant by the adjustment component, regardless of contraction or expansion of the recording head due to temperature variations of the recording head. In addition, even if the temperature of the transmission component changes due to temperature variations of the recording head, such that the transmission component expands or contracts and thus an amount of divergence of the light beam from the transmission component is altered, the adjustment component can adjust the separation between the transmission component and the condensing lens, such that this alteration of the amount of divergence of the light beam incident on the condensing lens from the transmission component can be eliminated.
Accordingly, even when the light beam incident on the condensing lens from the transmission component is divergent, a shift in the magnification of the recorded image can be prevented regardless of temperature variations of the recording head (without controlling the temperature of the recording head (the transmission component)).
An image-recording device according to a second aspect of the present invention is an image-recording device that includes: a recording head which includes a condensing lens, the recording head recording an image at a printing plate by irradiating a light beam from the condensing lens to the printing plate; a measuring component which measures one of a temperature of the recording head or a temperature of a location which is presumed to be associated with the temperature of the recording head; and a focus adjustment component which adjusts a separation between the condensing lens and the printing plate on the basis of the temperature measured by the measuring component.
According to the image-recording device of the second aspect, an image is recorded on a printing plate by irradiating a light beam at the printing plate from the condensing lens of the recording head.
In this aspect, the measuring component measures the temperature of the recording head and/or the temperature of the location which is presumed to be associated with the temperature of the recording head. On the basis of the measured temperature, the focus adjustment component adjusts the separation between the condensing lens and the printing plate. As a result, even if, when the recording head expands or contracts due to temperature variations of the recording head, such that the separation between the recording head and the printing plate changes and hence the separation between the condensing lens and the printing plate changes, the separation between the condensing lens and the printing plate can be kept constant by the focus adjustment component. In addition, even if the temperature of the condensing lens changes due to temperature variations of the recording head, such that the condensing lens expands or contracts and thus a focusing distance of the light beam from the condensing lens is altered, the focus adjustment component can adjust the separation between the condensing lens and the printing plate, such that this alteration (shift) of the focusing distance of the light beam from the condensing lens can be eliminated.
Accordingly, even when the temperature of the recording head changes, a loss (shift) of focus of the recorded image can be prevented, without controlling
Miyagawa Ichirou
Miyamaru Fumiaki
Ohba Masahiro
Taiyo, Nakatima & Kato
Tran Huan
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