Electrophotography – Control of electrophotography process – Control of developing
Reexamination Certificate
1999-12-28
2001-08-21
Chen, Sophia S. (Department: 2852)
Electrophotography
Control of electrophotography process
Control of developing
C118S689000, C399S064000
Reexamination Certificate
active
06278850
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device of measuring the concentration of a developer liquid used in a liquid-type printer, which can sense the concentration of a developer liquid by measuring light transmittance.
2. Description of the Related Art
In liquid electrophotographic printers such as liquid-type laser printers, a latent electrostatic image is formed on a photosensitive medium by scanning laser beams thereunto, and then developed by a developer unit using a developer liquid containing toners having a predetermined color. The resultant toner image is transferred on a print paper, resulting in a color image on the print paper. Such liquid electrophotographic printers need a device of measuring the concentration of a developer liquid, to maintain the concentration of the developer liquid supplied to the photosensitive medium within a predetermined range.
Referring to
FIG. 1
, a conventional device of measuring the concentration of a developer liquid is disposed on a developer liquid supply pathway, which includes a pair of transparent members
1
and
3
along the space of which a developer liquid D flows, and a light emitting device
5
and a light receiving device
7
facing each other while the pair of transparent members
1
and
3
are interposed therebetween. Thus, in measuring the developer liquid, the light receiving device
7
detects the concentration of a developer liquid by receiving light passed through the developer liquid D after being emitted from the light emitting device
5
.
In a concentration measuring device having the above configuration, when a developer liquid D is black, which has a relatively low light transmittance compared to other colors, the transparent members
1
and
3
must be spaced by approximately 0.1 mm or less to detect a difference in light transmittance according to the concentration of the developer liquid D. However, as the space between the transparent members
1
and
3
becomes narrow, the flow rate of the developer liquid becomes slow. Accordingly, toner particles stick to the inner walls of the transparent members
1
and
3
, thereby lowering light transmittance. Furthermore, it is not possible to remove the toner particles from the inner walls of the transparent members
1
and
3
.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an apparatus for measuring the concentration of a developer liquid for a liquid-type electrophotographic printer, in which sticking of toner particles to the inner walls of a developer liquid pathway can be prevented although the developer liquid pathway is narrow, so that the concentration of a developer liquid having a low light transmittance can also be measured.
In an aspect of the present invention, there is provided a device of measuring the concentration of developer liquid for a liquid-type printer, comprising: a container having a discharge portion; first and second rotary members rotatably installed in the container with a predetermined space; a supply portion for supplying the developer liquid containing toner particles and liquid carrier into the space between the first and second rotary members; and a concentration detector for detecting the concentration of the developer liquid by emitting light onto the developer liquid flowing along the space between the first and second rotary members, and receiving the light passed through the developer liquid.
In one embodiment, the concentration detector comprises: transparent members formed at at least parts of the first and second rotary members; a light source installed in the first rotary member, for emitting light toward the second rotary member; and a photodetector installed in the second rotary member, facing the light source installed in the first rotary member, for detecting the light emitted from the light source and passed through the developer liquid flowing along the space between the first and second rotary members.
In another embodiment, the concentration detector comprises: a reflection member formed at at least a part of the surface of the first rotary member; a transparent member formed at at least a part of the second rotary member, corresponding to the reflection member; a light source installed in the second rotary member, for emitting light toward the transparent member; and a photodetector installed near the light source in the second rotary member, for receiving the light reflected by the reflection member, which has been emitted from the light source and passed through the developer liquid flowing along the space between the first and second rotary members.
Preferably, the concentration measuring device further comprises a cleaning member installed in contact with the first and/or second rotary members, for removing toner particles stuck to the surface of the first and/or second rotary members with the rotation of the first and/or rotary members.
REFERENCES:
patent: 3789794 (1974-02-01), Smith et al.
patent: 4204766 (1980-05-01), Harada
patent: 5933685 (1999-08-01), Yoo
patent: 6091914 (2000-07-01), Yoo
patent: 48-8301 (1973-03-01), None
patent: 49-66351 (1974-06-01), None
patent: 56-10233 (1981-02-01), None
patent: 5-332926 (1993-12-01), None
patent: 8-128898 (1996-05-01), None
Chen Sophia S.
Samsung Electronics Co,. Ltd.
Sughrue Mion Zinn Macpeak & Seas, PLLC
LandOfFree
Device of measuring concentration of developer liquid for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device of measuring concentration of developer liquid for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device of measuring concentration of developer liquid for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2532352